WorldWideScience

Sample records for funktionsanalyse mittels mrt

  1. Cryotherapy of malignant tumors: MR imaging in comparison with pathological changes in mice; Kryotherapie maligner Tumoren: Untersuchungen mittels MRT im Tierexperiment und Vergleich mit morphologischen Veraenderungen

    Energy Technology Data Exchange (ETDEWEB)

    Romaneehsen, B.; Anders, M.; Roehrl, B.; Hast, H.J.; Schiffer, I.; Neugebauer, B.; Teichmann, E.; Schreiber, W.G.; Thelen, M. [Mainz Univ. (Germany). Klinik und Poliklinik fuer Radiologie; Hengstler, J.G. [Mainz Univ. (Germany). Inst. fuer Toxikologie

    2001-07-01

    Aim of our study was to investigate the efficacy of 7 F cryoprobes for percutaneous use morpho- and histologically, to examine the role of apoptosis after cryotherapy, and to compare contrast-enhanced MRI with histopathological findings at different time intervals in a tumor-mouse model. Methods: Percutaneous cryotherapy was performed in 15 immunocompromised nude mice with subcutaneously implanted tumors using the non-small-cell lung cancer cell line Lu 1. In group a) 7 mice were sacrificed after definite time intervals and histological examinations were done for evaluation of necrosis and apoptosis (HE; TUNEL assay); 2 mice are in long-term follow-up. In group b) in 6 mice tumor destruction and perfusion before and after freezing were investigated with native and contrast-enhanced MR imaging (T{sub 1}- and T{sub 2}-weighted spin-echo) and compared with histopathological findings. Histological control were done in 2 untreated mice. Results: We observed fast tumor-reduction within two weeks (ca. 50%). On long-term follow-up (> 6 months) no recurrence has been noticed so far. Tumors were well vascularized prior to treatment and did not-show contrast enhancement an any time after cryotherapy. A narrow contrast-enhanced zone was seen on the tumor border subcutaneously as a sign of peripheral hyperemia and central vascular stasis after cryotherapy. On histology there was evidence of both apoptosis and necrosis. (orig.) [German] Evaluierung der Durchfuehrbarkeit und Effizienz einer perkutanen Kryotherapie mittels 7-F-Kryosonde in Nacktmaeusen. Erheben des histopathologischen Befundes der Kryolaesion nach definierten Zeitintervallen und Ueberpruefung einer moeglichen Rolle der Apoptose nach Kryotherapie. Darstellung morphologischer Veraenderungen des Tumors und des angrenzenden Gewebes im Anschluss an die Kryotherapie mittels kontrastmittelunterstuetzter MRT. Methodik: Zweiminuetige Kryotherapie subkutan implantierter Tumoren eines nicht-kleinzelligen Bronchialkarzinoms

  2. Determination of left ventricular heart volume by fast MRI in breath-hold technique: how different are quantitative ventricular angiography, quantitative MRI, and visual echocardiography?; Linksventrikulaere Herzvoluminabestimmung mittels schneller MRT in Atemanhaltetechnik: Wie unterschiedlich sind quantitativer Herzkatheter, quantitativer MRT und visuelle Echokardiographie?

    Energy Technology Data Exchange (ETDEWEB)

    Rominger, M.B.; Bachmann, G.F. [Giessen Univ. (Germany). Diagnostische Radiologie; Kerckhoff-Klinik GmbH, Bad Nauheim (Germany). Projektgruppe Magnetresonanztomographie; Pabst, W. [Giessen Univ. (Germany). Inst. fuer Medizinische Informatik; Ricken, W.W. [Kerckhoff-Klinik GmbH, Bad Nauheim (Germany). Projektgruppe Magnetresonanztomographie; Dinkel, H.P.; Rau, W.S. [Giessen Univ. (Germany). Diagnostische Radiologie

    2000-01-01

    . Ergebnisse: Der HK ueberschaetzte die EF im Vergleich zur MRT um 8,4%, Echo unterschaetzte sie im Mittel um 5,6%. Der Toleranzbereich der EF von MRT und HK betrug {+-}23,8%, vom MRT und Echo {+-}18% und von Echo und HK {+-}19,4%. Signifikante Mittelwertunterschiede zwischen HK und MRT in der Herzvoluminabestimmung ergaben sich fuer EDV, SV und HZV, nicht aber fuer ESV. Die groesste Uebereinstimmung der EF bestand in der Gruppe mit DCM, die schlechteste in der Gruppe mit KV. Schlussfolgerung: Deutliche zufaellige und systematische Abweichungen sind im Methodenvergleich von MRT, Echo und HK zu erwarten. Fuer Therapieentscheidung und Verlaufskontrolle sollten die Methoden nicht bedenkenlos ausgetauscht werden. (orig.)

  3. Functional MRI in schizophrenia. Diagnostics and therapy monitoring of cognitive deficits of schizophrenic patients by functional MRI; Funktionelle MRT bei Schizophreniepatienten. Diagnostik und Therapiemonitoring kognitiver Defizite schizophrener Patienten mittels funktioneller MRT

    Energy Technology Data Exchange (ETDEWEB)

    Furtner, J.; Prayer, D. [Medizinische Universitaet Wien, Univ.-Klinik fuer Radiodiagnostik, Wien (Austria); Sachs, G. [Medizinische Universitaet Wien, Univ.-Klinik fuer Psychiatrie und Psychotherapie, Wien (Austria)

    2010-02-15

    Cognitive impairments are core psychopathological components of the symptomatic of schizophrenic patients. These dysfunctions are generally related to attention, executive functions and memory. This report provides information on the importance of using functional magnetic resonance imaging (fMRI) for the diagnostics and therapy monitoring of the different subtypes of cognitive dysfunctions. Furthermore, it describes the typical differences in the activation of individual brain regions between schizophrenic patients and healthy control persons. This information should be helpful in identifying the deficit profile of each patient and create an individual therapy plan. (orig.) [German] Kognitive Defizite sind ein zentraler Bestandteil der Symptomatik schizophrener Patienten. Diese Defizite betreffen v. a. die Aufmerksamkeit, exekutive Funktionen sowie das Gedaechtnis. Der vorliegende Beitrag zeigt den Stellenwert der funktionellen Magnetresonanztomographie (fMRT) in Hinblick auf Diagnostik und Therapiemonitoring der unterschiedlichen kognitiven Teilbereiche auf. Darueber hinaus werden die Unterschiede in Bezug auf die Aktivierung der einzelnen Gehirnareale zwischen schizophrenen Patienten und gesunden Kontrollpersonen dargestellt. Diese Informationen sollen helfen, in der Praxis ein Profil der kognitiven Leistungsreduktionen sowie ein darauf angepasstes Therapiekonzept zu erstellen. (orig.)

  4. MR imaging of gastric wall layers in vitro: correlation to the histologic wall structure; Experimentelle Darstellung der Schichten der Magenwand mittels MRT: Korrelation mit dem histologischen Wandaufbau

    Energy Technology Data Exchange (ETDEWEB)

    Lubienski, A.; Grenacher, L.; Schipp, A.; Duex, M. [Radiologische Klinik, Abt. Radiodiagnostik, Ruprecht-Karls-Univ. Heidelberg (Germany); Reith, W. [Abt. fuer Neuroradiologie der Radiologischen Universitaetsklinik, Univ. Saarland (Germany); Mechtersheimer, G. [Inst. fuer Allgemeine Pathologie, Ruprecht-Karls-Univ. Heidelberg (Germany)

    2002-04-01

    vier Magenwandschichten auf den MR-Bildern voneinander differenziert werden. Der direkte Vergleich dieser Magenwandschichten mit den korrespondierenden histologischen Schnitten ergab von lumenseitig betrachtet folgende Korrelation: 1. Schicht: intermediaeres Signal - Mukosa, 2. Schicht: hypointenses Signal - Lamina muscularis mucosae, 3. Schicht: hyperintenses Signal - Submukosa, 4. Schicht: intermediaeres Signal - Muscularis propria. Schlussfolgerungen: Magnetresonanztomographisch sichtbare Magenwandschichten wurden dem anatomischen Wandaufbau des Magens mit Erfolg zugeordnet. Damit besteht erstmals die Moeglichkeit, die Tiefeninfiltration eines Magenkarzinoms mit Hilfe hochaufgeloester MR-Aufnahmen zu beurteilen. Diese Einschaetzung gilt ausdruecklich nicht fuer die Subserosa und Serosa, da ueber die Darstellbarkeit dieser sehr variablen Wandschichten durch die MRT noch keine Aussage zu treffen ist. (orig.)

  5. Ultrasound-guided image fusion with computed tomography and magnetic resonance imaging. Clinical utility for imaging and interventional diagnostics of hepatic lesions; Ultraschallgestuetzte Bildfusion mittels CT und MRT. Klinische Bedeutung fuer die bildgebende und interventionelle Diagnostik von Leberlaesionen

    Energy Technology Data Exchange (ETDEWEB)

    Clevert, D.A.; Helck, A.; Paprottka, P.M.; Trumm, C.; Reiser, M.F. [Klinikum der Ludwig-Maximilians-Universitaet, Campus Grosshadern, Institut fuer Klinische Radiologie, Muenchen (Germany); Zengel, P. [Klinikum der Ludwig-Maximilians-Universitaet, Campus Grosshadern, Klinik fuer Hals-, Nasen- und Ohrenheilkunde, Muenchen (Germany)

    2012-01-15

    Abdominal ultrasound is often the first-line imaging modality for assessing focal liver lesions. Due to various new ultrasound techniques, such as image fusion, global positioning system (GPS) tracking and needle tracking guided biopsy, abdominal ultrasound now has great potential regarding detection, characterization and treatment of focal liver lesions. Furthermore, these new techniques will help to improve the clinical management of patients before and during interventional procedures. This article presents the principle and clinical impact of recently developed techniques in the field of ultrasound, e.g. image fusion, GPS tracking and needle tracking guided biopsy and discusses the results based on a feasibility study on 20 patients with focal hepatic lesions. (orig.) [German] Bei der Bildfusion von Ultraschall mit anderen schnittbildgebenden Verfahren (CT, MRT) handelt es sich um ein relativ neuartiges Verfahren, welches unter Studienbedingungen jedoch bereits erfolgreich eingesetzt wurde. In der folgenden Machbarkeitsstudie soll der Nutzen weiterfuehrender Anwendungen der sonographischen Bildfusion, dem so genannten Global-Positioning-System- (GPS-) und Needle-Tracking, untersucht werden. Dabei handelt es sich um Instrumente, die insbesondere die Diagnostik und das Staging (GPS-Tracking) bzw. die bioptische Abklaerung (Needle-Tracking) von Patienten mit fokalen Leberlaesionen erleichtern. In diesem Artikel werden das Prinzip und die Anwendungsmoeglichkeiten dieser neuen Techniken anhand konkreter Beispiele in einem Kollektiv von 20 Patienten mit fokalen Leberlaesionen vorgestellt und erlaeutert. (orig.)

  6. Clinical dictionary of MRT

    International Nuclear Information System (INIS)

    Herborn, C.U.; Zink, C.

    2007-01-01

    MRT is the method of choice in many clinical problems. It is also one of the most complex imaging procedures, requiring much technical and physical knowledge and also detailed knowledge of the signal response of physiological and pathological tissues in the many variants of contrast enhancement, image reconstruction and image processing. In 2006, the pocket dictionary of MRT was published by the same publisher. It met with much positive response, which induced the publication of this new dictionary. With more than 3000 terms and definitions elaborated in cooperation with an excellent practician, the clinical applications of MRT are illustrated by typical findings and examples. (orig.)

  7. Evaluation of passive cardiomyoplasty using left- and right-ventricular volume measurements by EBCT and MRI in patients with chronic congestive heart failure; Evaluierung der passiven Kardiomyoplastie mittels links- und rechtsventrikulaerer EBCT- und MRT-Volumetrie bei Patienten mit chronischer Herzinsuffizienz

    Energy Technology Data Exchange (ETDEWEB)

    Lembcke, A.; Enzweiler, C.N.H.; Wiese, T.H.; Kivelitz, D.E.; Rogalla, P.; Hamm, B. [Inst. fuer Radiologie, Universitaetsklinikum Charite, Campus Charite Mitte, Humboldt Univ. zu Berlin (Germany); Hotz, H.; Dushe, S.; Konertz, W. [Klinik fuer Kardiovaskulaere Chirurgie, Universitaetsklinikum Charite, Campus Charite Mitte, Humboldt Univ. zu Berlin (Germany)

    2003-08-01

    Purpose: To evaluate the efficacy of passive cardiomyoplasty with the determination of biventricular volumes, global systolic function as well as left-ventricular muscle mass. Materials and Methods: In 19 patients with congestive heart failure of idiopathic or ischemic origin, a polyester mesh-graft was implanted around both ventricles for stabilization and functional support. Before and three months after surgery, 15 patients underwent EBCT and 4 patients with impaired renal function underwent MRI, for the evaluation of the volume and ejection fraction of both ventricles. Results: EBCT demonstrated a decrease from 385 to 310 ml in LV-EDV, from 312 to 242 ml in LV-ESV, from 209 to 160 ml in RV-EDV and from 149 to 87 ml in RV-ESV, and an increase from 20 to 26% in LV-EF and from 37 to 50% in RV-EF as well as a reduction of LV-MM from 300 to 274 g (p < 0.05 each). Similar results were obtained by MRI. Conclusion: Following passive cardiomyoplasty, EBCT and MRI revealed an improvement of the global systolic function as well as a reduction of biventricular volumes and left-ventricular muscle mass. (orig.) [German] Ziel: Evaluierung des Therapieerfolges der passiven Kardiomyoplastie durch Bestimmung der biventrikulaeren Volumina und global systolischen Funktion sowie der linksventrikulaeren Muskelmasse. Methoden: Bei 19 Patienten mit idiopathisch und ischaemisch bedingter Herzinsuffizienz erfolgte die Implantation eines Polyesternetzes um die Ventrikel zu deren Stabilisierung und funktioneller Unterstuetzung. Praeoperativ sowie drei Monate postoperativ wurden bei 15 Patienten durch EBCT und bei 4 Patienten mit eingeschraenkter Nierenfunktion durch MRT die Volumina und Ejektionsfraktion beider Ventrikel sowie die linksventrikulaere Muskelmasse bestimmt. Ergebnisse: Die EBCT zeigte eine Abnahme des LV-EDV von 385 auf 310 ml, des LV-ESV von 312 auf 242 ml, des RV-EDV von 209 auf 160 ml und des RV-ESV von 149 auf 87 ml, eine Zunahme der LV-EF von 20 auf 26% und der RV

  8. Computer-assisted operational planning for pediatric abdominal surgery. 3D-visualized MRI with volume rendering; Die computerassistierte Operationsplanung in der Abdominalchirurgie des Kindes. 3D-Visualisierung mittels ''volume rendering'' in der MRT

    Energy Technology Data Exchange (ETDEWEB)

    Guenther, P.; Holland-Cunz, S.; Waag, K.L. [Universitaetsklinikum Heidelberg (Germany). Kinderchirurgie; Troeger, J. [Universitaetsklinikum Heidelberg, (Germany). Paediatrische Radiologie; Schenk, J.P. [Universitaetsklinikum Heidelberg, (Germany). Paediatrische Radiologie; Universitaetsklinikum, Paediatrische Radiologie, Heidelberg (Germany)

    2006-08-15

    Exact surgical planning is necessary for complex operations of pathological changes in anatomical structures of the pediatric abdomen. 3D visualization and computer-assisted operational planning based on CT data are being increasingly used for difficult operations in adults. To minimize radiation exposure and for better soft tissue contrast, sonography and MRI are the preferred diagnostic methods in pediatric patients. Because of manifold difficulties 3D visualization of these MRI data has not been realized so far, even though the field of embryonal malformations and tumors could benefit from this. A newly developed and modified raycasting-based powerful 3D volume rendering software (VG Studio Max 1.2) for the planning of pediatric abdominal surgery is presented. With the help of specifically developed algorithms, a useful surgical planning system is demonstrated. Thanks to the easy handling and high-quality visualization with enormous gain of information, the presented system is now an established part of routine surgical planning. (orig.) [German] Komplexe Operationen bei ausgepraegten pathologischen Veraenderungen anatomischer Strukturen des kindlichen Abdomens benoetigen eine exakte Operationsvorbereitung. 3D-Visualisierung und computerassistierte Operationsplanung anhand von CT-Daten finden fuer schwierige chirurgische Eingriffe bei Erwachsenen in zunehmendem Masse Anwendung. Aus strahlenhygienischen Gruenden und bei besserer Weichteildifferenzierung ist jedoch neben der Sonographie die Magnetresonanztomographie (MRT) bei Kindern das Diagnostikum der Wahl. Die 3D-Visualisierung dieser MRT-Daten ist dabei jedoch aufgrund vielfaeltiger Schwierigkeiten bisher nicht durchgefuehrt worden, obwohl sich das Gebiet embryonaler Fehlbildungen und Tumoren geradezu anbietet. Vorgestellt wird eine weiterentwickelte und an die Fragestellungen der abdominellen Kinderchirurgie angepasste, sehr leistungsstarke raycastingbasierte 3D-volume-rendering-Software (VG Studio Max 1

  9. LEXIKALISCHE MITTEL IN DER HOTELWERBUNG

    OpenAIRE

    Blažević, Nevenka

    2003-01-01

    Werbung ist das wichtigste Marketinginstrument in der Hotellerie. Bei jeder Werbekampagne ist die sprachliche Seite von großer Bedeutung. In diesem Beitrag wird die lexikalische Ebene der Prospekttexte analysiert. Es wird auf allgemeine sprachliche Merkmale dieser Textsorte verwiesen. In Hotelprospekten lassen sich zwei Funktionen erkennen: die Informationsfunktion und die Appellfunktion. Die Appellfunktion wird meistens durch Adjektive ausgedrückt. Bei der Auswahl der lexikalischen Mittel...

  10. Magnetic resonance tomography-guided interventional procedure for diagnosis of prostate cancer; MRT-gezielte interventionelle Verfahren zur Abklaerung des Prostatakarzinoms

    Energy Technology Data Exchange (ETDEWEB)

    Schernthaner, M.; Helbich, T.H.; Fueger, B.J.; Memarsadeghi, M.; Stiglbauer, A.; Linhart, H.G.; Doan, A.; Pinker, K.; Brader, P. [Medizinische Universitaet Wien, Univ.-Klinik fuer Radiodiagnostik, Division fuer Molekulare und Gender-Bildgebung, Wien (Austria); Margreiter, M. [Medizinische Universitaet Wien, Univ.-Klinik fuer Urologie, Wien (Austria)

    2011-11-15

    In recent years magnetic resonance imaging (MRI) has been increasingly established in the diagnosis of prostate cancer in addition to transrectal ultrasonography (TRUS). The use of T2-weighted imaging allows an exact delineation of the zonal anatomy of the prostate and its surrounding structures. Other MR imaging tools, such as dynamic contrast-enhanced T1-weighted imaging or diffusion-weighted imaging allow an inference of the biochemical characteristics (multiparametric MRI). Prostate cancer, which could only be diagnosed using MR imaging or lesions suspected as being prostate cancer, which are localized in the anterior aspect of the prostate and were missed with repetitive TRUS biopsy, need to undergo MR guided biopsy. Recent studies have shown a good correlation between MR imaging and histopathology of specimens collected by MR-guided biopsy. Improved lesion targeting is therefore possible with MR-guided biopsy. So far data suggest that MR-guided biopsy of the prostate is a promising alternative diagnostic tool to TRUS-guided biopsy. (orig.) [German] Neben dem transrektalen Ultraschall (TRUS) hat sich in den letzten Jahren die MRT als nichtinvasive Methode zur Bildgebung von Prostatatumoren etabliert. Mittels T2-gewichteter Sequenzen ist eine exakte anatomische Darstellung der Prostata und ihrer umliegenden Strukturen moeglich. Andere MRT-Techniken ermoeglichen Rueckschluesse auf das biologische Verhalten des Tumors: dynamische kontrastmittelverstaerkte T1-gewichtete Sequenzen zur Darstellung der Angiogenese, diffusionsgewichtete Aufnahmen zur Beurteilung der Zelldichte und die Spektroskopie zur Bestimmung von Gewebemetaboliten wie Cholin und Kreatin (multiparametrische Bildgebung). Prostatatumoren, die nur mittels MRT nachweisbar sind oder verdaechtige Tumoren, die hauptsaechlich anterior in der Prostata lokalisiert sind und in wiederholten TRUS-gezielten Biopsien verfehlt wurden, benoetigen eine MRT-gezielte Biopsie zur Diagnosesicherung. Die bisherigen

  11. Magnetic resonance tomography and dental radiology (Dental-MRT); Die Magnetresonanztomographie in der Dentalradiologie (Dental-MRT)

    Energy Technology Data Exchange (ETDEWEB)

    Gahleitner, A. [Wien Univ. (Austria). Abt. fuer Osteologie; Wien Univ. (Austria). Abt. fuer Orale Chirurgie; Solar, P.; Ertl, L. [Wien Univ. (Austria). Abt. fuer Orale Chirurgie; Nasel, C.; Homolka, P. [Wien Univ. (Austria). Inst. fuer Biomedizinische Technik und Physik; Youssefzadeh, S.; Schick, S. [Wien Univ. (Austria). Abt. fuer Osteologie

    1999-12-01

    Purpose: To demonstrate the usefulness of Dental-MRT for imaging of anatomic and pathologic conditions of the mandible and maxilla. Methods: Seven healthy volunteers, 5 patients with pulpitis, 9 patients with dentigerous cysts, 5 patients after tooth transplantation and 12 patients with atrophic mandibles were evaluated. Studies of the jaws using axial T1- and T2-weighted gradient echo and spin echo sequences in 2D and 3D technique have been to performed. The acquired images were reconstructed with a standard dental software package on a workstation as panoramic and cross sectional views of the mandible or maxilla. Results: The entire maxilla and mandibula, teeth, dental pulp and the content of the mandibular canal were well depicted. Patients with inflammatory disease of the pulp chamber demonstrate bone marrow edema in the periapical region. Dentigerous cysts and their relation to the surrounding structures are clearly shown. After contrast media application marked enhancement of the dental pulp can be found. Conclusion: Dental-MRT provides a valuable tool for visualization and detection of dental diseases. (orig.) [German] Ziel dieses Beitrags ist die Vorstellung der Untersuchungsmoeglichkeiten des Ober- und Unterkiefers mittels Magnetresonanztomographie (Dental-MRT) und ihre Anwendung bei der Diagnose zahnmedizinischer Erkrankungen. Sieben gesunde Probanden, 5 Patienten mit Pulpitis, 9 Patienten mit dentogenen Zysten, 5 Patienten nach Zahntransplantationen und 12 Patienten mit atrophem Unterkiefer wurden untersucht. Axiale T1- und T2-gewichtete Gradientenecho- und Spinecho-Sequenzen in 2D und 3D-Technik wurden durchgefuehrt. Nach der Untersuchung wurden zusaetzliche Panoramaschnitte und orhoradiale Rekonstruktionen des Ober- und Unterkiefers, unter Verwendung einer gebraeuchlichen Dental-Software, angefertigt. Der gesamte Ober- oder Unterkiefer, Zaehne, Pulpa und der Inhalt des Mandibularkanals koennen gut dargestellt werden. Patienten mit einer Entzuendung der

  12. Temporomandibular Joint: MRT Diagnostics; Temporomandibulargelenk: MRT-Diagnostik

    Energy Technology Data Exchange (ETDEWEB)

    Kress, B. [Universitaetsklinikum Heidelberg (Germany). Abteilung Neuroradiologie; Universitaetsklinikum Heidelberg (Germany). Neurologische Klinik; Schmitter, M. [Universitaetsklinikum Heidelberg (Germany). Poliklinik fuer zahnaerztliche Prothetik; Universitaetsklinikum Heidelberg (Germany). Abteilung Neuroradiologie

    2005-09-01

    MRI of the temporomandibular joint (TMJ) requires 1.5 T. The radiologist must be familiar with the anatomy and pathology of the TMJ. This review gives a description of MRI protocols for the TMJ, and MRI anatomy and pathology of the TMJ (open and closed mouth) by means of MR images and drawings. Diagnosing of the TMJ related diseases depends on standardized clinical and MR examinations. Therefore close interdisciplinary cooperation between dentist and radiologist is necessary. (orig.) [German] Magnetresonanztomographie bei Kiefergelenkbeschwerden erfordert neben guter technischer Ausstattung Kenntnisse der Anatomie und Pathologie des Kiefergelenks. Diese Uebersicht stellt neben MRT-Protokollen die Anatomie und die pathologischen Befunde des Kiefergelenks bei geoeffnetem und geschlossenem Mund anhand von Abbildungen und Graphiken systematisch dar. Bildgebende Diagnostik des Kiefergelenks gruendet sich auf eine standardisierte klinische und magnetresonanztomographische Untersuchung und erfordert eine enge interdisziplinaere Kooperation zwischen Zahnmedizin und Radiologie. (orig.)

  13. Non-granulomatous prostatitis: MR appearance with an endorectal surface coil; Nichtgranulomatoese Prostatitis: Erscheinungsbild im MRT mit endorektaler Oberflaechenspule (``Endo-MRT``)

    Energy Technology Data Exchange (ETDEWEB)

    Szolar, D.H.M. [Magnetresonanztomographie-Zentrum, Univ. Graz (Austria); Ranner, G. [Magnetresonanztomographie-Zentrum, Univ. Graz (Austria); Preidler, K.W. [Magnetresonanztomographie-Zentrum, Univ. Graz (Austria); Lax, S. [Inst. fuer Pathologische Anatomie, Univ. Graz (Austria)

    1995-01-01

    Inflammatory conditions of the prostate are often idfficult to distinguish from early stages of prostate cancer with imaging techniques. The use of an endorectal surface coil in MRI of the prostate gland has been reported to provide superior resolution and better imaging of details than MRI with a body coil in the diagnosis of early prostate cancer. We report a 34-year-old patient with nonspecific non-granlomatous prostatitis in whom T{sub 2}-weighted endorectal surface coil magnetic resonance imaging (ESCMRI) showed a region of markedly decreased signal intensity in the periphery of the gland. The low signal intensity of the lesion, its sharp demarcation from the normal part of the peripheral zone of the prostate and the marked bulge of the surface contour without capsular breach of the organ were interpreted as evidence of a bioptically proven benign inflammatory condition. (orig.) [Deutsch] Die Unterscheidung entzuendlicher Prozesse von Fruehstadien maligner Neoplasien der Prostata mittels Magnetresonanztomographie bereitet immer wieder Schwierigkeiten. Die Anwendung einer Oberflaechenspule erlaubt durch hoehere Aufloesung eine exaktere Beurteilung der Prostatakapsel, was eine hoehere Treffsicherheit beim Nachweis moeglicher organueberschreitender Infiltrationen bedeutet. Wir praesentieren den Fall eines 34jaehrigen Mannes mit unspezifischer, nichtgranulomatoeser Prostatitis, bei dem das MR-Tomogramm mit endorektal plazierter Oberflaechenspule (Endo-MRT) in der Peripherzone ein Areal deutlich herabgesetzter Signalintensitaet auf T{sub 2}-gewichteten Aufnahmen zeigte. Die scharfe Begrenzung der ausgedehnten signalarmen Laesion gegenueber dem nichtbefallenen Anteil der Peripherzone beim im Endo-MRT identifizierbarer intakter Kapsel liess ein organueberschreitendes Malignom ausschliessen und bestaetigte durch histologische Aufarbeitung der Bioptate den Endo-MRT-Verdachtsbefund einer Prostatitis. (orig.)

  14. Superconducting MRI system, MRT-50A

    International Nuclear Information System (INIS)

    Sugimoto, Hiroshi; Asahina, Kiyotaka

    1987-01-01

    The writers' developmental work on MRI (magnetic resonance imaging) was started in 1983. The model used first was MRT-15A (0.15 T). The next model was MRT-22A (0.22 T) which had a magnetic self-shield. As for the development of superconducting MRI system, they started clinical evaluation at Toshiba Central Hospital MRI Center in 1984 and got the official approval in 1985. For the model, use was made of MRT-50A (0.5 T) employing a superconducting magnet made by Toshiba. Herein represented are the basis of the images obtained through MRT-50 and the fact that the application fields of MRI are going on increasing (not only to brain and spine areas but also to the areas of the chest, abdomen and joints), and also the results of the work-in-progress of application software. (author)

  15. Functional MRT in psychiatry and neurology

    International Nuclear Information System (INIS)

    Schneider, F.; Fink, G.R.

    2007-01-01

    Almost no other method has reach such an interest as the functional imaging in psychiatric and neurological science; it is fascinating to observe the brain at work. The fundamentals of functional magnetic resonance tomography (fMRT) and the interpretation of MRT images are explained; the state-of-the-art is discussed. The book is focussed on the functional imaging within psychiatry and neurology. The book contains 45 contributions within the following chapters: fundamentals, higher brain accomplishments, disease pattern, examinatory examples, perspectives

  16. Functional MR imaging of the patellofemoral joint; Funktionelle MRT des Femoropatellargelenkes

    Energy Technology Data Exchange (ETDEWEB)

    Muhle, C. [Klinik fuer Radiologische Diagnostik, Kiel Univ. (Germany); Brossmann, J. [Klinik fuer Radiologische Diagnostik, Kiel Univ. (Germany); Heller, M. [Klinik fuer Radiologische Diagnostik, Kiel Univ. (Germany)

    1995-02-01

    Conventional X-ray examinations of the patellofemoral joint in 30 , 60 and 90 of knee flexion demonstrate the position of the patella. On the other hand, they have been shown to be insufficient for the diagnosis of patellofemoral maltracking in the critical range between 30 of flexion and full extension. Motion-triggered and ultrafast MRI offer new possibilities for functional diagnosis of the patellofemoral joint under active knee motion. Functional MRI of the patellofemoral joint is suggested as an alternative to arthroscopy, particularly in patients with anterior knee pain or suspected patellar maltracking. (orig.) [Deutsch] Tangentialaufnahmen der Patella in 30 -, 60 - und 90 -Kniebeugung koennen zwar die Lage der Kniescheibe im Femoropatellargelenk darstellen, sie erlauben jedoch keine Aussage ueber die funktionellen Aspekte des Patellagleitens zwischen 30 -Beugung und 0 -Streckung. Dieser fuer die Kniescheibenfuehrung kritische, mittels der konventionellen Roentgentechnik (aufgrund von Femur- und Patellaueberlagerung) nicht einsehbare Bereich, kann unter aktiver Kniestreckung mit der funktionellen MRT dargestellt werden. Durch bewegungsgetriggerte Gradientenechosequenzen oder neuerdings auch durch ultraschnelle Bildsequenzen ist es moeglich, funktionelle Informationen ueber das Patellagleiten in der endgradigen Streckenbewegung zu erhalten. Die funktionelle MRT des Femorpatellargelenkes bietet daher z.B. fuer die Abklaerung von unklaren, vorderen Kniegelenksbeschwerden und bei der Frage nach Patellagleitwegsstoerungen eine Alternative zur diagnostischen Arthroskopie. (orig.)

  17. Magnetic resonance tomography (MRT) in bronchial carcinoma

    International Nuclear Information System (INIS)

    Felix, R.; Bittner, R.; Schoerner, W.; Weiss, T.

    1988-01-01

    Comparative studies were made of 47 patients suffering from histologically and cytologically confirmed bronchial carcinoma, using CT and MRT respectively. CT examinations were performed before and after intravenous administration of contrast medium, whereas the MR examinations were conducted via EEG-triggered T 1 and T 2 marked SE sequences in the axial and coronary planes. Both methods were assessed in respect of tumour visualisation and documentation of tumour spread. Staging of tumour and lymph nodes yielded largely concurring results for CT and MRT. Exceptions were seen in 7 of 10 patients with malignant involvement of the pericardium and in 3 of 27 patients with lymph node metastases located mediastinally and subcarinally where only MRT showed a positive involvement of the pericardium or lymph nodes (with possible consequences for the staging of the tumour or lymph nodes). Decisive advantages of MRT compared with CT were seen in the identification of infiltration of the aortic-wall, in the differentiation of the poststenotic syndrome, in the visualisation of the thoracic wall infiltration and functional information on blood flow rate in upper venolus obstruction caused by a carcinoma. (orig.) [de

  18. Functional MRT in psychiatry and neurology; Funktionelle MRT in Psychiatrie und Neurologie

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, F. [Universitaetsklinikum der RWTH Aachen (Germany). Klinik fuer Psychiatrie und Psychotherapie; Fink, G.R. (eds.) [Koeln Univ. (Germany). Klinik und Poliklinik fuer Neurologie

    2007-07-01

    Almost no other method has reach such an interest as the functional imaging in psychiatric and neurological science; it is fascinating to observe the brain at work. The fundamentals of functional magnetic resonance tomography (fMRT) and the interpretation of MRT images are explained; the state-of-the-art is discussed. The book is focussed on the functional imaging within psychiatry and neurology. The book contains 45 contributions within the following chapters: fundamentals, higher brain accomplishments, disease pattern, examinatory examples, perspectives.

  19. Diffusion-weighted MRI of the prostate; Diffusionsgewichtete MRT der Prostata

    Energy Technology Data Exchange (ETDEWEB)

    Mueller-Lisse, U.G.; Scherr, M.K. [Klinikum der Ludwig-Maximilians-Universitaet Muenchen, Institut fuer Klinische Radiologie, Muenchen (Germany); Mueller-Lisse, U.L. [Klinikum der Ludwig-Maximilians-Universitaet Muenchen, Klinik und Poliklinik fuer Urologie, Muenchen (Germany); Zamecnik, P.; Schlemmer, H.P.W. [Deutsches Krebsforschungszentrum (DKFZ), Abteilung fuer Radiologische Diagnostik, Heidelberg (Germany)

    2011-03-15

    Prostatagewebe in der peripheren Zone und Prostatakarzinom sind fuer den ADC im Mittel offenbar geringer als fuer das (Cholin + Kreatin)/Zitrat-Verhaeltnis bei der MR-Spektroskopie. Die Testgueteparameter liegen etwas besser fuer MRT mit DWI als fuer MRT der Prostata allein, zeigen aber deutliche Unterschiede zwischen verschiedenen Studien. Die klinische Bewertung der DWI der Prostata erfordert verfahrenstechnische Vereinheitlichungen und Studien mit hohen Patientenzahlen. (orig.)

  20. Magnetic resonance tomography (MRT) for lesions of the temporal lobes

    International Nuclear Information System (INIS)

    Schoerner, W.; Felix, R.; Meencke, H.J.; Freie Univ. Berlin; Freie Univ. Berlin

    1985-01-01

    A comparative study between magnetic resonance tomography (MRT) and CT was carried out in 16 patients with temporal lobe epilepsy. The MRT studies were performed on a 0.35 T Magnetom with T.1 modes in a coronal plane. MRT proved to the superior to CT. CT demonstrated a discrete temporal lobe lesion in three patients and MRT in four patients. In addition, unilateral atrophy of the temporal lobe was demonstrated by MRT in six cases; these could not be diagnosed by CT. The lack of artifacts near the skull base, the possibility of producing coronal sections and the excellent tissue differential of MRT provide the basis for improved diagnosis of lesions in the temporal lobes. (orig.) [de

  1. MR-based diagnosis and staging of female pelvic neoplasms; Diagnostik und Staging gynaekologischer Tumoren mittels MRT

    Energy Technology Data Exchange (ETDEWEB)

    Alt, Celine D. [Universitaetsklinik Duesseldorf (Germany). Inst. fuer Diagnostische und Interventionelle Radiologie; Kubik-Huch, Rahel A. [Zuerich Univ. (Switzerland). Diagnostische Radiologie; Kantonsspital Baden AG (Switzerland). Dept. Medizinische Dienste

    2017-06-15

    Magnetic resonance imaging (MRI) is known as the cross-sectional imaging modality of choice for evaluation of the female pelvis due to an excellent soft tissue contrast and its high resolution images. It provides morphologic and functional sequences and is commonly used for evaluation of a sonographically indeterminate adnexal mass, for differentiation and characterization of pelvic organ lesions, as well as for tumor staging and therapy monitoring during/after treatment. This article gives insights into the currently valid implementation of MR-imaging, tailored to the different female pelvic organs and its special features.

  2. Grading sacroiliitis with emphasis on MRI imaging; Grading der Sakroiliitis mit Betonung der MRT-Bildgebung

    Energy Technology Data Exchange (ETDEWEB)

    Jurik, A.G.; Egund, N. [The Department of Radiology R, Aarhus Kommunehospital (Denmark)

    2004-03-01

    Cross-sectional imaging techniques play a decisive role in identification, localization, and characterization of alterations in the sacroiliac joint during the early stage of seronegative spondylarthropathy (SpA). Although several studies showed that the diagnostic capabilities of MRI and CT are superior to those of conventional radiography, they have not yet become established and accepted as methods for evaluating the grade of ankylosing spondylitis (AS) in contrast to conventional radiography. The lack of acceptance for MRI and/or CT methods for evaluating and grading changes in the sacroiliac joint makes it difficult to include the results of these procedures in classifying the grade of SpA. Moreover, grading the changes in the sacroiliac joint in SpA with a method more sensitive than conventional radiography will be of prime importance in assessing treatment, e.g., the efficacy of new biological therapeutic agents directed against the tumor necrosis factor-alpha (TNF-{alpha}). An overview of the available grading methods is provided and MRI and CT techniques are presented. (orig.) [German] Schnittbildverfahren spielen bei der Identifizierung, Lokalisation und Charakterisierung von Veraenderungen des Sakroiliakalgelenks (SIG) im Fruehstadium der seronegativen Spondylarthropathie (SpA) eine entscheidende Rolle. Obwohl mehrere Studien zeigten, dass der diagnostische Wert der MRT und CT jenem der konventionellen Radiographie ueberlegen ist, hat sich das Schnittbildverfahren als Mittel zur Evaluierung des Grades der ankylosierenden Spondylitis (AS) im Gegensatz zur konventionellen Radiographie noch nicht etabliert und durchgesetzt. Dieses Fehlen eines akzeptierten MRT- und/oder CT-Verfahrens zur Evaluierung und zum Grading der Veraenderungen am SIG macht es schwierig, die Ergebnisse dieser Verfahren bei der Einstufung des Grades der AS-Veraenderungen und Erarbeitung von Diagnosekriterien fuer andere Formen der SpA einzubeziehen. Ausserdem wird das Grading der SIG

  3. Fetal MRI of pathological brain development; Fetale MRT der pathologischen Hirnentwicklung

    Energy Technology Data Exchange (ETDEWEB)

    Brugger, P.C. [Medizinische Universitaet Wien (Austria). Arbeitsgruppe Integrative Morphologie, Zentrum fuer Anatomie und Zellbiologie; Prayer, D. [Medizinische Universitaet Wien (Austria). Klinik fuer Radiodiagnostik

    2006-02-15

    Because of the superior tissue contrast, high spatial resolution, and multiplanar capabilities, fetal magnetic resonance imaging (MRI) can depict fetal brain pathologies with high accuracy. Pathological fetal brain development may result from malformations or acquired conditions. Differentiation of these etiologies is important with respect to managing the actual pregnancy or counseling future pregnancies. As a widened ventricular system is a common hallmark of both maldevelopment and acquired conditions, it may cause problems in the differential diagnosis. Fetal MRI can provide detailed morphological information, which allows refinement of the diagnosis of ventricular enlargement in a large number of cases. Systematic work-up of morphological details that may be recognized on MR images provides an approach for achieving a correct diagnosis in cases of ventricle enlargement. (orig.) [German] Aufgrund des hervorragenden Gewebekontrastes, der hohen raeumlichen Aufloesung und multiplanaren Moeglichkeiten erlaubt die fetale Magnetresonanztomographie (MRT) eine detaillierte Darstellung fetaler Hirnpathologien. Eine pathologische Hirnentwicklung kann sowohl auf Fehlbildungen als auch waehrend der Schwangerschaft erworbenen Stoerungen beruhen. Nachdem die weiteren Konsequenzen fuer die bestehende, aber auch fuer folgende Schwangerschaften zu einem grossen Teil von einer Differenzierung dieser Aetiologien abhaengig sein kann, ist ein Erkennen der jeweiligen Pathologie wesentlich. Die morphologische Praesentation erworbener und fehlbildungsbedingter Veraenderungen auf MR-Bildern ist u. U. sehr aehnlich. Besondere differenzialdiagnostische Probleme bereitet dabei das Vorliegen eines erweiterten Ventrikelsystems, das als Symptom unterschiedlichster Veraenderungen vorliegen kann. Anhand einer systematischen Darstellung mittels MR-erfassbarer morphologischer Details wird eine Anleitung gegeben, bei Bestehen dieses Leitsymptoms zu einer moeglichst genauen Diagnose zu kommen

  4. MRT of the locomotor system. 4. rev. and enl. ed.; MRT des Bewegungsapparats

    Energy Technology Data Exchange (ETDEWEB)

    Vahlensieck, Martin [Praxisnetz Radiologie und Nuklearmedizin Bonn Bad Godesberg - RheinSieg, Bonn (Germany); Reiser, Maximilian (ed.) [Klinikum Grosshadern, Muenchen (Germany). Inst. fuer Klinische Radiologie

    2015-02-01

    The book on MRT of the locomotor system covers the following topics: relevant NMT imaging techniques, spinal cord, shoulder, elbows, wrist and fingers, hip region, knee, lower leg - ankle - foot, temporomandibular joint, skeletal muscles, bone marrow, bone and soft tissue tumors, osteoporosis, sacroiliac joint, jaw and periodontium.

  5. MRI for myocarditis; MRT bei Myokarditis

    Energy Technology Data Exchange (ETDEWEB)

    Gutberlet, M.; Luecke, C.; Krieghoff, C.; Hildebrand, L.; Steiner, J.; Adam, J.; Grotthoff, M.; Lehmkuhl, L. [Herzzentrum, Universitaet Leipzig, Abteilung fuer Diagnostische und Interventionelle Radiologie, Leipzig (Germany); Lurz, P.; Eitel, I.; Thiele, H. [Herzzentrum, Universitaet Leipzig, Abteilung Kardiologie, Leipzig (Germany)

    2013-01-15

    Cardiovascular magnetic resonance imaging (CMRI) has become the primary tool for the non-invasive assessment in patients with suspected myocarditis, especially after exclusion of acute coronary syndrome (ACS) for the differential diagnosis. Various MRI parameters are available which have different accuracies. Volumetric and functional ventricular assessment and the occurrence of pericardial effusion alone demonstrate only a poor sensitivity and specificity. The calculation of the T2-ratio (edema assessment), the early or global relative myocardial enhancement (gRE) and the late gadolinium enhancement (LGE), which represents irreversibly injured myocardium, are more specific parameters. All MRI parameters demonstrate the best accuracy in infarct-like acute myocarditis, whereas in chronic myocarditis sensitivity and specificity are less accurate. Therefore, a multisequential (at least two out of three parameters are positive) approach is recommended. The assessment of the value of newer, more quantitative MRI sequences, such as T1 and T2-mapping is still under investigation. (orig.) [German] Die kardiale MRT stellt die primaere nichtinvasive bildgebende Modalitaet bei Verdacht auf Myokarditis dar, insbesondere auch nach Ausschluss eines akuten Koronarsyndroms (ACS) zur Differenzialdiagnose. Verschiedene MR-Parameter mit unterschiedlicher Wertigkeit stehen zur Verfuegung. Die Beurteilung der Volumetrie und Ventrikelfunktion weisen ebenso wie der Nachweis eines Perikardergusses alleine nur eine geringe Sensitivitaet und Spezifitaet auf. Die spezifischeren MRT-Inflammationsparameter stellen die T2-Ratio (Oedemnachweis), die fruehe Kontrastmittelanreicherung bzw. das globale relative Enhancement (gRE) und die spaete Kontrastmittelanreicherung, das so genannte Late-Gadolinium-Enhancement (LGE) als Zeichen eines irreversiblen Myokardschadens dar. Alle MR-Parameter zeigen die beste diagnostische Genauigkeit bei einer ''infarktaehnlichen'' akuten

  6. MRT of scaphoid pseudo-arthrosis using Gd-DTPA. Staging and clinical correlation; MRT der Skaphoidpseudarthrose mit Gd-DTPA. Stadieneinteilung und klinische Korrelation

    Energy Technology Data Exchange (ETDEWEB)

    Vogl, T.J. [Freie Univ. Berlin (Germany). Strahlenklinik und Poliklinik; Beutel, F. [Freie Univ. Berlin (Germany). Strahlenklinik und Poliklinik; Wilhelm, K. [LMU Muenchen (Germany). Abt. fuer Handchirurgie; Tempka, A. [Freie Univ. Berlin (Germany). Klinik fuer Unfall- und Wiederherstellungschirurgie; Schedel, H. [Freie Univ. Berlin (Germany). Strahlenklinik und Poliklinik; Haas, R. [Freie Univ. Berlin (Germany). Strahlenklinik und Poliklinik; Felix, R. [Freie Univ. Berlin (Germany). Strahlenklinik und Poliklinik

    1994-11-01

    During a period of two years, 134 patients with pseudo-arthrosis of the scaphoid were examined by conventional radiography and by MRI in the course of a prospective study. The aim of the study was to define radiological staging using contrast enhanced MRI in order to improve the prognostic criteria. All MRI examinations were carried out with a 1.5 Tesla scanner (SP63) using a surface coil and T{sub 1} weighted spin echo sequences in sagittal and frontal projection and frontal FLASH T{sub 2}-sequences and axial spin echo T{sub 2} sequences. The T{sub 1} weighted SE sequences in frontal projection were carried out before and after iv contrast (0.1 mmol Gd-DTPA/kg KG). All sequences were compared with conventional radiographs and the operative findings. Eight patients in stage 0 showed high signal intensity of both fragments in T{sub 1} weighted SE sequences and at surgery there was good vascularisation. In 22 cases there was reduced signal intensity in at least one fragment (stage I). 45 patients with scaphoid pseudo-arthrosis showed complete signal loss but marked contrast uptake with still vital nuclei at surgery (stage II). In 22 patients, there was no increase in signal intensity after contrast and complete loss of vitality of the fragments at surgery. Staging was not possible in 37 patients because of previous operative intervention. The use of contrast enhanced MRI provides additional information compared with conventional radiography or plain MRI. (orig.) [Deutsch] Im Rahmen einer prospektiven Studie wurden in einem Zeitraum von 2 Jahren 134 Patienten mit einer Skaphoidpseudarthrose (SPA) vergleichend konventionell roentgenologisch und magnetresonanztomographisch untersucht. Ziel der Studie war die Erstellung einer klinisch radiologischen Stadieneinteilung mit Hilfe der kontrastverstaerkten MRT zur Verbesserung von Prognosekriterien. Alle MRT-Untersuchungen wurden an einem 1,5 Tesla-Geraet (SP63) mittels einer Oberflaechenspule unter Verwendung von T{sub 1

  7. Neurofunctional MRI at high magnetic fields; Neurofunktionelle MRT bei hohen Feldern

    Energy Technology Data Exchange (ETDEWEB)

    Speck, O. [Fakultaet fuer Naturwissenschaften, Otto-von-Guericke Universitaet Magdeburg, Abteilung Biomedizinische Magnetresonanz, Institut fuer Experimentelle Physik, Magdeburg (Germany); Leibniz Institut fuer Neurobiologie, Magdeburg (Germany); Deutsches Zentrum fuer Neurodegenerative Erkrankungen (DZNE), Magdeburg (Germany); Center for Behavioral Brain Sciences (CBBS), Magdeburg (Germany); Turner, R. [MPI fuer Kognitions- und Neurowissenschaften, Abteilung Neurophysik, Leipzig (Germany)

    2013-05-15

    group data without the need for voxel-based congruence. (orig.) [German] fMRT-Untersuchungen sind durch den geringen aktivierungsinduzierten Signalunterschied in ihrer Sensitivitaet limitiert und innerhalb kurzer tolerierbarer Messzeiten ist die raeumliche Aufloesung limitiert. fMRT bei 1,5 und mehr noch bei 3 T ist ein zuverlaessiges Werkzeug in der Neurowissenschaft und fuer klinische Anwendungen, wie etwa die praechirurgische Funktionslokalisierung. Die fMRT-Sensitivitaet steigt stark (mehr als linear) mit hoeherer Magnetfeldstaerke. Dies war seit Jahren einer der Hauptgruende fuer die Entwicklung zu hoeheren Feldern wie etwa 7 T. Der Sensitivitaetsgewinn von 7 gegenueber 3 T ist bei hoher raeumlicher Aufloesung am groessten und die fMRT mit sehr hoher isotroper Submillimeteraufloesung wird moeglich. Bisherige Resultate zeigen, dass die Blood-oxygenation-level-dependent(BOLD)-Lokalisierung deutlich praeziser ist als bislang angenommen. Mittels Hochfeld-fMRT werden nicht nur quantitativ bessere Ergebnisse erzielt, sondern Informationen neuer Qualitaet zugaenglich wie etwa die kolumnare und schichtabhaengige Struktur des Kortex. Somit wird der Weg zu weiteren Informationen, wie etwa die Richtung kortikaler Verbindungen, eroeffnet. Diese Moeglichkeiten bergen jedoch auch neue Herausforderungen. So muessen neue Verfahren zur Prozessierung derart hochaufgeloester Daten entwickelt werden, welche z. B. ohne Glaettung auskommen, um den Informationsgehalt der Daten nicht zu reduzieren. Standardaufloesungen von 2-3 mm sind weiterhin bei 3 T ''gut aufgehoben'' und profitieren von geringeren Signalausloeschungen, weniger Verzerrungen und geringerer Lautstaerke. Zum Erreichen hoechster Aufloesung bei 7 T sind parallele Bildgebung und Verzerrungskorrektur essenziell und ermoeglichen eine gute Uebereinstimmung mit anatomischen Aufnahmen. Die Echozeit sollte bei 7 T auf ca. 20-25 ms angepasst und die Datenauswertung fuer einzelne Probanden oder Patienten ohne

  8. MRT of the central nervous system. 2. rev. and enl. ed.; MRT des Zentralnervensystems

    Energy Technology Data Exchange (ETDEWEB)

    Forsting, Michael [Universitaetsklinikum Essen (Germany). Inst. fuer Diagnostische und Interventionelle Radiologie und Neuroradiologie; Jansen, Olav (ed.) [Universitaetsklinikum Schleswig-Holstein, Kiel (Germany). Klinik fuer Radiologie und Neuroradiologie

    2014-11-01

    The book on MRT of the central nervous system includes the following chapters: anatomy, vascular diseases, brain tumors, craniocerebral injuries, infectious diseases, multiple sclerosis and related diseases, metabolic diseases, degenerative diseases, malformations and developmental disorders, hydrocephalus and intracranial hypertension, spinal marrow, degenerative caused spinal and foraminal stenosis, traumata, tumors and tumor-like neoplasm, vascular diseases, inflammations, infections and related diseases, diseases of the peripheral nervous system.

  9. MRI for therapy control in patients with aortic isthmus stenosis; MRT zur Therapiekontrolle bei Patienten mit Aortenisthmusstenose

    Energy Technology Data Exchange (ETDEWEB)

    Wintersperger, B.J. [Klinikum der Ludwig-Maximilians-Universitaet Muenchen, Campus Grosshadern, Institut fuer Klinische Radiologie, Muenchen (Germany); Toronto General Hospital, University of Toronto, Department of Medical Imaging, University Health Network, Toronto M5G 2N2 (Canada); Theisen, D.; Reiser, M.F. [Klinikum der Ludwig-Maximilians-Universitaet Muenchen, Campus Grosshadern, Institut fuer Klinische Radiologie, Muenchen (Germany)

    2011-01-15

    Aortic isthmus stenosis is the most common congenital aortic anomaly and is often a problem for therapy surveillance. In addition to possible comorbidities (e.g. bicuspid aortic valve) it is accompanied by various middle and long-term complications depending on the primary choice of the therapeutic procedure. Magnetic resonance imaging (MRI) plays an important role for the mostly young patients in the control of the aortic isthmus stenosis and therapy because it is non-invasive and there is no X-ray exposure. Radiologists should be well-informed on the principles of the therapeutic procedure in order to be competent in the interpretation of MRI findings. Due to the continuous development of MRI technology, techniques for functional evaluation (e.g. dynamic MRA, 4D PC flow measurement) are increasingly becoming available in addition to high-resolution MR angiography (MRA), which could predict the risk of possible complications, such as aneurysms. However, in this aspect further studies are necessary. Interventional therapy with stents and stent grafts is often employed for the therapy of possible complications following an operation (aneurysms, restenosis) but because of massive metal artefacts the use of MRI is often sometimes severely limited. (orig.) [German] Die Aortenisthmusstenose als haeufigste angeborene Aortenanomalie stellt ein haeufiges Problem der Therapieueberwachung dar und ist neben moeglichen begleitenden Anomalien (z. B. bikuspidale Aortenklappe) in Abhaengigkeit vom primaer gewaehlten Therapieverfahren mit verschiedenen Komplikationen im mittel- bis laengerfristigem Verlauf vergesellschaftet. Bei der Kontrolle der Aortenisthmusstenose bzw. deren Therapie spielt die Magnetresonanztomographie (MRT) aufgrund der Nichtinvasivitaet und fehlenden Strahlenexposition bei den meist juengeren Patienten eine wichtige Rolle. Der Radiologe sollte ueber die Grundzuege der Therapieverfahren informiert sein, um die MRT-Befunde kompetent zu befunden. Durch stetige

  10. MRI of pulmonary perfusion; MRT der Lungenperfusion

    Energy Technology Data Exchange (ETDEWEB)

    Fink, C. [Klinikum Grosshadern der Ludwig-Maximilians-Universitaet Muenchen (Germany). Institut fuer Klinische Radiologie; Deutsches Krebsforschungszentrum (DKFZ), Abteilung Radiologie, Heidelberg (Germany); Risse, F.; Semmler, W. [Deutsches Krebsforschungszentrum (DKFZ), Abteilung Medizinische Physik in der Radiologie, Heidelberg (Germany); Schoenberg, S.O.; Reiser, M.F. [Klinikum Grosshadern der Ludwig-Maximilians-Universitaet Muenchen (Germany). Institut fuer Klinische Radiologie; Kauczor, H.-U. [Deutsches Krebsforschungszentrum (DKFZ), Abteilung Radiologie, Heidelberg (Germany)

    2006-04-15

    Lung perfusion is a crucial prerequisite for effective gas exchange. Quantification of pulmonary perfusion is important for diagnostic considerations and treatment planning in various diseases of the lungs. Besides disorders of pulmonary vessels such as acute pulmonary embolism and pulmonary hypertension, these also include diseases of the respiratory tract and lung tissue as well as pulmonary tumors. This contribution presents the possibilities and technical requirements of MRI for diagnostic work-up of pulmonary perfusion. (orig.) [German] Die Perfusion der Lunge ist eine entscheidende Voraussetzung fuer einen effektiven Gasaustausch. Die Bestimmung der Lungenperfusion ist bei verschiedenen Erkrankungen der Lunge fuer Diagnostik und Therapieplanung bedeutsam. Hierzu zaehlen neben Erkrankungen der Lungengefaesse wie akute Lungenembolie und pulmonale Hypertension ebenso Erkrankungen der Atemwege, des Lungengeruests und Lungentumoren. In diesem Beitrag werden die Moeglichkeiten und technischen Voraussetzungen der MRT zur Diagnostik der Lungenperfusion dargestellt. (orig.)

  11. Clinical use of MR imaging-guided interventions; Klinischer Einsatz der interventionellen MRT (iMRT)

    Energy Technology Data Exchange (ETDEWEB)

    Kahn, T.; Schulz, T.; Moche, M.; Prothmann, S.; Schneider, J.P. [Klinik und Poliklinik fuer Diagnostische Radiologie, Univ. Leipzig (Germany)

    2003-07-01

    The integration of diagnostic and therapeutic procedures by MRI is based on the combination of excellent morphologic and functional imaging. The spectrum of MR-guided interventions includes biopsies, thermal ablation procedures, vascular applications, and intraoperative MRI. In all these applications, different scientific groups have obtained convincing results in basic developments as well as in clinical use. Interventional MRI (iMRI) is expected to attain an important role in interventional radiology, minimal invasive therapy, and monitoring of surgical procedures. (orig.) [German] Die Integration diagnostischer und therapeutischer Massnahmen durch die MRT basiert auf der Kombination von exzellenter morphologischer und funktioneller Bildgebung. Das Spektrum MR-gefuehrter Eingriffe reicht von Biopsien, thermischen Therapieverfahren, vaskulaeren Applikationen bis hin zum intraoperativen Einsatz der MRT. Auf allen Gebieten konnten von verschiedenen Arbeitsgruppen ueberzeugende Ergebnisse sowohl im Bereich der Grundlagenentwicklung als auch bei klinischen Anwendungen vorgelegt werden. Es ist davon auszugehen, dass die interventionelle MRT einen hohen Stellenwert im Bereich der interventionellen Radiologie, der minimal-invasiven Therapie und der Ueberwachung von operativen Eingriffen erlangen wird. (orig.)

  12. Preoperative assessment of asymptomatic adnexal masses by positron emission tomography and F-18-fluorodeoxyglucose; Praeoperative Dignitaetsbeurteilung asymptomatischer Adnextumoren mittels Positronen-Emissions-Tomographie und F-18-Fluordeoxyglukose

    Energy Technology Data Exchange (ETDEWEB)

    Fenchel, S.; Kotzerke, J.; Reske, S.N. [Ulm Univ. (Germany). Abt. Nuklearmedizin; Stoehr, I.; Grab, D.; Kreienberg, R. [Ulm Univ. (Germany). Frauenklinik; Nuessle, K.; Rieber, A.; Brambs, H.J. [Ulm Univ. (Germany). Abt. Radiologie 1 (Roentgendiagnostik)

    1999-08-01

    Aim: To evaluate use of F-18-FDG-PET in assessment of dignity of asymptomatic adnexal masses. Methods: 85 asymptomatic patients with suspicious, asymptomatic adnexal masses were evaluated. Static FDG-PET (Exact HR+ or ECAT 931) imaging of the abdomen was performed following application of 222-555 MBq F-18-FDG. Iterative reconstruction was applied. PET data were analysed visually, at first without and second together with MRT images. Final diagnosis was made by histopathology. Results: FDG-PET allowed correct identification of 4 of 8 malignant adnexal tumors. False negative results were obtained in 2 adenocarcinomas stage pT1a and 2 borderline-tumors. In 60 out of 77 benign adnexal masses malignancy could be excluded. False positive FDG-uptake, partly because of misinterpretation of gastrointestinal activity, was found in 3 inflammatory processes, 1 teratoma, 1 benign schwannoma, 1 dermoid cyst, 1 benign thecoma, 1 serous cyst, 1 serous cystadenoma, 2 mucinous cystadenomas, 2 corpus luteum cysts, 3 endometriosic cysts and 1 sactosalpinx. The overall sensitivity and specifity of FDG-PET alone were 50% and 78%. Evaluation together with MRT images showed a sensitivity of 50% and a specifity of 86%. (orig.) [Deutsch] Ziel: Es wurde untersucht, ob die FDG-PET zu einer Verbesserung der Dignitaetsbeurteilung asymptomatischer, sonographisch malignomsuspekter Ovarialtumoren beitragen kann. Methode: 85 Patientinnen mit malignomsuspekten, asymptomatischen Adnextumoren unterzogen sich einer FDG-PET Untersuchung. Emissionsaufnahmen des Abdomens wurden ca. 1 h nach i.v. Injektion von 222-555 MBq F-18-FDG angefertigt (Exact HR + bzw. ECAT 931). Die Bildrekonstruktion erfolgte iterativ. Die PET-Aufnahmen wurden visuell ausgewertet, zum einen ohne andere bildgebende Verfahren, zum anderen zusammen mit der Kernspintomographie. Die Validierung erfolgte mittels Histologie. Ergebnisse: Histologisch fanden sich 8 Malignome, von denen 4 mittels FDG-PET als richtig positiv erkannt wurden

  13. Diagnosis of tumors in the shoulder girdle by means of MRI; Diagnostik von Tumoren des Schulterguertelbereichs in der MRT

    Energy Technology Data Exchange (ETDEWEB)

    Schlecht, I.; Gaffke, G.; Stroszczynski, C.; Felix, R. [Charite Campus Virchow-Klinikum, Berlin (Germany). Strahlenklinik und Poliklinik

    2001-07-01

    The aim of the study was to estimate the value of MRI for evaluation of tumors of the shoulder girdle. We diagnosed respectively 13 patients with lesions in the shoulder region. The imaging has been done with a 'Magnetom SP 63' (Siemens, Erlangen, Germany). The protocol consisted of T1- and T2-based SE-sequences in axial slice orientation, T1-based imaging in coronary respectively in sagittal slice orientation as well as T1-based sequences after application of contrast medium. The evaluation of the tumor expansion within the soft tissue was possible. The exact diagnosis in some individual cases - neurinoma, cyst of the synovia - could be found by MRI. Estimation of the dignity in the case of infiltrative growth was possible in most cases. To assess the exact type of tumor was often difficult. Especially the dignity of the cartilaginous tumors could not be precisely described. (orig.) [German] Ziel der Arbeit war es, den Stellenwert der MRT zur Beurteilung von Raumforderungen im Schulterguertelbereich zu evaluieren. Wir konnten retrospektiv 13 Patienten mit Laesionen in der Schulterregion evaluieren. Die Untersuchungen erfolgten an einem 1,5 T supraleitenden Magneten ('Magnetom SP 63', Firma Siemens, Erlangen Deutschland). Das Untersuchungsprotokoll umfasste T1- und T2-gewichtete SE-Sequenzen in axialer Schnittfuehrung und T1-gewichtete Aufnahmen in schraeg koronarer bzw. schraeg sagittaler Schnittfuehrung sowie T1-gewichtete Sequenzen nach Kontrastmittelgabe. Die Beurteilung der Tumorausdehnung in die Weichteile ist mittels der MRT moeglich. Eine Diagnose ist in Einzelfaellen - Neurinom und Synovialzyste - erst mit der Kernspintomographie sicher zu stellen. Ein infiltratives Wachstum laesst sich in der Regel nachweisen, eine Artdiagnose ist jedoch haeufig nicht moeglich. Die Dignitaet konnte insbesondere bei cartilaginaeren Tumoren nicht eindeutig festgelegt werden. (orig.)

  14. Untersuchungen zur Rauchgasentstickung mittels Schwefelwasserstoff in Tri-n-butylphosphat

    OpenAIRE

    Homann, Jörg

    2000-01-01

    In der vorliegenden Arbeit wurde die Reaktion von Stickstoffmonoxid (NO) mit Schwefelwassersoff (H2S) in Tri-n-butylphosphat (TBP) im Hinblick auf ein alternatives Verfahren zur Entstickung von Rauchgasen untersucht. Mittels einer gasvolumetrischen Absorptionsapparatur wurden zuerst Daten zur physikalischen Löslichkeit in TBP ermittelt, die für den Erhalt kinetischer Daten der stofftransportüberlagerten Reaktionen in TBP relevant sind. Es sind dies die Henrykoeffizienten von NO, H2S und die d...

  15. The diagnostic use of MRT in cases of suspected spondylitis; MRT-Differentialdiagnose bei Verdacht auf Spondylitis

    Energy Technology Data Exchange (ETDEWEB)

    Lehner, K. [Inst. fuer Roentgendiagnostik, Klinikum rechts der Isar der Technischen Univ. Muenchen (Germany)

    1994-11-01

    In cases where MRT fails to reveal abscess formation or typical vertebral changes to confirm the preliminary diagnosis, further examinations are necessary to exclude diseases other than spondylitis. More remote possibilities like insufficiency fracture, rheumatic disorders and neoplasm can mostly be ruled out on the basis of conventional X-ray pictures. Conventional tomography and computed tomography should also be carried out in addition to MRT in the rare case of unconfirmed activated arthrosis or disc removal syndrome. In order to distinguish between infective and non-infective/reactive changes, contrast-enhanced repeat MRT following antibiotic treatment may be very helpful. (orig.) [Deutsch] Wenn bei einer Spondylitis ein dafuer beweisender Abszess oder eine typische Destruktion des Wirbelkoerpers nicht vorliegt, ist auch nach Durchfuehrung einer MRT oft eine differentialdiagnostische Abgrenzung gegenueber anderen Ursachen erforderlich. Ferner stehende Differentialdiagnosen wie Insuffizienzfraktur, rheumatische Erkrankungen und eine Neoplasie koennen mit den Moeglichkeiten des konventionellen Roentgenbildes meist ausgeschlossen werden. An die konventionelle- und Computertomographie sollte - auch nach Durchfuehrung der MRT - noch in unklaren Einzelfaellen von aktivierter Arthrose oder Postdisketomie-Syndrom gedacht werden. Eine gute differentialdiagnostische Moeglichkeit zur Unterscheidung zwischen einem Infekt und einem nicht infektioesen/reaktivem Geschehen ist die Wiederholungs-MRT mit KM-Applikation nach durchgefuehrter antibiotischer Behandlung. (orig.)

  16. Early alterations in the hip joint following epiphysiolysis for slipped femoral head. Results of an MRI study; Fruehveraenderugen im Hueftgelenk nach Epiphysiolysis capitis femoris. MRT-Untersuchungsergebnisse

    Energy Technology Data Exchange (ETDEWEB)

    Stoever, B. [Freiburg Univ. (Germany). Radiologische Klinik; Sigmund, G. [Freiburg Univ. (Germany). Radiologische Klinik; Huhle, P. [Freiburg Univ. (Germany). Orthopaedische Abteilung; Zwack, P. [Freiburg Univ. (Germany). Orthopaedische Abteilung; Reichert, A. [Freiburg Univ. (Germany). Orthopaedische Abteilung; Langer, M. [Freiburg Univ. (Germany). Radiologische Klinik

    1994-01-01

    With the aim of detecting patients at risk of developing coxarthritis, 34 patients were investigated prospectively by MRI 6-14 years after epiphysiolysis for slipped capital femoral head. In particular, cartilage changes were analysed by gradient-echo sequences. In 40% of the hip joints investigated cartilaginous lesions were present, detectable as irregularity and flattening of contour and more rarely as changes in signal intensity. In contrast, only 18% of the radiographs available revealed any pathology. When pelvic X-rays are normal or reveal slight sclerosis, cartilaginous lesions on MRI are considered early signs of coxarthrosis. This combination was seen especially often in patients with a primarily high angle of dislocation and in those who needed treatment by reposition or osteotomy. Only in 8 of the 17 hip joints showing sclerosis on conventional radiograms, sclerosis was also diagnosed by MRI, possibly because of partial volume and susceptibility effects at high field strength. Even with limited spatial resolution, cartilage examinations is warranted in young patients in whom early osteoarthritis can be expected. (orig.) [Deutsch] Mit dem Ziel, Veraenderungen am Hueftgelenk bei Patienten mit Arthroserisiko rechtzeitig zu erfassen, wurden 34 Patienten 6-14 Jahre nach einer Epiphysiolysis capitis femoris mittels MRT im Hochfeld bei 2/T nachuntersucht. Insbesondere sollten anhand der `FLASH`-Gradientenechosequenzen Knorpelveraenderungen analysiert werden. In 40% der untersuchten Hueftgelenke lagen Knorpellaesionen vor, sichtbar als Verduennung der Knorpelschicht, Konturunregelmaessigkeit und seltener als Signalintensitaetsveraenderungen. Dagegen waren nur 18% der vorhandenen Roentgenbefunde eindeutig pathologisch. Die kernspintomographisch sichtbaren Laesionen des Knorpels sind bei normalem Roentgenbild als Fruehveraenderungen zu werten und waren haeufiger bei Patienten mit primaer hohem Dislokationswinkel nachweisbar wie auch bei Patienten, bei denen eine

  17. Differentiation of testicular diseases via dynamic MRT

    International Nuclear Information System (INIS)

    Kaiser, W.A.; Reinges, T.; Miersch, W.D.; Vogel, J.

    1994-01-01

    The present study aimed at resolving whether dynamic MRT can improve diagnostic relevance in diseases of the testes compared with conventional spin echo images. The testes of 20 healthy volunteers and of 16 patients of the Department of Urology of the University of Bonn were examined by means of MR tomography. Within 12 hours after MR tomography the patients were surgically explored, biopsied and if necessary orchiectomised. Results obtained with the volunteers were uniform and well reproducible, independent of external influences. On comparing the maximal enhancement curves of the examined various testicular tumors with the standard values established by examining the healthy volunteers, the curves obtained with the malignant testicular tumors were always clearly above the chosen confidence range of 3 standard deviations so that malignancy diagnosis was easy. However, the degree of maximal enhancement did not enable us to arrive at a conclusion in respect of the tumor type or the degree of malignancy. The greatest enhancement occurred with the tumor of Sertoli's cell which could thus be clearly differentiated against the other malignant testicular tumors. Due to masking of the gadolinium effect by haemosiderin deposits, haemorrhagica in the tumor tissue should be excluded by means of T 2 -weighted spin echo sequences before following up a suspicion of malignant testicular tomor. Benign intratesticular changes could be safely separated from malignant findings by means of the maximal enhancement curve lying in the normal range or below the curve of the volunteers. As with other organs, dynamic MR tomography yields definitely more and better information than conventional MR tomography also in the diagnosis of testicular tumours. However, these ''pros'' do not offset the ''cons'' of high costs of such examinations. (orig.) [de

  18. Magnetic resonance imaging (MRI) of the TMJ: Influence on therapy and inter-observer agreement of two radiologists; Magnetresonanztomographie (MRT) des Kiefergelenkes: Einfluss auf Therapieentscheidung und Uebereinstimmung zweier Auswerter

    Energy Technology Data Exchange (ETDEWEB)

    Vahlensieck, M.; Okweschokwu, S. [Radiologie Haydnhaus, Bonn (Germany); Greven, M. [Medeco Zahnklinik, Bonn (Germany)

    2002-11-01

    Uebereinstimmungen wurden mittels kappa-Statistik geprueft. Ergebnisse: In 56% wurde eine Aenderung des Therapieplans nach MRT registriert. Eine messbare Konkordanz in der Auswertung fand sich fuer anteriore Diskusposition (kappa 0,44), transversale Diskusposition (kappa 0,46) und Kondylusstellung (0,45). Eine schlechte Konkordanz fand sich bei Signalveraenderungen des Diskus (kappa 0,14) und der bilaminaeren Zone (0,24), knoechernen Veraenderungen (0,13) und Zusatzbefinden (0,29). Diskussion: Die MRT des Kiefergelenkes hat einen messbaren Einfluss auf das therapeutische Vorgehen bei kraniomandibulaerer Dysfunktion (Internal Derangement). In der MRT-Beurteilung der Kriterien Diskusposition und Kondylusstellung kann von einer validen Reproduzierbarkeit ausgegangen werden. In der Beurteilung der Signalintensitaeten sowie knoecherner Veraenderungen ist mit einer deutlichen Untersucherabhaengigkeit zu rechnen. (orig.)

  19. Determination of cartilage thickness in the ankle joint. MRT (1,5 T) comparative anatomical study; Bestimmung der Knorpeldicke am oberen Sprunggelenk. Eine MRT(1,5 T)-anatomische Vergleichsstudie

    Energy Technology Data Exchange (ETDEWEB)

    Trattnig, S. [Universitaetsklinik fuer Radiodiagnostik, Wien (Austria). Klinische Einrichtung Magnet Resonanz und Abt. fuer Osteoradiologie]|[Ludwig Boltzmann Inst. fuer Radiologische Tumordiagnostik, Wien (Austria); Breitenseher, M.J. [Universitaetsklinik fuer Radiodiagnostik, Wien (Austria). Klinische Einrichtung Magnet Resonanz und Abt. fuer Osteoradiologie]|[Ludwig Boltzmann Inst. fuer Radiologische Tumordiagnostik, Wien (Austria); Huber, M. [Pathologisch-Bakteriologisches Inst. Baumgartner Hoehe, Wien (Austria); Zettl, R. [Orthopaedisches Krankenhaus Gersthof, Wien (Austria); Rottmann, B. [Universitaetsklinik fuer Radiodiagnostik, Wien (Austria). Klinische Einrichtung Magnet Resonanz und Abt. fuer Osteoradiologie]|[Ludwig Boltzmann Inst. fuer Radiologische Tumordiagnostik, Wien (Austria); Haller, J. [Hanuschkrankenhaus, Wien (Austria). Radiologische Abt.; Imhof, H. [Universitaetsklinik fuer Radiodiagnostik, Wien (Austria). Klinische Einrichtung Magnet Resonanz und Abt. fuer Osteoradiologie]|[Ludwig Boltzmann Inst. fuer Radiologische Tumordiagnostik, Wien (Austria)

    1997-04-01

    Purpose: The aim of this study was to evaluate the accuracy of MRI in the measurement of cartilage thickness of the ankle joint in comparison to pathologic and histologic specimens. Patients and methods: The ankle joints of four fresh cadaver feet were imaged on a 1.5 T MR-unit in the coronal plane. Standard T{sub 1}-weighted spin echo (SE) and a T{sub 1}-weighted 3D-GE (FLASH-3D) sequence with fat saturation were applied. Following MR imaging, the talus was explanted and cut parallel to the MR images for macroscopic evaluation and histologic specimens were prepared. MRI measurements of the cartilage thickness of the talus were carried out in two ways: Without and with consideration of a transition zone of intermediate signal intensity between hyperintense cartilage and hypointense cortical bone. The data were compared with the anatomic specimens as the gold standard expressing the difference as a percentage value. On histologic specimens thickness of deep calcified cartilage layer was measured. Results: Measurements without the transition zone showed a mean underestimation of talus cartilage thickness of 46.8% (41.3-52.1) for T{sub 1}-SE and 47.5% (43.1-52.1) for fat saturated FLASH-3D images. Considering the transition zone the mean values were 25.0% (23.1-26.2) and 14.1% (6.7-21.5). The histologic specimens showed a three-fold increase of thickness of deep calcified cartilage layer. Conclusions: Measurements of the cartilage layer of the ankle joint on MR images are only accurate if the transition zone (calcified cartilage layer) is considered and the optimal pulse sequence (FLASH-3D-fat-sat) is applied. (orig.) [Deutsch] Ziel: Die Frage, ob die MRT die Dicke des Knorpels exakt bestimmen kann, wird kontrovers diskutiert. Ziel der Studie war die Bestimmung der Knorpeldicke am oberen Sprunggelenk mit der MRT im Vergleich zum anatomischen Praeparat. Material und Methode: Sprunggelenke von 4 Leichen wurden auf einem 1,5 Tesla MR-Geraet mittels T{sub 1}-betonter Spin

  20. Speziation von Gadolinium-MRT-Kontrastmitteln in Umweltmatrizes

    OpenAIRE

    Lindner, Uwe

    2017-01-01

    Gd-Kontrastmittel werden in der Medizin für die Magnetresonanztomographie (MRT) benötigt, um einen besseren Bildkontrast zu erzielen. Nach der Anwendung gelangen diese Arzneimittel über das Abwasser in die Klärwerke und von dort in die jeweiligen anliegenden Oberflächengewässer. Somit wird es notwendig, den Verbleib der Gd-MRT-Kontrastmittel in der Umwelt zu verfolgen und aufzuklären. In dieser Arbeit werden für die Analyse von Umweltproben Methoden zur Speziesanalytik von Gd-Kontrastmitteln ...

  1. MRT Lattice Boltzmann schemes for confined suspension flows

    NARCIS (Netherlands)

    Sman, van der R.G.M.

    2010-01-01

    We introduce a novel multiple-relaxation time (modified MRT) Lattice Boltzmann scheme for simulation of confined suspension flow. Via careful tuning of the free eigenvalues of the collision operator we can substantially reduce the error in the so-called hydrodynamic radius. Its performance has been

  2. MRT of the locomotor system. 4. rev. and enl. ed.

    International Nuclear Information System (INIS)

    Vahlensieck, Martin; Reiser, Maximilian

    2015-01-01

    The book on MRT of the locomotor system covers the following topics: relevant NMT imaging techniques, spinal cord, shoulder, elbows, wrist and fingers, hip region, knee, lower leg - ankle - foot, temporomandibular joint, skeletal muscles, bone marrow, bone and soft tissue tumors, osteoporosis, sacroiliac joint, jaw and periodontium.

  3. Functional MRT in psychiatry and neurology. 2. rev. and upd. ed.; Funktionelle MRT in Psychiatrie und Neurologie

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, Frank [Universitaetsklinikum Aachen (Germany); Fink, Gereon R. (eds.) [Forschungszentrum Juelich GmbH (Germany); Uniklinik Koeln (Germany)

    2013-08-01

    The book on functional MRT in psychiatry and neurology covers the following topics: (I) Fundamentals: functional neuro-anatomy, fundamentals of NMR imaging, basic research on the clinical use for diagnostics and therapy; basics of morphometry; real-time fMRT, planning and execution of experimental paradigms; data analysis and statistics; reliability and quality of fMRT experiments; eye movement, neuropharmacologic functional imaging, gender dependent effects, age dependent effects, resting state fMRT; meta analyses. (II) Higher brain achievements: movement and action, perception and attention, visual system and object processing, auditory system, executive functions, somatosensoric system, memory, learning and gratification system, functional neuro-anatomy of speech, number processing and calculation, connectivity, social cognition, emotions, olfactory system, functional imaging in the pain research. (III) Disease pattern: dystonia, Parkinson syndrome, Chorea Huntington, aphasia, apraxia, neglect, amnesia, function recovery following apoplexy, schizophrenia, affective disturbances, anxiety and fear, post-traumatic disturbances, hyperactivity syndrome, personality disorder. (IV) Working tools: brain atlas, tool for integrated analyses of structure, functionality and connectivity (SPM anatomy toolbox).

  4. Hydro-MRI for abdominal diagnostics in children; Hydro-MRT in der Darmdiagnostik bei Kindern

    Energy Technology Data Exchange (ETDEWEB)

    Kern, A.; Schunk, K.; Oberholzer, K.; Thelen, M. [Mainz Univ. (Germany). Klinik und Poliklinik fuer Radiologie; Kessler, M. [Mainz Univ. (Germany). Klinik und Poliklinik fuer Kinderchirurgie

    2001-11-01

    Darmkontrastierung mit 1 l Mannitolloesung mittels MRT an einem 1,0-T-System untersucht. Es kamen transversale und coronare atemangehaltene Sequenzen (T2-HASTE-Sequenzen ohne und mit Fettsupprimierung) sowie kontrastmittelverstaerkte T1-FLASH-Sequenzen zum Einsatz. Die Untersuchungen wurden hinsichtlich der Beurteilbarkeit der einzelnen Darmabschnitte, des Ausmasses und Schweregrades entzuendlicher Veraenderungen sowie extraintestinaler Befunde ausgewertet. Ergebnisse: In 21/24 Untersuchungen konnten der komplette Duenndarm, in 15/24 Faellen zusaetzlich Anteile des Dickdarms dargestellt werden. In 3/24 Faellen war die Beurteilbarkeit des terminalen ileums eingeschraenkt. In 3/24 Untersuchungen traten geringe Atemartefakte auf. Folgende Befunde wurden erhoben: Veraenderungen bei M. Crohn (n = 4), ileitis terminalis (n = 3), ileitis terminalis mit Lymphadenitis mesenterialis (n = 1), Kolitis (n = 2), massive Koprostase (n = 1). Extraintestinal wurden Ovarialzysten (n = 3) und ein Pleuraerguss (n = 1) nachgewiesen. In 4 Untersuchungen fand sich freie Fluessigkeit ohne zusaetzliche pathologische Befunde. Bei 5 Untersuchungen konnten keine pathologischen Veraenderungen nachgewiesen werden. Die Untersuchung wurde von den Kindern gut toleriert; Nebenwirkungen durch die Darmkontrastierung wurden nicht beobachtet. (orig.)

  5. 3D MRI of the colon: methods and first results of 5 patients; 3D-MRT des Kolons: Methodik und erste Ergebnisse

    Energy Technology Data Exchange (ETDEWEB)

    Luboldt, W; Bauerfeind, P; Pelkonen, P; Steiner, P; Krestin, G P; Debatin, J F [MRI-Zentrum, Dept. Diagnostische Radiologie, Universitaetsspital, Zurich (Switzerland)

    1997-09-01

    Purpose: `Exoscopic` and endoscopic identification of colorectal pathologies via MRI. Methods: 5 patients (36-88 years), two normal and three with different colorectal pathologies (diverticular disease, polyps and carcinoma of the colon), were examined by MRI after colonoscopy. Subsequent to filling of the colon with a gadolinium-water mixture under MRI-monitoring, 3D-data sets of the colon were acquired in prone and supine positions over a 28 sec breathold interval. Subsequently multiplanar T{sub 1}-weighted 2D-sequences were acquired before and following i.v. administration of Gd-DTPA (0.1 mmol/kg BW). All imaging was performed in the coronal orientation. The 3D-data were interactively analysed based on various displays: Maximum intensity projection (MIP), surface shadowed display (SSD), multiplanar reconstruction (MPR), virtual colonoscopy (VC). Results: All of the colorectal pathologies could be interactively diagnosed by MPR. On MIP images some pathologies were missed. VC presented the morphology of colon haustra as well as of all endoluminally growing lesions in a manner similar to endoscopy. The colon masses showed uptake of contrast media and could thus be differentiated from air or faeces. (orig./AJ) [Deutsch] Ziel: Externe und endoskopische Identifizierung kolorektaler Pathologien mittels MRT. Material und Methoden: 5 Patienten (36-88 Jahre), zwei mit Normalbefund, drei mit verschiedenen kolorektalen pathologischen Befunden (Divertikulose, Polypen, Karzinom), wurden nach der Kolonoskopie mit der MRT untersucht. Dazu wurde das Kolon unter MR-Sichtkontrolle mit einer Gadolinium-Wasser-Mischung gefuellt und als 3D-Datensatz atemangehalten in Bauch- und Rueckenlage aufgenommen. Anschliessend wurden multiplanare, T{sub 1}-gewichtete 2D-Sequenzen vor und nach i.v. Gd-DTPA-Gabe akquiriert. Die 3D-Datensaetze wurden interaktiv unter Zuhilfenahme verschiedener Darstellungsformen analysiert: Maximale Intensitaetsprojektion (MIP), Oberflaechendarstellung

  6. MRT of the knee joint of juvenile footballers. Are there early changes in the knee due to competitive sport?; MRT der Kniegelenke jugendlicher Fussballspieler. Gibt es Fruehveraenderungen von Kniebinnenstrukturen durch Leistungssport?

    Energy Technology Data Exchange (ETDEWEB)

    Wacker, F. [Abt. fuer Radiologische Diagnostik und Nuklearmedizin, Klinikum Steglitz, Freie Univ. Berlin (Germany); Koenig, H. [Abt. fuer Radiologische Diagnostik und Nuklearmedizin, Klinikum Steglitz, Freie Univ. Berlin (Germany); Felsenberg, D. [Abt. fuer Radiologische Diagnostik und Nuklearmedizin, Klinikum Steglitz, Freie Univ. Berlin (Germany); Wolf, K.J. [Abt. fuer Radiologische Diagnostik und Nuklearmedizin, Klinikum Steglitz, Freie Univ. Berlin (Germany)

    1994-02-01

    In a prospective study, the right knee of 21 symptom free juvenile footballers was examined by MRT (group I) and the results were compared with 12 juveniles of similar age but who did not take part in any special sorting activities (group II). A 1.5 Tesla Magnetome with an extremity coil was used. There were no abnormal changes in either group in the cruciate ligaments. The hyaline cartilage medially was about 10% thicker than laterally in both groups but in group I it was, on average, 24.8% thicker than in group II. Increased signals in the centre of the menisci were observed in 8 members of group I and two in group II. 5 on the 8 in group I, but none in group II, also showed an increase in the joint fluid. (orig.) [Deutsch] In einer retrospektiven Studie wurde das rechte Kniegelenk von 21 beschwerdefreien, jungendlichen Fussballspielern (Gruppe I) sowie von 12 altersgleichen Jungendlichen ohne spezielle sportliche Aktivitaeten (Gruppe II) magnetresonanztomographisch untersucht. Die Messungen erfolgten an einem 1,5-Tesla-Magnetom unter Anwendung einer Extremitaetenspule. Keine pathologischen Veraenderungen ergaben sich bei beiden Gruppen im Bereich der Kreuzbaender. Der hyaline Gelenkknorpel zeigte bei beiden Gruppen am medialen Femurkondylus eine um etwa 10% hoehere Dicke als lateral und erweis sich bei Gruppe I im Mittel um 24,8% dicker als bei Gruppe II. Zentrale Meniskus-Signalvermehrungen konnten bei 8 Jugendlichen der Gruppe I sowie bei zwei der Gruppe II nachgewiesen werden. Dabei wiesen 5/8 der Gruppe I, aber keiner der Gruppe II begleitend eine Gelenkfluessigkeitsvermehrung auf. (orig.)

  7. Superconductive MRI system, MRT-50A/SUPER

    International Nuclear Information System (INIS)

    Suzuki, Hirokazu; Goro, Takehiko

    1992-01-01

    The MRI (magnetic resonance imaging) market has been rapidly growing and more than 1,300 MRI systems are now operating in the Japanese domestic market. An upper-middle range MRI market, which is characterized by high-image quality, has newly appeared between the high-end and middle-range market niches since last year. To be competitive in this upper-middle range market, Toshiba has developed a superconductive MRI system, the MRT-50A/SUPER. The new system featured a high-performance actively shielded gradient coil called the TSGC (twin-shielded gradient coil), installed in a compact superconductive magnet. This paper introduces the MRT-50A/SUPER and describes recent developments in MRI technology. (author)

  8. Malignant degeneration of multiple cartilaginous exostosis. Diagnostic significance of MRT

    International Nuclear Information System (INIS)

    Bair, H.J.; Schmitt, R.; Moos, P.; Fellner, F.; Dvorak, O.; Rupprecht, H.; Lenz, M.

    1997-01-01

    In summary it can be said that diagnostic radiology, and particularly MRT, for evaluation of malignant degeneration of cartilaginous extoses is of high importance, also because of the difficulties posed by a biopsy for verification of malignancy. Cases of malignant cartilaginous extosis have a good prognosis at the early stages of the disease, when the extosis still is restricted to the focal region. (Orig./AJ) [de

  9. Comparison of PET and fMRI activation patterns during declarative memory processes; Vergleich von PET und fMRT-Aktivierungsmustern waehrend deklarativer Gedaechtnisvorgaenge

    Energy Technology Data Exchange (ETDEWEB)

    Mottaghy, F.M.; Krause, B.J.; Schmidt, D.; Hautzel, H.; Mueller-Gaertner, H.-W. [Heinrich-Heine-Univ. Duesseldorf (Germany). Klinik fuer Nuklearmedizin; Forschungszentrum Juelich (DE). Klinik fuer Nuklearmedizin (KME); Herzog, H.; Shah, N.J. [Forschungszentrum Juelich (DE). Inst. fuer Medizin (IME); Halsband, U. [Albert-Ludwigs-Univ. Freiburg (Germany). Psychologisches Inst., Neuropsychologie

    2000-11-01

    hochbildhaften Inhaltes zu lernen und dann zu erinnern (visuelle Praesentation). Ergebnisse: Die Gedaechtnisleistung (Anteil der richtigen Assoziationen) der Probanden lag sowohl in der PET- als auch in der fMRT-Studie bei 93%{+-}9,3%. Waehrend des Lernvorgangs wurden sowohl in der PET als auch in der fMRT Aktivierungen im anterioren cingulaeren Kortex, im linken und rechten praefrontalen Kortex und im Praecuneus beobachtet. Nur in der fMRT liess sich waehrend des Lernvorgangs der parahippocampale Kortex mit darstellen. Waehrend der Abfrage zeigten sich Aktivierungen im linken und rechten Praecuneus, im linken praefrontalen Kortex sowie im anterioren cingulaeren Kortex. Unterschiede finden sich hier vor allem im Bereich des praefrontalen Kortex, da in der fMRT frontalpolare Areale aufgrund von Suszeptibilitaetsartefakten nicht darstellbar sind. Die lokalen Maxima der kortikalen Regionen, die in beiden Bildgebungsmodalitaeten darstellbar sind, lagen im Mittel 7,2{+-}6,5 mm auseinander. Schlussfolgerung: Die Gemeinsamkeiten in den Aktivierungsmustern in der PET und der fMRT ueberwiegen. Die Wahl der Bildgebungsmodalitaet fuer eine Aktivierungsstudie sollte u.a. abhaengig vom Design (Einzelsubjekt vs. Gruppenstudie) und untersuchter kortikaler bzw. subkortikaler Struktur (Suszeptabilitaet, Signalaufloesung) getroffen werden. (orig.)

  10. MRI of the fetal abdomen; MRT des fetalen Abdomens

    Energy Technology Data Exchange (ETDEWEB)

    Hoermann, M.; Brugger, P.C.; Witzani, L.; Prayer, D. [Medizinische Universitaet Wien (Austria). Universitaetsklinik fuer Radiodiagnostik

    2006-02-15

    Magnetic resonance imaging (MRI) is an important diagnostic component for central nervous system and thoracic diseases during fetal development. Although ultrasound remains the method of choice for observing the fetus during pregnancy, fetal MRI is being increasingly used as an additional technique for the accurate diagnosis of abdominal diseases. Recent publications confirm the value of MRI in the diagnosis of fetal gastrointestinal tract and urogenital system diseases. The following report provides an overview of MRI-examination techniques for the most frequent diseases of the abdomen. (orig.) [German] Die MRT ist ein wichtiger Bestandteil zur Diagnostik des zentralen Nervensystems und thorakaler Erkrankungen in der fetalen Entwicklung. Wenngleich der Ultraschall die Methode der Wahl zur Ueberwachung des Feten in der Schwangerschaft bleibt, bekommt die fetale MRT als zusaetzliche Untersuchungstechnik zur akkuraten Diagnostik abdomineller Erkrankungen immer groessere Bedeutung. Die neueren Publikationen bestaetigen v. a. den Stellenwert der MRT in der Diagnose von Erkrankungen des fetalen Gastrointestinaltrakts und des Urogenitalsystems. Im Folgenden soll ein Ueberblick ueber die MR-Untersuchungstechnik der haeufigsten Erkrankungen des Abdomens gegeben werden. (orig.)

  11. Cine MRI of the temporomandibular joint in comparison to static MRI and axiography; Cine-MRT des Kiefergelenks im Vergleich zur konventionellen MRT und Achsiographie

    Energy Technology Data Exchange (ETDEWEB)

    Beer, A.; Rummeny, E.J. [Inst. fuer Roentgendiagnostik der Technischen Univ. Muenchen, Klinikum rechts der Isar (Germany); Kolk, A.; Neff, A. [Klinik und Poliklinik fuer Mund-Kiefer-Gesichtschirurgie der Technischen Univ. Muenchen, Klinikum rechts der Isar (Germany); Hof, N. [Abt. fuer Diagnostische und Interventionelle Radiologie/Nuklearmedizin, Krankenhaus Dritter Orden, Muenchen-Nymphenburg (Germany); Treumann, T. [Roentgeninstitut, Kantonshospital Luzern (Switzerland)

    2004-04-01

    Purpose: To evaluate Cine MRI (cMRI) of the temporomandibular joint in comparison to static MRI (sMRI) and axiography. Materials and Methods: In a prospective study with 57 healthy volunteers as well as 33 patients after temporomandibular joint (TMJ) surgery or with severe joint dysfunction, we measured the mobility of both condyle and disc as well as the sagittal angle of condylar inclination with sMRI and cMRI. Measurements and image analysis were performed by a radiologist and a maxillofacial surgeon in consensus. The results of axiography served as standard of reference. Result: Concerning the assessment of the discoligamentous complex, sMRI was superior to cMRI in the patient-group (sensitivity sMRI 85%, cMRI 76%), while no significant difference was found in the volunteer-group (sensitivity sMRI 97.4%, cMRI 98.3%). The results of cMRI and sMRI showed a highly significant correlation with each other, as well as with the axiographic reference tracings (r=0.90). The average mobility of the disc and condyle was 6% and 10% higher in sMRI compared to cMRI (p=0.001) and showed a slightly higher variance (0.043 vs. 0.038). Concerning the condylar inclination angle, both MRI-procedures had the best correlation (r=0.94) with each other and axiography. Conclusion: Real-time MRI of the TMJ is comparable to axiography in its accuracy and is a useful adjunct to conventional static MRI. (orig.) [German] Fragestellung: Evaluation der Cine-MRT (cMRT) des Kiefergelenks im Vergleich zur statischen MRT (sMRT) und Achsiographie. Material und Methode: Bei 57 Probanden und bei 33 Patienten nach operativem Gelenkeingriff oder mit klinischer Funktionsstoerung wurden die Kondylus- und Diskusmobilitaet sowie die horizontale Kondylenbahnneigung (HKN) in der sMRT und in der cMRT bestimmt. Die Auswertung erfolgte durch einen Radiologen und einen Mund-Kiefer-Gesichtschirurgen im Konsensus. Die Werte der Achsiographie dienten als Goldstandard. Ergebnisse: Bezueglich der Abgrenzbarkeit des

  12. Pathological changes of the chemosensory function in multiple sclerosis. An MRI study; Pathologische Veraenderungen der Chemosensorik mittels Kernspintomografie bei Multipler Sklerose. Eine MRT-Studie

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, F.A.; Harms, L. [Charite Campus Mitte, Berlin (Germany). Dept. of Neurology - Consultation Service for Multiple Sclerosis; Fleiner, F.; Dahlslett, B.; Goektas, Oe. [Charite Campus Mitte, Berlin (Germany). Dept. of Otolaryngology, Head and Neck Surgery; Bohner, G.; Erb, K.; Luedemann, L. [Charite Campus Mitte, Berlin (Germany). Dept. of Radiology

    2011-06-15

    Purpose: To examine possible causes for olfactory and gustatory dysfunction in MS patients in a prospective study with MRI. Materials and Methods: 30 MS patients (21 women, 11 men, 22 - 65 years, diameter 42 years) were examined by MRI. The olfactory bulb (OB) and olfactory brain volume was correlated with the number and volume of MS lesions in the olfactory brain and the non-olfactory brain. Olfactory testing was performed using the Threshold-Discrimination-Identification Test (TDI), and gustatory function was tested using the Taste-Strips-Test (TST). Results: 33 % of the MS patients displayed olfactory dysfunction (8 % of the control group), and 17 % displayed gustatory dysfunction (5 % of the control group). There was a correlation between the olfactory brain volume and the number (r = -0.38, p < 0.05) and volume (r = -0.38, p < 0.05) of MS lesions in the olfactory brain. The olfactory brain volume correlated with the number of MS lesions in the non-olfactory brain (r = -0.48, p < 0.05). The volume of the left OB correlated with the volume of MS lesions in the olfactory brain (r = -0.42, p < 0.05), the number (r = 0.37, p < 0.05) and volume (r = 0.4, p < 0.05) of lesions in the left part of the olfactory brain and with the TST score (r = -0.45, p < 0.05). The TST score correlated with the volume of lesions in the left (r = -0.45, p < 0.05) and right part (r = -0.53, p < 0.05) of the olfactory brain. The TST score correlated with the number of lesions in the non-olfactory brain (r = -0.48, p < 0.05). Conclusion: The correlation between a higher number and volume of MS lesions in the olfactory brain with a decreased OB and olfactory brain volume could help to explain olfactory and gustatory dysfunction in MS patients. Just the left OB correlated with the number and volume of lesions in the olfactory brain. Manual segmentation was a suitable method for measuring OB and olfactory brain volume. (orig.)

  13. Functional MRI of the pelvic floor: postpartum changes of primiparous women after spontaneous vaginal delivery; Funktionelle Magnetresonanztomographie (MRT) des Beckenbodens: Postpartale Veraenderungen bei Erstgebaerenden nach vaginaler Spontangeburt

    Energy Technology Data Exchange (ETDEWEB)

    Lienemann, A.; Fischer, T.; Reiser, M. [Inst. fuer Klinische Radiologie, Klinikum der Univ. Muenchen (Germany); Anthuber, C. [Klinik und Poliklinik fuer Geburtshilfe und Frauenheilkunde, Klinikum der Univ. Muenchen/Grosshadern (Germany)

    2003-08-01

    Purpose: Detection of morphological and functional changes of the pelvic floor with functional MRI in primiparous women after spontaneous vaginal delivery. Methods and Materials: The study comprises 26 primiparous women after vaginal delivery and a control group of 41 healthy asymptomatic nulliparous volunteers. MRI was performed on a 1.5 T system in supine position with vagina and rectum opacified with Sonogel. The static images consisted of sagittal and axial T{sub 2}-weighted SE sequences and functional images of true FISP sequences in midsagittal and axial planes acquired with the patient at rest, straining and during defecation. Evaluation of morphometric parameters included pelvimetry, thickness of the puborectal muscle and width of the urogenital hiatus as well as position and movement of the pelvic organs relative to the pubococcygeal reference line. Results: The configuration of the bony pelvis did not differ for both groups. The puborectal muscle was significantly thinner in the study group (0.8 cm vs 0.6 cm). The functional images showed no significant differences between both groups at rest but a significantly increased incidence in the descent of the bladder neck, vaginal fornix and anorectal junction in the study group during straining. In addition, the primiparous women had more prominent rectoceles (0.6 cm vs 1.5 cm). Conclusion: Static imaging alone fails to demonstrate relevant pelvic floor changes and a functional method is necessary to evaluate the interactions of the pelvic organs regarding organ descent. Functional MRI of the pelvic floor is an excellent method to reveal the significant changes of the pelvic floor after vaginal birth without exposing the uterus to radiation. (orig.) [German] Ziel: Darstellung von morphologischen und funktionellen Veraenderungen am Beckenboden bei Erstgebaerenden nach spontanvaginaler Entbindung mittels funktioneller MRT. Methodik: Funktionelle MRT des Beckenbodens von 26 Erstgebaerenden nach vaginaler

  14. Anatomy of the fingers in MR imaging using a high resolution surface coil; Die Anatomie der Finger in der MRT unter Anwendung einer Hochaufloesungsspule

    Energy Technology Data Exchange (ETDEWEB)

    Maeurer, J. [Strahlenklinik und Poliklinik, Klinikum Rudolf Virchow, Standort Wedding, Freie Univ. Berlin (Germany); Mueller, H.F. [Strahlenklinik und Poliklinik, Klinikum Rudolf Virchow, Standort Wedding, Freie Univ. Berlin (Germany); Lemke, A.J. [Strahlenklinik und Poliklinik, Klinikum Rudolf Virchow, Standort Wedding, Freie Univ. Berlin (Germany); Requardt, R. [Siemens AG, Erlangen (Germany); Stein, I. [Strahlenklinik und Poliklinik, Klinikum Rudolf Virchow, Standort Wedding, Freie Univ. Berlin (Germany); Schedel, H. [Strahlenklinik und Poliklinik, Klinikum Rudolf Virchow, Standort Wedding, Freie Univ. Berlin (Germany); Langer, R. [Strahlenklinik und Poliklinik, Klinikum Rudolf Virchow, Standort Wedding, Freie Univ. Berlin (Germany); Felix, R. [Strahlenklinik und Poliklinik, Klinikum Rudolf Virchow, Standort Wedding, Freie Univ. Berlin (Germany)

    1994-12-31

    MR-images of the fingers of twenty healthy volunteers were obtained at a 1,5-T whole-body system with a high resolution coil. Additionally, the fingers of two formalin-fixed anatomical specismen were imaged, fronzen and then subsequently sectioned for anatomic correlation. Measurements were recorded with a slice thickness of 2 mm. A 256x256 matrix and a 2,5 cam fiel of view (FOV) were used resulting in a pixel size of 0,01 mm{sup 2}. Based on the excellent depiction of anatomic detail and contrast resolution high resolution MRI of the fingers enabled identification of osseous and cartilaginous structures, as well as delineation of tendons, ligaments blood-vessels and dermal layers. (orig.) [Deutsch] An einem 1,5-T-Ganzkoerpertomographen wurden die Finger von 20 gesunden Probanden mit einer Hochaufloesungsspule zur Darstellung der Anatomie untersucht. Zum Vergleich erfolgte die Abbildung der anatomischen Strukturen an zwei formol- und alkoholfixierten Leichepraeparaten der Hand mittels MRT. Im Anschluss wurden die untersuchten Regionen am tiefgefrorenen Praeparat mit einer Bandsaege nachgeschnitten. Die MR-Messungen wurden mit einer Schichtdicke von 3 mm, einem Field of View (FOV) von 25 mm und einer Matrix von 256x256 Pixel durchgefuehrt. Die daraus resultierende Pixelgroesse betrug 0,01 mm{sup 2}. Der Weichteilkontrast und die hohe Ortsaufloesung ermoeglichten die Identifikation von Knochen- und Knorpelstrukturen sowie die Abgrenzung von Sehnen, Baendern, Blutgefaessen und Hautschichten. (orig.)

  15. MRI of pulmonary embolism; MRT der akuten Lungenembolie

    Energy Technology Data Exchange (ETDEWEB)

    Fink, C.; Schoenberg, S.O. [Universitaetsklinikum Mannheim, Medizinische Fakultaet Mannheim der Universitaet Heidelberg, Institut fuer Klinische Radiologie, Mannheim (Germany); Thieme, S.; Clevert, D.; Reiser, M.F. [Klinikum Grosshadern der Ludwig-Maximilians-Universitaet Muenchen, Institut fuer Klinische Radiologie, Muenchen (Germany); Ley, S. [Deutsches Krebsforschungszentrum Heidelberg, Abteilung Radiologie, Heidelberg (Germany); Universitaetsklinikum Heidelberg, Abteilung Paediatrische Radiologie, Heidelberg (Germany); Kauczor, H.U. [Deutsches Krebsforschungszentrum Heidelberg, Abteilung Radiologie, Heidelberg (Germany)

    2007-08-15

    Recent technical developments have substantially improved the potential of MRI for the diagnosis of pulmonary embolism. On the MR scanner side this includes the development of short magnets and dedicated whole-body MRI systems, which allow a comprehensive evaluation of pulmonary embolism and deep venous thrombosis in a single exam. The introduction of parallel imaging has substantially improved the spatial and temporal resolution of pulmonary MR angiography. By combining time-resolved pulmonary perfusion MRI with high-resolution pulmonary MRA a sensitivity and specificity of over 90% is achievable, which is comparable to the accuracy of CTA. Thus, for certain patient groups, such as patients with contraindications to iodinated contrast media and young women with a low clinical probability for pulmonary embolism, MRI can be considered as a first-line imaging tool for the assessment of pulmonary embolism. (orig.) [German] Technische Weiterentwicklungen der MRT haben deren Moeglichkeiten fuer die Diagnostik der Lungenembolie erheblich verbessert. Hierzu zaehlen auf Geraeteseite kuerzere Magneten sowie dedizierte Ganzkoerper-MRT-Systeme, die einerseits den Patientenzugang beguenstigen und andererseits eine Abklaerung einer potenziell zugrunde liegenden Venenthrombose in einer Untersuchung ermoeglichen. Auf Seite der Sequenztechnik hat die Einfuehrung der parallelen Bildgebung die raeumliche und zeitliche Aufloesung der MR-Angiographie (MRA) der Lunge deutlich verbessert. Durch eine Kombination zeitaufgeloester Messungen der Lungenperfusion und einer raeumlich hochaufgeloesten MRA kann fuer die Diagnostik der Lungenembolie eine Sensitivitaet und Spezifitaet von ueber 90% erzielt werden, was vergleichbar der Genauigkeit der CT-Angiographie (CTA) ist. Daher kann die MRT fuer bestimmte Personen, wie z. B. Patienten mit Kontraindikationen gegen jodhaltige Roentgenkontrastmittel (z. B. Hyperthyreose) oder juengere Frauen mit einer geringen klinischen Wahrscheinlichkeit fuer

  16. MRI in neuromuscular disorders; MRT bei neuromuskulaeren Erkrankungen

    Energy Technology Data Exchange (ETDEWEB)

    Fischmann, Arne [Klinik St. Anna, Luzern (Switzerland). Inst. fuer Radiologie und Nuklearmedizin; Fischer, Dirk [Kantonsspital Bruderholz (Switzerland)

    2014-03-15

    Neuromuscular disorders are caused by damage of the skeletal muscles or supplying nerves, in many cases due to a genetic defect, resulting in progressive disability, loss of ambulation and often a reduced life expectancy. Previously only supportive care and steroids were available as treatments, but several novel therapies are under development or in clinical trial phase. Muscle imaging can detect specific patterns of involvement and facilitate diagnosis and guide genetic testing. Quantitative MRT can be used to monitor disease progression either to monitor treatment or as a surrogate parameter for clinical trails. Novel imaging sequences can provide insights into disease pathology and muscle metabolism. (orig.)

  17. MR imaging of the prostate; MRT der Prostata

    Energy Technology Data Exchange (ETDEWEB)

    Asbach, P.; Haas, M.; Hamm, B. [Charite Campus Benjamin Franklin, Klinik fuer Radiologie, Berlin (Germany)

    2015-12-15

    Prostate cancer is the most common form of cancer in men in Germany; however, there is a distinct difference between incidence and mortality. The detection of prostate cancer is based on clinical and laboratory testing using serum prostate-specific antigen (PSA) levels and transrectal ultrasound with randomized biopsy. Multiparametric MR imaging of the prostate can provide valuable diagnostic information for detection of prostate cancer, especially after negative results of a biopsy prior to repeat biopsy. In addition the use of MR ultrasound fusion-guided biopsy has gained in diagnostic importance and has increased the prostate cancer detection rate. The prostate imaging reporting and data system (PI-RADS) classification has standardized the reporting of prostate MRI which has positively influenced the acceptance by urologists. (orig.) [German] Das Prostatakarzinom ist in Deutschland die haeufigste Krebserkrankung des Mannes, wobei ein deutlicher Unterschied zwischen Inzidenz und Mortalitaet besteht. Die Detektion des Prostatakarzinoms basiert auf klinischer und laborchemischer Untersuchung (prostataspezifisches-Antigen[PSA]-Wert) sowie der transrektalen Ultraschalluntersuchung mit randomisierter Biopsie. Die multiparametrische MR-Tomographie kann zur Detektion des Prostatakarzinoms, insbesondere bei negativer Biopsie vor einer erneuten Biopsie wertvolle diagnostische Informationen liefern. Zudem wird zunehmend die MRT-Ultraschall-Fusionsbiopsie in der Diagnostik eingesetzt, wodurch die Detektionsrate des Prostatakarzinoms deutlich gesteigert werden kann. Mit Einfuehrung der PI-RADS-Klassifikation (Prostate Imaging-Reporting and Data System) konnte zudem eine Standardisierung der Befundung erreicht werden, was die Akzeptanz der MRT der Prostata in der Urologie erhoeht hat. (orig.)

  18. Magnetic resonance tomography and dental radiology (Dental-MRT)

    International Nuclear Information System (INIS)

    Gahleitner, A.; Wien Univ.; Solar, P.; Ertl, L.; Nasel, C.; Homolka, P.; Youssefzadeh, S.; Schick, S.

    1999-01-01

    Purpose: To demonstrate the usefulness of Dental-MRT for imaging of anatomic and pathologic conditions of the mandible and maxilla. Methods: Seven healthy volunteers, 5 patients with pulpitis, 9 patients with dentigerous cysts, 5 patients after tooth transplantation and 12 patients with atrophic mandibles were evaluated. Studies of the jaws using axial T1- and T2-weighted gradient echo and spin echo sequences in 2D and 3D technique have been to performed. The acquired images were reconstructed with a standard dental software package on a workstation as panoramic and cross sectional views of the mandible or maxilla. Results: The entire maxilla and mandibula, teeth, dental pulp and the content of the mandibular canal were well depicted. Patients with inflammatory disease of the pulp chamber demonstrate bone marrow edema in the periapical region. Dentigerous cysts and their relation to the surrounding structures are clearly shown. After contrast media application marked enhancement of the dental pulp can be found. Conclusion: Dental-MRT provides a valuable tool for visualization and detection of dental diseases. (orig.) [de

  19. The prognostic value of quantified MRI at an early stage of Bell's palsy; Der prognostische Wert der dynamischen, kontrastmittelverstaerkten Region-of-Interest-MRT in der Akutphase der idiopathischen Fazialisparese

    Energy Technology Data Exchange (ETDEWEB)

    Kress, B.P.J.; Efinger, K.; Gottschalk, A.; Nissen, S.; Solbach, T.; Baehren, W. [Abt. fuer Radiologie, Bundeswehrkrankenhaus Ulm (Germany); Griesbeck, F.; Goriup, A.; Kornhuber, A.W. [Abt. fuer Neurologie und Psychiatrie, Bundeswehrkrankenhaus Ulm (Germany)

    2002-04-01

    DTPA/kg Koerpergewicht. Der Signalintensitaetsanstieg wurde quantitativ mittels Region of interest (ROI) evaluiert. Die Ergebnisse wurden mit dem klinischen Verlauf und den Resultaten der Elektrophysiologie verglichen. Ergebnisse: Alle 30 Patienten konnten quantitativ ausgewertet werden. Die drei Patienten, die im Verlauf eine chronische Fazialisparese entwickelt haben, wurden mit der MRT am Aufnahmetag erfasst. Die Patienten, die in der MRT Zeichen fuer einen unguenstigen Verlauf zeigten, wiesen in der Elektronenphysiologie ein hochpathologisches Muskelsummenaktionspotenzial auf. Statt mit komplizierten Messalgorithmen liess sich mittels einer einmaligen Messung im inneren Gehoergang eine ausreichend verlaessliche prognostische Aussage machen. Zusammenfassung: Die Region-of-interest-MRT hat zu einem fruehen Zeitpunkt der Erkrankung eine zuverlaessige prognostische Bedeutung. Mit einer im klinischen Alltag einfach durchfuehrbaren quantitativen Messung kann die Prognose in einem Stadium abgeschaetzt werden, an dem eine kausale Therapie noch moeglich ist. (orig.)

  20. Cardiodiagnostic imaging. MRT, CT, echocardiography and other methods

    International Nuclear Information System (INIS)

    Erbel, R.; Kreitner, K.F.; Barkhausen, J.; Thelen, M.

    2007-01-01

    The book presents a differentiated approach to cardiac imaging. The focus is n cardio-MR/-CT and echocardiography. These are highly complex methods involving new equipment, new protocols and indications. The techniques are new and difficult to learn for everybody concerned. MR, CT and echocardiography must always be viewed in the context of other diagnostic methods. The interdisciplinary approach of the book addresses both radiologists and cardiologists and relies on the vast experience of the authors. The book offers more than 500 large high-quality reference images reflecting the latest state of the art. It has amethodological section in which the current methods are described (X-ray, echocardiography, nuclear medicine, angiography, CT, MRT etc.) along with their advantages and shortcomings, and a clinical section in which the main indications are described in the common standardized way (anatomy, clinical picture, interpretation, differential diagnosis). (orig.)

  1. Modern MRI of the small bowell; Moderne MRT des Duenndarms

    Energy Technology Data Exchange (ETDEWEB)

    Scharitzer, M.; Ba-Ssalamah, A. [Medizinische Universitaet Wien, Universitaetsklinik fuer Radiologie und Nuklearmedizin, Wien (Austria)

    2015-12-15

    variety of MR sequences has enabled not only the detection but also the characterization of pathological changes of the small intestine, which are vital for further treatment of these patients. (orig.) [German] Die radiologische Diagnostik von Erkrankungen des Duenndarms wurde in den letzten beiden Jahrzehnten einem dramatischen Wandel unterzogen. Durch rasche Fortschritte mit neuen Behandlungsmethoden und einem zunehmend therapeutischen Fokus auf transmuralen Heilungsprozessen ist eine Gesamtabklaerung des Gastrointestinaltrakts in den Mittelpunkt gerueckt. Durch die Einfuehrung der Endoskopie hat die gastrointestinale Bildgebung mit der Magen-Darm-Passage bzw. dem Enteroklysma mit einer relativ hohen Strahlenbelastung nur bedingte Einsatzmoeglichkeiten gezeigt. Die Entwicklung der Schnittbildverfahren ermoeglichte eine deutlich breitere radiologische Abklaerung abdomineller Erkrankungen. Durch schnelle Untersuchungstechniken sowie einen hohen Weichteilkontrast mit dem grossen Vorteil einer fehlenden Strahlenexposition hat die MRT des Gastrointestinaltrakts zunehmende Bedeutung gewonnen. Bei suffizienter Fuellung des Darmlumens liegt ein grosser Vorteil in der gleichzeitigen Abbildung saemtlicher Darmwandschichten, der perienteralen Strukturen sowie assoziierter abdomineller Veraenderungen. Neue MR-Sequenzen wie diffusionsgewichtete Sequenzen, dynamische Kontrastmittelsequenzen oder die MR-Fluoroskopie ermoeglichen die Detektion morphologischer Veraenderungen mit zusaetzlicher Charakterisierung dieser Darmabschnitte sowie die Beurteilung funktioneller Pathologien mit dynamischer Information ueber eine gestoerte Darmmotilitaet. Aktuelle Richtlinien europaeischer radiologischer und gastroenterologischer Organisationen haben die Bedeutung der Schnittbildverfahren und insbesondere der MRT fuer die Erstdiagnose und das Follow-up bei Patienten mit Morbus Crohn bestaetigt. Durch die Moeglichkeit der Beurteilung aller Darmwandschichten sowie dem Vorhandensein extramuraler

  2. Asymptotic Analysis in MIMO MRT/MRC Systems

    Directory of Open Access Journals (Sweden)

    Zhou Quan

    2006-01-01

    Full Text Available Through the analysis of the probability density function of the squared largest singular value of a complex Gaussian matrix at the origin and tail, we obtain two asymptotic results related to the multi-input multi-output (MIMO maximum-ratio-transmission/maximum-ratio-combining (MRT/MRC systems. One is the asymptotic error performance (in terms of SNR in a single-user system, and the other is the asymptotic system capacity (in terms of the number of users in the multiuser scenario when multiuser diversity is exploited. Similar results are also obtained for two other MIMO diversity schemes, space-time block coding and selection combining. Our results reveal a simple connection with system parameters, providing good insights for the design of MIMO diversity systems.

  3. Magnetic resonance imaging of dilated cardiomyopathy; MRT bei dilatativen Kardiomyopathien

    Energy Technology Data Exchange (ETDEWEB)

    D' Anastasi, M. [Klinikum der Ludwig-Maximilians-Universitaet Muenchen, Campus Grosshadern, Institut fuer Klinische Radiologie, Muenchen (Germany); Greif, M. [Klinikum der Ludwig-Maximilians-Universitaet Muenchen, Campus Grosshadern, Medizinische Klinik und Poliklinik I, Muenchen (Germany); Reiser, M.F.; Theisen, D. [Klinikum der Ludwig-Maximilians-Universitaet Muenchen, Campus Grosshadern, Institut fuer Klinische Radiologie, Muenchen (Germany); Deutsches Zentrum fuer Herzkreislaufforschung (DZHK), Muenchen (Germany)

    2013-01-15

    Dilated cardiomyopathy (DCM) is the most common type of cardiomyopathy with a prevalence of 1 out of 2,500 in adults. Due to mild clinical symptoms in the early phase of the disease, the true prevalence is probably even much higher. Patients present with variable clinical symptoms ranging from mild systolic impairment of left ventricular function to congestive heart failure. Even sudden cardiac death may be the first clinical symptom of DCM. The severity of the disease is defined by the degree of impairment of global left ventricular function. Arrhythmias, such as ventricular or supraventricular tachycardia, atrioventricular (AV) block, ventricular extrasystole and atrial fibrillation are common cardiac manifestations of DCM. Magnetic resonance imaging (MRI) plays an important role in the exact quantification of functional impairment of both ventricles and in the evaluation of regional wall motion abnormalities. With its excellent ability for the assessment of myocardial structure, it is becoming increasingly more important for risk stratification and therapy guidance. (orig.) [German] Die dilatative Kardiomyopathie (DCM) ist die haeufigste Form der Kardiomyopathie mit einer Praevalenz von 1/2500 Erwachsenen. Aufgrund der zunaechst milden klinischen Symptomatik ist jedoch von einer relativ hohen Dunkelziffer auszugehen. Die klinische Praesentation ist variabel, die Schwere der Erkrankung wird vom Ausmass der systolischen Funktionseinschraenkung bestimmt. Herzrhythmusstoerungen, wie ventrikulaere oder supraventrikulaere Tachykardien, AV-Blockierungen, ventrikulaere Extrasystolen und Vorhofflimmern sind moegliche klinische Manifestationen. Bei manchen Patienten ist der ploetzliche Herztod die erste klinische Manifestation der Erkrankung. Die kardiale MRT spielt eine bedeutende Rolle fuer die Beurteilung des Ausmasses der ventrikulaeren Dilatation, Dysfunktion und fuer die Beurteilung regionaler Wandbewegungsstoerungen. Darueber hinaus kann sie zur Anwendung kommen

  4. Rheumatoid arthritis of the wrist; Dynamic Gd-DTPA enhanced MRT. Rheumatoide Arthritis des Handgelenkes; Dynamische Gd-DTPA-verstaerkte MRT

    Energy Technology Data Exchange (ETDEWEB)

    Naegele, M. (Radiologische Universitaetsklinik, Bonn (Germany)); Kunze, V. (Radiologische Universitaetsklinik, Bonn (Germany)); Koch, W. (Orthopaedische Universitaetsklinik, Bonn (Germany)); Bruening, R. (Radiologische Universitaetsklinik, Bonn (Germany)); Seelos, K. (Radiologische Universitaetsklinik, Bonn (Germany)); Stroehmann, I. (Radiologische Universitaetsklinik, Bonn (Germany)); Woell, B. (Radiologische Universitaetsklinik, Bonn (Germany)); Reiser, M. (Radiologische Universitaetsklinik, Bonn (Germany))

    1993-02-01

    21 patients with rheumatoid arthritis of the wrist diagnosed according to the criteria of the American Rheumatism Association were examined by dynamic MRT before and after the i.v. injection of Gd-DTPA (0.1 mmol/kg). The results were correlated with the clinical and radiological findings. The increased signal intensity of the pannus was 1.17[+-]0.45%/sec and this differed significantly (p<0.001) from bone marrow (0.16[+-]0.11%/sec) and from muscle (0.25[+-]0.16%/sec). Blood sedimentation rate correlated with the gradient of synovial proliferation (p<0.05). There were no further statistically significant correlations between the clinical, radiological and MRT findings and the change in signal intensity from synovial proliferation as shown by dynamic MRT. (orig.)

  5. Cerebral activation studies by PET and fMRT, clinical relevance?; Zerebrale Aktivierungsstudien mit PET und fMRT, klinische Relevanz?

    Energy Technology Data Exchange (ETDEWEB)

    Brandt, T. [Neurologische Klinik und Poliklinik, Klinikum Grosshadern, Muenchen Univ. (Germany)

    1997-03-01

    Cerebral activation studies by PET and fMRT will gain increasing clinical relevance for functional neuroanatomy (reading, speaking), localisation of largely unknown cortical functions (vestibular cortex), imaging of subjective complaints of functional impairments (pain, smell, memory), and documentation of neurological rehabilitation at neuronal level (regeneration, compensation, substitution, learning). (orig.) [Deutsch] Zerebrale Aktivierungsstudien mit PET und fMRT erlangen zunehmend klinische Bedeutung fuer die funktionelle Neuroanatomie einzelner und komplexer Hirnleistungen (Lesen, Sprechen), die Lokalisation bislang unzureichend erforschter Hirnfunktionen (vestibulaerer Kortex), die Objektivierung subjektiver Beschwerden und Funktionsausfaelle (Schmerz, Riechen, Gedaechtnis) und die Dokumentation neurologischer Rehabilitation auf neuronaler Ebene (Regeneration, Kompensation, Substitution, Lernen). (orig.)

  6. Objektverfolgung bei einer vollständigen Fahrzeugumfeldüberwachung mittels Radar

    Science.gov (United States)

    Schuster, M.; Pech, T.; Reuter, J.; Wanielik, G.

    2014-11-01

    Für modernste Fahrerassistenzsysteme ist zunehmend eine vollständige Rundumüberwachung des fließenden Verkehrs erforderlich. In diesem Artikel wird ein Ansatz zur Überwachung des gesamten umliegenden Verkehrs mittels Radarsystemen präsentiert. Hierfür wurde ein Versuchsfahrzeug mit insgesamt sechs Radarsensoren ausgerüstet, um eine möglichst hohe Umfeld-Überwachung zu ermöglichen. Für diese Konfiguration wird ein auf GPDA basierendes Trackingsystem vorgestellt. Es wird auf das Problem ausgedehnter Ziele eingegangen, welches auftritt wenn sich ein Fremdfahrzeug neben dem Versuchsfahrzeug befindet, da hier Reflektionen von verschiedenen Reflektionszentren des Ziels aufgefangen werden. Dieser Effekt wird ausgenutzt, um mittels einer Track-zu-Track Fusion eine Längenschätzung des vorbeifahrenden Fahrzeugs zu ermöglichen.

  7. Sentinel-Lymphknoten-Biopsie des Melanoms mittels Indocyaningrün und "FOVIS"-System.

    Science.gov (United States)

    Göppner, Daniela; Nekwasil, Stephan; Jellestad, Anne; Sachse, Alexander; Schönborn, Karl-Heinz; Gollnick, Harald

    2017-02-01

    Der Nachweis metastatischer Infiltrate im Sentinel-Lymphkoten (SLN) gilt als wesentlicher prognostischer Faktor des Melanoms. Alternativ zur Farbstoffmethode mit Patentblau zum Goldstandard der SLN-Biopsie (SLNB) mittels Radiokolloid wird die fluoreszenzoptische Darstellung mit Hilfe von Indocyaningrün (ICG) und Nahinfrarot (NIR)-Kamerasystem kommuniziert. Im Vergleich zur konventionellen Methode wurde die Wertigkeit des ICG-/NIR-Verfahrens in Abhängigkeit vom Body-Mass-Index (BMI) des Patienten und der Konzentration von ICG bezüglich der Visualisierung des Lymphabstroms und des SLNs untersucht. An zehn Patienten wurde die SLNB mittels Technetium-99m, Patentblau und ICG durchgeführt. Die Fluoreszenz-Darstellung von Lymphbahnen und SLN erfolgte in Echtzeit mittels der NIR-Kameratechnik "FOVIS". Je nach erzielter Bildqualität wurde ICG in einer Dosis von 0,25 mg bis 2,5 mg intrakutan appliziert. Neun der zehn SLN wurden fluoreszenzoptisch identifiziert (90 %), alle zehn radioaktiv (100 %), nur acht (80 %) mittels ICG-Grünfärbung bzw. Patenblau-Markierung. Transdermal wurde ein SLN dargestellt (10 %). In Korrelation zum BMI waren höhere ICG-Mengen, bis zu 2,5 mg intrakutan absolut, in der Darstellung der Lymphbahnen von Vorteil. Die SLN-Fluoreszenzmarkierung mit dem ICG/NIR-Kamera-System "FOVIS" stellt eine sichere Alternative zur Farbstoffmethode mit Patentblau ergänzend zur Radiokolloidmethode mit Technetium-99m dar. Weitere Studien zur optimalen Dosierung von ICG und transdermalen Bildgebung in Relation zum BMI sind notwendig. © 2017 Deutsche Dermatologische Gesellschaft (DDG). Published by John Wiley & Sons Ltd.

  8. The diagnosis of inflammatory muscular and vascular conditions using MRT with STIR sequences. Diagnostik entzuendlicher Muskel- und Gefaesserkrankungen in der MRT mit STIR-Sequenzen

    Energy Technology Data Exchange (ETDEWEB)

    Beese, M.S. (Radiologische Klinik, Universitaetskrankenhaus Eppendorf, Hamburg (Germany)); Winkler, G. (Radiologische Klinik, Universitaetskrankenhaus Eppendorf, Hamburg (Germany) Neurologische Klinik, Universitaetskrankenhaus Eppendorf, Hamburg (Germany)); Nicolas, V. (Radiologische Klinik, Universitaetskrankenhaus Eppendorf, Hamburg (Germany)); Maas, R. (Radiologische Klinik, Universitaetskrankenhaus Eppendorf, Hamburg (Germany)); Kress, D. (Radiologische Klinik, Universitaetskrankenhaus Eppendorf, Hamburg (Germany)); Kunze, K. (Radiologische Klinik, Universitaetskrankenhaus Eppendorf, Hamburg (Germany) Neurologische Klinik, Universitaetskrankenhaus Eppendorf, Hamburg (Germany)); Buecheler, E. (Radiologische Klinik, Universitaetskrankenhaus Eppendorf, Hamburg (Germany))

    1993-06-01

    The role of MRT in the prebiopsy diagnosis of muscular and vascular inflammatory conditions was evaluated prospectively and an optimal method of examination was investigated. 92 patients with a suspected diagnosis of myositis (60 cases) or vasculitis (32 cases) were examined, in each case two extremities were studied using transverse T[sub 1] and T[sub 2] weighted SE sequences and double echo STIR sequences on a 0.5 Tesla (56 patients) or 1.5 Tesla magnet (36 patients; T5/S15 Gyroscan, Philips). The site of the biopsy depended on the MRT findings. In 41 patients the suspected diagnosis was confirmed histologically, in two patients an infective myositis was diagnosed on clinical grounds despite negative histology. MRT demonstrated muscle oedema in 86% of patients. There were negative findings after immuno-suppressive therapy (two patients), in focal myositis (3 out of 4 patients) and in one of 7 patients with untreated vasculitis. Amongst 49 patients in whom the suspected diagnosis could not be confirmed there was muscle oedema in 11 cases (9 neuropathies out of 22, two myopathies out of 10). Oedema indicated inflammatory muscular or vascular disease with a sensitivity of 97% (except in treated patients and for focal myositis). The number of false negative biopsies can be greatly reduced by the use of MRT. (orig.)

  9. Magnetic resonance tomography (MRT) of the knee joint: Meniscus, cruciate ligaments and hyaline cartilage. Magnetresonanztomographie (MRT) des Kniegelenks: Meniskus, Kreuzbaender und hyaliner Gelenkknorpel

    Energy Technology Data Exchange (ETDEWEB)

    Hodler, J. (Radiologie, Universitaetsspital, Zurich (Switzerland) Orthopaedische Universitaetsklinik Balgrist, Zurich (Switzerland). Radiologische Abt.); Buess, E. (Orthopaedische Universitaetsklinik Balgrist, Zurich (Switzerland)); Rodriguez, M. (Orthopaedische Universitaetsklinik Balgrist, Zurich (Switzerland)); Imhoff, A. (Orthopaedische Universitaetsklinik Balgrist, Zurich (Switzerland))

    1993-08-01

    The use of MRT for diagnosing injury to the meniscus, the cruciate ligaments and hyaline cartilage was evaluated retrospectively in 82 knee joints without any knowledge of operative findings. In 49 cases the results were verified by arthroscopy and in 33 cases by arthrotomy. Sensitivity, specificity and diagnostic accuracy of MRT for meniscus lesions was 73.9%, 96.9%, and 94.6%. Corresponding values for lesions of the anterior cruciate ligament were 88.9%, 96.6%, and 94.7%, and for lesions of the hyaline cartilage 62.6%, 96.1%, and 87.9%, respectively. In addition to its high specificity, MRT proved accurate in excluding lesions of the meniscus (97.1%) of the anterior cruciate ligament (96.6%) and of hyaline cartilage (88.8%). A negative finding on MRT therefore makes the presence of a lesion of the meniscus, cruciate ligaments of cartilage unlikely. In such cases one is justified in delaying the use of arthroscopy or arthrotomy. (orig.)

  10. Image fusion of MRI and fMRI with intraoperative MRI data: methods and clinical relevance for neurosurgical interventions; Fusion von MRT-, fMRT- und intraoperativen MRT-Daten. Methode und klinische Bedeutung am Beispiel neurochirurgischer Interventionen

    Energy Technology Data Exchange (ETDEWEB)

    Moche, M.; Busse, H.; Dannenberg, C.; Schulz, T.; Schmidt, F.; Kahn, T. [Universitaetsklinikum Leipzig (Germany). Klinik und Poliklinik fuer Diagnostische Radiologie; Schmitgen, A. [GMD Forschungszentrum Informationstechnik GmbH-FIT, Sankt Augustin (Germany); Trantakis, C.; Winkler, D. [Klinik und Poliklinik fuer Neurochirurgie, Universitaetsklinikum Leipzig (Germany)

    2001-11-01

    The aim of this work was to realize and clinically evaluate an image fusion platform for the integration of preoperative MRI and fMRI data into the intraoperative images of an interventional MRI system with a focus on neurosurgical procedures. A vertically open 0.5 T MRI scanner was equipped with a dedicated navigation system enabling the registration of additional imaging modalities (MRI, fMRI, CT) with the intraoperatively acquired data sets. These merged image data served as the basis for interventional planning and multimodal navigation. So far, the system has been used in 70 neurosurgical interventions (13 of which involved image data fusion - requiring 15 minutes extra time). The augmented navigation system is characterized by a higher frame rate and a higher image quality as compared to the system-integrated navigation based on continuously acquired (near) real time images. Patient movement and tissue shifts can be immediately detected by monitoring the morphological differences between both navigation scenes. The multimodal image fusion allowed a refined navigation planning especially for the resection of deeply seated brain lesions or pathologies close to eloquent areas. Augmented intraoperative orientation and instrument guidance improve the safety and accuracy of neurosurgical interventions. (orig.) [German] Ziel dieser Arbeit waren die Realisierung und klinische Bewertung einer Bildfusion praeoperativer MRT- und fMRT-Bilder mit intraoperativen Datensaetzen eines interventionellen MRT-Systems am Beispiel neurochirurgischer Eingriffe. Ein vertikal offenes 0,5-T-MRT-System wurde mit einem erweiterten Navigationssystem ausgestattet, welches eine Integration zusaetzlicher Bildinformationen (Hochfeld-MRT, fMRT, CT) in die intraoperativ akquirierten Datensaetze erlaubt. Diese fusionierten Bilddaten wurden zur Interventionsplanung und multimodalen Navigation verwendet. Bisher wurde das System bei insgesamt 70 neurochirurgischen Eingriffen eingesetzt, davon 13

  11. MRI in dementia-type diseases; MRT bei demenziellen Erkrankungen

    Energy Technology Data Exchange (ETDEWEB)

    Bodea, S.V.; Muehl-Benninghaus, R. [Universitaetsklinikum des Saarlandes, Klinik fuer Diagnostische und Interventionelle Neuroradiologie, Homburg (Germany)

    2015-05-01

    Dementia-inducing conditions represent a leading cause of disability and are a major health concern in industrialized countries. The burden these conditions put on society is certain to rise in the context of an ever-increasing elderly population. As these conditions feature an insidious onset and overlapping clinical features, imaging is a powerful tool in refining the diagnosis and assessing the progression of dementing conditions. The radiologist needs to be aware of and be able to detect underlying pathologies which could be reversible. Furthermore, imaging is important not only in excluding other pathologies but also in improving diagnostic accuracy. This article presents the typical clinical presentations as well as magnetic resonance imaging (MRI) features of the degenerative and the non-degenerative causes of dementia. The focus is on the core knowledge for MRI diagnostics in dementing conditions and a brief presentation of the latest MRI techniques which may become a part of standard imaging protocols in the future. (orig.) [German] Demenzielle Erkrankungen gehoeren in den Industrielaendern zu den haeufigsten Ursachen fuer Beeintraechtigungen im Alltag. Durch eine stetig alternde Population nimmt auch die Belastung fuer die Gesellschaft immer weiter zu. Bei haeufig schleichendem Symptombeginn sowie sich ueberlappender Klinik mit anderen Krankeitsbildern kann die Bildgebung ein gutes Werkzeug zur Praezisierung der Diagnose und Beurteilung eines Progresses sein. Der Radiologe sollte andere und reversible Pathologien erkennen und von demenztypischen Veraenderungen abgrenzen koennen. Dieser Artikel beschreibt typische klinische Symptome und auch bildmorphologische Veraenderungen verschiedener Demenzformen, die durch neurodegenerative und nichtdegenerative Ursachen bedingt sein koennen. Ausserdem werden aktuellste MRT-Techniken vorgestellt. Diese koennten kuenftig im Standartprotokoll zur Bildgebung bei der Abklaerung demenzieller Syndrome verankert sein. (orig.)

  12. CT and MRI normal findings; CT- und MRT-Normalbefunde

    Energy Technology Data Exchange (ETDEWEB)

    Moeller, T.B.; Reif, E. [Caritas-Krankenhaus, Dillingen (Germany)

    1998-07-01

    This book gives answers to questions frequently heard especially from trainees and doctors not specialising in the field of radiology: Is that a normal finding? How do I decide? What are the objective criteria? The information presented is three-fold. The normal findings of the usual CT and MRI examinations are shwon with high-quality pictures serving as a reference, with inscribed important additional information on measures, angles and other criteria describing the normal conditions. These criteria are further explained and evaluated in accompanying texts which also teach the systematic approach for individual picture analysis, and include a check list of major aspects, as a didactic guide for learning. The book is primarily intended for students, radiographers, radiology trainees and doctors from other medical fields, but radiology specialists will also find useful details of help in special cases. (orig./CB) [German] Normalbefunde sind die haeufigsten Befunde ueberhaupt. Also kein Problem? Doch. Besonders Radiologen in der Ausbildung und Aerzte aus anderen Fachgebieten stellen sich immer wieder die entscheidende Frage: Ist das normal? Woran kann ich das erkennen? Wie kann ich das objektivieren? Dieses Buch leistet dreierlei: 1. Es zeigt klassische Normalbefunde der gaengigen CT- und MRT-Untersuchungen in hoher Abbildungsqualitaet als Referenz. Direkt in die Aufnahmen eingezeichnet sind wichtige Daten: Masse, Winkel und andere Kriterien des Normalen. Sie werden im Text nochmals zusammengefasst, erklaert und bewertet. 2. Es lehrt die Systematik der Bildbetrachtung - wie schaue ich mir ein Bild an, welche Strukturen betrachte ich in welcher Reihenfolge und worauf muss ich dabei besonders achten? Dies alles in Form einer uebersichtlichen Checkliste zu jeder Aufnahme. 3. Es gibt eine Befundformulierung vor, die sich wiederum an dem Schema der Bildanalyse orientiert, alle Kriterien des Normalen definiert und dadurch auch ein wichtiges didaktisches Element darstellt

  13. Alignment and position visualization methods for the biomedical imaging and therapy (BMIT) MRT lift

    International Nuclear Information System (INIS)

    Bree, Michael; Miller, Denise; Kerr, Graham; Belev, George; Wysokinski, Tomasz W.; Dolton, Wade

    2016-01-01

    The Microbeam Radiation Therapy (MRT) Lift is an eight stage positioning and scanning system at the Canadian Light Source’s BMIT Facility. Alignment of the sample with the beam using the MRT Lift is a time consuming and challenging task. The BMIT Group has developed a Python-based MRT Lift positioning and control program that uses a combination of computational and iterative methods to independently adjust the sample’s X, Y, Z, pitch and roll positions. The program offers “1-Click” alignment of the sample to the beam. Use of a wireframe visualization technique enables even minute movements to be illustrated. Proposed movements and the resulting MRT Lift position can be manually verified before being applied. Optional integration with the SolidWorks modelling platform allows high quality renderings of the MRT Lift in its current or proposed position to be displayed in real time. Human factors principles are incorporated into the program with the objective of delivering easy to use controls for this complex device.

  14. Alignment and position visualization methods for the biomedical imaging and therapy (BMIT) MRT lift

    Energy Technology Data Exchange (ETDEWEB)

    Bree, Michael, E-mail: michael.bree@lightsource.ca; Miller, Denise; Kerr, Graham; Belev, George; Wysokinski, Tomasz W.; Dolton, Wade [Canadian Light Source Inc., 44 Innovation Blvd, Saskatoon, SK S7N 2V3 Canada (Canada)

    2016-07-27

    The Microbeam Radiation Therapy (MRT) Lift is an eight stage positioning and scanning system at the Canadian Light Source’s BMIT Facility. Alignment of the sample with the beam using the MRT Lift is a time consuming and challenging task. The BMIT Group has developed a Python-based MRT Lift positioning and control program that uses a combination of computational and iterative methods to independently adjust the sample’s X, Y, Z, pitch and roll positions. The program offers “1-Click” alignment of the sample to the beam. Use of a wireframe visualization technique enables even minute movements to be illustrated. Proposed movements and the resulting MRT Lift position can be manually verified before being applied. Optional integration with the SolidWorks modelling platform allows high quality renderings of the MRT Lift in its current or proposed position to be displayed in real time. Human factors principles are incorporated into the program with the objective of delivering easy to use controls for this complex device.

  15. MUNICIPAL BONDS AS THE FINANCING STRATEGY FOR URBAN INFRASTRUCTURE : CASE STUDY OF JAKARTA MRT

    Directory of Open Access Journals (Sweden)

    Eko Nur Surachman

    2016-10-01

    Full Text Available The construction of Jakarta MRT Phase I has been carried out by using funds from foreign debt. Meanwhile, Jakarta MRT Phase II or other local infrastructure projects are still waiting for new funding scheme. One alternative is municipal bonds. This study investigate the possibilities of using municipal bonds to finance urban infrastructure project with the case study of Jakarta MRTPhase I. The analyzed use three perspectives including financial aspect, legal aspect, and Jakarta financial capacity aspect. financial analysis using discounted cash flow (DCF, net present value (NPV and internal rate of return (IRR.Secondly, study literature is used in the legal analysis by exploring specific regulations regarding the municipal bonds. Finally, the Jakarta Regional Budget and Jakarta Budget Audit Report is examined to get insight and depth information regarding its financial capacity. The result is municipal bonds are feasible as the source of financing Jakarta MRT Project.

  16. Muscle lesion comparing of imaging procedures (sonography and MRT) -experimental and clinical study

    International Nuclear Information System (INIS)

    Mellerowicz, H.; Lubasch, A.; Dulce, M.; Wagner, S.; Paul, B.

    1993-01-01

    Muscle injuries in sports are more common now. Diagnosis and follow up of muscle injuries is nowadays achieved by sonography and MRT. In order to assess the two imagine procedures, a direct test for comparison of sonography and MRT was performed in an experimental study: A standardised disconnection of m. triceps surae in rats was either sutured and glued or not treated. Clinical studies were performed in 26 patients suffering from muscle trauma. Sonography was proved to be a reliable procedure especially in follow up control until full weight bearing and should be used first. Negative or doubtfull findings require further investigation by MRT. Especially contrast medium (Gd-DTPA) assisted examinations enables a long term follow up and may even show small (muscle strain) and deep lying injuries. (orig.) [de

  17. Multiparametric and molecular imaging of breast tumors with MRI and PET/MRI; Multiparametrische und molekulare Bildgebung von Brusttumoren mit MRT und PET-MRT

    Energy Technology Data Exchange (ETDEWEB)

    Pinker, K. [Medizinische Universitaet Wien, Universitaetsklinik fuer Radiologie und Nuklearmedizin, Division fuer Molekulare und Gender Bildgebung, Wien (Austria); Memorial Sloan-Kettering Cancer Center, Department of Radiology, Molecular Imaging and Therapy Service, New York (United States); State University of Florida, Department of Scientific Computing in Medicine, Florida (United States); Marino, M.A. [Medizinische Universitaet Wien, Universitaetsklinik fuer Radiologie und Nuklearmedizin, Division fuer Molekulare und Gender Bildgebung, Wien (Austria); Policlinico Universitario G. Martino, University of Messina, Department of Biomedical Sciences and Morphologic and Functional Imaging, Messina (Italy); Meyer-Baese, A. [State University of Florida, Department of Scientific Computing in Medicine, Florida (United States); Helbich, T.H. [Medizinische Universitaet Wien, Universitaetsklinik fuer Radiologie und Nuklearmedizin, Division fuer Molekulare und Gender Bildgebung, Wien (Austria)

    2016-07-15

    Magnetic resonance imaging (MRI) of the breast is an indispensable tool in breast imaging for many indications. Several functional parameters with MRI and positron emission tomography (PET) have been assessed for imaging of breast tumors and their combined application is defined as multiparametric imaging. Available data suggest that multiparametric imaging using different functional MRI and PET parameters can provide detailed information about the hallmarks of cancer and may provide additional specificity. Multiparametric and molecular imaging of the breast comprises established MRI parameters, such as dynamic contrast-enhanced MRI, diffusion-weighted imaging (DWI), MR proton spectroscopy ({sup 1}H-MRSI) as well as combinations of radiological and MRI techniques (e.g. PET/CT and PET/MRI) using radiotracers, such as fluorodeoxyglucose (FDG). Multiparametric and molecular imaging of the breast can be performed at different field-strengths (range 1.5-7 T). Emerging parameters comprise novel promising techniques, such as sodium imaging ({sup 23}Na MRI), phosphorus spectroscopy ({sup 31}P-MRSI), chemical exchange saturation transfer (CEST) imaging, blood oxygen level-dependent (BOLD) and hyperpolarized MRI as well as various specific radiotracers. Multiparametric and molecular imaging has multiple applications in breast imaging. Multiparametric and molecular imaging of the breast is an evolving field that will enable improved detection, characterization, staging and monitoring for personalized medicine in breast cancer. (orig.) [German] Die Magnetresonanztomographie (MRT) der Brust ist ein etabliertes nichtinvasives bildgebendes Verfahren mit vielfaeltigen Indikationen. In den letzten Jahren wurden zahlreiche funktionelle MRT- und Positronenemissionstomographie(PET)-Parameter in der Brustbildgebung evaluiert, und ihre kombinierte Anwendung ist als multiparametrische Bildgebung definiert. Bisherige Daten legen nahe, dass die multiparametrische Bildgebung mit MRT und PET

  18. MRI of the fingers in patients with systemic scleroderma. Early results of contrast-enhanced examinations on a dedicated MRI system; MRT der Finger bei systemischer Sklerodermie. Erste Ergebnisse mit kontrastverstaerkten Untersuchungen an einem dedizierten MRT-System

    Energy Technology Data Exchange (ETDEWEB)

    Bonel, H.; Seemann, M.; Reiser, M. [Inst. fuer Radiologische Diagnostik, Klinikum Grosshadern, Univ. Muenchen (Germany); Messer, G.; Walchner, M.; Roecken, M. [Dermatologische Klinik und Poliklinik, Univ. Muenchen (Germany)

    1997-10-01

    Purpose. To estimate disease activity in patients with systemic sclerosis using contrast-enhanced MRI of the skin. Material and Methods. In a pre-study, sequences of a low-field (0.2 T) scanner (Artoscan, Esaote, Genova, Italy) were optimized for detection of intravenous contrast (0.1 mmol/l Gd-DTPA) in six patients with the autoimmune disease systemic scleroderma. Based on the results of the pre-study, 17 patients with scleroderma (7 sclerotic/10 active inflammatory disease) were scanned using gradient-spoiled 3D GRE sequences (FA 90 , TR 100 ms, TE 18 ms), which had been established as most sensitive for intravenous contrast. Contrast enhancement of the skin was determined quantitatively by contrast-to-noise ratios (CNR), comparing post- to pre-contrast and dynamic scans (for 6 min, 1 acquisition/min). Patients in the chronic state with sclerodactylia and active inflammation of the hands were considered separately and compared to a control group (n=10) matched according to age. Results. CNR increase after intravenous contrast was significantly higher in patients with active disease (86{+-}16% increase) than sclerosing disease (29{+-}3%, p<0.05) and the control group (4{+-}2%, p<0.05). The dynamic examination showed a significantly slower decrease after the peak rise in the first minute in patients with active disease (CNR 15.4{+-}0.7 to 14.2{+-}1.4) than in those with chronic disease (14.1{+-}0.5 to 11.3{+-}0.9, p<0.05). (orig.) [Deutsch] Zielsetzung der Arbeit war die Quantifizierung der Entzuendungsreaktion der Haut bei an systemischer Sklerodermie erkrankten Patienten mittels kontrastverstaerkter MRT. Material und Methoden. In einer Vorstudie mit 6 Patienten wurden die Sequenzen eines dedizierten Niederfeldmagnetresonanztomographen (Artoscan, Esaote, Genua, Italien) fuer den Kontrastmittelnachweis (0,1 mmol/l Gd-DTPA i.v.) optimiert. Basierend auf dieser Sequenzoptimierung wurden 17 Patienten mit systemischer Sklerodermie (7 Patienten mit sklerosierender, 10

  19. Typisierung von HLA-Klasse-II-Merkmalen mittels des TaqMan-Verfahrens

    OpenAIRE

    Tremmel, Matthias

    2001-01-01

    In Anlehnung an die konventionelle SSP-PCR-Methode wurde ein Low-Resolution-Panel mittels des TaqMan-Prinzips entwickelt und es wurde exemplarisch für DR4 und DR15/16 gezeigt, daß die auf dem 5 Nuklease-Assay beruhende Methode fähig ist, auch einzelne Punktmutationen voneinander zu unterscheiden. Das Grundprinzip dieser Methode basiert ähnlich dem der PCR-SSP auf dem Verfahren der PCR und auf dem Ausnutzen genetischer Unterschiede. So kommt es nur zu einer Amplifizierung wenn beide Primer spe...

  20. Functional MRT in psychiatry and neurology. 2. rev. and upd. ed.

    International Nuclear Information System (INIS)

    Schneider, Frank; Fink, Gereon R.

    2013-01-01

    The book on functional MRT in psychiatry and neurology covers the following topics: (I) Fundamentals: functional neuro-anatomy, fundamentals of NMR imaging, basic research on the clinical use for diagnostics and therapy; basics of morphometry; real-time fMRT, planning and execution of experimental paradigms; data analysis and statistics; reliability and quality of fMRT experiments; eye movement, neuropharmacologic functional imaging, gender dependent effects, age dependent effects, resting state fMRT; meta analyses. (II) Higher brain achievements: movement and action, perception and attention, visual system and object processing, auditory system, executive functions, somatosensoric system, memory, learning and gratification system, functional neuro-anatomy of speech, number processing and calculation, connectivity, social cognition, emotions, olfactory system, functional imaging in the pain research. (III) Disease pattern: dystonia, Parkinson syndrome, Chorea Huntington, aphasia, apraxia, neglect, amnesia, function recovery following apoplexy, schizophrenia, affective disturbances, anxiety and fear, post-traumatic disturbances, hyperactivity syndrome, personality disorder. (IV) Working tools: brain atlas, tool for integrated analyses of structure, functionality and connectivity (SPM anatomy toolbox).

  1. Cerebral activation studies by PET and fMRT, clinical relevance?

    International Nuclear Information System (INIS)

    Brandt, T.

    1997-01-01

    Cerebral activation studies by PET and fMRT will gain increasing clinical relevance for functional neuroanatomy (reading, speaking), localisation of largely unknown cortical functions (vestibular cortex), imaging of subjective complaints of functional impairments (pain, smell, memory), and documentation of neurological rehabilitation at neuronal level (regeneration, compensation, substitution, learning). (orig.) [de

  2. Konferenz Stadtmusikgeschichte in Mittel- und Osteuropa. Die Musik der Religionsgemeinschaften um 1900. Lipsko, 5.-6. listopadu 2004

    Czech Academy of Sciences Publication Activity Database

    Freemanová, Michaela

    2004-01-01

    Roč. 30, č. 4 (2004), s. 647-648 ISSN 1335-2458. [Konferenz Stadtmusikgeschichte in Mittel- und Osteuropa. Die Musik der Religionsgemeinschaften um 1900. Leipzig, 04.11.05-04.11.06] Institutional research plan: CEZ:AV0Z9058907 Keywords : music * religious community * 19th century Subject RIV: AL - Art, Architecture, Cultural Heritage

  3. Value of MRI in the diagnosis of stress urinary incontinence in the absence of organ descent; Beitrag der MRT in der Diagnostik der Stress-Harninkontinenz ohne begleitenden Descensus urogenitalis

    Energy Technology Data Exchange (ETDEWEB)

    Beyersdorff, D.; Taupitz, M.; Fischer, T.; Hamm, B. [Humboldt-Univ., Berlin (Germany). Inst. fuer Radiologie; Tunn, R.; Rieprich, M. [Humboldt-Univ., Berlin (Germany). Klinik fuer Gynaekologie und Geburtshilfe

    2001-07-01

    To detect pathomorphological changes of the pelvic floor, the vagina, and the urethra by MR imaging in patients with stress urinary incontinence in the absence of organ descent compared with findings in 10 healthy controls. Materials and Methods: The study included 10 healthy controls and 38 patients with stage II urinary incontinence showing no urge symptoms but a pathological stress profile on urodynamic testing. The subjects underwent MR imaging with a phased-array coil at 1.5 T in addition to urodynamic testing and gynecological examination. The following sequences were used: axial and coronal PD-weighted TSE sequences with a FOV of 20 cm and a section thickness of 4 mm; axial STIR sequence. Sagittal T{sub 2}-weighted HASTE sequences were acquired during pelvic floor contraction, relaxation, and straining maneuvers. Results: In 22/38 cases pathomorphological changes were found by MR imaging. The pathomorphological changes were classified as lateral defects (n = 14) if the musculofascial connection between the levator muscle and the lateral vaginal wall or the butterfly shape of the vagina was absent and as central (n = 16) if changes were detected in the urethral wall. Defects of the pelvic floor muscles were detected in 8 cases. No underlying changes were identified in 16/38 cases. Conclusion: In cases of female urinary incontinence, MR imaging of the pelvic floor can detect pathomorphological changes, which are difficult to identify by clinical examination. MR imaging currently does not allow the detection of morphological changes in all forms of female urinary stress incontinence. (orig.) [German] In einer prospektiven Studie sollen mittels MRT pathomorphologische Veraenderungen des Beckenbodens, der Vagina und der Urethra bei Patientinnen mit Stress-Harninkontinenz (HI) ohne begleitenden Descensus urogenitalis im Vergleich zu Patientinnen ohne HI untersucht werden. Material und Methoden: 38 Patientinnen mit Stress-HI im Stadium II wurden zusaetzlich zur

  4. MR-guided biopsies of undetermined liver lesions: technique and results; MRT-gezielte perkutane Biopsie bei unklaren fokalen Leberlaesionen: Technik und Ergebnisse

    Energy Technology Data Exchange (ETDEWEB)

    Zangos, S.; Kiefl, D.; Eichler, K.; Engelmann, K.; Heller, M.; Herzog, C.; Mack, M.G.; Jacobi, V.; Vogl, T.J. [Inst. fuer Diagnostische und Interventionelle Radiologie, Johann-Wolfgang-Goethe-Univ. Frankfurt (Germany)

    2003-05-01

    Purpose: To evaluate safety and precision of liver tumor biopsies performed in an open low field system using different sequence techniques. Materials and Methods: In 47 patients with liver tumors, MR-guided biopsies were performed in a low field system (0.2 Tesla, Magnetom Open, Siemens) using two different sequences. The procedure was monitored with T1-weighted FLASH sequences (TR/TE = 100/9; 70 ) in all patients and with FISP-Rotated-Keyhole-sequence (TR/TE = 18/8; 90 ) in additional 20 patients. After positioning of the needle tip in the tumors, 166 biopsy specimens were acquired with 16 G cutting needles (Somatex{sup *}). The diameter of the biopsied lesions ranged from 1 to 10 cm (mean diameter 3.2 cm). Visibility of the needles and precision of the biopsies were evaluated. Results: All interventional biopsies were performed without vascular or organ injuries. Adequate specimens for histologic interpretation were obtained in 42 cases (89.3%). The biopsy results were non-specific in 2 patients (4.2%) and the lesions missed in 3 patients (6.3%). Mean in-room time was 35 minutes and the intervention time was 8.3 minutes. T1-weighted FLASH images proved optimal for confirming needle-tip placement during the biopsies or punctures. Organs, tumors and vessels were easily identified. The FISP sequence proved to be inferior in visualizing vessels and tumors. Conclusion: MR-guided liver biopsies are safely and precisely performed using T1-weighted FLASH-sequences with sufficient visualization of the lesions and might be complementary to US- or CT-guided biopsies. (orig.) [German] Zielsetzung: Evaluierung der Sicherheit und Genauigkeit MRT-gezielter Leberbiopsien unter Verwendung verschiedener Sequenzen. Methoden: Bei 47 Patienten mit unklaren Leberlaesionen wurden in einem offenen 0,2-Tesla-MR-System (Magnetom Open, Siemens) bildgesteuerte Biopsien unter Verwendung von zwei verschiedenen Sequenzen durchgefuehrt. Die Bildgebung erfolgte bei allen Patienten mittels T

  5. Quantitatively evaluated dynamic MRT in rheumatoid arthritis of the knee joint

    International Nuclear Information System (INIS)

    Koenig, H.; Bolze, X.; Wolf, K.J.; Sieper, J.

    1992-01-01

    32 patients with chronic polyarthritis were examined by MRT. Following intra-articular application of 25 mg prednisolon, 18 patients were reexamined after two of three weeks and 7 out of 18 patients were re-examined after 8 to 16 weeks, both by MRT and clinically. After an initial double echo sequence, we carried out a dynamic series of FLASH measurements (TR 30, TE 10 ms, 70deg) following an intravenous bolus of 0.1 mmol gadolinium-DTPA. Single intensity-time curves were treated quantitatively in relation to the pannus, muscles and effusions. Two or three weeks after treatment the curve parameters showed a reduction in pannus vascularisation which remained constant for the 8 to 16 weeks of further observation. Contrast diffusion in the pannus is initially reduced but approaches the early measurements at the time of the second examination. (orig.) [de

  6. 3D Simulation of Self-Compacting Concrete Flow Based on MRT-LBM

    Directory of Open Access Journals (Sweden)

    Liu-Chao Qiu

    2018-01-01

    Full Text Available A three-dimensional multiple-relaxation-time lattice Boltzmann method (MRT-LBM with a D3Q27 discrete velocity model is applied for simulation of self-compacting concrete (SCC flows. In the present study, the SCC is assumed as a non-Newtonian fluid, and a modified Herschel–Bulkley model is used as constitutive mode. The mass tracking algorithm was used for modeling the liquid-gas interface. Two numerical examples of the slump test and enhanced L-box test were performed, and the calculated results are compared with available experiments in literatures. The numerical results demonstrate the capability of the proposed MRT-LBM in modeling of self-compacting concrete flows.

  7. Uterine cervical cancer. Preoperative staging with magnetic resonance imaging; Zervixkarzinom. Praeoperatives Staging mittels Magnetresonanztomographie

    Energy Technology Data Exchange (ETDEWEB)

    Collettini, F.; Hamm, B. [Charite-Universitaetsmedizin Berlin, Campus Charite Mitte, Klinik fuer Radiologie, Berlin (Germany)

    2011-07-15

    The treatment of uterine cervical carcinoma is largely dependent on the tumor stage. Despite significant inaccuracies in the clinical examination, uterine cervical cancer remains the only gynecological form of cancer still largely staged according to clinical findings. Although imaging is still not included in the staging the recently published revised FIGO (Federation International de Gynecologie et d'Obstetrique) system encourages the use of modern cross-sectional imaging (magnetic resonance imaging MRI and computed tomography CT). Due to its high soft tissue contrast MRI allows excellent non-invasive assessment of the cervix with direct tumor delineation as well as assessment of the prognosis based on morphological factors. Studies in the literature report an accuracy of 93% for MRI in the preoperative assessment of tumor size and in the differentiation of operable from advanced cervical cancer. Therefore MRI is considered to be the optimal modality for diagnostic evaluation starting from FIGO stage IB1, for radiation therapy planning, and for exclusion of recurrence in follow-up. In this paper we give an overview of the role of magnetic resonance imaging in preoperative staging of uterine cervical cancer. (orig.) [German] Die Therapieplanung beim Zervixkarzinom ist weitgehend von der Stadieneinteilung nach FIGO (Federation International de Gynecologie et d'Obstetrique) abhaengig, die trotz erheblicher Ungenauigkeiten bei der klinischen Stadieneinteilung weiterhin aufgrund klinischer Untersuchungsbefunde erfolgt. Obwohl bildgebende Verfahren nach wie vor fuer die Stadieneinteilung nicht vorgesehen sind, wird im kuerzlich erschienen revidierten Stagingsystem der FIGO zum ersten Mal die Verwendung moderner Schnittbilddiagnostik (MRT und CT) befuerwortet. Die MRT ermoeglicht dank ihres hohen Weichteilkontrasts ein ausgezeichnetes nichtinvasives Staging des Zervixkarzinoms mit direkter Tumordarstellung sowie einer Prognoseabschaetzung anhand

  8. Haemophilic arthropathy of the knee. Gd-DTPA enhanced MRT. Clinical and radiological correlation; Haemophile Arthropathie des Kniegelenkes. Gd-DTPA-verstaerkte MRT: klinische und roentgenologische Korrelation

    Energy Technology Data Exchange (ETDEWEB)

    Naegele, M. [Radiologische Universitaetsklinik, Bonn (Germany); Kunze, V. [Radiologische Universitaetsklinik, Bonn (Germany); Hamann, M. [Radiologische Universitaetsklinik, Bonn (Germany); Eickhoff, H. [Orthopaedische Klinik, Krankenhaus Troisdorf (Germany); Koch, W. [Orthopaedische Klinik, Krankenhaus Troisdorf (Germany); Oldenburg, J. [Inst. fuer Experimentelle Haematologie und Transfusionsmedizin, Bonn (Germany); Reiser, M. [Muenchen Univ. (Germany). Inst. fuer Radiologische Diagnostik; Steudel, A. [Radiologische Universitaetsklinik, Bonn (Germany)

    1994-02-01

    17 patients with hemophilic arthropathy of the knee joint were studied with static and dynamic MRT before and after i.v. bolus injection of Gadolinium-DTPA (0,1 mmol/kg body weight). After contrast enhancement, synovial proliferations exhibited an increase of signal intensity (SI) of FFE and SE images of 47.7% and 37.4% respectively, whereas muscle and fatty tissue, tendons, bone marrow and joint effusion revealed only minor increase in SI. The gradient of signal intensity (ratio SI/time) of pannus was 39,6% min. Gd-DTPA enhanced MRI studies delineate and quantify the synovial proliferations in hemophilic arthropathy. Dynamic studies in hemophilic arthropathy do not provide qualitative assessment of the inflammatory process. (orig.) [Deutsch] Es wurden 17 Patienten mit einer haemophilen Arthropathie der Kniegelenke mit der statischen und dynamischen MRT vor und nach i.v. Bolusgabe von Gadolinium-DTPA (0,1 mmol/kg KG) untersucht. Nach Kontrastmittelgabe konnte ein Anstieg der Signalintensitaet des Pannus von 37,4% auf SE- und von 47,7% auf FFE-Aufnahmen gemessen werden. Der Gradient des Signalintensitaetsanstieges (%/Zeit) lag fuer Pannus bei 39,6%/min. Die Kontrastmittelgabe steigerte die Abgrenzbarkeit des Pannus von Gelenkerguss und den Gelenkbinnenstrukturen. Begleitend durchgefuehrte klinische und roentgenologische Bewertungen des Schweregrades der Arthropathie korrelierten nicht mit dem Signalintensitaetsverhalten des Pannus nach Kontrastmittelgabe. (orig.)

  9. Grundwassermodellbildung – Hydrostratigraphische Bewertungen mittels GCI-PetroKf, Datenbank- und Geoinformationssystemen

    DEFF Research Database (Denmark)

    Koch, Alexander; Fuchs, Sven; Göbel, Patricia

    reimportiert und für die Verwendung in Geoinformationssystemen (i.e. ArcGIS) weiter aufbereitet. Über Interpolationsverfahren konnte innerhalb des Programmes ArcGIS ein lateraler Bezug zwischen den verschiedenen Mächtigkeiten hergestellt werden, um so auf weitere Inhomogenitäten im Aufbau des Grundwasserleiter......-Systems schließen zu können. Anschließend wurden mittels ArcGIS die Quartärbasis des Modellraums konstruiert, sowie Grundwasserisolinien- und Grundwasserdifferenzenkarten berechnet. Die Grundwasserdifferenzenkarten reproduzieren gut die Grundwasserabsenkungen im Bereich von lokalen Tagebauen. Insgesamt zeigen sich...... gute Übereinstimmungen mit früheren hydrogeologischen Untersuchungen im Projektgebiet. Die Kombination des PetroKf-Algorithmus mit der Aufbereitung in einer Datenbank, sowie der Weiterverarbeitung in ArcGIS, zeigt einen praktikablen Weg zur Entwicklung und Parametrisierung eines hydrogeologischen...

  10. MRT in differentiation between tumour and implant material in the postoperative sella

    International Nuclear Information System (INIS)

    Kaiser, W.A.; Steckelbroeck, V.; Siewert, B.; Layer, G.; Hochstetter, A.; Reiser, M.

    1993-01-01

    MRT criteria have been developed to distinguish between tumour and implant material following examination of 50 patients who had transsphenoidal hypophysectomies for tumours. Judgements were based on the postoperative hormonal status and the operation notes. Following contrast injection of Gd-DTPA and using T 1 weighted spin-echo sequences, implant material appeared as sandwich-like, linear or circular structures. Residual recurrent tumour produced homogenous or non-homogenous aspects without marginal enhancement in 84% of cases. Postoperative displacement of the infundibulum to the opposite side was observed in 73% of patients with tumour remnants. Sensitivity of MRT was 70%, specificity 95%. There was a positive predictive value of 94% and a negative predictive value of 72% with an accuracy of 81%. This provides assistance in differentiating between tumour remnants and implant material. MRT is recommended as a method of examination for hypophyseal tumours to evaluate the success of surgery and where there is clinical doubt concerning residual or recurrent tumour. (orig.) [de

  11. Benign diseases of the mandible in MRI; Benigne Erkrankungen des Unterkiefers im MRT

    Energy Technology Data Exchange (ETDEWEB)

    Kress, B.; Sartor, K. [Universitaetsklinikum Heidelberg (Germany). Abt. Neuroradiologie; Gottschalk, A. [Bundeswehrkrankenhaus, Ulm (Germany). Abt. fuer Radiologie; Schmitter, M. [Universitaetsklinikum Heidelberg (Germany). Abt. fuer Zahnaerztliche Prothetik

    2004-04-01

    Diseases of the mandible affect the soft tissues aside from the osseous manifestation. This can be shown clearly and in great detail by magnetic resonance imaging (MRI). MRI is the gold standard in the diagnostic evaluation of any internal derangement of the temporomandibular joint. Dental MRI requires high resolution techniques and in some cases also intravenous administration of contrast material. These techniques allow delineation of the neurovascular bundle. In the past few years new indications were formulated, for example, the evaluation of the integrity of the inferior alveolar nerve in trauma and in radicular cysts. New quantitative methods now enable insights into the pathophysiology. The objective of this review is to communicate accepted indications for MRI of the mandible and to present innovative applications. (orig.) [German] Mandibulaere Erkrankungen beteiligen neben dem Knochen Weichteilstrukturen, die sich mit der MRT klar und detailreich darstellen lassen. In der bildgebenden Diagnostik der Binnenstoerung des Kiefergelenks (internal derangement) gilt die MRT als Goldstandard. Die MR-Tomographie des Unterkiefers erfordert hochaufloesende Techniken und bei besonderen Indikationen die intravenoese Kontrastmittelgabe. Diese Techniken erlauben es, das neurovaskulaere Buendel des Unterkiefers darzustellen. In den letzten Jahren sind neue Indikationsgebiete hinzugekommen, darunter solche, die die Unversehrtheit des N.alveolaris inferior bei Frakturen oder Raumforderungen des Unterkiefers ueberpruefen. Neue quantitative Verfahren geben mittlerweile Einblicke in Pathophysiologie. Ziel dieser Uebersichtsarbeit soll es sein, klassische Indikationen der Unterkiefer-MRT darzustellen und innovative Anwendungsmoeglichkeiten aufzuzeigen. (orig.)

  12. Applications of cerebral MRI in neonatology; MRT bei Neugeborenen mit Verdacht auf zerebrale Stoerung

    Energy Technology Data Exchange (ETDEWEB)

    Prayer, D. [Universitaetsklinik fuer Radiodiagnostik, Wien (Austria). Abt. fuer Neuroradiologie; Kuhle, S. [Universitaetsklinik fuer Kinder- und Jugendheilkunde, Wien (Austria). Abt. fuer Neonatologie, angeborene Stoerungen und Intensivmedizin; Blaicher, W. [Abt. fuer Frauenheilkunde und Praenatale Diagnostik, Wien (Germany)

    2000-01-01

    Magnetic resonance tomography (MRT) has become the most important method in the workup of infantile cerebral complications after primary sonography. Cerebral MR examination and image interpretation during the infantile period require extensive knowledge of morphological manifestations, their pathophysiological background, and frequency. The choice of imaging parameters and image interpretation is demonstrated in infarctions and hemorrhages of the mature and immature brain. A review of the main differential diagnoses is also given. The relevance of MR spectroscopy and fetal MRI is discussed. (orig.) [German] Zur Abklaerung zerebraler Veraenderungen bei Neugeborenen hat sich die Magnetresonanztomographie (MRT) als wichtigste weiterfuehrende Methode nach der Sonographie entwickelt. Die Durchfuehrung und Auswertung der MR-Untersuchungen erfordern jedoch eine genaue Kenntnis der morphologischen Manifestation, des pathophysiologischen Hintergrunds und der Haeufigkeit bestimmter zerebraler Komplikationen in diesem Lebensalter. Resuemee: Ausgehend von zerebrovaskulaeren Erkrankungen werden diese Fragen behandelt, wobei sowohl auf die Auswahl der adaequaten Untersuchungsparameter als auch auf die Bildinterpretation und die wichtigsten Differentialdiagnosen eingegangen wird. Die Bedeutung von MR-Spektroskopie und fetaler MRT wird diskutiert. (orig.)

  13. Clinical application of functional MRI for chronic epilepsy; Klinischer Einsatz der funktionellen MRT bei chronischer Epilepsie

    Energy Technology Data Exchange (ETDEWEB)

    Woermann, F.G.; Labudda, K. [Krankenhaus Mara, Epilepsiezentrum Bethel, Abteilung fuer Magentresonanztomographie, Bielefeld (Germany)

    2010-02-15

    Functional magnetic resonance imaging (fMRI) is frequently used in the presurgical diagnostic procedure of epilepsy patients, in particular for lateralization of speech and memory and for localization of the primary motor cortex to delineate the epileptogenic lesion from eloquent brain areas. fMRI is one of the non-invasive procedures in the presurgical diagnostic process, together with medical history, seizure semiology, neurological examination, interictal and ictal EEG, structural MRI, video EEG monitoring and neuropsychology. This diagnostic sequence leads either to the decision for or against elective epilepsy surgery or to the decision to proceed with invasive diagnostic techniques (Wada test, intra-operative or extra-operative cortical stimulation). It is difficult to evaluate the contribution of the fMRI test in isolation to the validity of the entire diagnostic sequence. Complications such as memory loss and aphasia in temporal lobe resections or paresis after frontal lobe resections are rare and rarely of disastrous extent. This further complicates the evaluation of the clinical relevance of fMRI as a predictive tool. In this article studies which investigated the concordance between fMRI and other diagnostic gold standards will be presented as well as the association between presurgical fMRI and postsurgical morbidity. (orig.) [German] Die funktionelle Magnetresonanztomographie (fMRT) wird im Rahmen der Epilepsiediagnostik vor epilepsiechirurgischen Eingriffen insbesondere zur Lateralisation von Sprache und Gedaechtnis und zur Lokalisation der Zentralregion eingesetzt, um den eloquenten Kortex von der epilepsieverursachenden, chirurgisch zugaenglichen Laesion abzugrenzen. Dabei ist die fMRT Teil einer Sequenz nichtinvasiver klinischer Tests (Anamnese, Anfall-Semiologie, neurologischer Status, interiktales und iktales EEG, strukturelles MRT, Video-EEG-Monitoring, Neuropsychologie). Das Ergebnis dieser Sequenz ist die Entscheidung fuer oder gegen einen

  14. Prognostic value of cardiovascular MRI in diabetics; Prognostischer Wert der kardiovaskulaeren MRT bei Diabetikern

    Energy Technology Data Exchange (ETDEWEB)

    Schlett, C.L.; Bertheau, R.C.; Kauczor, H.U.; Weckbach, S. [Universitaetsklinikum Heidelberg, Klinik fuer Diagnostische und Interventionelle Radiologie, Heidelberg (Germany)

    2015-04-01

    Risikostratifizierung von Noeten ist. Die klinische Untersuchung und die Bestimmung von Blutwerten dienen bei Diabetikern typischerweise zur Risikostratifizierung bzgl. kardio(zerebro)vaskulaerer Ereignisse in der Zukunft. Sowohl die Kardio- als auch die Ganzkoerper-MRT stellen standardisierte Verfahren in der klinischen Diagnostik dar. Deren Stellenwert bei der Vorhersage von Ereignissen mit entsprechender Risikostratifizierung bei Diabetikern gewinnt basierend auf aktuellen Studienergebnissen zunehmend an Bedeutung. Late Gadolinium Enhancement (LGE) im Kardio-MRT detektiert bei bis zu 30 % der Diabetiker stumme Myokardischaemien, die mit einer Hazard Ratio von 3-6 mit kardiovaskulaeren Ereignissen assoziiert sind. Ebenfalls zeigen linksventrikulaere Wandbewegungsstoerungen sowie eine erniedrigte Ejektionsfraktion einen prognostischen Wert. Im Ganzkoerper-MRT sind der Vessel-Score und Karotisstenosen zusaetzliche Praediktoren fuer kardio(zerebro)vaskulaere Ereignisse. Die MRT-basierte Vorhersage kardio(zerebro)vaskulaerer Ereignisse bietet einen signifikanten Mehrwert zur klassischen Risikostratifizierung bei Diabetikern. Jedoch erlaubt nur die umfassende Ganzkoerper-MRT-Untersuchung Patienten zu identifizieren, die ueber einen Zeitraum von 6 Jahren komplett frei von kardio(zerebro)vaskulaeren Ereignissen bleiben. Die Kardio-MRT, insbesondere die Erfassung von LGE, empfiehlt sich fuer die Vorhersage von Ereignissen. Die Ganzkoerper-MRT stellt einen prognostischen Mehrwert dar, deren klinische Relevanz in weiteren Studien geklaert werden muss. (orig.)

  15. MRI of interstitial lung diseases. What is possible?; MRT bei interstitiellen Lungenerkrankungen. Was ist moeglich

    Energy Technology Data Exchange (ETDEWEB)

    Biederer, J. [Kreisklinik Gross-Gerau, Radiologie Darmstadt, Gross-Gerau (Germany); Universitaetsklinikum Heidelberg, Klinik fuer Diagnostische und Interventionelle Radiologie, Heidelberg (Germany); Deutsches Zentrum fuer Lungenforschung (DZL), Translational Lung Research Center (TLRC) Heidelberg, Heidelberg (Germany); Thoraxklinik, Universitaetsklinikum Heidelberg, Klinik fuer Diagnostische und Interventionelle Radiologie mit Nuklearmedizin, Heidelberg (Germany); Wielpuetz, M.O.; Jobst, B.J.; Dinkel, J. [Universitaetsklinikum Heidelberg, Klinik fuer Diagnostische und Interventionelle Radiologie, Heidelberg (Germany); Deutsches Zentrum fuer Lungenforschung (DZL), Translational Lung Research Center (TLRC) Heidelberg, Heidelberg (Germany); Thoraxklinik, Universitaetsklinikum Heidelberg, Klinik fuer Diagnostische und Interventionelle Radiologie mit Nuklearmedizin, Heidelberg (Germany)

    2014-12-15

    Magnetic resonance imaging (MRI) of the lungs is becoming increasingly appreciated as a third diagnostic imaging modality besides chest x-ray and computed tomography (CT). Its value is well acknowledged for pediatric patients or for scientific use particularly when radiation exposure should be strictly avoided. However, the diagnosis of interstitial lung disease is the biggest challenge of all indications. The objective of this article is a summary of the current state of the art for diagnostic MRI of interstitial lung diseases. This article reflects the results of a current search of the literature and discusses them against the background of the authors own experience with lung MRI. Due to its lower spatial resolution and a higher susceptibility to artefacts MRI does not achieve the sensitivity of CT for the detection of small details for pattern recognition (e.g. fine reticulation and micronodules) but larger details (e.g. coarse fibrosis and honeycombing) can be clearly visualized. Moreover, it could be shown that MRI has the capability to add clinically valuable information on regional lung function (e.g. ventilation, perfusion and mechanical properties) and inflammation with native signal and contrast dynamics. In its present state MRI can be used for comprehensive cardiopulmonary imaging in patients with sarcoidosis or for follow-up of lung fibrosis after initial correlation with CT. Far more indications are expected when the capabilities of MRI for the assessment of regional lung function and activity of inflammation can be transferred into robust protocols for clinical use. (orig.) [German] Die MRT der Lunge entwickelt sich zu einer ernstzunehmenden dritten Saeule der Thoraxdiagnostik neben dem Thoraxroentgen und der Computertomographie (CT). Ihr Wert in der paediatrischen Lungendiagnostik oder fuer den wissenschaftlichen Einsatz, insbesondere wenn eine Strahlenexposition vermieden werden soll, ist unbestritten. Von allen Indikationen stellt die Diagnostik

  16. Aneurysmatic dissection of an aberrant right subclavian artery; Disseziierendes Aneurysma einer aberranten Arteria subclavia dextra: Diagnose mittels Ultrafast-CT

    Energy Technology Data Exchange (ETDEWEB)

    Reittner, P. [Universitaetsklinik fuer Radiologie, Graz (Austria). Abt. fuer Allgemeine Radiologie; Stacher, R. [Universitaetsklinik fuer Radiologie, Graz (Austria). Abt. fuer Allgemeine Radiologie

    1996-01-01

    Diagnosis with Ultrafast-CT: An aneurysm of an aberrant right subclavian artery is a very rare cause for dysphagia. We describe such a case in a 67-year-old patient, diagnosed with Ultrafast-CT and discuss it together in concert with the embryology and the radiological findings. (orig.) [Deutsch] Eine aberrierende Arteria subclavia dextra ist eine seltene Ursache fuer Dysphagie. Anhand eines 67jaehrigen Patienten werden Embryologie und radiologische Charakteristika, diagnostiziert mittels Ultrafast-CT, diskutiert. (orig.)

  17. Preoperative mapping of speech-eloquent areas with functional magnetic resonance imaging (fMRI): comparison of different task designs; Praeoperatives Mapping der Sprachareale mittels funktioneller Magnetresonanztomographie (fMRT) bei Patienten mit Hirntumoren: Ein Paradigmenvergleich

    Energy Technology Data Exchange (ETDEWEB)

    Prothmann, S.; Zimmer, C. [Leipzig Univ. (Germany). Abt. fuer Neuroradiologie; Puccini, S.; Dalitz, B.; Kuehn, A.; Kahn, T. [Leipzig Univ. (Germany). Klinik und Poliklinik fuer Diagnostische Radiologie; Roedel, L. [Leipzig Univ. (Germany). Klinik und Poliklinik fuer Neurochirurgie

    2005-11-15

    Purpose: Functional magnetic resonance imaging (fMRI) is a well-established, non-invasive method for pre-operative mapping of speech-eloquent areas. This investigation tests three simple paradigms to evaluate speech lateralisation and visualisation of speech-eloquent areas. Materials and Methods: 14 healthy volunteers and 16 brain tumour patients were given three tasks: to enumerate months in the correct order (EM), to generate verbs fitting to a given noun (GV) and to generate words fitting to a given alphabetic character (GW). We used a blocked design with 80 measurements which consisted of 4 intervals of speech activation alternating with relaxation periods. The data were analysed on the basis of the general linear model using Brainvoyager {sup registered}. The activated clusters in the inferior frontal (Broca) and the posterior temporal (Wernicke) cortex were analysed and the laterality indices calculated. Results: In both groups the paradigms GV and GW activated the Broca's area very robustly. Visualisation of the Wernicke's area was best achieved by the paradigm GV. The paradigm EM did not reliably stimulate either the frontal or the temporal cortex. Frontal lateralisation was best determined by GW and GV, temporal lateralisation by GV. Conclusion: The paradigms GV and GW visualise two essential aspects of speech processing: semantic word processing and word production. In a clinical setting with brain tumour patients, both, GV and GW can be used to visualise frontal and temporal speech areas, and to determine speech dominance. (orig.)

  18. Health co-benefits in mortality avoidance from implementation of the mass rapid transit (MRT) system in Kuala Lumpur, Malaysia.

    Science.gov (United States)

    Kwan, Soo Chen; Tainio, Marko; Woodcock, James; Hashim, Jamal Hisham

    2016-03-01

    The mass rapid transit (MRT) is the largest transport infrastructure project under the national key economic area (NKEA) in Malaysia. As urban rail is anticipated to be the future spine of public transport network in the Greater Kuala Lumpur city, it is important to mainstream climate change mitigation and public health benefits in the local transport development. This study quantifies the health co-benefits in terms of mortality among the urbanites when the first line of the 150 km MRT system in Kuala Lumpur commences by 2017. Using comparative health risk assessment, we estimated the potential health co-benefits from the establishment of the MRT system. We estimated the reduced CO2 emissions and air pollution (PM2.5) exposure reduction among the general population from the reduced use of motorized vehicles. Mortality avoided from traffic incidents involving motorcycles and passenger cars, and from increased physical activity from walking while using the MRT system was also estimated. A total of 363,130 tonnes of CO2 emissions could be reduced annually from the modal shift from cars and motorcycles to the MRT system. Atmospheric PM2.5 concentration could be reduced 0.61 μg/m3 annually (2%). This could avoid a total of 12 deaths, mostly from cardio-respiratory diseases among the city residents. For traffic injuries, 37 deaths could be avoided annually from motorcycle and passenger cars accidents especially among the younger age categories (aged 15-30). One additional death was attributed to pedestrian walking. The additional daily physical activity to access the MRT system could avoid 21 deaths among its riders. Most of the mortality avoided comes from cardiovascular diseases. Overall, a total of 70 deaths could be avoided annually among both the general population and the MRT users in the city. The implementation of the MRT system in Greater Kuala Lumpur could bring substantial health co-benefits to both the general population and the MRT users mainly from the

  19. MRI in cardiac sarcoidosis and amyloidosis; MRT bei kardialer Sarkoidose und Amyloidose

    Energy Technology Data Exchange (ETDEWEB)

    Bauner, K.U. [Klinikum der Ludwig-Maximilians-Universitaet Muenchen, Campus Grosshadern, Institut fuer Klinische Radiologie, Muenchen (Germany); Wintersperger, B. [Klinikum der Ludwig-Maximilians-Universitaet Muenchen, Campus Grosshadern, Institut fuer Klinische Radiologie, Muenchen (Germany); University of Toronto, Department of Medical Imaging, Toronto General Hospital, Toronto, ON (Canada)

    2013-01-15

    Sarcoidosis and amyloidosis are both multisystem disorders, which may involve the heart; however, isolated cardiac disease is rare. Diagnosis of cardiac sarcoidosis and amyloidosis is crucial because the patient prognosis is dependent on cardiac involvement and early treatment. Echocardiography is the first line imaging modality in the diagnostic work-up of both diseases, possibly giving hints towards the correct diagnosis. Besides myocardial biopsy and radionuclide studies cardiac magnetic resonance imaging (MRI) is routinely performed in patients suspect of having infiltrative cardiomyopathy. The T1 mapping procedure is currently being evaluated as a new technique for detection and quantification of global myocardial enhancement, as seen in cardiac amyloidosis. Sensitivities and specificities for detection of cardiac sarcoidosis and amyloidosis can be significantly improved by MRI, especially with late gadolinium enhancement (LGE) imaging. In cardiac sarcoidosis the use of LGE is outcome-related while in amyloidosis analysis of T1-mapping may be of prognostic value. If cardiac involvement in sarcoidosis or amyloidosis is suspected cardiac MRI including LGE should be performed for establishing the diagnosis. (orig.) [German] Die Sarkoidose und Amyloidose sind Multisystemerkrankungen, in deren Verlauf es zu einer kardialen Beteiligung kommen kann. Bildgebend wird als primaeres Verfahren die Echokardiographie eingesetzt. Zur weiteren Diagnostik wird neben der Biopsie und nuklearmedizinischen Verfahren v. a. die MRT herangezogen. Als neuere Technik zur Darstellung globaler diffuser Kontrastmittelanreicherungen, wie sie im Rahmen der Amyloidose vorkommen, wird z. Z. das T1-Mapping evaluiert. Durch den Einsatz der MRT, insbesondere des Late-Gadolinium-Enhancements (LGE), koennen die Sensitivitaet und Spezifitaet in der Diagnostik der kardialen Sarkoidose und Amyloidose entscheidend verbessert werden. Bei der Sarkoidose stellt das Vorhandensein eines LGE einen

  20. Magnetic resonance tomography and ultrasound in rheumatology; MRT und Sonographie in der Rheumatologie

    Energy Technology Data Exchange (ETDEWEB)

    Kainberger, F. [Universitaetsklinik fuer Radiodiagnostik, Ludwig-Boltzmann-Inst. fuer Physikalische und Radiologische Tumordiagnostik, Wien (Austria); Czerny, C. [Universitaetsklinik fuer Radiodiagnostik, Ludwig-Boltzmann-Inst. fuer Physikalische und Radiologische Tumordiagnostik, Wien (Austria); Trattnig, S. [Universitaetsklinik fuer Radiodiagnostik, Ludwig-Boltzmann-Inst. fuer Physikalische und Radiologische Tumordiagnostik, Wien (Austria); Lack, W. [Universitaetsklinik fuer Orthopaedie, Wien (Austria); Machold, K. [Universitaetsklinik fuer Innere Medizin III, Wien (Austria). Abt. fuer Rheumatologie; Graninger, W. [Universitaetsklinik fuer Innere Medizin III, Wien (Austria). Abt. fuer Rheumatologie

    1996-08-01

    Technical innovations and software improvements in magnetic resonance imaging (MRI) and high-resolution sonography (US) have definitely influenced the diagnostic imaging of rheumatic diseases. For MRI, improvements in surface coils, dedicated low-field systems (0.2 T), and software improvements (shorter acquisition times and refinements of fat suppressing techniques) must be mentioned. For sonography, the main innovations concern the development of higher transducer frequencies (7-15 Mhz) and power Doppler imaging. Clinical evaluations have shown that MRI and US are most useful in cases of suspected rheumatic disease with negative plain film radiographs and for documenting the course of the disease, diagnosing of early rheumatoid arthritis, making a differential diagnosis in clinically unclear rheumatic diseases, investigating vascularization, and quantifying pannus formation. In order to improve diagnostic efficacy the role of MRI and US in the management of patients with rheumatic disease should be reconsidered. (orig.) [Deutsch] Technische Innovationen in Hard- und Software von Magnetresonanztomographie (MRT) und Sonographiegeraeten haben die bildgebende Diagnostik in der Rheumatologie massgeblich beeinflusst (Verbesserungen der Oberflaechenspulen mit hohen Gradientenfeldern, dedizierte Niederfeldgeraete, Softwareverbesserungen in Form von kuerzeren Aquisitionszeiten und Verfeinerungen in der Fettunterdrueckung, hoehere Transducerfrequenzen zwischen 7 und 15 Mhz, Powerdopplerverfahren). Fuer die klinische Anwendung bedeutet dies, dass MRT und Sonographie als bildgebende Zusatzverfahren nach der Anfertigung konventioneller Roentgenaufnahmen anzuwenden sind, wenn diese unauffaellige Resultate ergeben oder spezielle Fragen zur Schwere des Krankheitsprozesses bzw. von Folgeerscheinungen zu beantworten sind. Im besonderen betrifft dies den Nachweis der Frueharthritis, die Differentialdiagnose klinisch nicht klar einzuordnender Krankheitsbilder und die Bestimmung des

  1. Synthese von analogen Filtern auf einer rekonfigurierbaren Hardware-Architektur mittels eines Genetischen Algorithmus

    Directory of Open Access Journals (Sweden)

    S. Trendelenburg

    2008-05-01

    Full Text Available Rekonfigurierbare Analog-Arrays (FPAAs sind der Versuch, die Vorteile der aus der digitalen Welt bekannten FPGAs (Flexibilität, Entwurfsgeschwindigkeit auch für analoge Anwendungen verfügbar zu machen. Aufgrund der Vielfalt der analogen Schaltungstechnik ist die Abbildung von vorgegebenen Schaltungskonzepten auf eine FPAA-Architektur nicht immer einfach lösbar.

    Diese Arbeit stellt einen neuen Ansatz für die Synthese von Filtern auf einer FPAA-Architektur für zeitkontinuierliche Analogfilter mittels eines Genetischen Algorithmus (GA vor. Anhand eines Matlab-Modells des FPAA, das eine gute übereinstimmung mit Simulationen des FPAA auf Transistorebene aufweist, wurde gezeigt, dass eine große Vielzahl verschiedener Filterstrukturen auf dieser Architektur dargestellt werden kann. Daraufhin wurde ein Genetischer Algorithmus entwickelt, der es erlaubt, aus einer gegebenen Filterspezifikation Konfigurationsdatensätze zu synthetisieren, die den gewünschten Filter auf die FPAA-Architektur abbilden.

  2. NMR imaging of the vertebral column and the spinal canal. 2. rev. and enl. ed.; MRT der Wirbelsaeule und des Spinalkanals

    Energy Technology Data Exchange (ETDEWEB)

    Forsting, Michael [Universitaetsklinikum Essen (Germany). Inst. fuer Diagnostische und Interventionelle Radiologie und Neuroradiologie; Uhlenbrock, Detlev [St.-Josefs-Hospital, Dortmund (Germany). MVZ Radiologie, Nuklearmedizin und Strahlentherapie; Wanke, Isabel [Privatklinikengruppe Hirslanden, Zurich (Switzerland); Universitaetsklinikum Essen (Germany). Inst. fuer Diagnostische und Interventionelle Radiologie und Neuroradiologie

    2009-07-01

    The book on the MRT (magnetic resonance tomography) of the vertebral cord and spinal canal covers the following topics: physics fundamentals and application; malformation of the spinal canal; degenerative vertebral column diseases; vertebral column and spinal canal carcinomas; inflammatory diseases of the vertebral column and the spinal canal; applicability of MRT in case of acute spinal cord traumata; vascular diseases of the spinal canal.

  3. Acquired CNS lesions in fetal MRI; Erworbene ZNS-Laesionen im fetalen MRT

    Energy Technology Data Exchange (ETDEWEB)

    Reith, W.; Pogledic, I. [Universitaetsklinikum des Saarlandes, Homburg/Saar, Klinik fuer Diagnostische und Interventionelle Neuroradiologie, Homburg/Saar (Germany)

    2013-02-15

    Acquired central nervous system (CNS) lesions are often subtle; therefore, the prenatal diagnosis of these lesions is extremely important. The fetal ultrasound examination and magnetic resonance imaging (MRI) are two important imaging methods that give an insight into these types lesions. The method of choice during pregnancy is still fetal ultrasound; however, fetal MRI is important when there are certain pathologies, e.g. periventricular leukomalacia (PVL) or malformations of the vein of Galen. In this manner clinicians can plan further therapy after childbirth in advance (e.g. cerebral angiography or embolization). (orig.) [German] Die erworbenen ZNS-Laesionen sind oft subtil, und eine praezise praenatale Diagnostik ist in diesen Faellen besonders wichtig. Die fetale Sonographie und das fetale MRT koennen hierzu einen relevanten Beitrag leisten. Die Sonographie ist immer noch die Untersuchungsmethode der Wahl waehrend der Schwangerschaft. Insbesondere bei bestimmten Pathologien wie der periventrikulaeren Leukomalazie (PVL) oder einer V. -Galeni-Malformation ist das fetale MRT sehr hilfreich, um nach der Geburt die entsprechenden weitergehenden Massnahmen, wie eine zerebrale Angiographie und Embolisation, fruehzeitig zu planen. (orig.)

  4. Signal effects of various radiographic contrast media and their interaction with gadolinium DTPA during MRT

    International Nuclear Information System (INIS)

    Kopka, L.; Funke, M.; Fischer, U.; Vosshenrich, R.; Schroeder, M.; Grabbe, E.

    1994-01-01

    T 1 and T 2 weighted signals dereived from various radiological contrast media were studied during MRT spin-echo sequences. In addition, the interaction between radiological contrast media and Gadolinium-DTPA concerning T 1 signals was evaluated. Ionic (ioxitalaminic acid) and non-ionic radiological contrast media (Iopromid, Iotrolan) were used in diagnostic concentrations. Measurements were carried out with a superconductive magnet of 1.5 Tesla. Radiological contrast media produced significantly higher signals than a physiological sodium chloride solution in T 1 -weighted spin-echo sequences. Evn small amounts (15% of total volume) of radiological contrast media during T 1 -weighted spin-echo sequences led to a significant reduction (about 25%) of the signal intensity of a 2 mM Gadolinium-DTPA solution. This may lead to diagnostic problems, as was shown in a series of 25 MR arthrograms of the shoulder. It is recommended than an interval of at least 6 hours should elapse between the use of a radiological contrst medium and an MRT examination. (orig.) [de

  5. MRI methods for pulmonary ventilation and perfusion imaging; Methoden der MRT zur Ventilations- und Perfusionsbildgebung der Lunge

    Energy Technology Data Exchange (ETDEWEB)

    Sommer, G. [Universitaetsspital Basel, Klinik fuer Radiologie und Nuklearmedizin, Basel (Switzerland); Bauman, G. [Universitaetsspital Basel, Klinik fuer Radiologie und Nuklearmedizin - Radiologische Physik, Basel (Switzerland)

    2016-02-15

    Detektion frueher pathologischer Veraenderungen. Standardverfahren der bildgebenden Lungendiagnostik sind die Computertomographie (CT) zur morphologischen Darstellung und die Perfusions-/Ventilationsszintigraphie bzw. ''single photon emission computed tomography'' (SPECT) zur funktionellen Diagnostik. Zur Darstellung der Lungenventilation stehen die MRT mit hyperpolarisierten Gasen, die O{sub 2}-verstaerkte MRT, die MRT mit fluorierten Gasen und die Fourier-Dekompositions-MRT (FD-MRT) zur Verfuegung. Zur Perfusionsbestimmung koennen die dynamische kontrastmittelverstaerkte MRT (DCE-MRT), das ''arterial spin labeling'' (ASL) und die FD-MRT verwendet werden. Bildgebende Verfahren erlauben einen genaueren Einblick in die Pathophysiologie der Lungenfunktion auf regionaler Ebene. Vorteile der MRT sind die fehlende Strahlenbelastung, welche die schonende Akquisition dynamischer Daten ermoeglicht sowie die Vielfalt der verfuegbaren Kontraste und damit zugaenglichen Parameter der Lungenfunktion. Ausreichende klinische Daten existieren nur fuer bestimmte Anwendungen der DCE-MRT. Fuer die uebrigen Verfahren gibt es lediglich Machbarkeitsstudien und Fallserien mit unterschiedlichem Umfang. Hyperpolarisierte Gase sind technisch bedingt nur eingeschraenkt in der Klinik anwendbar. Ein klinischer Einsatz der genannten Verfahren sollte mit Ausnahme der DCE-MRT nur innerhalb von Studien erfolgen. (orig.)

  6. Altheim geothermal plant. Power generation by means of an ORC turbogenerator; Geothermieanlagen Altheim. Stromerzeugung mittels Organic-Rankine-Cycle Turbogenerator

    Energy Technology Data Exchange (ETDEWEB)

    Pernecker, G [Marktgemeindeamt Altheim (Austria)

    1997-12-01

    The report describes the project of the Austrian market town of Altheim to generate electricity by means of an ORC turbogenerator using low-temperature thermal water. The project is to improve the technical and economic situation of the existing industrial-scale geothermal project. (orig.) [Deutsch] Der Bericht beschreibt das Vorhaben der Marktgemeinde Altheim in Oberoesterreich, Strom mittels eines Organic-Rankine-Cycle-Turbogenerators unter Verwendung niedrig temperierten Thermalwassers zu produzieren. Ziel bzw. der Zweck des Projektes ist es, die technische und wirtschaftliche Situation der bestehenden Grossthermieanlage zu verbessern. (orig.)

  7. MR imaging in congenital complicated anterior body wall defects; MRT von komplizierten angeborenen Bauchwanddefekten

    Energy Technology Data Exchange (ETDEWEB)

    Hoermann, M.; Scharitzer, M. [Universitaetsklinik fuer Radiodiagnostik, AKH-Wien (Austria); Pumberger, W. [Universitaetsklinik fuer Kinderchirurgie, AKH-Wien (Austria); Patzak, B. [Pathologisch-anatomisches Museum im Narrenturm, AKH-Wien (Austria)

    2003-04-01

    Introduction: Aim of this study was to estimate the value of postmortem MR imaging in evaluation of specimen with congenital anterior body wall defects of the museum of pathologic-anatomy. Material and Methods: We examined 19 specimen with a 1.5 Tesla unit by using T{sub 1}- and T{sub 2}-weighted sagittal and coronal sequences. In some specimen additional axial T{sub 2}-weighted images were obtained. We evaluated the site of the bowel, the liver, the heart and presence of associated disorders. Results: The bowels were completely intraabdominal, in two specimen, completely extraabdominal in 12 specimen and in 5 specimen intra- and extraabdominal. The liver was in two specimen completely extraabdominal/in 12 completely intracorporal, and in 5 specimen intra- and extraabdominal. In 5 cases the heart was located extraanatomically. In 12 specimen we found disorders of the spine and the extremities. Congenital disorders of the kidneys were found in 6 specimen. Conclusion: MR imaging is of great value in the assessment of congenital anterior body wall defects. In the light of ultrafast sequences the role of fetal MR imaging in the evaluation of congenital body wall defects may be mandatory in the future. (orig.) [German] Einleitung: Wir nutzten die Sammlung des pathologisch-anatomischen Museums in Wien, um die Wertigkeit der MRT zur Beschreibung von angeborenen vorderen Bauchwanddefekten und deren assoziierten Erkrankungen zu bestimmen. Material und Methode: Wir untersuchten 19 Exponate mit einem 1,5-Tesla-Geraet unter Verwendung von sagittalen und koronalen T{sub 1}- und T{sub 2}-gewichteten Sequenzen. Ausgewertet wurden die Lage des Darmes, der Leber, des Herzens und assoziierte Missbildungen. Ergebnisse: Der Darm lag in zwei Faellen intraabdominal, zur Gaenze extraabdominal in 12 Faellen, intra- und extraabdominal in 5 Faellen. Die Leber war in zwei Exponaten zur Gaenze extraabdominal, in 5 intra- und extraabdominal und in 12 Exponaten intraabdominal. Assoziiert waren

  8. Creutzfeldt-Jakob disease: the value of MRI; Creutzfeldt-Jakob-Krankheit: Stellenwert der MRT

    Energy Technology Data Exchange (ETDEWEB)

    Urbach, H.; Tschampa, H.J.; Keller, E.; Schild, H.H. [Radiologische Klinik, Neuroradiologie, Rheinische Friedrich-Wilhelms-Univ. Bonn (Germany); Paus, S. [Neurologische Klinik, Rheinische Friedrich-Wilhelms-Univ. Bonn (Germany)

    2001-06-01

    To define the role of MRI in the diagnosis of Creutzfeldt-Jakob disease (CJD). Methods: 14 patients with suspected CJD were studied within 3 years. MRI findings were correlated with WHO established diagnostic criteria (clinical findings, EEG, CSF with 14-3-3 protein assay). Results: 12 patients had CJD. One patient each suffered from Hashimoto's encephalitis and ALS dementia complex, respectively. Nine of 12 CJD patients had increased signal intensity of the striatum (n = 8), pulvinar thalami (n = 5) and/or cerebellar and cerebral cortex (n = 3), respectively. Signal intensity was most pronounced on FLAIR sequences; six patients were studied with diffusion-weighted MRI and showed impaired diffusion in these areas. Both patients without CJD did not show the abovementioned signal changes (sensitivity 75%, specificity and positive predictive value 100%, respectively). Conclusion: If patients with suspected CJD are studied with FLAIR and diffusion-weighted sequences, this disorder can reliably be proven or ruled out. Typical MRI findings narrow down the differential diagnosis and should be included in the WHO diagnostic criteria. (orig.) [German] Bestimmung des Stellenwerts der MRT in der Diagnostik der Creutzfeldt-Jakob-Krankheit (CJK). Methoden: Analyse der MRTs von 14 innerhalb von drei Jahren mit Verdacht auf CJK zugewiesenen Patienten. Korrelation der MRTs mit den entsprechend den WHO-Diagnosekriterien etablierten Untersuchungsverfahren (Klinik, EEG, Liquor mit 14-3-3 Protein-Nachweis). Ergebnisse: 12 Patienten hatten eine CJK, jeweils ein Patient hatte eine Hashimoto-Enzephalitis bzw. einen ALS-Demenz-Komplex. Bei 9 der 12 CJK-Patienten fanden sich beidseits Signalerhoehungen des Striatum (n = 8), des Pulvinar thalami (n = 5) und/oder des Kleinhirn- bzw. Grosshirnkortex (n = 3). Die Signalerhoehungen waren am deutlichsten auf FLAIR-Aufnahmen erkennbar; 6 mit diffusionsgewichteter MRT untersuchte Patienten wiesen eine eingeschraenkte Diffusion dieser Areale

  9. Magnetic resonance imaging in the evaluation of pneumonia; Nachweis von pneumonischen Infiltraten mit der MRT

    Energy Technology Data Exchange (ETDEWEB)

    Eibel, R.; Herzog, P.; Dietrich, O.; Reiser, M.; Schoenberg, S.O. [Ludwig-Maximilians-Universitaet Muenchen (Germany). Institut fuer Klinische Radiologie; Rieger, C.; Ostermann, H. [Ludwig-Maximilians-Universitaet Muenchen (Germany). Abteilung fuer Haematologie/Onkologie, Klinikum Grosshadern

    2006-04-15

    Magnetic resonance imaging (MRI) of the lung is challenging because of substantial drawbacks. However, lung pathologies that are associated with increased attenuation values in CT enhance visualization in MRI: proton density is increased and tissue-air interfaces, resulting in susceptibility artifacts, are reduced in pneumonia, pneumonitis, edema, and carcinoma. On the other hand, many lung diseases result in shortness of breath, so that patients cannot hold their breath for long periods. Therefore, fast imaging techniques are required which should also allow for high spatial resolution so that small lesions can be detected. Calcifications and air pockets within lesions are not readily recognized with MRI. Thin section CT is standard for the diagnosis of pneumonia. With parallel imaging techniques, MRI examination of the lungs can be performed with short periods of breath holding, which allow for sub-centimeter resolution in the z-axis. Especially for follow-up examinations in immunocompromised patients and, in some instances, for the staging of malignant diseases (malignant pleural mesothelioma, lung cancer, respectively), MRI is very promising and may contribute to a decrease in the radiation exposure of the patients. (orig.) [German] Die MRT des Lungenparenchyms ist wegen des extrem niedrigen Protonengehalts des Lungengewebes und den starken Grenzflaechen zwischen Luft und Parenchym prinzipiell sehr problematisch. Allerdings liegt bei pathologischen Lungengewebeveraenderungen eine andere Situation vor, da infolge von Oedem, Entzuendung bzw. Tumorwachstum der Protonengehalt erhoeht und die Grenzflaechen reduziert sind. Viele Erkrankungen der Lunge fuehren dazu, dass der Patient den Atem nicht lange anzuhalten vermag. Daher sind MRT-Pulssequenzen erforderlich, die eine Datenakquisition in wenigen Sekunden gestatten. Aus technischer Sicht werden die vom CT bekannten Submillimeterschichten vielleicht nie realisierbar sein, sodass sicher auch in Zukunft kleine

  10. Possibilities of whole-body MRI for investigating musculoskeletal diseases; Moeglichkeiten der Ganzkoerper-MRT zur Diagnostik muskuloskelettaler Erkrankungen

    Energy Technology Data Exchange (ETDEWEB)

    Lenk, S.; Claussen, C.D.; Schlemmer, H.P. [Klinikum der Eberhardt-Karls-Universitaet Tuebingen, Abteilung fuer Diagnostische Radiologie (Germany); Fischer, S. [Universitaetsklinikum Tuebingen, Abteilung fuer Strahlentherapie (Germany); Koetter, I. [Universitaetsklinikum Tuebingen, Abteilung fuer Haematoonkologie (Germany)

    2004-09-01

    This contribution outlines possibilities and limitations of whole-body MRI for investigating musculoskeletal diseases. Benefits and drawbacks of the novel whole-body MRI technology are discussed and a possible whole-body MRI sequence protocol for musculoskeletal examinations is proposed. Muscle, joint and bone diseases are discussed in which the application of whole-body MRI may be of advantage. Particularly, polymyositis, muscledystrophy, rheumatoid arthritis, spondylitis ancylosans, multiple trauma, skeletal metastases, multiple myeloma and malignant lymphoma are mentioned. Whole-body MRI opens new advantages for the examination of multifocal musculoskeletal diseases. The clinical benefit of this method for particular diseases has to be evaluated in further studies, however. (orig.) [German] Dieser Beitrag gibt eine Uebersicht ueber die Moeglichkeiten und Limitationen der Ganzkoerper-MRT fuer die Diagnostik von Erkrankungen des muskuloskelettalen Systems. Es werden die Vor- und Nachteile der Ganzkoerper-MRT eroertert und ein Sequenzprotokoll fuer die muskuloskelettale Diagnostik vorgeschlagen. Auf Muskel-, Gelenk- und Knochenerkrankungen, bei denen der Einsatz der Ganzkoerper-MRT indiziert erscheint, dabei insbesondere Polymyositis, Muskeldystrophie, rheumatoide Arthritis, Spondylitis ankylosans, Polytrauma, Skelettmetastasen, Plasmozytom und das maligne Lymphom wird eingegangen. Die Ganzkoerper-MRT bietet neue Moeglichkeiten, insbesondere zur Ausbreitungsdiagnostik und Verlaufskontrolle multifokaler muskuloskelettaler Erkrankungen. Der klinische Nutzen dieser Methode fuer die einzelnen Erkrankungsentitaeten muss in weiteren Studien evaluiert werden. (orig.)

  11. The technique of MRT aided abdominal drainage using an open low field magnet. Feasibility and first results

    International Nuclear Information System (INIS)

    Gehl, H.B.; Frahm, C.; Schimmelpenning, H.; Weiss, H.D.

    1996-01-01

    To test the practicality of MRT-aided drainage using an open low field magnet and to report on the early clinical results. So far seven patients have been treated (four subphrenic abscesses, two psoas abscesses and one pancreatic pseudocyst). The planning of the approach and catheter insertion were carried out under MRT control (Magnetom Open, 0.2 T). Subsequent treatment was controlled by CT and fluoroscopy. Initial puncture was carried out with a non-magnetic 18 gauge Chiba needle. The drainage catheter was introduced by Seldinger's technique in six cases and with a trocar in one patient. In all seven patients drainage could be started successfully. The design of the magnet and coils permitted adequate accessibility of the patient. There were no problems in visualising the puncture needle. Controlling the position of the catheter by MRT was, however, difficult. The first two steps in abscess drainage (planning the approach and inserting the catheter) can be carried out under MRT control. For further catheter control and observing the course of the disease we presently prefer CT or fluoroscopy. (orig.) [de

  12. New procedures. Comprehensive staging of lung cancer by MRI; Neue Verfahren. Umfassendes Staging des Lungenkarzinoms mit der MRT

    Energy Technology Data Exchange (ETDEWEB)

    Hintze, C. [Universitaetsklinikum Schleswig-Holstein, Campus Kiel, Klinik fuer Diagnostische Radiologie, Kiel (Germany); Deutsches Krebsforschungszentrum (DKFZ) Heidelberg, Abteilung Radiologie (E010), Heidelberg (Germany); Dinkel, J. [Deutsches Krebsforschungszentrum (DKFZ) Heidelberg, Abteilung Radiologie (E010), Heidelberg (Germany); Biederer, J. [Universitaetsklinikum Schleswig-Holstein, Campus Kiel, Klinik fuer Diagnostische Radiologie, Kiel (Germany); Heussel, C.P. [Thoraxklinik Heidelberg, Abteilung Diagnostische und Interventionelle Radiologie, Heidelberg (Germany); Puderbach, M. [Deutsches Krebsforschungszentrum (DKFZ) Heidelberg, Abteilung Radiologie (E010), Heidelberg (Germany); Thoraxklinik Heidelberg, Abteilung Diagnostische und Interventionelle Radiologie, Heidelberg (Germany)

    2010-08-15

    Lung cancer staging according to the TNM system is based on morphological assessment of the primary cancer, lymph nodes and metastases. All aspects of this important oncological classification are measurable with MRI. Pulmonary nodules can be detected at the clinically relevant size of 4-5 mm in diameter. The extent of mediastinal, hilar and supraclavicular lymph node affection can be assessed at the same time. The predominant metastatic spread to the adrenal glands and spine can be detected in coronal orientation during dedicated MRI of the lungs. Search focused whole body MRI completes the staging. Various additional MR imaging techniques provide further functional and clinically relevant information during a single examination. In the oncological context the most important techniques are imaging of perfusion and tumor motion. Functional MRI of the lungs complements the pure staging and improves surgical approaches and radiotherapy planning. (orig.) [German] Das Staging des Lungenkarzinoms nach dem TNM-System basiert auf der morphologischen Einschaetzung des Primarius, der Lymphknoten und Metastasen. Alle Aspekte dieser onkologisch wichtigen Beurteilung lassen sich mit der MRT erfassen. Pulmonale Rundherde sind ab der klinisch relevanten Groesse von 4-5 mm Durchmesser sicher erkennbar. Die Groesse der mediastinalen, hilaeren und supraklavikulaeren Lymphknoten kann in einem Untersuchungsgang bestimmt werden. In der koronaren Schichtfuehrung der dedizierten MRT der Lunge werden die Bereiche der bevorzugten Metastasierung in Nebennieren und weite Teile der Wirbelsaeule miterfasst. Durch eine gezielte Ganzkoerper-MRT als Suchmethode wird der letzte Teil des Stagings erfuellt. Die MRT bietet vielfaeltige Moeglichkeiten, zusaetzliche funktionelle, klinisch relevante Informationen innerhalb einer Untersuchung zu erheben. Im onkologischen Kontext sind die Perfusionsbildgebung der Lunge und die Bewegungsabschaetzung der Tumoren am bedeutendsten. Die funktionelle MRT der

  13. Haemophilic arthropathy of the knee. Gd-DTPA enhanced MRT. Clinical and radiological correlation

    International Nuclear Information System (INIS)

    Naegele, M.; Kunze, V.; Hamann, M.; Eickhoff, H.; Koch, W.; Oldenburg, J.; Reiser, M.

    1994-01-01

    17 patients with hemophilic arthropathy of the knee joint were studied with static and dynamic MRT before and after i.v. bolus injection of Gadolinium-DTPA (0,1 mmol/kg body weight). After contrast enhancement, synovial proliferations exhibited an increase of signal intensity (SI) of FFE and SE images of 47.7% and 37.4% respectively, whereas muscle and fatty tissue, tendons, bone marrow and joint effusion revealed only minor increase in SI. The gradient of signal intensity (ratio SI/time) of pannus was 39,6% min. Gd-DTPA enhanced MRI studies delineate and quantify the synovial proliferations in hemophilic arthropathy. Dynamic studies in hemophilic arthropathy do not provide qualitative assessment of the inflammatory process. (orig.) [de

  14. Errors during MRT measurements of the left ventricular volume using a multi-slice technique

    International Nuclear Information System (INIS)

    Pitton, M.B.; Just, M.; Grebe, P.; Kreitner, K.F.; Erbel, R.; Thelen, M.

    1992-01-01

    A multi-slice technique for MRT measurements of the left ventricular volume is much faster than the use of single-slice methods and is therefore better tolerated, leaving time for additional measurements. The end-diastolic left ventricular volume can be reliably measured by this method (123.3±13.5 ml vs. 124.1±ml). The end-systolic volume is consistently overestimated by 23.7±18,3% compared with the reference value obtained by single slice measurements (47.9±8.9 ml vs 39.1±7.9 ml). Correspondingly, stroke volume and ejection fraction is underestimated on average by 10.6±9.7% and 10.6±7.6% respectively). (orig.) [de

  15. Diagnosis of cerebral metastases by means of standard doses of Gadobutrol versus a high-dose protocol. Intraindividual evaluation of a phase-II high-dose study; Zerebrale Metastasendiagnostik mittels Standarddosis Gadobutrol vs. einem Hochdosisprotokoll. Intraindividuelle Evaluierung einer Phase-II-Hochdosisstudie

    Energy Technology Data Exchange (ETDEWEB)

    Vogl, T.J. [Strahlen- und Poliklinik, Universitaetsklinikum Rudolf Virchow, Freie Univ. Berlin (Germany); Friebe, C.E. [Strahlen- und Poliklinik, Universitaetsklinikum Rudolf Virchow, Freie Univ. Berlin (Germany); Balzer, T. [Schering AG, Berlin (Germany); Mack, M.G. [Strahlen- und Poliklinik, Universitaetsklinikum Rudolf Virchow, Freie Univ. Berlin (Germany); Steiner, S. [Strahlen- und Poliklinik, Universitaetsklinikum Rudolf Virchow, Freie Univ. Berlin (Germany); Schedel, H. [Strahlen- und Poliklinik, Universitaetsklinikum Rudolf Virchow, Freie Univ. Berlin (Germany); Pegios, W. [Strahlen- und Poliklinik, Universitaetsklinikum Rudolf Virchow, Freie Univ. Berlin (Germany); Lanksch, W. [Neurologische Klinik, Universitaetsklinikum Rudolf Virchow, Freie Univ. Berlin (Germany); Banzer, D. [Behring Krankenhaus, Berlin (Germany); Felix, R. [Strahlen- und Poliklinik, Universitaetsklinikum Rudolf Virchow, Freie Univ. Berlin (Germany)

    1995-08-01

    In a clinical phase-II study 20 patients who had been diagnosed as having brain metastases with CT or MRT were studied prospectively with Gadobutrol, a new nonionic, low osmolality contrast agent. Each patient received an initial injection of 0.1 mmol/kg body weight and an additional dose of 0.2 mmol/kg Gadobutrol 10 min later. Spinecho images were obtained before and after the two applications of Gadobutrol. Dynamic scanning (Turbo-FLASH) was performed for 3 min after each injection of the contrast agent. Both quantitative and qualitative data were intraindividually evaluated. The primary tumor was a bronchial carcinoma in 11 cases; in 9 other cases there were different primary tumors. Forty-eight hours after the use of Gadobutrol there were no adverse signs in the clinical examination, vital signs or blood and urine chemistry. Statistical analysis (Friedman test and Wilcoxon test) of the C/N ratios between tumor and white matter, percentage enhancement, and visual assessment rating revealed statistically significant superiority of high-dose Gadobutrol injection in comparison to the standard dose. The percentage enhancement increased on average from 104% after 0.1 mmol/kg to 162% after 0.3 mmol/kg Gadobutrol. Qualitative delineation and contrast of the lesions increased significantly. The use of high-dose Gadobutrol improved the detection of 36 additional lesions in 6 patients. (orig./VHE) [Deutsch] In einer Phase-II-Studie wurden 20 Patienten mit zerebralen Metastasen eines Primaertumors ausserhalb des ZNS mit dem nichtionischen, paramagnetischen Kontrastmittel Gadobutrol magnetresonanztomographisch untersucht. T1- und T2-gewichtete Nativsequenzen und T1-gewichtete Postkontrastsequenzen wurden gemessen nach einer Dosis von 0,1 mmol/kg KG und nach einer additiven Dosis von 0,2 mmol/kg KG Gadobutrol 10 min nach Erstinjektion. Mittels Turbo-FLASH-Sequenzen wurde die Dynamik der Konstrastmittelanreicherung gemessen. Die klinischen und laborchemischen Untersuchungen

  16. Detection of liver lesions with gadolinium-enhanced VIBE sequence in comparison with SPIO-enhanced MRI; Detektion von Leberlaesionen mit der Gadolinium-verstaerkten VIBE-Sequenz im Vergleich zur SPIO-verstaerkten MRT

    Energy Technology Data Exchange (ETDEWEB)

    Heim, P.; Steiner, P.; Dieckmann, C.; Adam, G. [Universitaetsklinikum Hamburg-Eppendorf (Germany). Klinik und Poliklinik fuer Diagnostische und Interventionelle Radiologie; Schoder, V. [Universitaetsklinikum Hamburg-Eppendorf (Germany). Inst. fuer Medizinische Biometrie und Epidemiologie; Kuhlencordt, R. [Universitaetsklinikum Hamburg-Eppendorf (Germany). Klinik und Poliklinik fuer Allgemein-, Viszeral-, und Thoraxchirurgie

    2003-10-01

    Purpose: Detection of malignant liver lesions with gadolinium-enhanced volumetric interpolated breath-hold examination (VIBE) in comparison with SPIO-enhanced MRT (four different SPIO-enhanced T2w sequences) and histological and imaging follow-up in non-cirrhotic livers at 1.5 T. Patients and methods: Twenty-two patients with suspected focal liver lesions prospectively underwent a gadolinium-enhanced 3D VIBE. Four T2w sequences (HASTE sequence, fast spin-echo-sequence with and without fat-saturation, FLASH 2D gradient echo-sequence) after administration of superparamagnetic iron oxide (SPIO) served as gold standard combined with histological work-up in 17 patients and histological and imaging follow-up in five patients. The image quality was evaluated and the detectability of intrahepatic lesions was rated by the alternative free-response receiver operating characteristic (AFROC) analysis. In addition, the contrast-to-noise ration was compared. Results: Altogether 49 malignant and 35 benign liver lesions were found. Concerning the image quality, VIBE turned out to be of slightly poorer image quality than the SPIO-enhanced examination with HASTE sequence (4.95 vs. 5.0). The fast spin-echo-sequence without fat-saturation demonstrated the highest contrast-to-noise ratio. All sequences showed a comparable certainty in detecting lesion (area under the curve 0.68-0.74) and identifying malignant liver lesions. Conclusions: Despite the small number of patients, VIBE seems to be a comparable, inexpensive and fast method in diagnosing malignant liver lesions. (orig.) [German] Ziel: Detektion maligner Leberlaesionen mit der Gadolinium-verstaerkten 3D-Gradientenecho-Sequenz in Atemanhaltetechnik (VIBE-Sequenz) im Vergleich mit der SPIO-verstaerkten MRT (vier verschiedene SPIO-verstaerkte T2-gew. Sequenzen) sowie histologischen und bildgebenden (Verlaufs-) Untersuchungen in nicht-zirrhotischen Lebern bei 1,5 T. Patienten und Methoden: 22 Patienten mit Verdacht auf maligne

  17. The use of a cine-technique in the MRT investigation of the temporo-mandibular joint. Die Anwendung der 'Cine-Technik' in der MRT-Diagnostik des Kiefergelenkes

    Energy Technology Data Exchange (ETDEWEB)

    Vogl, T.J.; Assal, J. (Univ. Muenchen, Radiologische Klinik Innenstadt (Germany)); Eberhard, D.; Weigl, P.; Randzio, J. (Univ. Muenchen, Klinik und Poliklinik fuer Kieferchirurgie (Germany))

    1992-03-01

    A new cine-technique in a prospective study using rapid gradient echo sequences was evaluated for the MRT investigation of the temporo-mandibular joint. A newly developed hydraulic apparatus was used to produce progressive opening of the jaw and MRT appearances were recorded during predetermined points of mandibular movement. The investigation included 16 normals and 34 patients. A modified gradient echo sequence was combined with an optimised surface coil or a special double coil and this provided good spatial resolution of the articular disc and of the muscular and bony structure. Amongst the abnormal findings were luxation of the disc (15 cases), tears in the disc (5 cases), late effects of internal derangements (12 cases) and condylar hypermobility (7 cases). The new cine-technique provides specific images in any chosen position of the mandible depending on the clinical disability of the patient. (orig.).

  18. The use of a cine-technique in the MRT investigation of the temporo-mandibular joint

    International Nuclear Information System (INIS)

    Vogl, T.J.; Assal, J.; Eberhard, D.; Weigl, P.; Randzio, J.

    1992-01-01

    A new cine-technique in a prospective study using rapid gradient echo sequences was evaluated for the MRT investigation of the temporo-mandibular joint. A newly developed hydraulic apparatus was used to produce progressive opening of the jaw and MRT appearances were recorded during predetermined points of mandibular movement. The investigation included 16 normals and 34 patients. A modified gradient echo sequence was combined with an optimised surface coil or a special double coil and this provided good spatial resolution of the articular disc and of the muscular and bony structure. Amongst the abnormal findings were luxation of the disc (15 cases), tears in the disc (5 cases), late effects of internal derangements (12 cases) and condylar hypermobility (7 cases). The new cine-technique provides specific images in any chosen position of the mandible depending on the clinical disability of the patient. (orig.) [de

  19. Value of magnetic resonance imaging in diffuse liver diseases; Stellenwert der MRT bei diffusen Lebererkrankungen

    Energy Technology Data Exchange (ETDEWEB)

    Schramm, N.; D' Anastasi, M.; Reiser, M.F.; Zech, C.J. [Klinikum der Ludwig-Maximilians-Universitaet Muenchen, Campus Grosshadern, Institut fuer Klinische Radiologie, Muenchen (Germany)

    2012-08-15

    Diffuse liver diseases show an increasing prevalence. The diagnostic gold standard of liver biopsy has several disadvantages. There is a clinical demand for non-invasive imaging-based techniques to qualitatively and quantitatively evaluate the entire liver. Ultrasound, computed tomography (CT) and magnetic resonance imaging (MRI) are routinely used. Steatosis: chemical shift and frequency selective imaging, MR spectroscopy (MRS). Hemochromatosis: MR-based iron quantification. Fibrosis: MR elastography, diffusion, intravoxel incoherent motion (IVIM) and MR perfusion. T1-weighted in and opposed phase imaging is the clinically most frequently used MR technique to noninvasively detect and quantify steatosis. New methods for quantification that are not influenced by confounders like iron overload are under investigation. The most sensitive method to measure the fat content of the liver is MRS. As data acquisition and analysis remain complex and there is no whole organ coverage, MRS of the liver is not a routine method. With an optimized protocol incorporating T2* sequences, MRI is the modality of choice to quantify iron overload in hemochromatosis. Standard MR sequences cannot depict early stages of liver fibrosis. Advanced MR techniques (e.g. elastography, diffusion, IVIM and perfusion) for noninvasive assessment of liver fibrosis appear promising but their role has to be further investigated. (orig.) [German] Die Praevalenz diffuser Lebererkrankungen nimmt zu. Der klinische Goldstandard, die Leberbiopsie, hat zahlreiche Nachteile. Es besteht ein Bedarf an bildgebenden Verfahren zur nichtinvasiven qualitativen und quantitativen Beurteilung der gesamten Leber bei diesen Erkrankungen. Hier sind Ultraschall, CT und MRT zu nennen. Steatosis: Chemical-shift- und frequenzselektive Bildgebung, MR-Spektroskopie (MRS) zur Fettquantifizierung. Haemochromatose: MR-basierte Eisenquantifizierung. Fibrose: MR-Elastographie, Diffusion, ''intravoxel incoherent motion

  20. Combined PET/MRI in cerebral and paediatric diagnostics; Kombinierte PET/MRT-Diagnostik bei zerebralen und paediatrischen Fragestellungen

    Energy Technology Data Exchange (ETDEWEB)

    Pfluger, T.; Vollmar, C.; Porn, U.; Schmid, R.; Dresel, S.; Leinsinger, G.; Schmid, I.; Winkler, P.; Fischer, S.; Hahn, K. [Klinik und Poliklinik fuer Nuklearmedizin, Ludwig-Maximilians-Univ. Muenchen (Germany)

    2002-07-01

    The aim of this overview is presentation of MRI and PET as synergistic modalities for combined analysis of morphology and function. For operative planning in epilepsy surgery, definition of the epileptogenic focus based on functional PET diagnostics and morphological MRI is decisive. For staging and follow-up examinations in oncology, MRI should be complemented by PET for the assessment of tumor vitality. In paediatric oncology patients we could demonstrate a therapy relevant increase of sensitivity/specificity with combined PET/MRI in contrast to single modalities. In the brain, full spectrum of digital image registration and three-dimensional reconstruction should be used. In extracranial cases, image fusion is disturbing due to a partial loss of image information of single modalities by the fusion process. (orig.) [German] Ziel dieser Uebersicht ist die Darstellung der MRT und PET als synergistische Verfahren zur Analyse von Morphologie und Funktion. Zur Resektionsplanung im Rahmen der Epilepsiechirurgie ist die Definition des Epilepsiefokus anhand der funktionellen PET-Diagnostik und die exakte Kenntnis der zerebralen Morphologie aus der MRT ganz entscheidend. Im Rahmen des onkologischen Stagings und bei Verlaufskontrollen ist wegen der geringeren Spezifitaet der MRT die additive PET zur Beurteilung der Tumorvitalitaet erforderlich. Anhand eines paediatrisch-onkologischen Patientengutes konnten wir zeigen, dass mit der kombinierten PET/MRT-Diagnostik eine therapierelevante Steigerung der Sensitivitaet/Spezifitaet gegenueber den Einzeluntersuchungen moeglich ist. Bei zerebralen Fragestellungen sollte das gesamte Spektrum der digitalen Bildfusion mit direkter Ueberlagerung mehrerer Modalitaeten und anschliessender dreidimensionaler Rekonstruktion ausgeschoepft werden. Bei extrakraniellen Fragestellungen ist die direkte Bildueberlagerung eher hinderlich, da die Bildinformation der Einzelmodalitaeten durch die Fusion teilweise verloren geht. (orig.)

  1. MRT versus CT in the diagnosis of pneumonia. Evaluation of a T2-weighted utrafast turbo-spin-echo sequence (UTSE)

    International Nuclear Information System (INIS)

    Leutner, C.; Lutterbey, G.; Kuhl, C.K.; Flacke, S.; Schild, H.H.; Glasmacher, A.; Theisen, A.; Wardelmann, E.; Grohe, C.

    1999-01-01

    Purpose: To evaluate a T 2 -weighted URSE sequence for the assessment of pulmonary infiltrations in comparison to CT. Methods: 28 MRT scans of 22 patients with confirmed pneumonia were recorded on a 1.5 Tesla apparatus with an expiratory and diastolic triggered, T 2 -weighted ultrafast-spin-echo sequence in axial slice mode with the following parameters: TR eff /T E /Turbofactor 2000-4000/90 ms/21-23; slice thickness/separation 6/0.6 mm; FOV 360 mm; 24 slices. 24 spiral CTs (sice thickness/table advance: 1-2 mm/10 mm) were available for comparison. The separate evaluation of MRTs and CTs was performed by three radiologists in a consensus procedure with regard to pulmonary lesions (e.g., infiltration, round foci, net patterns) and image quality of the MRTs (4-step scale). Results: In 71% of the cases the CTs and MRTs agreed with the diagnosis and representation of the lesions, in 25% MRT was superior. MRT was better for the detection of pulmonary abscesses. In 93% the image quality of the MRT was very good to good. Conclusions: MRT in the technique presented here is in most cases equal to CT for the detection of pneumonia. Diagnosis of pulmonary abscesses seems to be better with MRT. (orig.) [de

  2. Magnetic resonance imaging of pulmonary perfusion. Technical requirements and diagnostic impact; MRT der Lungenperfusion. Technische Voraussetzungen und diagnostischer Stellenwert

    Energy Technology Data Exchange (ETDEWEB)

    Attenberger, U.I.; Buesing, K.; Schoenberg, S.O.; Fink, C. [Klinikum Mannheim der Universitaet Heidelberg, Institut fuer Klinische Radiologie und Nuklearmedizin, Universitaetsmedizin Mannheim, Mannheim (Germany); Ingrisch, M.; Reiser, M. [Klinikum der Ludwig-Maximilians-Universitaet Muenchen, Institut fuer Klinische Radiologie, Campus Grosshadern, Muenchen (Germany)

    2009-08-15

    With technical improvements in gradient hardware and the implementation of innovative k-space sampling techniques, such as parallel imaging, the feasibility of pulmonary perfusion MRI could be demonstrated in several studies. Dynamic contrast-enhanced 3D gradient echo sequences as used for time-resolved MR angiography have been established as the preferred pulse sequences for lung perfusion MRI. With these techniques perfusion of the entire lung can be visualized with a sufficiently high temporal and spatial resolution. In several trials in patients with acute pulmonary embolism, pulmonary hypertension and airway diseases, the clinical benefit and good correlation with perfusion scintigraphy have been demonstrated. The following review article describes the technical prerequisites, current post-processing techniques and the clinical indications for MR pulmonary perfusion imaging using MRI. (orig.) [German] Mit der Verfuegbarkeit leistungsfaehiger Gradientensysteme und schneller k-Raum-Akquisitionstechniken wie der parallelen Bildgebung konnten verschiedene Studien die Machbarkeit der Lungenperfusionsbildgebung in der MRT zeigen. In der Praxis haben sich dynamische kontrastverstaerkte 3D-Gradientenechosequenzen, wie sie fuer zeitaufgeloeste MR-Angiographien verwendet werden, fuer die Bildgebung der Lungenperfusion etabliert. Hiermit ist es moeglich, die Perfusion der gesamten Lunge mit ausreichend hoher zeitlicher und raeumlicher Aufloesung zu visualisieren. In mehren klinischen Studien konnte bei Patienten mit Lungenembolie, pulmonaler Hypertonie sowie Erkrankungen der Atemwege und des Lungenparenchyms der klinische Nutzen der Lungenperfusions-MRT und die gute Uebereinstimmung mit der Lungenperfusionsszintigraphie nachgewiesen werden. Der folgende Uebersichtsartikel beschreibt die technische Durchfuehrung, Bildnachverarbeitung und die klinischen Anwendungsgebiete der MRT zur Untersuchung der Lungenperfusion. (orig.)

  3. CT and MRI of the liver: when, what, why?; CT und MRT der Leber: wann, was, warum

    Energy Technology Data Exchange (ETDEWEB)

    Budjan, J.; Schoenberg, S.O.; Attenberger, U.I. [Medizinische Fakultaet Mannheim der Universitaet Heidelberg, Institut fuer Klinische Radiologie und Nuklearmedizin, Universitaetsmedizin Mannheim, Mannheim (Germany)

    2017-05-15

    The detection and differential diagnostic clarification of liver pathologies play an important role in almost all medical disciplines. Because of its superior soft tissue contrast, the availability of liver-specific contrast agents and functional techniques, magnetic resonance imaging (MRI) is the method of choice for the diagnostics of focal and diffuse liver pathologies. In addition to its superior detection and differentiation capabilities, MRI can provide prognostic information and enable early assessment of the therapy response for malignant liver lesions using functional techniques, especially diffusion imaging. Computed tomography (CT) is the imaging method of choice for the detection of traumatic liver injury. Despite the increasing availability of functional techniques in CT, MRI remains the overall modality of choice in liver imaging. (orig.) [German] Die Detektion und die differenzialdiagnostische Abklaerung von Leberpathologien spielen in nahezu allen medizinischen Disziplinen eine bedeutende Rolle. Ihre Vorteile in Hinblick auf Weichteilkontrast, die Verfuegbarkeit leberspezifischer Kontrastmittel und funktionelle Techniken machen die MRT zum bildgebenden Verfahren der Wahl fuer die gezielte Abklaerung fokaler oder diffuser Leberpathologien. Neben hoeheren Detektionsraten und besseren Differenzierungsmoeglichkeiten stehen in der MRT funktionelle Techniken - insbesondere die Diffusionsbildgebung - zur Verfuegung, die eine Prognoseabschaetzung und die fruehe Beurteilung von Therapieansprechen bei malignen Leberlaesionen erlauben. Die CT ist bei der Detektion traumatischer Leberverletzungen Bildgebungsverfahren der Wahl; trotz der auch in der CT zunehmend verfuegbaren funktionellen Techniken bleibt die MRT in der Leberbildgebung weiterhin ueberlegen. (orig.)

  4. Aorta cross-section calculation and 3D visualization from CT or MRT data using VRML

    Science.gov (United States)

    Grabner, Guenther; Modritsch, Robert; Stiegmaier, Wolfgang; Grasser, Simon; Klinger, Thomas

    2005-04-01

    Quantification of vessel diameters of artherosclerotic or congenital stenosis is very important for the diagnosis of vascular diseases. The aorta extraction and cross-section calculation is a software-based application that offers a three-dimensional, platform-independent, colorized visualization of the extracted aorta with augmented reality information of MRT or CT datasets. This project is based on different types of specialized image processing algorithms, dynamical particle filtering and complex mathematical equations. From this three-dimensional model a calculation of minimal cross sections is performed. In user specified distances, the aorta is cut in differently defined directions which are created through vectors with varying length. The extracted aorta and the derived minimal cross-sections are then rendered with the marching cube algorithm and represented together in a three-dimensional virtual reality with a very high degree of immersion. The aim of this study was to develop an imaging software that delivers cardiologists the possibility of (i) furnishing fast vascular diagnosis, (ii) getting precise diameter information, (iii) being able to process exact, local stenosis detection (iv) having permanent data storing and easy access to former datasets, and (v) reliable documentation of results in form of tables and graphical printouts.

  5. Advanced MRI techniques of the fetal brain; Zukunftsweisende MRT-Techniken des fetalen Gehirns

    Energy Technology Data Exchange (ETDEWEB)

    Schoepf, V.; Dittrich, E.; Berger-Kulemann, V.; Kasprian, G.; Kollndorfer, K.; Prayer, D. [Medizinische Universitaet Wien, Abteilung fuer Neuroradiologie und Muskuloskelettale Radiologie, Universitaetsklinik fuer Radiodiagnostik, Wien (Austria)

    2013-02-15

    Evaluation of the normal and pathological fetal brain. Magnetic resonance imaging (MRI). Advanced MRI of the fetal brain. Diffusion tensor imaging (DTI) is used in clinical practice, all other methods are used at a research level. Serving as standard methods in the future. Combined structural and functional data for all gestational ages will allow more specific insight into the developmental processes of the fetal brain. This gain of information will help provide a common understanding of complex spatial and temporal procedures of early morphological features and their impact on cognitive and sensory abilities. (orig.) [German] Evaluierung des gesunden bzw. pathologischen fetalen Gehirns. Die Magnetresonanztomographie. Zukunftsweisende Techniken in der MRT-Bildgebung des fetalen Gehirns. Die Diffusionstensorbildgebung (DTI) befindet sich bereits in der klinischen Anwendung, alle anderen Methoden sind bisher noch als experimentell zu werten. Auf dem Weg zur Etablierung als Standardverfahren. Eine kombinierte Verarbeitung funktioneller und struktureller Daten, modelliert fuer jede Schwangerschaftswoche, wird es zukuenftig ermoeglichen, anhand dieser fusionierten Informationen einen praezisen Einblick in den Entwicklungsprozess des Gehirns zu erlangen. Diese Erkenntnisse und Ergebnisse werden entscheidend zur Klaerung des zeitlichen Verlaufs und des komplexen Aufbaus frueher morphologischer Auffaelligkeiten beitragen sowie deren Einfluss auf kognitive und sensorische Faehigkeiten aufzeigen. (orig.)

  6. MRT-lattice Boltzmann computations of natural convection and volumetric radiation in a tilted square enclosure

    Energy Technology Data Exchange (ETDEWEB)

    Moufekkir, F.; Moussaoui, M.A.; Mezrhab, A. [Laboratoire de Mecanique and Energetique, Faculte des sciences, Departement de physique 60000 Oujda (Morocco); Lemonnier, D. [Institut Pprime, CNRS-ENSMA-Univ. Poitiers, ENSMA, BP 40109, 86961 Futuroscope Chasseneuil cedex (France); Naji, H. [Universite Lille Nord de France, F-59000 Lille (France); Laboratoire Genie Civil and geo-Environnement - LGCgE- EA 4515, UArtois/FSA Bethune, F-62400 Bethune (France)

    2012-04-15

    A numerical analysis is carried out for natural convection while in an asymmetrically heated square cavity containing an absorbing emitting medium. The numerical approach adopted uses a hybrid thermal lattice Boltzmann method (HTLBM) in which the mass and momentum conservation equations are solved by using multiple relaxation time (MRT) model and the energy equation is solved separately by using the finite difference method (FDM). In addition, the radiative transfer equation (RTE) is treated by the discrete ordinates method (DOM) using the S8 quadrature to evaluate the source term of the energy equation. The effects of parameters such as the Rayleigh number Ra, the optical thickness {tau} and the inclination angle {phi}, are studied numerically to assess their impact on the flow and temperature distribution. The results presented in terms of isotherms, streamlines and averaged Nusselt number, show that in the absence of the radiation, the temperature and the flow fields are centro-symmetric and the cavity core is thermally stratified. However, radiation causes an overall increase in temperature and velocity gradients along both thermally active walls

  7. MRI of esophagus. N staging and more...; MRT des Oesophagus. N-Staging und mehr...

    Energy Technology Data Exchange (ETDEWEB)

    Krupski-Berdien, G. [Krankenhaus Reinbek St.-Adolf- Stift, Abteilung fuer diagnostische und interventionelle Radiologie, Reinbek (Germany)

    2007-02-15

    Esophageal disease is common. Fluoroscopy with or without fast cine-sequences is able to depict swallowing dynamics precisely and therefore is used in cases with swallowing disturbance, achalasia or diverticula etc. It is performed in addition to primary endoscopy. There is no evidence based indication for MRI in these settings as it is not to rule out postsurgical fistula and incompetence. Endoscopy and endosonography are gold standard for the depiction as well as staging of esophageal tumors hence differentiation of the esophageal wall layers and detection of suspicious lymph nodes is possible. And from both, biopsies may be taken. New techniques as OCT (optical coherence tomography) can demonstrate in situ carcinoma and therefore helps to decide for limited treatments as mucosectomy. For today multimodular treatment strategies in esophageal carcinoma the T-stage will lead to the treatment decision whereas the nodal-stage will give information about the prognosis. As a matter of fact endoscopy is unable to pass a stenosis esophageal tumor in up to 50% of the cases and will therefore not be able to give precise information on both T- and N-stage resulting in a good indication for MRI. Fetal MRI of the chest is a new topic in which MRI seems to be superior to ultrasonography. (orig.) [German] Erkrankungen des Oesophagus sind haeufig. Die Durchleuchtungsuntersuchung, ggf. mit schnellen Cinesequenzen, vermag exakt die Dynamik des Schluckakts darzustellen und wird regelhaft bei Fragestellungen wie ''Verschlucken'' und ''Globusgefuehl'', Verdacht auf Achalsie etc. sowie bei der Suche nach Divertikeln eingesetzt und ergaenzt die primaere Endoskopie. Die MRT besitzt hier derzeit keinen gesicherten Stellenwert - ebenso wie bei der haeufigsten Indikation zur Oesophagus-Breischluck-Untersuchung in der Klinik, der Frage nach Paravasation und Fistelung nach oesophagogastralen Eingriffen. Die exakten Lokalisation eines Oesophagustumors

  8. In-depth investigation of escalator riding accidents in heavy capacity MRT stations.

    Science.gov (United States)

    Chi, Chia-Fen; Chang, Tin-Chang; Tsou, Chi-Lin

    2006-07-01

    In 2000, the accident rate for escalator riding was about 0.815 accidents per million passenger trips through Taipei Metro Rapid Transit (MRT) heavy capacity stations. In order to reduce the probability and severity of escalator riding accidents and enhance the safety of passengers, the Drury and Brill model [Drury, C.G., Brill, M., 1983. Human factors in consumer product accident investigation. Hum. Factors 25 (3), 329-342] for in-depth investigation was adopted to analyze the 194 escalator riding accidents in terms of victim, task, product and environment. Prevention measures have been developed based on the major causes of accidents and other related contributing factors. The results from the analysis indicated that the majority of the escalator riding accidents was caused by passengers' carrying out other tasks (38 cases, including carrying luggage 24 cases, looking after accompany persons 9 cases, and 5 others), loss of balance (26 cases, 13.4%), not holding the handrail (20 cases, 10.3%), unhealthy passengers (18 cases, 9.3%), followed by people struck by other passenger (16 cases, 8.2%). For female passengers aged 15-64 years, their rushing for trains accidents could have been prevented by wearing safer footwear or by appropriate signing being provided indicating the location and traveling direction of escalators. Female passengers aged 65 years and above whose accidents were caused by loss of balance, should be encouraged to take the elevator instead. To prevent entrapment injuries, following a stricter design code can be most effective. Further in-depth accident investigation is suggested to cover the activity of the victim prior to the accident, any involved product, the location of the accident on the escalator, any medical treatment, what went wrong, opinion of the respondent on the causes of the accident, and personal characteristics of the passengers. Also, management must trade off productivity and safety appropriately to prevent "Organizational

  9. Intraoperative appearance of the resection area in brain-tumor operations in an open 0,5 MRT; Intraoperatives Erscheinungsbild des Resektionsbereichs bei Hirntumoroperationen in einem offenen 0,5-T-MRT

    Energy Technology Data Exchange (ETDEWEB)

    Dietrich, J. [Universitaetsklinik fuer Diagnostische Radiologie, Leipzig (Germany). Arbeitsbereich Neuroradiologie; Schneider, J.P.; Schulz, T. [Universitaetsklinik fuer Diagnostische Radiologie, Leipzig (Germany); Seifert, V.; Trantakis, C. [Universitaetsklinik fuer Neurochirurgie, Leipzig (Germany); Kellermann, S. [Leipzig Univ. (Germany). Abt. fuer Neuropathologie

    1998-11-01

    During MRI-controlled resection of brain tumors using an open MRI system, operation-induced alterations may occur, especially enhancement of the resection cavity wall. This may simulate tumor areas, resulting in false assessment of the resection or resection of non-tumorous areas. Based on 42 MRI- and biopsy-controlled brain tumor resections in an 0.5 T open MRI (Signa SP, GE), the appearance and origin of operation-induced reactions are analyzed. In our opinion, there is a superposition of preformed peritumoral reactions by operation-induced microcontusions. The beginning of the cavity wall enhancement needs at least 10-15 min. MRI-controlled analysis of the intraoperative steps by the neurosurgeon and neuroradiologist allows discrimination of operation-induced reactions from tumor areas and leads to safe operation. (orig.) [Deutsch] Bei der intraoperativen Kontrolle von Hirntumorresektionen in offenen MRT-Geraeten kann es zu operativ induzierten Veraenderungen, insbesondere Rand-enhancement-Zonen, kommen. Diese koennen Tumorreste vortaeuschen, so dass die Radikalitaet des Eingriffs unterschaetzt wird oder nicht tumortragende Hirnareale entfernt werden. Ergebnisse und Diskussion: Anhand von 42 in einem offenen 0,5-T-MRT (Signa SP, GE) vorgenommenen, biopsiekontrollierten Hirntumoroperationen werden Erscheinungsbild und Entstehungsweise der Randveraenderungen analysiert. Bei den haeufig vorzufindenden Rand-enhancement-Zonen handelt es sich um eine Ueberlagerung von praeformierten Tumorrandreaktionen mit Mikrokontusionen. Die Ausbildung dieser Veraenderungen braucht eine Mindestzeit von 10-15 min. Die staendige Analyse der die Tumorresektion begleitenden MRT-Kontrollen durch den Operateur und einen mit der Problematik vertrauten Radiologen gestattet in der Regel die Differenzierung der operativ induzierten Veraenderungen und erhoeht damit die Sicherheit des Eingriffs. (orig.)

  10. Dental magnetic resonance tomography (dental-MRT) as a method for imaging of the maxillo-mandibular bone; Dentale Magnetresonanztomographie (Dental-MRT) als Verfahren zur Darstellung des maxillomandibulaeren Zahnhalteapparates

    Energy Technology Data Exchange (ETDEWEB)

    Gahleitner, A.; Nasel, C.; Schick, S.; Dorffner, S.; Imhof, H.; Trattnig, S. [Wien Univ. (Austria). Abt. fuer Osteologie; Bernhart, T.; Mailath, G.; Watzek, G. [Wien Univ. (Austria). Abt. fuer Orale Chirurgie

    1998-10-01

    Purpose: To establish a new method for dental imaging using magnetic resonance tomography named Dental-MRT and to demonstrate its usefulness in diagnosing dentogen pathologies of the mandible and maxilla. Methods: Seven healthy volunteers, three patients with pulpitis, two patients with dentigerous cysts, two patients after tooth transplantation, and three patients with atrophic mandibles have been evaluated. Optimized axial T{sub 1}- and T{sub 2}-weighted gradient echo and spin echo sequences in 2D and 3D technique have been established to perform studies of the jaws. The acquired images were reconstructed with a standard dental software package on a workstation as panorama and cross-sectional views of the mandible or maxilla. Results: The entire maxillo-mandibular bone, teeth, dental pulp, and the content of the mandibular canal were well depicted. Patients with pulpitis demonstrate bone marrow edema in the periapical region. Dentigerous cysts and their relation to the surrounding structures are clearly shown. After contrast media administration marked enhancement of the dental pulp can be demonstrated. Conclusion: Dental-MRT promises to provide a new tool for visualization and detection of dental diseases. (orig.) [Deutsch] Ziel: Das Vorstellen der Dental-MRT als neue Methode zur Darstellung des Ober- und Unterkiefers und ihre Anwendung bei der Diagnose zahnmedizinischer Erkankungen. Methoden: 7 gesunde Probanden, drei Patienten mit Pulpitis, zwei Patienten mit odontogenen Zysten, zwei Patienten nach Zahntransplantationen und drei Patienten mit atrophem Unterkiefer wurden untersucht. Optimierte axiale T{sub 1}- und T{sub 2}-gewichtete Gradienten-Echo- und Spin-Echo-Sequenzen in 2D und 3D-Technik wurden angewandt. Nach der Untersuchung wurden Panoramaschnitte und dentale Rekonstruktionen des Ober- und Unterkiefers, unter Verwendung einer gebraeuchlichen Dental-Software, angefertigt. Ergebnisse: Der gesamte Kieferbereich, Zaehne, Pulpa und der Inhalt des

  11. Investigations on uncertainties in patient positioning for prostate treatment with EPID; Untersuchungen zur Positionierungsgenauigkeit bei Prostatakonformationsbestrahlungen mittels Portal-Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Bakai, A.; Nuesslin, F. [Universitaetsklinik fuer Radioonkologie, Tuebingen (Germany). Abt. Medizinische Physik; Paulsen, F.; Plasswilm, L.; Bamberg, M. [Universitaetsklinik fuer Radioonkologie, Tuebingen (Germany). Abt. Strahlentherapie

    2002-02-01

    : Konformationstechniken, wie sie heutzutage routinemaessig fuer Patienten mit Prostatakarzinom angewandt werden erlauben, durch Adaption der Bestrahlungsfelder an das Planungszielvolumen (PTV) umliegendes Normalgewebe zu schonen. Um die Vorteile dieser Techniken jedoch vollstaendig nutzen zu koennen, ist die korrekte Patientenpositionierung eine wichtige Voraussetzung. In dieser Studie wurde mittels Portal-Imaging (EPID) untersucht, welche Positionierungsgenauigkeiten im Beckenbereich unter Verwendung unterschiedlicher Lagerungshilfen moeglich sind. Patienten und Methode: Fuer die Studie wurden 15 Patienten mit Prostatakarzinom ausgewaehlt, die teils mit, teils ohne Rektumballon bzw. Beckenmaske an einem Linearbeschleuniger mit Viellamellenblenden (MLC) bestrahlt wurden. Von jedem Patienten wurden mehrfach aus orthogonalen Richtungen mittels eines Portal-Imaging-Systems Aufnahmen angefertigt und anschliessend mit den Planungs-DRRs (digitally reconstructed radiographs) sowie den Simulationsaufnahmen verglichen. Ergebnisse: Trotz unterschiedlicher Lagerungshilfen konnten fuer saemtliche Patientengruppen Gesamtpositionierungsungenauigkeiten von durchschnittlich 4,0 mm (lateral), 4,5 mm (kraniokaudal) sowie 1,7 mm (dorsoventral) festgestellt werden. Mit Beckenmaske war der laterale Positionierungsfehler zwar reduziert, gleichzeitig jedoch der kraniokaudale Positionierungsfehler verstaerkt. Der Gesamtpositionierungsfehler teilte sich dabei in einen systematischen und einen statistischen Anteil auf, fuer deren verlaessliche Abschaetzung sechs bis acht EPID-Aufnahmen erforderlich waren. Schlussfolgerungen: Mittels Portal-Imaging ist es moeglich, aus einer geringen Anzahl von Verifikationsaufnahmen fuer jeden Patienten den systematischen und statistischen Positionierungsfehler zu ermitteln. Der erfolgreiche Einsatz von Lagerungshilfen zur Patientenpositionierung erfordert jedoch - insbesondere im Hinblick auf IMRT - eine weitere Optimierung. (orig.)

  12. Weanling piglet cerebellum: a surrogate for tolerance to MRT (microbeam radiation therapy) in pediatric neuro-oncology

    Science.gov (United States)

    Laissue, Jean A.; Blattmann, Hans; Di Michiel, Marco; Slatkin, Daniel N.; Lyubimova, Nadia; Guzman, Raphael; Zimmermann, Werner; Birrer, Stephan; Bley, Tim; Kircher, Patrick; Stettler, Regina; Fatzer, Rosmarie; Jaggy, Andre; Smilowitz, Henry; Brauer, Elke; Bravin, Alberto; Le Duc, Geraldine; Nemoz, Christian; Renier, Michel; Thomlinson, William C.; Stepanek, Jiri; Wagner, Hans-Peter

    2001-12-01

    The cerebellum of the weanling piglet (Yorkshire) was used as a surrogate for the radiosensitive human infant cerebellum in a Swiss-led program of experimental microbeam radiation therapy (MRT) at the ESRF. Five weanlings in a 47 day old litter of seven, and eight weanlings in a 40 day old litter of eleven were irradiated in November, 1999 and June, 2000, respectively. A 1.5 cm-wide x 1.5 xm-high array of equally space approximately equals 20-30 micrometers wide, upright microbeams spaced at 210 micrometers intervals was propagated horizontally, left to right, through the cerebella of the prone, anesthetized piglets. Skin-entrance intra-microbeam peak adsorbed doses were uniform, either 150, 300, 425, or 600 gray (Gy). Peak and inter-microbeam (valley) absorbed doses in the cerebellum were computed with the PSI version of the Monte Carlo code GEANT and benchmarked using Gafchromic and radiochromic film microdosimetry. For approximately equals 66 weeks [first litter; until euthanasia], or approximately equals 57 weeks [second litter; until July 30, 2001] after irradiation, the littermates were developmentally, behaviorally, neurologically and radiologically normal as observed and tested by experienced farmers and veterinary scientists unaware of which piglets were irradiated or sham-irradiated. Morever, MRT implemented at the ESRF with a similar array of microbeams and a uniform skin-entrance peak dose of 625 Gy, followed by immunoprophylaxis, was shown to be palliative or curative in young adult rats bearing intracerebral gliosarcomas. These observations give further credence to MRT's potential as an adjunct therapy for brain tumors in infancy, when seamless therapeutic irradiation of the brain is hazardous.

  13. Multiparametric MRI of the prostate. Important radiological findings for urologists; Multiparametrische MRT der Prostata. Wichtige radiologische Befunde fuer den Urologen

    Energy Technology Data Exchange (ETDEWEB)

    Schlemmer, Heinz-Peter [Deutsches Krebsforschungszentrum (DKFZ), Heidelberg (Germany)

    2017-08-15

    High prevalence of prostate cancer with multifocality and biological heterogeneity. Insufficient conventional urological diagnostics. Discrimination between significant and insignificant cancer needed. Digital rectal examination, prostate-specific antigen (PSA) serum level, systematic transrectal ultrasound (TRUS)-guided prostate biopsy. Multiparametric magnetic resonance imaging (mpMRI) including T2-weighted (T2w), diffusion-weighted and dynamic contrast-enhanced MRI according to the prostate imaging reporting and data system (PIRADS), MR-targeted biopsy, most frequently MR/TRUS image fusion biopsy. Prostate cancer is characterized by low signal intensity on T2w MRI, restricted water diffusion and pronounced and early uptake of contrast enhancement. Sensitivity and specificity according to the current literature are ca. 80% and 90%, respectively. In cases of suspected prostate cancer, most accurate are mpMRI according to PIRADS and in cases of positive findings, MRI-targeted biopsy, most frequently as MRI/TRUS image fusion biopsy. (orig.) [German] Hohe Praevalenz des Prostatakarzinoms mit Multifokalitaet und biologischer Heterogenitaet. Unzureichende konventionelle urologische Diagnostik. Unterscheidung klinisch signifikanter von klinisch nicht signifikanten Karzinomen erforderlich. Digitale rektale Untersuchung, Serum-PSA (prostataspezifisches Antigen), transrektale Sonographie (TRUS), systematische transrektale TRUS-Biopsie. Multiparametrische Magnetresonanztomographie (mpMRT) mit T2w- und diffusionsgewichteten sowie dynamischen kontrastmittelverstaerkten T1w-Sequenzen, dem Standard nach dem Prostate Imaging Reporting and Data System (PIRADS) entsprechend. MR-unterstuetzte Biopsie, meist MR-/TRUS-Fusionsbiopsie. Prostatakarzinome sind typischerweise T2-hypointens mit eingeschraenkter Diffusion und zeigen eine rasche Kontrastmittelanflutung. Nach der Literatur betragen Sensitivitaet und Spezifitaet der mpMRT ca. 80 bzw. 90 %. Fuer die Abklaerung bei Verdacht auf

  14. Assessment of manual restorative treatment (MRT) with amalgam in high-caries Filipino children: results after 2 years.

    Science.gov (United States)

    Monse-Schneider, B; Heinrich-Weltzien, R; Schug, D; Sheiham, A; Borutta, A

    2003-04-01

    The atraumatic restorative treatment (ART), using only hand instruments and glass-ionomer cement as adhesive material is recommended for restorative dental treatment in disadvantaged communities lacking electricity and sophisticated dental equipment. Research is required on more durable restorative materials appropriate for populations with high-caries experience. The aim of the study was to evaluate, under field conditions, the applicability and effectiveness of an encapsulated amalgam as restorative material in ART prepared cavities in permanent teeth of children with high-caries rates. As the definition of ART restricts the manual treatment to adhesive materials the approach used is called the manual restorative treatment (MRT). Two dentists and two trained healthcare workers, using hand instruments and an encapsulated amalgam that was mixed with a manually driven triturator, placed a total of 934 restorations in the permanent dentition in 466 children. Due to irregular school attendance of Filipino children only 611 restorations could be evaluated by one independent dentist. The average age at reassessment of restorations was 27 +/- 4.5 months. 93.3% of the restorations were acceptable. The failure rate of occlusal surface restorations was 5.6% compared with 13.6% of buccal surface fillings. The survival rate of large occlusal restorations was 95.1% compared with 93.7% for small restorations. The survival of MRT restorations was not influenced by the experience and professional level of the operator. Amalgam is a suitable MRT material, especially for extensive occlusal lesions in high-caries populations. Studies of longer duration are needed to confirm this finding.

  15. Clinical value of MRI concerning dissection of the supraaortic vessels; Wertigkeit der MRT bei posttraumatischer Dissektion supraaortaler Gefaesse

    Energy Technology Data Exchange (ETDEWEB)

    Pauls, S.; Goerich, J.; Kraemer, S. [Abt. fuer Diagnostische Radiologie, Univ. Ulm (Germany); Hartwig, E. [Unfall- und Wiederherstellungschirurgie, Univ. Ulm (Germany)

    2002-03-01

    Purpose: Evaluation of the potential of MRI concerning dissection of the supra-aortic vessels after cervical trauma. Patients and methods: During the time period from August 1998 to February 2001, 148 patients with trauma were examined by means of MRI scan of the neck / cervical spine or skull concerning morphology of the cervical spine as well as the brain tissue. MRI sequences were weighted T{sub 1} and T{sub 2} before and after contrast medium in transverse and sagittal slices. Additional time of flight (TOF) sequences and contrast-enhanced angiography were acquired. The MRI images were examined by two experienced radiologists when tied consensus was reached. Results: 7 patients (4,7%) with a total of 9 dissections of the vertebral and/or internal carotid artery were found; diagnosis was done on TOF images, contrast enhances MR-angiography, transversal T{sub 1}- and T{sub 2}-weighted sequences as well as T{sub 1}-weighted images post-contrast medium. Therapy was changed accordingly in 4 cases and anticoagulation initiated. Conclusion: All patients with cervical injuries should be screened by MRI including MR-angiography, T{sub 1}-weighted images pre- and post-contrast agent to achieve a sure diagnosis concerning the precise size of the dissection. MRI has proven to be an excellent diagnostic tool for our patient group. (orig.) [German] Ziel: Beurteilung der Bedeutung der MRT bezueglich der Dissektionen supraaortaler Gefaesse im Rahmen cervicaler Traumata. Patienten und Methode: Im Zeitraum von August 1998 bis Februar 2001 wurden an unserer Klinik 148 Patienten mit Traumata zugewiesen, welche zur Abklaerung einer Gefuegestoerung der HWS bzw. Ausschluss einer Myelonaffektion eine MRT-Untersuchung des Halses / der HWS oder Schaedels erhielten. Es wurden jeweils T{sub 1}- und T{sub 2}-gewichtete Sequenzen in transversaler und sagittaler Schnittfuehrung vor und nach Kontrastmittelgabe angefertigt. Zusaetzlich wurden TOF-Sequenzen sowie kontrastunterstuetzte

  16. Abdominal fat-evaluation by use of single scan computed tomography; Computertomographische Bestimmung des intraabdominellen Fettvolumens mittels Einschicht-Messung

    Energy Technology Data Exchange (ETDEWEB)

    Jacobi, V. [Klinikum der Johann-Wolfgang-Goethe-Univ., Frankfurt am Main (Germany). Inst. fuer Allgemeine Roentgendiagnostik; Steinkamp, M. [Klinikum der Johann-Wolfgang-Goethe-Univ., Frankfurt am Main (Germany). Inst. fuer Allgemeine Roentgendiagnostik; Kirchner, J. [Klinikum der Johann-Wolfgang-Goethe-Univ., Frankfurt am Main (Germany). Inst. fuer Allgemeine Roentgendiagnostik; Fischer, H. [Klinikum der Johann-Wolfgang-Goethe-Univ., Frankfurt am Main (Germany). 2. Medizinische Klinik; Diedrich, C.F. [Klinikum der Johann-Wolfgang-Goethe-Univ., Frankfurt am Main (Germany). 2. Medizinische Klinik; Kollath, J. [Klinikum der Johann-Wolfgang-Goethe-Univ., Frankfurt am Main (Germany). 2. Medizinische Klinik

    1997-02-01

    Purpose: Several studies emphasised the importance of the relationship between intraabdominal and total body adipose tissue as a risk factor for the development of metabolic or cardiovascular diseases. Therefore, the aim of the present study was to examine whether a single scan computed tomography is able to determine the whole intraabdominal fat volume with high accuracy and reproducibility. Materials and methods: Regions of interests (ROIs) were drawn manually for measuring intraabdominal fat in 51 unsuspicious abdominal CT. Results: The sexual differentiation of adipose tissue already described in a lot of studies could be confirmed in this study. Fat still predominates in females in lower half of the body (gynoid obesity). In men it predominates in the upper half (android obesity). Significant correlation concerning measuring the whole intraabdominal fat volume could be found in L1-level in women (r=0.992) and in L2-level in men (r=0.992). Measurement of a single scan enables us to assess whole intraabdominal fat volume due to a special formula. Conclusion: The determination of intraabdominal fat measured by a single scan computed tomography is a procedure associated with high accuracy and reproducibility. (orig.) [Deutsch] Ziel: Da in zahlreichen Studien hervorgehobene Bedeutung des intraabdominellen Fettgewebes gegenueber dem Gesamtkoerperfett als Risikofaktor fuer die Entwicklung metabolischer und kardiovaskulaerer Erkrankungen fordert ein Verfahren zur annaehernd exakten Bestimmung des intraabdominellen Fettgewebes. Ziel der vorliegenden Studie war zu pruefen, ob mit genuegender Genauigkeit die Verwendung einer Einschicht-Methode einen gezielten Einsatz der Computertomographie ermoeglicht und welche Lokalisation der zu waehlenden Schicht die aussagekraeftigste Messung ermoeglicht. Material und Methode: Anhand von 51 Computertomographien des Abdomens anderer Indikation (Normalbefunde) wurde das gesamte intraabdominelle Fettvolumen semiautomatisch mittels ROI

  17. MR imaging of the lateral collateral ligaments after ankle sprain; Aussenbandrupturen des Sprunggelenkes - Darstellung mit der MRT vor und nach funktioneller Therapie

    Energy Technology Data Exchange (ETDEWEB)

    Grebe, P. [Klinik fuer Radiologie der Universitaetsklinik, Mainz (Germany); Kreitner, K.F. [Klinik fuer Radiologie der Universitaetsklinik, Mainz (Germany); Roeder, W. [Abt. fuer Chirurgie, St-Hildegardis-Krankenhaus, Mainz (Germany); Kersjes, W. [Klinik fuer Radiologie der Universitaetsklinik, Mainz (Germany); Hennes, R. [Abt. fuer Allgemein- und Unfallchirurgie, St. Josefshospital, Wiesbaden (Germany); Runkel, M. [Unfallchirurgische Klinik der Unversitaetsklinik, Mainz (Germany)

    1995-09-01

    35 patients with ankle sprain were examined by MRI and stress radiographs. 13 were operated afterwards, 22 patients underwent a functional conservative therapy and were examined by MRI and stress radiographs and second time after three months. MRI reports were correct in 12 of 13 operated cases. After conservative therapy we did not find any disrupted ankle ligament. MRI showed intact ligaments thickened by scar. (orig./MG) [Deutsch] 35 Patienten mit klinischem Verdacht auf Aussenbandruptur wurden mit der MRT untersucht. 13 Patienten wurden operiert, 22 konzervativ therapiert. Letztere wurden nach drei Monaten erneut mit MRT und gehaltenen Aufnahmen untersucht. Die MRT-Befunde stimmten in 12 von 13 Faellen mit den operativ erhobenen Befunden ueberein. Nach dreimonatiger konzervativer Therapie waren alle 22 Sprunggelenke stabil. Die rupturierten Baender stellten sich verdickt und durchgaengig dar. (orig./MG)

  18. MR of the liver in Wilson`s disease; MRT der Leber bei Morbus Wilson

    Energy Technology Data Exchange (ETDEWEB)

    Vogl, T.J. [Strahlenklinik und Poliklinik, Universitaetsklinikum Rudolf Virchow, Freie Univ. Berlin (Germany); Steiner, S. [Klinikum Grosshadern, Radiologische Klinik und Poliklinik, Univ. Muenchen (Germany); Hammerstingl, R. [Strahlenklinik und Poliklinik, Universitaetsklinikum Rudolf Virchow, Freie Univ. Berlin (Germany); Schwarz, S. [Klinikum Grosshadern, Neurologische Klinik, Univ. Muenchen (Germany); Kraft, E. [Klinikum Grosshadern, Neurologische Klinik, Univ. Muenchen (Germany); Weinzierl, M. [Klinikum Grosshadern, 2. Medizinische Klinik, Univ. Muenchen (Germany); Felix, R. [Strahlenklinik und Poliklinik, Universitaetsklinikum Rudolf Virchow, Freie Univ. Berlin (Germany)

    1994-01-01

    To show that Wilson`s disease is one likely cause of multiple low-intensity nodules of the liver we obtained MR images in 16 patients with clinically and histopathologically confirmed Wilson`s disease. Corresponding to morphological changes MRI enabled the subdivision of the patients into two groups. Using a T{sub 2}-weighted spin-echo sequence (TR/TE=2000/45-90) liver parenchyma showed multiple tiny low-intensity-nodules surrounded by high-intensity septa in 10 out of 16 patients. 5 patients had also low-intensity nodules in T{sub 1}-weighted images (TR/TE=600/20). In patients of this group histopathology revealed liver cirrhosis (n=7) and fibrosis (n=2). Common feature of this patient group was marked inflammatory cell infiltration into fibrous septa, increase of copper concentration in liver parenchyma and distinct pathological changes of laboratory data. In the remaining 6 patients no pathological change of liver morphology was demonstrated by MRI corresponding to slight histopathological changes of parenchyma and normal laboratory data. As low-intensity nodules surrounded by high intensity septa can be demonstrated in patients with marked inflammatory infiltration of liver parenchyma MRI may help to define Wilson patients with poorer prognosis. In patients with low-intensity nodules of the liver and unknown cause of liver cirrhosis laboratory data and histopathology should be checked when searching for disorders of copper metabolism. (orig.) [Deutsch] Im Rahmen einer prospektiven Studie wurde die Leber bei 16 Patienten mit klinisch gesichertem Morbus Wilson magnetresonanztomographisch untersucht. Zum Einsatz kamen T{sub 1}- und T{sub 2}-gewichtete Spin-Echo-Sequenzen vor und nach Applikation von Gd-DTPA (0,1 mmol/kg KG). Anhand der MRT-Befunde konnten zwei unterschiedliche Patientenkollektive definiert werden. 10 Patienten wiesen in der T{sub 2}-gewichteten Sequenz hypointense Regeneratknoten auf und zeigten histopathologisch ausgepraegte Befunde einer

  19. Monitoring of lead batteries by means of optical-fibre refractometry; Ueberwachung von Bleiakkumulatoren mittels Faseroptischer Refraktometrie

    Energy Technology Data Exchange (ETDEWEB)

    Gernhold, H P; Hanitsch, R

    1994-12-31

    Electricity storage is an integral part of photovoltaic systems. At the moment, the most economical device for this is the lead battery. Battery life is determined by the charging technique applied and by the efficiency of monitoring. The optimum charging technique is selected in dependence of battery age and charge state. The authors present a method for online charge state monitoring in which the acid concentration is measured by means of optical-fibre refractometry. (orig.) [Deutsch] Ein aeusserst wichtiger Teilbereich von Photovoltaik-Anlagen ist die Speicherung von elektrischer Energie. Diesen Zweck erfuellen Bleiakkumulatoren zur Zeit am wirtschaftlichsten. Es hat sich gezeigt, dass sowohl die angewandte Ladetechnik als auch eine gute Batterieueberwachung entscheidend fuer die Lebensdauer dieser Systemkomponente sind. Die Wahl der optimalen Ladetechnik richtet sich wiederum nach dem Alter und dem Entladegrad der Batterie. Gegenstand dieser Arbeit ist es, eine Methode vorzustellen, mit der die Saeuredichte mittels faseroptischer Refraktometrie gemessen und so der Ladezustand jeder einzelnen Batteriezelle zu jedem Zeitpunkt on-line ueberwacht werden kann. (orig.)

  20. Kino filmų titrai kaip kalbų mokymosi priemonė. Untertitel als Mittel zum Fremdsprachenerwerb

    Directory of Open Access Journals (Sweden)

    Alina Baravykaitė

    2007-01-01

    Full Text Available Das in den letzten Jahren spürbare Bestreben der litauischen Gesetzgeber, Untertitelung von Fernsehfilmen zwecks Fremdsprachenerwerb gesetzlich anzuordnen, löste eine Auseinandersetzung in der Öffentlichkeit aus, die sich in der Presse sowie im Internet widerspiegelt und als Anstoß zum vorliegenden Beitrag dient. Diese Arbeit stellt den Versuch dar, die Möglichkeiten und Grenzen der Untertitelung als eines Mittels zum Fremdsprachenerwerb zu untersuchen. Auf Grund der fehlenden wissenschaftlichen Forschungen in diesem Bereich sollen dabei empirische Betrachtungen und die vergleichende Textanalyse von Original und Übersetzung als Hilfe dienen. Auch wenn die Relevanz der Untertitelung für den Fremdsprachenerwerb nicht bestreitbar ist, ist sie aber zugleich nicht zu überschätzen: Durch die lediglich für diese Form der audiovisuellen Übersetzung charakteristischen Merkmale (kurze Einblendezeit, kondensierte Sprache und begrenzte Übertragungsmöglichkeiten von Realia-Begriffen, Phraseologismen, Intertextualismen, dem Wortspiel etc. bleiben dem Zuschauer oft sprachliche Stilmittel vorenthalten und der in allen Übersetzungsbereichen vorkommende unausweichliche Sinn- und Wirkungsverlust des Originals wird erheblich verstärkt. Anbetracht der erwähnten Aspekte und der häufigen fehlerhaften Übersetzungen sollen Untertitel nur als Hilfsmittel beim Fremdsprachenerwerb angewendet werden, wobei herkömmliche Lehr- und Lernstrategien von Fremdsprachen in den Vordergrund treten müssen.

  1. Simultaneous whole-body PET-MRI in pediatric oncology. More than just reducing radiation?; Simultane Ganzkoerper-PET-MRT in der paediatrischen Onkologie. Mehr als nur Strahlenersparnis

    Energy Technology Data Exchange (ETDEWEB)

    Gatidis, S.; Gueckel, B.; Schaefer, J.F. [Universitaet Tuebingen, Radiologische Klinik, Diagnostische und Interventionelle Radiologie, Tuebingen (Germany); Fougere, C. la [Universitaet Tuebingen, Radiologische Klinik, Nuklearmedizin, Tuebingen (Germany); Schmitt, J. [Universitaet Tuebingen, Abteilung fuer Praeklinische Bildgebung und Radiopharmazie, Werner Siemens Imaging Center, Tuebingen (Germany)

    2016-07-15

    Diagnostic imaging plays an essential role in pediatric oncology with regard to diagnosis, therapy-planning, and the follow-up of solid tumors. The current imaging standard in pediatric oncology includes a variety of radiological and nuclear medicine imaging modalities depending on the specific tumor entity. The introduction of combined simultaneous positron emission tomography (PET) and magnetic resonance imaging (MRI) has opened up new diagnostic options in pediatric oncology. This novel modality combines the excellent anatomical accuracy of MRI with the metabolic information of PET. In initial clinical studies, the technical feasibility and possible diagnostic advantages of combined PET-MRI have been in comparison with alternative imaging techniques. It was shown that a reduction in radiation exposure of up to 70 % is achievable compared with PET-CT. Furthermore, it has been shown that the number of imaging studies necessary can be markedly reduced using combined PET-MRI. Owing to its limited availability, combined PET-MRI is currently not used as a routine procedure. However, this new modality has the potential to become the imaging reference standard in pediatric oncology in the future. This review article summarizes the central aspects of pediatric oncological PET-MRI based on existing literature. Typical pediatric oncological PET-MRI cases are also presented. (orig.) [German] Die bildgebende Diagnostik spielt in der paediatrischen Onkologie eine zentrale Rolle fuer die Diagnose, die Therapieplanung und die Nachsorge solider Tumoren. Der aktuell bildgebende Standard in der paediatrischen Onkologie sieht - abhaengig von der vorliegenden Tumorentitaet - eine Kombination mehrerer radiologischer und nuklearmedizinischer Verfahren vor. Die Einfuehrung der simultanen Positronenemissionstomographie(PET)-Magnetresonanztomographie (MRT) hat neuartige Moeglichkeiten der Diagnostik in der paediatrischen Onkologie eroeffnet. Dabei kombiniert dieses neue Verfahren die

  2. Dental magnetic resonance tomography (dental-MRT) as a method for imaging of the maxillo-mandibular bone

    International Nuclear Information System (INIS)

    Gahleitner, A.; Nasel, C.; Schick, S.; Dorffner, S.; Imhof, H.; Trattnig, S.; Bernhart, T.; Mailath, G.; Watzek, G.

    1998-01-01

    Purpose: To establish a new method for dental imaging using magnetic resonance tomography named Dental-MRT and to demonstrate its usefulness in diagnosing dentogen pathologies of the mandible and maxilla. Methods: Seven healthy volunteers, three patients with pulpitis, two patients with dentigerous cysts, two patients after tooth transplantation, and three patients with atrophic mandibles have been evaluated. Optimized axial T 1 - and T 2 -weighted gradient echo and spin echo sequences in 2D and 3D technique have been established to perform studies of the jaws. The acquired images were reconstructed with a standard dental software package on a workstation as panorama and cross-sectional views of the mandible or maxilla. Results: The entire maxillo-mandibular bone, teeth, dental pulp, and the content of the mandibular canal were well depicted. Patients with pulpitis demonstrate bone marrow edema in the periapical region. Dentigerous cysts and their relation to the surrounding structures are clearly shown. After contrast media administration marked enhancement of the dental pulp can be demonstrated. Conclusion: Dental-MRT promises to provide a new tool for visualization and detection of dental diseases. (orig.) [de

  3. Craniocerebral trauma. Magnetic resonance imaging of diffuse axonal injury; Schaedel-Hirn-Trauma. MRT bei diffuser axonaler Verletzung

    Energy Technology Data Exchange (ETDEWEB)

    Mallouhi, A. [Medizinische Universitaet Wien, Allgemeines Krankenhaus, Abteilung fuer Neuro- und Muskuloskelettale Radiologie, Klinik fuer Radiologie und Nuklearmedizin, Wien (Austria)

    2014-09-15

    fuer Behinderung oder Tod. Es fuehrt haeufig zu einer axonalen Scherverletzung. Die daraus resultierende Pathologie wird als diffuse axonale Verletzung (''diffuse axonal injury'', DAI) bezeichnet. Die DAI-assoziierten Laesionen treten bilateral und verteilt auf und werden in der oberflaechlichen und in der tiefen weissen Substanz beobachtet. Sie finden sich sowohl in der Naehe als auch weit entfernt von der Aufprallstelle. Bei klinischem Verdacht auf eine diffuse axonale Verletzung ist die Magnetresonanztomographie (MRT) zur weiteren Abklaerung die Methode der Wahl, dies insbesondere bei Patienten mit einer unauffaelligen Computertomographie des Schaedels. Zur Abklaerung des Gehirns nach einem Schaedel-Hirn-Trauma (SHT) wird ein multimodales MR-Verfahren angewendet, das in 2 Kategorien unterteilt werden kann: strukturelle und funktionelle MR-Bildgebung. Fuer die strukturelle MRT kommen hauptsaechlich die Fluid-attenuated-inversion-recovery(FLAIR)-Gewichtung und die suszeptibilitaetsgewichtete Bildgebung (SWI) zum Einsatz. Die SWI ist ausserordentlich auf Blutabbauprodukte empfindlich, welche als kleine Signalausloeschungen an 3 typischen Lokalisationen (an der Rinden-Mark-Grenzzone, im Corpus callosum und im Hirnstamm) zur Darstellung kommen. Die funktionelle MRT umfasst eine Gruppe staendig in Entwicklung befindlicher Techniken, welche ein grosses Potenzial zur optimalen Evaluierung der weissen Substanz bei Patienten nach einem SHT haben. Diese modernen bildgebenden Verfahren ermoeglichen die Visualisierung der mit Scherverletzungen assoziierten Veraenderungen, wie die Funktionsbeeintraechtigung der Axone, die verminderte Durchblutung und abnormale metabolische Aktivitaet der betroffenen Gehirnanteile. Die multimodale MR-Abklaerung bei Patienten mit DAI fuehrt zu einer detaillierteren und differenzierteren Darstellung der zugrunde liegenden pathophysiologischen Veraenderungen der verletzten Nervenbahnen und traegt zur Verbesserung der

  4. Incidence and significance of small focal liver lesions on MRI; Haeufigkeit und Bedeutung von kleinen fokalen Leberlaesionen in der MRT

    Energy Technology Data Exchange (ETDEWEB)

    Kreft, B.; Pauleit, D.; Bachmann, R.; Conrad, R.; Kraemer, A.; Schild, H.H. [Bonn Univ. (Germany). Radiologische Klinik

    2001-05-01

    Analysis of the frequency and significance of small focal liver lesions ({<=} 2 cm) detected on MRI in the presence or absence of a history of malignancy. Methods: 628 MRI examinations of the liver performed during 1994 - 1996 were evaluated. The inclusion criterion into the study was the detection of a focal liver lesion with a size {<=} 2 cm. The frequency, the size, the diagnostic proof, and the differential diagnosis of the focal liver lesions were analysed with regard to the patients history of a known malignant tumor. Results: Overall, 179 of the 628 patients (28.5%) had focal liver lesions {<=} 2 cm (n = 338). 58.9% of the lesions could be classified based upon follow-up studies by ultrasound, CT or MRI, or by biopsy. The remaining 41.1% of the lesions could not be classified due to the absence of follow-up examinations. 57.3% of all proven lesions were benign and 42.7% were malignant. A history of a malignant tumor was present in 76.7% of all patients with small liver lesions; however, lesions were benign in these patients in 50.6% of the cases. In patients with no known history of a malignancy, 75% of the lesions were benign and 25% were malignant. However, these malignant lesions were in 10/11 cases hepatocellular carcinomas in patients with liver cirrhosis. (orig.) [German] Analyse der Haeufigkeit und der Bedeutung von kleinen Leberlaesionen ({<=} 2 cm) in der MRT in Abhaengigkeit einer vorbestehenden Tumoranamnese. Methode: Es wurden insgesamt 628 MRT-Untersuchungen der Leber aus dem Zeitraum von 1994-1996 ausgewertet. Einschlusskriterium in die Studie war der Nachweis von Leberlaesionen mit einer Groe paragraph e {<=} 2 cm, wobei die Haeufigkeit, die Groe paragraph enverteilung, die Diagnosesicherung und die Differenzialdiagnose in Abhaengigkeit von der Anamnese einer Tumorerkrankung untersucht wurden. Ergebnisse: Insgesamt wiesen 179 der 628 Patienten (28,5%) fokale Leberlaesionen {<=} 2 cm (n = 338) auf. 58,9% der Laesionen konnten aufgrund von

  5. Einfluss der Lage des aktiven Kontaktes innerhalb des Nucleus subthalamicus auf den Effekt der tiefen Hirnstimulation bei Parkinson Patienten- Eine MRT-basierte Untersuchung

    OpenAIRE

    Wodarg, Fritz

    2013-01-01

    Anhand Prä- und postoperativer MRT-Bilder wird die Lage der Elektroden zur Hochfrequenzstimulation innerhalb des N. subthalamicus bestimmt und mit dem klinischen Ergebnis der Stimulation bei 30 Parkinson Patienten korreliert. Eine Stimulation in lateralen Anteilen des STN bringt signifikant bessere klinische Ergebnisse.

  6. Simulation of the beam guiding of the SAPHIR experiment by means of a differential-equation model; Simulation der Strahlfuehrung des SAPHIR-Experiments mittels eines Differentialgleichungsmodells

    Energy Technology Data Exchange (ETDEWEB)

    Greve, T.

    1991-08-01

    This paper shows the numerical simulation of a beam line by means of a model of differential equations simulating the beam line from the Bonn Electron Stretcher Accelerator ELSA to the SAPHIR spectrometer. Furthermore a method for calculating the initial values based on measurements of beam profiles is being discussed. (orig.). [Deutsch] Diese Arbeit zeigt die numerische Simulation einer Strahlfuehrung mittels eines Differentialgleichungsmodells anhand der Strahlfuehrung vom Bonner ELSA-Beschleuniger zum SAPHIR-Experiment. Weiterhin wird eine Methode zur Gewinnung der Startwerte aus Strahlprofilmessungen diskutiert. (orig.).

  7. Molecular imaging of head and neck cancers. Perspectives of PET/MRI; Molekulare Bildgebung bei Kopf-ï]¿Hals-Tumoren. Perspektive der PET-MRT

    Energy Technology Data Exchange (ETDEWEB)

    Stumpp, P.; Kahn, T. [Universitaetsklinikum Leipzig AoeR, Klinik und Poliklinik fuer Diagnostische und Interventionelle Radiologie, Leipzig (Germany); Purz, S.; Sabri, O. [Universitaetsklinikum Leipzig, Klinik und Poliklinik fuer Nuklearmedizin, Leipzig (Germany)

    2016-07-15

    The {sup 18}F-fluorodeoxyglucose positron emission tomography-computed tomography ({sup 18}F-FDG-PET/CT) procedure is a cornerstone in the diagnostics of head and neck cancers. Several years ago PET-magnetic resonance imaging (PET/MRI) also became available as an alternative hybrid multimodal imaging method. Does PET/MRI have advantages over PET/CT in the diagnostics of head and neck cancers ?The diagnostic accuracy of the standard imaging methods CT, MRI and PET/CT is depicted according to currently available meta-analyses and studies concerning the use of PET/MRI for these indications are summarized. In all studies published up to now PET/MRI did not show superiority regarding the diagnostic accuracy in head and neck cancers; however, there is some evidence that in the future PET/MRI can contribute to tumor characterization and possibly be used to predict tumor response to therapy with the use of multiparametric imaging. Currently, {sup 18}F-FDG-PET/CT is not outperformed by PET/MRI in the diagnostics of head and neck cancers. The additive value of PET/MRI due to the use of multiparametric imaging needs to be investigated in future research. (orig.) [German] Die {sup 18}F-Fluordesoxyglukose-Positronenemissionstomographie-Computertomographie ({sup 18}F-FDG-PET-CT) hat ihren festen Stellenwert in der Diagnostik von Kopf-Hals-Tumoren. Seit einigen Jahren ist die PET-MRT als weitere hybride Bildgebungsmodalitaet verfuegbar. Bringt die PET-MRT Fortschritte bei der Diagnostik von Kopf-Hals-Tumoren ?Darstellung der diagnostischen Genauigkeit der bisherigen Bildgebungsmethoden CT, MRT und PET-CT anhand von Metaanalysen und Zusammenfassung der bisherigen Publikationen zur PET-MRT auf diesem Gebiet. Die PET-MRT zeigt in allen bisherigen Studien keine Ueberlegenheit bzgl. der diagnostischen Genauigkeit von Kopf-Hals-Tumoren. Sie kann jedoch durch die multiparametrische Diagnostik perspektivisch Beitraege zur Tumorcharakterisierung und damit moeglicherweise Voraussagen zum

  8. Imaging diagnostics of the wrist: MRI and Arthrography/Arthro-CT; Bildgebende Diagnostik des Handgelenkes: MRT und Arthrographie/Arthro-CT

    Energy Technology Data Exchange (ETDEWEB)

    Klein, H.M.; Balas, R.; Neugebauer, F. [Radiologische Gemeinschaftspraxis, Betzdorf (Germany); Vrsalovic, V. [Handchirugie, Marienhospital Siegen, Siegen (Germany)

    2002-02-01

    Purpose: To evaluate the use of magnetic resonance imaging (MRI) compared with arthrography and arthro-CT (AG/ACT) in patients with wrist pain. Methods: MRI and arthrography/arthro-CT (AG/ACT) of the wrist joint were retrospectively evaluated in 346 patients over a three-year period. Imaging findings were correlated to surgical results (n=78) or clinical course in an at least 6-month follow-up. Results: For tears of the triangular fibrocartilage, arthrography, arthro-CT, and MRI demonstrated a sensitivity and specificity of more than 0.96. Only the positive predictive value was superior for arthrography/arthro-CT (0.99 and 0.98, respectively) compared with MRI (0.94). Arthrography was superior for functional diagnosis of scapho-lunate ligament tears (n=25). Ulno-lunate and ulno-triquetral ligament defects were demonstrated more exactly by arthrography. Traumatic osseous defects, particularly scaphoid fractures (n=33) and avascular necrosis (n=17), were better diagnosed using MRI. Conclusion: For suspected lesions of the triangular fibrocartilage complex, AG/ACT is slightly more reliable than MRI. However, MRI was found to be highly accurate in diagnosing TFC tears, and is superior to AG/ACT in detecting traumatic and vascular lesions of the wrist. (orig.) [German] Ziel: Die Untersuchung der diagnostischen Aussagekraft von Magnetresonanz-Tomographie (MRT), Arthrographie (AG) und Arthro-CT (ACT) bei Erkrankungen des Handgelenkes. Methodik: Insgesamt 346 Untersuchungen des Handgelenkes wurden fuer einen dreijaehrigen Beobachtungszeitraum retrospektiv ausgewertet. Es wurden 211 MRT, 151 Arthrographien (AG) und 126 Arthro-CT (ACT) durchgefuehrt. Alle Diagnosen wurden operativ (n=78) oder durch den klinischen Verlauf in einer 6-monatigen Nachbeobachtung gesichert. Ergebnisse: Fuer die Diagnostik von Laesionen des diskoulnaren Komplexes lag die Sensitivitaet und Spezifitaet von AG, ACT und MRT ueber 0,96. Lediglich der positive Vorhersagewert differierte, allerdings nicht

  9. Floating venous thrombi: diagnosis with spiral-CT-venography; Diagnose flottierender venoeser Thromben mittels Phlebo-Spiral-CT

    Energy Technology Data Exchange (ETDEWEB)

    Gartenschlaeger, M. [Mainz Univ. (Germany). Klinik fuer Radiologie; Klose, K.J. [Univ. Marburg, Medizinisches Zentrum fuer Innere Medizin, Abt. Poliklinik (Germany); Schmidt, J.A. [Univ. Marburg, Medizinisches Zentrum fuer Radiologie, Abt. fuer Strahlendiagnostik (Germany)

    1996-05-01

    Local application of contrast agent into an ipsilateral dorsal foot vein and spiral CT were used to examine 16 consecutive cases with deep venous thrombosis proven at conventional venography; in addition, colour Doppler flow imaging was performed. At conventional venography, 8/16 thrombi appeared to be floating and the remaining 8/16 were adherent to the vessel wall. Spiral-CT showed 15/16 thrombi to be adherent to the vessel wall; the floating thrombus correlated with findings in conventional venography. At colour Doppler flow imaging 3/16 thrombi were considered floating, one of them was discordant to conventional venography. The comparison of conventional venography to spiral-CT demonstrates complete agreement for adherence to vessel wall seen in conventional venography (p=1,0) and significant discordance in cases with free-floating appearance in conventional venography. Adherence of thrombi to the wall of the vessel at conventional venography is in agreement with computed tomography. Conventional venography probably overestimates the prevalence of free floating thrombi. (orig./MG) [Deutsch] Mittels lokaler Kontrastmittelapplikation in eine ipsilaterale Fussrueckenvene und Spiral-CT wurden 16 konsekutive Faelle konventionell phlebographisch gesicherter Phlebothrombose untersucht, zusaetzlich wurde die farbkodierte Doppler-Ultraschalluntersuchung durchgefuehrt. In der konventionellen Phlebographie waren 8/16 Thromben flottierend, die uebrigen 8/16 wandadhaerent. In der Spiral-CT zeigten sich Wandadhaerenzen in 15/16 Faellen; der nachgewiesene flottierende Thrombus stimmte mit der konventionellen Phlebographie ueberein. Im farbkodierten Doppler-Ultraschall erschienen die Thromben in 3/16 Faellen flottierend, darunter ein von der konventionellen Phlebographie abweichender Befund. Der Vergleich von konventioneller und CT-Phlebographie ergab eine komplette Uebereinstimmung fuer konventionell phlebographisch nachgewiesene Wandadhaerenz und eine signifikante Abweichung

  10. Imaging technique and current status of valvular heart disease using cardiac MRI; Untersuchungstechniken und Stellenwert der MRT bei der Diagnostik von Herzklappenerkrankungen

    Energy Technology Data Exchange (ETDEWEB)

    Lotz, J.; Sohns, J.M. [Universitaetsmedizin Goettingen, Georg-August-Universitaet, Institut fuer Diagnostische und Interventionelle Radiologie, Goettingen (Germany)

    2013-10-15

    The main indications for cardiac magnetic resonance imaging (MRI) in the evaluation of valvular heart disease are pathologies of the aortic and pulmonary valve. For mitral and tricuspid valve pathologies MRI is not the first line modality as these are usually well visualized by echocardiography. The advantages of MRI in valvular heart disease are a high reliability in the evaluation of ventricular volumes and function as well as the assessment of the perivalvular arterial or atrial structures. This reliability and the limitless access to any imaging plane partially compensates for the lower temporal and spatial resolution in comparison to echocardiography. In patients with congenital heart disease, cardiac MRI is established as a valuable diagnostic tool in daily clinical management, especially for the evaluation of pulmonary valve defects. Nevertheless, echocardiography remains the first-line diagnostic imaging tool for the foreseeable future. (orig.) [German] Die Untersuchung der Herzklappen in der MRT umfasst derzeit v. a. die Aorten- und Pulmonalisklappe. Pathologien der atrioventrikulaeren Klappen bilden demgegenueber nur selten die zentrale Fragestellung einer kardialen MRT-Untersuchung, da diese normalerweise einer echokardiographischen Untersuchung gut zugaenglich sind. Die Staerke der MRT ist die hohe Zuverlaessigkeit, mit der neben der Klappenmorphologie und -funktion die Funktionsparameter des jeweiligen Ventrikels und die Morphologie der nachgeschalteten Arterien bestimmt werden koennen. Dadurch kann die MRT die prinzipielle Schwaeche in der Orts- und Zeitaufloesung gegenueber der Echokardiographie teilweise kompensieren. Bei Patienten mit kongenitalen Herzvitien ist die MRT-basierte Klappendiagnostik fester Bestandteil des klinischen Managements. Das gilt besonders fuer die Evaluation der Pulmonalisklappe. Die Echokardiographie bleibt absehbar die Modalitaet der ersten Wahl fuer die Klappendiagnostik am Herzen. (orig.)

  11. Development and validation of a new LBM-MRT hybrid model with enthalpy formulation for melting with natural convection

    Energy Technology Data Exchange (ETDEWEB)

    Miranda Fuentes, Johann [Université de Lyon, CNRS, UMR5008, F-69622 Villeurbanne (France); INSA-Lyon, CETHIL, F-69621 Villeurbanne (France); Kuznik, Frédéric, E-mail: frederic.kuznik@insa-lyon.fr [Université de Lyon, CNRS, UMR5008, F-69622 Villeurbanne (France); INSA-Lyon, CETHIL, F-69621 Villeurbanne (France); Johannes, Kévyn; Virgone, Joseph [Université de Lyon, CNRS, UMR5008, F-69622 Villeurbanne (France); Université Lyon 1, CETHIL, F-69622 Villeurbanne (France)

    2014-01-17

    This article presents a new model to simulate melting with natural convection of a phase change material. For the phase change problem, the enthalpy formulation is used. Energy equation is solved by a finite difference method, whereas the fluid flow is solved by the multiple relaxation time (MRT) lattice Boltzmann method. The model is first verified and validated using the data from the literature. Then, the model is applied to a tall brick filled with a fatty acid eutectic mixture and the results are presented. The main results are (1) the spatial convergence rate is of second order, (2) the new model is validated against data from the literature and (3) the natural convection plays an important role in the melting process of the fatty acid mixture considered in our work.

  12. Muscle injuries in athletes. The value of magnetic resonance imaging; Muskelverletzungen des Sportlers. Stellenwert der MRT-Bildgebung

    Energy Technology Data Exchange (ETDEWEB)

    Lueckerath, C. [Universitaetsklinikum Heidelberg, Abteilung fuer Neuroradiologie, Heidelberg (Germany); Rehnitz, C. [Universitaetsklinikum Heidelberg, Diagnostische und Interventionelle Radiologie, Heidelberg (Germany)

    2017-12-15

    Competitive sports yield high demands on the musculoskeletal system, accordingly muscle injuries are a common complication. Early imaging clarification of the muscles in cases of a trauma is essential in order to define the exact location of the lesion, the affected muscles, the extent and the degree of the injury as well as to define possible concomitant complications. In the case of a professional athlete, the assessment made by MRI is important for defining the individually required resting period for a riskless resumption of the sporting activities. (orig.) [German] Der Leistungssport stellt grosse Anforderungen an den Bewegungsapparat, entsprechend sind muskulaere Verletzungen eine haeufige Komplikation. Eine fruehe bildgebende Darstellung der Muskulatur im Falle eines Traumas ist essenziell, um die Lokalisation, die beteiligten Muskeln, das Ausmass sowie moegliche Komplikationen exakt zu definieren. Im Falle des Profisportlers ist insbesondere die MRT-Stadieneinteilung wichtig fuer die Festlegung der individuell notwendigen Ruhezeit bis zur risikofreien Wiederaufnahme der Aktivitaet. (orig.)

  13. Completion Report for Multi-Site Incentive MRT 2779 Implement ASC Tripod Initiative by 30SEP08

    Energy Technology Data Exchange (ETDEWEB)

    East, D; Cerutti, J; Noe, J; Cupps, K; Loncaric, J; Sturtevant, J

    2008-09-22

    This report provides documentation and evidence for the completion of the deployment of the Tripod common operating system (TripodOS, also known as and generally referred to below as TOSS). Background documents for TOSS are provided in Appendices A and B, including the initial TOSS proposal accepted by ASC HQ and Executives in July 2007 and a Governance Model defined by a Tri-Lab working group in September 2007. Appendix C contains a document that clarifies the intent and requirements for the completion criteria associated with MRT 2779. The deployment of TOSS is a Multi-Site Incentive from the ASC FY08-09 Implementation Plan due at the end of Quarter 4 in FY08.

  14. MRT of the knee joint of juvenile footballers. Are there early changes in the knee due to competitive sport?

    International Nuclear Information System (INIS)

    Wacker, F.; Koenig, H.; Felsenberg, D.; Wolf, K.J.

    1994-01-01

    In a prospective study, the right knee of 21 symptom free juvenile footballers was examined by MRT (group I) and the results were compared with 12 juveniles of similar age but who did not take part in any special sorting activities (group II). A 1.5 Tesla Magnetome with an extremity coil was used. There were no abnormal changes in either group in the cruciate ligaments. The hyaline cartilage medially was about 10% thicker than laterally in both groups but in group I it was, on average, 24.8% thicker than in group II. Increased signals in the centre of the menisci were observed in 8 members of group I and two in group II. 5 on the 8 in group I, but none in group II, also showed an increase in the joint fluid. (orig.) [de

  15. Fetal MRI and ultrasound of congenital CNS anomalies; Fetales MRT und Ultraschall der angeborenen ZNS-Fehlbildungen

    Energy Technology Data Exchange (ETDEWEB)

    Pogledic, I.; Reith, W. [Universitaetsklinikum des Saarlandes, Homburg/Saar, Klinik fuer Diagnostische und Interventionelle Neuroradiologie, Homburg/Saar (Germany); Meyberg-Solomayer, G. [Universitaetsklinikum des Saarlandes, Homburg/Saar, Klinik fuer Frauenheilkunde, Geburtsheilkunde und Reproduktionsmedizin, Homburg/Saar (Germany)

    2013-02-15

    In the last decade the newest technologies, fetal magnetic resonance imaging (MRI) and 3D ultrasound, have given an insight into the minute structures of the fetal brain. However, without knowledge of the basic developmental processes the imaging is futile. Knowledge of fetal neuroanatomy corresponding to the gestational week is necessary in order to recognize pathological structures. Furthermore, a modern neuroradiologist should be acquainted with the three steps in the formation of the cerebral cortex: proliferation, migration and differentiation of neurons in order to be in a position to suspect that there is a pathology and start recognizing and discovering the abnormalities. The fetal MRI has become an important complementary method to ultrasound especially in cortical malformations when confirmation of the prenatal diagnosis is needed and additional pathologies need to be diagnosed. In this manner these two methods help in parental counseling and treatment planning. (orig.) [German] Dank neuer Technologien (z. B. fetale MRT, 3-D-Sonographie) ist es moeglich, kleinste Hirnstrukturen darzustellen. Ohne Kenntnisse der grundlegenden Entwicklungsprozesse des Gehirns waere die Bildgebung jedoch sinnlos. Um pathologische Veraenderungen zu erkennen, ist es notwendig, den Stand der fetalen Neuroanatomie in der entsprechenden Schwangerschaftswoche zu kennen. Heutzutage sollte sich ein Neuroradiologe mit den 3 Schritten der kortikalen Entwicklung - Proliferation, Migration und Differenzierung der Neuronen - vertraut machen. Nur dann wird er in der Lage sein, pathologische Veraenderungen in Betracht zu ziehen, bzw. diese zu erkennen. Die fetale MRT ist besonders wichtig, ergaenzend zur zerebralen Sonographie, zur Diagnosebestaetigung bei kortikalen Veraenderungen und Nachweis weiterer Pathologien. In dieser Kombination ermoeglichen diese Methoden eine adaequate Beratung der Eltern und Planung der Behandlung. (orig.)

  16. Diagnosis and differential diagnosis of Graves' orbitopathy in MRI; Diagnose und Differenzialdiagnose der endokrinen Orbitopathie in der MRT

    Energy Technology Data Exchange (ETDEWEB)

    Daubner, D.; Spieth, S.; Engellandt, K.; Kummer, R. von [Universitaetsklinikum Carl Gustav Carus, Technische Universitaet Dresden, Abteilung Neuroradiologie, Institut und Poliklinik fuer Radiologische Diagnostik, Dresden (Germany)

    2012-06-15

    Imaging of Graves' orbitopathy (GO) includes radiological and nuclear medicine procedures. Depending on the method used they provide information about the distribution and activity of the disease. Magnetic resonance imaging (MRI) is not only a helpful tool for making the diagnosis it also enables differentiation of the active and inactive forms of GO due to intramuscular edema. The modality is therefore appropriate to evaluate the disease activity and the course of therapy. The disease leads to the typical enlargement of the muscle bodies of the extraocular muscles. The inferior rectus, medial rectus and levator palpebrae muscles are mostly involved. Signal changes of the intraconal and extraconal fat tissue are possible and a bilateral manifestation is common. The differential diagnosis includes inflammatory diseases and tumors, of which orbital pseudotumor (idiopathic, unspecific orbital inflammation), ocular myositis and orbital lymphoma are the most important. The specific patterns (localization, involvement of orbital structures and signal changes) can be differentiated by MRI. (orig.) [German] Die Bildgebung der endokrinen Orbitopathie (EO) umfasst radiologische und nuklearmedizinische Verfahren, die je nach Methode Aussagen zur Verteilung und Aktivitaet der Erkrankung liefern. Die Magnetresonanztomographie (MRT) ist nicht nur zur Diagnosestellung hilfreich, sondern auch in der Lage, die aktive von der inaktiven Form anhand des intramuskulaeren Oedems zu unterscheiden. Das Verfahren eignet sich deshalb auch zur Aktivitaetsbeurteilung und zur Bewertung einer Therapie im Verlauf. Die Erkrankung fuehrt zu einer typischen Verdickung des Muskelbauchs der extraokulaeren Augenmuskeln, wobei die Mm. rectus inferior, rectus medialis und levator palpebrae am haeufigsten betroffen sind. Signalveraenderungen des intra- und extrakonalen Fettgewebes sind moeglich, und eine bilaterale Manifestation ist haeufig. Die Differenzialdiagnose umfasst neben anderen

  17. MR-guided preoperative localization and percutaneous core biopsy of suspicious breast lesions - experience on the vertically open 0.5 T system; MRT-gestuetzte Markierung und Stanzbiopsie suspekter Mammalaesionen. Moeglichkeiten und Erfahrungen an einem vertikal offenen 0,5-T-System

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, J.P.; Schulz, T.; Rueger, S.; Schmidt, F.; Kahn, T. [Universitaetsklinikum Leipzig (Germany). Klinik und Poliklinik fuer Diagnostische Radiologie; Horn, L.C. [Inst. fuer Pathologie, Universitaetsklinikum Leipzig (Germany); Leinung, S. [Chirurgische Klinik I, Universitaetsklinikum Leipzig (Germany); Briest, S. [Frauenklinik, Universitaetsklinikum Leipzig (Germany)

    2002-01-01

    ueberfuehren. Patienten und Methode. Initial wurde eine Methode zur Lokalisation bei sitzender Patientin unter Nutzung einer Ringspule entwickelt. Mit diesem Verfahren wurden 31 herdfoermige Laesionen lokalisiert. Weiter erfolgten in Bauchlage 46 Drahtmarkierungen und 28 Stanzbiopsien unter Verwendung einer offenen Brustspule mit integrierter Biopsieeinheit. Ergebnisse. In allen Faellen kontaktierte die Drahtfuehrungsnadel (18 G) bzw. die Koaxialschleuse (14 G) die zu punktierende Laesion (4-25, im Mittel 12 mm). Bei insgesamt 66 benignen und 39 malignen Befunden erwiesen sich die Drahtmarkierungen in 2 Faellen (Befund nach OP unveraendert) und die Stanzbiopsie in einem Fall (Revision des Ergebnisses bei Groessenprogredienz in der Kontrolle) als fehlerhaft. Schlussfolgerungen. Mit Hilfe des fuer Interventionen konzipierten vertikal offenen 0,5-T-MRT koennen sowohl praeoperative Markeirungen als auch perkutane Stanzbiopsien bei MR-suspekten Mammabefunden vorgenommen werden. Dabei kann eine Zuverlaessigkeit erreicht werden, die mit stereotaktisch oder ultraschallgefuehrten Interventionen vergleichbar ist. Kontrollen bei benignen Befunden sind unverzichtbar. (orig.)

  18. [Bewusstes Erinnern und bewusstes Vergessen : der juristische Umgang mit der Vergangenheit in den Ländern Mittel- und Osteuropas / hrsg. v. Angelika Nußberger, Caroline von Gall. (Jus Internationale et Europaeum ; 52). Mohr Siebeck, Tübingen 2011.

    Index Scriptorium Estoniae

    Luts-Sootak, Marju, 1966-

    2014-01-01

    Arvustus: Bewusstes Erinnern und bewusstes Vergessen : der juristische Umgang mit der Vergangenheit in den Ländern Mittel- und Osteuropas / hrsg. v. Angelika Nußberger, Caroline von Gall (Jus Internationale et Europaeum ; 52). Mohr Siebeck, Tübingen 2011. 400 S.

  19. Intraoperative use of an open midfield MR scanner in the surgical treatment of cerebral gliomas; Intraoperative Nutzung eines offenen Mittelfeld-MRT waehrend der chirurgischen Therapie zerebraler Gliome

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, J.P.; Schulz, T.; Dietrich, J.; Kahn, T. [Klinik und Poliklinik fuer Diagnostische Radiologie, Univ. Leipzig (Germany); Trantakis, C. [Klinik und Poliklinik fuer Neurochirurgie, Univ. Leipzig (Germany)

    2003-07-01

    The aim of the present study was to evaluate the effectiveness of intraoperative MRI guidance in achieving more gross-total resection in case of primary brain tumors. We studied 12 patients with low-grade glioma and 19 patients with high-grade glioma who underwent surgery within a vertically open 0.5T MR system. After initial imaging, the resection was stopped at the point in which the neurosurgeon considered the resection complete by viewing the operation field. At this time, intraoperative MRI was repeated (''first control'') to identify any residual tumor. Areas of tumor-suspected tissue were localized and resected, with the exception of tissue adjacent to eloquent areas. Final imaging was carried out before closing the craniotomy. Comparison of ''first control'' and final imaging revealed a decrease of residual tumor volume from 32% to 4.3% in low-grade gliomas, and from 29% to 10% in high-grade gliomas. Intraoperative MRI allows a clear optimization of microsurgical resection of both low-grade and high-grade gliomas. (orig.) [German] Ziel der Untersuchung war es, die Effektivitaet des Einsatzes der intraoperativen MRT bei der Resektion gliogener Hirntumoren zu pruefen. 12 Patienten mit niedriggradigem Gliom und 19 Patienten mit Glioblastom wurden in einem vertikal offenen 0,5-T-MRT operiert. Nach der initialen Bildgebung erfolgte die Resektion bis zu dem Zeitpunkt, an dem der Neurochirurg kein Tumorgewebe mehr im OP-Situs abgrenzen konnte. Zu diesem Zeitpunkt erfolgte eine erneute MRT (''= erste Kontrolle'') zur Visualisierung nur MR-tomographisch darstellbaren Resttumors. Solche Areale wurden im OP-Situs lokalisiert und mit Ausnahme von Strukturen in der Naehe eloquenter Hirnareale reseziert. Vor Verschluss des Schaedels erfolgte eine abschliessende MR-Kontrolle. Durch Einsatz der intraoperativen MRT konnte eine Absenkung des relativen Resttumorvolumens von 32% auf 4,3% bei niediggradigen Gliomen und

  20. MR-Guided vacuum biopsy of 206 contrast-enhancing breast lesions; MRT-gefuehrte Vakuumbiopsie bei 206 Kontrastmittel anreichernden Laesionen der Mamma

    Energy Technology Data Exchange (ETDEWEB)

    Perlet, C.; Schneider, P.; Sittek, H.; Reiser, M.F. [Klinikum der Universitaet Grosshadern, Muenchen (Germany). Inst. fuer Klinische Radiologie; Amaya, B.; Grosse, A.; Heywang-Koebrunner, S.H. [Martin-Luther-Universitaet, Halle (Germany). Klinik fuer Diagnostische Radiologie

    2002-01-01

    Purpose: To determine the accuracy and clinical use of MR-guided vacuum biopsy (VB) of enhancing breast lesions. Material and Methods: 254 lesions were referred to MR-guided vacuum-assisted breast biopsy. In 43 (16%) patients the indication was dropped because the lesions could not be identified at the time VB was scheduled. This was due to hormonal influences (n=37), to too strong compression (n=3) or to misinterpretation of the initial diagnostic MRI. In 5 cases (2%) VB was not performed due to obesity (n=2); problems of access (n=2) or a defect of the MR-unit (n=1). VB was performed on altogether 206 lesions. In 4 cases (2%) VB was unsuccessful. This was immediately realized on the post-interventional images. Thus a false negative diagnosis was avoided. Verification included excision of the cavity in cases with proven malignancy or atypical ductal hyperplasia (ADH) and (for benign lesions) retrospective correlation of VB-histology with pre- and postinterventional MRI and subsequent follow-up. Results: 51/202 successful biopsies proved malignancy. In 7 cases ADH and in 144 cases a benign lesion was diagnosed. One DCIS was underestimated as ADH. All other benign or malignant diagnoses proved to be correct. Conclusion: MR-guided VB allows reliable histological work-up of contrast-enhancing small lesions which are not visible by any other modality. (orig.) [German] Zielsetzung: Evaluation der Wertigkeit und klinischen Anwendbarkeit der MRT-gefuehrten Vakuumbiopsie (VB) bei anreichernden Mammalaesionen. Material und Methoden: Insgesamt wurden 254 Laesionen der MRT-gefuehrten VB zugewiesen. Hiervon entfiel bei 43 Patientinnen (16%) die Biopsieindikation beim Planungs-MRT, da die urspruengliche Anreicherung hormonell (n=37), durch zu starke Kompression (n=3) oder durch eine Fehlinterpretation des vorausgegangenen diagnostischen MRT (n=3) nicht mehr abgrenzbar war. Bei 5 weiteren Laesionen (2%) war die Biopsie nicht moeglich (Adipositas n=2; Zugangsprobleme n=2; MRT

  1. Clinical evaluation of female pelvic tumors. Application fields of integrated PET/MRI; Lokal- und Ganzkoerperdiagnostik weiblicher Beckentumore. Anwendungsfelder der integrierten PET-MRT

    Energy Technology Data Exchange (ETDEWEB)

    Grueneisen, J.; Umutlu, L. [Universitaetsklinikum Essen, Institut fuer diagnostische und interventionelle Radiologie und Neuroradiologie, Essen (Germany)

    2016-07-15

    Integrated positron emission tomography (PET) and magnetic resonance imaging (MRI) scanning has recently become established in clinical imaging. Various studies have demonstrated the great potential of this new hybrid imaging procedure for applications in the field of oncology and the diagnostics of inflammatory processes. With initial studies demonstrating the feasibility and high diagnostic potential of PET/MRI comparable to PET-computed tomography (CT), the focus of future studies should be on the identification of application fields with a potential diagnostic benefit of PET/MRI over other established diagnostic tools. Both MRI and PET/CT are widely used in the diagnostic algorithms for malignancies of the female pelvis. A simultaneous acquisition of PET and MRI data within a single examination provides complementary information which can be used for a more comprehensive evaluation of the primary tumor as well as for whole body staging. Therefore, the aim of this article is to outline potential clinical applications of integrated PET/MRI for the diagnostic work-up of primary or recurrent gynecological neoplasms of the female pelvis. (orig.) [German] Integrierte Positronenemissionstomographie-Magnetresonanztomographen (PET-MRT) stehen seit wenigen Jahren fuer die klinische Diagnostik zur Verfuegung. Diverse Arbeiten konnten bereits das grosse Potenzial dieser neuen hybriden Bildgebungsmodalitaet zur Anwendung in der onkologischen und inflammatorischen Diagnostik aufzeigen. Nachdem initiale Studien die Durchfuehrbarkeit und diagnostische Vergleichbarkeit der PET-MRT zur etablierten PET-Computertomographie (PET-CT) gezeigt haben, sollte fuer eine Implementierung in der Routinediagnostik der Fokus zukuenftiger Studien darin liegen, eindeutige Indikationen zu definieren, in denen die simultane PET-MRT-Bildgebung einen definitiven Vorteil verglichen mit den etablierten diagnostischen Verfahren bietet. Sowohl die MRT als auch die PET-CT finden bereits eine

  2. Natural attenuation at a former gas plant site: isotope analyses; Nachweis von Natural Attenuation mittels Isotopenuntersuchungen an einem ehemaligen Kokereistandort

    Energy Technology Data Exchange (ETDEWEB)

    Nagel, Aglaia; Strauss, Harald; Achten, Christine [Westfaelische Wilhelms-Universitaet Muenster, Institut fuer Geologie und Palaeontologie, Muenster (Germany); Stephan, Manuel [Universitaet Duisburg-Essen, Instrumentelle Analytische Chemie, Essen (Germany)

    2011-12-15

    Natural attenuation of mono- (BTEX) and polycyclic aromatic hydrocarbons (PAHs) was studied in groundwater at a former gas plant site over a distance of about 500 m. The contamination source was located within a 4-6 m thick succession of interbedded silt and sand (K{sub f} =1,4 .10{sup -7} m/s) at a depth of about 5-6 m below the surface. Groundwater flow times between source and the receiving surface waters were determined on the order of a few hundred years. The main contaminants were found to be benzene and naphthalene with concentrations up to 200,000 and 8,500 {mu}g/l, respectively. Over the past 9 years, concentrations within the contaminant plume have decreased and degradation of benzene was proven by compound specific carbon isotope analyses. In addition, sulphur isotope studies revealed that sulphate reduction has played a significant role. This was supported by ambient sulphate concentrations of 300-1,800 {mu}g/l at the site that are sufficient to sustain a long-term perspective for this process. In agreement with these physico-chemical conditions, no transfer of BTEX or PAHs from the plume into the nearby river has been observed. (orig.) [German] An einem ehemaligen Kokereistandort im Ruhrgebiet wurde das Potenzial von Natural Attenuation (natuerlicher Abbau und Rueckhalt) fuer mono- (BTEX) und polyzyklische aromatische Kohlenwasserstoffe (PAK) im Grundwasser auf einer Fliessstrecke von ca. 500 m untersucht. Das Schadenszentrum befindet sich unter eingeebnetem Bergematerial in ca. 5-6 m Tiefe unter Gelaendeoberkante innerhalb einer ca. 4-6 m maechtigen Schluff-Sand-Wechselfolge (K{sub f} =1,4 .10{sup -7} m/s). Im gesamten Aquifer resultieren Fliesszeiten von wenigen Hundert Jahren vom Schadstoffzentrum bis zur Vorflut. Hauptkontaminanten sind Benzen (bis ca. 200.000 {mu}g/l) und Naphthalen (bis ca. 8.500 {mu}g/l). An der Fahnenspitze liegen seit 9 Jahren schrumpfende Konzentrationen vor, die in Einklang mit einem mittels Kohlenstoffisotopie

  3. MRI for therapy planning in patients with atrial septum defects; MRT zur Therapieplanung bei Patienten mit Vorhofseptumdefekt

    Energy Technology Data Exchange (ETDEWEB)

    Huber, A.; Rummeny, E. [Klinikum rechts der Isar, Technische Universitaet Muenchen, Institut fuer Radiologie, Muenchen (Germany); Prompona, M.; Reiser, M.; Theisen, D. [Klinikum der Ludwig-Maximilians-Universitaet Muenchen, Campus Grosshadern, Institut fuer Klinische Radiologie, Muenchen (Germany); Kozlik-Feldmann, R. [Klinikum der Ludwig-Maximilians-Universitaet Muenchen, Campus Grosshadern, Klinik und Poliklinik fuer Kinderkardiologie, Muenchen (Germany); Muehling, O. [Klinikum der Ludwig-Maximilians-Universitaet Muenchen, Campus Grosshadern, Medizinische Klinik I, Muenchen (Germany)

    2011-01-15

    The aim of this study was to determine the value of a combined magnetic resonance imaging (MRI) protocol including steady-state free precession (SSFP) imaging, phase-contrast measurements and contrast-enhanced MR angiography (CE-MRA) for presurgical or preinterventional diagnostic imaging in patients with suspected atrial septum defects. Out of 65 MRI studies of patients with suspected atrial septum defects, 56 patients were included in the study. The atrial septum defects were identified on cine images. Velocity encoded flow measurements were used to determine shunt volumes, which were compared with invasive oxymetry in 24 patients. Contrast-enhanced MRI was used to assess the thoracic vessels in order to detect vascular anomalies. The findings were compared with the intraoperative results. A total of 24 patients with high shunt volumes were treated either surgically (16 patients) or interventionally (8 patients) and 32 patients with low shunt volumes did not require surgical or interventional treatment. The vascular anomaly, which in all cases was anomalous pulmonary venous return, was confirmed by the intraoperative findings. The type and location of atrial septal defects which required treatment, were confirmed intraoperatively or during the intervention. The results of shunt quantification by MRI showed a good correlation with the results of invasive oximetry (r=0.91, p <0.0001). A combined MRI protocol including cine SSFP images, velocity-encoded flow measurements and CE-MRA is an accurate method for preoperative and preinterventional evaluation of atrial septum defects. (orig.) [German] Ziel war es, die Wertigkeit eines kombinierten MRT-Protokolls aus Funktionsuntersuchung, Flussmessung und MR-Angiographie zur praeoperativen oder -interventionellen Abklaerung bei Patienten mit Vorhofseptumdefekt zu evaluieren. Ingesamt wurden 56 Patienten mit Vorhofseptumdefekt aus einem Kollektiv von 65 Patienten mit Verdacht auf Vorhofseptumdefekt, die im MRT untersucht

  4. Early diagnosis of skeletal disorders in childhood and adolescence by MRI; Fruehdiagnose orthopaedischer Erkrankungen des Kindes- und Jugendalters mit der MRT

    Energy Technology Data Exchange (ETDEWEB)

    Meurer, A.; Schwitalle, M.; Engelhardt, O.; Heine, J. [Johannes Gutenberg-Univ. Mainz (Germany). Orthopaedische Klinik und Poliklinik; Kreitner, K.F. [Johannes Gutenberg-Univ. Mainz (Germany). Inst. fuer Klinische Strahlenkunde

    1998-09-18

    The early diagnosis of such disorders is of major importance because, in most cases, severe consequences can only be averted by early treatment. The value of magnetic resonance imaging (MRI) in many orthopaedic and traumatological conditions is generally accepted. The value of MRI in this particular field is illustrated by typical case reports on common clinical problems [Deutsch] Der Fruehdiagnose von Erkrankungen des Kindes- und Jugendalters kommt grosse Bedeutung zu, da oftmals nur durch eine daraus resultierende Fruehbehandlung schwerwiegende Folgen vermieden werden koennen. Die Kernspintomographie (Magnetresonanztomographie=MRT) ist in zahlreichen orthopaedischen-traumatologischen Fragestellungen bereits etabliert. An ausgewaehlten Fallbeispielen haeufiger klinischer Problemstellungen soll in der vorliegenden Arbeit der Stellenwert der MRT dargestellt werden. (orig.)

  5. MRI of the musculature in patients with myalgia - indications and imaging results; MRT der Muskulatur bei Myalgien - Indikationen und Bildbefunde

    Energy Technology Data Exchange (ETDEWEB)

    Beese, M.S. [Universitaetsklinik Hamburg-Eppendorf (Germany). Radiologische Klinik; Winkler, G. [Universitaetsklinik Hamburg-Eppendorf (Germany). Neurologische Klinik; Maas, R. [Universitaetsklinik Hamburg-Eppendorf (Germany). Radiologische Klinik; Buechler, E. [Universitaetsklinik Hamburg-Eppendorf (Germany). Radiologische Klinik

    1996-05-01

    241 patients suffering from myalgic symptoms were examined by axial scans of the muscular system with T1w and STIR-sequences. All patients underwent a complete neuromuscular examination, which included an MRI guided muscle-biopsy of 203 patients. The images were retrospectively analysed as to the typical characteristics of differential diagnosis. In cases of idiopathic or bacterial/viral induced myositis, primary vasculitis, and rhabdomyolysis, edematous changes of the muscles could always be found. Abscesses were only found in bacterial myositis. In cases of poly- and dermatomyositis as well as inclusion-body-myositis, MRI showed a uniform distribution pattern with emphasis on the quadriceps muscles. In contrast to other neuromuscular diseases in bacterial induced myositis, focal myositis, and rhabdomyolysis a strong contrast agent enhancement was seen. All patients with myalgic syndromes without any other additional neuropathological findings and 86% of the patients suffering from polymyalgia rheumatica had normal MR-findings. MRI allows a correct exclusion of an inflammatory, tumorous, or rhabdomyolitic cause of a myalgia and leads to pathognomonic findings for these diseases. Diseases belonging to the group of endocrine, toxic, or metabolic myopathies might be normal in MRI. (orig./MG) [Deutsch] Bei 241 Patienten mit myalgischen Beschwerden wurden axiale Aufnahmen der Muskulatur mit T1w- und STIR-Sequenzen angefertigt. Bei allen Patienten wurde eine vollstaendige neuromuskulaere Untersuchung durchgefuehrt, die bei 203 Patienten eine MRT-gezielte Muskelbiopsie beinhaltete. Das Bildmaterial wurde retrospektiv hinsichtlich differentialdiagnostischer Charakteristika analysiert. Bei idiopathischen und erregerbedingten Myositiden, primaeren Vaskulitiden und bei Rhabdomyolysen bestanden ohne Ausnahme oedematoese Veraenderungen der Muskulatur. Abszessformationen wurden nur bei erregerbedingten Myositiden vorgefunden. Bei Poly- und Dermatomyositiden sowie

  6. Precision of MR-guided needle placement. Experimental results; Praezision der Lokalisierbarkeit einer Punktionsnadel in der MRT. Experimentelle Ergebnisse

    Energy Technology Data Exchange (ETDEWEB)

    Langen, H.J. [Roentgenabteilung der Missionsaerztlichen Klinik Wuerzburg (Germany); Stuetzer, H. [Inst. fuer Medizinische Statistik, Informatik und Epidemiologie der Univ. zu Koeln (Germany); Kugel, H.; Krug, B.; Hesselmann, V.; Schulte, O.; Walter, C.; Landwehr, P. [Inst. und Poliklinik fuer Radiologische Diagnostik der Univ. zu Koeln (Germany)

    2000-11-01

    -Geraet mit Turbo-Spin-Echo (TSE)- und Gradienten-Echo (FFE)-Sequenzen von 20 s bzw. 40 s Dauer in 34 unterschiedlichen Orientierungen der Nadel zu B{sub 0} Frequenzkodier- und Schichtselektionsgradienten dargestellt. 4 in der Beurteilung von Nadelartefakten unerfahrene Untersucher schaetzten unabhaengig voneinander die Positionen der Nadelspitze anhand der Artefakte ab. Die Nadelpositionen wurden vor und nach einer 15minuetigen Einweisung bestimmt, in der anhand von hochaufloesenden MR-Bildern Groesse und Form der Artfakte erklaert wurden, die bei den 12 moeglichen Kombinationen von parallelen oder rechtwinkligen Anordnungen der Nadeln zu B{sub 0} und zum Frequenzkodiergradienten auftreten. Die vor und nach der Einweisung bestimmten Positionen wurden mit den tatsaechlichen Nadelpositionen verglichen. Ergebnisse: Die Laenge der Nadel wurde in den TSE-Bildem im Mittel um 1,8{+-}2,3 mm, in den FFE-Bildern um 2,5{+-}1,2 mm ueberschaetzt. Nach der Uebung nahm der Fehler signifikant auf 0,2{+-}1,8 mm fuer die TSE-Bilder und auf 1,0{+-}1,8 mm fuer die FFE-Bilder ab. Die Lokalisation der Nadelspitze gelang in den TSE-Sequenzen im Mittel mit einer hoeheren Praezision. Schlussfolgerung: Bei MR-gesteuerter Biopsie unter Verwendung von FFE- und TSE-Sequenzen kann die Nadelposition praeziser bestimmt werden, wenn der Untersucher mit den Artefaktformen vertraut ist, die bei den 12 moeglichen rechtwinkligen oder parallelen Orientierungen der Nadel zu B{sub 0} und Frequenzkodiergradienten entstehen. (orig.)

  7. Optimized detection and characterization of liver metastases. The role of current MRI contrast agents; Optimierte Detektion und Charakterisierung von Lebermetastasen. Leistungsvermoegen aktueller MRT-Kontrastmittel

    Energy Technology Data Exchange (ETDEWEB)

    Weinrich, J.M.; Well, L.; Bannas, P. [Universitaetsklinikum Hamburg-Eppendorf, Zentrum fuer Radiologie und Endoskopie, Klinik und Poliklinik fuer diagnostische und interventionelle Radiologie und Nuklearmedizin, Hamburg (Germany)

    2017-05-15

    Metastases are the most common malignant lesions of the liver. The presence of liver metastases is an important prognostic factor and is decisive for the further management, especially in patients with colorectal cancer. Detection and characterization of liver metastases as well as differentiation from benign lesions are of high importance and a daily challenge in clinical radiology. Contrast-enhanced magnetic resonance imaging (MRI) has the highest sensitivity in detecting liver metastases. The sensitivity of MRI has been further increased due to the development of liver-specific contrast agents. This article describes the role of extracellular and hepatobiliary contrast agents for the detection and characterization of liver metastases. Moreover, the current knowledge on safety, sequence optimization, transient severe dyspnea and the combination of hepatobiliary with intravascular contrast agents for liver imaging is discussed. (orig.) [German] Metastasen sind die haeufigsten malignen Leberlaesionen. Das Vorhandensein von Lebermetastasen ist entscheidend fuer die Prognose und weitere Therapieplanung von Tumorpatienten, insbesondere von Patienten mit kolorektalen Karzinomen. Die Detektion von Lebermetastasen sowie deren Unterscheidung von anderen Leberlaesionen sind daher von hoechster Bedeutung und stellen eine alltaegliche Herausforderung fuer den Radiologen dar. Die Bildgebung mit der hoechsten Sensitivitaet fuer die Detektion von Lebermetastasen stellt die dynamische kontrastmittelgestuetzte Magnetresonanztomographie (MRT) dar. Die bereits hohe Sensitivitaet der MRT wird durch den Einsatz leberspezifischer Kontrastmittel noch weiter gesteigert. Dieser Artikel beleuchtet die Rolle der aktuellen unspezifischen und leberspezifischen MRT-Kontrastmittel fuer die Detektion und Charakterisierung von Lebermetastasen. Weiterhin werden Erkenntnisse zur Sicherheit, Sequenzoptimierung, zu transienten Atemartefakten und zur Kombination von MRT-Kontrastmitteln fuer die

  8. Epiphyseal injuries of the distal tibia. Does MRI provide useful additional information?; Epiphysenfugenverletzungen der distalen Tibia. Sinnvolle Mehrinformation durch die MRT?

    Energy Technology Data Exchange (ETDEWEB)

    Iwinska-Zelder, J.; Schmidt, S.; Ishaque, N.; Klose, K.J.; Hoppe, M. [Marburg Univ. (Germany). Abt. fuer Strahlendiagnostik; Schmitt, J.; Gotzen, L. [Marburg Univ. (Germany). Medizinisches Zentrum fuer Operative Medizin

    1999-01-01

    Plain film radiography often underestimates the extent of injury in children with epiphyseal fracture. Especially Salter-Harris V fractures (crush fracture of the epiphyseal plate) are often primarily not detected. MRI of the ankle was performed in 10 children aged 9-17 (mean 14) years with suspected epiphyseal injury using 1.0-T Magnetom Expert. The fractures were classified according to the Salter-Harris-Rang-Odgen classification and compared with the results of plain radiography. In one case MRI could exclude epiphyseal injury; in four cases the MRI findings changed the therapeutic management. The visualisation of the fracture in three orthogonal planes and the possibility of detection of cartilage and ligamentous injury in MR imaging makes this method superior to conventional radiography and CT. With respect to radiation exposure MRI instead of CT should be used for the diagnosis of epiphyseal injuries in children. (orig.) [Deutsch] Die konventionelle Roentgendiagnostik unterschaetzt haeufig das Ausmass der kindlichen Extremitaetenfrakturen mit Epiphysenbeteiligung (Typ Salter-Harris). Insbesondere werden die Kompressionsfrakturen der Wachstumsfuge (Salter-Harris V) primaer haeufig nicht erkannt. Prospektiv wurden 10 Kinder im Alter von 9-17 Jahren (Durchschnittsalter = 14 J.) mit Verdacht auf eine epiphysaere Fraktur der distalen Tibia magnetresonanztomographisch (1.0-Tesla Magnetom Expert), untersucht. Die MRT-Ergebnisse wurden auf der Basis der Klassifikation nach Salter-Harris-Rang-Odgen mit den konventionellen Roentgenbildern verglichen. In einem Fall, bei einem 15jaehrigen Patienten, gelang durch die MRT der Ausschluss einer epiphysaeren Verletzung. In 7 Faellen fuehrte der MRT-Einsatz zu einer Aenderung der Klassifikation nach Salter-Harris. Hieraus resultierte bei 4 Patienten ein Therapiewechsel. Da Frakturen, die sie begleitenden Knorpellaesionen und ligamentaere Verletzungen multiplanar dargestellt werden koennen, weist die MRT deutliche Vorteile

  9. New aspects from legislation, guidelines and safety standards for MRI; Neues aus Gesetzen, Richtlinien und Sicherheitsstandards fuer die MRT

    Energy Technology Data Exchange (ETDEWEB)

    Muehlenweg, M. [Krankenhaus Martha-Maria Halle-Doelau, Institut fuer Radiologie, Halle (Saale) (Germany); Schaefers, G. [MR:comp GmbH, Gelsenkirchen (Germany); Trattnig, S. [Exzellenzzentrum Hochfeld-Magnetresonanz, Medizinische Universitaet Wien, Universitaetsklinik fuer Radiodiagnostik, Wien (Austria)

    2015-08-15

    Betriebsanleitung der MR-Scanner. Die verpflichtenden Inhalte der Betriebsanleitung werden in einer zentralen Norm der International Electrotechnical Commission (IEC) 60601-2-33 geregelt. In dieser Norm wurde juengst die Anwendung statischer Magnetfelder in der MRT bis zu 8 Tesla (T) in der klinischen Routine (kontrollierte Betriebsart 1. Stufe) zugelassen. Die ebenfalls notwendige CE-Zertifizierung der Ultrahochfeldscanner (7-8 T) in Europa ist fuer zukuenftige Geraete zu erwarten. Bestehende Installationen werden nicht automatisch zertifiziert, sondern behalten ihren experimentellen Status. Die aktuelle Erweiterung der IEC 60601-2-33 fuehrt eine neue Zusatzoption, die sog. ''fixed parameter option'' (FPO) ein. Diese Option kann zusaetzlich zu den etablierten Betriebsarten geschaltet werden und definiert eine fixe Geraetekonstellation und bestimmte Parameter des Energieoutputs von MR-Scannern, die zukuenftig die Untersuchungen von Implantatpatienten vereinfachen soll. Die Beschaeftigung schwangerer Mitarbeiterinnen in einer MRT-Einrichtung ist nach wie vor nicht allgemein in Europa geregelt. In Deutschland und Oesterreich wurden 2014 in Teilregionen Beschaeftigungsverbote fuer Schwangere und Stillende im der MR-Kontrollzone (0,5 mT) erteilt. Zugrunde liegt die meist ungeklaerte Frage der Anwendbarkeit von Grenzwerten fuer Beschaeftigte (Extremitaetenexposition fuer statische Magnetfelder bis 8 T erlaubt) oder der Grenzwerte fuer die Allgemeinbevoelkerung (maximal bis 400 mT). Das Verwerfen von Muttermilch nach i.v.-Gabe von gadoliniumhaltigen Kontrastmitteln bei einer stillenden Frau wird laut Gesellschaft fuer urogenitale Radiologie (ESUR) nur noch bei Gabe von Kontrastmitteln der Nephrogenic-systemic-fibrosis(NSF)-Hochrisikoklasse empfohlen. (orig.)

  10. Mediastinal fibrosis with pulmonary artery obstruction; diagnosis and investigation with helical CT imaging including 3-dimensional reconstructions; Pulomonalarterienstenose bei aggresiver Mediastinalfibrose; Diagnostik und 3D-Darstellung mittels helikaler CT-Untersuchung

    Energy Technology Data Exchange (ETDEWEB)

    Kolbe, M. [Inst. fuer Diagnostische Radiologie, Kantonsspital Basel (Switzerland); Helwig, A. [Inst. fuer Diagnostische Radiologie, Kantonsspital Basel (Switzerland); Habicht, J.M. [Klinik fuer Herz-Torax-Chirurgie, Universitaetskliniken Basel (Switzerland); Steinbruch, W. [Inst. fuer Diagnostische Radiologie, Kantonsspital Basel (Switzerland)

    1997-07-01

    An aggressive mediastinal fibrosis was found in a 42-year-old female, suffering from dysphagia, stabbing pain in the chest, and an unclear weight loss. In this case, the rare combination of esophageal involvement, bronchial narrowing, and pulmonary artery obstruction could easily be demonstrated with a barium study and a helical CT examination including three-dimensional reconstructions. (orig.) [Deutsch] Wir stellen den Fall einer 42jaehrigen Patientin vor, welche zur Abklaerung einer zunehmenden Dysphagie, stechender Thoraxschmerzen und eines Gewichtsverlustes hospitalisiert wurde. Mittels klinischer und radiologischer Abklaerung konnte eine aggressive Mediastinalfibrose diagnostiziert werden. Die seltene Kombination einer Oesophaguseinengung mit Pulmonalarterienstenosen sowie einer Bronchuskompression konnte nichtinvasiv mittels Oesophagogramm und helikaler CT-Untersuchung zuverlaessig und schnell dargestellt werden. (orig.)

  11. Accuracy of renal volume assessment in children by three-dimensional sonography; Nierenvolumetrie im Kindesalter: Genauigkeit der dreidimensionalen Sonographie im Vergleich zur konventionellen Sonographie und CT/MRT

    Energy Technology Data Exchange (ETDEWEB)

    Fritz, G.A.; Riccabona, M.; Bohdal, G. [Klinik fuer Radiologie, Universitaetsklinikum Graz (Austria); Quehenberger, F. [Inst. fuer medizinische Informatik, Statistik und Dokumentation, Universitaetsklinikum Graz (Austria)

    2003-04-01

    Purpose: Prospective evaluation of the accuracy of three-dimensional ultrasound (3DUS) to assess the renal parenchymal volume. Materials and Methods: CT, MRI, 2DUS and 3DUS were used to measure the renal volume in 40 patients (range: neonate to 17 years; mean age: 8.95 years). The 3DUS was determined with a Voluson 730 (Kretztechnik, GE) or an external 3D-system (EchoTech, GE) using electromagnetic positioning sensors attached to conventional 2DUS-equipment. The 2DUS volume was calculated with the ellipsoid equation and the 3DUS volume computed with the system integrated software. For CT and MRI, planimetric analysis was used to determine the renal parenchymal volume, whereby the dilated collecting system of a hydronephrosis was subtracted to obtain the real renal parenchymal volume. The results of 2DUS and 3DUS were compared to the results of CT and MRI, and inter- and intraobserver variabilities were calculated. Results: In 74 of 77 kidneys, the 3DUS study was of diagnostic quality. The accuracy of the 3DUS volumes compared well to the CT and MRI volumes with a mean difference of -1.8 {+-} 4.6% versus a mean difference of -2.4 {+-} 15.4% for 2DUS. In normal kidneys, the accuracy was -2.6 {+-} 4.4% for 3DUS and -3.8 {+-} 14.7% for 2DUS. In hydronephrosis, the accuracy was +4.0 {+-} 5.9% and +9.6 {+-} 21.3%, respectively, indicating that 3DUS is more accurate than 2DUS, particularly in kidneys with a dilated collecting system. Inter- and intraobserver variabilities were {+-} 7.3% and {+-} 5.3%. Conclusion: For assessing the renal parenchymal volume in children, 3DUS is feasible and comparable to CT and MRI. (orig.) [German] Studienziel: Prospektive Evaluation der Genauigkeit des drei-dimensionalen Ultraschalls (3DUS) bei der Volumetrie der kindlichen Niere im Vergleich zur CT/MRT. Methode: Bei 40 Patienten (Alter: 0 - 17 Jahre) mit einer klinisch indizierten CT/MRT des Abdomens oder des Harntrakts wurde zusaetzlich ein 2D- und 3DUS inklusive Volumetrie des

  12. MRI for therapy control in patients with tetralogy of Fallot; MRT zur Therapiekontrolle bei Patienten mit Fallot-Tetralogie

    Energy Technology Data Exchange (ETDEWEB)

    Theisen, D.; Reiser, M.F. [Klinikum der Ludwig-Maximilians-Universitaet Muenchen, Campus Grosshadern, Institut fuer Klinische Radiologie, Muenchen (Germany); Dalla Pozza, R.D. [Klinikum der Ludwig-Maximilians-Universitaet Muenchen, Campus Grosshadern, Abteilung fuer Kinderkardiologie und Paediatrische Intensivmedizin, Kinderherzzentrum, Muenchen (Germany); Malec, E. [Klinikum der Ludwig-Maximilians-Universitaet Muenchen, Campus Grosshadern, Herzchirurgische Klinik, Kinderherzzentrum, Muenchen (Germany)

    2011-01-15

    With prevalences ranging from 0.26 to 0.8 permille of all live births tetralogy of Fallot (TOF) is the most common congenital heart disease with primary cyanosis. Due to improvements in surgical techniques, nearly all patients can nowadays expect to reach adulthood. After surgical repair, pulmonary regurgitation (PR) occurs in almost every child and is an important contributing factor in long-term morbidity and mortality. Cardiac magnetic resonance imaging is well established for functional assessment and flow measurements and is an ideal tool for serial post-surgical follow-up examinations, as it is non-invasive and does not expose patients to ionizing radiation. The timing of pulmonary valve replacement is crucial as right ventricular (RV) volumes have only proven to normalize when preoperative end-diastolic volumes are <170 ml/m{sup 2} and end-systolic volumes are <85 ml/m{sup 2}. After surgical repair up to 15% of patients have residual or recurrent pulmonary artery stenosis. Distal pulmonary branch stenosis can aggravate PR and lead to right heart failure due to combined pressure and volume overload. Therefore, it has to be diagnosed in time and treated by angioplasty with or without stenting. (orig.) [German] Die Fallot-Tetralogie (TOF) ist mit einer Praevalenz zwischen 0,26 und 0,8 permille aller Lebendgeburten der haeufigste Herzfehler mit primaerer Zyanose. Durch verbesserte Operationstechniken erreichen heute nahezu alle Patienten das Erwachsenenalter. Bei fast allen Patienten tritt eine postoperative Pulmonalinsuffizienz (PI) auf, die entscheidenden Einfluss auf die langfristige Morbiditaet und Mortalitaet hat. Die kardiale Magnetresonanztomographie (MRT) ist fuer Quantifizierung von Ventrikelfunktion und Klappeninsuffizienzen etabliert und aufgrund ihrer fehlenden Invasivitaet und Strahlenexposition sehr gut fuer regelmaessige Verlaufskontrollen der heranwachsenden Patienten geeignet. Insbesondere der Zeitpunkt fuer einen Pulmonalklappenersatz darf

  13. Functional magnetic resonance imaging for evaluation of radiation-induced renal damage; Funktionelle MRT der Niere zur Erfassung strahleninduzierter Nierenschaedigungen

    Energy Technology Data Exchange (ETDEWEB)

    Haneder, S.; Schoenberg, S.O.; Michaely, H.J. [Universitaetsmedizin Mannheim, Medizinische Fakultaet Mannheim der Universitaet Heidelberg, Institut fuer Klinische Radiologie und Nuklearmedizin, Mannheim (Germany); Boda-Heggemann, J. [Universitaetsmedizin Mannheim, Medizinische Fakultaet Mannheim der Universitaet Heidelberg, Klinik fuer Strahlentherapie und Radioonkologie, Mannheim (Germany)

    2012-03-15

    The diagnosis of radiation-induced (especially chronic) renal alterations/damage is difficult and currently relies primarily on clinical evaluation. The importance of renal diagnostic evaluation will increase continuously due to the increasing number of long-term survivors after radiotherapy. This article evaluates the potentia diagnostic contribution of magnetic resonance (MR) imaging with a focus on functional MRI. The following functional MRI approaches are briefly presented and evaluated: blood oxygenation level-dependent imaging (BOLD), diffusion-weighted imaging (DWI) or diffusion tensor imaging (DTI), MR perfusion measurements and {sup 23}Na imaging. In summary, only DWI and contrast-enhanced MR perfusion currently seem to be suitable approaches for a broader, clinical implementation. However, up to now valid data from larger patient studies are lacking for both techniques in regard to radiation-induced renal alterations. The BOLD and {sup 23}Na imaging procedures have a huge potential but are currently neither sufficiently evaluated with regard to radiation-induced renal alterations nor technically simple and reliable for implementation into the clinical routine. (orig.) [German] Die Diagnostik strahleninduzierter, insbesondere chronischer Schaedigungen der Niere ist nach wie vor schwierig und beruht primaer auf der klinischen Beurteilung. Durch die zunehmende Anzahl von Langzeitueberlebenden nach einer Strahlentherapie wird die Bedeutung dieser Diagnostik jedoch weiter zunehmen. In diesem Beitrag wird der Frage nachgegangen, in wieweit hierzu die MRT-Bildgebung und hier besonders die funktionellen Bildgebungsmodalitaeten ihren Beitrag leisten koennen. Die folgenden Verfahren werden kurz vorgestellt und bewertet: die Blood-oxygenation-level-dependent-Bildgebung (BOLD), die diffusionsgewichtete Bildgebung (''diffusion-weighted imaging'', DWI) bzw. das ''diffusion tensor imaging'' (DTI), die MR-Perfusionsmessungen, und

  14. MRI of the hyaline knee joint cartilage. Animal experimental and clinical studies; MRT des hyalinen Kniegelenkknorpels. Tierexperimentelle und klinische Untersuchungen

    Energy Technology Data Exchange (ETDEWEB)

    Adam, G. [Technische Hochschule Aachen (Germany). Klinik fuer Radiologische Diagnostik; Prescher, A. [Technische Hochschule Aachen (Germany). Inst. fuer Anatomie; Nolte-Ernsting, C. [Technische Hochschule Aachen (Germany). Klinik fuer Radiologische Diagnostik; Buehne, M. [Technische Hochschule Aachen (Germany). Klinik fuer Radiologische Diagnostik; Scherer, K. [Technische Hochschule Aachen (Germany). Inst. fuer Versuchstierkunde; Kuepper, W. [Technische Hochschule Aachen (Germany). Inst. fuer Versuchstierkunde; Guenther, R.W. [Technische Hochschule Aachen (Germany). Klinik fuer Radiologische Diagnostik

    1994-02-01

    The value of MR imaging for the detection of hyaline cartilage lesions using 2-D spin-echo and 3-D gradient-echo imaging was evaluated in an animal experiment in 10 dogs and in a clinical study in 30 patients. MR imaging findings were compared with histopathological and arthroscopy findings, respectively. Using MRI neither grade I nor grade II hyaline cartilage lesions were detectable. In the animal experiments 77% of grade III lesions and all the grade IV lesions were seen. However, in the clinical study only about the half of grade III and IV lesions were detected. 3-D gradient-echo MR imaging was superior to 2-D spin-echo imaging (p<0.001), while 3-D FLASH and 3-D FISP did not differ significantly in the detection rate (p<0.34). 3-D gradient-echo MR imaging seems to be the best method for the delineation of high grade cartilage lesions. However, early stages of cartilage degeneration are invisible even with this imaging modality. (orig.) [Deutsch] Die Wertigkeit der MRT in der Erfassung von Knorpellaesionen mit 2-D-Spin-Echo- und 3-D-Grafienten-Echo-Sequenzen wurde in einer tierexperimentellen Untersuchung an 10 Hunden sowie in einer klinischen Studie an 30 Patienten ueberprueft. Die kernspintomographischen Ergebnisse wurden mit dem pathologisch-anatomischen Befund bzw. der Arthroskopie verglichen. MR-tomographisch konnten weder Grad-I- noch Grad-II-Knorpellaesionen erfasst werden. Die Erkennbarkeitsrate der Grad-III- und -IV-Laesionen lag fuer die tierexperimentellen Untersuchungen bei 77 bzw. 100%, waehrend klinisch nur etwa 50% dieser Veraenderungen erkannt werden konnten. Dabei waren die 3-D-Gradienten-Echo-Sequenzen den 2-D-Spin-Echo-Sequenzen signifikant ueberlegen (p<0,001), waehrend sich die 3-D-Gradienten-Echo-Sequenzen FISP und FLASH nicht voneinander unterschieden (p<0,34). Derzeit muessen die 3-D-Gradienten-Echo-Sequenzen als die beste Methode zur Erfassung hoehergradiger Knorpellaesionen angesehen werden. Fruehe Stadien der Knorpelschaedigung sind

  15. Animal experimental studies on the influence of fatty infiltration of the liver on tissue relaxation times and signal changes in MRT

    International Nuclear Information System (INIS)

    Kreft, B.; Stark, D.; Schild, H.

    1995-01-01

    Using a spectrometer (n=60) in vitro and MRT imaging (n=8) in vivo, we studied the influence of fatty changes of liver cells on the relaxation times of the liver (two animal models of fatty liver disease/orotic acid, L-ethionine). Induction of fatty degeneration of the liver by means of an orotic acid diet resulted in pure deposition of fat in the liver without any histological or serological proof of inflammatory changes. Although accumulation of triglyceride in the liver reduced the T 1 relaxation time only relatively slightly (-15%), there was good correlation (r=0.88) between fat content and T 1 . There was also good correlation (r=0.92) between T 2 and histological fat content. Inflammatory changes besides fatty deposition were seen both serologically and histologically in the L-ethionine model, so that the fatty content did not correlate with T 1 . In-vivo MRT imaging showed that spin-echo sequences are inappropriate for diagnosing fatty infiltration of the liver despite the relaxation time changes produced by the fatty deposition. On the other hand, chemical-shift imaging sequences are very sensitive to identify fatty deposits, and are also independent of any additionally existing inflammatory changes. (orig.) [de

  16. Fetal MRI; Fetales MRT

    Energy Technology Data Exchange (ETDEWEB)

    Blondin, D. [Inst. fuer Diagn. Radiologie, Uniklinikum Duesseldorf (Germany); Turowski, B. [Inst. fuer Diagn. Radiologie, Neuroradiologie, Uniklinikum Duesseldorf (Germany); Schaper, J. [Inst. fuer Diagn. Radiologie, Kinderradiologie, Uniklinikum Duesseldorf (Germany)

    2007-02-15

    Ultrasonography is the method of choice for prenatal malformation screening, but it does not always provide sufficient information for correct diagnosis or adequate abnormality evaluation. Fetal MRI is increasingly being used to complete sonographic findings. It was initially used for evaluation of cerebral abnormalities but is increasingly being applied to other fetal areas. In vivo investigation of fetal brain maturation has been enhanced by MRI. An adequate analysis of fetal chest and abdomen can be achieved with fast T2-, T1-weighted and diffusion-weighted imaging (DWI). The advantages include the great field of view and the excellent soft tissue contrast. This allows correct diagnosis of congenital diaphragmatic hernia and evaluation of the consequences on pulmonary growth. Other pulmonary malformations, such as cystic adenomatoid malformation, sequestration and brochogenic cysts, can also be easily identified. Renal position can be quickly determined using DWI sequences and renal agenesia can be easily diagnosed with only one sequence. Prenatal MRI is virtually as effective as postnatal examination, dispenses with transport of a potentially very ill newborn, and provides logistic advantages. Therefore, prenatal MRI is useful for adequate postnatal treatment of newborns with malformations. (orig.)

  17. Operation planning for a pondage power station chain by means of linear programming and genetic optimisation; Einsatzplanung fuer eine Flusskraftwerkskette im Schwellbetrieb mittels LP und genetischer Optimierung

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, H.; Huelsemann, M.

    1997-12-31

    This paper presents a system package which serves as a simulation and optimisation tool for daily operation planning for a hydroelectric cascade. The purpose of the planning is to maximise (the differentially weighted) production of electrical energy given a certain set of specifications and secondary conditions. Optimal operation management is achieved using a two-stage approach: first pre-optimisation by means of linear programming, followed by detail optimisation using a Genetic Algorithm based on a non-linear, dynamic model of the power station and reservoir chain. [Deutsch] Im Beitrag wird ein Systempaket als Simulations- und Optimierungswerkzeug zur taeglichen Betriebsplanung einer Wasserkraftwerkskaskade vorgestellt. Ziel der Wasserbewirtschaftung ist es, unter den gegebenen Vorgaben und Randbedingungen die (bewertete) Erzeugung elektrischer Energie zu maximieren. Das optimale Fahrplanmanagement wird durch einen zweistufigen Loesungsansatz realisiert: Mit einer Vor-Optimierung mittels Linearer Programmierung (LP), gefolgt von einer detaillierten Optimierung mit einem Genetischen Algorithmus, der auf ein nichtlineares, dynamisches Simulationsmodell fuer die Kette aus Kraftwerken und Stauraeumen zugreift. (orig./RHM)

  18. Measurement of the filling height of transient two-phase surge flows in pipelines by means of electronics; Messung der Fuellhoehe von transienten Zweiphasenschwallstroemungen in Rohrleitungen mittels Ultraschall

    Energy Technology Data Exchange (ETDEWEB)

    Hofmann, B.; Rockstroh, M. [Technische Univ. Dresden (Germany). Inst. fuer Energiemaschinen und Maschinenlabor

    1997-12-01

    The aim of the ultrasonic measurements was the determination of the time course of the level of a transient surge flow with swirl and waves in partly filled roughly horizontally laid pipelines. The running time of the ultrasonic waves from the test head to the liquid surface and back was measured for this purpose. The course of the stress was recorded digitally and was evaluated with the aid of software. Waves, swirl, turbulence of flow and introduced test bodies in the flow caused typical echoes, which had to be taken into account in the evaluation. As the test head was fitted on the outside of the pipe (clamp-on technique), the pipe wall thickness and the speed of sound in the pipe wall had to be included in the calculation of filling height by means of a correction. [Deutsch] Ziel der Ultraschallmessungen war die Bestimmung des zeitlichen Verlaufes der Fuellhoehe einer transienten, drall- und wellenbehafteten Schwallstroemung in teilgefuellten, etwa horizontal verlegten Rohrleitungen. Hierzu wurde die Laufzeit der Ultraschallwellen vom Pruefkopf zur Fluessigkeitsoberflaeche und zurueck gemessen. Die Laufzeit der Ultraschallwellen wurde auf eine quasi-analog elektrische Spannung abgebildet. Der Spannungsverlauf wurde digital aufgezeichnet und softwaregestuetzt ausgewertet. Wellen, Drall, Stroemungsturbulenzen sowie eingebrachte Pruefkoerper in der Stroemung hatten typische Echoerscheinungen zur Folge, die bei der Auswertung zu beruecksichtigen waren. Da der Pruefkopf aussen am Rohr angebracht war (clamp-on-Technik), musste die Rohrwandstaerke und die Schallgeschwindigkeit in der Rohrwandung mittels eines Korrekturgliedes in die Fuellhoehenberechnung eingezogen werden. (orig.)

  19. The significance of diagnostic MRI for visualisation of trauma-induced cervical nerve root avulsion. Case report; Die Bedeutung der MRT-Diagnostik zur Darstellung traumatisch bedingter zervikaler Wurzelausrisse. Kasuistik

    Energy Technology Data Exchange (ETDEWEB)

    Muth, C P [Carl-Thiem-Klinikum, Cottbus (Germany). Inst. fuer Radiologie; Biemelt, F [Carl-Thiem-Klinikum, Cottbus (Germany). Inst. fuer Radiologie; Kamenz, M [Carl-Thiem-Klinikum, Cottbus (Germany). Inst. fuer Radiologie

    1996-11-01

    The article is intended to show the value of MRI for diagnostic visualisation and evaluation of posttraumatic nerve root avulsion as a brachial plexus injury. (orig./MG) [Deutsch] Das Ziel der Arbeit besteht in der Darstellung des Wertes der MRT-Diagnostik bei der Abklaerung traumatischer Wurzelausrisse im Bereich des Plexus brachialis. (orig./MG)

  20. C-arm computed tomography for transarterial chemoperfusion and chemo-embolization of thoracic lesions; Transarterielle Chemoperfusion und -embolisation thorakaler Neoplasmen mittels C-Arm CT

    Energy Technology Data Exchange (ETDEWEB)

    Vogl, T.J.; Naguib, N.N.; Nour-Eldin, N.E.; Lehnert, T.; Mbalisike, E. [Klinikum der Johann-Wolfgang-Goethe-Universitaet, Institut fuer Diagnostische und Interventionelle Radiologie, Frankfurt am Main (Germany)

    2009-09-15

    To evaluate the role of C-arm CT for on-line fluoroscopy in regional transarterial chemoperfusion (TACP) and chemo-embolization (TPCE) of primary and secondary malignant thoracic lesions. From September 2008 to March 2009 a total of 31 patients (20 males and 11 females, average age: 61.7 years, range 22-84 years) with 53 thoracic malignant lesions from different origins (primary or secondary pulmonary carcinoma n=37, pleural mesothelioma n=16) were treated with TACP or TPCE using flat-detector CT (FD-CT). C-arm CT of the latest generation was used to localize the lesion before local chemotherapy (Artis Zeego, Siemens, Erlangen). For TACP a 220 rotation and a volume of 150 ml (ratio of 1:2 contrast/normal saline), delay 2 s and flow 12 ml/s was used. For TPCE a volume of 75 ml (ratio of 1:2 contrast/normal saline), delay 2 s and flow 3 ml/s was used. TPCE C-arm CT allowed the evaluation of the degree of perfusion of the tumor and the geographic areas of enhancement correlated with the post-interventional lipiodol uptake in MSCT. In TACP the intercostal arteries involved could be visualized and in 30% of interventions the catheter had to be repositioned for the following intervention. C-arm CT provides additional information on the vascular characteristics and perfusion of pulmonary lesions resulting in a change of interventional strategy in a relevant number of patients. (orig.) [German] Ziel der Arbeit war die Evaluation der Wertigkeit der C-Arm CT fuer die online gesteuerte regionale transarterielle Chemoperfusion (TACP) und die transpulmonale Chemoembolisation (TPCE) primaerer und sekundaerer thorakaler Neoplasmen Von September 2008 bis Maerz 2009 wurden 31 Patienten (11 Frauen/20 Maenner, Durchschnittsalter 61,7 Jahre) mit 53 unterschiedlichen thorakalen Neoplasmen (primaere oder sekundaere Lungenkarzinome [n=37], Pleuramesotheliome [n=16]) mittels TACP oder TPCE unter Einsatz der Flachdetektortechnologie (FD-CT) behandelt. Alle Behandlungen erfolgten an einem C

  1. Value of breast MRI as supplement to mammography and sonography for high risk breast cancer patients; Wertigkeit der Mamma-MRT als Ergaenzung zu Mammographie und Sonographie bei Patientinnen mit erhoehtem Mammakarzinomrisiko

    Energy Technology Data Exchange (ETDEWEB)

    Schlossbauer, T.; Hellerhoff, K.; Reiser, M. [Klinikum Grosshadern der Ludwig-Maximilians-Universitaet Muenchen, Institut fuer Klinische Radiologie, Muenchen (Germany)

    2008-04-15

    The aim of this study is to give an overview on early detection of breast cancer in patients with an increased risk of breast cancer. Sensitivities and diagnostic accuracies of breast MRI, mammography and ultrasound were compared. A systematic literature search of the past 3 years was performed. Studies which compared breast imaging modalities and used image-guided biopsy results as standard of reference were included. Patients included had to have had an increased lifetime risk for breast cancer (>15%). Regarding sensitivity and diagnostic accuracy, breast MRI performed best in comparison to the other modalities within this collective of patients. Sensitivities ranged from 71-100%, 0-78%, and 13-65%, for MRI, mammography, and ultrasound, respectively Breast MRI is a well established tool for screening in patients at high risk for developing breast cancer and is a valuable supplement to mammography and ultrasound within this selected cohort of patients. (orig.) [German] Ziele der Arbeit sind die inhaltliche Einfuehrung in das Thema Frueherkennung des Mammakarzinoms bei Patientinnen mit erhoehtem Risiko und eine systematische Analyse der Wertigkeit von MRT und anderen bildgebenden Verfahren in diesem Zusammenhang. Es wurde eine systematische Literaturrecherche ueber die letzten 3 Jahre durchgefuehrt. Dabei wurden Vergleichsstudien der verschiedenen bildgebenden Verfahren in der Mammadiagnostik beruecksichtigt, bei denen die bildgesteuerte Biopsie als Goldstandard angegeben wurde. Von allen bildgebenden Verfahren zeigt die Mamma-MRT bei Patientinnen mit familiaerem Risiko die hoechste Sensitivitaet und diagnostische Genauigkeit bei der Detektion des Mammakarzinoms. Fuer MRT, Mammographie und Sonographie werden Sensitivitaeten zwischen 71 und 100%, 0 und 78% sowie 13 und 65% angegeben. Die Mamma-MRT ist ein etabliertes Verfahren zum Screening von Risikopatientinnen. Uebereinstimmend wird der diagnostische Nutzen der Mamma-MRT als ergaenzendes Verfahren zu Mammographie

  2. Influence of platform screen doors on energy consumption of the environment control system of a mass rapid transit system: case study of the Taipei MRT system

    International Nuclear Information System (INIS)

    Hu, S.-C.; Lee, J.-H.

    2004-01-01

    This investigation studies how platform screen doors (PSD) affect the energy consumption of the environmental control system of a mass rapid transit (MRT) system in Taipei. The environmental parameter simulation was conducted using the subway environmental simulation (SES) program, while the associated air conditioning (A/C) cooling load was predicted with the carrier E20-II program. Results show that PSD can significantly decrease average and peak cooling load, thus reducing the capacity/size of cooling equipment and allowing the chiller cooling load to be abridged. However, electricity consumption by ventilation equipment increases notably when PSD are used, particularly the electricity consumption by the under platform exhaust (UPE) fan, and thus, ultimately, little difference exists in the overall energy consumption with and without UPE

  3. Influence of platform screen doors on energy consumption of the environment control system of a mass rapid transit system: case study of the Taipei MRT system

    Energy Technology Data Exchange (ETDEWEB)

    Hu, S.-C. E-mail: f10870@ntut.edu.tw; Lee, J.-H

    2004-03-01

    This investigation studies how platform screen doors (PSD) affect the energy consumption of the environmental control system of a mass rapid transit (MRT) system in Taipei. The environmental parameter simulation was conducted using the subway environmental simulation (SES) program, while the associated air conditioning (A/C) cooling load was predicted with the carrier E20-II program. Results show that PSD can significantly decrease average and peak cooling load, thus reducing the capacity/size of cooling equipment and allowing the chiller cooling load to be abridged. However, electricity consumption by ventilation equipment increases notably when PSD are used, particularly the electricity consumption by the under platform exhaust (UPE) fan, and thus, ultimately, little difference exists in the overall energy consumption with and without UPE.

  4. Diagnostic imaging of Klippel-Feil syndrome: conventional radiography, CT and MR imaging. Case report; Bildgebende Diagnostik des Klippel-Feil-Syndroms: Konventionelle Roentgenaufnahmen, CT und MRT. Fallbericht

    Energy Technology Data Exchange (ETDEWEB)

    Jochens, R. [Strahlenklinik und Poliklinik, Universitaetsklinikum Rudolf Virchow, Freie Univ. Berlin (Germany); Schubeus, P. [Strahlenklinik und Poliklinik, Universitaetsklinikum Rudolf Virchow, Freie Univ. Berlin (Germany); Steinkamp, H.J. [Strahlenklinik und Poliklinik, Universitaetsklinikum Rudolf Virchow, Freie Univ. Berlin (Germany); Menzhausen, L. [Abt. fuer Psychiatrie, Urban Krankenhaus, Berlin (Germany); Felix, R. [Strahlenklinik und Poliklinik, Universitaetsklinikum Rudolf Virchow, Freie Univ. Berlin (Germany)

    1993-12-31

    In two patients with Klippel-Feil syndrome, type II radiographic findings of the malformation are shown in the cervical spine and the craniocervical junction. Conventional X-rays of the cervical spine in the AP and lateral view and conventional tomography as well as CT of the cervical spine were obtained in both patients. One of the two patients additionally underwent MR imaging. Findings of the different imaging modalities are compared with each other. (orig.) [Deutsch] Anhand von zwei Patienten mit Klippel-Feil-Syndrom Typ II werden typische radiologische Befunde des Missbildungssyndroms im Bereich der Halswirbelsaeule und des kraniozervikalen Ueberganges dargestellt. Neben den konventionellen HWS-Roentgenaufnahmen und den konventionellen Schichtaufnahmen, wurden bei beiden Patienten ein CT der HWS und bei einem Patienten zusaetzlich ein MRT durchgefuehrt. Die Ergebnisse und Befunde der verschiedenen Untersuchungsverfahren werden einander gegenuebergestellt. (orig.)

  5. Functional CT imaging: load-dependent visualization of the subchondral mineralization by means of CT osteoabsorptionmetry (CT-OAM); Funktionelle Computertomographie: Beanspruchungsabhaengige Darstellung der subchondralen Mineralisierung mittels CT gestuetzter Osteoabsorptiometrie (CTOAM)

    Energy Technology Data Exchange (ETDEWEB)

    Linsenmaier, U.; Schlichtenhorst, K.; Pfeifer, K.J.; Reiser, M. [Inst. fuer Klinische Radiologie, Innenstadt, Ludwig-Maximilians-Univ. Muenchen (Germany); Kersting, S.; Putz, R.; Mueller-Gerbl, M. [Anatomische Anstalt, Ludwig-Maximilians-Univ. Muenchen (Germany)

    2003-05-01

    Purpose: Functional computed tomography for visualization and quantification of subchondral bone mineralization using CT osteoabsorptiometry (CT-OAM). Materials and Methods: Tarsometatarsal (TMT) and metatarsophalangeal (MTP) joints of 46 human hallux valgus (HV) specimens were examined (sagittal 1/1/1 mm) on a single slice CT scanner SCT (Somatom Plus 4, Siemens AG). Subchondral bone pixels were segmented and assigned to 10 density value groups (triangle 100 HU, range 200 - 1200 HU) the pixels using volume rendering technique (VRT). The data analysis considered the severity of HV as determined by the radiographically measured HV-angle (a.p. projection). Results: CT-OAM could generate reproducible densitograms of the distribution pattern of the subchondral bone density for all four joint surfaces (TMT and MTP joints). The bone density localization enables the assignment to different groups, showing a characteristic HV-angle-dependent distribution of the maximum bone mineralization of the load-dependent densitogram (p < 0.001). Conclusion: CT-OAM is a functional CT technique for visualizing and quantifying the distribution of the subchondral bone density, enabling a noninvasive load-dependent assessment of the joint surfaces. Load-dependent densitograms of hallux valgus specimens show a characteristic correlation with an increase of the HV-angle. (orig.) [German] Ziel: Darstellung und Quantifizierung der subchondralen Mineralisierung in Abhaengigkeit von unterschiedlichen Beanspruchungssituationen mittels funktioneller Computertomographie als CT-Osteoabsorptiometrie (CT-OAM). Methode: An 46 humanen Praeparaten mit Hallux valgus (HV) wurden exemplarisch die TMT I (Tarsometatarsal)- und MTP I (Metatarsophalangeal)-Gelenke des ersten Strahles (sagittal 1/1/1 mm) an einem Singleslice Spiral-CT (SCT, Somatom Plus 4, Siemens AG) untersucht. Der subchondrale Knochen wurde segmentiert, den Pixel wurde mittels Volume Rendering Technik (VRT) 10 Graustufenbereiche (D100 HU

  6. The effect of highly potent, static magnetic fields used in magnetic resonance tomography (MRT) on the red-green vision of man

    International Nuclear Information System (INIS)

    Hancken, G.C.W.

    1989-01-01

    The ability of red-green differentiation before and after MRT exposure to a static magnetic field of a potency of 0.5 Tesla was examined in a total of 32 volunteers and contrastet to that of 128 further test persons before and after CT, linear accelerator irradiation and ultrasonography as well as to findings revealed in a control group. The greatest number of significant colour misjudgements was seen in the MRT group, where 57% of patients had deteriorated colour vision. Volunteers treated at CT units or linear accelerators also showed deviations from the normal red-green vision in 48.5% and 38.7% of cases. In the ultrasound and control groups, no more than 25% and 13.3% of the values measured using the anomaloscope suggested changes from normal. Exposure to a 0.5 Tesla magnetic field led to slight shifts in colour vision for a great number of patients. These appear to be brought about by light-sensitive photoreceptors in the retinal cone cells that respond to magnetic field influences. Theories about the underlying mechanisms are explained and discussed. The results obtained in the ultrasound and control groups have, however, also made evident that some individuals are prone to changes in colour vision without having been exposed to any measurable physical influences. These appear to be chiefly attributable to factors like stress. It would be most interesting to know to which extent study results such as these are distorted by personal perceptions and mental factors. (orig./MG) [de

  7. MR of the muskuloskeletal system: A review; MR-Tomographie (MRT) des Skeletts, der peripheren Weichteile und der Gelenke - aktuelle Uebersicht

    Energy Technology Data Exchange (ETDEWEB)

    Bohndorf, K. [Zentralklinikum Augsburg (Germany). Klinik fuer Diagnostische und Neuroradiologie; Kretschmer, K.H. [Zentralklinikum Augsburg (Germany). Klinik fuer Diagnostische und Neuroradiologie

    1996-05-01

    The skeleton, the peripheral soft tissues, and the joints have become important indications to use MRI routinely. About 25-35% of daily examinations focus on these anatomic sites. Superior contrast resolution, the option of different imaging planes, and the unsurpassed visualization of bone marrow, fibrous and hyaline cartilage, ligaments, and tendons are the reasons for the overwhelming success of this imaging method. MRI often provides the direct way to diagnosis. More and more the so-called `step by step` approach to diagnosis by imaging methods is being abandoned in favor of the primary use of MRI. The present survey summarizes the main indications for MRI in the field of the musculoskeletal system, in adults as well as in children. Special topics like tumors, inflammation, ischemia, and trauma are discussed. Some anatomic sites like the carpal joint, the shoulder, and the knee are presented in more detail. (orig.) [Deutsch] Eine Vielzahl von Fragestellungen zu wesentlichen Indikationen der MR-Tomographie am Skelett, den peripheren Weichteilen und den Gelenken haben sich in der taeglichen Praxis entwickelt. Durchschnittlich 25-35% der taeglichen Untersuchungen betreffen diesen Themenkreis. Ueberlegene Kontrastaufloesung, die Darstellung in beliebig waehlbaren Ebenen und die unuebertroffene Visualisierung von Strukturen wie Knochenmark, fibroesem und hyalinem Knorpel, Ligamenten und Sehnen, sind die Ursache der raschen Verbreitung der Methode. Die MRT stellt haeufig den direkten Weg zur Diagnose dar und ersetzt zunehmend die sog. `Stufendiagnostik` und damit Methoden wie die Computertomographie, Arteriographie oder auch Skelettszintigraphie. In der vorliegenden Uebersicht werden wesentliche, heute als gesichert anzusehenden Anwendungsgebiete der MRT bei Kindern und Erwachsenen zusammengefasst. Die Arbeit gibt einen Ueberblick ueber spezielle Fragestellungen bei Tumoren, Entzuendungen, Ischaemie und traumatischen Fragestellungen. Eine Reihe von anatomischen

  8. Sensitivity of MRI in detecting alveolar infiltrates. Experimental studies; Sensitivitaet der MRT fuer alveolaere Infiltrate. Experimentelle Untersuchungen

    Energy Technology Data Exchange (ETDEWEB)

    Biederer, J.; Busse, I.; Grimm, J.; Reuter, M.; Heller, M. [Kiel Univ. (Germany). Klinikum fuer Diagnostische Radiologie; Muhle, C. [Kiel Univ. (Germany). Klinik fuer Nuklearmedizin; Freitag, S. [Kiel Univ. (Germany). Inst. fuer Medizinische Informatik und Statistik

    2002-08-01

    detect pneumonia in patients. (orig.) [German] Zielsetzung: Eine experimentelle Studie zur Untersuchung des Signalverhaltens artifizieller alveolaerer Infiltrate mit T{sub 1}- und T{sub 2}-gewichteten MR-Sequenzen. Material und Methoden: 10 Lungen-Explantate von Schweinen wurden tracheal intubiert, in der kuenstlichen Thoraxhoehle eines Phantoms durch Unterdruck entfaltet und an einem klinischen Magnetresonanztomographen bei 1,5 T untersucht. Mit gezielter Instillation von 100-200 ml Gelatineloesung wurden alveolaere Infiltrate erzeugt und mit Gradientenecho- (2D-, 3D-GRE) und schnellen Spinechosequenzen (T{sub 2}-TSE, T{sub 2}-HASTE) dargestellt. Die Signalintensitaet des Lungenparenchyms nativ und mit Infiltrat wurde an repraesentativen Querschnitten erfasst. Zum Vergleich erfolgten Kontrollen mit Spiral-CT. Ergebnisse: Die instillierte Fluessigkeit simulierte alveolaere Infiltrate mit typischem Milchglasmuster im CT, wie es an Patienten mit Pneumonie oder ARDS beobachtet wird. Vor dem Versuch zeigten nur T{sub 2}-HASTE und T{sub 2}-TSE ein Lungenparenchymsignal (Signal/Rausch-Verhaeltnis von 3,62 bzw. 1,39). Nach Instillation von Fluessigkeit fand sich in diesen Sequenzen ein Signalanstieg von ca. 30% bei 100 ml (p<0,01) bzw. 60% bei 200 ml (p<0,01). Bei 2D-GRE betrug die Signalintensitaetszunahme 0,74% (p=0,32) nach 100 ml und 5,6% (p<0,01) nach 200 ml (fuer 3D-GRE 2,2% [p=0,02] bzw. 4,4% [p<0,01]). Die CT-Kontrollen zeigten fuer 100 ml eine Dichtezunahme um durchschnittlich 17 H.E. (p=0,02) und fuer 200 ml um 75 H.E. (p<0,01). Schlussfolgerungen: Mit T{sub 2}-gewichteten Sequenzen ist die MRT zur Darstellung artifizieller alveolaerer Infiltrate geeignet. (orig.)

  9. The role of high-resolution computed tomography (HRCT) and magnetic resonance imaging (MRI) in the diagnosis of preoperative and postoperative complications caused by acquired cholesteatomas; CT und MRT des erworbenen Cholesteatoms: Prae- und postoperative Bildgebung

    Energy Technology Data Exchange (ETDEWEB)

    Krestan, C.; Czerny, C. [Abteilung fuer Osteologie, Univ.-Klinik fuer Radiodiagnostik, Wien (Austria); Gstoettner, W. [Univ.-Klinik fuer Hals-Nasen-Ohren-Heilkunde, Frankfurt (Germany); Franz, P. [Univ.-Klinik fuer Hals-Nasen-Ohren-Heilkunde, Wien (Austria)

    2003-03-01

    The role of high-resolution computed tomography (HRCT) and magnetic resonance imaging (MRI) in the diagnosis of preoperative and postoperative complications caused by acquired cholesteatomas will be described in this paper. The pre- and postoperative imaging of the temporal bone was performed with HRCT and MRI. HRCT and MRI were performed in the axial and coronal plane. MRI was done with T2 weighted and T1 weighted sequences both before and after the intravenous application of contrast material. All imaging findings were confirmed clinically or surgically. The preoperative cholesteatoma-caused complications depicted by HRCT included bony erosions of the ossicles, scutum, facial canal in the middle ear, tympanic walls including the tegmen tympani, and of the labyrinth. The preoperative cholesteatoma-caused complications depicted by MRI included signs indicative for labyrinthitis, and brain abscess. Postoperative HRCT depicted bony erosions caused by recurrent cholesteatoma, bony defects of the facial nerve and of the labyrinth, and a defect of the tegmen tympani with a soft tissue mass in the middle ear. Postoperative MRI delineated neuritis of the facial nerve, labyrinthitis, and a meningo-encephalocele protruding into the middle ear. HRCT and MRI are excellent imaging tools to depict either bony or soft tissue complications or both if caused by acquired cholesteatomas. According to our findings and to the literature HRCT and MRI are complementary imaging methods to depict pre- or postoperative complications of acquired cholesteatomas if these are suspected by clinical examination. (orig.) [German] In dieser Arbeit wird die Rolle der hochaufloesenden Computertomographie (HRCT) und der Magnetresonanztomographie (MRT) zur Abklaerung prae- und postoperativ bedingter Komplikationen erworbener Cholesteatome beschrieben. Die Bildgebung wurde sowohl mit der HRCT als auch mit der MRT durchgefuehrt. Die HRCT und die MRT wurden in axialer und koronaler Ebene (auch

  10. The value of magnetic resonance imaging (MRI) in the treatment planning of vertebral metastasis considering economic aspects. A cost benefit-analysis; Die Wertigkeit der Magnetresonanztomographie (MRT) unter oekonomischen Aspekten bei der Bestrahlungsplanung von Wirbelkoerpermetastasen. Eine Kosten-Nutzen-Analyse

    Energy Technology Data Exchange (ETDEWEB)

    Prott, F.J.; Schlehuber, E.; Scharding, B.J.; Rinast, E. [Strahlentherapie Wiesbaden, St.-Josefs-Hospital (Germany); Micke, O. [Klinik und Poliklinik fuer Strahlentherapie - Radioonkologie, Universitaetsklinikum Muenster (Germany)

    2002-05-01

    Is magnetic resonance imaging (MRI) based target volume definition for treatment planning of vertebral metastasis effective under economic considerations.From 1994 to 1999, a total of 137 patients with bone metastases affecting the vertebral column underwent MRI of the cercival, thoracic, or lumbar spine for the treatment planning of palliative radiation therapy. The following radiation treatment consisted in a irradiation of the affected vertebral region up to a total dose of 30-40 Gy.The cost calculation for radiotherapy and magnetic resonance tomography was done using the common tariff model (EBM) of the German Health Insurances.In 73% of patients (101 patients), magnetic resonance imaging resulted in marked corrections of the irradiation fields which would have resulted in the necessity of treatment for recurrence in the case of treatment planning without MRI.Consequently, the higher cost of MRI of 345.00 DEM (176,40 EUR) lead to a saving of 497.00 DEM (254,11 EUR) compared to a recurrence treatment of 10 fractions and of 1,428.00 DEM (730,12 EUR) compared to 20 fractions. The transport expenses for the second treatment could be saved as well.Even under economic considerations MRI is effective. (orig.) [German] Ist eine MRT-gestuetzte Zielvolumendefinition bei der Strahlentherapie von Knochenmetastasen ein sinnvolles Vorgehen unter oekonomischen Gesichtspunkten?1994-1999 wurde bei 137 Patienten mit einem ossaer metastasierenden Tumor und Befall der Wirbelsaeule eine Magnetresonanztomographie (MRT) zur Planung einer palliativen Radiatio durchgefuehrt. Die nachfolgende Strahlentherapie bestand aus einer Radiatio des betroffenen Wirbelkoerperabschnitts bis zu einer Gesamtherddosis von 30-40 Gy. Fuer die Berechnung der Kosten wurde der einheitliche Bewertungsmassstab der Deutschen Krankenkassen zugrunde gelegt.Aufgrund der MRT-Untersuchungen wurde bei 73% der Patienten eine Veraenderung des Bestrahlungsfeldes vorgenommen, die im Falle einer nicht MRT

  11. First clinical experience with extended planning and navigation in an interventional MRI unit; Erste klinische Erfahrungen mit einer erweiterten Eingriffsplanung und Navigation am interventionellen MRT

    Energy Technology Data Exchange (ETDEWEB)

    Moche, M.; Schneider, J.P.; Schulz, T.; Voerkel, C.; Kahn, T.; Busse, H. [Klinik und Poliklinik fuer Diagnostische Radiologie, Universitaetsklinikum Leipzig (Germany); Schmitgen, A.; Bublat, M. [Fraunhofer-Inst. fuer Angewandte Informationstechnik, St. Augustin (Germany); Trantakis, C. [Klinik und Poliklinik fuer Neurochirurgie, Universitaetsklinikum Leipzig (Germany); Bennek, J. [Klinik und Poliklinik fuer Kinderchirurgie, Univ. Leipzig (Germany)

    2004-07-01

    Purpose: To present an advanced concept for patient-based navigation and to report on our first clinical experience with interventions in the cranium, of soft-tissue structures (breast, liver) and in the musculoskeletal system. Materials and Methods: A PC-based navigation system was integrated into an existing interventional MRI environment. Intraoperatively acquired 3D data were used for interventional planning. The information content of these reference data was increased by integration of additional image modalities (e. g., fMRI, CT) and by color display of areas with early contrast media enhancement. Within 18 months, the system was used in 123 patients undergoing interventions in different anatomic regions (brain: 64, paranasal sinus: 9, breast: 20, liver: 17, bone: 9, muscle: 4). The mean duration of 64 brain interventions was compared that of 36 procedures using the scanner's standard navigation. Results: In contrast with the continuous scanning mode of the MR system (0.25 fps), the higher quality as well as the real time display (4 fps) of the MR images reconstructed from the 3D reference data allowed adequate hand-eye coordination. With our system, patient movement and tissue shifts could be immediately detected intraoperatively, and, in contrast to the standard procedure, navigation safely resumed after updating the reference data. The navigation system was characterized by good stability, efficient system integration and easy usability. Despite additional working steps still to be optimized, the duration of the image-guided brain tumor resections was not significantly longer. (orig.) [German] Ziel: Vorstellung eines erweiterten Konzepts zur patientenbasierten Navigation sowie erste klinische Bewertung der durchgefuehrten Massnahmen im Kopf, Weichteil- und muskuloskeletalen Bereich. Material und Methode: Ein PC-basiertes Navigationssystem wurde in eine vorhandene interventionelle MRT-Umgebung integriert. Intraoperativ akquirierte 3-D

  12. Utility of coronal oblique slices in cervical spine MRI. Improved detection of the neuroforamina; Nutzen der halbkoronaren Schichtung im MRT der Halswirbelsaeule. Verbesserte Erkennbarkeit von Neuroforamina

    Energy Technology Data Exchange (ETDEWEB)

    Freund, W.; Hoepner, G. [Universitaetskliniken Ulm, Klinik fuer Diagnostische und Interventionelle Radiologie, Ulm (Germany); Klessinger, S. [Nova Clinic Biberach, Neurochirurgie, Biberach (Germany); Universitaetskliniken Ulm, Neurochirurgie, Ulm (Germany); Mueller, M. [Universitaetskliniken Ulm, Klinik fuer Diagnostische und Interventionelle Radiologie, Ulm (Germany); Universitaetskliniken Aachen, Diagnostische und Interventionelle Neuroradiologie, Aachen (Germany); Halatsch, M.E. [Universitaetskliniken Ulm, Neurochirurgie, Ulm (Germany); Weber, F. [Bundeswehrkrankenhaus Ulm, Neurologie, Ulm (Germany); Schmitz, B. [Universitaetskliniken Ulm, Neuroradiologie, Ulm (Germany)

    2015-11-15

    Angulated projections are standard in conventional radiography of the cervical spine, but rarely used in magnetic resonance imaging (MRI). As neuroforaminal pathology plays an important role in the etiology of radicular syndromes and may influence an operative approach, the utility of coronal oblique slices in MRI is explored. In a retrospective setting, 25 consecutive patients with neurologically diagnosed cervical monoradiculopathy were identified. T2-weighted sagittal, coronal oblique, and transversal slice orientations were anonymized. Two radiologists and two neurosurgeons independently assessed the cases. Criteria were site, cause, and grading of the neuroforaminal stenosis and the level of confidence on a 100-point visual analog scale (VAS). We computed interrater agreement, sensitivity, and t tests. Using only one slice orientation, the sensitivity in detecting the relevant neuroforamen was 0.40 for transversal, 0.68 for sagittal, and 0.64 for coronal oblique scans. A combination of the different angulations increased sensitivity and in 4 cases only the coronal oblique scans proved diagnostic. The readers felt significantly more confident in attributing the cause of the pathology on coronal oblique planes (a mean of 72 VAS points, p = 0.0003 vs 58 (sagittal) vs 64 (transversal)). Interrater agreement was significantly better for experienced (kappa 0. 48) than for inexperienced readers (0.32, p = 0.02). Adding coronal oblique planes in cervical spine MRI increases sensitivity and confidence in attributing the cause of neuroforaminal pathology. They are regarded as useful by all the readers. (orig.) [German] Im Gegensatz zur Magnetresonanztomographie (MRT) sind in der konventionellen Roentgendiagnostik der Halswirbelsaeule (HWS) Schraegaufnahmen Standard. Da neuroforaminale Pathologien wichtige Ursachen von radikulaeren Syndromen sind und die Operationstechnik moeglicherweise beeinflussen, wird der Nutzen halbkoronarer Schichten in der MRT untersucht. In

  13. Quantitatively evaluated dynamic MRT in rheumatoid arthritis of the knee joint. Follow-up after intraarticular steroid therapy. Quantitativ evaluierte dynamische Magnetresonanztomographie bei chronischer Polyarthritis des Kniegelenkes. Therapiekontrolle nach intraartikulaerer Kortisonapplikation

    Energy Technology Data Exchange (ETDEWEB)

    Koenig, H.; Bolze, X.; Wolf, K.J. (Klinikum Steglitz, FU Berlin, Radiologische Klinik und Poliklinik, Abt. fuer Radiologische Diagnostik und Nuklearmedizin (Germany)); Sieper, J. (Klinikum Steglitz, FU Berlin, Medizinische Klinik und Poliklinik, Abt. fuer Allgemeine Innere Medizin und Nephrologie (Germany))

    1992-08-01

    32 patients with chronic polyarthritis were examined by MRT. Following intra-articular application of 25 mg prednisolon, 18 patients were reexamined after two of three weeks and 7 out of 18 patients were re-examined after 8 to 16 weeks, both by MRT and clinically. After an initial double echo sequence, we carried out a dynamic series of FLASH measurements (TR 30, TE 10 ms, 70deg) following an intravenous bolus of 0.1 mmol gadolinium-DTPA. Single intensity-time curves were treated quantitatively in relation to the pannus, muscles and effusions. Two or three weeks after treatment the curve parameters showed a reduction in pannus vascularisation which remained constant for the 8 to 16 weeks of further observation. Contrast diffusion in the pannus is initially reduced but approaches the early measurements at the time of the second examination. (orig.).

  14. Long term results of mantle irradiation(MRT) alone in 261 patients with clinical stage I-II supradiaphragmatic Hodgkin's disease

    International Nuclear Information System (INIS)

    Wirth, A.; Byram, D.; Chao, M.; Corry, J.; Davis, S.; Kiffer, J.; Laidlaw, C.; Quong, G.; Ryan, G.; Liew, K.

    1997-01-01

    Purpose: We report our results using MRT for clinical stage I-II HD and assess the value of published prognostic criteria in our study population. Pts and Methods: Between 1969 and 1994, 261 pts were treated with MRT alone for clinical stage I-II supradiaphragmatic HD. Pt characteristics: median age-30; M-54%/F-46%; stage IA-52%, IB-2%, IIA-37%, IIB-8%; histology LP-21%, NS-51%, MC-23%, other 5%; median ESR 18. CT abdomen and LAG were performed in 61% and 60% respectively. No pt had prior staging laparotomy. No pt received infradiaphragmatic RT. Central axis dose was 32 Gy-36 Gy. Univariate analysis was performed for prognostic factors for progression-free (PFS) and overall survival(OS). Outcome was assessed in favourable subsets as defined by: EORTC (v. favourable: CSIA, LP or NS histology, age < 40, female, no bulk, ESR < 50; favourable: CSI-II, age < 50, < 4 sites, no bulky mediastinal mass, ESR < 50 with no B symptoms or ESR < 30 with B symptoms); Princess Margaret Hospital (PMH) (IA-IIA, LP or NS histology, ESR < 40, age < 50, no large mediastinal mass, no E lesion). Results: 261 pts completed RT, with 5% requiring treatment interruption for toxicity. Significant factors (P<0.05) for PFS were stage, performance status, histology, B symptoms, number of sites, ESR and bulk. Significant factors (P<0.05) for OS were age, performance status, histology and B symptoms. (The results of a multivariate analysis will be presented.) Results in our study population using published prognostic criteria (in %): Thirty-six percent progressed following RT: 8% in-field; 24% out of field only (including 10% in the paraaortic/splenic region alone); 4% marginal; Fifty-seven percent of relapsed pts remain progression free after subsequent salvage treatment. Two cases of acute leukaemia, 8 cases of non-Hodgkin's lymphoma and 14 (non-skin) carcinomas occurred, of which 11 were in-field. Seventy pts have died. The cause was: HD 41%; other malignancy 20%; cardiovascular 17%; other 15

  15. Gaucher disease: MR evaluation of bone marrow features during treatment with enzyme replacement; Morbus Gaucher: Analyse der Knochenmarkveraenderungen in der MRT waehrend Enzymersatztherapie

    Energy Technology Data Exchange (ETDEWEB)

    Poll, L.W.; Koch, J.A.; Boerner, D.; Cohnen, M.; Jung, G.; Scherer, A.; Moedder, U. [Duesseldorf Univ. (DF). Inst. fuer Diagnostische Radiologie; Dahl, S. vom; Haeussinger, D. [Duesseldorf Univ. (Germany). Klinik fuer Gastroenterologie, Hepatologie und Infektiologie; Willers, R. [Rechenzentrum, Heinrich-Heine-Univ. Duesseldorf (Germany); Niederau, C. [Innere Abt., St. Josef-Hospital Oberhausen, Akademisches Lehrkrankenhaus der Univ. Essen (Germany)

    2001-10-01

    Purpose: Enzyme replacement therapy (ERT) arrests and reverses the hematological and visceral symptoms of adult Gaucher disease, the most frequent lysosomal storage disorder. There are only a few studies available evaluating bone disease during ERT. The aim of this study was to investigate the features of bone marrow (bm) by magnetic resonance imaging (MRI) in these patients during ERT. Materials and Methods: MRI was performed prospectively in thirty adult type I Gaucher patients before and during ERT with a mean follow-up of 3 years. Spin-echo sequences (T{sub 1}/T{sub 2}) of the lower extremities were obtained and the reconversion (response) or lack of reconversion (non-response) to fatty marrow during treatment was analyzed. The morphological features of bm involvement, a homogeneous or non-homogeneous distribution of bm changes and focal bone lesions surrounded by a rim of reduced signal intensity (SI), were analyzed. Results: Infiltration of bm by Gaucher cells is characterized by a reduction of Sl on both T{sub 1}- and T{sub 2}-weighted sequences. Bone marrow responses were seen in 19 patients (63%) during treatment. Focal bone lesions, surrounded by a rim of reduced Sl, did not respond to ERT and correlated with a non-homogenous distribution of bone involvement and splenectomy. (orig.) [German] Ziel: Unter Enzymersatztherapie (enzyme replacement therapy = ERT) zeigen Patienten mit adulter Form des Morbus Gaucher, der haeufigsten lysosomalen Speicherkrankheit, eine deutliche Besserung der haematologischen und visceralen Symptome. Bislang liegen nur wenige Untersuchungen zur Analyse der Knochenveraenderungen waehrend der ERT vor. Ziel war es, die Knochenmarkveraenderungen bei Gaucher-Patienten waehrend der Enzymersatztherapie mit Alglucerase/Imiglucerase in der Magnetresonanztomographie (MRT) zu evaluieren. Material und Methoden: In einer prospektiven Untersuchung wurden 30 adulte Patienten mit gesichertem Morbus Gaucher vor und waehrend der ERT in der MRT

  16. MRI, CT, and sonography in the preoperative evaluation of primary tumor extension in malignant pleural mesothelioma; MRT, CT und Sonographie in der praeoperativen Beurteilung der Primaertumorausdehnung beim malignen Pleuramesotheliom

    Energy Technology Data Exchange (ETDEWEB)

    Layer, G.; Steudel, A.; Schild, H.H. [Radiologische Universitaetsklinik Bonn (Germany); Schmitteckert, H.; Tuengerthal, S.; Schirren, J. [Thoraxklinik Heidelberg-Rohrbach (Germany); Kaick, G. van [Deutsches Krebsforschungszentrum Heidelberg (Germany). Schwerpunkt fuer Onkologische Diagnostik und Therapie

    1999-04-01

    Purpose: Evaluation of the diagnostic value of the imaging modalities computed tomography (CT), magnetic resonance imaging (MRI), and thoracic sonography in the preoperative staging of malignant pleural mesothelioma. Results: The accuracy rates for CT were 85%, 98%, 83%, 73%, 71%, and 83%. MRI had an accuracy of 71%, 92%, 71%, 83%, 71%, and 96%, the thoracic ultrasound examinations of 76%, 63%, 51%, 60%, 71% and 89%. Conclusions: According to these results CT remains the method of choice in the preoperative assessment of T-stage of malignant pleural mesothelioma. MRI is of nearly the same value, but is not a must. Sonography may be supplementary method for operation planning. (orig./AJ) [Deutsch] Ziel: Evaluation der diagnostischen Wertigkeit der Schnittbildverfahren MRT, CT und Sonographie in der praeoperativen Diagnostik des Pleuramesothelioms. Ergebisse: Die Treffsicherheiten betrugen fuer die genannten anatomischen Regionen im CT 85%, 98%, 83%, 73%, 71%, und 83%, im MRT 71%, 92%, 71%, 83%, 71% bzw. 96%, waehrend sich fuer die thorakale Ultraschalluntersuchung Treffsicherheiten von 76%, 63%, 51%, 60%, 71% und 89% errechneten. Schlussfolgerungen: Die CT bleibt damit das Verfahren erster Wahl in der praeoperativen Diagnostik des malignen Pleuramesothelioms. Eine unbedingte Forderung nach praeoperativer Durchfuehrung einer MRT-Untersuchung ergibt sich nach der vorliegenden Studie nicht. Die Sonographie des Thorax und oberen Abdomens liefert einen wichtigen ergaenzenden Beitrag bei der Planung der Operation des malignen Pleuramesothelioms. (orig./AJ)

  17. Relapsing mastitis 17 years after the augmentation mammoplasty with PAAG followed by follicular Non-Hodgkin's lymphoma - MRT, US and PET /CT findings

    International Nuclear Information System (INIS)

    Spirdonov, J.; Sedloev, T.

    2017-01-01

    A case of a 51-year-old woman with mastitis in her right breast 17 years after Augmentation Mammoplasty with PAAG produced in Ukraine is presented, the MRI and mammary US findings are discussed. Solid areas in the background of the non-structural gel are established, hardly to be distinguished from primary mammary lesions. At a control US examination 6 months after the surgical intervention, an increase in new l.n. in the right axilla is established. The biopsy performed discovered the histological features for follicular non-Hodgkin's lymphoma grade 2, CD 20 (+) sex. The links of the lymphoma as a systemic manifestation of the local cytotoxic effect in the C-myc gene expression of the medical polyacrylamide hydrogel is questionable. In all women after Augmentation Mammoplasty with PAAG 6-month follow-ups with US are recommended, completed with MRI if needed and, annual blood tests as well. For equivocal clinical examinations and imaging studies, proceed to a FNB or Cor biopsy under US control. Key words: Mastitis. Augmentation MAMMOPLASTY. PAAG, US. MRT. PET/CT Follicular Non-Hodgkin's Lymphoma [bg

  18. Calculation of Friction Coefficient and Analysis of Fluid Flow in a Stepped Micro-Channel for Wide Range of Knudsen Number Using Lattice Boltzmann (MRT Method

    Directory of Open Access Journals (Sweden)

    Y. Bakhshan

    2015-01-01

    Full Text Available Micro scale gas flows has attracted significant research interest in the last two decades. In this research, the fluid flow of gases in the stepped micro-channel at a wide range of Knudsen number has been analyzed with using the Lattice Boltzmann (MRT method. In the model, a modified second-order slip boundary condition and a Bosanquet-type effective viscosity are used to consider the velocity slip at the boundaries and to cover the slip and transition regimes of flow and to gain an accurate simulation of rarefied gases. It includes the slip and transition regimes of flow. The flow specifications such as pressure loss, velocity profile, streamline and friction coefficient at different conditions have been presented. The results show good agreement with available experimental data. The calculation shows that the friction coefficient decreases with increasing the Knudsen number and stepping the micro-channel has an inverse effect on the friction coefficient. Furthermore, a new correlation is suggested for calculation of the friction coefficient in the stepped micro-channel as below: C_f Re  = 3.113+2.915/(1 +2 Kn+ 0.641 exp⁡(3.203/(1 + 2 Kn

  19. Fetal lung development on MRI. Normal course and impairment due to premature rupture of membranes; Fetale Lungenentwicklung in der MRT. Normaler Verlauf und Beeintraechtigung durch vorzeitigen Blasensprung

    Energy Technology Data Exchange (ETDEWEB)

    Kasprian, G. [Medizinische Universitaet Wien (Austria). Klinik fuer Radiodiagnostik; Zentrum fuer Anatomie und Zellbiologie der Medizinischen Universitaet Wien (Austria). Arbeitsgruppe Integrative Morphologie; Brugger, P.C. [Zentrum fuer Anatomie und Zellbiologie der Medizinischen Universitaet Wien (Austria). Arbeitsgruppe Integrative Morphologie; Helmer, H.; Langer, M. [Medizinische Universitaet Wien (Austria). Klinik fuer Frauenheilkunde; Balassy, C.; Prayer, D. [Medizinische Universitaet Wien (Austria). Klinik fuer Radiodiagnostik

    2006-02-15

    A well-organized interplay between many molecular factors as well as mechanical forces influence fetal lung development. At the end of this complex process a sufficiently sized and structurally mature organ should ensure the postnatal survival of the newborn. Besides prenatal ultrasonography, magnetic resonance imaging (MRI) can now be used to investigate normal and pathological human lung growth in utero. Oligohydramnios, due to premature rupture of membranes (PROM), is an important risk factor for compromised fetal lung growth. In these situations MR volumetry can be used to measure the size of the fetal lung quite accurately. Together with the evaluation of lung signal intensities on T2-weighted sequences, fetuses with pulmonary hypoplasia can be readily detected. (orig.) [German] Die fetale Lungenentwicklung wird einerseits durch eine Vielzahl molekularer Faktoren und andererseits durch mechanisch-physiologische Kraefte beeinflusst. Ein geordnetes Zusammenspiel dieser Mechanismen fuehrt zu einem ausreichend grossen und strukturell reifen Organ, das sofort nach der Geburt das Ueberleben des Neugeborenen sicherstellt. Neben der praenatalen Ultraschalluntersuchung bietet nun auch die Magnetresonanztomographie (MRT) die Moeglichkeit, die normale und pathologische fetale Lungenentwicklung zu untersuchen. Ein wesentlicher Risikofaktor fuer eine Beeintraechtigung der Lungenentwicklung ist die verminderte Fruchtwassermenge nach vorzeitigem Blasensprung. In diesen Faellen kann die MR-Volumetrie dazu eingesetzt werden, die Groesse der fetalen Lungen relativ genau zu bestimmen. Gemeinsam mit der Beurteilung der MR-Signalintensitaeten des Lungengewebes auf T2-gewichteten Sequenzen koennen Feten mit hypoplastischen Lungen mit zunehmender Sicherheit bereits praenatal identifiziert werden. (orig.)

  20. Working memory in volunteers and schizophrenics using BOLD fMRI; Das Arbeitsgedaechtnis bei Gesunden und bei Schizophrenen: Untersuchungen mit BOLD-fMRT

    Energy Technology Data Exchange (ETDEWEB)

    Giesel, F.L. [Deutsches Krebsforschungszentrum (DKFZ) Heidelberg, Abteilung Radiologie (Germany); Deutsches Krebsforschungszentrum (DKFZ), Abteilung Radiologie, Heidelberg (Germany); Hohmann, N. [Deutsches Krebsforschungszentrum (DKFZ) Heidelberg, Abteilung Radiologie (Germany); Psychiatrische Universitaetsklinik Heidelberg, Sektion Gerontopsychiatrie (Germany); Seidl, U.; Kress, K.R.; Schoenknecht, P.; Schroeder, J. [Psychiatrische Universitaetsklinik Heidelberg, Sektion Gerontopsychiatrie (Germany); Kauczor, H.-U.; Essig, M. [Deutsches Krebsforschungszentrum (DKFZ) Heidelberg, Abteilung Radiologie (Germany)

    2005-02-01

    Functional magnetic resonance imaging uses the blood oxygen level-dependent effect (BOLD MRI) for noninvasive display of cerebral correlatives of cognitive function. The importance for the understanding of physiological and pathological processes is demonstrated by investigations of working memory in schizophrenics and healthy controls. Working memory is involved in processing rather than storage of information and therefore is linked to complex processes such as learning and problem solving. In schizophrenic psychosis, these functions are clearly restricted. Training effects in the working memory task follow an inverse U-shape function, suggesting that cerebral activation reaches a peak before economics of the brain find a more efficient method and activation decreases. (orig.) [German] Die funktionelle Magnetresonanztomographie (fMRT) nutzt den ''blood oxygen level dependent effect'' (BOLD-Effekt) zur nichtinvasiven Darstellung zerebraler Korrelate kognitiver Funktionen. Die Bedeutung dieses Verfahrens fuer das Verstaendnis physiologischer und pathologischer Prozesse wird anhand von Untersuchungen zum Arbeitsgedaechtnis bei Schizophrenen und gesunden Kontrollpersonen verdeutlicht. Das Arbeitsgedaechtnis dient weniger der Speicherung, sondern vielmehr der Verarbeitung von Informationen und ist deshalb in komplexe Prozesse wie Lernen und Problemloesen eingebunden. Im Rahmen schizophrener Psychosen kommt es zu einer deutlichen Einschraenkung dieser Funktionen. Erwartungsgemaess zeigen sich unter Durchfuehrung eines Arbeitsgedaechtnisparadigmas Unterschiede in der zerebralen Aktivitaet, die jedoch bei den Erkrankten unter Therapie prinzipiell reversibel sind. Von Interesse sind auch Trainingseffekte bei Gesunden, wobei eine verminderte Aktivierung nach Training auf eine ''Oekonomisierung'' schliessen laesst. (orig.)

  1. Frauen. Kultur. Mittel- und Osteuropa oder: Über den langsamen Einzug der gender studies in die slawistischen Kulturwissenschaften Women. Culture. Middle and Eastern Europe or: On the Slow Introduction of gender studies into the Slavonic Cultural Sciences

    Directory of Open Access Journals (Sweden)

    Barbara Wurm

    2001-03-01

    Full Text Available Der vorliegende Sammelband, entstanden anläßlich einer Konferenz, die im September 1997 vom Institut für Slawistik der Universität Innsbruck in Zusammenarbeit mit der österreichischen UNESCO-Kommission veranstaltet wurde, untersucht aus soziologischer, kulturhistorischer, literatur- und filmwissenschaftlicher Perspektive verschiedenste Aspekte der Institutionalisierung und Repräsentation von „Frauen in der Kultur“ Mittel- und Osteuropas.This anthology, the result of a conference organized in September 1997 by the Institute for Slavonic studies at the University of Innsbruck in co-operation with the Austrian UNESCO commission, examines various aspects of the institutionalization and representation of women in Middle and Eastern European culture from a sociological and cultural historical perspective and from that of literary and film sciences.

  2. Magnetic resonance imaging (MRI) of liver and brain in haematologic-organic patients with fever of unknown origin; Magnetresonanztomographie (MRT) der Leber und des Gehirns bei haematologisch-onkologischen Patienten mit Fieber unbekannter Ursache

    Energy Technology Data Exchange (ETDEWEB)

    Heussel, C.P.; Kauczor, H.U.; Poguntke, M.; Schadmand-Fischer, S.; Mildenberger, P.; Thelen, M. [Mainz Univ. (Germany). Klinik und Poliklinik fuer Radiologie; Heussel, G. [Mainz Univ. (Germany). 3. Medizinische Klinik und Poliklinik

    1998-08-01

    To examine the advantage of liver and brain MRI in clinically anomalous haematological patients with fever of unknown origin. Material and Methods: Twenty liver MRI (T{sub 2}-TSE, T{sub 2}-HASTE, T{sub 1}-FLASH{+-}Gd dynamic) and 16 brain MRI (T{sub 2}-TSE, FLAIR, T{sub 1}-TSE{+-}Gd) were performed searching for a focus of fever with a suspected organ system. Comparison with clinical follow-up. Results: suspected organ system. Comparison with clinical follow-up. Results: A focus was detected in 11/20 liver MRI. Candidiasis (n=3), mycobacteriosis (n=2), relapse of haematological disease (n=3), graft versus host disease (n=1), non-clarified (n=2). The remaining 9 cases with normal MRI were not suspicious of infectious hepatic disease during follo-wup. In brain MRI, 3/16 showed a focus (toxoplasmosis, aspergillosis, mastoiditis). Clinical indication for an infectious involvement of the brain was found in 4/16 cases 2--5 months after initially normal brain MRI. No suspicion of an infectious involvement of brain was present in the remaining 9/16 cases. Conclusion: In case of fever of unknown origin and suspicion of liver involvement, MRI of the liver should be performed due to data given in literature and its sensitivity of 100%. Because of the delayed detectability of cerebral manifestations, in cases of persisting suspicion even a previously normal MRI of the brain should be repeated. (orig.) [Deutsch] Untersuchung des Nutzens der MRT der Leber und des Gehirns bei klinisch auffaelligen haematologischen Patienten mit Fieber unbekannter Ursache. Material und Methoden: Es wurden 20 MRT der Leber (T{sub 2}-TSE, T{sub 2}-HASTE, T{sub 1}-FLASH{+-}Gd dynamisch) und 16 MRT des Gehirns (T{sub 2}-TSE, FLAIR, T{sub 1}-TSE{+-}Gd) zur Fokussuche bei Infektionsverdacht und Organhinweisen durchgefuehrt. Es erfolgte der Abgleich mit dem weiteren klinischen Verlauf. Ergebnisse: 11/20 MRT-Untersuchungen der Leber zeigten einen Herdbefund: Candidiasis (n=3), Mykobakteriose (n=2

  3. Vorrichtung zur Thermokoagulation mittels Laserstrahlung

    OpenAIRE

    Wehner, Martin; Aden, Mirko

    2012-01-01

    The apparatus has diode lasers (2,4) which emit laser radiation with different central wavelength. The laser radiations from diode lasers are superimposed with each other. A control device (12) is provided for controlling laser power of diode laser. The thermal coagulation process is performed with respect to simultaneous emission of laser radiation from diode laser in processing mode. The ratio of laser power of diode laser in processing mode is changed according to specific pattern and/or a...

  4. DMSA-scintigraphy in paediatrics: is the evaluation of the geometric mean necessary for the calculation of the differential renal function?; Partialfunktionsberechnung der Nieren mit DMSA in der Paediatrie: ist fuer die Bestimmung das geometrische Mittel notwendig?

    Energy Technology Data Exchange (ETDEWEB)

    Porn, U.; Alalp, S.; Fischer, S.; Dresel, S. [Klinik und Poliklinik fuer Nuklearmedizin, Klinikum der Ludwig-Maximilians-Univ. Muenchen (Germany); Rossmueller, B. [Inst. fuer Radiologische Diagnostik, Klinikum der Ludwig-Maximilians-Univ. Muenchen (Germany); Hahn, K. [Klinik und Poliklinik fuer Nuklearmedizin, Klinikum der Ludwig-Maximilians-Univ. Muenchen (Germany); Inst. fuer Radiologische Diagnostik, Klinikum der Ludwig-Maximilians-Univ. Muenchen (Germany)

    2001-08-01

    cases with an obvious anatomical abnormality. (orig.) [German] Bei der statischen Nierenfunktionsszintigraphie mit Tc-99m-Dimercaptobernsteinsaeure (DMSA) wird zur moeglichst exakten Bestimmung der seitengetrennten Partialfunktion (PF) die Berechnung des geometrischen Mittels aus dorsaler und ventraler Projektion empfohlen. Ziel unserer Untersuchung war es, die allein aus der dorsalen Projektion ermittelte Partialfunktion (PF{sub dors}) mit der aus dem geometrischen Mittel berechneten PF (PF{sub geom}) zu vergleichen, um die Notwendigkeit der zusaetzlichen ventralen Projektion zu ueberpruefen. Methode: Es wurden 164 DMSA-Untersuchungen von 151 Kindern (86 w, 65 m) mit einem Alter von 16 d bis 16 a (4,7 {+-} 3,9 a) ausgewertet. Die Akquisition erfolgte mit einer Doppelkopfkamera aus ventraler und dorsaler Projektion (Picker Prism 2000 XP, LEUHR, Matrix: 256 x 256, 300 kcts/view, Zoom: 1,6-2,0). Mittels ROI-Auswertung wurden die Hintergrund-korrigierten Zaehlraten der beiden Nieren von ventral und dorsal bestimmt und die dorsalen Zaehlratenverhaeltnisse mit dem geometrischen Mittel (SQR[Cts{sub dors} x Cts{sub ventr}]) verglichen. Ergebnisse: Die PF{sub dors} ergab statistisch signifikant niedrigere Werte fuer die rechte Niere (bzw. entsprechend hoehere Werte fuer die linke Niere) im Vergleich zur PF{sub geom} (p<0,01). Die mittlere Differenz zwischen der PF{sub geom} und der PF{sub dors} betrug 1,5 {+-} 1,4%. Nur in 6/164 Faellen (3,7%) ergab sich ein Unterschied von {>=}5% (5,0-9,5%). Bei 3 dieser 6 Faelle lag die mit der PF{sub dors} unterschaetzte Niere (2 x links, 1 x rechts) kaudal dystop. Die uebrigen 3 Patienten mit einer Differenz von >5% zeigten keine Lage- oder Strukturanomalie. Schlussfolgerung: Die Berechnung der Partialfunktion ausschliesslich aus den dorsalen Projektionen fuehrt im Vgl. zur Berechnung durch das geometrische Mittel zu einer Unterschaetzung der PF der rechten Niere im Vergleich zur linken Niere. Dieser Effekt fuehrt jedoch bei orthotop

  5. Functional MRI 2.0. {sup 23}Na and CEST imaging; Funktionelle MRT 2.0. {sup 23}Na- und CEST-Bildgebung

    Energy Technology Data Exchange (ETDEWEB)

    Haneder, S. [Uniklinik Koeln, Institut fuer Diagnostische und Interventionelle Radiologie, Koeln (Germany); Konstandin, S. [Universitaet Bremen, MR-Bildgebung und -Spektroskopie, Fachbereich 1 (Physik/Elektrotechnik), Bremen (Germany); Fraunhofer MEVIS, Institut fuer Bildgestuetzte Medizin, Bremen (Germany)

    2016-02-15

    In recent years the purely morphological magnetic resonance imaging (MRI) has been increasingly flanked by so-called functional imaging methods, such as diffusion-weighted imaging (DWI), to obtain additional information about tissue or pathological processes. This review article presents two MR techniques that can detect physiological processes in the human body. In contrast to all other functional MR imaging techniques, which are based on hydrogen protons, the first technique presented (X-nuclei imaging) uses the spin of other nuclei for imaging and consequently allows a completely different insight into the human body. In this article X-nuclei imaging is focused on sodium ({sup 23}Na) MRI because it currently represents the main focus of research in this field due to the favorable MR properties of sodium. The second MR technique presented is the relatively novel chemical exchange saturation transfer (CEST) imaging that can detect exchange processes between protons in metabolites and protons in free water. The first part of this article introduces the basic technical principles, problems, advantages and disadvantages of these two MR techniques, whereas the second part highlights the potential clinical applications. Examples illustrate several potential applications in neuroimaging (e. g. stroke and tumors), musculoskeletal imaging (e. g. osteoarthritis and degenerative processes) and abdominal imaging (e. g. kidneys and hypertension). Both techniques inherently contain an incredible potential for future imaging but are still on the threshold of clinical use and are currently under evaluation in many university centers. (orig.) [German] In den letzten Jahren wird die reine morphologische Magnetresonanztomographie (MRT) zunehmend von sogenannten funktionellen Bildgebungsmethoden, wie der diffusionsgewichteten Bildgebung (''diffusion-weighted imaging'', DWI), flankiert, um zusaetzliche Informationen ueber Gewebe oder pathologische Prozesse zu

  6. Indirect MR venography: contrast medium protocols, postprocessing and combination in diagnosing pulmonary emboli with MRI; Indirekte MR-Phlebografie: Kontrastmittelprotokolle, Nachverarbeitung und Kombination mit Lungenemboliediagnostik in der MRT

    Energy Technology Data Exchange (ETDEWEB)

    Kluge, A.; Bachmann, G. [Diagnostische Radiologie, Kerckhoff-Klinik, Bad Nauheim (Germany); Rominger, M. [Diagnostische Radiologie, Phillips-Univ. Marburg (Germany); Schoenburg, M. [Herzchirurgie, Kerckhoff-Klinik, Bad Nauheim (Germany)

    2004-07-01

    Purpose: Integration of MR venography in a comprehensive MR imaging protocol in patients with suspected pulmonary embolism (PE) and evaluation of contrast media dosage, timing and postprocessing for diagnostic accuracy. Materials and Methods: Fortyeight consecutive inpatients with suspected PE or deep vein thrombosis were examined by MR venography according to one of the following protocols: protocol I: MR venography only, 0.25 mmol/kg bodyweight (BW) Gadopentate dimeglumine(Gd-DTPA) as single dose, bolus timing; protocol II: MR angiography of pulmonary arteries with a cumulative dosage of 0.25 mmol/kg contrast media, modification of coil setting for MR venography without further contrast media application; protocol III: as protocol II but with 0.125 mmol/kg BW, followed by MR venography. Signal-to-noise ratio, contrast-to-noise ratio, number of definable vascular segments and image quality were evaluated. The results were compared to conventional bilateral venography. Results: All MR venography examinations were of diagnostic quality and the examination time was below 10 min. MR venography could be performed in all 48 patients comparted to 43 of 48 patients for conventional venography. Significantly more superficial and deep veins of the leg could be visualized by MR venography (94% compared to 83% for conventional venography). Sensitivity and specificity were 100% and 92%, respectively. Quality differed significantly between 0.125 mmol/kg (protocol III) and 0.25 mmol/kg Gd-DTPA (protocols I and II) while timing did not influence quality (protocol I vs. II). (orig.) [German] Ziel: Integration der MR-Phlebografie in ein umfassendes Konzept der MRT-Diagnostik bei Verdacht auf Lungenembolie (LE). Untersuchung des Einflusses von Kontrastmittelmenge, -bolusform und Verzoegerungszeit sowie der Nachverarbeitung auf die diagnostische Qualitaet von MR-Phlebografien. Material und Methode: Bei 48 konsekutiven stationaeren Patienten mit Verdacht auf Beinvenenthrombose (TVT

  7. Reduction of radiation dose by using digital luminescence radiography compared to conventional screen film system with grid cassette; Reduktion der Strahlendosis mittels Speicherfolienradiographie im Vergleich zum konventionellen Film-Folien-System mit Rasterkassette am Schaedelphantom

    Energy Technology Data Exchange (ETDEWEB)

    Heyne, J.P.; Merbold, H.; Neumann, R.; Freesmeyer, M.; Jonetz-Mentzel, L.; Kaiser, W.A. [Friedrich-Schiller-Univ. Jena, Inst. fuer Diagnostische und Interventionelle Radiologie (Germany); Sehner, J. [AGFA-Deutschland, Vertriebsgesellschaft (Germany)

    1999-07-01

    mittels RK und digital (ADC-70, Agfa) a.p. geroentgt. Bei konstanter Spannung wurde das mAs-Produkt stufenweise gesenkt und dabei die Eintrittsdosis mittels Halbleiterdetektor des Dosimax (Wellhoefer) ermittelt. 5 Untersucher beurteilten die Aufnahmen nach charakteristischen Bildmerkmalen, kritischen Strukturen, Ortsaufloesung und Bildkontrast. Ergebnisse: Die Eintrittsdosis betrug bei 73 kV/22 mAs konventionell (Rasterkassette) 0,432 mGy und digital 0,435 mGy. Bis zu einer durchschnittlichen Dosis von 71% (0,308 mGy; SD 0,050) waren die Aufnahmen sehr gut und bis zu einer durchschnittlichen Dosis von 31% (0,136 mGy; SD 0,065) ausreichend beurteilbar. Die erkennbaren Linienpaare/mm auf dem Bleistrichraster reduzierten sich dabei untersucherabhaengig bis zu 2 Stufen. Der Bildkontrast war sehr gut bis ausreichend. Die Akzeptanz der nachverarbeiteten Aufnahmen war individuell verschieden und erbrachte nur in hoeheren Dosisbereichen eine verbesserte Beurteilbarkeit der Knochenstrukturen und des Kontrastes. Schlussfolgerung: Fuer die ausreichende Beurteilbarkeit einer moeglichen Fraktur/der Nasennebenhoehlen/zur Vermessung kann die Dosis auf mindestens 56% (Durchmesser 31%; SD 14,9%)/40% (Durchmesser 27%; SD 9,3%)/18% (Durchmesser 14%; SD 4,4%) gesenkt werden. Mittels digitaler Radiografie wird damit bei 73 kV ein fragestellungsbezogenes mAs-Produkt moeglich und angegeben, so z.B. zum Frakturausschluss 73 kV/12,5 mAs und zur Schaedelvermessung 73 kV/4 mAs. (orig.)

  8. Inflammatory lesions of the spinal cord and the nerve roots in magnetic resonance imaging; Entzuendliche Erkrankungen des Rueckenmarks und der Nervenwurzeln in der MRT

    Energy Technology Data Exchange (ETDEWEB)

    Sartoretti-Schefer, S. [Inst. fuer Neuroradiologie, Universitaetsspital Zuerich (Switzerland); Wichmann, W. [Inst. fuer Neuroradiologie, Universitaetsspital Zuerich (Switzerland); Valavanis, A. [Inst. fuer Neuroradiologie, Universitaetsspital Zuerich (Switzerland)

    1996-11-01

    und immunkompetenten Patienten eingeteilt, was teilweise Rueckschluesse auf die zugrundeliegende Aetiologie erlaubt. Der immunsupprimierte Patient leidet vor allem an viralen (Herpes simplex, Herpes zoster, Zytomegalie, HIV-Virus) sowie an bakteriellen (Tuberkulose, selten Syphilis), aber nur selten an parasitaeren Infektionen. Der immunkompetente Patient erkrankt vor allem an bakteriellen Infektionen (Borreliose) sowie an immunologisch bedingten entzuendlichen Erkrankungen (Sarkoidose) und an demyelinisierenden Laesionen. Haeufig ist auch die idiopathische Myelitis. Virale Infektionen sind selten. Die MRT-Morphologie der entzuendlichen Laesionen wird durch sekundaere ischaemische und demyelinisierende Veraenderungen kompliziert, wodurch die Differentialdiagnose sehr erschwert sein kann, da das gesamte Spektrum von demyelinisierenden bzw. ischaemischen und entzuendlichen Erkrankungen miteinbezogen werden muss. Zudem koennen auch tumoroese Prozesse eine Myelitis bzw. Radikulitis nachahmen. (orig.)

  9. Assessment of hemodynamic changes in patients with renal artery stenosis by means of the cine MR phase-contrast technique; Einstufung haemodynamischer Veraenderungen bei Nierenarterienstenosen mittels MR-Cine-Phasenkontrastflussmessungen

    Energy Technology Data Exchange (ETDEWEB)

    Schoenberg, S.O.; Knopp, M.V.; Bock, M.; Essig, M.; Hawighorst, H.; Zuna, I.; Schad, L.; Kaick, G. van [Deutsches Krebsforschungszentrum, Heidelberg (Germany). Forschungsschwerpunkt Radiologische Diagnostik und Therapie; Kallinowski, F.; Allenberg, J.R. [Chirurgische Universitaetsklinik, Heidelberg (Germany). Sektion Gefaesschirurgie; Just, A. [Heidelberg Univ. (Germany). 1. Physiologisches Inst.

    1997-08-01

    Purpose: To evaluate the use of high-temporal resolution cine MR phase-contrast flow measurements for assessment of flow dynamics in renal artery stenosis (RAS). Material and methods: In a dog model, cine MR flow measurements were validated by comparing the MR flow data to an invasive transit-time ultrasound reference technique for different degrees of RAS. Cardiac-gated MR flow curves were recorded in 56 renal arteries of 28 patients with a temporal resolution of at least 32 ms. In all cases RAS was confirmed by digital subtraction angiography (DSA). Abnormalities of flow dynamics were assessed in the calculated flow curves using the MR parameters mean flow, maximum velocity, and time to systolic maximum. Results: By means of the MR blood flow paremeters high-grade stenoses (>50%, n=23) were detected with sensitivity of 100% and specificity of 94% with reference to DSA. The overall differentiation between stenoses (n=37) and non-stenosed vessels (n=19) revealed a sensitivity of 87% and a specificity of 100%. Conclusion: Analysis of cardiac-gated MR flow curves provides a non-invasive method to assess the hemodynamic significance of RAS and thus allows a functional evaluation in relation to the morphologic characteristics of the stenosis. (orig.) [Deutsch] Ziel der Untersuchung war die Beurteilung der Haemodynamik bei Nierenarterienstenosen mittels Cine-MR-Phasenkontrastflussmessungen. In einem Hundemodell wurde die Cine-MR-Flussmessung validiert, indem fuer unterschiedliche Stenosegrade Vergleichsmessungen mit einer invasiven Transitzeit-Ultraschallreferenztechnik durchgefuehrt wurden. EKG-getriggerte MR-Flusskurven wurden bei 28 Patienten in 56 Nierenarterien mit einer Zeitaufloesung von mindestens 32 ms aufgenommen. Alle Nierenarterienstenosen wurden mittels digitaler Subtraktionsangiographie gesichert. Stoerungen in der renalen Haemodynamik wurden anhand der berechneten MR-Flusskurven mit Hilfe der Parameter `Mittelfluss, `maximale Geschwindigkeit` und `Zeit

  10. Selected clinically established and scientific techniques of diffusion-weighted MRI. In the context of imaging in oncology; Ausgewaehlte klinisch etablierte und wissenschaftliche Techniken der diffusionsgewichteten MRT. Im Kontext der onkologischen Bildgebung

    Energy Technology Data Exchange (ETDEWEB)

    Freitag, M.T.; Bickelhaupt, S.; Ziener, C.; Mosebach, J.; Schlemmer, H.P. [Deutsches Krebsforschungszentrum, Abteilung fuer Radiologie, Heidelberg (Germany); Meier-Hein, K. [Deutsches Krebsforschungszentrum, Abteilung fuer medizinische Informatik, Heidelberg (Germany); Radtke, J.P. [Deutsches Krebsforschungszentrum, Abteilung fuer Radiologie, Heidelberg (Germany); Universitaetsklinik Heidelberg, Abteilung fuer Urologie, Heidelberg (Germany); Kuder, T.A.; Laun, F.B. [Deutsches Krebsforschungszentrum, Abteilung fuer Medizinische Physik in der Radiologie, Heidelberg (Germany)

    2016-02-15

    Diffusion-weighted imaging (DWI) is a magnetic resonance imaging (MRI) technique that was established in the clinical routine primarily for the detection of brain ischemia. In the past 15 years its clinical use has been extended to oncological radiology, as tumor and metastases can be depicted in DWI due to their hypercellular nature. The basis of DWI is the Stejskal-Tanner experiment. The diffusion properties of tissue can be visualized after acquisition of at least two diffusion-weighted series using echo planar imaging and a specific sequence of gradient pulses. The use of DWI in prostate MRI was reported to be one of the first established applications that found its way into internationally recognized clinical guidelines of the European Society of Urological Radiology (ESUR) and the prostate imaging reporting and data system (PI-RADS) scale. Due to recently reported high specificity and negative predictive values of 94 % and 92 %, respectively, its regular use for breast MRI is expected in the near future. Furthermore, DWI can also reliably be used for whole-body imaging in patients with multiple myeloma or for measuring the extent of bone metastases. New techniques in DWI, such as intravoxel incoherent motion imaging, diffusion kurtosis imaging and histogram-based analyses represent promising approaches to achieve a more quantitative evaluation for tumor detection and therapy response. (orig.) [German] Die diffusionsgewichtete Bildgebung (''diffusion-weighted imaging'', DWI), ein Verfahren aus der Magnetresonanztomographie (MRT), wurde in der klinischen Routine primaer fuer die Detektion von Schlaganfaellen etabliert. Der Einsatz dieser Methode hat in den letzten 15 Jahren auch fuer die onkologische Diagnostik stark zugenommen, da Tumoren und Metastasen aufgrund ihrer hochzellulaeren Zusammensetzung in der DWI sehr gut sichtbar gemacht werden koennen. Basis der diffusionsgewichteten Bildgebung ist das Experiment nach Stejskal-Tanner. Hier

  11. PET-CT and PET-MRI of the prostate. From {sup 18}F-FDG to {sup 68}Ga-PSMA; PET-CT/-MRT der Prostata. Von {sup 18}F-FDG zu {sup 68}Ga-PSMA

    Energy Technology Data Exchange (ETDEWEB)

    Knorr, K.; Eiber, M.; Scheidhauer, K. [Technische Universitaet Muenchen, Nuklearmedizinische Klinik und Poliklinik, Klinikum rechts der Isar, Muenchen (Germany); Maurer, T. [Technische Universitaet Muenchen, Urologische Klinik und Poliklinik, Klinikum rechts der Isar, Muenchen (Germany); Wester, H.J. [Technische Universitaet Muenchen, Pharmazeutische Radiochemie, Garching (Germany)

    2017-08-15

    In the last few years nuclear medical diagnostics have experienced a unprecedented renaissance in the diagnostics of prostate cancer, due to the availability of hybrid imaging with positron emission tomography computed tomography (PET/CT), PET magnetic resonance imaging (PET/MRI) and single photon emission computed tomography (SPECT) CT as well as the development of prostate-specific radiopharmaceuticals. The use of fluorodeoxyglucose (FDG), which has been successfully implemented for many years in PET diagnostics, is only helpful in dedifferentiated tumors due to the biological characteristics of prostate cancer. New specific radiopharmaceuticals, such as choline-derivatives, which are incorporated into the prostate cancer cell and built into the cell membrane as well as the recently developed highly specific ligands for prostate-specific membrane antigen (PSMA) are revolutionizing prostate cancer imaging and (re-) staging. The {sup 68} Ga-labeled PSMA ligands for PET-CT and PET-MRI are highly specific tracers for primary diagnostics and detection of metastases of prostate carcinoma. In risk patients, which includes patients with intermediate and high-risk tumors, they have largely replaced choline-based PET-CT, especially in the case of very low PSA values <0.5 ng/ml in the diagnostics of recurrence. The use in the primary diagnostics as PET-MRI, also in combination with multiparametric MRI (mpMRI), is promising with respect to early diagnostics and image fusion-assisted biopsy as well as surgery and irradiation planning. (orig.) [German] Die nuklearmedizinische Diagnostik hat in den letzten Jahren bei der Bildgebung des Prostatakarzinoms eine rasante Entwicklung erlebt, sowohl aufgrund der verfuegbaren Hybridbildgebung mit der Positronenemissionstomographie(PET)-CT, PET-MRT sowie der Single-photon-emission-computed-tomography(SPECT)-CT als auch durch die Entwicklung prostataspezifischer Radiopharmaka. Die in der PET-Diagnostik seit Jahren erfolgreich eingesetzte

  12. Therapy by electromagnetic wave of millimeter energy range (EFH-therapy, MRT, IWT). Scientific and practical materials on the use of physical factors in clinical and health resort practice

    International Nuclear Information System (INIS)

    Samosyuk, I.Z.; Fisenko, L.I.; Kolesnik, K.Eh.; Chukhraev, N.V.; Shimkov, G.E.

    1998-01-01

    Problems of extremely high frequency (EHF) therapy, microwave resonance therapy (MRT) and information-wave therapy (IWT) are considered. Possibilities of electromagnetic waves in millimeter energy range use in clinical and health resort practice are systematized. Recommendations on their use in treatment of different diseases are given. The main principles of selection of zones for meridian correction with the help of electromagnetic waves in millimeter energy range are exposed. The results of EFH-therapy clinical use indicate the possibility of its application practically in all cases, since positive results were obtained in most cases. The recommendations are prepared with account of possibilities and parameters of the apparatus ''MIT-1'' for reflexotherapy which was designed and produced by the Medical Innovative Centre in Kiev

  13. Influence of platform screen doors on energy consumption of the environment control system of a mass rapid transit system: case study of the Taipei MRT [mass rapid transit] system

    Energy Technology Data Exchange (ETDEWEB)

    Shih-Cheng Hu; Jen-Ho Lee [National Taipei University of Technology, Taipei (China). Dept. of Air Conditioning and Refrigeration Engineering

    2004-03-01

    This investigation studies how platform screen doors (PSD) affect the energy consumption of the environmental control system of a mass rapid transit (MRT) system in Taipei. The environmental parameter simulation was conducted using the subway environmental simulation (SES) program, while the associated air conditioning (A/C) cooling load was predicted with the carrier E20-II program. Results show that PSD can significantly decrease average and peak cooling load, thus reducing the capacity/size of cooling equipment and allowing the chiller cooling load to be abridged. However, electricity consumption by ventilation equipment increases notably when PSD are used, particularly the electricity consumption by the under platform exhaust (UPE) fan, and thus, ultimately, little difference exists in the overall energy consumption with and without UPE. (author)

  14. Experimental determination of the electronic properties of application-relevant interfaces of organic semiconductors by means of photoelectron spectroscopy; Experimentelle Bestimmung der elektronischen Eigenschaften anwendungsrelevanter Grenzflaechen organischer Halbleiter mittels Photoelektronenspektroskopie

    Energy Technology Data Exchange (ETDEWEB)

    Grobosch, Mandy

    2009-07-01

    This thesis under the titel Experimental Determination of the Electronic Properties of Application-relevant Interfaces of Organic Semiconductors by means of Photoelectron Spectroscopy was drawn up at the Leibniz Institute for Solid-State and Materials Research (IFW) Dresden at the Institute for Solid-State Research (IFF) under the maintenance of Prof. Dr. B. Buechner. To the scientific study hereby came two types of application-relevant interfaces. On the one hand the influence of the electrode preparation under normal conditions by means of ex-situ purification procedures in comparison to in-situ prepared contacts on the electronic behaviour of the organic semiconductor sexithiophene on interfaces to metallic substrates was studied. As substrate materials hereby the metals silver, palladium, gold, and platinum came to application. In a second study the interfaces of the organic semiconductors sexithiophene and copper(II)-phthalocyanine in contact to thin films of the transition-metal oxide La{sub 0.7}Sr{sub 0.3}MnO{sub 3} were studied. Also here a comparing study for ex-situ and in-situ purificated La{sub 0.7}Sr{sub 0.3}MnO{sub 3} contacts was performed. The films applied for this were fabricated in the IWF Dresden at the Institute for Metallic Materials (IMW). Also in the framework of these studies the influence of oxygen on the electronic and chemical behaviour on the interfaces held the spotlight. [German] Diese Dissertation unter dem Titel Experimentelle Bestimmung der elektronischen Eigenschaften anwendungsrelevanter Grenzflaechen organischer Halbleiter mittels Photoelektronenspektroskopie wurde am Leibniz Institut fuer Festkoerper- und Werkstoffforschung (IFW) Dresden am Institut fuer Festkoerperforschung (IFF) unter der Betreuung von Prof. Dr. B. Buechner angefertigt. Zur wissenschaftlichen Untersuchung kamen hierbei zwei Typen anwendungsrelevanter Grenzflaechen. Zum einem wurde der Einfluss einer Elektrodenpraeparation unter Normalbedingungen mittels ex

  15. Gd-DTPA-enhanced T{sub 1}-weighted excretory MR urography after low-dose diuretic injection; T{sub 1}-gewichtete MR-Ausscheidungsurographie mittels Gd-DTPA und vorheriger niedrigdosierter Gabe eines Diuretikums

    Energy Technology Data Exchange (ETDEWEB)

    Nolte-Ernsting, C.; Buecker, A.; Adam, G.; Neuerburg, J.; Guenther, R.W. [Universitaetsklinikum der RWTH Aachen (Germany). Klinik fuer Radiologische Diagnostik

    1997-09-01

    Purpose: Assessment of the morphology of the urinary tract by gadolinium(Gd)-enhanced T{sub 1}-weighted MR-urography (MRU) and precontrast diuretic injection. Methods: MRU was performed in 5 patients using Gd-DTPA-enhanced coronal T{sub 1}-weighted 3D-gradient-echo sequences with different spatial resolution. Prior to contrast injection, 10 mg of furosemide were administered intravenously. Results: Secondary to the precontrast furosemide injection, the increase of the renal excretion rate allows complete visualisation of the entire collecting system within 10 minutes following Gd injection. Maximum intensity projections provide a three-dimensional overview of the ureters separate from the bladder. To achieve detailed anatomic imaging of the calices, both optimal distension and high resolution sequences are prerequisites which cannot be realized by means of survey urograms only. (orig./AJ) [Deutsch] Ziel: Darstellung der Morphologie der ableitenden Harnwege mittels T{sub 1}-gewichteter MR-Urographie (MRU) nach Gabe eines nierengaengigen Gadolinium(Gd)-Chelates und vorheriger Diuretikumapplikation. Methoden: Der Harntrakt von 5 Patienten wurde nach Injektion von Gd-DTPA mit koronaren T{sub 1}-gewichteten 3D-Gradienten-Echo-Sequenzen unterschiedlicher Ortsaufloesung untersucht. Vor der Kontrastmittelgabe wurden jeweils 10 mg Furosemid intravenoes verabreicht. Ergebnisse: Nach initialer Steigerung des Harnflusses durch Furosemidgabe wurden Uebersichtsurogramme mit vollstaendig durchzeichnenden Ureteren bereits 10 min nach Gd-Injektion erzielt. Maximumintensitaetsprojektionen ermoeglichten die Beurteilung des dreidimensionalen Verlaufes der Ureteren ohne Blasenueberlagerung. Eine genauere anatomische Darstellung der Nierenkelche erforderte neben einem guten Fuellungszustand eine moeglichst hohe Sequenzaufloesung, die mit Uebersichtsurogrammen allein nicht zu erreichen war. (orig./AJ)

  16. Development of new heterogeneous catalysts for the decomposition of methanol into hydrogen and carbon monoxide applying high throughput methods; Entwicklung neuer heterogener Katalysatoren zur Spaltung von Methanol in Wasserstoff und Kohlenmonoxid mittels Hochdurchsatz-Methoden

    Energy Technology Data Exchange (ETDEWEB)

    Weiss, Torsten

    2008-07-11

    The topic of this thesis has been the development of new heterogeneous catalysts for the decomposition of methanol into hydrogen and carbon monoxide. As an important constraint here, the content of noble metals of the catalysts should be as low as possible. High-throughput-methods were applied in some of the syntheses and experiments to accelerate the development, as, for example, the use of liquid based sol-gel syntheses and the examination of catalyst libraries by spatial resolution gas chromatography. This screening technique allowed to test up to 207 different substances during one single experiment. Then, different combinatorial strategies were applied. First, these methods led to a highly active and stable catalyst in the ternary system of Cu-Ni-Zn, which showed high conversion and selectivity comparable to an industrial reference catalyst. Its activity during an 18 hour long term run was constant in contrast to the reference. Second, an additional approach starting from a broader variety of elements led to a Ce- Ru- and to a Cr-Ru-catalyst. Both of them were highly active in short term experiments, but lost their outstanding performances during long term runs. (orig.) [German] Die vorliegende Arbeit befasste sich mit der Entwicklung neuer heterogener Katalysatoren fuer die Spaltung von Methanol zu Wasserstoff und Kohlenmonoxid, die einen moeglichst geringen Gehalt an Edelmetallen aufweisen sollten. Um diesen Prozess zu beschleunigen, wurden in einem Teil der Synthesen und Experimente Hochdurchsatzmethoden verwendet. Neben der Roboter gestuetzten Sol-Gel-Synthese umfasste dies die Untersuchung von Katalysatorbibliotheken mittels ortsaufgeloester Gaschromatographie, die es ermoeglichte, in einem Experiment bis zu 207 verschiedene Substanzen auf ihre katalytische Aktivitaet zu testen. Unter Anwendung verschiedener kombinatorischer Strategien wurde zunaechst ein sehr aktiver und stabiler Katalysator im ternaeren Cu-Ni-Zn-System entdeckt. Neben Umsaetzen und

  17. Metal recovery via geobiotechnology; Metallgewinnung mittels Geobiotechnologie

    Energy Technology Data Exchange (ETDEWEB)

    Hedrich, Sabrina; Schippers, Axel [Bundesanstalt fuer Geowissenschaften und Rohstoffe (BGR), Hannover (Germany). Fachbereich Geochemie der Rohstoffe

    2017-02-15

    Specialized acidophilic bacteria and archaea are able to extract valuable metals such as copper, gold, cobalt, nickel, zinc, and uranium from sulfide ores. This process is known as bioleaching and its application in the mining industry as biomining. Laboratory studies also demonstrated bioleaching of oxide ores such as laterites and of mining residues such as mine tailings as well as metal recycling from waste (secondary mining). Metals being leached have to be recovered from acidic polymetallic solutions (mine and process waters) which is possible via biosorption or biomineralisation.

  18. Kavitationsdetektion mittels self-sensing-ultraschallwandler

    OpenAIRE

    Bornmann, Peter; Hemsel, Tobias; Sextro, Walter; Memoli, Gianluca; Hodnett, Mark; Zeqiri, Bajram; Bornmann Peter; Hemsel Tobias; Sextro Walter; Memoli Gianluca; Hodnett Mark; Zeqiri Bajram

    2015-01-01

    Many processes in chemistry can be enhanced by ultrasound assistance. In many cases ultrasound induced cavitation is the main reason for these enhancements. Therefore, it is desired to quantify cavitation activity during the process to optimize sonication for various processes and monitor cavitation activity throughout the process. One possibility to monitor cavitation activity is to measure the acoustic emissions of oscillating and collapsing cavitation bubbles by hydrophones in the liquid. ...

  19. VIBE with parallel acquisition technique - a novel approach to dynamic contrast-enhanced MR imaging of the liver; VIBE mit paralleler Akquisitionstechnik - eine neue Moeglichkeit der dynamischen kontrastverstaerkten MRT der Leber

    Energy Technology Data Exchange (ETDEWEB)

    Dobritz, M.; Radkow, T.; Bautz, W.; Fellner, F.A. [Inst. fuer Diagnostische Radiologie, Friedrich-Alexander-Univ. Erlangen-Nuernberg (Germany); Nittka, M. [Siemens Medical Solutions, Erlangen (Germany)

    2002-06-01

    Leberlaesionen zu sammeln. Material und Methoden: 10 konsekutive Patienten mit verschiedenen pathologischen Befunden (HCC, Haemangiome, Metastasen, Zysten, Adenome) wurden an einem 1.5 T MRT-System untersucht. Zur Anwendung kamen folgende Sequenzen: T{sub 2} TSE und T{sub 1} FLASH nativ, nach Gadolinium-Gabe 6 VIBE-Sequenzen mit iPAT (TR/TE/Matrix/Partitionsdicke/Akquisitionszeit: 6.2 ms/3.2 ms/256 x 192/4 mm/13 s) sowie T{sub 1} FLASH mit Fettsaettigung. Zwei Untersucher beurteilten im Konsensus die einzelnen Sequenzen hinsichtlich Anzahl und Dignitiaet der Laesionen. Ergebnisse: Die VIBE-Sequenz zeigte sich ueberlegen in der Detektion arteriell hyperperfundierter Laesionen mit insgesamt 33 erkannten Herden. In der T{sub 2}-gewichteten TSE-Sequenz wurden 21 und in der nativen T{sub 1}-gewichteten GRE-Sequenz 20 Herde gefunden. Die diagnostische Sicherheit stieg in der VIBE-Sequenz gegenueber den anderen Sequenzen deutlich an. Zusammenfassung: Die VIBE-Sequenz mit iPAT ermoeglicht eine MRT der Leber in hoher oertlicher und zeitlicher Aufloesung, wodurch dynamische Kontrastinformationen ueber das gesamte Organ ermoeglicht werden. Dadurch koennte eine Verbesserung der Detektion fokaler Laesionen erreicht werden. (orig.)

  20. New aspects of MRI for diagnostics of large vessel vasculitis and primary angiitis of the central nervous system; Neue Aspekte der MRT-Bildgebung zur Diagnostik der Grossgefaessvaskulitiden sowie der primaeren Angiitis des zentralen Nervensystems

    Energy Technology Data Exchange (ETDEWEB)

    Saam, T.; Habs, M.; Cyran, C.C.; Grimm, J.; Reiser, M.F.; Nikolaou, K. [Klinikum der Ludwig-Maximilians-Universitaet Muenchen, Campus Grosshadern, Institut fuer Klinische Radiologie, Muenchen (Germany); Pfefferkorn, T. [Klinikum der Ludwig-Maximilians-Universitaet Muenchen, Campus Grosshadern, Klinik und Poliklinik fuer Neurologie, Muenchen (Germany); Schueller, U. [Klinikum der Ludwig-Maximilians-Universitaet Muenchen, Campus Grosshadern, Zentrum fuer Neuropathologie, Muenchen (Germany)

    2010-10-15

    der Gefaesswand zu, allerdings sind nur ausgewaehlte extrakranielle Gefaesse mit ausreichender Aufloesung schallbar. Da den Vaskulitiden primaer Veraenderungen der Gefaesswand zugrunde liegen und die gefundenen luminalen Veraenderungen in der Regel unspezifisch sind und auch bei anderen Erkrankungen auftreten koennen, sind die gebraeuchlichen Verfahren in ihrer Aussagekraft oft limitiert. Mit der hochaufgeloesten MRT der zervikalen und intrakraniellen Gefaesse steht eine viel versprechende neue Methode zur Verfuegung, die die entzuendlich veraenderte Gefaesswand nichtinvasiv und ohne Verwendung ionisierender Strahlen im Detail zu visualisieren vermag. In diesem Beitrag sollen die verwendeten Untersuchungsprotokolle vorgestellt und klinische Bildbeispiele gezeigt werden. Dabei sollen insbesondere die Grossgefaessvaskulitiden und die Vaskulitiden des ZNS behandelt werden. Zudem werden die haeufigsten radiologischen Differenzialdiagnosen demonstriert und andere bildgebende Methoden, wie PET/CT und Ultraschall, die ebenfalls zur Diagnostik der Vaskulitiden eingesetzt werden, diskutiert. (orig.)

  1. Spontaneous osteonecrosis of the knee joint: MR imaging before and after administration of gadopentetate-dimeglumine, comparison to CT, scintigraphy, and histology; Spontane Osteonekrose des Kniegelenkes: MRT im Vergleich zur CT, Szintigraphie und Histologie

    Energy Technology Data Exchange (ETDEWEB)

    Lang, P. [Dept. of Radiology, Univ. of California, San Francisco, CA (United States); Grampp, S. [Dept. of Radiology, Univ. of California, San Francisco, CA (United States); Vahlensieck, M. [Dept. of Radiology, Univ. of California, San Francisco, CA (United States)]|[Radiologische Klinik, Bonn Univ. (Germany); Mauz, M. [Dept. of Radiology, Univ. of California, San Francisco, CA (United States)]|[Radiologische Klinik, Universitaetsklinikum Rudolf Virchow, Freie Univ. Berlin (Germany); Steiner, E. [Universitaetsklinik fuer Radiodiagnostik, Wien (Austria); Schwickert, H. [Dept. of Radiology, Univ. of California, San Francisco, CA (United States)]|[Radiologische Klinik, Universitaetsklinik Mainz (Germany); Gindele, A. [Dept. of Radiology, Univ. of California, San Francisco, CA (United States); Felix, R. [Radiologische Klinik, Universitaetsklinikum Rudolf Virchow, Freie Univ. Berlin (Germany); Genant, H.K. [Dept. of Radiology, Univ. of California, San Francisco, CA (United States)

    1995-06-01

    Eight patients with spontaneous osteonecrosis of the knee joint underwent MR imaging before and after i.v. administration of Gd-DTPA. Nuclear scintigraphy was performed in all 8 patients, three patients also had CT scans of the knee area. Histologic correlation was available in three patients. Increased radionuclide uptake was observed in all patients. In one patient, however, scintigraphy showed increased radionuclide uptake consistent with ostenecrosis only in the medial femoral condyle, while MR imaging demonstrated osteonecrosis both in the medial as well as the lateral femoral condyles. MR demonstrated areas of low signal intensity on precontrast T{sub 1}-weighted images in the femoral condyle in all patients. All these areas showed high signal intensity on T{sub 2}-weighted images. On postcontrast T{sub 1}-weighted images, signal intensity increase was either homogeneous throughout the lesion or it was seen at the periphery of the lesion in a band-like pattern. Histologically, the areas of high signal intensity on T{sub 2}-weighted and on postcontrast T{sub 1}-weighted images corresponded to granulation tissue. (orig./MG) [Deutsch] Wir untersuchten acht Patienten mit einer spontanen Osteonekrose des Kniegelenkes mit der MRT. Ein Vergleich zum szintigraphischen Befund wurde bei allen 8 Patienten und zur CT bei drei Patienten angestellt. Eine histologische Korrelation war bei drei Patienten moeglich. Bei allen 8 Patienten zeigten die T{sub 1}-gewichteten MR-Tomographien Zonen mit reduzierter Signalintensitaet in den Kondylen, waehrend die Laesionen in den T{sub 2}-gewichteten Aufnahmen eine hoehere Signalintensitaet als das normale Knochenmark hatten. Nach Gabe von Gd-DTPA war entweder eine homogene Signalerhoehung oder eine bandfoermige Signalintensitaetszunahme in der Peripherie der Laesion zu sehen. Die Zonen mit hoher Signalintensitaet in der T{sub 2}-gewichteten Aufnahme oder mit Kontrastmittelanreicherung entsprachen histologisch Granulationsgewebe an der

  2. Detection of prostate carcinomas with T1-weighted dynamic contrast-enhanced MRI. Value of two-compartment model; Detektion von Prostatakarzinomen mit T1-gewichteter Kontrastmittel-unterstuetzter dynamischer MRT. Wertigkeit des Zweikompartimentemodells

    Energy Technology Data Exchange (ETDEWEB)

    Kiessling, F.; Lichy, M.; Farhan, N.; Delorme, S.; Kauczor, H.U. [Abteilung fuer Radiologie, Deutsches Krebsforschungszentrum (DKFZ) Heidelberg (Germany); Grobholz, R. [Abteilung fuer Pathologie, Universitaetsklinikum Mannheim (Germany); Heilmann, M. [Abteilung fuer Physik in der Radiologie, Deutsches Krebsforschungszentrum (DKFZ) Heidelberg (Germany); Michel, M.S.; Trojan, L. [Abteilung fuer Urologie, Universitaetsklinikum Mannheim (Germany); Werner, A.; Rabe, J. [Institut fuer Klinische Radiologie, Universitaetsklinikum Mannheim (Germany); Schlemmer, H.P. [Abteilung fuer Diagnostische Radiologie, Universitaetsklinikum Tuebingen (Germany)

    2003-06-01

    Aim The suitability of dynamic parameters of the two-compartment model for detecting prostate carcinomas and its correlation with tumor microvascular density were evaluated. The study included 43 patients with biopsy-proven prostate carcinoma: 28 were examined by 1.0-T MRI (Turbo-FLASH) and 15 by 1.5-T MRI (FLASH) with infusion of 0.1 mmol/kg Gd-DTPA. Signal time curves were parametrized with an open two-compartment model in amplitude and exchange rate constants (k{sub ep}).The microvascular density of resected prostate carcinomas was determined. The microvascular density in the tumors was significantly higher than in the adjacent healthy prostate tissue and correlated in both sequences with k{sub ep}. Prostate carcinomas of the peripheral zone were demarcated by amplitude and k{sub ep}. In the Turbo-FLASH sequence there was a significant difference between the tumor tissue and healthy peripheral zone in terms of k{sub ep} and in the FLASH sequence in terms of amplitude. Prostate carcinomas can be visualized with dynamic T1-weighted MR sequences using a two-compartment model. Moreover, the parameter k{sub ep} reveals the microvascular density in the tumor and can thus provide valuable clinical information for characterizing the tumors. (orig.) [German] Die Eignung dynamischer Parameter des Zweikompartimentemodells zur Erkennung von Prostatakarzinomen und deren Korrelation mit der Tumormikrogefaessdichte wurden evaluiert. 43 Patienten mit bioptisch gesichertem Prostatakarzinom wurden untersucht, 28 mit 1,0 T- (Turbo-FLASH-) und 15 bei 1,5-T-MRT (FLASH) unter Infusion von 0,1 mmol/kg Gd-DTPA. Signal-Zeit-Kurven wurden nach einem offenen Zweikompartimentemodell in Amplitude sowie Austauschratenkonstante (k{sub ep}) parametrisiert. An resezierten Prostatakarzinomen wurde die Mikrogefaessdichte bestimmt.Ergebnisse Die Mikrogefaessdichte in den Tumoren war signifikant hoeher als im angrenzenden gesunden Prostatagewebe und korrelierte bei beiden Sequenzen mit k{sub ep

  3. [Cerebral MRT in neurofibromatosis: gliosis versus neoplasia?].

    Science.gov (United States)

    Mautner, V F; Pressler, M; Fünsterer, C; Schneider, E

    1989-08-01

    15 patients aged 1-39 years with documented neurofibromatosis had MR examinations of the cerebrum within the scope of a basic diagnosis and therapy programme. Clinical examination did not lead to pathologic findings for 7 of the patients; 3 patients suffered from general developmental disabilities. A neurologico-psychiatric examination showed pathological findings in 5 patients. Signal-intense foci in proton density and T2-weighted MR images were found in the globus pallidus, thalamus, hippocampus, cerebellum and midbrain. In 2 patients, these foci could be found as well in T1-weighted images. Differentiation between gliosis areas and low grade astrocytomas was not possible in MR.

  4. MRT fuel element inspection at Dounreay

    Energy Technology Data Exchange (ETDEWEB)

    Gibson, J.

    1997-08-01

    To ensure that their production and inspection processes are performed in an acceptable manner, ie. auditable and traceable, the MTR Fuel Element Fabrication Plant at Dounreay operates to a documented quality system. This quality system, together with the fuel element manufacturing and inspection operations, has been independently certified to ISO9002-1987, EN29002-1987 and BS5750:Pt2:1987 by Lloyd`s Register Quality Assurance Limited (LRQA). This certification also provides dual accreditation to the relevant German, Dutch and Australian certification bodies. This paper briefly describes the quality system, together with the various inspection stages involved in the manufacture of MTR fuel elements at Dounreay.

  5. MRT des Pankreas: Radiologisch-pathologische Korrelation

    NARCIS (Netherlands)

    Helmberger, T.; Holzknecht, N.; Gauger, J.; Beuers, U.; Reiser, M.

    1996-01-01

    The typical MRI features of the most common pancreatic diseases, such as pancreatitis and adenocarcinoma of the pancreas, have been established. However, even in these common pancreatic disorders, MRI correlation with the underlying pathology is limited for clinical reasons. We emphasize

  6. Prediction of the pharmacological effect of octreotide in acromegaly by means of {sup 111}In-pentetreotide scintigraphy and calculation of a pituitary uptake index; Praediktion der pharmakologischen Wirkung von Octreotid bei Akromegalie mittels {sup 111}In-Pentetreotid-Szintigraphie und Berechnung eines hypophysaeren Uptake-Index

    Energy Technology Data Exchange (ETDEWEB)

    Goerges, R. [Mainz Univ. (Germany). Klinik und Poliklinik fuer Nuklearmedizin; Cordes, U. [Arbeitsgemeinschaft Niedergelassener Endokrinologen, Mainz/Darmstadt (Germany); Engelbach, M. [Mainz Univ. (Germany). III. Medizinische Klinik und Poliklinik; Bartelt, K.M. [Arbeitsgemeinschaft Niedergelassener Endokrinologen, Mainz/Darmstadt (Germany); Haberern, G. [Mainz Univ. (Germany). Klinik und Poliklinik fuer Nuklearmedizin; Hey, O. [Mainz Univ. (Germany). Neurochirurgische Klinik und Poliklinik; Beyer, J. [Mainz Univ. (Germany). III. Medizinische Klinik und Poliklinik; Bockisch, A. [Mainz Univ. (Germany). Klinik und Poliklinik fuer Nuklearmedizin

    1997-06-01

    Aim: The aim of our prospective study was to optimize the determination of the pituitary somatostatin receptor status by means of 111-In-pentetreotide scintigraphy and to compare it intraindividually with the pharmacological effect of octreotide in active acromegaly. Methods: In n=22 patients with growth hormone (GH) secreting pituitary adenoma, 111-In-penetreotide scintigraphy was performed, and the specific radionuclide accumulation in the pituitary area (evaluation visually as well as semiquantitatively by means of ROI technique and calculation of various uptake indices) was correlated with the acute drop of GH after administration of 100 {mu}g octreotide s.c. (octreotide acute test). Results: The uptake index we propose (cts/pixel-ratio circular pituitary ROI: Irregular cerebrum ROI after background correction in the sagittal SPECT slice with maximum pituitary uptake 24 h p.i.) correlates best with the pharmacological effect (acute decrease of GH levels) of octreotide; its upper normal limit amounts of 3.5. Conclusion: As often the normal pituitary gland can be visualized scintigraphically, the purely visual differentiation between a normal and pathological receptor status sometimes is equivocal. A pituitary uptake index, calculated by means of a standardized ROI technique, facilitates this discrimination and so contributes to select possible responders for a treatment with octreotide. (orig.) [Deutsch] Ziel: Ziel unserer prospektiven Studie war die optimierte Bestimmung des hypophysaeren Somatostatin-Rezeptorstatus in der 111-In-Pentetreotid-Szintigraphie und der intraindividuelle Vergleich mit dem pharmakologischen Effekt von Octreotid bei florider Akromegalie. Methoden: Bei n=22 Patienten mit Wachstumshormon-(GH)-sezernierendem Hypophysenadenom wurde eine 111-In-Pentetreotid-Szintigraphie durchgefuehrt und die spezifische Nuklidakkumulation in der Hypophysenregion (Auswertung sowohl visuell als auch semiquantitativ mittels ROI-Technik und Berechnung

  7. MR imaging in chronic epicondylitis humeri radialis at 1.0 T: is Gd-DTPA administration useful?; MRT bei chronischer Epicondylitis humeri radialis an einem 1,0 T-Geraet - Kontrastmittelgabe notwendig?

    Energy Technology Data Exchange (ETDEWEB)

    Herber, S.; Kalden, P.; Kreitner, K.-F.; Thelen, M. [Tuebingen Univ. (Germany). Klinik und Poliklinik fuer Radiologie; Riedel, C.; Rompe, J.D. [Klinik und Poliklinik fuer Orthopaedie Johannes-Gutenberg-Univ. Mainz (Germany)

    2001-05-01

    eine Flash 2D-Sequenz. Au paragraph erdem wurde eine T{sub 1}-gewichtete, fettsupprimierte SE-Sequenz vor und nach i.v. KM-Gabe angefertigt. Ergebnisse: In 39/42 Faellen wurden pathologische Veraenderungen der Extensorensehnen beobachtet. Eine pathologische Verdickung oder eine Ruptur respektive Partialruptur des Lig. collaterale radiale zeigte sich in 15/42 Faellen, ein Knochenmarkoedem am lateralen Epicondylus wiesen 6 Patienten und einen Gelenkerguss 18/42 auf. Nach KM-Gabe zeigte sich in der T{sub 1}-gewichteten SE-Sequenz in 29/42 Faellen ein durchschnittlicher Anstieg des Signal-zu-Rausch-Verhaeltnisses um den Faktor 1,5. Zusatzinformationen durch Kontrastmittelgabe wurden im Vergleich zur Nativdiagnostik nicht gewonnen. Schlussfolgerung: Im Rahmen der MRT-Bildgebung bei chronischer Epicondylitis kann auf die i.v. Gabe von Gadolinium-DTPA bei fehlendem diagnostischen Zugewinn verzichtet werden. (orig.)

  8. Engineering geological and hydrogeological invstigations for storage of medium and low-activity nuclear waste at Cernavoda, Romania. Soil stabilisation using the CONSOLID system; Ingenieurgeologische und hydrogeologische Untersuchungen zur Lagerung mittel- und schwachradioaktiver Abfaelle in Cernavoda Rumaenien. Baugrundstabilisierung mit dem CONSOLID-System

    Energy Technology Data Exchange (ETDEWEB)

    Giurgea, V.; Merkler, G.P.; Hoetzl, H.; Hannich, D. [Karlsruhe Univ. (T.H.) (Germany). Lehrstuhl fuer Angewandte Geologie

    1998-12-31

    In Cernavoda/Romania investigations and planning from a low and middle radioactive waste disposal site have been carried out. A multitude of hydrogeological, geological, engineering geological criteria`s and constructional security measures were examined with respect to the strict regulations for such a waste site. This studies and measures are shortly analyzed and discussed in this paper. In accordance with the selection criteria for such a hazardous waste site, several laboratory and `in situ` tests, soil-mechanic studies, numerical modeling and foundation tests for soil stabilization with the CONSOLID-System are presented. (orig.) [Deutsch] Zur Einhaltung der strengen Vorgaben, die bei einem Deponiestandort fuer mittel- und schwachradioaktive Abfaelle gestellt werden, sind in Cernavoda/Rumaenien eine Vielzahl von hydrogeologischen und ingenieurgeologischen Untersuchungen sowie bautechnischen Sicherungsmassnahmen vorgesehen, die im Rahmen dieser Publikation kurz analysiert und diskutiert werden. Im Zusammenhang mit den geologischen und hydrogeologischen Auswahlkriterien des Standortes werden eine Reihe von Labor- und `in situ` Untersuchungen, Modellrechnungen sowie Baugrundstabilisierungsmassnahmen mit dem CONSOLID-System vorgestellt. (orig.)

  9. Clinical value of FDG hybrid-PET in staging and restaging of malignant lymphoma. Compared with conventional diagnostic methods; Klinische Wertigkeit der Befunde von FDG-PET mittels Koinzidenz-Gammakamera beim Staging und Restaging maligner Lymphome. Ein Vergleich zu konventioneller Diagnostik

    Energy Technology Data Exchange (ETDEWEB)

    Pichler, R.; Maschek, W.; Hatzl-Griesenhofer, M.; Huber, H. [Allgemeines Krankenhaus Linz (Austria). Inst. fuer Nuklearmedizin; Wimmer, G.; Wahl, G.; Fridrik, M. [Allgemeines Krankenhaus Linz (Austria). I. Medizinische Abt.

    2000-09-01

    Aim of the present retrospective study was to validate the clinical value of F-18-FDG PET imaging in lymphoma patients with a dual head camera modified for coincidence detection. Staging before and after oncological treatment was compared with a conservative diagnostic approach. Methods: 48 patients (28 non-Hodgkin lymphoma, 20 Hodgkin's disease) received FDG-Hybrid-PET scans. Pretherapeutic staging was realized in 28 patients, 9 of them had control studies after they had completed therapy. Totally 29 persons were examined for posttherapeutic restaging. Computed tomography imaging and lymph node sonography was performed in all cases. Results were validated by clinical follow-up, in three cases a recidive was proven by biopsy. Results: CT and ultrasound detected 77 lesions in 28 patients compared with 100 visualized by PET, but this difference in pretherapeutic staging did not reach significance at p>0.05 by Fisher's t-test. Hybrid-PET obtained a sensitivity of 93%, a specifity of 79%, a positive of 82% and a negative predictive value of 92% for detection of residual disease. The values for CT+US were 87%, 64%, 72% and 88% respectively. Conclusion: FDG Hybrid-PET is as or even more accurate than standard morphologic diagnostic methods for prestaging in malignant lymphoma. Additionally, there is a substancial benefit for therapy monitoring of residual disease using coincidence detection PET with a 3/4-inch crystal gamma camera. (orig.) [German] Ziel der vorliegenden retrospektiven Studie war die Validierung der klinischen Wertigkeit von F-18-FDG-PET mittels Doppelkopf-Koinzidenz-Gammakamera bei Lymphompatienten. Die Ergebnisse von prae- und post-therapeutischem Staging wurden mit dem konservativ bildgebender Verfahren verglichen. Methoden: 48 Patienten (28 NHL, 20 Morbus Hodgkin) erhielten FDG-DK-PET-Untersuchungen. Ein praetherapeutisches Staging wurde bei 28 Patienten durchgefuehrt, 9 von diesen hatten weitere Kontrollstudien nach abgeschlossenem

  10. MRT of abdomen and pelvis. 2. tot. rev. and enl. ed.; MRT von Abdomen und Becken

    Energy Technology Data Exchange (ETDEWEB)

    Hamm, B.; Krestin, G.P. (eds.); Laniado, M.; Nicolas, V.; Taupitz, M.

    2007-07-01

    The book offers maximum expert knowledge from an experienced team of authors, first-class reference image material, clear guidelines for indications and actions also in comparison with other techniques, and a detailed presentation of examination sequences with table protocols. There are clear schematic drawings, guidelines, key findings and tables for differential diagnosis, and a list of possible misinterpretations. The authors present contributions on MR angiography and examination of infants and take account of all modern trends and indications. The book facilitates introduction to the subject, reading-up, and quick reference. It provides practical support at the workplace and is written in a user-friendly manner. There is a new chapter ''rectum'', and the book contains more than 1000 illustrations. (orig.)

  11. CT and MRT in mediastinal and hilar masses. CT und MRT bei mediastinalen und hilaeren Raumforderungen

    Energy Technology Data Exchange (ETDEWEB)

    Prayer, L.; Kramer, J.; Stiglbauer, R.; Wimberger, D.; Imhof, H. (Vienna Univ. (Austria). Klinik fuer Radiodiagnostik Ludwig-Boltzmann-Institut fuer Radiologisch-Physikalische Tumordiagnostik, Vienna (Austria)); Metz, V. (Vienna Univ. (Austria). 2. Chirurgische Klinik)

    1990-11-01

    Thirty-eight patients with mediastinal and/or hilar masses were imaged by computed tomography (CT) and magnetic resonance imaging (MRI). Results were analyzed retrospectively regarding the ability to demonstrate the masses, their number, size, definition, location and tissue characteristics. CT and MRI showed equivalent results in 32 cases; additional information was obtained in two patients by CT, in four patients by MRI. In view of the specific advantages and limitations of both CT and MRI we believed that in patients with mediastinal and/or hilar masses, contrast enhanced CT remains the procedure of choice after performing plain chest radiographs; in certain cases MRI will prove useful for further evaluation. (orig.).

  12. Fetal magnetic resonance imaging of thoracic and abdominal malformations; Fetale Magnetresonanztomographie thorakaler und abdomineller Malformationen

    Energy Technology Data Exchange (ETDEWEB)

    Woitek, R.; Asenbaum, U.; Furtner, J.; Prayer, D. [Medizinische Universitaet Wien, Abteilung fuer Neuroradiologie und Muskuloskelettale Radiologie, Universitaetsklinik fuer Radiodiagnostik, Wien (Austria); Brugger, P.C. [Medizinische Universitaet Wien, Zentrum fuer Anatomie und Zellbiologie, Wien (Austria)

    2013-02-15

    Diagnosis and differential diagnosis of fetal thoracic and abdominal malformations. Ultrasound and magnetic resonance imaging (MRI). In cases of suspected pathologies based on fetal ultrasound MRI can be used for more detailed examinations and can be of assistance in the differential diagnostic process. Improved imaging of anatomical structures and of the composition of different tissues by the use of different MRI sequences. Fetal MRI has become a part of clinical routine in thoracic and abdominal malformations and is the basis for scientific research in this field. In cases of thoracic or abdominal malformations fetal MRI provides important information additional to ultrasound to improve diagnostic accuracy, prognostic evaluation and surgical planning. (orig.) [German] Diagnose und Differenzialdiagnose fetaler thorakaler und abdomineller Malformationen. Ultraschall, MRT. MRT zur weiteren Abklaerung und genaueren Differenzierung bei vielen im Ultraschall gestellten Verdachtsdiagnosen. Verbesserte anatomische Darstellung mittels MRT und Darstellung unterschiedlicher Gewebezusammensetzung mittels verschiedener MR-Sequenzen. Die fetale MRT ist bei der angegebenen Fragestellung in die klinische Routine eingegangen und liefert weiterhin die Basis fuer wissenschaftliche Untersuchungen in diesem Bereich. Die fetale MRT liefert beim Vorliegen thorakaler oder abdomineller Malformationen komplementaer zum Ultraschall wichtige Zusatzinformationen, um die diagnostische Genauigkeit zu erhoehen, die Prognoseabschaetzung zu verbessern und ggf. eine bessere chirurgische Planung zu ermoeglichen. (orig.)

  13. Cortical blindness after intoxication with heroin; Kortikale Blindheit nach Heroinintoxikation

    Energy Technology Data Exchange (ETDEWEB)

    Braendli, M. [Institut fuer Diagnostische Radiologie, Universitaetskliniken, Kantonspital Basel (Switzerland); Otte, A.; Mueller-Brand, J. [Institut fuer Nuklearmedizin, Universitaetskliniken, Kantonspital Basel (Switzerland)

    2000-07-01

    For the case reported, both morphological and functional diagnostic examination methods were applied, such as MRI and CT, or SPECT using ECD as a tracer. The bilateral, occipital lesion finally could be detected with the SPECT examinations, and SPECT findings were clearly better than MRI findings, whereas even restrospective analysis of the CT images failed to show the lesion. Thus the functional imaging method in this case of a discrete bilateral occipital lesion was the most sentitive method. (orig./CB) [German] In unserem Fallbeispiel wurden sowohl morphologische (MRT, CT) als auch funktionelle Bildgebung (SPECT unter Verwendung von ECD als Tracer) ad extensum zur Diagnosefindung verwendet. Die bilaterale okzipitale Defektbildung konnte schliesslich mittels SPECT-Untersuchung deutlich besser dargestellt werden als mittels MRT. In der CT gelangte der Befund - auch bei retrospektiver Betrachtung - ueberhaupt nicht zur Darstellung. Damit war die funktionelle Bildgebung im Falle dieser diskreten bilateralen okzipitalen Defektbildung die sensitivste Methode. (orig.)

  14. Urämische Kardiomyopathie und der Einfluss der Hämodialyse

    OpenAIRE

    Valina, Ulrike Katrin

    2011-01-01

    ZIEL: Analyse von Risikofaktoren und Entstehungsmechanismen der urämischen Kardiomyopathie bei Hämodialysepatienten und Vergleich von Diagnostiken zur frühen Detektion kardialer Funktionstörungen zur Optimierung der Therapie bei terminaler Niereninsuffizienz und Senkung der hohen Mortalitätsrate. METHODEN: Einschluss von 32 Hämodialysepatienten. Messungen mittels Blutentnahme (Entzündungs-, Atherosklerose-, Anämieparameter, EPO, PTH und RAAS) und MRT (Herzfunktion, Herzmorphologie und Her...

  15. Das Gesprächsführungspraktikum im 2. Studienjahr des Modellstudiengangs HannibaL: Eine Evaluation mittels Selbsteinschätzungen der Studierenden [The communication skills course for second year medical students at Hannover Medical School: An evaluation study based on students' self-assessments

    Directory of Open Access Journals (Sweden)

    von Lengerke, Thomas

    2011-11-01

    . Regarding methods, the deployed simulated patients (2-4 per 10-student-course group in 3 of the 7 course sessions, respectively were rated the most helpful. The present evaluation calls for both further development of the doctor-patient communication curriculum at the MHH and joint activities across medical schools, which are discussed at the end of the paper. [german] Im MHH-Modellstudiengang HannibaL werden Gesprächsführungskompetenzen für Anamneseerhebung und Diagnosemitteilung durch eine Objective Structured Clinical Examination (OSCE geprüft, die Teil der dem Ersten Abschnitt der Ärztlichen Prüfung äquivalenten Prüfungen sind. Das vorbereitende Gesprächsführungspraktikum im 2. Studienjahr wurde 2009/10 evaluiert.Mittels lernzielspezifischer Fragebogen wurden der Lernbedarf erhoben, Vorher-Nachher-Vergleiche der selbsteingeschätzten Kompetenzen durchgeführt und zentrale Lehrmethoden bewertet (5-Punkt-Likertskalen, „5“=hohe Ausprägung. Zu T0 (Beginn des Praktikums nahmen 267 Studierende teil (Teilnahmerate: 93,7%, von denen 180 den T1-Fragebogen beim letzten Praktikumstermin ausfüllten (67,4%. Es wurden Varianzanalysen mit Messwiederholungsfaktor und T-Tests für verbundene Stichproben durchgeführt. Die höchsten Lernbedarfe zeigten sich bei den „to show how“-Items zu Anamneseerhebung und Diagnosemitteilung (M=4,4. Die T1-T0-Vergleiche zeigten die größten Verbesserungen bei den anamnesespezifischen Items („to know how“: Mittelwertsdifferenz=+1,7, „to show how“:+1,8, p<.0001 wie bei allen Tests und beim „to know how“-Item zur Diagnosemitteilung (+1,6, gefolgt von der Umsetzung einer Diagnosemitteilung (+1,4, partizipativer Entscheidungsfindung (+1,2, der Einschätzung eigener Stärken/Schwächen (+1,0 und dem sicheren Zugehen auf neue Patienten (+0,7. Studierende mit T0-Werten von „1“ oder „2“ auf den jeweiligen Skalen verbesserten sich über alle Items im Mittel um 2,2 Punkte, solche mit „3“ um 1,1, und mit „4“ oder

  16. Investigations on avoidance of hot cracks during laser welding of austenitic Cr-Ni steels and nickel-based alloys using temperature field tailoring. Final report; Untersuchungen zur Vermeidung von Heissrissen beim Laserstrahlschweissen von austenitischen Cr-Ni-Staehlen und Nickelbasislegierungen mittels Temperaturfeld-Tailoring. Schlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-08-08

    . Zweitens wird bei rotationssymmetrischen Bauteilen, die mittels einer Axial-Rundnaht zu verschweissen sind, mit einem relativ einfachen Temperaturfeld, das durch Erwaermung des innen liegenden Fuegepartners vor und waehrend des Schweissens aufgebaut wird, ein Spannungsfeld erzeugt, das die Bildung von Heissrissen verhindert. Schliesslich konnte drittens ein heissrissfreies Laserstrahlschweissen des Stahls 1.4305 und der Nickelbasislegierung Udimet 720 bereits ohne den Einsatz zusaetzlicher Temperaturfelder erreicht werden. Die Grenzen der Einsetzbarkeit des Verfahrens bei Cr-Ni-Staehlen werden dann erreicht, wenn Quer-Heissrisse oder parallel zur Blechoberflaeche liegende Heissrisse entstehen. Die zur Vermeidung dieser Risse noetigen Druckspannungen in den Richtungen parallel zur Schweissnaht bzw. senkrecht zur Blechoberflaeche koennen mittels induktiver Erwaermung von der Blechoberseite aus nicht in der erforderlichen Groesse erzeugt werden. Ebenso stoesst das Verfahren an seine Grenzen, wenn Wiederaufschmelzungsrisse auftreten, was beim hier verwendeten Stahl 1.4435 der Fall war. Die Spannungen, die zur Verhinderung einer Rissoeffnung an den Korngrenzen der Waermeeinflusszone erforderlich waeren, konnten durch Temperaturfeld-Tailoring nicht erreicht werden. Die Moeglichkeit des heissrissfreien Schweissens des Stahls 1.4305 auch ohne Temperaturfeld-Tailoring ergibt sich hauptsaechlich aus dem primaer ferritischen Erstarrungsmodus des Stahls in der vorliegenden Legierungszusammensetzung. Ein industrieller Einsatz des Laserstrahlschweissens fuer diesen oft als nicht schweissbar klassifizierten Stahl erscheint moeglich, wenn bei der Legierungszusammensetzung auf niedrige Anteile der Austenitbildner Nickel, Kohlenstoff und Stickstoff Wert gelegt wird und damit eine stabil primaer ferritische Erstarrung erreicht wird. Fuer diesen Fall kommt es nicht zur Schwefelanreicherung an den Korngrenzen, wodurch die Bildung niedrigschmelzender Phasen und damit die Heissrissentstehung

  17. Focal lesions in whole-body MRI in multiple myeloma. Quantification of tumor mass and correlation with disease-related parameters and prognosis; Fokale Laesionen in der Ganzkoerper-MRT beim multiplen Myelom. Quantifizierung der Tumorlast und Korrelation mit krankheitstypischen Parametern und Prognose

    Energy Technology Data Exchange (ETDEWEB)

    Brandelik, S.C.; Kauczor, H.U. [Universitaetsklinikum Heidelberg, Diagnostische und Interventionelle Radiologie, Heidelberg (Germany); Krzykalla, J.; Hielscher, T. [Deutsches Krebsforschungszentrum (dkfz), Biostatistik, Heidelberg (Germany); Hillengass, J. [Universitaetsklinikum Heidelberg, Haematologie und Onkologie, Heidelberg (Germany); Kloth, J.K. [Radiologie Loebau, Loebau (Germany); Weber, M.A. [Universitaetsklinikum Heidelberg, Diagnostische und Interventionelle Radiologie, Heidelberg (Germany); Universitaetsmedizin Rostock, Diagnostische und Interventionelle Radiologie, Rostock (Germany)

    2018-01-15

    In this study, we evaluated methods of quantification of tumor mass in whole-body MRI (wb-MRI) in multiple myeloma and correlated these with disease-related parameters in serum and bone marrow. We retrospectively evaluated wb-MRIs of 52 patients with focal infiltration pattern and a total of 700 focal lesions (subsequently called lesions). We determined the longest diameter (LD), the segmented volume (SV), and the morphology (spherical or non-spherical). We correlated total number/volume of the lesions with clinical parameters and prognosis and furthermore LD with SV. After that we analyzed the agreement of SV and estimated volume (EV) using the volume formula of a sphere based on LD. Results showed no significant correlations of total number/volume with prognosis or clinical parameters. The latter were situated predominantly in the normal range. Furthermore, 10% of lesions were spherical. SV and LD correlated significantly in single lesions and on patient level. SV was in lesions <6 cm{sup 3} systematically larger and in lesions ≥6 cm{sup 3} smaller than EV. In 95%, we found in small lesions a deviation of EV versus SV from +0.9 cm{sup 3} to -4.6 cm{sup 3} and in large lesions from +160 cm{sup 3} to -111 cm{sup 3} (EV-SV). Quantification of tumor mass in the focal infiltration pattern is performed more accurately by volumetry than LD due to the predominant existence of non-spherical lesions. The patient cohort with clinical parameters predominantly in the normal range is distributed to ISS stage I and partly pretreated, a fact that makes interpretation of absent correlations more difficult. Consider also a variation in activity of lesions and a diffuse infiltration not detectable by MRI. (orig.) [German] In dieser Studie wurden Methoden der Tumorlastquantifizierung in der Ganzkoerper-Magnetresonanztomographie (GK-MRT) beim Multiplen Myelom untersucht und mit krankheitstypischen Parametern in Serum und Knochenmark korreliert. Die GK-MRT von 52 Patienten mit

  18. Value of different MR techniques in diagnosis of degenerative disorders of the hyaline cartilage - in vitro study on 50 joint specimens of the knee with 1.5 T; Vergleich von verschiedenen MRT-Techniken in der Diagnose von degenerativen Knorpelerkrankungen - in-vitro-Studie an 50 Gelenkpraeparaten des Knies bei 1,5 T

    Energy Technology Data Exchange (ETDEWEB)

    Bachmann, G. [Klinikum der Univ. Giessen (Germany). Abt. Diagnostische Radiologie; Heinrichs, C. [Klinikum der Univ. Giessen (Germany). Inst. fuer Pathologie; Juergensen, I. [Klinikum der Univ. Giessen (Germany). Orthopaedische Klinik; Rominger, M. [Klinikum der Univ. Giessen (Germany). Abt. Diagnostische Radiologie; Scheiter, A. [Klinikum der Univ. Giessen (Germany). Abt. Diagnostische Radiologie; Rau, W.S. [Klinikum der Univ. Giessen (Germany). Abt. Diagnostische Radiologie

    1997-05-01

    Purpose: An experimental study was performed on joint specimens of the knee to assess the advantages and disadvantages of 14 generally available sequences in cartilage imaging. Methods: Each of the 50 surgically exposed cadaveric joints of the knee was examined by the following sequences: T{sub 1}, proton- and T{sub 2} weighted spin echo(SE) sequences, proton- and T{sub 2} weighted Turbo-SE, T{sub 1} weighted SE with fat suppression, MTC combined with T{sub 1}-weighted SE and T{sub 2} weighted FLASH-2 D, STIR, FISP-3 D, FLASH-3 D (with fat suppression), and MR arthrography. We assessed the image quality by a scale, signal to noise-ratio of cartilage and joint fluid, and the accuracy in detection of cartilage lesions. Pathology and arthroscopy were reference methods to MRI, and demonstrated grade 1-4 lesions on 186 of 300 joint facettes. Results: Advanced stages of cartilage lesions (65 grade 3 and 4 lesions) were detected by standard SE sequences in 67-94%. Application of volume techniques (FISP-3 D, FLASH-3 D), high definition matrix (512 pixel), MTC with FLASH-2 D and MR-arthrography improved the sensitivity up to 82-100%. Superficial lesions (65 grade 2 lesions) were demonstrated in 3-38%, and on MR arthrography in 45%. Structural changes (56 Grade 1 lesions) were recorded on MRI in only 10%. Conclusions: With regard to standard SE sequences, the detectability of cartilage lesions can be improved by techniques that use 512 matrices, selective cartilage imaging, and volume acquisition. (orig.) [Deutsch] Ziel: In einer experimentellen Studie an Gelenkpraeparaten des Knies wurden die Vor- und Nachteile von 14 allgemein verfuegbaren MRT-Sequenzen in der Knorpeldiagnostik dargestellt. Methode: 50 chirurgisch exstirpierte Kniegelenkpraeparate wurden nacheinander mit folgenden Techniken untersucht: Klassische Spin-Echo(SE)-Sequenz in T{sub 1}-, Protonen- und T{sub 2}-Wichtung, Turbo-SE in Protonen- und T{sub 2}-Wichtung, Fettsuppression mit T{sub 1}-gew. SE, MTC in

  19. Treatment of malignant biliary occlusion by means of transhepatic percutaneous biliary drainage with insertion of metal stents - results of an 8-year follow-up and analysis of the prognostic parameters; Behandlung der malignen Gallenwegsstenose mittels perkutaner transhepatischer Metallendoprothesenimplantation: 8 Jahres-Ergebnisse und Analyse prognostischer Faktoren

    Energy Technology Data Exchange (ETDEWEB)

    Alfke, H.; Alfke, B.; Froelich, J.J.; Klose, K.J.; Wagner, H.J. [Klinik fuer Strahlendiagnostik Philipps Univ. Marburg (Germany)

    2003-08-01

    praediktive Faktoren fuer Ueberleben und Offenheitsraten zu detektieren. Methode: In einer retrolektiven Analyse wurden 130 Patienten evaluiert. Nachsorgedaten wurden anhand der Krankenakten und eines Telephoninterviews erhoben. Verfahrensassoziierte Daten waren prospektiv in einer Datenbank erhoben worden. Univariate und multivariate Vergleiche der Ueberlebens- und Offenheitsraten wurden mittels Kaplan-Meier-Analyse mit Log-Rank-Test fuer verschiedene Tumorentitaeten durchgefuehrt. Praediktive Faktoren fuer das Ueberleben und die 30-Tages-Mortalitaet wurden durch eine schrittweise logistische Regression evaluiert. Ergebnisse: Ursachen fuer die maligne Gallenwegsobstruktion waren Cholangiokarzinome (n=50), Pankreaskarzinome (29), Lebermetastasen (27), Gallenblasenkarzinome (20) und andere (4). Die technische Erfolgsrate betrug 99%, die Komplikationsrate 27% und die 30-Tages-Mortalitaet 11%. Die primaere Stentoffenheitsrate (406 Tage, Median 207) unterschied sich nicht signifikant fuer die verschiedenen Tumorentitaeten. Die Ueberlebensrate war fuer Patienten mit Cholangiokarzinomen in der univariaten Analyse signifikant besser (p=0,03 Log-Rank-Test). Die multiple Regressionsanalyse detektierte keine praediktiven Faktoren fuer das Ueberleben und die 30-Tages-Mortalitaet. Schlussfolgerungen: Die perkutane transhepatische Metallendoprothesenimplantation bietet den Patienten eine gute kurz- und langfristige palliative Therapie des Ikterus an. Obwohl die Ueberlebenszeit fuer Patienten mit Cholangiokarzinomen signifikant laenger ist, fehlen klare praediktive Faktoren fuer ein laengeres Ueberleben und eine erhoehte 30-Tages-Mortalitaet. (orig.)

  20. Decarbonization by means of hydrogen; Dekarbonisierung mittels Wasserstoff

    Energy Technology Data Exchange (ETDEWEB)

    Kreutzer, Ulrich [Siemens AG, Muenchen (Germany). Research in Energy and Electronics, Corporate Technology

    2018-01-15

    Hydrogen electrolysis plays a crucial role in reducing CO{sub 2} emissions. With the help of regeneratively generated electricity, it converts water into its constituents hydrogen and oxygen without producing carbon dioxide. Experts are working on the still young PEM technology, which is particularly efficient and environmentally friendly. The holistic optimization of the plant plays an important role. [German] Wasserstoffelektrolyse spielt eine entscheidende Rolle, um CO{sub 2}-Emissionen einzudaemmen. Mit Hilfe regenerativ erzeugtem Strom wandelt sie Wasser in seine Bestandteile Wasserstoff und Sauerstoff um, ohne dass dabei Kohlenstoffdioxid entsteht. Experten arbeiten an der noch jungen PEM-Technologie, die besonders effizient und umweltvertraeglich ist. Eine wichtige Bedeutung hat dabei die ganzheitliche Optimierung der Anlage.

  1. Sliding bearing diagnosis with magnetic field measuring; Gleitlagerdiagnose mittels Magnetfeldmessungen

    Energy Technology Data Exchange (ETDEWEB)

    Bittner, H. [HWTS Zittau (Germany). Fachgebiet Instandhaltung/Technische Diagnostik; Kluth, T. [HWTS Zittau (Germany). Fachgebiet Instandhaltung/Technische Diagnostik

    1995-09-01

    Account of their properties sliding bearings are in high demanded and important aggregats. The destruction of a bearing will be almost followed by the destruction of the aggregate. Various methods are existing for sliding bearing diagnosis. This methods often not permit the condition recognition. A new electromagnetical method will be developed. This method permits the condition recognition during working time of the aggregate. It also permits the recognition of wear. The method bases on a measuring of leak current over measuring the generated magnetic fields with Rogowski-coils. (orig.) [Deutsch] Gleitlager befinden sich wegen ihrer Eigenschaften in hoch beanspruchten und exponierten Aggregaten. Die Zerstoerung eines Gleitlagers fuehrt meist auch zur Zerstoerung des gefuehrten Aggregats. Zur Gleitlagerdiagnose existiert eine Reihe Verfahren. Ihnen wird ein elektromagnetisches Verfahren gegenuebergestellt. Damit koennen Gleitlagerzustaende waehrend des Aggregatebetriebs identifiziert werden. Das Verfahren erlaubt gleichermassen die Bestimmung des Lagerverschleisses. Es basiert auf der Ableitstrommessung, bei der sich ausbildende Magnetfelder durch Rogowskispulen ausgemessen werden. (orig.)

  2. Oberflaechenverbesserung im 3D-Druck mittels hoeherer Aufloesung

    OpenAIRE

    Ederer, Ingo

    2008-01-01

    Mit pulvergestützten 3D-Druckprozessen verbindet der Anwender bislang vor allem eine hohe Prozessgeschwindigkeiten bei mäßiger Genauigkeit und Oberflächenqualität. Dass das auch anders geht zeigt der vorliegende Artikel.

  3. Development and application of dynamic MR-imaging for evaluation of perfusion changes in rectal carcinoma during a course of radiotherapy in clinical use. Preliminary results; Entwicklung und Anwendung dynamischer MRT-Messungen zur Evaluierung von Perfusionsveraenderungen bei Rektumkarzinomen unter Bestrahlung in der klinischen Routine. Erste Ergebnisse

    Energy Technology Data Exchange (ETDEWEB)

    Vries, A. de; Griebel, J.; Gneiting, T.; Hoflehner, J.; Brandl, M.; Lukas, P. [Leopold-Franzens-Univ. Innsbruck (Austria). Universitaetsklinik fuer Strahlentherapie - Radioonkologie; Judmaier, W.; Kremser, C.; Schocke, M.; Aichner, F. [Leopold-Franzens-Univ. Innsbruck (Austria). Inst. fuer Magnetresonanztomographie; Peer, S.; Rettl, G. [Leopold-Franzens-Univ. Innsbruck (Austria). Universitaetsklinik fuer Radiodiagnostik I; Oefner, D. [Leopold-Franzens-Univ. Innsbruck (Austria). Universitaetsklinik fuer Chirurgie; Debbage, P. [Leopold-Franzens-Univ. Innsbruck (Austria). Inst. fuer Histologie und Embryologie

    1999-11-01

    koennte mittels der gewonnenen Daten eine individualisierte tumor- und perfusionsangepasste Therapieoptimierung bei kombinierter Radiochemotherapie durchgefuehrt werden. (orig.)

  4. Investigation of the local fracture toughness and the elastic-plastic fracture behavior of NiAl and tungsten by means of micro-cantilever tests; Untersuchung der lokalen Bruchzaehigkeit und des elastisch-plastischen Bruchverhaltens von NiAl und Wolfram mittels Mikrobiegebalkenversuchen

    Energy Technology Data Exchange (ETDEWEB)

    Ast, Johannes

    2016-07-01

    . This is linked to the thermally activated dislocation mobility which is more constrained in those samples. Investigations on plastically predeformed samples were performed in order to study the influence of the dislocation density on the fracture behavior. It was found that the fracture toughness was again not affected but that the predeformed samples failed at an earlier stage at lower J-integrals. This is due to the lower mobility of the dislocations emitted from the crack tip in consequence of the high amount of strain hardening and the higher flow stress in those samples. Experiments in ultrafine-grained tungsten revealed a fracture behavior which was more brittle than expected. A single grain at the crack front with its crystallographic orientation being prone to cleavage failure can decisively influence the fracture behavior at the micro scale. [German] Das Ziel dieser Arbeit war es, ein verbessertes Verstaendnis fuer die Groessenabhaengigkeit der Bruchzaehigkeit zu gewinnen. Hierfuer wurden mittels fokussierter Ionenstrahlen gekerbte Mikrobiegebalken in verschiedenen Groessen vom Submikrometerbereich bis hin zu einigen 10 μm in B2-NiAl und Wolfram praepariert. Diese beiden Materialien besitzen charakteristische Sproed-Duktil-Uebergange, die oberhalb der Raumtemperatur liegen. Dies erlaubte es, Bruchvorgaenge, welche von begrenzter plastischer Verformung um die Rissspitze begleitet werden, auf der Mikroskala zu untersuchen. Neue Methoden zur Beschreibung und Bestimmung des lokalen elastisch-plastischen Bruchverhaltens bzw. der Bruchzaehigkeit wurden hierfuer erarbeitet. Im Speziellen wurde das J-Integral-Konzept zur Ermittlung von Rissfortschritt ueber Steifigkeitsmessungen auf die Mikroskala uebertragen. Dies ermoeglichte eine praezise Analyse des fuer die Bruchzaehigkeit charakteristischen Uebergangs von Rissabstumpfung zu stabilem Rissfortschritt. Die Versuche an einkristallinem NiAl fuer die beiden untersuchten Risssysteme der harten und weichen Orientierung

  5. Dental magnetic resonance imaging; MRT der Zaehne und des Zahnhalteapparats

    Energy Technology Data Exchange (ETDEWEB)

    Hilgenfeld, Tim; Bendszus, Martin; Haehnel, Stefan [Universitaetsklinikum Heidelberg (Germany). Abt. fuer Neuroradiologie

    2016-03-15

    Growing distribution and utilization of digital volume tomography (DVT) extend the spectrum of clinical dental imaging. Additional diagnostic value, however, comes along with an increasing amount of radiation. In contrast, magnetic resonance imaging is a radiation free imaging technique. Furthermore, it offers a high soft tissue contrast. Morphological and numerical dental anomalies, differentiation of periapical lesions and exclusion of complications of dental diseases are field of applications for dental MRI. In addition, detection of caries and periodontal lesions and injury of inferior alveolar nerve are promising application areas in the future.

  6. MR imaging of muscle injuries; MRT von Muskelverletzungen

    Energy Technology Data Exchange (ETDEWEB)

    Woertler, Klaus [Technische Univ. Muenchen, Klinikum rechts der Isar (Germany). Inst. fuer Diagnostische und Interventionelle Radiologie

    2014-12-15

    Injuries to skeletal muscle are very common particularly in athletes. Besides ultrasound, MR imaging represents the most valuable imaging modality for diagnosis and grading of muscle lesions. This article reviews the examination technique and diagnostic criteria of acute and chronic lesions of skeletal muscle at MR imaging. In addition to the morphology of direct and indirect muscle injuries, MR findings in myositis ossificans and compartment syndrome are discussed as well.

  7. Effect of the positioning of the blades in MRT treatments

    International Nuclear Information System (INIS)

    Ortiz de Zarate Vivanco, R.; Perez Azorin, J. F.; Casquero Ocio, F.; Trueba Garayo, I.

    2013-01-01

    The attenuation of the beams of radiation that cross the treatment table is a verifiable fact that should be incorporated into the planning of the radiation treatments, especially in advanced techniques. (Author)

  8. Advances in fusion of PET, SPET, CT und MRT images

    International Nuclear Information System (INIS)

    Pietrzyk, U.

    2003-01-01

    Image fusion as part of the correlative analysis for medical images has gained ever more interest and the fact that combined systems for PET and CT are commercially available demonstrates the importance for medical diagnostics, therapy and research oriented applications. In this work the basics of image registration, its different strategies and the mathematical and physical background are described. A successful image registration is an essential prerequisite for the next steps, namely correlative medical image analysis. Means to verify image registration and the different modes for integrated display are presented and its usefulness is discussed. Possible limitations in applying image fusion in order to avoid misinterpretation will be pointed out. (orig.) [de

  9. MRI of the hip joint; MRT des Hueftgelenks

    Energy Technology Data Exchange (ETDEWEB)

    Czerny, C.; Noebauer-Huhmann, I.M.; Imhof, H. [Universitaetsklinik fuer Radiodiagnostik, Medizinische Univ. Wien (Austria)

    2005-12-01

    Magnetic resonance imaging (MRI) is performed to diagnose many pathologic conditions affecting the hip joint. Either conventional MRI (without contrast enhancement of the joint cavity) or MR arthrography is used to detect and most accurately differentiate hip joint pathologies. Conventional MRI is performed in cases of bone marrow edema, necrosis, arthrosis and especially the so-called ''activated arthrosis'', as well as in inflammatory and tumorous entities. MR arthography, which has only recently become available for use, is excellently suited for diagnosing lesions of the acetabular labrum, cartilage lesions, and free articular bodies. This article provides an overview about MRI characteristics and their accuracy of hip joint diseases and the impact on the therapeutic procedure. (orig.)

  10. Transmyocardial laser revascularization - first experiences of imaging in MRT

    International Nuclear Information System (INIS)

    Weber, C.; Maas, R.; Steiner, P.; Beese, M.; Hvalic, M.; Buecheler, E.; Stubbe, M.

    1998-01-01

    Purpose: Imaging of myocardial signal alteration and perfusion differences after transmyocardial laser revascularization (TMLR). Methods and Material: 5 patients suffering from coronary vessel disease underwent MRI (0.5 T) pre- and 4-7 d post-TMLR. T 1 -weighted spin echo sequences were acquired ECG-triggered native and after injection of gadolinium. Qualitative analysis was performed on both native and contrast-enhanced images. Myocardial signal alterations and wall changes were evaluated. Qualitative and quantitative analyses of contrast-enhanced images were performed with regard of post therapeutic perfusion differences. Analysis was based on contrast-to-noise (C/N) data obtained from operator defined 'regions of interest'. Results: Visualization of laser-induced channels was not possible. Native scans obtained before and after TMLR revealed no significant change with regard to the qualitative analysis. Both qualitative and quantitative analyses demonstrated a posttherapeutic increase of C/N in both the left ventricular myocardium (64.4 pre-TMLR; 89.1 post-TMLR; p=0.06) and the septum in the majority of cases. No significant difference between laser-treated left myocardium and untreated septum was observed (p>0.05). Discussion: Single myocardial laser channels could not be visualized with a 0.5-T MRI. However, visualization of increased myocardial contrast enhancement in laser-treated left ventricular myocardium was evident in the majority of cases on the basis of qualitative and quantitative analyses. Conclusions: The MRI technique used enabled a first, limited depiction of TMLR-induced myocardial changes. The clinical value and impact still have to be defined. (orig.) [de

  11. High Altitude Platforms Mobile Robotic Telesurgery (HAPsMRT)

    National Research Council Canada - National Science Library

    Broderick, Timothy J

    2006-01-01

    .... This demonstrated that a surgical robot could be deployed in an extreme environment and controlled by a surgeon who was remotely located from the robot using a wireless communication system (UAV...

  12. Whole body MRI in children; Ganzkoerper-MRT bei Kindern

    Energy Technology Data Exchange (ETDEWEB)

    Schaefer, Juergen F.; Tsiflikas, Ilias [Tuebingen Univ. (Germany). Bereich Kinderradiologie

    2014-09-15

    In pediatric patients whole body MRI has a relevant impact on both, diagnostic work-up and treatment. Using adapted sequence protocols comprehensive imaging without radiation exposure is possible avoiding additional examinations in many cases. Especially in bone marrow the differentiation between normal and abnormal finding can be difficult, therefore the knowledge of normal maturing of organs is important. Whole body diffusion weighted imaging particularly in neuroblastomas or sarcomas improves the low specificity of conventional MR-protocols. Technical prerequisites, examination protocol and strategies, image interpretation, indications and clinical relevance as well as advantages and disadvantages of whole body MRI will be discussed on the basis of application-oriented cases and the literature.

  13. Essentials of clinical MRI; Essentials der klinischen MRT

    Energy Technology Data Exchange (ETDEWEB)

    Attenberger, Ulrike I.; Schoenberg, Stefan O. (eds.) [Heidelberg Univ. Universitaetsmedizin Mannheim (Germany). Inst. fuer Klinische Radiologie und Nuklearmedizin; Runge, Val M. [Univ. of Texas Medical Branch (UTMB), Galveston, TX (United States). Dept. of Radiology; Morelli, John N. [Texas A and M Univ., Temple, TX (United States). Dept. of Radiology

    2011-07-01

    The text book on practical magnetic resonance imaging includes the following chapters: brain; cervical spine; thoracic spine; lumbar spine; head and neck; heart and thorax; mammary glands; abdomen and pelvis; musculoskeletal system; MRI contrast media; magnetic resonance angiography.

  14. Update in breast MRT. Standards and quality management; Update in der Mamma-MRT-Technik. Untersuchungsstandards und Qualitaetssicherung

    Energy Technology Data Exchange (ETDEWEB)

    Kurtz, Claudia [Kantonsspital Luzern, Lucerne (Switzerland). Inst. fuer Radiologie

    2013-06-15

    Meanwhile breast MRI has emerged to an important tool for breast diagnostics, with a broad spectrum of technical requirements and interpretation guidelines. The use of breast MRI is reasonable and helpful, provided that an appropriate application and optimal technical conditions are fulfilled, otherwise unnecessary follow-up examinations or biopsies might be initiated. This article gives an overview about planning and performing the examination, describes the physical background for optimal acquisition protocols, gives support for post-processing and image interpretation and also refers to possible misinterpretations. (orig.)

  15. Functional magnetic resonance imaging with ultra-high fields; Funktionelle Magnetresonanztomographie bei ultrahohen Feldern

    Energy Technology Data Exchange (ETDEWEB)

    Windischberger, C.; Schoepf, V.; Sladky, R.; Moser, E. [Medizinische Universitaet Wien, Exzellenzzentrum Hochfeld-MR, Wien (Austria); Medizinische Universitaet Wien, Zentrum fuer Medizinische Physik und Biomedizinische Technik, Wien (Austria); Fischmeister, F.P.S. [Medizinische Universitaet Wien, Exzellenzzentrum Hochfeld-MR, Wien (Austria); Universitaet Wien, Fakultaet fuer Psychologie, Wien (Austria)

    2010-02-15

    Functional magnetic resonance imaging (fMRI) is currently the primary method for non-invasive functional localization in the brain. With the emergence of MR systems with field strengths of 4 Tesla and above, neuronal activation may be studied with unprecedented accuracy. In this article we present different approaches to use the improved sensitivity and specificity for expanding current fMRT resolution limits in space and time based on several 7 Tesla studies. In addition to the challenges that arise with ultra-high magnetic fields possible solutions will be discussed. (orig.) [German] Die funktionelle Magnetresonanztomographie (fMRT) stellt zurzeit die wichtigste Methode zur nichtinvasiven Funktionslokalisation im Gehirn dar. Mit der Verfuegbarkeit von MRT-Geraeten mit Magnetfeldstaerken von 4 Tesla (T) und darueber ergeben sich neue Moeglichkeiten, mittels fMRT die neuronale Aktivitaet in bislang unerreichter Genauigkeit zu untersuchen. In diesem Artikel zeigen wir anhand mehrerer Studien bei 7 T, in wieweit die Zugewinne an Sensitivitaet und Spezifitaet verwendet werden koennen, um die bisherigen Grenzen der fMRT-Aufloesung in raeumlicher und zeitlicher Hinsicht auszuweiten. Die neuen Herausforderungen, die mit dem Schritt zu ultrahohen Magnetfeldern einhergehen, werden dabei ebenso diskutiert wie moegliche Ansaetze zu deren Loesung. (orig.)

  16. Neurogenic myopathies and imaging of muscle denervation; Neurogene Myopathien und Bildgebung der Muskeldenervation

    Energy Technology Data Exchange (ETDEWEB)

    Wolf, M. [Universitaetsklinikum Heidelberg, Abteilung fuer Neuroradiologie, Heidelberg (Germany); Wolf, C. [Reha-Zentrum Gernsbach, Neurologie, Gernsbach (Germany); Weber, M.A. [Universitaetsklinikum Heidelberg, Abteilung fuer Diagnostische und Interventionelle Radiologie, Heidelberg (Germany)

    2017-12-15

    , chronische Kompressionen sowie neurodegenerative, inflammatorische, metabolische und neoplastische Prozesse. Anamnese, klinisch-neurologische Untersuchung und elektrophysiologische Tests einschliesslich Elektromyographie (EMG) und Testung der Nervenleitgeschwindigkeit sind notwendig. Die EMG stellt den Goldstandard in der Diagnose von Muskeldenervierung dar. Ergaenzende bildgebende Methoden, vor allem die Magnetresonanztomographie (MRT) koennen teils sinnvolle Informationen liefern. Bei akuter und subakuter Denervierung weist die Muskulatur in der MRT Oedeme, ADC(''apparent diffusion coefficient'')-Erhoehung und gesteigerte Perfusion auf. Die mittels MRT nachweisbaren Veraenderungen denervierter Muskulatur sind relativ unspezifisch, erreichen aber eine vergleichbar hohe Sensitivitaet wie die EMG. Mittels dezidierter MR-Neurographie kann oft auch die ursaechliche Schaedigung des/der innervierenden Nerven visualisiert werden. Abgesehen von der mit der EMG vergleichbaren Sensitivitaet eignet sich die MRT zur Beurteilung von Muskeln, die einer Nadelelektromyographie nicht zugaenglich sind. Aufgrund ihres nichtinvasiven Charakters ist die MRT auch ideal fuer Verlaufsuntersuchungen. Oft ergaenzt die MRT die Diagnostik neurogener Myopathien sinnvoll. Ausmass und Verteilungsmuster der muskulaeren Veraenderungen lassen haeufig auf die Lokalisation der ursaechlichen Nervenschaedigung schliessen. Oft ermoeglichet die MRT eine korrekte Diagnosestellung oder zumindest eine Eingrenzung moeglicher Differenzialdiagnosen. (orig.)

  17. Imaging in syndrome complex diabetes mellitus. Current standards and future perspectives; Bildgebung im Syndromkomplex Diabetes mellitus. Stellenwert und Chancen

    Energy Technology Data Exchange (ETDEWEB)

    Hetterich, H.; Schafnitzel, A. [Klinikum der Ludwig-Maximilians-Universitaet, Campus Grosshadern, Institut fuer Klinische Radiologie, Muenchen (Germany); Bamberg, F. [Eberhard-Karls-Universitaet, Abteilung fuer Diagnostische und Interventionelle Radiologie, Tuebingen (Germany)

    2015-04-01

    Diabetes mellitus is a highly prevalent multisystemic disorder with numerous potential complications and substantial socioeconomic consequences. In many cases, the patient history, physical examination and laboratory tests are not sufficient for a comprehensive evaluation of complicating disorders. Imaging modalities, such as sonography, computed tomography (CT) and magnetic resonance imaging (MRI) are of major significance in the evaluation of complicating disorders of diabetes according to current guidelines. Examples include assessment of coronary artery disease, peripheral artery disease, stroke and diabetic foot syndrome. Technical developments allow a substantial reduction in radiation dose and scan time in CT and MRI, respectively and could therefore justify a broader application in this patient population. In the future CT and MRI could also be used for the early detection of diabetic complications. Furthermore, they could also be used for risk stratification, e.g. measurement of hepatic fat content and evaluation of atherosclerosis in whole body MRI. Prior to widespread application of advanced imaging techniques in this patient population, improved outcomes with respect to survival, quality of life and cost-effectiveness need to be demonstrated. Diagnostic imaging modalities for the evaluation of the syndrome complex of diabetic disorders should be used according to the current guidelines but the use is predicted to increase given the high potential in this population. (orig.) [German] Diabetes mellitus ist eine hochpraevalente Multisystemerkrankung mit zahlreichen Komplikationen und bedeutenden soziooekonomischen Konsequenzen. Die Folgeerkrankungen koennen oft nicht abschliessend mittels Anamnese, koerperlicher Untersuchung und laborchemischen Verfahren evaluiert werden. Radiologische Verfahren wie die Sonographie, Computertomographie (CT) und Magnetresonanztomographie (MRT) haben gemaess verschiedener Leitlinien einen festen Stellenwert bei der

  18. Pocket book on setting techniques for medical imaging. X-ray diagnostics, angiography, CT, MRT. 4. rev. and enl. ed.; Taschenatlas Einstelltechnik. Roentgendiagnostik, Angiografie, CT, MRT

    Energy Technology Data Exchange (ETDEWEB)

    Moeller, Torsten B.; Reif, Emil [Caritas-Krankenhaus, Dillingen/Saar (Germany)

    2009-07-01

    The pocketbook on setting techniques for medical imaging is concerned with the problem to prepare appropriate images for diagnostic purposes using modern high-technology instruments like x-ray diagnostics, angiography, computerized tomography and magnetic resonance tomography. The following issues are covered: Head, spinal column, upper extremities, lower extremities, thorax, gastrointestinal tract, intravenous organ examination, angiography, computerized tomography, NMR imaging.

  19. Individualisierender Unterricht in der Hochschullehre mittels einer IT-unterstützten Stationsarbeit

    Directory of Open Access Journals (Sweden)

    Kai Gebhardt

    2018-03-01

    Full Text Available Participants in university courses have different types of education and knowledge. In this case the didactic principle of differentiation is very important. We present the Analyzed Classroom teaching concept using an IT-system for analyze the learning progress. Students use tablets working on their exercises. The system creates a documented assessment of competence level for each student. The teacher can use the results for planning next steps into current exercise. We evaluated this concept in summer semester 2016 at Friedrich-Schiller-Universität Jena.

  20. Solar photocatalytic cleaning of polluted water. Solare Reinigung verschmutzter Waesser mittels Photokatalyse

    Energy Technology Data Exchange (ETDEWEB)

    Bockelmann, D

    1994-01-01

    Alternatively to biological, physical and chemical methods of waste water cleaning, photocatalysis can be employed. In this residue-free method, titanium dioxide particles are brought into contact with polluted water as photocatalysts. Under UV irradiation at wave-lengths below 400 nm, change carriers are generated in the semiconductor particles that act so intensely oxidizing as to completely degrade almost all organic pollutants in waste water. In this process, the ultra-violet part of the solar spectrum can be harnessed to generate oxidation equivalents. Thus, solar photocatalytic waste water cleaning is excellently suited for developing countries. (BWI)

  1. Mehrkörpersimulation eines ebenen Koppelgetriebes mittels Matlab / ADAMS -Co-Simulation

    OpenAIRE

    Gollee, Christian; Troll, Clemens

    2017-01-01

    Mit Hilfe der Matlab/ADAMS-Co-Simulation wird ein ebenes Koppelgetriebe (5- Gelenk) untersucht und anschließend die Wirkpaarung mit einem Stückgut betrachtet. Dabei werden verschiedene Modellierungsstufen angewendet und die Simulationsergebnisse Messergebnissen vom Versuchsstand gegenübergestellt. Daneben wird die grundlegende Herangehensweise beim Einsatz dieser Simulationswerkzeuge erläutert.

  2. Depths of controlled drillings by means of underground drives; Teufen von gesteuerten Bohrungen mittels Untertageantrieben

    Energy Technology Data Exchange (ETDEWEB)

    Hengevoss, Charly [Weatherford Ukraine LLC, Kiev (Ukraine); Homrighausen, Reiner [BAUER Resources GmbH, Schrobenhausen (Germany)

    2013-03-01

    Today, the most modern directional drilling technology not only is used in case of very deep drillings (deeper or longer than 2,000 meter) by means of deep-level drilling rigs, but also with small, highly mobile universal drilling rigs. Thus, drilling costs are reduced, and unconventional hydrocarbons (methane gas - oil shale and shale gas) deposits are explores economically. Furthermore, known near-surface petroleum deposits in Northern Germany as well as in other parts of the Earth (such as in Romania, the U.S.A. or in Canada) which extraction of petroleum is very low already are interesting economically. Furthermore, today it is possible to investigate with controlled drillings more economically and with more safe sites for a possibly final storage of highly radioactive wastes. Controlled drillings may give an answer to geotechnical questions on highly inaccessible on optimum points for drilling wells in order to plan underground cavities or to investigate tunnel axes geotechnical or hydrological.

  3. Light out-coupling from LEDs by means of metal nanoparticles; Lichtauskopplung aus LEDs mittels Metallnanoteilchen

    Energy Technology Data Exchange (ETDEWEB)

    Goehler, Tino

    2010-12-17

    The external quantum efficiency of light-emitting diodes (LEDs) based on Al- GaAs/InGaAlP is limited by total internal reflection because of the high refractive index (typically between 3 and 4) of the semiconductor. Metal nanoparticles (MNP) deposited on the surface of the LED can be used as dipole scatterers in order to enhance the emission of the LED. In this thesis, first, single gold nanoparticles of various sizes deposited on such an LED were investigated. A clear enhancement is detected as long as the dipole plasmon resonance of the particle is at a shorter wavelength than the LED emission. If the plasmon resonance coincides with the LED emission or is at a larger wavelength, the enhancement turns into suppression. Numerical simulations indicate that this latter effect is mainly caused by the particle quadrupole resonance producing extra absorption. Arrays of MNPs can be produced by a special mask technique called ''Fischer pattern nanolithography'' and manipulated in shape and size by additional steps. Originally, the MNPs produced by this technique are triangular in shape and turn out to suppress the LED emission. After transformation of the particles to spheres, a clear enhancement was detected. Light that would otherwise remain trapped inside the substrate is coupled out by resonant plasmonic scattering. Investigations on analogous structures on a transparent high-index material (GaP) indicate a stronger coupling between the particles than expected on the basis of literature data. (orig.)

  4. Bio- und Medizinethik in Ländern Mittel- und Osteuropas. Eine Hinführung

    Czech Academy of Sciences Publication Activity Database

    Bartíková, Monika; Banse, G.

    2007-01-01

    Roč. 16, č. 1 (2007), s. 5-20 ISSN 1210-0250 Institutional research plan: CEZ:AV0Z90090514 Keywords : Bioethics * Medical ethics * Middle and Eastern European Countries Subject RIV: AA - Philosophy ; Religion

  5. Funktionsintegration mittels Laserstrahlschmelzen - metallischer 3D-Druck für innovative Bauteile und Werkzeuge

    OpenAIRE

    Müller, Bernhard; Töppel, Thomas

    2017-01-01

    Laserstrahlschmelzen, ein pulverbettbasiertes additives Fertigungsverfahren, bietet zahlreiche Möglichkeiten, in Werkzeuge und Bauteile bestehende Funktionalitäten zu verbessern bzw. auch völlig neue Funktionalitäten zu integrieren. Dabei ist in drei Gruppen der Funktionalisierung zu unterscheiden: geometrische Funktionalisierung, werkstoffliche Funktionalisierung und integrative Funktionalisierung. Zur geometrischen Funktionalisierung zählen beispielsweise funktionale Hohlräume und Kanäle un...

  6. Erzeugung gleichverteilter Stichproben von Lozenge-Teilungen mittels Kopplung von Markovketten

    OpenAIRE

    Keller, Peter

    2011-01-01

    Aus dem Inhalt: 1 Einleitung 2 Eigenschaften der Lozengeteilungen 3 Coupling From The Past (CFTP) 4 Simulation von uniform verteilten Lozengeteilungen 5 Programmlisting und Diskussion der Implementierung 6 Ausblick A Anhang

  7. Engineering failure assessment methods applied to pressurized components; Bruchmechanische Bewertung druckfuehrender Komponenten mittels ingenieurmaessiger Bewertungsverfahren

    Energy Technology Data Exchange (ETDEWEB)

    Zerbst, U.; Beeck, F.; Scheider, I.; Brocks, W. [GKSS-Forschungszentrum Geesthacht GmbH (Germany). Inst. fuer Werkstofforschung

    1998-11-01

    Under the roof of SINTAP (Structural Integrity Assessment Procedures for European Industry), a European BRITE-EURAM project, a study is being carried out into the possibility of establishing on the basis of existing models a standard European flaw assessment method. The R6 Routine and the ETM are important, existing examples in this context. The paper presents the two methods, explaining their advantages and shortcomes as well as common features. Their applicability is shown by experiments with two pressure vessels subject to internal pressure and flawed by a surface crack or a through-wall crack, respectively. Both the R6 Routine and the ETM results have been compared with results of component tests carried out in the 1980s at TWI and are found to yield acceptable conservative, i.e. sufficiently safe, lifetime predictions, as they do not give lifetime assessments which unduly underestimate the effects of flaws under operational loads. (orig./CB) [Deutsch] Gegenwaertig wird im Rahmen von SINTAP (Structural Integrity Assessment Procedures for European Industries), einem europaeischen BRITE-EURAM-Projekt geprueft, inwieweit auf der Grundlage vorhandener Modelle eine einheitliche europaeische Fehlerbewertungsmethode erstellt werden kann. Eine zentrale Stellung kommt dabei Verfahren wie der R6-Routine und dem ETM zu. In der vorliegenden Arbeit wurden beide Methoden vorgestellt, wobei ihre Vor- und Nachteile, aber auch ihre Gemeinsamkeiten herausgearbeitet wurden. Die Anwendung wurde an zwei innendruckbelasteten Behaeltern mit Oberflaechen- bzw. wanddurchdringendem Riss demonstriert. Sowohl R6-Routine als auch ETM ergaben im Vergleich mit am TWI zu Beginn der 80er Jahre durchgefuehrten Bauteilexperimenten eine vertretbare konservative Vorhersage, d.h. eine nicht allzu grosse Unterschaetzung der ertragbaren Last der Bauteile. (orig.)

  8. The visualization of pannus in rheumatoid arthritis using NMR imaging. Pannusdarstellung bei rheumatoider Arthritis mittels Kernspintomographie

    Energy Technology Data Exchange (ETDEWEB)

    Schnarkowski, P. (Abt. fuer Roentgendiagnostik, Klinikum der Univ. Ulm (Germany)); Bader, C. (Abt. fuer Roentgendiagnostik, Klinikum der Univ. Ulm (Germany)); Goldmann, A. (Abt. fuer Roentgendiagnostik, Klinikum der Univ. Ulm (Germany)); Friedrich, J.M. (Abt. fuer Roentgendiagnostik, Klinikum der Univ. Ulm (Germany))

    1992-12-01

    The knee joints of 15 patients afflicted with rheumatoid arthritis were investigated using the method of nmr imaging. Parameters of investigation were the spin-echo and fast-field-echo sequences as well as the MR signal behaviour of proliferative synovial changes following intravenous administration of gadolinium dtpa. Pannus having formed on the articular surfaces or beneath the articular cartilages was distinguishable from other changes on the basis of the increased signal intensities to be observed after gadolinium dtpa had been given. (orig./GD)

  9. Untersuchungen zur oxidativen Bildung von Stickstoffmonoxid in Pflanzen sowie zur Visualisierung von Stickstoffmonoxid mittels Fluoreszenzfarbstoffen

    OpenAIRE

    Rümer, Stefan

    2013-01-01

    Stickstoffmonoxid (NO) ist ein gasförmiges, relativ stabiles Radikal, das in Pflanzen u. a. durch Reduktion aus Nitrit unter Katalyse des Enzyms Nitratreduktase gebildet wird. In tierischen Organismen wird NO dagegen über einen oxidativen Syntheseweg aus der Ami-nosäure L-Arginin katalysiert durch verschiedene Isoformen der NO-Synthasen (NOS) hergestellt. Es besitzt im tierischen System vielfältige Funktionen u. a. als Neurotransmitter sowie Blutfluss und -druck regulierendes Agens. Im Pflanz...

  10. Automation of the driving using the dynamic programming; Automatisierung des Treibens mittels diskreter dynamischer Programmierung

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Zongru; Buerger, Sebastian; Lohmann, Boris [Technische Univ. Muenchen, Garching (Germany). Lehrstuhl fuer Regelungstechnik

    2009-07-01

    Driving is a metal forming process throughout hammering in cold state. It can create almost any 2D and 3D metal sheets using universal tools. During driving, many parameters of the tools and the sheets affect the forming process, which inhibits a complete automation. In this paper, a model based control for a 2D driving process is proposed. The process of stretching L-shaped metal sheets is analytically modelled. Three phases, namely hybrid deformations, material flow as well as springback and inverse bending, describe the deformation process at one stroke. This results in a nonlinear (non-affine), time-discrete state space model. A model predictive controller (MPC) is then designed to determine the optimal control inputs at every time step. Thereby, an objective function that describes the costs from a start angle to an end condition is minimized by means of discrete dynamic programming (DDP). (orig.)

  11. Paraphrasensuche mittels word2vec und der Word Mover’s Distance im Altgriechischen

    Directory of Open Access Journals (Sweden)

    Marcus Pöckelmann

    2017-12-01

    Full Text Available To find receptions of Plato‘s work within the ancient Greek literature, automatic methods would be a useful assistance. Unfortunately, such methods are often knowledge-based and thus restricted to extensively annotated texts, which are not available to a sufficient extent for ancient Greek. In this article, we describe an approach that is based on the distributional hypotheses instead, to overcome the problem of missing annotations. This approach uses word2vec and the related Word Mover‘s Distance to determine phrases with similar meaning. Despite its experimental state, the method produces some meaningful results as shown in three examples.

  12. Enforcement of mandatory third party access based on antitrust law; Zwangsdurchleitung mittels Kartellrecht

    Energy Technology Data Exchange (ETDEWEB)

    Markert, K. [Bundeskartellamt, Berlin (Germany). 8. Beschlussabteilung

    1998-04-01

    Access of third parties to power transmission systems which up to now is governed in Germany by ownership rights will not run smoothly in future, although the general policy decision ended the dispute about the if, however leaving open aspects of the how. The problems arising in designing the how are currently displayed to the public by the disputes about conditions and model solutions reported from the telecommunications area, where deregulation is ahead of the developments in the energy sector. Obviously, the contention point is not technical feasibility of third party access, but the economic aspects and the conditions offered to competing suppliers depending on access to a transmission network. Hence it can be expected that there will be conflicts of interest that will have to be decided. The legal basis for conflict management is outlined in the recent amendment to the EnWG (German energy industry act), and jurisdiction will primarily rely on paragraph 6 of the act, referring to antitrust review. The contribution here gives an outline of the legal framework conditions governing enforcement of third party access to transmission systems in the future deregulated energy market. (orig./CB) [Deutsch] Die Oeffnung bisher geschlossener Netze fuer Drittwettbewerber verlaeuft auch dann, wenn ueber das `Ob` kein Streit mehr besteht, nicht konfliktfrei. Dies wird zur Zeit dem deutschen Publikum im Bereich der Telekommunikation mit fast taeglich neuen Varianten vorgefuehrt. Es geht dabei offensichtlich nicht um die technische Machbarkeit der Drittnutzung, sondern um die wirtschaftlichen Konditionen fuer Konkurrenten, die fuer ihr Leistungsangebot auf den Zugang zum Netz angewiesen sind. Konflikte ueber die Bedingungen dieses Zugangs sind daher vorprogrammiert, und es stellt sich die Frage, nach welchen Regeln und durch welche Gremien oder Institutionen solche Konflikte entschieden werden sollen. Der Beitrag umreisst die rechtlichen Rahmenbedingungen, die im neuen EnWG fuer den deregulierten Energiemarkt vorgesehen sind und erlaeutert speziell die Rolle des paragraph 6 EnWG als Grundlage der Durchsetzung des Zugangs Dritter zu Uebertragungsnetzen. (orig./CB)

  13. Investigation of relativistic laser-plasmas using nuclear diagnostics; Untersuchung relativistischer Laserplasmen mittels nukleardiagnostischer Verfahren

    Energy Technology Data Exchange (ETDEWEB)

    Guenther, Marc M.

    2011-01-19

    The present work explores with the development of a novel nuclear diagnostic method for the investigation of the electron dynamics in relativistic laser-plasma interactions. An additional aim of this work was the determination of the real laser peak intensity via the interaction of an intense laser short-pulse with a solid target. The nuclear diagnostics is based on a photo-neutron disintegration nuclear activation method. The main constituent of the nuclear diagnostic are novel pseudoalloic activation targets as a kind of calorimeter to measure the high-energy bremsstrahlung produced by relativistic electrons. The targets are composed of several stable isotopes with different ({gamma},xn)-reaction thresholds. The activated nuclides were identified via the characteristic gamma-ray decay spectrum by using high-resolution gamma spectroscopy after the laser irradiation. Via the gamma spectroscopy the ({gamma},xn)-reaction yields were determined. The high-energy bremsstrahlung spectrum has been deconvolved using a novel analysis method based on a modified Penfold-Leiss method. This facilitates the reconstruction of the spectrum of bremsstrahlung photons without any anticipated fit procedures. Furthermore, the characterization of the corresponding bremsstrahlung electrons in the interaction zone is accessible immediately. The consolidated findings about the properties of the relativistic electrons were used to determine the real peak intensity at the laser-plasma interaction zone. In the context of this work, experiments were performed at three different laser facilities. First Experiments were carried out at the 100 TW laser facility at Laboratoire pour l'Utilisation des Lasers Intense (LULI) in France and supplementary at the Vulcan laser facility at Rutherford Appleton Laboratory (RAL) in United Kingdom. The main part of the activation experiments were performed at the PHELIX laser facility (Petawatt High Energy Laser for heavy Ion EXperiments) at GSI-Helmholtzzentrum fuer Schwerionenforschung GmbH in Germany, which were the first nuclear activation experiments at this facility. The results obtained with the novel nuclear diagnostics method have lead to an advanced understanding of high-energy electrons produced in relativistic laser-plasma interactions. Particularly, the capability of the nuclear activation-based method to determine the real laser peak intensity at the relativistic laser-plasma interaction zone was demonstrated. (orig.)

  14. Results of ultrasonic disintegration of sewage sludge in practice; Ergebnisse des Praxiseinsatzes der Schlammdesintegration mittels Ultraschall

    Energy Technology Data Exchange (ETDEWEB)

    Friedrich, E. [IWE-Ingenieurgesellschaft fuer Wasser und Entsorgung mbH, Radebeul (Germany); Friedrich, H. [Fraunhofer-Institut fuer Keramische Technologien und Sinterwerkstoffe (IKTS), Dresden (Germany); Hielscher, H. [Hielscher GmbH, Teltow (Germany)

    1999-07-01

    Using high-performance ultrasonic sludge disintegration in different stages of sewage and sludge treatment is found to be an innovative approach for reducing the accruing amounts of sewage sludge in terms of both mass and volume. By means of practical tests with sludge disintegration at sewage treatment plants, its effects are demonstrated. (orig.) [German] Der Einsatz einer Hochleistungs-Ultraschalltechnik zur Schlammdesintegration in verschiedenen Stufen der Abwasser- und Schlammbehandlung zeigt sich als innovativer Loesungsweg zur weitestgehenden massenmaessigen sowie volumenmaessigen Minimierung des Klaerschlammanfalles. An Hand von Einsatzerprobungen der Desintegration in der Klaeranlagenpraxis werden die Effekte der Desintegration vorgestellt. (orig.)

  15. Efficient power supply using Power over Ethernet; Effiziente Stromversorgung mittels Power over Ethernet (PoE)

    Energy Technology Data Exchange (ETDEWEB)

    Huser, A.

    2005-07-01

    This final report for the Swiss Federal Office of Energy (SFOE) takes a look at methods of supplying small equipment such as Internet telephones, web cams, hubs, hard discs, audio equipment, point-of-sale terminals, game consoles etc. with power via their Ethernet connections. A short comparison is presented between Power over Ethernet (PoE) and other methods of supplying power along with data, including Universal Serial Bus (USB), FireWire and Powerline systems. The advantages of PoE over the use of separate power supply units are discussed and recommendations are made to the manufacturers and users of small peripheral equipment regarding the dimensioning and loading of such power supply systems.

  16. Procedures and means for determining enzyme activities. Verfahren und Mittel zur Bestimmung von Enzymaktivitaeten

    Energy Technology Data Exchange (ETDEWEB)

    Hunger, H; Behrendt, G; Schmidt, G

    1988-02-10

    Aim of the invention is a procedure for the determination of phosphorylating enzyme activity by using an improved means. Cellular extracts and cell lysates, resp., are contacted with surface carriers from natural and/or synthesized polymers, containing deprotonizable groups, in presence of /sup 32/P-..gamma..-ATP and, if necessary, of ATP. The phosphorylated antibiotic is evidenced by autoradiography or any other identifying procedure. Fields of application are molecular biology, genetic engineering, biotechnology and medical special fields.

  17. Institutionalisierung durch Imitation? Die Europäisierung des Parlamentarismus in Mittel- und Osteuropa / Aron Buzogany

    Index Scriptorium Estoniae

    Buzogany, Aron

    2015-01-01

    Artikli teemaks on parlamentarismi euroopastumine Kesk- ja Ida-Euroopa riikides (sh Eesti), püüdes leida vastus küsimusele, kuidas on rahvusriikide parlamendid suutnud institutsionaalselt euroopastumise väljakutsele vastata?

  18. Analyse von Kunststoffadditiven mittels Laserablation gekoppelt mit induktiv gekoppelter Plasma Massenspektrometrie

    OpenAIRE

    Börno, Fabian

    2016-01-01

    Die Laserablation gekoppelt mit der Massenspektrometrie mit induktiv gekoppeltem Plasma ist eine vielversprechende direkte Feststofftechnik, die sich jedoch bei der Analyse von Kunststoffen wegen des Mangels an matrixangepassten zertifizierten Referenzmaterialien nicht durchsetzen konnte. Vorherige Arbeiten belegen polymerabhängige Abtragsraten. Das oft als interner Standard verwendete Intensitätssignal des Kohlenstoffisotopes 13C zur Korrektur dieser Unterschiede wird in der Literatur kritis...

  19. Verfahren zum Fuegen zweier insbesondere rohrfoermiger Bauteile mittels eines wirkmedienbasierten Umformverfahrens und hiermit hergestelltes Werkstueck

    OpenAIRE

    Ortmann, S.; Unger, J.; Sterzing, A.

    2007-01-01

    DE 102005030587 A1 UPAB: 20070129 NOVELTY - In a process to joint two lengths of pipe e.g. automotive exhaust pipe, a sleeve-fit is sealed by the application of a tool exerting high internal pressure in the overlap zone forming a contiguous flush seal (3). Further claimed is a suitable tube product e.g. automotive exhaust pipe. USE - Process to join two sections of metal pipe e.g. automotive exhaust pipe. ADVANTAGE - The join zone exterior surface has an uninterrupted smooth form.

  20. Neutralisation of contaminated areas via rail; Neutralisation kontaminierter Gebiete mittels der Eisenbahn

    Energy Technology Data Exchange (ETDEWEB)

    Kunzewitsch, F.

    2007-07-01

    The problems that arose in dealing with the consequences of the Chernobyl disaster show that today we still do not have the requisite means and technology to neutralise radiation-contaminated areas effectively. Growing terrorism, ease of manufacture and the threat to use a 'dirty bomb' make it imperative to seek new ways of countering terrorism. Transport by rail offers an effective technical means for dealing with the aftermath of radiation contamination, including terrorist threats. (orig.)

  1. Musikerbriefe als Spiegel überregionaler Kulturbeziehungen in Mittel - und Osteuropa

    Directory of Open Access Journals (Sweden)

    Loos Helmut

    2002-01-01

    Full Text Available (nemački Traditionell ist die Musikgeschichtsschreibung nicht nur in Deutschland, sondern auch im östlichen Europa sehr stark nationalen Kriterien verpflichtet, und Musik wird vor allem als Nationalkultur verstanden. Dem gegenüber stehen viele Verflechtungen von Musikern, die in vergangenen Jahrhunderten häufig an vielen Orten Europas anwesend und tätig waren. Diese Verbindungen sind immer wieder einmal thematisiert, aber nur ansatzweise systematisch erforscht worden. Die überregionale Korrespondenz der Musiker im mittleren und östlichen Europa macht nicht nur europäische Verflechtungen sichtbar, sie liefert auch authentische Einschätzungen der Erfahrungen, die an verschiedenen Orten gesammelt wurden. Insgesamt ist zu erwarten, daß Europa im Spiegel der Musikerbriefe als der zusammenhängende Kulturraum im Musikleben erscheint, als der er bis weit ins 20. Jahrhundert hinein existierte.

  2. FOCJ as a Means of Regional Cooperation (FOCJ als Mittel regionaler Kooperation)

    Science.gov (United States)

    2008-03-01

    Steiner 1998. 54 ren, die sich durch regionale wie interregionale Kooperationen auszeichnen und oft komplette Wertsch6pfungsketten abdecken (Schmidt 2003...Manfred Steiner , Graz 2003 Friedrich, Peter, FOCJ: Bin neuer K6rperschaftstyp im Gesundheitswesen?, in- Li- beralisierung im Gesundheitswesen, hrsg. von...Economic Re- view,1969, Vo1. 59 (2), S. 479-487 Paptistella, Rudolf , Liquidititsoptimierung im Gemeindehaushalt. Der Einsatz der Datenverarbeitung im

  3. Pre- and post-operative evaluation of ventricular function, muscle mass and valve morphology by MR tomography in Ebstein's anomaly; Prae- und postoperative Beurteilung der ventrikulaeren Funktion, Muskelmasse und Klappenmorphologie bei der Ebstein-Anomalie mit der Magnetresonanztomographie

    Energy Technology Data Exchange (ETDEWEB)

    Gutberlet, M.; Oellinger, H.; Amthauer, H.; Hoffmann, T.; Felix, R. [Charite-Campus Virchow, Berlin (Germany). Klinik fuer Strahlenheilkunde; Ewert, P.; Nagdyman, N.; Lange, P. [Deutsches Herzzentrum Berlin (Germany). Abt. fuer Angeborene Herzfehler/Kinderkardiologie; Hetzer, R. [Deutsches Herzzentrum Berlin (Germany). Abt. fuer Herz-, Thorax- und Gefaesschirurgie

    2000-05-01

    Purpose: To evaluate the value of MRT with spin echo (SE) and CINE gradient echo (GE) sequences for the pre- and postoperative assessment of patients with Ebstein's anomaly. Methods: Twelve patients within the ages of four to 49 years (mean 22{+-}12 years) were examined pre- (n=5) or postoperatively (n=7) after tricuspid valve reconstruction with a 1.5 T scanner. For the anatomical assessment, an ECG-gated transverse SE-sequence, for the assessment of valve morphology and function as well as for volumetry a CINE GE-sequence with retrospective gating was used. With the use of the multislice-multiphase technique, after summing up the manually outlined epi- and endocardial areas, endsystolic (ESV) and enddiastolic volumes (EDV), ejection fraction (EF), stroke volume (SV), and muscle mass (MM) were calculated for both ventricles. Results: The differentiation of the displaced parts of the tricuspid valve (TV) was insufficient with static SE, but was possible in all patients with CINE-MRT. Like in Doppler echocardiography, a qualitative assessment of tricuspid insufficiency was possible in CINE-MRT, the mean incompetence grade preoperative was 1.8 ({+-}0.8), postoperative 0.7 ({+-}0.5). The mean RV-EF in the preoperative group was 41.8% ({+-}6.4), in the postoperative group 47.9% ({+-}10.6), the mean LV-EF preoperative 47.4% ({+-}8.5%), postoperative 63,0% ({+-}9.4). Conclusion: CINE-MRT should rather be used than SE for the assessment of valve morphology. EF, muscle mass and tricuspid incompetence can also be calculated pre- and postoperative with CINE-MRT. (orig.) [German] Zielsetzung: Zu ermitteln, welchen Beitrag die MRT mit der Spin-Echo-(SE) bzw. CINE-Gradienten-Echo-Sequenz (GE) zur prae- und postoperativen Beurteilung bei Patienten mit Ebstein-Anomalie leisten kann. Material und Methode: Es wurden 12 Patienten im Alter zwischen 4 und 49 Jahren (im Mittel 22{+-}12 Jahre) prae- (n=5) oder postoperativ (n=7) nach einer Trikuspidalklappenkonstruktion an einem 1

  4. Evaluation of injuries of the upper cervical spine in a postmortem study with digital radiography, CT and MRI; Evaluation experimentell erzeugter Verletzungen der oberen Halswirbelsaeule mit digitaler Roentgentechnik, Computertomographie und Magnetresonanztomographie

    Energy Technology Data Exchange (ETDEWEB)

    Obenauer, S.; Herold, T.; Fischer, U.; Grabbe, E. [Goettingen Univ. (Germany). Abt. fuer Roentgendiagnostik; Fadjasch, G.; Saternus, K.S. [Goettingen Univ. (Germany). Abt. fuer Rechtsmedizin; Koebke, J. [Koeln Univ. (Germany). Anatomisches Inst.

    1999-12-01

    obere Halswirbelsaeulen-Praeparate wurden nach definiertem Rotationstrauma sowie nach Praeparation mittels digitaler Roentgentechnik (DIMA Soft P41, Fa. Feinfokus), mittels CT (CTi, High Speed, GE) in konventioneller und in Spiraltechnik (Kollimation 1 mm, Pitch 1.0) sowie mit Hilfe der MRT (Magnetom Vision Siemens) in 2D- und 3D-Technik untersucht. Ergebnisse: Die Praeparation zeigte 6 Wirbelkoerperfrakturen, 5 Densfrakturen, 1 Fraktur des vorderen Atlasbogens, 4 knoecherne Ausrisse an den okzipitalen Kondylen und 6 Laesionen der Ligg. alaria. Die digitale Praeparateradiographie dokumentierte alle Frakturen und die 4 knoechernen Ausrissfrakturen am Condylus occipitalis. In der CT konnten alle Frakturen und ligamentaeren Verletzungen erkannt werden. Die 2D MRT wies 9 Frakturen sicher und 3 fraglich nach; die 3D MRT zeigte 7 Frakturen sicher und 5 fraglich. Von den 4 Ausrissfrakturen konnten 2 mit der 2D MRT und 1 mit der 3D MRT nachgewiesen werden. Ligamentaere Verletzungen waren sicher in der 2D MRT in 2/6 Faellen und in der 3D MRT in 1 Fall zu erkennen. Diskussion: In postmortalen Studien zeigt die CT gegenueber der digitalen Radiographie und der MRT in der Detektion von Frakturen und ligamentaeren Verletzungen der oberen Halswirbelsaeule eine Ueberlegenheit, wobei diese Ergebnisse nur bedingt auf Patienten nach Hochgeschwindigkeitstrauma uebertragbar sind. (orig.)

  5. MRI for troubleshooting detection of prostate cancer; MRT zur Problemloesung beim Nachweis des Prostatakarzinoms

    Energy Technology Data Exchange (ETDEWEB)

    Beyersdorff, D.; Hamm, B. [Universitaetsmedizin Berlin, Charite Mitte (Germany)

    2005-06-01

    Prostate cancer is the most common malignancy in males. Men aged 50 and older are recommended to undergo an annual digital rectal examination (DRE) and determination of prostate-specific antigen (PSA) in serum for early detection. However, prostate biopsies guided by transrectal ultrasound (TRUS) come up negative for cancer in many patients despite having PSA levels above 4 ng/ml. T2-weighted Magnetic Resonance Imaging (MRI) is able to represent the prostate including the surrounding anatomy and depict suspicious areas of low intensity within a high-intensity peripheral zone. MRI has a higher sensitivity for detecting prostate carcinomas than DRE and TRUS in patients having an elevated PSA value and a negative core biopsy. However, its specificity is poor since other abnormalities such as prostatic intraepithelial neoplasia (PIN), prostatitis, scars, or haemmorrhage have a similar MRI appearance. The use of additional techniques such as MR spectroscopy and contrast-enhanced dynamic MRI improves sensitivity, but in particular it improves the specificity of tumor detection. Newly developed biopsy devices enable the performance of targeted biopsies in areas that appear suspicious in the MRI. (orig.)

  6. CT and MRI in progressive multifocal leukoencephalopathy. CT und MRT der progressiven multifokalen Leukenzephalopathie (PML)

    Energy Technology Data Exchange (ETDEWEB)

    Lanfermann, H. (Inst. und Poliklinik fuer Radiologische Diagnostik, Koeln Univ. (Germany)); Heindel, W. (Inst. und Poliklinik fuer Radiologische Diagnostik, Koeln Univ. (Germany)); Schroeder, R. (Neuropathologie des Inst. fuer Pathologie, Koeln Univ. (Germany)); Lackner, K. (Inst. und Poliklinik fuer Radiologische Diagnostik, Koeln Univ. (Germany))

    1994-07-01

    Radiological findings and course of progressive multifocal leukoencephalopathy in 14 patients (1 woman, 13 men; 13 HIV seropositive, 1 chronic lymphatic leukaemia) were analysed retrospectively and correlated with clinical symptoms. A total of 21 CT and 16 MRI studies were evaluated. CT scans and MR images of 9 patients, which had been obtained in less than two weeks, could be compared to each other. MRI was superior to CT: 6 lesions with a diameter of 1 cm and below were not detected on CT scans, in 5 patients the extent of lesions was underestimated. Cortical involvement, mass effect or signs of atrophy were missing. Only 1 of 65 lesions showed a tiny enhancement after Gd injection. Due to the pattern and spread of lesions, which showed a close correlation to the neurologic symptoms, three different types of PML are suggested: 1. Initial precentral demyelinisation with contralateral hemiparesis (n=8); 2. lesions in temporo-occipital locations with visual disturbances (n=2); 3. predominantly bilateral lesions of cerebellar white matter with ataxia (n=4). (orig.)

  7. Transposition of the great arteries in MRI; Transposition der grossen Arterien im MRT des Herzens

    Energy Technology Data Exchange (ETDEWEB)

    Zaehringer, C.; Leiner, T.; Maki, J.H.; Potthast, S.

    2014-02-15

    The contribution on transposition of the great arteries (TGA) in the heart NMR images covers the following issues: different forms of TGA (dextro-TGA and levo-TGA), therapeutic options, long-term complication of TGA and the importance of heart NMR imaging in case of TGA.

  8. Management of breast lesions detectable only on MRI; Abklaerung ausschliesslich MRT-detektierbarer Mammalaesionen

    Energy Technology Data Exchange (ETDEWEB)

    Siegmann-Luz, K.C.; Bahrs, S.D.; Preibsch, H.; Hattermann, V.; Claussen, C.D. [Universitaetsklinikum Tuebingen (Germany). Abt. Diagnostische und Interventionelle Radiologie

    2014-01-15

    Breast MR imaging has become established as the most sensitive imaging method for diagnosing breast cancer. As a result of the increasing examination volume and improved image quality, the number of breast lesions detected only on MRI and requiring further clarification has risen in recent years. According to the S3-guideline 'Diagnosis, Therapy, and Follow-Up of Breast Cancer' as revised in July 2012, institutions performing breast MRI should provide the option of an MRI-guided intervention for clarification. This review describes the indications, methods and results of MRI-guided interventions for the clarification of breast lesions only visible on MRI. Recent guidelines and study results are also addressed and alternative methods and pitfalls are presented. (orig.)

  9. Gliomatosis cerebri: The diagnostic potential of MRI. Gliomatosis cerebri: Diagnostisches Potential der MRT

    Energy Technology Data Exchange (ETDEWEB)

    Rodiek, S.O.; Hufnagl, J.M. (Staedtisches Krankenhaus Muenchen-Bogenhausen (Germany). Abt. fuer Roentgendiagnostik und Nuklearmedizin Staedtisches Krankenhaus Muenchen-Bogenhausen (Germany). Abt. fuer Neuropsychologie)

    1991-07-01

    Gliomatosis cerebri is a rare tumor of neuroepithelial origin in middle aged persons. MRI predominantly shows a bilateral and diffuse infiltration of midline adjacent brain structures including medulla. Areas with focal anaplasia occasionally reveal an accumulation of contrast media. The diffuse tumor manifestation requires a differentiation from encephalitis and demyelinating diseases with a similar distribution pattern of lesions. Three cases have been examined. In conclusion the performance of MRI including control and brain biopsy are indicated to establish an in vivo diagnosis. (orig./GDG).

  10. MRT measurements of the CSF spaces in HIV associated cerebral atrophy

    International Nuclear Information System (INIS)

    Handwerker, M.; Krahe, T.; Klinker, H.; Schindler, R.

    1992-01-01

    The CSF volume of 45 patients with HIV infection was measured at various clinical stages and the results compared with 24 normals. 60% of all patients showed increased CSF spaces as an indication of cerebral atrophy. Serial measurements were particularly valuable during the early stages of atrophy since there is marked variation in the normal CSF volume. Conventional measurements, with the exception of the width of the third ventricle, were much less sensitive than these quantitative measurements. Classification of HIF infection according to the clinical stage was useful since CSF volume and volume increase correlated with the stage of HIV infection. (orig.) [de

  11. MRT of abdomen and pelvis. 2. tot. rev. and enl. ed.

    International Nuclear Information System (INIS)

    Hamm, B.; Krestin, G.P.; Laniado, M.; Nicolas, V.; Taupitz, M.

    2007-01-01

    The book offers maximum expert knowledge from an experienced team of authors, first-class reference image material, clear guidelines for indications and actions also in comparison with other techniques, and a detailed presentation of examination sequences with table protocols. There are clear schematic drawings, guidelines, key findings and tables for differential diagnosis, and a list of possible misinterpretations. The authors present contributions on MR angiography and examination of infants and take account of all modern trends and indications. The book facilitates introduction to the subject, reading-up, and quick reference. It provides practical support at the workplace and is written in a user-friendly manner. There is a new chapter ''rectum'', and the book contains more than 1000 illustrations. (orig.)

  12. Functional MRI and neurophysiological aspects of obesity; Funktionelle MRT und neurophysiologische Aspekte der Adipositas

    Energy Technology Data Exchange (ETDEWEB)

    Sztrokay, A.; Reiser, M.; Meindl, T. [Klinikum der Ludwig-Maximilians-Universitaet Muenchen, Campus Grosshadern, Institut fuer Klinische Radiologie, Muenchen (Germany); Gutyrchik, E. [Klinikum der Ludwig-Maximilians-Universitaet Muenchen, Institut fuer Medizinische Psychologie, Muenchen (Germany)

    2011-05-15

    Functional magnetic resonance imaging studies have revealed that metabolic signals and food stimuli activate the mesocorticolimbic neural network involved in processing the reward system. Activation is influenced by obesity and hunger and many recent brain imaging studies have detected that food and drug stimuli activate many of the same reward circuits. These findings have implications for obesity prevention and therapy. Educational efforts need to be directed towards those at increased risk of becoming obese and the food industry has to be involved in providing and promoting healthier food options. Given that visual food stimuli are potent triggers of desire, seductive advertising of high calorie foods directed towards children should be curtailed. The application of non-invasive brain imaging methodologies to the study of hedonic and homeostatic eating behavior represents a novel and important experimental approach. Further advances in imaging technology and improved experimental designs will provide new and important insights into human ingestive behavior that may lead to new developments in behavioral and pharmacological therapies. (orig.) [German] Bildgebende Studien zeigen, dass Nahrungsreize und metabolische Stimuli das mesokortikolimbische System und somit das Belohnungssystem aktivieren. Die Aktivierung dieses Systems wird sowohl von Hunger als auch Uebergewicht beeinflusst. In bildgebenden Studien wurde nachgewiesen, dass Reize in Form von Essen aehnlich wie Suchtmittel den Belohnungskreislauf aktivieren. Diese Erkenntnis hat Auswirkungen auf die Praevention und Therapie der Adipositas. Die Nahrungsmittelindustrie ist gefordert, gesuenderes Essen zu produzieren und entsprechend zu bewerben. Vor dem Hintergrund, dass die visuelle Stimulation durch Nahrungsmittel ein potenzieller Trigger fuer das Verlangen nach Essen ist, sollte die direkt auf Kinder ausgerichtete Bewerbung hochkalorischer Nahrungsmittel reduziert werden. Die Anwendung nichtinvasiver bildgebender Verfahren fuer die Erforschung von gesundem, homoeostatischem und im Gegensatz dazu hedonischem Essensverhalten repraesentiert einen neuen und wichtigen wissenschaftlichen Ansatz. Weitere Fortschritte auf dem Gebiet der bildgebenden Verfahren und eine Verbesserung des experimentellen Designs koennen neue und bedeutende Erkenntnisse hinsichtlich des menschlichen Essverhaltens liefern. Diese koennten zu neuen Entwicklungen in der Pharmako- und Verhaltenstherapie der Adipositas fuehren. (orig.)

  13. Management of intracranial incidental findings on brain MRI; Management intrakranieller Zufallsbefunde in der MRT-Bildgebung

    Energy Technology Data Exchange (ETDEWEB)

    Langner, S.; Buelow, R.; Kirsch, M. [University Medicine Greifswald (Germany). Inst. for Diagnostic Radiology and Neuroradiology; Fleck, S. [University Medicine Greifswald (Germany). Dept. of Neurosurgery; Angermaier, A. [University Medicine Greifswald (Germany). Dept. of Neurology

    2016-12-15

    The wider use of MRI for imaging of the head in both research and clinical practice has led to an increasing number of intracranial incidental findings. Most of these findings have no immediate medical consequences. Nevertheless, knowledge of common intracranial incidental findings and their clinical relevance is necessary to adequately discuss the findings with the patient. Based on the author's experiences from a large population-based study, the most common incidental MR findings in the brain will be presented, discussing their clinical relevance and giving recommendations for management according to the current literature and guidelines.

  14. NMR imaging of the liver. Diagnostics, differential diagnostics, therapeutic approaches; MRT der Leber. Diagnostik, Differenzialdiagnostik, Therapieansaetze

    Energy Technology Data Exchange (ETDEWEB)

    Fischbach, Frank; Fischbach, Katharina [Universitaetsklinikum Magdeburg A.oe.R. (Germany). Klinik fuer Radiologie und Nuklearmedizin

    2017-03-01

    The book on NMR imaging of the liver covers the following issues: Fundamentals of NMR imaging, T1-weighted imaging; T2-weighted imaging, diffusion-weighted imaging, cavernous hemangioma, focal nodular hyperplasy; hepatocellular adenoma, hepatocellulas carcinoma, cholangiocellular carcinoma, hepatic metastases.

  15. MRT of scaphoid pseudo-arthrosis using Gd-DTPA. Staging and clinical correlation

    International Nuclear Information System (INIS)

    Vogl, T.J.; Beutel, F.; Wilhelm, K.; Tempka, A.; Schedel, H.; Haas, R.; Felix, R.

    1994-01-01

    During a period of two years, 134 patients with pseudo-arthrosis of the scaphoid were examined by conventional radiography and by MRI in the course of a prospective study. The aim of the study was to define radiological staging using contrast enhanced MRI in order to improve the prognostic criteria. All MRI examinations were carried out with a 1.5 Tesla scanner (SP63) using a surface coil and T 1 weighted spin echo sequences in sagittal and frontal projection and frontal FLASH T 2 -sequences and axial spin echo T 2 sequences. The T 1 weighted SE sequences in frontal projection were carried out before and after iv contrast (0.1 mmol Gd-DTPA/kg KG). All sequences were compared with conventional radiographs and the operative findings. Eight patients in stage 0 showed high signal intensity of both fragments in T 1 weighted SE sequences and at surgery there was good vascularisation. In 22 cases there was reduced signal intensity in at least one fragment (stage I). 45 patients with scaphoid pseudo-arthrosis showed complete signal loss but marked contrast uptake with still vital nuclei at surgery (stage II). In 22 patients, there was no increase in signal intensity after contrast and complete loss of vitality of the fragments at surgery. Staging was not possible in 37 patients because of previous operative intervention. The use of contrast enhanced MRI provides additional information compared with conventional radiography or plain MRI. (orig.) [de

  16. Dynamic function MR of the cervical vertebral column. Dynamische Funktions-MRT der Halswirbelsaeule

    Energy Technology Data Exchange (ETDEWEB)

    Naegele, M.; Woell, B.; Reiser, M. (Radiologische Universitaetsklinik, Bonn (Germany)); Koch, W. (Orthopaedische Universitaetsklinik, Bonn (Germany)); Kaden, B. (Neurochirurgische Universitaetsklinik, Bonn (Germany))

    1992-09-01

    To obtain functional studies of the cervical spine, a device has been developed which allows MRI examinations to be carried out in five different degrees of flexion. T[sub 1] and T[sub 2][sup *] weighted FFE sequences were used. Dynamic functional MRI was performed on 5 normals and 31 patients (5 disc herniation, 4 whiplash injuries, 6 spinal canal stenoses, 14 laminectomies and spinal fusions, 2 rheumatoid arthritis). The relationship of the spinal cord to the bony and ligamentous components in different degrees of flexion was particularly well shown in whiplash injury, spinal stenosis and postoperative situations. (orig.).

  17. MRT letter: Guided filtering of image focus volume for 3D shape recovery of microscopic objects.

    Science.gov (United States)

    Mahmood, Muhammad Tariq

    2014-12-01

    In this letter, a shape from focus (SFF) method is proposed that utilizes the guided image filtering to enhance the image focus volume efficiently. First, image focus volume is computed using a conventional focus measure. Then each layer of image focus volume is filtered using guided filtering. In this work, the all-in-focus image, which can be obtained from the initial focus volume, is used as guidance image. Finally, improved depth map is obtained from the filtered image focus volume by maximizing the focus measure along the optical axis. The proposed SFF method is efficient and provides better depth maps. The improved performance is highlighted by conducting several experiments using image sequences of simulated and real microscopic objects. The comparative analysis demonstrates the effectiveness of the proposed SFF method. © 2014 Wiley Periodicals, Inc.

  18. MRT letter: Contrast-enhanced computed tomographic imaging of soft callus formation in fracture healing.

    Science.gov (United States)

    Hayward, Lauren Nicole Miller; de Bakker, Chantal Marie-Jeanne; Lusic, Hrvoje; Gerstenfeld, Louis Charles; Grinstaff, Mark W; Morgan, Elise Feng-I

    2012-01-01

    Formation of a cartilaginous soft callus at the site of a bone fracture is a pivotal stage in the healing process. Noninvasive, or even nondestructive, imaging of soft callus formation can be an important tool in experimental and pre-clinical studies of fracture repair. However, the low X-ray attenuation of cartilage renders the soft callus nearly invisible in radiographs. This study utilized a recently developed, cationic, iodinated contrast agent in conjunction with micro-computed tomography to identify cartilage in fracture calluses in the femora of C57BL/6J and C3H/HeJ mice. Fracture calluses were scanned before and after incubation in the contrast agent. The set of pre-incubation images was registered against and then subtracted from the set of post-incubation images, resulting in a three-dimensional map of the locations of cartilage in the callus, as labeled by the contrast agent. This map was then compared to histology from a previous study. The results showed that the locations where the contrast agent collected in relatively high concentrations were similar to those of the cartilage. The contrast agent also identified a significant difference between the two strains of mice in the percentage of the callus occupied by cartilage, indicating that this method of contrast-enhanced computed tomography may be an effective technique for nondestructive, early evaluation of fracture healing. Copyright © 2011 Wiley Periodicals, Inc.

  19. 1. 5 MRT of the hyaline articular cartilage of the knee joint

    Energy Technology Data Exchange (ETDEWEB)

    Adam, G.; Bohndorf, K.; Krasny, R.; Guenther, R.W.; Prescher, A.

    1988-06-01

    MRI is a new method for imaging the knee joint. There is still some uncertainty regarding the extent and the signal from hyaline articular cartilage. MRI images were therefore compared with anatomical and histological preparations of the knee joint and the difference between MRI and the anatomical sections have been determined. It was shown that demonstration of hyaline cartilage was obscured by an artifact. Further investigations are required to determine the cause of this artifact and to achieve accurate imaging of hyaline cartilage by MRI.

  20. Metabolic disorders with typical alterations in MRI; Stoffwechselstoerungen mit typischen Veraenderungen im MRT

    Energy Technology Data Exchange (ETDEWEB)

    Warmuth-Metz, M. [Klinikum der Universitaet Wuerzburg, Abteilung fuer Neuroradiologie, Wuerzburg (Germany)

    2010-09-15

    The classification of metabolic disorders according to the etiology is not practical for neuroradiological purposes because the underlying defect does not uniformly transform into morphological characteristics. Therefore typical MR and clinical features of some easily identifiable metabolic disorders are presented. Canavan disease, Pelizaeus-Merzbacher disease, Alexander disease, X-chromosomal adrenoleukodystrophy and adrenomyeloneuropathy, mitochondrial disorders, such as MELAS (mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes) and Leigh syndrome as well as L-2-hydroxyglutaric aciduria are presented. (orig.) [German] Die Einteilung von Stoffwechselstoerungen nach ihrer Aetiologie ist fuer den diagnostischen Neuroradiologen nicht sinnvoll, da sich aus der zugrunde liegenden Stoerung keine Rueckschluesse auf die zu erwartende MR-Morphologie ziehen lassen. Deshalb sollen anhand typischer bildmorphologischer Veraenderungen in Zusammenschau mit den jeweiligen klinischen Charakteristika einige leicht einzuordnende Stoffwechselstoerungen dargestellt werden. Es handelt sich um den Morbus Canavan, Morbus Pelizaeus-Merzbacher, Morbus Alexander, die X-chromosomal vererbte Adrenoleukodystrophie und Adrenomyeloneuropathie, die mitochondrialen Stoerungen MELAS (mitochondriale Enzephalomyopathie, Laktazidose und Stroke-like-Episoden) und Leigh-Syndrom sowie die L-2-Hydroxyglutarazidurie. (orig.)

  1. NMR of the rotator cuff. An update; MRT der Rotatorenmanschette. Ein Update

    Energy Technology Data Exchange (ETDEWEB)

    Kreitner, Karl-Friedrich; Maehringer-Kunz, Aline [Universitaetsmedizin Mainz (Germany). Klinik und Poliklinik fuer Diagnostische und Interventionelle Radiologie

    2016-03-15

    The rotator cuff consists of the tendons of the supscapularis, supraspinatus, infraspinatus and teres minor muscles. This group of muscles performs multiple functions and is often stressed during various activities. This explains, why rotator cuff disease is common and the most often cause of shoulder pain and dysfunction in adults. MR imaging still is the most important imaging modality in assessment of rotator cuff disease. It enables the radiologist to make an accurate diagnosis, the basis for an appropriate management. In this article, current concepts with regard to anatomy and imaging diagnosis will be reviewed. The discussion of the complex anatomy is followed by normal and pathologic MR imaging appearances of the rotator cuff including tendinopathy and tearing, and concluding with a review of the postoperative cuff.

  2. Gadolinium DTPA as oral contrast medium for MRT of the pancreas

    International Nuclear Information System (INIS)

    Neumann, K.; Kaminsky, S.; Gogoll, M.; Langer, M.; Felix, R.

    1991-01-01

    52 patients with normal pancreas, pancreatitis and pancreatic tumors were examined by magnetic resonance imaging (Magnetom 0,5 T). Using T 1 -, proton density- and T 2 -weighted spin-echo sequences images were obtained before and after oral administration of Gadolinium-DTPA (Gd-DTPA, 1 mM, 15 g/l Mannit, 5-13 ml/kg). Gd-DTPA resulted in hyperintense labeling of small bowel in all sequences and improved visualization of pancreatic head, body and tail in 15, 14 and 7 of 27 patients with normal pancreas and in 17, 8 and 6 of 25 patients with diseased pancreas. Better delineation of pseudocysts and tumorous gut wall invasion were diagnostically profitable. With regard to motion artifact reduced MRI of the intestine using fast sequences Gd-DTPA may be a suitable oral contrast agent to improve the imaging of the pancreas. (orig.) [de

  3. Anatomy of the skull base and the cranial nerves in slice imaging; Anatomie der Schaedelbasis und Hirnnerven in der Schnittbildgebung

    Energy Technology Data Exchange (ETDEWEB)

    Bink, A.; Berkefeld, J.; Zanella, F. [Klinikum der Goethe-Universitaet Frankfurt, Institut fuer Neuroradiologie, Frankfurt am Main (Germany)

    2009-07-15

    Computed tomography (CT) and magnetic resonance imaging (MRI) are suitable methods for examination of the skull base. Whereas CT is used to evaluate mainly bone destruction e.g. for planning surgical therapy, MRI is used to show pathologies in the soft tissue and bone invasion. High resolution and thin slice thickness are indispensible for both modalities of skull base imaging. Detailed anatomical knowledge is necessary even for correct planning of the examination procedures. This knowledge is a requirement to be able to recognize and interpret pathologies. MRI is the method of choice for examining the cranial nerves. The total path of a cranial nerve can be visualized by choosing different sequences taking into account the tissue surrounding this cranial nerve. This article summarizes examination methods of the skull base in CT and MRI, gives a detailed description of the anatomy and illustrates it with image examples. (orig.) [German] Zur Untersuchung der Schaedelbasis sind sowohl die Computertomographie (CT) als auch Magnetresonanztomographie (MRT) geeignet. Waehrend mittels CT vorzugsweise die exakte knoecherne Ausbreitung von Pathologien z. B. zur operativen Therapieplanung erfasst werden, dient die MRT sowohl der Darstellung von Pathologien bzgl. ihrer Ausbreitung im Weichteilgewebe als auch dem Nachweis knoecherner Infiltration. Bei der Untersuchung der Schaedelbasis wird eine hochaufloesende Darstellung mit geringer Schichtdicke fuer beide Modalitaeten angestrebt. Die genaue Kenntnis der Anatomie ist bereits bei der Untersuchungsplanung notwendig. Sie ist zudem Voraussetzung fuer das Erkennen und die korrekte Interpretation von Pathologien. Die MRT ist die bildgebende Methode der Wahl zur Abklaerung von Pathologien der Hirnnerven. Dabei ist es durch gezielte Sequenzauswahl, die sich nach den die Hirnnerven umgebenen Strukturen richtet, moeglich, den gesamten Verlauf der Hirnnerven zu beurteilen. Dieser Artikel beschreibt die Untersuchung der Schaedelbasis

  4. Pediatric brain tumors of neuroepithelial tissue; Hirntumoren des neuroepithelialen Gewebes im Kindesalter

    Energy Technology Data Exchange (ETDEWEB)

    Papanagiotou, P.; Politi, M. [Klinikum Bremen-Mitte/Bremen-Ost, Klinik fuer Diagnostische und Interventionelle Neuroradiologie, Bremen (Germany); Bergmann, M. [Klinikum Bremen-Mitte, Institut fuer Klinische Neuropathologie, Bremen (Germany); Pekrun, A. [Klinikum Bremen-Mitte, Klinik fuer Kinder- und Jugendmedizin, paed. Haematologie/Onkologie, Neonatologie, Bremen (Germany); Juergens, K.U. [Klinikum Bremen-Mitte, ZEMODI-Zentrum fuer moderne Diagnostik, MRT, Nuklearmedizin und PET-CT, Bremen (Germany)

    2014-08-15

    Tumors of neuroepithelial tissue represent the largest group of pediatric brain tumors by far and has therefore been divided into several discrete tumor subtypes each corresponding to a specific component of the neuropil. The neuropil contains several subtypes of glial cells, including astrocytes, oligodendrocytes, ependymal cells and modified ependymal cells that form the choroid plexus. This review discusses the imaging aspects of the most common pediatric tumors of neuroepithelial tissue. (orig.) [German] Tumoren des neuroepithelialen Gewebes stellen die mit Abstand groesste Gruppe der paediatrischen Hirntumoren dar und werden je nach deren Ursprung in diversen Subtypen unterteilt. Das Neuropil beinhaltet diverse Subtypen von Gliazellen: Astrozyten, Oligodendrozyten, ependymale Zellen und modifizierte ependymale Zellen, die den Plexus choroideus formen. In diesem Review werden die bildgebenden Aspekte mittels CT und MRT der haeufigsten Tumoren des neuroepithelialen Gewebes diskutiert. (orig.)

  5. Quantitative Analyse und Visualisierung der Herzfunktionen

    Science.gov (United States)

    Sauer, Anne; Schwarz, Tobias; Engel, Nicole; Seitel, Mathias; Kenngott, Hannes; Mohrhardt, Carsten; Loßnitzer, Dirk; Giannitsis, Evangelos; Katus, Hugo A.; Meinzer, Hans-Peter

    Die computergestützte bildbasierte Analyse der Herzfunktionen ist mittlerweile Standard in der Kardiologie. Die verfügbaren Produkte erfordern meist ein hohes Maß an Benutzerinteraktion und somit einen erhöhten Zeitaufwand. In dieser Arbeit wird ein Ansatz vorgestellt, der dem Kardiologen eine größtenteils automatische Analyse der Herzfunktionen mittels MRT-Bilddaten ermöglicht und damit Zeitersparnis schafft. Hierbei werden alle relevanten herzphysiologsichen Parameter berechnet und mithilfe von Diagrammen und Graphen visualisiert. Diese Berechnungen werden evaluiert, indem die ermittelten Werte mit manuell vermessenen verglichen werden. Der hierbei berechnete mittlere Fehler liegt mit 2,85 mm für die Wanddicke und 1,61 mm für die Wanddickenzunahme immer noch im Bereich einer Pixelgrösse der verwendeten Bilder.

  6. Evaluation of the energy consumption and climate comfort by means of a complete vehicle simulation; Energieverbrauchs- und Klimakomfortbewertung mittels Gesamtfahrzeugsimulation

    Energy Technology Data Exchange (ETDEWEB)

    Petr, Philipp [Technische Univ. Braunschweig (Germany). Inst. fuer Thermodynamik; Niedersaechsisches Forschungszentrum Fahrzeugtechnik (NFF), Braunschweig (Germany); Mustafa, Rashad [Technische Univ. Braunschweig (Germany). Inst. fuer Fahrzeugtechnik; Niedersaechsisches Forschungszentrum Fahrzeugtechnik (NFF), Braunschweig (Germany); Schulze, Mirko [Technische Univ. Braunschweig (Germany). Inst. fuer Verbrennungskraftmaschinen; Niedersaechsisches Forschungszentrum Fahrzeugtechnik (NFF), Braunschweig (Germany)

    2012-11-01

    Intelligent thermal management for vehicles can significantly reduce energy consumption and improve the climatic comfort. This paper describes an approach of how to analyse and evaluate vehicle thermal management techniques and their combination with different test cycles in a connected vehicle environment as examples. The focus will be particularly on the methodological approach. Based on the energetic analysis of the considered drivetrain topologies conclusions can be drawn about the complex thermal and dynamic relations. The analysis in turn is based on the results of the full vehicle simulation and refers to reference driving cycles and relevant environmental conditions. The energy flow analyses derived from the simulation are used in order to develop suitable thermal management techniques, to evaluate their potential and to integrate them in the vehicle. In addition to the influence of the measures the potential resulting from an intelligent combination of techniques and their control strategies are identified. The energy consumption advantage as well as the improved heating of the passenger compartment - especially at low ambient temperatures - will be evaluated. (orig.)

  7. Positionsspezifischer Nachweis und relative Quantifizierung von Modifikationen des alpha-s1-Caseins in Milch mittels MALDI-TOF-MS

    OpenAIRE

    Vollmer, Gregor

    2013-01-01

    Milch und Milchprodukte spielen eine bedeutende Rolle in der menschlichen Ernährung. Vor der Abgabe an den Verbraucher wird Milch in den allermeisten Fällen hitzebehandelt, um mikrobielle Stabilität sicherzustellen und die Haltbarkeit zu verlängern. Allerdings kann diese Hitzebehandlung die in Milch enthaltenen Nährstoffe, unter anderem Kohlenhydrate, Lipide, Proteine und Vitamine, erheblich schädigen. Vitamine werden durch starke Erhitzung zerstört, bei den Lipiden kann es zu Abbaureaktionen...

  8. Ein empirischer Vergleich der Prozessaufzeichnungsmethoden Mouselab und Eyetracking bei Präferenzmessungen mittels Choice-based Conjoint Analyse

    DEFF Research Database (Denmark)

    Meissner, Martin; Decker, Reinhold; Pfeiffer, Jella

    2010-01-01

    , instead of eye tracking, influences the way information is acquired and processed and whether respectively how this affects the validity of CBC results. The empirical study shows that Mouselab in fact changes the information acquisition process, but this does not affect the quality of the preference......In choice-based conjoint (CBC) analysis respondents’ decisions in choice settings are used to determine relevant attributes and attribute levels of the products considered. Yet, the cognitive process preceding the choice decision is usually ignored. The eye tracking technique can be used to gain...... additional insights on how information is processed in the context of preference measurement. However, because of the technical requirements, an efficient application of eye tracking is often hard to realize in managerial practice. Therefore, the use of alternative process-tracing approaches like Mouselab...

  9. An integral IT-approach using EAI architectures; Der integrale IT-Ansatz mittels EAI-Architekturen

    Energy Technology Data Exchange (ETDEWEB)

    Zengaffinen, A.

    2003-07-01

    This article examines the question if there is any information technology (IT) on the market that meets the needs of an energy utility for an integral and comprehensive tool to control its operations. The possibilities offered by so-called 'Enterprise Application Integration' (EAI) are examined and the intelligent linking-up of various sources of data is discussed. The current and future situations in typical utilities are looked at, where the unbundling of activities threatens to make business processes that are already complex even more so. Various models for the integration of existing IT applications such those using 'peer-to-peer' architectures, data warehousing and 'middleware' applications as well as their advantages and disadvantages are discussed. An example is given of integration using a 'middleware' solution in the maintenance area. A well-tried project implementation process is described.

  10. Die Inszenierung der Toten. Italienische Kriegsgräberstätten im Alpenraum als Mittel faschistischer Propaganda

    Directory of Open Access Journals (Sweden)

    Tragbar, Klaus

    2017-07-01

    Full Text Available For the self-perception of the Kingdom of Italy, founded as late as 1861, the soldiers killed in action during WW I played a particular role. The war memorials built for them along the front between the Stelvio Pass and the Isonzo River, the frontier to the former Austro-Hungarian Empire, are a case in point. After their seizure of power in 1922, the Italian fascists radically converted the memorial culture from the mourning of the dead to their celebration as fascist martyrs. New war memorials were built, now rather driven by the ideas of heroism and sacrifice for the nation – and for future wars. These new war memorials were also erected in regions where no fighting had taken place during WW I, as in South Tyrol, at the Brenner or the Reschen Pass. This was a clear indication of their function as an instrument for political propaganda.

  11. Modeling for pipe decontamination by means of high-frequency percussive action; Modellerstellung fuer die Rohrdekontamination mittels hochfrequenter Schlagwirkung

    Energy Technology Data Exchange (ETDEWEB)

    Aminy, Akramullah

    2014-07-30

    The formation of persistent scales in pipes causes lower flow rates and therefore represents an economic problem. The contamination of scales - which usually is the case in most industrial applications - also poses a problem with respect to the scales' environmental compatibility. The currently applied techniques for the removal of these scales involve the use of auxiliary materials which accumulate large quantities of secondary waste that is costly to be disposed of. In this research, an environmentally friendly removal method for tubing scales was developed and qualified. The analysis of the currently used technologies formed the basis for the analysis and systematic evaluation of different principles of removal action methods. Consequently, a concept for a new impact based removal method was established. The mechanism of this technique is the application of a high-frequency percussive action by a geometrically defined tool. The impact on the scales cracks their surface and causes their fracture and thus the detachment from the pipes. Compared to alternative removal methods this proposed technique works without any auxiliary material and thus prevents the production of secondary waste. The investigation of the impact process was carried out in a newly developed test rig. In this test rig, the maximum forces of the percussive tool were measured with shear force sensors on the tubing surface and the resulting stress on the tube was obtained. The evaluation of the measured values using the method of descriptive statistics demonstrated that the high dynamic stress of the tubing due to the complex tool motion is based on a normal distribution. Based on this evaluation, the effects of the influencing factors on the stress of the tubings were systematically measured and outlined in a mathematical model. This model describes the dependency of the tool and the process of related factors that influences the tubing stress. According to this model, this stress is composed of the different impact intensities and frequencies which are transmitted by the percussive tool. The stress model was then simulated and the effects of the influencing factors were demonstrated for different parameters combinations. For the investigation of the removal process through this new percussive technique, cement stone was used to simulate different types of scales inside tubings. The effects of the influencing factors of the tool and the process have finally been identified in extensive ablation studies where the effectiveness of the percussive technique for the removal of stubborn tubing scales is being demonstrated.

  12. New X-ray refractometry for nondestructive characterization of high performance composites; Charakterisierung von Hochleistungsverbundwerkstoffen mittels Roentgenrefraktion

    Energy Technology Data Exchange (ETDEWEB)

    Harbich, K W; Hentschel, M P [Bundesanstalt fuer Materialforschung und -pruefung, Berlin (Germany). Labor 6.22 ` ` Zerstoerungsfreie Charakterisierung von Materialstrukturen` `

    1994-12-01

    Facing the basic relevance of single fibre bonding for the mechanical properties of composites relating testing methods are requested. These have not yet been satisfactory. A new nondestructive method provides a fast and precise tool to determine the fraction of debonded fibres by refraction of X-rays at the interface of fibres in composites. The systematic analysis of thinwalled unidirectional tapes of carbon fibres in thermoplastics results in specific characteristics of different lots. These were successfully exploited for the improvement of the processing parameters. The new method is selective for fibre orientation. The detection of specific defects in composites of orthogonal fibre orientation is performed by X-ray refraction topography. First investigations reveal clearly the detectibility and identification of impact damages and paper inserts. (orig.)

  13. Tropospheric trace gas measurement by tunable diode laser spectroscopy. Final report. Messung troposphaerischer Spurengase mittels Dioden-Laser-Spektroskopie. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Burrows, J P; Crutzen, P J; Harris, G W; Klemp, D; Johnson, T J; Perner, D; Wienhold, F G; Zenker, T

    1991-01-01

    This final report is concerned with tropospheric trace gas measurements by Tunable Diode Laser Spectroscopy (TDLAS). A TDLAS instrument was built which simultaneously measures four selected trace gases and is sufficiently sensitive for use in 'clean' air conditions. The instrument is the first of its kind to be used for measurements aboard ship platforms in clean marine air. In order to guarantee that the instrument function continuously for several weeks at a time under the difficult conditions encountered at sea, a variety of innovative technical developments were necessary. The TDLAS instrument was used to investigate boundary layer tropospheric chemistry in one engineering test and four field campaigns. Three of the field campaigns took place on board the German research vessels. The measurements on board the research vessels enabled different types of tropospheric air to be investigated: (i) clean maritime air; (ii) maritime regions influenced by continental sources of trace gases and pollutants, in particular the coastal region around the west coast of Africa was thoroughly investigated under downwind conditions. A large set of data of simultaneous measurements of key tropospheric trace gases (NO{sub 2}, CO, HCHO, H{sub 2}O{sub 2} and O{sub 3}) were obtained which help paint a more complete picture of tropospheric oxidation cycles. The first measurements of H{sub 2}O{sub 2} in the remote marine boundary layer are reported. In selected regions successful TDLAS measurements of HCl and COS were obtained, results in themselves of importance. Intercomparisons of TDLAS and other measurement techniques were successfully undertaken. (orig./BBR).

  14. Sales gas hydrocarbon dew point control with a refrigeration plant; Konditionierung des Kohlenwasserstofftaupunktes im Verkaufsgas mittels einer Kaelteanlage

    Energy Technology Data Exchange (ETDEWEB)

    Konieczny, J.; Scsepka, H. [OMV Aktiengesellschaft, Exploration and Production, Gaenserndorf (Austria)

    2004-11-01

    A new refrigeration plant was put on stream in the gas plant Aderklaa, Austria in the fall 2003. The quality criteria inherent to hydrocarbon dew point of the sales gas have already been accomplished. The contract (Allgemeinen Netzzugangsbedingungen) defines the hydrocarbon dew point at the value of 0 C with a pressure ranging 0-70 bar(g). Process facilities are a gas/gas-heat exchanger and a low-temperature-separator flanged to the chiller. A propane cycle produces the required cooling energy. The propane cycle consists of two propane compressors, one of them as back up, a condenser, an accumulator and an evaporator. About 50,000 m{sup 3} (V{sub n}) sales gas per hour are produced at a working pressure of 65 bar(g). Process gas coming from the sweetening plant Aderklaa I is lowered to a temperature of -14 C, where approx. 250 litres liquid hydrocarbons per hour are separated and saved. When the refrigeration plant was designed, attention was given to the operating costs to keep them low. This could be achieved by maximising surface area for heat transfer in the gas/gas-heat exchanger. After commissioning and start-up, full operability of the new plant was tested and documented. The pre-set project goals were accomplished, with respect to both the technical point of view and the economic aspects. (orig.)

  15. Intra-group separation of rare earths using new organic phosphorus ligands; Intragruppentrennung Seltener Erden mittels neuer phosphororganischer Liganden

    Energy Technology Data Exchange (ETDEWEB)

    Hadic, Sanela

    2017-10-01

    Rare earth elements (REE) have unique magnetic, photophysical, and chemical properties and they are therefore used in numerous high-technology applications. However, to this day, the isolation of pure rare earths from primary and secondary raw materials is very challenging. In this work, the hydrometallurgical separation of neighboring rare earths (e.g., praseodymium/ neodymium) was optimized with novel selective extraction agents. The separation of rare earths (yttrium and all lanthanides except promethium) was investigated with fourteen new organophosphorus compounds. Oxygen-bearing phosphinic acids yielded good separation results for heavy rare earths (dysprosium to lutetium). For light rare earths (lanthanum to neodymium), particularly high separation factors were realized with synergistic systems containing an aromatic dithiophosphinic acid and a co-extractant, such as tris (2-ethylhexyl) phosphate (TEHP). Optimization studies of the latter extraction system revealed an extremely high separation factor (SF) of 4.21 between praseodymium and neodymium. Another focus of this work was to understand the extraction mechanism. With the aid of nuclear magnetic resonance spectroscopy ({sup 1}H-NMR) and time-resolved laser fluorescence spectroscopy (TRLFS), the complex stoichiometry of promising extraction systems was examined. Studies revealed a dependency between the selectivity for rare earths and the coordination number of the formed complexes. In addition, temperature-dependent extraction experiments were performed and thermodynamic data (ΔG, ΔH, and ΔS) determined. These data provided additional information about the origin of selectivity for neighboring rare earths. With regard to the industrial capability of the investigated extraction systems, the chemical durability of ligands was studied under process-relevant conditions. Qualitative and quantitative analytical methods (e.g., GC-MS) were used in long-term experiments to determine the ligand degradation. After the decomposition products had been identified, reaction paths were proposed. The impact of this decomposition on the separation of rare earths was followed, in single extraction experiments, over a period of up to several months.

  16. Kommunikationsschulung mittels "Standardisierter Eltern" im Fachbereich der Pädiatrie [Communication training using "standardised parents" in paediatrics

    Directory of Open Access Journals (Sweden)

    Hoffmann, Katja

    2007-05-01

    Full Text Available [english] Introduction: Communicative competence is essential for daily medical routine. The usefulness of communication-trainings for physicians is described in various publications. However, specific trainings in paediatrics are rarely found. A characteristic for paediatric work is that the primary communication is not only with the patient – the child – but also with the parents. Beside self-assessment external assessment by parents can be used for evaluation of paediatrician’s communicative skills.Methods: 28 paediatric residents (intervention group n = 14; control group n = 14 of the University Children’s Hospital of Heidelberg took part in a communication training using standardised parents and -patients (SP, video recording and feedback by peers, SPs and supervisors. Data of self-evaluated communicative competence in contact with parents was collected from all participants before and after the training of the intervention group. In addition there was an assessment of parents’ satisfaction with the paediatricians-parents communication concerning their children’s treatment nine weeks before and nine weeks after the training (n = 248. A follow-up survey to record the transfer into clinical practice was conducted with the participants after six months.Results: After the training participants of the intervention group showed an increased feeling of communicative competence in reference to communicative situations that were explicitly practiced in the training. The external assessment by parents generally showed a positive evaluation of paediatricians’ communication skills. However, a group effect was not found. In the follow-up survey participants reported an improved self-perception and specific elements of the training that facilitated the daily clinical practice with parents and their children. Discussion: The training of specific relevant clinical situations lead to an increase in perceived communicative competence and competence in handling difficult encounters with parents. Communication trainings should be integrated not only into the medical student education but also into post-graduate education curricula. [german] Einführung: Kommunikative Kompetenzen sind wesentlich für den ärztlichen Alltag. In der Literatur wird vielfach der Nutzen von Kommunikationsschulungen für Ärzte beschrieben, über gezielte Schulungen für den Fachbereich Pädiatrie finden sich nur vereinzelt Berichte. Die Besonderheit der pädiatrischen Versorgung besteht dabei im Wesentlichen darin, dass nicht nur die Kommunikation zum Patienten – dem Kind –, sondern auch zu dessen Eltern oder Bezugspersonen eine entscheidende Rolle spielt. Zur Überprüfung kommunikativer Fähigkeiten von Pädiatern können neben Selbsteinschätzungen auch Fremdeinschätzungen durch Eltern dienen.Methode: 28 Assistenzärzte (Interventionsgruppe n = 14; Kontrollgruppe n = 14 der Universitätsklinik für Kinder- und Jugendmedizin in Heidelberg nahmen an einer Kommunikationsschulung teil. Diese beinhaltete Übungsgespräche mit standardisierten Eltern und -Patienten (SP, Videoaufzeichnungen sowie Feedback von SPs, Peers und Supervisoren. Daten zur Selbsteinschätzung der eigenen kommunikativen Kompetenz wurden vor und nach der Schulung der Interventionsgruppe von allen Teilnehmern erhoben. Weiterhin wurde neun Wochen vor und neun Wochen nach Abschluss der Schulung eine Elternbefragung bei n = 248 Eltern durchgeführt, in der die Zufriedenheit mit dem Arztkontakt hinsichtlich der Arzt-Eltern Kommunikation erfasst wurde. Nach 6 Monaten schloss sich eine Nachbefragung bei den Teilnehmern zum Transfer in den Klinikalltag an.Ergebnis: Bei den Teilnehmern der Interventionsgruppe zeigte sich im Gegensatz zur Kontrollgruppe nach Abschluss der Schulung eine signifikante Steigerung der subjektiven Kompetenzeinschätzung in Bezug auf die kommunikativen Situationen, die speziell in der Schulung trainiert wurden. Die Fremdeinschätzung durch die Eltern ergab eine generell sehr positive Bewertung der Ärzte, es ließ sich jedoch kein Gruppeneffekt nachweisen. Im Langezeitverlauf berichteten die Teilnehmer von einer verbesserten Selbstwahrnehmung und benannten konkrete Elemente der Schulung, die ihnen die tägliche klinische Arbeit im Kontakt mit Eltern erkrankter Kinder erleichterten.Diskussion: Das Training von spezifischen, für den klinischen Alltag typischen Situationen führt zu einer Verbesserung der Selbsteinschätzung kommunikativer Kompetenzen bezüglich des Umgangs mit schwierigen Situationen im Elternkontakt. Eine Integration von Kommunikationsschulungen nicht nur in das Medizinstudium, sondern auch in postgraduierte Ausbildungs-Curricula erscheint daher sinnvoll.

  17. Beschreibung des Korngrößenwachstums bei der Wirbelschicht-Sprühgranulation mittels statistischer Modelle

    OpenAIRE

    Schinzinger, Oliver

    2004-01-01

    Ein wichtiger Schritt bei der Herstellung von Tabletten ist die Aufarbeitung eines meist sehr feinen, schlecht fließfähigen Pulvers zu einem besser fließenden Granulat. Da die Granulation aus den drei Teilprozessen Mischen, Granulieren und Trocknen besteht, werden heutzutage Granulationen in der Wirbelschicht durchgeführt. Eine Wirbelschichtapparatur vereint die drei Teilprozesse in einem Gerät. Die Wirbelschichtgranulation wird durch eine große Anzahl an Parametern beeinflusst, die in Prozes...

  18. Gadolinium recovery from aqueous pharmaceutical residuals by pulsed electrical discharge; Rueckgewinnung von Gadolinium aus pharmazeutischen Abwaessern mittels gepulster elektrischer Entladung

    Energy Technology Data Exchange (ETDEWEB)

    Lorenz, Tom; Froehlich, Peter [TU Bergakademie Freiberg (Germany); Seifert, Martin; Jacob-Seifert, Karin [FNE Entsorgungsdienste GmbH, Freiberg (Germany)

    2017-02-15

    Advanced oxidation process (AOP) is an oxidation step releasing reactive oxygen species by pulsed electrical discharge in aqueous systems. In contrast to processes generating ozone by external UV radiation this method is feasible for turbid liquids with solid particles. This method is currently used in particular in the field of purification of chemically polluted waste waters. In the present application AOP is applied for partial degradation of the organic ligand system of a gadolinium X-ray contrast agent to separate gadolinium subsequently by adding caustic soda to precipitate > 99% of gadolinium.

  19. Big Data als Informationsquelle für regionales Arbeitsmarkt-Monitoring: Online-Stellenanzeigen analysieren mittels "Jobfeed"

    OpenAIRE

    Plaimauer, Claudia

    2016-01-01

    1 Einleitung. 2 Herausforderungen bei der Interpretation von Stelleninseraten. 3 Herausforderungen im Umgang mit Big Data und semantischen Technologien. 4 Die Big-Data-Plattform "Jobfeed". 5 Ausblick. 6 Literatur.

  20. Positioning strategies for decentralized energy resources providing reactive power voltage control; Anlagenauswahl und -positionierung zur Spannungsstuetzung mittels Blindleistungsmanagement dezentraler Erzeugungsanlagen

    Energy Technology Data Exchange (ETDEWEB)

    Matrose, Claas; Goedde, Markus; Cramer, Moritz; Potratz, Fabian; Pollok, Thomas; Schnettler, Armin [RWTH Aachen Univ. (Germany). Inst. fuer Hochspannungstechnik

    2012-07-01

    The integration of decentralized generation into power distribution grids in Germany has reached a level at which more and more grid reinforcement is required in order to keep voltages within the given limits. The consumption of reactive power by decentralized generation systems can reduce the voltage rise, which is caused by active power in-feed of such systems. Caused by different characteristics of overhead lines and cables, this effect significantly varies. Parameter studies of four commonly used types of lines, of different power ratings of decentralized generation systems as well as different lengths of lines can quantify the effects. It can be shown that - depending on the characteristics of a specific grid - the grid capacity for power in-feed can be increased by factors between 1.5 and 10. (orig.)

  1. Image processing. Volumetric analysis with a digital image processing system. [GAMMA]. Bildverarbeitung. Volumetrie mittels eines digitalen Bildverarbeitungssystems

    Energy Technology Data Exchange (ETDEWEB)

    Kindler, M; Radtke, F; Demel, G

    1986-01-01

    The book is arranged in seven sections, describing various applications of volumetric analysis using image processing systems, and various methods of diagnostic evaluation of images obtained by gamma scintigraphy, cardic catheterisation, and echocardiography. A dynamic ventricular phantom is explained that has been developed for checking and calibration for safe examination of patient, the phantom allowing extensive simulation of volumetric and hemodynamic conditions of the human heart: One section discusses the program development for image processing, referring to a number of different computer systems. The equipment described includes a small non-expensive PC system, as well as a standardized nuclear medical diagnostic system, and a computer system especially suited to image processing.

  2. Development and standard of batter slope monitoring by means of simple telemetering. Entwicklung und Stand von Boeschungsbeobachtungen mittels einfacher Distanzmessungen

    Energy Technology Data Exchange (ETDEWEB)

    Duddek, H

    1990-11-01

    In the search for mainly automatic measuring techniques that furnish real-time areal data on deformations in marginal batters of opencast workings, it was decided inter alia to adopt the technique of direct linear measurement across the workings at the brown coal opencast mines in the Rhineland. The present paper describes the development of this technique from the use of instruments which initially were operated manually to the introduction of automatic measuring stations. The successful application of this technique in all the opencast workings in the Rhineland brown coal mining area is discussed. Since the accuracy obtained in electro-optical telemetering depends to a large extent on the meteorological conditions, it can hardly be increased with the instruments at present available. Hence, it is essential that two-colour telemeters which are perfected for field-work and are not refraction-prone should be developed. (orig.).

  3. Development and testing of passive autocatalytic recombiners cooled by heat pipes; Entwicklung und Erprobung mittels Heatpipe gekuehlter katalytischer Rekombinatoren

    Energy Technology Data Exchange (ETDEWEB)

    Granzow, Christoph

    2012-11-26

    A severe accident in a nuclear power plant (NPP) can lead to core damage in conjunction with the release of large amounts of hydrogen. As hydrogen mitigation measure, passive autocatalytic recombiners (PARs) are used in today's pressurized water reactors. PARs recombine hydrogen and oxygen contained in the air to steam. The heat from this exothermic reaction causes the catalyst and its surroundings to heat up. If parts of the PAR heat up above the ignition temperature of the gas mixture, a spontaneous deflagration or detonation can occur. The aim of this work is the prevention of such high temperatures by means of passive cooling of the catalyst with heat pipes. Heat pipes are completely passive heat exchanger with a very high effective thermal conductivity. For a deeper understanding of the reaction kinetics at lower temperatures, single catalytic coated heat pipes are studied in a flow reactor. The development of a modular small-scale PAR model is then based on a test series with cooled catalyst sheets. Finally, the PAR model is tested inside a pressure vessel under boundary conditions similar to a real NPP. The experiments show, that the temperatures of the cooled catalytic sheets stay significantly below the temperature of the uncooled sheets and below the ignition temperature of the gas mixture under any set boundary conditions, although no significant reduction of the conversion efficiency can be observed. As a last point, a mathematical model of the reaction kinetics of the recombination process as well as a model of the fluid dynamic and thermohydraulic processes in a heat pipe are developed with the data obtained from the experiments.

  4. Monitoring effects of river restoration on groundwater with radon; Ueberwachung der Auswirkungen von Flussaufweitungen auf das Grundwasser mittels Radon

    Energy Technology Data Exchange (ETDEWEB)

    Hoehn, Eduard [Eawag, Eidgenoessische Anstalt fuer Wasserversorgung, Abwasserreinigung und Gewaesserschutz, Duebendorf (Switzerland)

    2007-03-15

    The restoration of the perialpine river Toess in a floodplain of northern Switzerland (Linsental) included the removal of bank reinforcements and tracer studies in the river and in oberservation wells of the adjacent alluvial groundwater. The river water is continuously recharging the aquifer system and the groundwater is used extensively as drinking water. Radon activity concentrations of freshly infiltrated groundwater are interpreted as radon groundwater age between the river and a well. A first flood after the restoration operations resulted in a widening of the river bed and in a reduction of the flow distance to the wells. Sixteen days after a second flood, the results of radon measurements were compared with those from before the restoration. The radon age of the groundwater between the river and the wells decreased, probably as a result of the reduction of the flow distances. Concentrations of autochthonous and coliform bacteria increased after the restoration operation and even more one day after the first flood. Thus the findings on the bacteria corroborate the interpretation of the radon concentrations. The restoration has not yet reduced the quality of the groundwater, which is pumped for drinking water. The study is contributing to the solution of land-use conflicts between river restoration and the supply of drinking water from the alluvial groundwater. (orig.) [German] Die Renaturierung des voralpinen Flusses Toess in der Schotterebene des Linsentals (suedlich Winterthur, Nordschweiz) mit einer Befreiung von seinen Uferverbauungen gab Anlass zu Traceruntersuchungen im Fluss und im Grundwasser des kiessandigen Schotters. In diesem Gebiet infiltriert der Fluss ueberall und immer natuerlicherweise ins Grundwasser, welches stark als Trinkwasser genutzt wird. Radon-Aktivitaetskonzentrationen von frisch infiltriertem Grundwasser wurden interpretiert als Radon-Grundwasseralter fuer Strecken zwischen dem Fluss und Grundwasserbeobachtungsrohren. Nach einem ersten Hochwasser bewirkten die Renaturierungsmassnahmen eine Aufweitung des Ufers und eine Verringerung der Fliessdistanz des infiltrierenden Wassers zu den Rohren. Im Vergleich mit Radonmessungen vor diesen Massnahmen, resultierten Messungen, die 16 Tage nach einem zweiten Hochwasser durchgefuehrt wurden, in einer Verringerung der Radon-Grundwasseralter auf dieser Strecke, dies als Folge der Verringerung der Fliessdistanzen. Die Zahlen von autochthonen und coliformen Bakterien stiegen bereits bei einer Messung nach der Befreiung des Ufers und dann besonders bei einer Messung einen Tag nach dem ersten Hochwasser. Damit stuetzen diese Befunde die Interpretation der Radonmessungen. Auf die Trinkwasserqualitaet wirkte sich die Flussaufweitung hingegen bislang nicht aus. Solche Untersuchungen leisten einen Beitrag zur Loesung des raumwirksamen Nutzungskonflikts zwischen Flussrenaturierung und Grundwassernutzung als Trinkwasser. (orig.)

  5. Thermal spraying of corrosion protection layers in biogas plants; Erzeugung von Korrosionsschutzschichten fuer Bioenergieanlagen mittels Thermischen Spritzens

    Energy Technology Data Exchange (ETDEWEB)

    Crimmann, P.; Dimaczek, G.; Faulstich, M. [ATZ Entwicklungszentrum, Sulzbach-Rosenberg (Germany)

    2004-07-01

    Corrosion in plants for the energetic conversion of biomass is a severe problem that often causes premature damage of components. Thermal spraying is a process for the creation of corrosion protection layer. An advantage of thermal spraying is that as well as each material can be used as layer material. First practical results demonstrated that thermal spraying has the potential to create coatings to protect components against high temperature corrosion as well as biocorrosion. Layer materials are for example nickel base alloys (high temperature corrosion) and titan alloys (biocorrosion). Further investigations are necessary in order to examine whether cost-efficient coatings also contribute to the corrosion protection (e.g. polymer materials against biocorrosion). (orig.)

  6. Procedure and means for determining aminoglucoside phosphotransferase activity. Verfahren und Mittel zur Bestimmung der Aminoglucosid-Phosphotransferaseaktivitaet

    Energy Technology Data Exchange (ETDEWEB)

    Hunger, H D; Behrendt, G; Schmidt, G; Merkel, D

    1988-02-10

    A method and means are described for determining the activity of aminoglucoside phosphotransferase. Possible applications are genetic engineering, biotechnology and medicine. Cell lysates or cell extracts are contacted with a surface carrier on cellulose basis, in the presence of a mixture of ATP and /sup 32/P-ATP, with the phosphorylated kanamycin made visible in the solid phase by autoradiography.

  7. Legal frameworks of the unconventional exploration of natural gas by means of Fracking; Rechtliche Rahmenbedingungen der unkonventionellen Erdgasfoerderung mittels Fracking

    Energy Technology Data Exchange (ETDEWEB)

    Rossnagel, Alexander; Hentschel, Anja; Polzer, Andreas

    2012-07-01

    ExxonMobile projects the exploration of natural gas from so-called unconventional deposits by means of the hydraulic fracturing procedure (Fracking). In view of the public concerns, ExxonMobile engaged a neutral group of experts to develop the 'risk study Fracting'. This risk study has to investigate the legal framework for the evaluation of the risks and impacts of an unconventional exploration of natural gas by means of Fracking. The legal instruments to control these risks and impacts also are mentioned. The legal framework for the evaluation and for the compensation for damages within the realization of these risks is described. Furthermore, the most important proposals from the legal discussion are reported. Recommendations are drawn up with respect to the improvement of the legal framework and its controlling instruments.

  8. Legal frameworks of the unconventional exploration of natural gas by means of Fracking; Rechtliche Rahmenbedingungen der unkonventionellen Erdgasfoerderung mittels Fracking

    Energy Technology Data Exchange (ETDEWEB)

    Rossnagel, Alexander; Hentschel, Anja; Polzer, Andreas

    2012-07-01

    ExxonMobile projects the exploration of natural gas from so-called unconventional deposits by means of the hydraulic fracturing procedure (Fracking). In view of the public concerns, ExxonMobile engaged a neutral group of experts to develop the 'risk study Fracting'. This risk study has to investigate the legal framework for the evaluation of the risks and impacts of an unconventional exploration of natural gas by means of Fracking. The legal instruments to control these risks and impacts also are mentioned. The legal framework for the evaluation and for the compensation for damages within the realization of these risks is described. Furthermore, the most important proposals from the legal discussion are reported. Recommendations are drawn up with respect to the improvement of the legal framework and its controlling instruments.

  9. Underground vehicle monitoring and material tracking by wireless data transmission; Untertaegige Fahrzeugueberwachung und Materialverfolgung mittels drahtloser Datenuebertragung

    Energy Technology Data Exchange (ETDEWEB)

    Huenefeld, R. [Technische Hochschule Aachen (Germany). Lehrstuhl und Inst. fuer Bergwerks- und Huettenmaschinenkunde; Kuepper, T. [XGraphic Ingenieurgesellschaft mbH, Aachen (Germany)

    2008-04-17

    Satellite-assisted navigation and position detection by GPS (Global Positioning System) are the state of the art in surface fleet management. The system cannot, of course, be used underground. With the introduction of WLAN networks, pocket PCs and WLAN Handys a technological platform, on the basis of which comparable services can be offered, has meanwhile become available also in the underground mining industry. Various applications, which were developed for the specified technological environment, are described in this contribution. They are used for communication, vehicle monitoring and position tracking, but are also suitable for complicated tasks. A typical example is the automation of monorails, in which communication with the vehicle and visualisation of the vehicle data and position are important. (orig.)

  10. Cartilaginous tumours; MR appearance and correlation with histopathology. Chondromatoese Tumoren in der MRT; Erscheinungsbild in Abhaengigkeit von Lokalisation und Histopathologie

    Energy Technology Data Exchange (ETDEWEB)

    Stiglbauer, R. (Vienna Univ. (Austria). MR-Institut der Medizinischen Fakultaet und Klinik fuer Radiodiagnostik); Boehm, G. (Vienna Univ. (Austria). Inst. fuer Klinische Pathologie)

    1993-02-01

    19 patients with histologically verified cartilaginous tumours (chondromas, chondrosarcomas) were examined with magnetic resonance imaging (MRI) in order to assess differences regarding the MR appearance of these tumours which would provide information on the biological behaviour of these lesions. MR findings were then correlated with histopathology. With regard to the signal behaviour of cartilaginous tumours a good correlation with histopathology could be established insofar as the relatively hypocellular tumours composed of hyaline cartilage exhibited a high signal level on T[sub 2]-weighted images. There were no significant differences regarding signal characteristics of cartilaginous tumours in various anatomical locations. However, lesions located in the pelvis and the long bones showed predominantly peripheral enhancement whereas tumours of the skull base and larynx exhibited diffuse enhancement patterns in the majority of cases. 10 tumours (6 benign, 4 malignant) exhibited a lobular appearance. No relevant information in respect of tumour grading could be obtained. (orig.)

  11. fMRI and DTI in delayed development of number processing; fMRT und DTI bei Entwicklungsverzoegerung der Zahlenverarbeitung

    Energy Technology Data Exchange (ETDEWEB)

    Krick, C.M.; Neuhaus, A.; Klewin, C.; Woerner, T.; Kreis, S.; Reith, W. [Universitaetsklinikum des Saarlandes, Klinik fuer Diagnostische und Interventionelle Neuroradiologie, Homburg/Saar (Germany)

    2015-09-15

    The neuronal correlate of the current cultural performance arose from developmental processes that can be observed by functional and anatomical magnetic resonance imaging. The velocity of these maturation processes occurs differently between adolescents, causing implications for both school career and academic performance. Regarding spatial-numerical cognition the myelinization of the superior longitudinal bundle appears to be crucial because this fiber connection intermediates between the linguistic nature of number words and conception of their spatial-numerical magnitude. The neuroscientific observation of anatomical brain maturation and its influence on school-relevant number processing may be helpful for educational purposes as well as for school psychology. (orig.) [German] Das neuronale Fundament unserer Kulturleistungen ist einem Entwicklungsprozess unterworfen, der ueber funktionelle und anatomische Magnetresonanzbildgebung beobachtet werden kann. Diese Reifungsprozesse verlaufen bei verschiedenen Jugendlichen unterschiedlich rasch, sodass sich darueber auch Wechselwirkungen mit der Schullaufbahn und schulischen Leistungen ergeben. Im Fall der raeumlich-numerischen Kognition spielt u. a. die Myelinisierung des Fasciculus longitudinalis superior eine entscheidende Rolle, weil diese Faserverbindung fuer das Vermitteln zwischen sprachlichem Zahlenkode und numerischer Groessenvorstellung relevant ist. Die neurowissenschaftliche Darstellung anatomischer Reifeprozesse und deren Einfluss auf die schulrelevanten Prozesse der Zahlenverarbeitung koennen im Lichte paedagogischer oder schulpsychologischer Ueberlegungen dienlich erscheinen. (orig.)

  12. Anato-metabolic fusion of PET, CT and MRI images; Anatometabolische Bildfusion von PET, CT und MRT

    Energy Technology Data Exchange (ETDEWEB)

    Przetak, C.; Baum, R.P.; Niesen, A. [Zentralklinik Bad Berka (Germany). Klinik fuer Nuklearmedizin/PET-Zentrum; Slomka, P. [University of Western Ontario, Toronto (Canada). Health Sciences Centre; Proeschild, A.; Leonhardi, J. [Zentralklinik Bad Berka (Germany). Inst. fuer bildgebende Diagnostik

    2000-12-01

    The fusion of cross-sectional images - especially in oncology - appears to be a very helpful tool to improve the diagnostic and therapeutic accuracy. Though many advantages exist, image fusion is applied routinely only in a few hospitals. To introduce image fusion as a common procedure, technical and logistical conditions have to be fulfilled which are related to long term archiving of digital data, data transfer and improvement of the available software in terms of usefulness and documentation. The accuracy of coregistration and the quality of image fusion has to be validated by further controlled studies. (orig.) [German] Zur Erhoehung der diagnostischen und therapeutischen Sicherheit ist die Fusion von Schnittbildern verschiedener tomographischer Verfahren insbesondere in der Onkologie sehr hilfreich. Trotz bestehender Vorteile hat die Bildfusion bisher nur in einzelnen Zentren Einzug in die nuklearmedizinische und radiologische Routinediagnostik gefunden. Um die Bildfusion allgemein einsetzen zu koennen, sind bestimmte technische und logistische Voraussetzungen notwendig. Dies betrifft die Langzeitarchivierung von diagitalen Daten, die Moeglichkeiten zur Datenuebertragung und die Weiterentwicklung der verfuegbaren Software, auch was den Bedienkomfort und die Dokumentation anbelangt. Zudem ist es notwendig, die Exaktheit der Koregistrierung und damit die Qualitaet der Bildfusion durch kontrollierte Studien zu validieren. (orig.)

  13. MRI of injuries of the lateral ankle ligaments; MRT bei Verletzungen der lateralen und angrenzenden Baender des Sprunggelenks

    Energy Technology Data Exchange (ETDEWEB)

    Breitenseher, Martin [Landesklinikum Waldviertel Horn, Horn (Austria). Inst. fuer Radiologie und Interventionelle Radiologie

    2011-09-15

    The most frequent sport injury of the ankle is located in the lateral ankle ligaments. The diagnosis of lateral collateral ankle ligament trauma is based on patient history, clinical examination, and stress radiography, allowing a fair diagnosis for the daily routine. For the direct visualization and precise diagnosis of the lateral ankle ligaments MRI provides the best answer. MRI is used with controlled positioning of the foot, correct angulation of sequenzes, and distinct analysis of MR findings. Sinus tarsi ligaments and ligaments of the distal syndesmosis should be included to the report. In selected patients MRI allows the best evaluation of the extent of the lateral ankle ligaments. MRI is the method of choice for combined osteochondral injuries and soft tissue lesions too. (orig.)

  14. Spondylolysis in adolescents: the diagnostic value of MRI; Die Spondylolyse im Stadium der Entstehung: Diagnostischer Beitrag der MRT

    Energy Technology Data Exchange (ETDEWEB)

    Staebler, A.; Steinborn, M.; Matzko, M.; Reiser, M. [Klinikum Grosshadern, Muenchen (Germany). Inst. fuer Radiologische Diagnostik; Paulus, R.; Bosch, R. [Muenchen Univ. (Germany). Orthopaedische Klinik

    2000-01-01

    Purpose: To assess the value of MR imaging in demonstrating ongoing spondylolysis in adolescents. Methods: MRI was performed in 9 juvenile patients (3 female, 6 male aged 8-16 years; mean 12.5 y) with pain during hyperextension. In 6 patients a CT scan and in 5 a plain film was available. Results: In all patients bone marrow edema was found in the pars interarticularis and the pedicle, which was bilateral in 4 patients. In 7/9 cases the L5 vertebra was affected, in 2/9 cases spondylolysis was found in L4. In 3 cases the edema reached the middle third of the vertebral body and a tumor was suspected. In all CT scans a bilateral incomplete or complete cleft in the pars interarticularis was found. In 4/6 CT-scans a sclerosis was seen in the area of the bone marrow edema. Only in 1/5 pain films was there a suspicion for a spondylolysis, four examinations were completely normal. Conclusions: To eliminate underlying causal conditions of spondylolysis and to install specific therapy, early diagnosis is mandatory. MR imaging should be the first and only imaging modality in young patients with low back pain during and after exercise and pain with hyperextension. Bone scans and CT scans should be avoided due to irradiation, plain films usually do not reveal pathological findings in developing spondylolysis. (orig.) [German] Ziel: Darstellung der Wertigkeit der MR-Tomographie in der Diagnostik der Spondylolyse im Stadium der Entstehung. Methoden: 9 sportlich, aktive jugendliche Patienten im Alter von 8-16 Jahren (Durchschnitt 12,5 Jahre) mit Rueckenschmerzen bei der Hyperextension wurden MR-tomographisch untersucht. In 6 Faellen lag eine CT, in 5 Faellen Roentgenaufnahmen vor. Ergebnisse: Bei den 9 Jugendlichen wurden Knochenmarkoedeme in der Pars interarticularis und den Bogenwurzeln nachgewiesen, die in 4 Patienten beidseitig vorhanden waren. In 7/9 Faellen war LWK 5 betroffen, in 2/9 LWK 4. In 3 Faellen reichte das Oedem in die Wirbelkoerper, bei 2 Patienten bestand Verdacht auf einen Tumor. Alle CT-Aufnahmen zeigten beidseits inkomplette oder komplette Spaltbildungen der Pars interarticularis, in 4/6 Faellen bestand eine Sklerose in dem Bereich, der MR-tomographisch ein Knochenmarkoedem aufwies. Nur auf einer von fuenf Roentgenaufnahmen bestand der Verdacht auf eine Spondylolyse. Schlussfolgerung: Um ausloesende Ursachen beseitigen und eine spezifische Therapie durchfuehren zu koennen, ist die moeglichst fruehzeitige Diagnose einer drohenden Spondylolyse erforderlich. Die MR-Tomographie sollte die erste und einzige Untersuchungsmethode sein, wenn jugendliche Patienten nach Belastungen und bei Hyperextension ueber Rueckenschmerzen klagen. Die Skelettszintigraphie und die CT sollten wegen der Anwendung ionisierender Strahlung vermieden werden, Roentgenuebersichtsaufnahmen sind gewoehnlich ohne Befund, wenn eine Spondylolyse im Stadium der Entwicklung vorliegt. (orig.)

  15. MRI of the prostate. Recommendations on patient preparation and scanning protocol; MRT der Prostata. Empfehlungen zur Vorbereitung und Durchfuehrung

    Energy Technology Data Exchange (ETDEWEB)

    Franiel, Tobias [University Hospital Jena (Germany). Dept. of Diagnostic and Interventional Radiology; Quentin, Michael; Schimmoeller, Lars [University Hospital Duesseldorf (Germany). Dept. of Diagnostic and Interventional Radiology; Mueller-Lisse, Ullrich Gerd [Munich Univ. (Germany). Dept. of Radiology; Asbach, Patrick [Charite Universitaetsmedizin Berlin (Germany). Dept. of Radiology; Roedel, Stefan [Staedtisches Klinikum Dresden Friedrichstadt (Germany). Radiology; Willinek, Winfried [Bonn Univ. (Germany). Radiology; Hueper, Katja [Hannover Medical School (Germany). Inst. for Diagnostic and Interventional Radiology; Beyersdorff, Dirk [University Hospital Hamburg-Eppendorf, Hamburg (Germany). Dept. of Diagnostic and Interventional Radiology; Roethke, Matthias [Deutsches Krebsforschungszentrum, Heidelberg (Germany). Radiology

    2017-01-15

    The Working Group Uroradiology and Urogenital Diagnosis of the German Roentgen Society has developed uniform recommendations for the preparation and implementation of prostate MRI. In the first part detailed recommendations are given in tabular form regarding 1. anamnestic data before prostate MRI, 2. termination of examinations and preparation of examinations, 3. examination protocol and 4. MRI-guided in-bore biopsy. In the second part, the recommendations are discussed in detail and relevant background information is provided.

  16. MRT of carotid stents: influence of stent properties and sequence parameters on visualization of the carotid artery lumen

    International Nuclear Information System (INIS)

    Straube, T.; Wolf, S.; Alfke, K.; Jansen, O.; Flesser, A.; Deli, M.; Nabavi, A.

    2005-01-01

    Purpose: To evaluate MR artifacts of carotid artery stents and to optimize stent properties and sequence parameters. Material and Methods: Four carotid artery stents - Wallstent (mediloy), Precise (nitinol), ACCULINK (nitinol) and a stent prototype (nitinol) - were investigated in a flow model of the cervical vessels. The model was made of silicon tubing and a flow pump that produces realistic flow curves of the carotid artery. To investigate the effects of magnetic susceptibility and radiofrequency induced shielding artifacts, turbo spin echo and gradient echo sequences as well as CE-MRAs were measured. To improve the visualization of the stent lumen in a CE-MRA, flip angle as well as geometry and covering of the stent prototype were altered. Results: Susceptibility artifacts in stents of the carotid artery only influence the lumen visualization at the proximal and distal end of the braided mediloy stent. A change of stent coverings has no significant influence on radiofrequency artifacts, whereas a reduction in linking elements between stent segments and a change in diameter of stent struts improves visualization of the stent lumen. By increasing the flip angle in a CE-MRA, visualization of the stent lumen is possible in both mediloy and nitinol stents. Conclusion: The choice of stent material and changes in stent geometry as well as the optimization of the flip angle of the CE-MRA may reduce susceptibility and radiofrequency artifacts, rendering feasible the CE-MRA of a stented carotid artery. (orig.)

  17. Ranking of MR tomography after transsphenoidal resection of the pituitary. Retrospective comparison between endocrinology, surgery and MRT

    International Nuclear Information System (INIS)

    Siewert, B.; Kaiser, W.A.; Hochstetter, A.; Solymosi, L.; Bootsveld, K.

    1994-01-01

    Postoperative magnetic resonance images of 40 patients after transsphenoidal surgery for pituitary adenoma were evaluated retrospectively. The signal intensities of packing material and residual tumour were analysed. T 1 -weighted spin-echo sequences were obtained in coronal and sagittal views with and without intravenous injection of contrast media. Residual tumour demonstrated homogeneous or inhomogeneous signal intensity on the native scan with homogeneous or inhomogeneous enhancement. Packing material demonstrated a homogeneous signal intensity on the images obtained without injection of contrast media with a peripheral enhancement or alternate layers of low and intermediate signal intensity with alternate enhancement after injection of contrast media. In 5 of 54 examinations different results were found in MRI, endocrinology and surgery (two false negative and one false positive MRI in correlation with endocrinology; two residual tumours on MRI where surgery was supposed to be complete). Application of intravenous contrast media facilitates the interpretation of postoperative examination of the pituitary gland as well as comparison with preoperative examinations and the knowledge of the intraoperative procedure. (orig.) [de

  18. Angiogenesis of cancer of the cervix. Contrast-enhanced dynamic MRT, histological quantification of capillary density and lymph system infiltration

    International Nuclear Information System (INIS)

    Hawighorst, H.; Knoop, M.V.; Zuna, I.; Schoenberg, S.O.; Essig, M.; Hoffmann, U.; Brix, G.; Kaick, G. van; Knapstein, P.G.; Weikel, W.; Schaeffer, U.

    1998-01-01

    Purpose: It was the aim of this project to examine (i) the relationships between contrastenhanced dynamic MR imaging derived characteristics and histologic microvessel density counts - a recognized surrogate of tumor angiogenesis - from tumors in patients with primary or recurrent cancer of the uterine cervix, and (ii) to correlate these parameters with lymphatic involvement (i.e. lymphatic channels) to assess tumorbiological aggressiveness in terms of lymphatic spread. Results: Pharmacokinetic MR imaging derived parameters (A, k 21 ) showed a weak but signifikant (p 21 compared with histologic microvessel density, resulting in a significantly (p [de

  19. MRI screening before stem cell transplantation - necessary?; MRT-Untersuchung des Neurokraniums vor Stammzelltransplantation - notwendig oder ueberfluessig?

    Energy Technology Data Exchange (ETDEWEB)

    Zimmermann, U.; Mentzel, H.J.; Kaiser, W.A. [Inst. fuer Diagnostische u. Interventionelle Radiologie, Friedr.-Schiller-Univ. Jena (Germany); Wolf, J.; Fuchs, D.; Gruhn, B. [Kinderklinik, Georgius-Agricola-Krankenhaus, Zeitz (Germany); Zintl, F. [Klinik fuer Kinder- und Jugendmedizin, Friedr.-Schiller-Univ. Jena (Germany)

    2008-01-15

    Purpose: in the context of stem cell transplantation (SCT), we often observe neurological complications as a consequence of immune system suppression, conditioning therapy or prophylaxis and treatment of graft-versus-host disease. Furthermore, cerebral lesions in existence prior to transplantation can be found. The aim of this study was to evaluate the benefit of cerebral magnetic resonance imaging (MRI) prior to stem cell transplantation. Patients and method: cerebral MR examinations of 116 children and adolescents were performed before SCT. Patients ranged in age from 1.1 to 21.4 years (mean 12.6 years). All MR images were obtained by a 1.5 T System. The predefined short protocol included an axial T1-weighted SE sequence and a coronary T2-weighted TSE sequence. We evaluated existing cerebral lesions, the diameter of the ventricular system, and the paranasal sinuses. In the case of pathological findings, the short examination protocol was expanded. Results: in 5 of 116 children (4.3%) we observed prior to SCT findings requiring immediate treatment although the patients did not show any clinical symptoms (1 x aspergilloma, 1 x hemorrhage of vascular anomaly). An increased risk of bleeding caused by cavernoma or another vascular anomaly without hemorrhage also had to be taken into account. 32 of 116 patients (37.1%) showed atrophic lesions. In 42 children (36.2%), we observed affections of the paranasal sinuses. (orig.)

  20. Clinical neuroanatomy - cranial MRI and CT. 4. rev. and enl. ed.; Klinische Neuroanatomie - kranielle MRT und CT

    Energy Technology Data Exchange (ETDEWEB)

    Lanfermann, Heinrich; Raab, Peter [Medizinische Hochschule Hannover (MHH) (Germany). Inst. fuer Diagnostische und Interventionelle Neuroradiologie; Kretschmann, Hans-Joachim; Weinrich, Wolfgang

    2015-07-01

    The book on clinical neuroanatomy - cranial MRI and CT covers the following issues: layered imaging diagnostics and reference structures; frontal layer, sagittal layers, transverse layers, brainstem, skull topography and the intracranial spaces and structures, facial skull topography, head-neck topography; neurofunctional systems, neurotransmitter and neuromodulators, surveillance material and techniques.

  1. Transient osteoporosis or femoral head necrosis Early diagnosis via MRI. Transitorische Osteoporose oder Femurkopfnekrose Fruehdiagnose mit der MRT

    Energy Technology Data Exchange (ETDEWEB)

    Higer, H P; Grimm, J; Pedrosa, P; Apel, R; Bandilla, K [Stiftung Deutsche Klinik fuer Diagnostik, Wiesbaden (Germany, F.R.). Fachbereich Kernspintomographie; Stiftung Deutsche Klinik fuer Diagnostik, Wiesbaden (Germany, F.R.). Fachbereich Rheumatologie; Mainz Univ. (Germany, F.R.). Orthopaedische Klinik und Poliklinik)

    1989-04-01

    Transient osteoporosis of the hip is a syndrome that does not seem to be widely known; this is also true for its radiological appearance. It is often mistaken for avascular necrosis of the femoral head, metastatic or inflammatory disease. These differential diagnoses lead to more or less invasive procedures, although transient osteoporosis does not require more than immobilisation for complete remission. MRI was done in 38 patients with acute hip pain, 13 had femoral head necrosis and 8 transient osteoporosis. Follow-up studies via MRI in patients with transient osteoporosis revealed 3 stages (diffuse, focal, residual) during the clinical course of which stage II is similar to femoral head necrosis but always without the typical sclerotic rim. (orig.).

  2. Environmental behaviour und ecotoxiology of gadolinium-containing MRT contrast media; Umweltverhalten und Oekotoxikologie von gadoliniumhaltigen Magnetresonanztomographie-Kontrastmitteln

    Energy Technology Data Exchange (ETDEWEB)

    Neubert, Claudia

    2008-07-08

    Magnetic resonance imaging (MRI) is an essential tool in noninvasive diagnostics. In order to improve the sensitivity and specificity of diagnoses, several contrast enhancing agents have been developed in the last few decades by various pharmaceutical manufacturers. Gadolinium (Gd), a lanthanide, is the most widely used metal in MRI contrast agents. Its ion has paramagnetic properties (seven unpaired electrons) and a very long electronic relaxation time. Due to the toxicity of free Gd, clinical use is only possible in a complexed form. Commonly used chelating agents are polyamino-polycarboxylic ligands such as DTPA. Due to the exceptional stability of these highly hydrophilic chelates and the lack of human metabolism, the contrast media are quantitatively excreted unchanged after the administration, and are subsequently emitted into the aquatic environment. Several studies have shown notable increases in Gd concentrations in surface or groundwaters receiving sewage effluents, an observation which has been termed ''Gd anomaly''. The Gd anomaly results from the use of MRI contrast agents for which the most significant entry route is the effluent from wastewater treatment works. Relatively little information on the aquatic toxicity of Gd or Gd-chelates has been published up to 2006. Therefore, in a first step, the acute aquatic toxicity of several MRI contrast agents was investigated in fish, daphnia and algae at high concentrations. Furthermore, chronic toxicity tests on fish and daphnia were conducted. The results showed that contrast enhancing agents containing Gd have no toxic effects on the tested organisms at concentrations being of relevance to the environment. At high concentrations growth inhibition of green algae was observed. The environmental fate and the biological degradation of the contrast media was studied in a model wastewater treatment plant and in aquatic sediment systems. The test compounds were neither biodegradable in the treatment plants nor in the sediment. Additionally, the contrast agents did not accumulate in the sediment. Flocculation with FeCl{sub 3} caused a loss of stability of the Gd-complexes. In a study on the bioaccumulation of the contrast agents marginal concentrations of Gd were detected in fish. To further investigate the toxic potential and the environmental fate of free Gd, studies on the aquatic toxicity, the bioaccumulation potential and the distribution in aquatic sediment systems were performed with GdCl{sub 3} x 6 H{sub 2}O and GdCl{sub 3} x H{sub 2}O, respectively. Gd caused adverse effects in daphnia and algae but was not toxic to fish. Accumulation was observed in fish and sediment. Furthermore, the little water solubility of the lanthanide in natural water was confirmed. (orig.)

  3. MR imaging of the knee following cruciate ligament reconstruction and meniscal surgery; MRT des Kniegelenks nach Kreuzband- und Meniskusoperationen

    Energy Technology Data Exchange (ETDEWEB)

    Woertler, K. [Technische Univ. Muenchen, Klinikum rechts der Isar (Germany). Inst. fuer Roentgendiagnostik

    2009-03-15

    Due to the increasing number of surgical procedures performed on the knee, MR imaging of the postoperative knee has gained more and more importance. For the evaluation of anterior cruciate ligament grafts and postoperative menisci, basic knowledge of surgical techniques is essential in order to differentiate normal postoperative findings from transplant failure, retears, and complications. This article reviews technical aspects of MR imaging following knee surgery, basic principles of operative techniques for anterior cruciate ligament reconstruction and therapy of meniscal tears, normal postoperative findings, MR imaging criteria for recurrent lesions, and findings with typical complications. (orig.)

  4. Cardiac magnetic resonance imaging in patients with congenital heart disease; Kardiale MRT bei Patienten mit angeborenen Herzfehlern

    Energy Technology Data Exchange (ETDEWEB)

    Kreitner, Karl-Friedrich [Mainz Univ. Universitaetsmedizin Mainz (Germany). Klinik und Poliklinik fuer Diagnostische und Interventionelle Radiologie; Kaufmann, Lilly [Mainz Univ. (Germany); Sorantin, Erich [Univ.-Klinik fuer Radiologie, Graz (Austria). Klinische Abt. fuer Kinderradiologie

    2015-06-15

    The prevalence of congenital heart disease (CHD) is around 10 per 1000 live births in Germany. More than 90 % of these patients will survive into adulthood due to improvements in therapy. The classification of CHD may be based according to the anatomic structures involved, to the presence of an intracardiac shunt, the presence of a cyanosis and the intensity of therapy and complexity of the disease. Nearly half of all patients with CHD suffer from an intracardiac shunt, whereas complex cases such as patients with a tetralogy of Fallot or transposition of the great arteries are much more rare. Cardiac magnetic resonance imaging plays an important role in the work-up and follow-up of patients with CHD, especially after infancy and childhood. Depending on the abnormality in question, a multiparametric examination protocol is mandatory. Knowledge of operative procedures and findings of other imaging modalities help to optimize examination and time needed for it.

  5. MRT of experimental liver abscesses - comparison of a new blood pool contrast agent with gadolinium-DTPA

    International Nuclear Information System (INIS)

    Dick, A.; Adam, G.; Spuentrup, E.; Prescher, A.; Muehler, A.; Guenther, R.W.

    1996-01-01

    Purpose: In an experimental pyogenic liver abscess model, the signal intensities were compared intraindividually and interindividually after the application of a new blood pool contrast agent, 24-gadolinium-DTPA (diethylenetriamine-pentaacetic acid) cascade polymer, and after the application of gadopentetate dimeglumine. Methods: In 20 rabbits with experimentally induced liver abscesses, the relative signal intensities of the liver, abscess centre, abscess wall and portal vein were assessed before and between 30 seconds and 60 minutes after injection of a 25 μmol/kg dose of gadolinium polymer and of 100 μmol/kg of gadolinium-DTPA, respectively. Measurements were performed at 1.5 Tesla, using a head coil and a Flash-2-D sequence. Results: The interindividual comparison (unpaired T-test, p [de

  6. Early signs of degenerative arthritis of the hip by MRI. Fruehe Zeichen der Hueftgelenkarthrose in der MRT

    Energy Technology Data Exchange (ETDEWEB)

    Bongartz, G.; Mueller-Miny, H.; Peters, P.E. (Muenster Univ. (Germany, F.R.). Inst. fuer Klinische Radiologie)

    1989-10-01

    The hips of 8 young volunteers were investigated with high resolution MRI. The purpose of this study was to establish an imaging protocol to visualize hyaline cartilage, synovial fluid, and subchondral bone with optimized contrast. Spin Echo (SE) and Gradient Echo (GE) sequences were compared. FISP with a flip angle of 70{sup 0} was superior to the other techniques. The same sequences were applied on 45 volunteers aged 65-93 years. Early signs of degenerative arthritis of the hip were demonstrated as thinning, variable signal intensities within the cartilage layer, and cartilage loss. MRI of the hip may be a useful tool for the detection of early degenerative cartilage damage which cannot be documented with conventional X-rays. (orig.).

  7. One-year follow-up of neuropsychology, MRI, rCBF and glucose metabolism (rMRGlu) in cerebral microangiopathy

    Energy Technology Data Exchange (ETDEWEB)

    Sabri, O.; Hellwig, D.; Schreckenberger, M.; Kaiser, H.-J.; Wagenknecht, G.; Setani, K.; Reinartz, P.; Zimny, M.; Buell, U. [Department of Nuclear Medicine, Technische Univ. Aachen (Germany); Schneider, R. [Department of Neurology, Technische Univ. Aachen (Germany); Mull, M. [Department of Neuroradiology, Technische Univ. Aachen (Germany); Ringelstein, E.-B. [Department of Neurology, Muenster Univ. (Germany)

    2000-07-01

    Background: MRI shows lacunar infarctions (LI), deep white matter lesions (DWML) and atrophy in cerebral microangiopathy, which is said to lead to vascular dementia. In a first trial series on 57 patients with confirmed pure cerebral microangiopathy (without concomitant macroangiopathy), neuropsychological impairment and (where present) brain atrophy correlated with decreased rCBF and rMRGlu. LI and DWML did not correlate with either neuropsychological impairment or decreased rCBF/rMRGlu. This study was done one year later to detect changes in any of the study parameters. Methods: 26 patients were re-examined for rCBF, rMRGlu, LI, DWML, atrophy and neuropsychological performance (7 cognitive, 3 mnestic, 4 attentiveness tests). Using a special head holder for exact repositioning, rCBF (SPECT) and rMRGlu (PET) were measured and imaged slice by slice. White matter/cortex were quantified using MRI-defined ROIs. Results: After one year the patients did not show significant decreases in rCBF or rMRGlu either in cortex or in white matter (p>0.05), nor did any patient show LI, DWML or atrophy changes on MRI. There were no significant neuropsychological decreases (p>0.05). (orig.) [German] Ziel: In der MRT zeigen sich bei zerebraler Mikroangiopathie (ZMA) lakunaere Infarkte (LI), Deep White Matter Lesions (DWML) und Atrophie (Atr). Die sogenannte vaskulaere Demenz wurde dabei hauptsaechlich auf die Laesionen der weissen Substanz zurueckgefuehrt. In einer ersten Untersuchungsreihe waren bei 57 Patienten mit gesicherter ZMA nur neuropsychologische Defizite (Nps) und, falls vorhanden, Atr als Grundlage fuer erniedrigte rCBF/rMRGlu-Werte zu eruieren, jedoch nicht LI/DWML. Es sollte geklaert werden, ob sich im Verlauf der Erkrankung nach einem Jahr Veraenderungen dieser Parameter ergeben. Methode: 26 Patienten wurden nach einem Jahr erneut neuropsychologisch untersucht (7 kognitive, 3 mnestrische, 4 Aufmerksamkeitstests). Mittels eines speziellen Kopfhalterungssystems wurden in

  8. Air-electron stream interactions during magnetic resonance IGRT. Skin irradiation outside the treatment field during accelerated partial breast irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jong Min [Seoul National University Hospital, Department of Radiation Oncology, Seoul (Korea, Republic of); Seoul National University Hospital, Biomedical Research Institute, Seoul (Korea, Republic of); Seoul National University Medical Research Center, Institute of Radiation Medicine, Seoul (Korea, Republic of); Advanced Institutes of Convergence Technology, Robotics Research Laboratory for Extreme Environments, Suwon (Korea, Republic of); Shin, Kyung Hwan; Wu, Hong-Gyun [Seoul National University Hospital, Department of Radiation Oncology, Seoul (Korea, Republic of); Seoul National University Hospital, Biomedical Research Institute, Seoul (Korea, Republic of); Seoul National University Medical Research Center, Institute of Radiation Medicine, Seoul (Korea, Republic of); Seoul National University College of Medicine, Department of Radiation Oncology, Seoul (Korea, Republic of); Kim, Jung-in; Park, So-Yeon; Kim, Jin Ho [Seoul National University Hospital, Department of Radiation Oncology, Seoul (Korea, Republic of); Seoul National University Hospital, Biomedical Research Institute, Seoul (Korea, Republic of); Seoul National University Medical Research Center, Institute of Radiation Medicine, Seoul (Korea, Republic of); Jeon, Seung Hyuck [Seoul National University Hospital, Department of Radiation Oncology, Seoul (Korea, Republic of); Choi, Noorie [Seoul National University College of Medicine, Department of Radiation Oncology, Seoul (Korea, Republic of)

    2018-01-15

    ein Elektronenstrahl ausserhalb der Therapiefelder entstehen. In dieser Studie wurde fuer akzelerierte Teilbrustbestrahlungen (APBI) diese Strahlung abgeschirmt und naeher untersucht. Fuer diese Studie wurden prospektiv 20 Patientinnen ausgewaehlt, die eine APBI mit einer MRT-gefuehrten Strahlentherapie (MR-IGRT) erhielten. Die Bestrahlung erfolgte mit einem Tri-Kobalt-System, das mit einem Magnetresonanztomographen kombiniert war (ViewRay). Es wurden jeweils 10 Fraktionen mit einer Einzeldosis von 3,85 Gy und der resultierenden Gesamtdosis von 38,5 Gy appliziert. Zur Reduktion der Hautdosis wurden pro Patientin 2 unterschiedliche Therapieplaene fuer jeweils 5 Fraktionen mit unterschiedlichen Tragarmwinkeln eingesetzt. Zur Abschirmung des unerwuenschten Elektronenstrahls ausserhalb der Strahlenfelder wurde ein 1 cm starker Bolus vor dem Kiefer sowie vor der ipsilateralen Schulter und dem Arm der Patientin positioniert. Vor dem Bolusmaterial (Richtung Brust) und hinter dem Bolusmaterial (Richtung Kopf) wurden EBT3-Radiochromroentgenfilme befestigt, um die ein- und austretende Dosis zu messen. Die Abhaengigkeiten der Messwerte von der Lokalisation des bestrahlten Tumors, der Bestrahlungszeit und der Tumorgroesse wurden untersucht. Fuer jeweils eine Strahlenfraktion wurden auf den Roentgenfilmen vor dem Bolusmaterial (Richtung Brust) die von den einzelnen Isodosen eingeschlossenen Flaechen vermessen: die 14 %-Isodosis (0,54 Gy) umschloss im Mittel eine Flaeche von 3,6 cm{sup 2}, die 12 %-Isodosis (0,46 Gy) im Mittel 10,4 cm{sup 2} und die 10 %-Isodosis (0,39 Gy) im Mittel 21,4 cm{sup 2}. Die Roentgenfilme hinter dem Bolusmaterial zeigten hingegen keine signifikante Dosisbelastung an. Statistisch signifikante, aber nur geringe Korrelationen wurden zwischen der Dosisbelastung und den Behandlungszeiten beobachtet. Werden Brustkrebspatientinnen mit einem MRT-gefuehrten Tri-Kobalt-Bestrahlungsgeraet behandelt, kann durch eine Wechselwirkung von Strahlenquelle und

  9. Measurement of perfusion using the first-pass dynamic susceptibility-weighted contrast-enhanced (DSC) MRI in neurooncology. Physical basics and clinical applications; Perfusionsmessung mit der T2*-Kontrastmitteldynamik in der Neuroonkologie. Physikalische Grundlagen und klinische Anwendungen

    Energy Technology Data Exchange (ETDEWEB)

    Weber, M.-A.; Giesel, F.L.; Kauczor, H.-U.; Essig, M. [Deutsches Krebsforschungszentrum (DKFZ) Heidelberg (Germany). Abteilung Radiologie; Risse, F.; Schad, L.R. [Deutsches Krebsforschungszentrum (DKFZ) Heidelberg (Germany). Abteilung Medizinische Physik in der Radiologie

    2005-07-01

    Perfusion imaging in the central nervous system (CNS) is mostly performed using the first-pass dynamic susceptibility-weighted contrast-enhanced (DSC) MRI. The first-pass of a contrast bolus in brain tissue is monitored by a series of T2*-weighted MR images. The susceptibility effect of the paramagnetic contrast agent leads to a signal loss that can be converted, using the principles of the indicator dilution theory, into an increase of the contrast agent concentration. From these data, parameter maps of cerebral blood volume (CBV) and flow (CBF) can be derived. Regional CBF and CBV values can be obtained by region-of-interest analysis. This review article describes physical basics of DSC MRI and summarizes the literature of DSC MRI in neurooncological issues. Studies, all with relatively limited patient numbers, report that DSC MRI is useful in the preoperative diagnosis of gliomas, CNS-lymphomas, and solitary metastases, as well as in the differentiation of these neoplastic lesions from infections and tumor-like manifestations of demyelinating disease. Additionally, DSC MRI is suitable for determining glioma grade and regions of active tumor growth which should be the target of stereotactic biopsy. After therapy, DSC MRI helps better assessing the tumor response to therapy, residual tumor after therapy, and possible treatment failure and therapy-related complications, such as radiation necrosis. The preliminary results show that DSC MRI is a diagnostic tool depicting regional variations in microvasculature of normal and diseased brains. (orig.) [German] Die MRT-Perfusionsmessungen im Zentralnervensystem (ZNS) werden derzeit hauptsaechlich mit der kontrastmittelverstaerkten T2*-Dynamik durchgefuehrt, die die Passage eines schnellen Kontrastmittelbolus mit einer Serie von T2*-gewichteten MRT-Aufnahmen verfolgt und charakterisiert. Dabei wird der Signalabfall, bedingt durch den Suszeptibilitaetseffekt des paramagnetischen Kontrastmittels, mittels geeigneter

  10. Radiological diagnosis of Klatskin's tumour; Radiologische Diagnostik von Klatskin-Tumoren

    Energy Technology Data Exchange (ETDEWEB)

    Pauls, S.; Juchems, M.S.; Brambs, H.-J. [Universitaetsklinikum Ulm (Germany). Abteilung Diagnostische Radiologie

    2005-11-01

    Patients with Klatskin's tumour present clinically unspecific symptoms such as painless jaundice and cholangitic discomfort. The only curative treatment is R0 resection of the tumour. To allow stage-specific therapy, accurate tumour staging is indispensable, the first step of which is abdominal sonography. If there is a suspect finding, cross-sectional imaging techniques like MRI or MDR-CT are used to clarify or stage the lesion, respectively. To estimate resectability, MRI together with MRC and MRI angiography are superior to MDR-CT. Biopsy using ERC is required before starting any specific treatment. If therapeutically relevant peritoneal carcinosis is clinically suspected although not radiologically confirmed, PET should also be performed. The value of PET/CT has to be evaluated in further studies. For optimal treatment, close cooperation between clinicians and radiologists is necessary. (orig.) [German] Patienten mit Klatskin-Tumoren werden klinisch durch unspezifische Symptome wie z. B. schmerzloser Ikterus oder cholangitische Beschwerden auffaellig. Eine R0-Resektion ist der einzige kurative Therapieansatz. Um eine stadiengerechte Therapie zu ermoeglichen, muss ein moeglichst exaktes Tumorstaging erfolgen. Primaer kommt die abdominelle Sonographie zum Einsatz. Zur Abklaerung eines unklaren Sonographiebefundes sowie zum Staging eines suspizierten Tumors werden Schnittbildverfahren MRT und MDR-CT benoetigt. Zur Beurteilung der lokalen Tumorresektabilitaet ist die MRT in Zusammenschau mit der MRC sowie MR-Angiographie der MDR-CT ueberlegen. Vor Einleitung einer Therapie sollte auf jeden Fall die Verdachtsdiagnose eines Klatskin-Tumors bioptisch mittels ERC gesichert werden. Wird klinisch trotz negativem Nachweis einer Peritonealkarzinose eine solche suspiziert, sollte bei Therapierelevanz (z. B. bei ansonsten fehlendem Nachweis einer Fernmetastasierung) eine PET ergaenzend durchgefuehrt werden. Der zukuenftige Stellenwert der PET/CT muss in weiteren Studien

  11. Characterization of oxidation protection coatings for high temperature applications by means of nanoindentation and scanning electron microscopy methods; Charakterisierung von Oxidationsschutzschichten fuer Hochtemperaturanwendungen mittels Nanoindentierung und rasterelektronenmikroskopischen Methoden

    Energy Technology Data Exchange (ETDEWEB)

    Webler, R.; Neumeier, S.; Goeken, M. [Erlangen-Nuernberg Univ., Erlangen (Germany). Lehrstuhl fuer Allgemeine Werkstoffeigenschaften

    2014-10-01

    Oxidation protection coatings are required for thermally highly stressed components such as turbine blades in aircraft engines. Cyclic oxidation experiments were performed on a NiCoCrAlY protective coating of a nickel-based superalloy and hardness and modulus of elasticity (mechanical properties) were determined by nanoindentation before and after the experiments. Microstructure and chemical composition were characterized by means of scanning electron microscopy. Here, the focus is on the phase identification by combining electron backscatter diffraction and energy dispersive X-ray spectroscopy. Findings indicate that the chemical composition strongly influences the mechanical properties.

  12. Aspects of industrial production of solid electrolyte fuel cells (SOFC) by thermal spraying technology; Aspekte industrieller Fertigung von Festelektrolyt-Brennstoffzellen (SOFC) mittels thermischer Beschichtungsverfahren

    Energy Technology Data Exchange (ETDEWEB)

    Weckmann, Hannes

    2010-07-01

    The present thesis deals with measures to optimize the large-volume production of Solid Oxide Fuel Cells (SOFC) based on thermal spraying technology. Based on the well-established Vacuum Plasma Spraying (VPS) at DLR the potential of alternative thermal spraying techniques as well as alternative base materials was investigated in order to deposit SOFC-anode, electrolyte and insulating layers. Production costs, reproducibility and long-term stability of the production process as well as the fuel cell performance were major target criteria. Depending on the parameter set applied when using the cost efficient Atmospheric Plasma Spraying (APS) in combination with Nickel-Graphite as base material a significant improvement of gas permeability and electrical conductivity was achieved in comparison to the VPS sprayed reference anode. The power density of a fuel cell with an APS-Nickel-Graphite anode (184 mW/cm{sup 2}) was slightly better than the performance with a VPS reference anode (159 mW/cm{sup 2}). In comparison to the VPS process, ceramic electrolyte layers of fully stabilized Zirconia (YSZ) with significantly higher gas tightness could be demonstrated when high energy processes such as Low Pressure Plasma Spraying (LPPS). Thin-film Low Pressure Plasma Spraying (LPPS-Thin-film) and High Velocity Oxy Fuel Spraying (HVOF) were applied. The power density of a fuel cell equipped with an HVOF electrolyte was significantly improved to 234 mW/cm{sup 2} as compared to 187 mW/cm{sup 2} with the VPS sprayed reference cell. Further improvement of the power density was achieved with an LPPS-electrolyte (273 mW/cm{sup 2}). HVOF and VPS sprayed layers of pure Spinel in composite with metallic active braze (equivalent to the sealing between individual layers in the fuel cell stack) could exceed the demanded charge transfer resistance of >1 k{omega}cm{sup 2} at 800 C operating temperature only in few cases. When blended base powder of Spinel and Magnesia in combination with the VPS was applied significantly higher charge transfer resistance of up to 1,7 M{omega}cm{sup 2} could be demonstrated at layer thicknesses between 20 {mu}m and 117 {mu}m. In the further course of the thesis an online controller was developed for the VPS process based on insitu process diagnostic systems in order to reproducibly produce thermal sprayed functional layers. In pretests the process diagnostic system Accuraspray appeared to be cable of identifying changes in the process by detecting particle properties in the spray torch. In order to serve as a knowledge base for the controller the plasma spraying process was successfully modelled as correlation between machine parameters, spray torch- und layer properties by using artificial neural networks (ANN). The ability for the generalization as well as the accuracy of the model was improved further by measures such as active learning (additional experiments at poorly represented regions) and the combination of several models with different network architectures as an ensemble (mixture of experts). Based on the artificial neural network model, an online process controller was developed, which manipulates major process parameters in case of a deviation in order to get back to the initial state. The ability of the prototype controller could be demonstrated successfully in most cases. (orig.)

  13. Growth of gallium nitride based devices on silicon(001) substrates by metalorganic vapor phase epitaxy; Wachstum von Galliumnitrid-basierten Bauelementen auf Silizium(001)-Substraten mittels metallorganischer Gasphasenepitaxie

    Energy Technology Data Exchange (ETDEWEB)

    Reiher, Fabian

    2009-02-25

    The main topic of this thesis is to investigate GaN-based layer systems grown by metalorganic vapor phase epitaxy on Si(001) substrates. A temperature shift up to 45 K is measured for a complete device structure on a 2-inch silicon substrate. By using a 40 nm thin LT-AlN-seed layer (680 C), the GaN crystallites on Si(001) substrates are almost oriented with their GaN(10 anti 12)-planes parallel to the Si(001)-plane. A four-fold azimuthal symmetry occurs for these layers, with the GaN[10 anti 11]-direction is aligned parallel to one of the four equivalent left angle 110 right angle -directions, respectively. However, a mono-crystalline and fully coalesced GaN-layer with this crystallographic orientation could not yet been obtained. If a deposition temperature of more than 1100 C is used for the AlN-seed layer, solely the GaN[0001]- growth direction of crystallites occurs in the main GaN layer on Si(001) substrates. These c-axis oriented GaN columns feature two opposite azimuthal alignments that are rotated by 90 with respect to each other and with GaN[11 anti 20] parallel Si[110] and GaN[10 anti 10] parallel Si[110], respectively. By using 4 off-oriented substrates towards the Si[110]-direction, one certain azimuthal texture component can be selected. The critical value of the miscut angle corresponds to theoretical calculations predicting the occurrence of atomic double steps on the Si(001) surface. The achieved crystallographic quality of the GaN layers on Si(001) is characterized by having a tilt of FWHM=0.27 and a twist of FWHM=0.8 of the crystallites, determined by X-ray diffraction. A completely crack-free, up to 2.5 {mu}m thick, and mono-crystalline GaN-template can be realized on Si(001), integrating 4 or 5 LT-AlN-interlayers in the GaN buffer structure. Based on this structure, the first successful implementation of an (InGaN/GaN)-LED on Si(001) is achieved. Furthermore, the possible fabrication of GaN-based FET-structures is demonstrated with a fully processed and operating device on Si(001). Moreover, the developed approach for the MOVPE growth of GaN on Si(001) is successfully adapted to large area 150 mm Si(001) substrates, proving the possible scalability to industrial circuits. (orig.)

  14. Firedamp processing in a membrane system in the 'Alsbachschacht' mine; 'Aufbereitung von Grubengas mittels Membrananlage am Alsbachschacht'

    Energy Technology Data Exchange (ETDEWEB)

    Berwanger, R.; Dengel, A. [Evonik New Energies GmbH, Saarbruecken (Germany); Brinkmann, T. [GKSS-Forschungszentrum Geesthacht GmbH, Geesthacht (Germany); Clemens, W. [OTS Ingenieurgesellschaft mbH, Puettlingen (Germany); Hoting, B. [Borsig Membrane Technology GmbH, Berlin (Germany)

    2009-07-01

    For safe and environment-friendly operation of refrigerators and cryotechnical facilities, knowledge of the permeation characteristics of the elastomers and fibre-reinforced materials used is of utmost importance. While elastomers are used primarily as sealing materials, fibre-reinforced materials are used increasingly in containers for supercooled liquids (LN2, LH2, LHe). Measuring apparatuses and methods of measurement were developed at Institut fuer Luft- und Kaeltetechnik Dresden (Institute of Ventilation and Refrigeration Engineering) that provide quantitative information on the permeation characteristics as a function of temperature. (orig.)

  15. Hydraulic balance by means of electromotoric HKV drives for dynamic load profiles; Hydraulischer Abgleich mittels elektromotorischer HKV-Antriebe fuer dynamische Lastprofile

    Energy Technology Data Exchange (ETDEWEB)

    Szendrei, Danny [Westsaechsische Hochschule Zwickau (Germany)

    2010-07-01

    To date, measures and concepts for saving energy become more and more important. The development of prices for conventional energy sources forces public and private households and businesses to changes in consumer behaviour and purchasing behaviour. Due to the structural infrastructure, the housing construction in communes strongly is affected by these developments. Nearly 35 % of the total energy demand in Europe account for heating of buildings generally. The most common type of heating system for heating of residential buildings is the central hot water heating in the two-tube version. It is assumed that nearly 90 % of the operated plants have a hydraulic unbalance. Additionally, balanced heating systems fulfil the desired efficiency only under certain, structural design conditions. The integration of the control of heating systems in the smart home infrastructure or KNX infrastructure enables a building-independent, tunable heat supply between buildings and consumption acquisition. The hydraulic system loads can be optimized simultaneously via the direct access to the control value. Thus, a homogeneous mass distribution over the plant can be guaranteed which is derived from the dynamic needs of the system users. These heat loads are calculated by the KNX system and the application of HeatingControl.

  16. Development of a high performance drivage by 'Bolter-Miner' technology; Entwicklung eines Hochleistungsvortriebs mittels Bolter-Miner-Technik

    Energy Technology Data Exchange (ETDEWEB)

    Vierhaus, R. [Deutsche Steinkohle AG, Herne (Germany); Terbach, G. [Bergwerk Auguste Victoria/Blumenthal, Marl (Germany)

    2002-09-05

    The introduction of the bolter miner technic at Auguste Victoria/Blumenthal mine will be shown. This benchmarking project coming from the australian mining industry was put into practice for the first time in the german hard coal industry. It was rapidly turned out, that the demands of the roadways concerning the number and length of the required bolts and as well as the safety aspects are very different to the visited headings in Australia. The way starting with an average drivage rate of 5 m/d day in the first project up to today's performance level of 16 m/d in the third project is represented. From a view on the totality it is described, what kind of demands are required by the logistics, the infrastructure, the organization of the operation, the ergonomics and last but not least the motivation of the crew to achieve a high performance of 22 m/d. (orig.) [German] Im Beitrag wird die Einfuehrung der Bolter-Miner-Technik auf dem Bergwerk Auguste Victoria/Blumenthal aufgezeigt. Dieses Benchmarking-Projekt aus dem australischen Bergbau wurde erstmalig im deutschen Steinkohlenbergbau umgesetzt. Es zeigte sich sehr schnell, dass die Anforderungen der Strecken in bezug auf die Anzahl und Laenge der einzubauenden Anker sowie die sicherheitlichen Aspekte zu den besuchten Vortrieben in Australien stark differierten. Zudem wird der Weg von durchschnittlich 5 m/d im ersten Projekt bis zu den heutigen Leistungsdaten von 16 m/d im dritten Projekt dargestellt. In einer ganzheitlichen Betrachtung wird aufgezeigt, welche Anforderungen in der Logistik, in der Infrastruktur, in der Betriebsorganisation, in der Ergonomie und in der Motivation der Mannschaft notwendig waren, Spitzenleistungen von 22 m/d zu erreichen. (orig.)

  17. Characterization of partitioning relevant lanthanide and actinide complexes by NMR spectroscopy; Charakterisierung von partitioningrelevanten Lanthaniden- und Actinidenkomplexen mittels NMR-Spektroskopie

    Energy Technology Data Exchange (ETDEWEB)

    Adam, Christian

    2016-01-15

    In the present work the interaction of N-donor ligands, such as 2,6-Bis(5,6-dipropyl-1,2,4-triazin-3-yl)pyridine (nPrBTP) and 2,6-Bis(5-(2,2-dimethylpropyl)1H-pyrazol)-3-yl-pyridine (C5-BPP), with trivalent lanthanide and actinide ions was studied. Ligands of this type show a high selectivity for the separation of trivalent actinide ions over lanthanides from nitric acid solutions. However, the reason for this selectivity, which is crucial for future partitioning and transmutation strategies for radioactive wastes, is still unknown. So far, the selectivity of some N-donor ligands is supposed to be an effect of an increased covalency in the actinide-ligand bond, compared to the lanthanide compounds. NMR spectroscopy on paramagnetic metal complexes is an excellent tool for the elucidation of bonding modes. The overall paramagnetic chemical shift consists of two contributions, the Fermi Contact Shift (FCS), due to electron spin delocalisation through covalent bonds, and the Pseudo Contact Shift (PCS), which describes the dipolar coupling of the electron magnetic moment and the nuclear spin. By assessing the FCS share in the paramagnetic shift, the degree of covalency in the metal-ligand bond can be gauged. Several methods to discriminate FCS and PCS have been used on the data of the nPrBTP- and C5-BPP-complexes and were evaluated regarding their applicability on lanthanide and actinide complexes with N-donor ligands. The study comprised the synthesis of all Ln(III) complexes with the exceptions of Pm(III) and Gd(III) as well as the Am(III) complex as a representative of the actinide series with both ligands. All complexes were fully characterised ({sup 1}H, {sup 13}C and {sup 15}N spectra) using NMR spectroscopy. By isotope enrichment with the NMR-active {sup 15}N in positions 8 and 9 in both ligands, resonance signals of these nitrogen atoms were detected for all complexes. The Bleaneymethod relies on different temperature dependencies for FCS (T{sup -1}) and PCS (T{sup -2}) that occur upon description of the paramagnetic shift as a series of temperature-dependent terms. This method was applied to all nuclei in both complex series. Especially for the protons, and to a slightly lesser degree also for the heteronuclei, calculated FCS values appear unrealistically high, as they dominate the paramagnetic chemical shift. In some cases, the Bleaney method showed that spin polarisation is an important pathway for the transfer of electron spin density between metal ion and ligand. The Reilley method is a temperature-independent and well established procedure. Two theoretically determined values, the spin expectation value in z-direction of the lanthanide ion, left angle S{sub z} right angle {sub Ln}, and the so-called Bleaney parameter C{sub Ln}, are used for the calculation of FCS and PCS. For this method, there are two sets of parameters for calculations and two variants of graphical analysis available. For all variants, the Reilley method yielded plausible values for FCS and PCS. Furthermore, the behaviour of the magnetic anisotropy of the lanthanide ions was depicted correctly. An important result is that the metal-nitrogen bonding has a notable share of covalency even in the lanthanide complexes. For the protons the PCS is the dominant interaction. The carbon atoms of the aromatic rings exhibit an influence of the PCS, while the FCS is the dominant contribution and spin polarisation patterns can be identified. Without reliable methods for the exact determination of the FCS in Am(III) complexes, the quantification of the covalency in the metal-ligand bond is not possible. Nevertheless, we can qualitatively asses that there is a strong influence of effects relying on covalent bonds in the Am(III) complexes. The coordinating nitrogen atoms show a strong, localised shift of the resonance signals of more than 250 ppm upfield compared to the lanthanide complexes. This is attributed to a strong spin-orbit interaction, which is transmitted to the nitrogen atom. Like the FCS, this mechanism roots on the presence of a significant covalency in the metal-ligand bond. Therefore, this is the first spectroscopic proof of covalency in an actinide-ligand bond. With the analysis of {sup 15}N chemical shifts in Ln(III) and Am(III) complexes, new data for directly coordinating heteronuclei in organic N-donor ligands were obtained. These data are an important prerequisite for a critical assessment of the present NMR theory for paramagnetic substances and will also be useful as a benchmark for quantum chemical calculations. They are a valuable contribution to a better understanding of bonding and extraction behaviour of N-donor ligands on a molecular scale. This newly obtained knowledge is indispensable for the design of improved extraction ligands and the optimisation of extraction processes.

  18. Investigation of environmental samples from Fukushima with respect to uranium and plutonium by AMS; Untersuchung von Umweltproben aus Fukushima in Bezug auf Plutonium und Uran mittels AMS

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, Stephanie

    2017-02-01

    In March 2011, the nuclear power plant Fukushima Dai-ichi was seriously damaged by a tsunami caused by an earthquake. During the accident large quantities of radionuclides, mainly of the volatile elements cesium and iodine, were released to the environment. In small amounts refractory elements such as plutonium and uranium have also been released. Plutonium and the uraniumisotope {sup 236}U have primarily been delivered by human activities in the environment. Large amounts were released during the atmospheric nuclear weapons tests. Additional sources are accidents in nuclear facilities, like Chernobyl. Every source has its own characteristic isotopic composition. It is therefore possible to determine the origin of the contamination by measuring the isotopic ratios of {sup 240}Pu/{sup 239}Pu and {sup 236}U/{sup 238}U. These ratios can be determined by using accelerator mass spectrometry. Due to its high sensitivity, it is possible to measure even small amounts of plutonium and especially of {sup 236}U. These measurements were performed using the compact 500 kV facility ''TANDY'' of ETH Zurich. In 2013 and 2015 vegetation, litter and soil drill core samples were taken in the contaminated area in Fukushima prefecture. In 2015 samples were taken as close to the sampling locations of the 2013 campaign as possible. After isolation of plutonium and uranium by chemical extraction, separate targets were prepared for the measurement. The {sup 240}Pu/{sup 239}Pu ratios indicate global fallout as the plutonium source for most samples. The plutonium of the reactors of Fukushima Dai-ichi is located in the upper layers like in vegetation or litter. From the uranium ratios alone the reactors could not unambigously be identified as the source of {sup 236}U. However, this is plausible in the cases were reactor plutonium was detected. None of the samples contained higher plutonium activity concentrations than in the rest of Japan, caused by global fallout. This holds even for the samples where the reactors were identified as the source from the isotope ratios. This and the strong localization, even for neighboring sampling sites, indicate that the overall small quantities of plutonium were most likely released as particulate matter.

  19. Production of diesel fuels from vegetable oils by means of homogenous catalysed metathesis of methyl oleate; Gewinnung von dieselartigen Kraftstoffen aus Pflanzenoelen mittels homogen katalysierter Metathese von Methyloleat

    Energy Technology Data Exchange (ETDEWEB)

    Erben, Friedrich; Paetzold, Eckhard [Rostock Univ. (Germany). Leibniz-Institut fuer Katalyse; Schuemann, Ulrike; Wichmann, Volker; Fluegge, Evelyn; Berndt, Silvia; Harndorf, Horst [Rostock Univ. (Germany). Lehrstuhl fuer Kolbenmaschinen und Verbrennungsmotoren; Kragl, Udo [Rostock Univ. (Germany). Leibniz-Institut fuer Katalyse; Rostock Univ. (Germany). Inst. fuer Chemie

    2013-10-01

    Due to the increasing shortage of fossil combustibles renewable resources like oils and fats have great potential for the production of diesel-like fuels. A key step in adapting the properties of biogenic fuels to those from fossil sources is cracking or isomerisation of linear hydrocarbon chains. This is necessary for optimal cold flow properties and a continuously rising boiling curve. The present work describes the potential of metathesis for this purpose. By formal exchange of parts of molecules of a small number of starting materials a variety of products is formed which exhibit a fuel-like composition. Ethenolysis as well as hexenolysis is examined, whereat hexenolysis owns the greater potential for production of diesel-like fuels out of unsaturated fatty acid esters. (orig.)

  20. Analysis of novel silicon and III-V solar cells by simulation and experiment; Analyse neuartiger Silizium- und III-V-Solarzellen mittels Simulation und Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Hermle, Martin

    2008-11-27

    This work presents various simulation studies of silicon and III-V solar cells. For standard silicon solar cells, one of the critical parameters to obtain good performance, is the rear side recombination velocity. The optical and electrical differences of the different cell structures were determined. The optical differences and the effective recombination velocity Sback of the different rear side structures for 1 Ohmcm material were extracted. Beside standard silicon solar cells, back junction silicon solar cells were investigated. Especially the influence of the front surface field and the electrical shading due to the rear side, was investigated. In the last two chapters, III-V solar cells were analysed. For the simulation of III-V multi-junction solar cells, the simulation of the tunneldiode is the basic prerequisite. In this work, the numerical calibration of an GaAs tunneldiode was achieved by using an non-local tunnel model. Using this model, it was possible to successfully simulate a III-V tandem solar cell. The last chapter deals with an optimization of the III-V 3-junction cell for space applications. Especially the influence of the GaAs middle cell was investigated. Due to structural changes, the end-of-life efficiency was drastically increased.

  1. Utilization of surface-near geothermal energy by means of energy piles and geothermal probes; Nutzung der oberflaechennahen Geothermie mittels Energiepfaehlen und Erdwaermesonden

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Xiaolong

    2013-05-01

    In collaboration with the Institute of Thermo-Fluid Dynamics (Hamburg, Federal Republic of Germany), a pilot plant for geothermal and sorption supported air-conditioning was built in the dockside area of Hamburg. The author of the book under consideration investigates a geothermal power plant with five energy poles and three boreholes. The economic and environmental benefits of this pilot plant were detected. The thermodynamic behavior of these energy piles was numerically simulated very well. The complex processes in the energy pile and in the soil could be mapped By means of a thermal-hydraulic-mechanical coupled simulation. The extraction capacity of a geothermal probe could be significantly increased by means of a combination of a groundwater circulation method with borehole heat exchangers.

  2. Design of modern vehicle electrical systems based on co-simulation and a model library; Entwurf moderner Bordnetze mittels Co-Simulation und Modellbibliothek

    Energy Technology Data Exchange (ETDEWEB)

    Zehetner, Josef; Lu, Di Wenpu; Watzenig, Daniel [Virtual Vehicle Research Center, Graz (Austria)

    2013-08-15

    The complexity of vehicle electrical and electronic systems, components, and functions is growing as they become increasingly networked with each other and with the internet. Vehicle electrical systems developers can manage this complexity now and in the future by employing simulation as a central tool in designing powerful and reliable vehicle electrical systems. Bosch Engineering offers a powerful simulation tool to support the design of vehicle power nets from initial requirements to final series approval, now being used also for hybrid and electric drive train development. (orig.)

  3. Innovative technologies for emitter formation of crystalline silicon solar cells using in-line diffusion; Innovative Technologien zur Emittererzeugung fuer kristalline Silizium-Solarzellen mittels Durchlaufdiffusion

    Energy Technology Data Exchange (ETDEWEB)

    Voyer, Catherine

    2009-04-20

    An in-line emitter formation process for crystalline silicon solar cells was developed. The wafers were coated at room temperature with dilute phosphoric acid (2.5 w/w% in water) using ultrasonic spraying and then heated up to temperatures around 900 C in a metal-contamination-free in-line furnace. In the first zones of the furnace, a phosphosilicate glass (PSG) is formed on the silicon surface and serves as the doping source. The PSG thickness was adjusted by varying the flow rate of dilute phosphoric acid to the spray nozzle and took on values appropriate for emitter formation, in the range of {proportional_to}40-120 nm. A surfactant mixture was added to the dilute phosphoric acid in order to obtain complete wetting of the silicon surface. The mixture, which was composed of a hydrocarbon surfactant and of a fluorosurfactant, achieved better wetting properties than would be possible when using only one of the two surfactants. The spray solution containing only the hydrocarbon surfactant achieved a faster drop flattening, while the spray solution containing only the fluorosurfactant achieved a lower static surface tension. The mixture allowed for a combination of these desired properties: The drops coalesced together sufficiently rapidly (before drying) on the silicon surface to form a complete dopant source liquid layer and this layer remains sufficiently homogeneous during the layer drying. The sprayed-on layer is thicker ({proportional_to}15 microns) than the height of the surface texture ({proportional_to}5-10 microns). The liquid strives for a state of equilibrium, a convex meniscus. The topography of the liquid surface at the time at which the increase in viscosity puts an end to the liquid flow is reflected in the topography of the PSG thickness. The corresponding variations in sheet resistance across a wafer are sufficiently small for solar cells. Furthermore, the liquid layer conforms itself, during the drying, to the surface texture on a microscopic scale, and thus the PSG thickness and the emitter essentially follow the surface texture, as seen on SEM pictures. Through dehydration of the phosphorus molecules and reaction with silicon, the layer turns into a PSG. This process produces a vapour which contains water and phosphorus compounds. A steeper heat-up curve or a higher vapour pressure leads to a thicker PSG. In this work, a high PSG thickness homogeneity was obtained through adjustment of the air supply in the furnace entrance area. It was furthermore shown that under the condition of a steep heat-up curve, the PSG formation is only completed at temperatures above 700 C. The influence of the furnace transport speed and plateau temperature and of the spray nozzle flow rate on the emitter doping profile was examined. A lower speed or a higher temperature resulted in a lower sheet resistance. Moreover, the emitter phosphorus surface concentration was increased or reduced through, respectively, an increase or a reduction of the spray nozzle flow rate. The dependence of sheet resistance on PSG thickness was found to show a non-monotonous behaviour: Sheet resistance first decreased with increasing PSG thickness, reached a minimum and then increased. The reduction is explained by the increasing amount of phosphorus available for diffusion into silicon. The increase is assumed to be due to the longer time and greater energy requirement for PSG formation from a thicker dopant source layer, which leads to a weaker phosphorus diffusion into silicon in the first zones of the furnace. A high homogeneity of sheet resistance was obtained, for example a relative standard deviation of 2.5% on a textured surface. Standard screen-printed Cz-Si solar cells were made which had high values of open-circuit voltage of up to 626 mV, of short-circuit current of up to 36 mA/cm{sup 2} and of efficiency of up to 17.5%. In addition, the doping profile was varied. Textured solar cells with in-line diffusion achieved an efficiency of up to 16.8% compared to 16.5% for the reference solar cells with tube furnace diffusion. High fill factors of up to 79.9% showed the high homogeneity of the emitters formed using in-line diffusion. Using wafers from five heights of a mc-Si column, minority carrier lifetimes were measured and solar cells were fabricated. A longer or double-sided in-line diffusion led on average to higher lifetimes than a shorter or single-sided one respectively, and a tube furnace diffusion led on average to higher lifetimes than an in-line diffusion, but these differences were small and ambiguous. A clear influence of the doping profile was however observed: The longer in-line diffusion led to the highest efficiencies of up to 15.2% on non-textured silicon.

  4. Characterization of plasma-functionalized surfaces by means of Tof-SIMS and multivariate analysis methods; Charakterisierung von plasmafunktionalisierten Oberflaechen mittels ToF-SIMS und multivariaten Analysemethoden

    Energy Technology Data Exchange (ETDEWEB)

    Gradowski, M. von

    2006-11-13

    The basic principles and opportunities of surface characterisation of selected functionalised samples via ToF-SIMS (time-of-flight secondary ion mass spectrometry) are presented. One major focus of the project was the investigation of non-cohesive surface layers which could exhibit either domain like structure or well defined single functionalised surfaces. By means of ToF-SIMS with the ability of displaying the lateral distribution of surface fragments information on the structure and surface density of specific fragments on the investigated film can be obtained. The combination of the ToF-SIMS experiment with a multivariate algorithm (partial least squares, PLS) provides an interesting opportunity to quantitatively determine surface properties such as elemental and molecular concentrations. Due to the fact that the ToF-SIMS spectrum consist of a huge amount of intensities, a single one-dimensional correlation (e.g. CF{sub 3} fragment intensity <-{yields} CF{sub 3} concentration) would disregard the rest of the spectral information. The large number of fragment intensities in the spectrum is representative for the chemical structure of the analysed surface. Therefore, it is crucial to consider this total information for the quantification of surface properties (element concentration, water contact angle etc.). Furthermore, this method allows the determination of surface properties with a lateral resolution of a few microns only. This can be used for chemically structured surfaces which for many applications show micrometer sized surface structures. Finally, a successful application of the multivariate models is presented for samples from the biological and medical area. Human fibroblasts and pancreas cells have been cultivated on plasma functionalised surfaces in order to study the influence of the functionalisation on the cell growth. The samples have been covered by TEM grids with meshes in the {mu}m range before the plasma treatment to generate structured surfaces. By applying the multivariate models onto the ToF-SIMS spectra quantitative surface properties could then be assigned to each {mu}m-sized surface area which are crucial in interpreting the cell growth on the surface. (orig.)

  5. Measurement of transvers spin effects by means of two-hadron correlations in the COMPASS experiment; Messung transversaler Spineffekte mittels zwei Hadronen Korrelation am COMPASS-Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Massmann, Frank Michael

    2008-06-23

    The quark structure of the nucleon can at neglection of intrinsic quark transverse momenta be completely described by two quark distribution functions. These are the unpolarized quark distribution function q(x), the helicity distribution function {delta}q(x), and the transvers quark-spin distribution function {delta}{sub T}q(x). This lastly mentioned function called transversity function, is chirallyn odd an can therefore only be measured in a combination with another chirally odd function. An access possibility to the transversity function {delta}{sub T}q(x) is the semi-inclusive two-hadron production in deep inelastic scattering on a transversely polarized target. Thereby the folding of the chirally odd two-hadron interference fragmentation function (IFF) H{sub 1} {sup angle} (z,M{sub h}{sup 2}) and the chirally odd transversity function. The IFF H{sub 1} {sup angle} (z,M{sub h}{sup 2}) is the spin-dependent part of a fragmentation function, which describes the fragmentation of a transversely polarized quark in two unpolarized hadrons. The production of the two hadrons pursues in an interference between different wave-state of the hadron pairs. Azimuthal asymmetries in the produced hadron pairs are measured. The measurements, which are described in this thesis, were performed in the COMPASS experiment at CERN in the years 2002-2004, which is a solid-state-target experiment at the SPS accelerator. After an introduction in chapter 2 the basing theoretical concepts for the measurement of the transversity function are presented. In chapter 3 the COMPASS experiment is described. Finally in chapter 4 the evaluation methods are discussed, the results of the azimuthal asymmetries shown and compared with theoretical predictions. [German] Die Quark-Struktur des Nukleons laesst sich bei Vernachlaessigung intrinsischer Quarktransversalimpulse vollstaendig durch drei Quark Verteilungsfunktionen beschreiben. Diese sind die unpolarisierte Quark Verteilungsfunktion q(x), die Helizitaets- Verteilungsfunktion {delta}q(x) und die transversale Quarkspin Verteilungsfunktion {delta}{sub T}q(x). Diese letztgenannte Funktion, genannt ''Transversity'' Funktion, ist chiral ungerade und kann deshalb nur in Kombination mit einer anderen chiral ungeraden Funktion gemessen werden. Eine Zugangsmoeglichkeit zur ''Transversity'' Funktion {delta}{sub T}q(x) ist die semi-inklusive zwei Hadronenproduktion in tief inelastischer Streuung an einem transversal polarisierten Target. Dabei misst man die Faltung der chiral ungeraden zwei Hadronen Interferenz Fragmentationsfunktion (IFF) H{sub 1} {sup angle} (z,M{sub h}{sup 2}) und der chiral ungeraden ''Transversity'' Funktion. Die IFF H{sub 1} {sup angle} (z,M{sub h}{sup 2}) ist der spinabhaengige Teil einer Fragmentationsfunktion, die die Fragmentation eines transversal polarisierten Quarks in zwei unpolarisierte Hadronen beschreibt. Die Produktion der zwei Hadronen erfolgt in einer Interferenz zwischen verschiedenen Wellenzustaenden der Hadronenpaare. Man misst azimuthale Asymmetrien in den erzeugten Hadronenpaaren. Die Messungen, die in dieser Arbeit beschrieben werden, wurden am COMPASS Experiment am CERN in den Jahren 2002-2004 durchgefuehrt, welches ein Feststoff Target Experiment am SPS Beschleuniger ist. Nach einer Einfuehrung werden in Kapitel 2 die zugrundeliegenden theoretischen Konzepte zur Messung der ''Transversity'' Funktion vorgestellt. In Kapitel 3 wird das COMPASS Experiment beschrieben. Schliesslich werden in Kapitel 4 die Auswertemethoden besprochen, die Ergebnisse der azimuthalen Asymmetrien gezeigt und mit theoretischen Vorhersagen verglichen. (orig.)

  6. Structural analysis of a flexure tilt table by using finite element method; Strukturanalyse eines Biege-Kipp-Tisches mittels Finite-Elemente-Methode

    Energy Technology Data Exchange (ETDEWEB)

    Schust, Matthias

    2012-08-15

    At the research institute DESY the synchrotron radiation source PETRA III is operated at Hamburg site. The facility is the most powerful lightsource of its kind and enables scientists to use X-ray beams with hitherto unattained brilliance. In a so-called double-crystal monochromator certain wavelengths can be selected from the light. In these systems tilt tables with flexure hinges are used. So far, a certain susceptibility of the assembly to vibration can be seen, which decreases the beam quality. The goal of this thesis is to determine the causes of the problem and to discuss the findings concerning the known behavior. First of all the functioning of the tilt table will be explained. Afterwards the theory of flexure hinges and the boundary conditions of a finite element analysis will be treated. Using a simulation program, several assembly models will be investigated and parameter studies are carried out. Beginning with the base object of investigation - the tilt table - the model of the whole assembly is systematically developed. Natural frequencies, the stress at the spring hinges and the displacement of the crystal surface can be determined. The results of the research show that the vibration behavior of the assembly is very complex and cannot be comprehensively described within the analyses carried out. The cause of the problems has not been identified yet and therefore further studies would be necessary. (orig.)

  7. Validierung der Wirksamkeitsprüfung für Clostridium tetani Impfstoffe ad usum veterinarium durch den direkten Nachweis von Tetanus-Antitoxin im Zieltier mittels ELISA

    OpenAIRE

    Roßkopf, Ute

    2007-01-01

    Die dargelegten Ergebnisse zur Validierung einer neuen Wirksamkeitsprüfung von Tetanus-Impfstoffen resultieren aus umfangreichen Feldstudien, durchgeführt mit neun unterschiedlichen Impfstoffen für das Pferd sowie acht Impfstoffen für das Schaf. Insgesamt wurden 102 Pferde und 82 Schafe entsprechend den Angaben in der Gebrauchsinformation immunisiert. Blutentnahmen fanden nach einem vorgegebenen Schema von bis zu zwei Jahren nach der ersten Impfung statt. Die Impfstoffe waren entweder monoval...

  8. Fabrication of uranium-based ceramics using internal gelation for the conversion of trivalent actinides; Herstellung uranbasierter Keramiken mittel interner Gelierung zur Konversion trivalenter Actinoiden

    Energy Technology Data Exchange (ETDEWEB)

    Daniels, Henrik

    2012-07-01

    Alternative to today's direct final waste disposal strategy of long-lived radionuclides, for example the minor actinides neptunium, americium, curium and californium, is their selective separation from the radioactive wastestream with subsequent transmutation by neutron irradiation. Hereby it is possible to obtain nuclides with a lower risk-potential concerning their radiotoxicity. 1 neutron irradiation can be carried out either with neutron sources or in the next generation of nuclear reactors. Before the treatment, the minor actinides need to be converted in a suitable chemical and physical form. Internal gelation offers a route through which amorphous gel-spheres can be obtained directly from a metal-salt solution. Due to the presence of different types of metal ions as well as changing pH-values in a stock solution, a complex hydrolysis behaviour of these elements before and during gelation occurs. Therefore, investigations with uranium and neodymium as a minor actinide surrogate were carried out. As a result of suitable gelation-parameters, uraniumneodymium gel-spheres were successfully synthesised. The spheres also stayed intact during the subsequent thermal treatment. Based upon these findings, uranium-plutonium and uranium-americium gels were successfully created. For theses systems, the determined parameters for the uraniumneodymium gelation could also be applied. Additionally, investigations to reduce the acidity of uranium-based stock solutions for internal gelation were carried out. The necessary amount of urea and hexamethylenetetramine to induce gelation could hereby be decreased. This lead to a general increase of the gel quality and made it possible to carry out uranium-americium gelation in the first place. To investigate the stability of urea and hexamethylenetetramine, solutions of these chemicals were irradiated with different radiation doses. These chemicals showed a high stability against radiolysis in aqueous solutions.

  9. Fast determination of strontium-89 and strontium-90 by simultaneous Cerencov- and Proportional-Counting; Schnelle Bestimmung von Strontium-89 und Strontium-90 mittels simultaner Cerenkov- und Proportionalzaehlrohrmessung

    Energy Technology Data Exchange (ETDEWEB)

    Laerbusch, Karin; Wiezorek, Claus [Chemisches und Veterinaeruntersuchungsamt MEL, Muenster (Germany)

    2014-01-20

    The presented method for simultaneous determination of Sr 89 and Sr 90 combines the techniques of Cerencov- and Proportional-Counting. Due to the low limit of detection of the latter technique, the method is very sensitive for the total radiostrontium. The distribution among two measurement devices offers the advantage of time saving.

  10. Verification of the weak equivalence principle of supports and heavy masses using SQUIDs; Ueberpruefung des schwachen Aequivalenzprinzips von Traegern und schwerer Masse mittels Squids

    Energy Technology Data Exchange (ETDEWEB)

    Vodel, W.; Nietzsche, S.; Neubert, R. [Friedrich-Schiller-Universitaet Jena (Germany). Inst. fuer Festkoerperphysik; Dittus, H. [Univ. Bremen (Germany). Zentrum fuer angewandte Raumfahrttechnologie und Mikrogravitation

    2003-07-01

    The weak equivalence principle is one of the fundamental hypotheses of general relativity and one of the key elements of our physical picture of the world, but since Galileo there has been no satisfactory way of verifying it. The new SQUID technology may offer a solution. The contribution presents the experiments of Jena University. Applications are envisaged, e.g., in the STEP space mission of the NASA/ESA. [German] Das Schwache Aequivalenzprinzip ist eine der grundlegenden Hypothesen der Allgemeinen Relativitaetstheorie und damit einer der Grundpfeiler unseres physikalischen Weltbildes. Obwohl es seit den ersten Experimenten von Galileo Galilei am Schiefen Turm zu Pisa im Jahre 1638 bis heute schon zahlreiche und immer praeziser werdende Messungen zur Ueberpruefung der Aequivalenz von schwerer und traeger Masse gegeben hat, ist die strenge Gueltigkeit dieses fundamentalen Prinzips experimentell vergleichsweise unzureichend bestimmt. Neuere Methoden, wie der Einsatz SQUID-basierter Messtechnik und die Durchfuehrung von Experimenten auf Satelliten, lassen Verbesserungen schon in naher Zukunft erwarten, so dass theoretische Ueberlegungen zur Vereinigung aller uns bekannten physikalischen Wechselwirkungen, die eine Verletzung des Schwachen Aequivalenzprinzips voraussagen, experimentell eingegrenzt werden koennten. Der Beitrag gibt einen Ueberblick ueber die an der Universitaet Jena entwickelte SQUID-basierte Messtechnik zum Test des Aequivalenzprinzips und fasst die bisher bei Freifallversuchen am Fallturm Bremen erzielten experimentellen Ergebnisse zusammen. Ein Ausblick auf die geplante Raumfahrtmission STEP der NASA/ESA zum Praezisionstest des Schwachen Aequivalenzprinzips schliesst den Beitrag ab. (orig.)

  11. Methodological study of aging effects on fuel cells using X-ray synchrotron radiography and tomography; Methodische Untersuchung von Alterungseffekten an Brennstoffzellen mittels Synchrotronradiografie und -tomografie

    Energy Technology Data Exchange (ETDEWEB)

    Arlt, Tobias

    2012-04-05

    In the present work, new and advanced methods for the investigation of methanol and hydrogen powered fuel cells were analyzed. Synchrotron radiography and tomography were applied to investigate materials and transport processes in operating fuel cells ''in-situ'' and non-destructively. The corrosion of ruthenium is a key issue during aging of direct methanol fuel cells (DMFC). Therefore the influence of different aging processes on the distribution of ruthenium is of great interesting. An imaging method based on X-ray absorption spectroscopy (XAS) was applied to investigate the changes in the distribution of fuel cell catalysts three-dimensionally. Using monoenergetic synchrotron radiation it was shown that the distribution of ruthenium (Ru) in the anode catalyst changes after application of an accelerated aging procedure. A strong influence on the flowfield and the gas diffusion layer structures on the Ru distribution were found in the gas diffusion electrode at the anode side. Additionally some ruthenium moves through the membrane from the anode to the cathode. The redistribution caused by the accelerated aging procedure strongly differs from that obtained after aging under realistic stack operation (here over 1700 h) of a fuel cell in a pallet transporter. For the tomographic investigations samples were taken out from a stack operation in aged membrane electrode assembly (MEA) and were analyzed ex-situ. It was shown that the Ru redistribution can be attributed to mass transport processes (CO{sub 2} and H{sub 2}O) in the gas diffusion layer (GDL). Other high energy resolved measurements showed that the strength of the oxidation of ruthenium and platinum depends on the spatial distribution of the ruthenium. Last mentioned - also for the platinum catalyst - could be given quantitatively by means of this newly developed method. In the second part of this work high temperature polymer electrolyte fuel cells (HT-PEFC) were investigated. No liquid water can be found due to the high operation temperature of 160-200 C in this cell type. Hence conventional analysis methods are not applicable here. In especial the product water is very important for the electrical conductivity of the membrane and changes the state of the phosphoric acid inside the membrane and the electrodes. For the first time, the water balance in a HT-PEFC at different operating conditions was characterized in-situ during cell operation. The characterization was based on measured changes in the membrane transmittance and its thickness. Suitable models allowed calculating the water balance of the membrane. The influence of different operating conditions on the redistribution of the phosphoric acid between the electrodes and in the membrane was analyzed. The analysis is complemented with investigations of polarization curve recording and electrochemical impedance spectroscopy.

  12. Determination of the electromagnetic dipole strength distribution in medium-heavy atomic nuclei by means of nuclear resonance fluorescence; Bestimmung der elektromagnetischen Dipolstaerkeverteilung in mittelschweren Atomkernen mittels Kernresonanzfluoreszenz

    Energy Technology Data Exchange (ETDEWEB)

    Massarczyk, Ralph Jens

    2011-01-17

    During the last hundred years several models were developed to describe the configuration of nuclei. These models have to make predictions, which should be comparable with experiments. As a standard type of experiment the nuclear resonance fluorescence was established. A nucleus is excited by irradiation with photons. By emitting one or more photons the nucleus decays back to the ground state. With this method it is possible to measure energy levels and to determine the strength of their excitation. A continuum of unresolved peaks gives additional strength. The existing setup at the linear electron accelerator ELBE of the Forschungszentrum Dresden-Rossendorf uses bremsstrahlung, produced as a secondary beam in a thin Niobium foil. During the years 2008/09 experiments on the nuclei of {sup 86}Kr and {sup 136}Ba took place there. In this work they will be analyzed. Photon flux and efficiency determination have been done as well as simulations on detector response and non-nuclear scattered background events. For this purpose the GEANT4 package was used. Finally the resulting cross sections were corrected for branching and feeding.

  13. Reliabilitätskriterien für die Messung der Lebersteifigkeit mittels Echtzeit-2D-Shearwave-Elastografie bei verschiedenen klinischen Szenarien der chronischen Lebererkrankung

    DEFF Research Database (Denmark)

    Thiele, M; Stæhr Madsen, Bjørn; Procopet, B

    2017-01-01

    Purpose: Liver stiffness measurement by real-time 2-dimensional shear wave elastography (2D-SWE) lacks universal reliability criteria. We sought to assess whether previously published 2D-SWE reliability criteria for portal hypertension were applicable for the evaluation of liver fibrosis......-SWE measurements from 142 patients. Overall, the variability in liver stiffness within single 2D-SWE measurements was low (SD = 1.1 ± 1.5kPa; SD/mean = 12 ± 9 %). Intra-observer analysis showed almost perfect concordance (intraclass correlation coefficient = 0.95; 95 % CI 0.94 - 0.96; average difference from...

  14. Determination of W-erosion through optical spectroscopy under ITER-relevant plasma conditions; Bestimmung der Wolframerosion mittels optischer Spektroskopie unter ITER-relevanten Plasmabedingungen

    Energy Technology Data Exchange (ETDEWEB)

    Laengner, Marko

    2016-11-21

    Tungsten (W) is used in present fusion experiments and is as well a material choice for future reactors like ITER and DEMO. However, tungsten eroded from the wall leads to high radiation losses in the plasma and the transport to the plasma center to critical plasma cooling. Therefore a detailed investigation of the interaction between eroded tungsten and the plasma is necessary. The emission of tungsten line radiation in the plasma and thus the shape of the emission profiles is characterized by excitation and ionisation. Quantitatively the ionisation can be described in terms of the ionisation rate coefficients. This knowledge is necessary for the interpretation of spectroscopic data and especially to determine tungsten fluxes into the plasma that are caused by tungsten erosion. Up to now, ionisation rate coefficients for neutral tungsten were not determined except for the plasma temperature range below 20 eV. For higher temperatures only uncertain calculated data or semi-empirical data is available. Therefore, within this thesis for the first time ionisation and emission processes of tungsten originating from tungsten erosion were investigated in the temperature range between (41±8) eV and (81±8) eV at the tokamak TEXTOR and ionisation rate coefficients were determined experimentally. Measured emission profiles of the W I(400.88 nm)-line show a typical exponential decrease that is caused by the ionisation of the neutral tungsten atoms. But moreover, at a distance of 1 to 2 mm away from the sputtered surface the emission initially increases to a maximum. By introducing a relaxation time between 0.5 and 1 μs before reaching the equilibrium of the population of the emitting energy level of this line the increase of the emission profiles can be reproduced. Simulating the emissions profiles through a Monte-Carlo-simulation that was developed in the scope of this thesis results in ionisation rate coefficients that are identical with values calculated through using the semi-empirical Lotz-formula. The necessary extension of the atomic data base regarding neutral tungsten leads to the interest in a tungsten source that can easily be used for calibration purposes. This was realised at TEXTOR through the injection of WF{sub 6}. The tungsten that was brought into the plasma via WF{sub 6}-injection was investigated regarding the comparability to tungsten originating from a sputtering process. Moreover was WF{sub 6} used for the first time to determine conversion factors - the so-called photon efficiencies - to calculate tungsten fluxes from spectroscopically measured photon fluxes. For the given combinations of temperature and density from (20±5) eV to (82±5) eV and from (2.2±1) x 10{sup 12} cm{sup -3} to (6.8±1) x 10{sup 12} cm{sup -3}, respectively, for the W I(400.88 nm)-line a constant average value of left angle E{sup WI(400.88} {sup nm)}{sub Ph} right angle =94±16 is found. To test these values sputtering yields were determined from the amount of eroded tungsten atoms. These sputtering yields are in line with experimental reference values and calculations. The prevailing investigated plasma conditions are in the range of what can be expected considering the ITER divertor during ELMs. The found experimental results are consistent and confirm the match between WF{sub 6} photon efficiencies and photon efficiencies of sputtered tungsten.

  15. Energy conservation potentials in the countries of Central and Eastern Europe - an expose of theses; Die Energiespeicherpotentiale in den Laendern Mittel- und Osteuropas - eine Darstellung der Thesen

    Energy Technology Data Exchange (ETDEWEB)

    Riesner, W. [Hochschule fuer Technik, Wirtschaft und Sozialwesen Zittau/Goerlitz FH, Zittau (Germany)

    1996-07-01

    The report compares western and eastern Europe in terms of their supply with fossil energy, the development of their primary and end-use energy consumption, and the development of their gross power generation. The technical state of energy conversion plants and electrothermal power plants, Russia`s energy conservation potential, and the efficacy of measures for enhancing electric energy efficiency in the Ukraine are described. Finally, a comparison of energy input coefficients and energy costs between the old and new federal states of Germany is made. (DG) [Deutsch] Bezueglich der Versorgung mit fossiler Energie, der Entwicklung des Primaer- und Endenergieverbrauchs und der Entwicklung der Brutto-Stromerzeugung werden West- und Osteuropa miteinander verglichen. Der technische Stand der Energieumwandlungsanlagen und der Elektrowaermeanlagen sowie das Energieeinsparungspotential in Russland und die Effektivitaet von Massnahmen zur Elektroenergieeffizienzsteigerung in der Ukraine werden dargestellt. Schliesslich erfolgt ein Vergleich der Energieintensitaets- und Energiekosten zwischen den alten und neuen Bundeslaendern der BRD. (DG)

  16. Measurement of hydrogen distributions in iron and steel by means of neutron radiography and tomography; Messung von Wasserstoffverteilungen in Eisen und Stahl mittels Neutronenradiographie und -tomographie

    Energy Technology Data Exchange (ETDEWEB)

    Griesche, Axel; Kannengiesser, Thomas [BAM Bundesanstalt fuer Materialforschung und -pruefung, Berlin (Germany); Kardjilov, Nikolay; Manke, Ingo [Helmholtz-Zentrum Berlin (HZB), Berlin (Germany); Schillinger, Burkhard [Technische Univ. Muenchen, Garching (Germany)

    2015-07-01

    In recent years, the optimization of the radiography measuring stations at research reactors and in particular the development of the neutron detectors has enabled the measurement of hydrogen distributions with ever higher spatial resolution at the same time more sensitive detection limit. Compared to iron, hydrogen has a high interaction cross-section for neutrons, and thus allows simple radiographic methods of the two and three dimensional visualization of hydrogen distribution in the structure. This allowed us for the first time the measurement of hydrogen diffusion flows in centimeter-thick steel samples with a temporal resolution of 20 s and the quantitative measurement of hydrogen accumulation of crack edges in hydrogen embrittled iron samples. It was also the first gaseous hydrogen detected in the cavities of the cracks and the pressure can be determined. This new quality of information on the microstructure scale granted unprecedented insights for the investigation of damage mechanisms e.g. in the hydrogen embrittlement. By providing local in-situ information that is not accessible by conventional methods such as carrier gas hot extraction, as well as analyzes can be performed in three dimensions with a spatial resolution of 20-30 μm. This article provides examples that use the spatial and temporal resolution of the neutron radiography and tomography to visualize hydrogen distributions in and around cracks and to quantify. The measurements were conducted at the research reactors BER II of HZB in Berlin and FRM II of teh neutron source Heinz Maier-Leibnitz in Garching. (This article contains PowerPoint slides). [German] In den letzten Jahren hat die Optimierung der Radiographie-Messplaetze an Forschungsreaktoren und hier insbesondere die Weiterentwicklung der Neutronendetektoren die Messung von Wasserstoffverteilungen mit immer hoeherer Ortsaufloesung bei gleichzeitig empfindlicherer Nachweisgrenze ermoeglicht. Wasserstoff besitzt im Vergleich zu Eisen einen hohen Wechselwirkungsquerschnitt fuer Neutronen und erlaubt somit mit einfachen radiographischen Methoden die zwei- und dreidimensionale Visualisierung von Wasserstoffverteilungen im Gefuege. Dies ermoeglichte uns erstmals die Messung von Wasserstoffdiffusionsstroemen in zentimeterdicken Stahlproben mit einer zeitlichen Aufloesung von 20 s sowie die quantitative Messung von Wasserstoffansammlungen an Rissflanken in wasserstoffversproedeten Eisenproben. Dabei konnte auch erstmals gasfoermiger Wasserstoff in den Hohlraeumen der Risse nachgewiesen werden und dessen Druck bestimmt werden. Diese neue Qualitaet der Information auf der Mikrostrukturskala gewaehrt noch nie dagewesene Einblicke fuer die Aufklaerung von Schaedigungsmechanismen z. B. bei der Wasserstoffversproedung. Durch die Bereitstellung von lokalen in situ Informationen, die mit herkoemmlichen Methoden wie der Traegergas-Heissextraktion nicht zugaenglich sind, koennen so auch Analysen in drei Dimensionen mit einer Ortsaufloesung von 20-30 μm durchgefuehrt werden. In diesem Beitrag werden Beispiele gezeigt, die die Orts- und Zeitaufloesung der Neutronenradiographie und -tomographie nutzen, um Wasserstoffverteilungen in und an Rissen zu visualisieren und zu quantifizieren. Die Messungen wurden an den Forschungsreaktoren BER II des HZB in Berlin und FRM II der Neutronenquelle Heinz Maier-Leibnitz in Garching durchgefuehrt.

  17. Biogas desulfurization with a new developed doped activated carbon. 20 month pilot test; Biogasfeinentschwefelung mittels neu entwickelter dotierter Aktivkohle. 20-monatiger Praxistest

    Energy Technology Data Exchange (ETDEWEB)

    Rossow, Silvana; Deerberg, Goerge; Goetze, Toralf; Kanswohl, Norbert; Nelles, Michael [Univ. Rostock (Germany). Lehrstuhl fuer Abfall- und Stoffstromwirtschaft

    2009-05-15

    Doped activated carbon is a special developed activated carbon for the desulfurization of technical gases. Based on its special adsorption properties, it is able to bond a large amount of hydrogen sulfide. By the special manufacturing method it was possible to optimize further the performance for the desulfurization of gases. In a biogas plant with an installed electric capacity of 2 MW the functionality of the doped activated carbon was proofed in a real biogas stream in a 20 month pilot test. The activated carbon was used in a special adsorption system that was tunes on the requirement of the activated carbon and on the site of installation. Because the biogas plant was in the starting period, all the time there were variable operation conditions. In spite of the variable conditions the doped activated carbon shows a permanent complete desulfurization, as in the executed laboratory experiments. By the use of the desulfurization system the concentration of hydrogen sulfide is decreased less than 1 ppm. The prejudices with are often caused by hydrogen sulphide could not identify until now. A positive evidence of the excellent desulfurization is the doubling of the oil lifetime of the block heating station. (orig.)

  18. Maintenance planning for transmission routes with medium voltage overlines - experience within the framework of two pilot projects; Trassenpflegeplanung fuer Mittel- und Hochspannungsfreileitungen - Erfahrungen von zwei Pilotprojekten

    Energy Technology Data Exchange (ETDEWEB)

    Geiges, H. [Ingenieurbuero Geiges, Freiraum- und Landschaftsplanung, Laumersheim (Germany)

    1997-11-03

    On the basis of the `VDEW Orientation Aid for Maintenance Measures in Transmission Routes` two pilot projects were selected in a 110 kV and a 20 kV overhead transmission route. (orig.) [Deutsch] Auf der Grundlage der `VDEW-Orientierungshilfe zu Pflegemassnahmen in Leitungstrassen` wurden Pilotprojekte in einer 110-kV- und in einer 20-kV-Freileitungstrasse im suedlichen Pfaelzerwald ausgewaehlt. (orig.)

  19. Lambda quantification by laser optical measuring methods on a supercharged Otto engine with Benz indirect injection; Lambdaquantifizierung mittels laseroptischer Messmethoden am aufgeladenen Ottomotor mit Benzindirekteinspritzung

    Energy Technology Data Exchange (ETDEWEB)

    Rogler, Philipp

    2010-07-01

    For the optimization of upcoming SI engine generations it is indispensable to understand the mixture formation process in detail because it is the basis requirement for reducing emissions and fuel consumption. On this account, fuel sprays used for gasoline direct injection are investigated with advanced laser optical measurement techniques. The spatial fuel distribution of both vapor and liquid phase is measured with a new technology approach, in which the 3D-tomography is combined with the laser induced exciplex fluorescence to create a new technology. With this laser-induced exciplex fluorescence tomography (TLIEF) the vapor and liquid phase fuel distribution of annular orifice and multi hole injectors are investigated under stationary boundary conditions in an optically accessible spray vessel. The particle density inside the spray chamber is kept constant and set to resemble that of a typical stratified engine operation point during the injection phase. Pressure and temperature are varied for parameter studies. The 3D spray visualizations show a significant dependency of the spray propagation on the ambient temperature. The vaporized fuel generated by multihole injectors with nearby oriented spray plumes is elongated differently under high ambient temperatures (500 K) compared to room temperature. PIV flow field measurements revealed that the reason for this temperature dependent behavior is the spray induced air flow. The vapor phase, which is with increasing temperatures in greater distance from the injector predominantly present, with its, compared to fuel droplets, lower moment of inertia is stronger elongated by the spray induced air flow. For a more detailed understanding of the mixture formation processes, the air-fuel-ratio {lambda} is computed from the quantified TLIEF signals. Therefore the total fluorescence intensity within the spray volume at a time where the vaporization process has been completed is equalized to the known total injected mass. Thus the spatial {lambda}-distribution of gasoline direct injection sprays is known for all observation times and can be further evaluated quantitatively. For data evaluation new methods are developed, which allow quantitative statements with regard to spray homogeneity and inflammability. Thereby it is shown within the current work, that spray geometries which generate large eddies outside and small eddies within the spray homogenize fast and possess a better spray homogeneity. Mixture formation is furthermore studied on a transparent engine with a central mounting position of the injector. Investigated were two engine operation modes: spray guided stratified engine operation mode and supercharged homogeneous engine operation mode, both with adequate annular orifice and multi hole injectors. For quantitative data, the linear vibrational Raman spectroscopy is used as a 1D-measurement technology. Compared to solutions known from the literature, the laser optical setup is improved in such a way that measurements even during and shortly after the injection phase are feasible. In parallel of the 1D measurements, the fuel distribution is visualized with planar laser induced fluorescence (PLIF). For mixture formation analysis, many injection and engine parameters are varied. The results from transparent engine and spray vessel are associated with each other and correlated to known emission measurements of a metal engine with the same combustion chamber geometry. In order to assure a reliable inflammation and receive a combustion with low raw emissions in stratified engine operation mode, all injection and engine parameters have to be adjusted individually for each spray geometry. The optima differ depending on the combustion chamber geometry and the spray shape. In supercharged homogeneous engine operation mode it is shown that from a mixture formation point of view there is a conflict of interests between a homogeneous mixture and wall wetting for driven cycles' relevant engine operation points. The results of this work show that an injection spread over the complete intake phase results in a homogeneous mixture with minimum wall and piston wetting. This optimum in mixture formation can only be realized for all operation conditions of a given engine with a reduction in spray penetration and a controllable hydraulic flow rate of the GDI injector. (orig.)

  20. Visualization of ferroelectric domain structures in lithium niobate by means of confocal nonlinear microscopy; Visualisierung ferroelektrischer Domaenenstrukturen in Lithiumniobat mittels konfokaler nichtlinearer Mikroskopie

    Energy Technology Data Exchange (ETDEWEB)

    Berth, Gerhard

    2010-07-01

    In the field of integrated optics nonlinear-optical effects play a central role. A typical example for the commercial use of such phenomena is the frequency conversion. A deciding parameter is here the phase matching, which determines the quantity of the constructive interaction range of contributing optical fields. In view of a high efficiency of such processes the dispersion of a crystal must be balanced for the contributing frequencies. In nonlinear components on the base of optical waveguides the principle of the ''quasi-phase matching'' is applied, which uses the microdomain inversion. Phase jumps occuring at the domain boundaries compensate in the mean the different phase velocities. The application range of such periodical structures depends essentially on sharpness, homogeneity, depth extent, and period of the domain structure. The nonlinear confocal laser scanning microscopy makes a mapping of this transferred ferroelectric domain structure possible. Primary aim of this thesis is the characterization and mapping of the transferred ferroelectric domain structure in lithium niobate. A modularly kept confocal microscope makes here a nonlinear analysis in reflection and transmission geometry possible. In both geometries systematic studies as function of important process parameters were performed. It was shown that because of the larger nonlinear coherence length in the transmission modus the SHG ensues above all in forward direction. By depth-resolved studies at Z-cut PPLN structured between the surface region and the volume crystal a flippling of the SHG contrast could be observed. In samples with circular pole structure additionally in the crystal a transition to a hexagonal structure took place. In the Ti:PPLN strip waveguide a strong and specific increasement of the nonlinear signal of the domain walls was discovered. Here also the usual SHG surface contrast between dhe domains and the boundaries is inverted. Also differently processed planar and ripple structures in X- and YS-cut LN with periodic microdomains were studied. Here a strong contrast in the SH signal concerning the oppositely poled domain regions resulted, which then extends over the whole depth extension. So for instance a successful poling beyond the ripple region could be detected up to a total depth of 5 {mu}m. Further studies a a cross-section analysis of the structures suggest that the cause for the increased nonlinear signal lies in a ''filamentation'' of the inverted region. Additionally the {mu}-Raman spectroscopy was applied for the examination of the domain structure in PPLN. Here it could be shown that in dependence on the chosen Raman line both the domain boundaries and the differently oriented domains themselves can be mapped.

  1. Control of nitrification and denitrification by means of oxygen measurement in activated sludge; Steuerung der Nitrifikation und Denitrifikation mittels Sauerstoffmessung im Belebungsbecken

    Energy Technology Data Exchange (ETDEWEB)

    Svardal, K; Kroiss, H

    1998-12-31

    As the simulation results show, controlling nitrification/denitrification by means of the oxygen content is a very effective method. Its big advantage is that the concentration of O{sub 2} can be very reliably measured. In comparison with online analysis units, O{sub 2} probes demand little maintenance and are inexpensive; so, each measuring point can be supplied with its own probe. O{sub 2} measurement is indispensable also with other control strategies. It would make sense, at least at larger plants, to monitor additionally the concentration of ammonium, a parameter which makes for a higher safety margin. (orig./SR) [Deutsch] Die Simulationsergebnisse zeigen, dass die Steuerung der Nitrifikation/Denitrifikation nach dem Sauerstoffgehalt sehr gute Resultate ergibt. Der grosse Vorteil dieser Art der Steuerung besteht darin, dass die O{sub 2}-Konzentration sich sehr zuverlaessig messen laesst. O{sub 2}-Sonden sind im Vergleich zu online-Analysatoren wartungsarm und preisguenstig, so dass auch eine reduntante Ausfuehrung jeder Messstelle vertretbar ist. Auf die O{sub 2}-Messung kann auch bei anderen Steuerstrategien nicht verzichtet werden. Eine sinnvolle Ergaenzung waere zumindest bei groesseren Anlagen eine Ueberwachung der Ammoniumkonzentration wobei dieser Messwert vor allen Dingen der Sicherheit dient. (orig./SR)

  2. Experiences with the determination of Sr-89 and Sr-90 using fast methods; Erfahrungen bei der Bestimmung von {sup 89}Sr und {sup 90}Sr mittels Schnellmethoden

    Energy Technology Data Exchange (ETDEWEB)

    Kowalik, C.; Fueger, J. [Thueringer Landesanstalt fuer Umwelt und Geologie, Jena (Germany). Landesmessstelle fuer Umweltradioaktivaet

    2014-01-20

    Quick methods of the measurement of {sup 89}Sr and {sup 90}Sr have a great importance in the supervision of the environmental radioactivity. It is necessary to receive in short time dependable analytical data to be able to carry out suitable assessments or to give recommendations. The aim of the investigations was to be guaranteed the demands for these methods (test preparation, measurement and evaluation). The use of the solid phase extraction by means of commercial Sr Resin trademark columns (4.4' (5')-Di-tert-butylcyclohexanol-18-kronen-6-aether) (Triskem) to the radiochemical separation of the Sr isotopes was suitable. The measurements occurred to the FHT 770 T12 - Multi Low Level Alpha/Beta Sample Counter (Thermo Scientific). The results contain the summary activities of all available Sr isotopes, as for example {sup 89}Sr and {sup 90}Sr. The calculations of the single activities occur about the mathematical algorithm of the linear development on the basis of the works of G. Kanisch. The first results show, this method is suitable for the analysis of {sup 89}Sr and {sup 90}Sr and is used therefore in future in Thuringia.

  3. Smart Grid. Implementation of households by means of cross-linking and energy community; Smart Grid. Integration von Haushalten mittels Vernetzung und Energie-Community

    Energy Technology Data Exchange (ETDEWEB)

    Trick, U.; Steinheimer, M.; Ruhrig, P.; Toenjes, R. [Fachhochschule Frankfurt am Main (Germany); Hoelker, D. [Hochschule Osnabrueck (Germany)

    2012-07-01

    The problems arising from the increasingly volatile and decentralized power generation as well as the today's ''black box'' distribution networks are solved here by the introduction of a new concept of a peer-to-peer networked energy community. Based on the experience with communication value-added services a service management framework is introduced which allows on the one side personalized services for the smart home, especially the energy management, and includes the integration of multimedia communications. On the other side the concept provides a convenient networking of households, energy suppliers, distribution network operators and others with the objectives cost savings, avoidance of network expansion, energy saving, CO{sub 2}-reduction, etc. Initial simulations confirm the effectiveness of this new and powerful approach, most notably the benefits of battery storage in homes, but also the potential contributions of demand side integration (load shift). (orig.)

  4. Decentralized load- and feed-in-management using a market based agent system; Dezentrales Last- und Einspeisemanagement mittels eines marktbasierten Agentensystems

    Energy Technology Data Exchange (ETDEWEB)

    Linnenberg, T.; Wior, I.; Schreiber, S.; Fay, A. [Helmut-Schmidt-Univ., Hamburg (Germany). Inst. fuer Automatisierungstechnik

    2012-07-01

    As a result of the increasing amount of decentralized electricity generation classical, centralized control concepts are taken to their limits. At present, two approaches are being followed to deal with these problems: the expansion of the electricity network and the extension of reserve capacities. The ''DEcentralized MArket based POwer control System'' (DEMAPOS) approach presented in this article, illustrates ways to solve these problems by means of a decentralized, market based control. With a focus on easy expandability and the possibility to cooperate with project partners a methodic and comprehensible development process was used along with open standards and free software. The Validation of the approach was carried out simulation based on real world data. (orig.)

  5. Advances in the staging of renal cell carcinoma with high-resolution imaging; Fortschritte im Staging des Nierenzellkarzinoms mittels hochaufloesender Bildgebung

    Energy Technology Data Exchange (ETDEWEB)

    Hallscheidt, P.; Noeldge, G.; Schawo, S.; Kauffmann, G.; Palmowski, M. [Abt. Radiodiagnostik, Radiologische Klinik, Univ. Heidelberg (Germany); Bartling, S. [Medizinische Physik, DKFZ Heidelberg (Germany); Pfitzenmaier, J. [Urologische Klinik, Univ. Heidelberg (Germany)

    2007-12-15

    Modern imaging modalities such as computed tomography (CT) and magnetic resonance imaging (MRI) allow high-resolution imaging of the abdomen. Modern scanners made high temporal as well as high spatial resolution available. Therapeutic approaches to the treatment of renal cell carcinoma have been improved over the recent years. Besides conventional and open laparoscopic tumor nephrectomy and nephron sparing, surgical approaches such as local tumor cryotherapy and radiofrequency ablation (RF) are ablative modalities and are used increasingly. Improved anesthesiological methods and new surgical approaches also allow curative treatment in extended tumors. Prerequisites for preoperative imaging modalities include visualization of the kidney tumor as well as its staging. Tumor-related infiltration of the renal pelvis or invasion of the perinephric fat and the renal hilus has to be excluded prior to nephron sparing surgery. In cases with extended tumors with infiltration of the inferior vena cava, it is necessary to visualize the exact extension of the tumor growth towards the right atrium in the vena cava. The radiologist should be informed about the diagnostic possibilities and limitations of the imaging modalities of CT and MRI in order to support the urologist in the planning and performance of surgical therapeutical approaches. (orig.)

  6. Assessment of cognitive functions after prophylactic and therapeutic whole brain irradiation using neuropsychological testing; Erfassung kognitiver Funktionen nach prophylaktischer und therapeutischer Ganzhirnbestrahlung mittels neuropsychologischer Testverfahren

    Energy Technology Data Exchange (ETDEWEB)

    Penitzka, S.; Wannenmacher, M. [Universitaetsklinikum Heidelberg (Germany). Abt. Klinische Radiologie; Steinvorth, S. [Universitaetsklinikum Heidelberg (Germany). Abt. Klinische Radiologie; MIT, Cambridge, MT (United States). Dept. of Brain and Cognitive Sciences; Sehlleier, S. [Universitaetsklinikum Heidelberg (Germany). Abt. Klinische Radiologie; Universitaetsklinikum Wuerzburg (Germany). Abt. Strahlentherapie; Fuss, M. [Universitaetsklinikum Heidelberg (Germany). Abt. Klinische Radiologie; Texas Univ., San Antonio, TX (United States). Health Science Center; Wenz, F. [Universitaetsklinikum Heidelberg (Germany). Abt. Klinische Radiologie; Universitaetsklinikum Mannheim (Germany). Sektion Radioonkologie

    2002-05-01

    Purpose: Aim of this study was the assessment of neuropsychological changes after whole brain irradiation. Patients and Method: 64 patients were tested before, and 29 after whole brain irradiation, including 28 patients with small cell lung cancer (SCLC) before prophylactic cranial irradiation (PCI) and 36 patients with cerebral metastases before therapeutic cranial irradiation (TCI), as well as 14 patients after PCI and 15 after TCI (Table 1). Intelligence, attention and memory were assessed applying a 90-minute test battery of standardized, neuropsychological tests (Table 3). Results: Patients with SCLC showed test results significantly below average before PCI (n=28, mean IQ=83, SD=17). Neither after PCI, nor after TCI the tested neuropsychological functions decreased significantly (Tables 4, 5). A comparison between SCLC-patients with and without cerebral metastases before whole brain irradiation showed better test-results in patients with cerebral metastases and fewer cycles of preceding chemotherapy (Table 7). Conclusion: Neuropsychological capacity in patients with SCLC was impaired even before PCI. Possible reason is the preceding chemotherapy. Whole brain irradiation did not induce a significant decline of cognitive functions in patients with PCI or TCI. A decline in a longer follow-up nevertheless seems possible. (orig.) [German] Zielsetzung: Ziel der Studie war die Erfassung moeglicher Veraenderungen der neuropsychologischen Leistungsfaehigkeit nach Ganzhirnbestrahlung. Patienten und Methode: Untersucht wurden 64 Patienten vor und 29 Patienten nach Ganzhirnbestrahlung. Es handelte sich um 28 Patienten mit kleinzelligem Bronchialkarzinom (SCLC) vor prophylaktischer Ganzhirnbestrahlung (PCI) und um 36 Patienten mit Hirnmetastasen vor therapeutischer Ganzhirnbestrahlung (TCI). Es wurden 14 Patienten nach PCI und 15 Patienten nach TCI getestet. Zur Anwendung kam eine 90-minuetige Testbatterie standardisierter, neuropsychologischer Testverfahren zur Messung von Intelligenz, Aufmerksamkeit und Gedaechtnis. Ergebnisse: In der Patientengruppe mit SCLC lagen die Testergebnisse bereits vor der PCI deutlich unter der Norm (n=28, mittlerer Intelligenzquotient=83, Standardabweichung=17). Weder nach PCI noch nach TCI zeigte sich eine signifikante Verschlechterung der kognitiven Funktionen. Der Vergleich zwischen den Patienten mit SCLC ohne Hirnmetastasen und mit Hirnmetastasen vor Bestrahlung zeigte eine bessere Leistungsfaehigkeit der Patienten mit Hirnmetastasen und weniger Zyklen vorausgegangener Chemotherapie. Schlussfolgerung: Die neuropsychologische Leistungsfaehigkeit ist bei SCLC-Patienten bereits vor PCI eingeschraenkt. Ursache koennte die vorausgegangene Chemotherapie sein. Die Ganzhirnbestrahlung fuehrt bei Patienten mit therapeutischer oder prophylaktischer Ganzhirnbestrahlung zu keiner signifikanten Verschlechterung der kognitiven Funktionen. Eine Verschlechertung im laengeren Follow-up kann jedoch nicht sicher ausgeschlossen werden. (orig.)

  7. Non-contact test of coating by means of laser-induced ultrasonic excitation and holographic sound representation. Beruehrungslose Pruefung von Beschichtungen mittels laserinduzierter Ultraschallanregung und holographischer Schallabbildung

    Energy Technology Data Exchange (ETDEWEB)

    Crostack, H A; Pohl, K Y [QZ-DO Qualitaetszentrum Dortmund GmbH und Co. KG (Germany); Radtke, U [Dortmund Univ. (Germany). Fachgebiet Qualitaetskontrolle

    1991-01-01

    In order to circumvent the problems of introducing and picking off sound, which occur in conventional ultrasonic testing, a completely non-contact test process was developed. The ultrasonic surface wave required for the test is generated without contact by absorption of laser beams. The recording of the ultrasound also occurs by a non-contact holographic interferometry technique, which permits a large scale representation of the sound. Using the example of MCrAlY and ZrO[sub 2] layers, the suitability of the process for testing thermally sprayed coatings on metal substrates is identified. The possibilities and limits of the process for the detection and description of delamination and cracks are shown. (orig.).

  8. Manipulation of incoherent and coherent spin ensembles in diluted magnetic semiconductors via ferromagnetic fringe fields; Manipulation inkohaerenter und kohaerenter Spinensembles in verduennt-magnetischen Halbleitern mittels ferromagnetischer Streufelder

    Energy Technology Data Exchange (ETDEWEB)

    Halm, Simon

    2009-05-19

    In this thesis it is demonstrated that fringe fields of nanostructured ferromagnets provide the opportunity to manipulate both incoherent and coherent spin ensembles in a dilute magnetic semiconductor (DMS). Fringe fields of Fe/Tb ferromagnets with a remanent out-of-plane magnetization induce a local magnetization in a (Zn,Cd,Mn)Se DMS. Due to the sp-d exchange interaction, optically generated electron-hole pairs align their spin along the DMS magnetization. One obtains a local, remanent spin polarization which was probed by spatially resolved, polarization sensitive photoluminescence spectroscopy. Fringe fields from in-plane magnetized Co ferromagnets allow to locally modify the precession frequency of the Manganese magnetic moments of the DMS in an external magnetic field. This was probed by time-resolved Kerr rotation technique. The inhomogeneity of the fringe field leads to a shortening of the ensemble decoherence time and to the effect of a time-dependent ensemble precession frequency. (orig.)

  9. Gas separation of landfill gas and other biogases by pressure swing adsorption. Final report. Gastrennung fuer Deponie- und Faulgase mittels Druckwechseltechnik. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Pilarczyk, E; Mellech, L

    1986-01-01

    A new PSA-process for recovery of methane with SNG-quality from biogases was developed in the laboratory and successfully tested in field trials at the German landfill Emscherbruch/Gelsenkirchen. A special carbon molecular sieve on which carbon dioxide is adsorbed much faster than methane was proved as the best suited adsorbent for biogas separation. Even part of nitrogen which is mostly contained in landfill gases from leakage air is simultaneously removed from methane together with carbon dioxide by using the carbon molecular sieve. Low quality-SNG with 88-90% by vol. methane could be processed from landfill gas containing up to 15% by vol. nitrogen at an adsorption pressure of 3-9 bar abs. The recovery of methane goes upt to 98%. High quality-SNG can be processed from N/sub 2/-free biogases like sewage gas. The capital and operational cost (not including prepurification) for recovery of low quality-SNG by PSA is estimated to about 0,12 DM/m/sup 3/ SNG. (orig.) With 13 refs., 13 tabs., 16 figs.

  10. MR thermometry for laser-induced thermotherapy at 1.5 tesla; MR-Thermometrie bei 1,5 Tesla zur thermischen Ablation mittels laserinduzierter Thermotherapie

    Energy Technology Data Exchange (ETDEWEB)

    Meister, D.; Huebner, F.; Mack, M.; Vogl, T.J. [Frankfurt Univ. (Germany). Inst. fuer Diagnostische und Interventionelle Radiologie

    2007-05-15

    Purpose: Evaluation of thermometry with fast MR sequences for laser-induced interstitial laser therapy (LITT) and verification of the thermometric results with a fiber-optic thermometer. Method and Materials: In vitro experiments were conducted using an agarose gel mixture and pig liver lobes. MR-guided LITT was performed using a laser power between 3 and 15?watts. Thermometry was performed using longitudinal relaxation time T1 and proton resonance frequency shift (PRF) methods under acquisition of amplitude and phase shift images. PRF was measured with a fast spoiled GRE sequence. Four different sequences were used for T1 thermometry: gradient echo (GE), TrueFISP (TRUFI), Saturation Recovery Turbo-FLASH (SRTF) and Inversion Recovery Turbo-FLASH (IRTF) sequences. The temperature was controlled using a fiber-optic Luxtron device and correlated with the MR temperature. The range of applied and monitored temperatures exceeded 80 degrees Celsius. Results: The temperature dependence showed a good linear relationship up to 60 degrees Celsius. Calibration experiments for the T1 method delivered coefficients of determination from 0.977 to 0.997 for agarose and from 0.958 to 0.995 for the pig liver samples. The IRTF sequence had the highest temperature sensitivity (agarose 0.99, liver 1.19). During LITT the TRUE-FISP sequence exhibited a strong nonlinear relationship. R{sup 2} of this sequence was 0.809 in the agarose experiments. The average temperature errors when heated up to 80 degrees Celsius were 3.86 - 11.38 degrees Celsius for Agarose gel and 5.7 - 12.16 degrees Celsius for the liver tissue. SRTF and IRTF sequences exhibited the most linear relationship with temperature but were more dependent on tissue differences. (orig.)

  11. Electrochemical incineration of C-14-containing liquid wastes. First results and outlook; Behandlung C-14-haltiger fluessiger Abfaelle mittels elektrochemischer Totaloxidation. Erste Ergebnisse und Ausblick

    Energy Technology Data Exchange (ETDEWEB)

    Friedrich, Hans-Juergen [Fraunhofer-Institut fuer Keramische Technologien und Systeme (IKTS), Dresden (Germany). Aussenstelle Rossendorf; Knappik, Reinhard; Zschornack, Daniel [Verein fuer Kernverfahrenstechnik und Analytik Rossendorf e.V. (VKTA), Dresden (Germany). Fachbereich Analytik und Monitoring; Mueller, Wolfgang [IUT GmbH, Berlin (Germany)

    2014-06-15

    Liquid radioactive wastes containing carbon-14 are not acceptable for radioactive waste repository. At present incineration is the only approved way of treatment in Germany. But capacities are limited and incineration by itself is known to be a technically complex and rather expansive process. Therefore within an experimental proof of concept it should be examined whether an electrochemical incineration process is also applicable for this purpose. The R and D activities mainly comprised the gathering of informations about the chemical nature and constitution of such liquid wastes from enterprises, research laboratories and a number of the state owned collecting facilities, numerous electrochemical examinations with typical organic substances and finally electrolysis tests with original carbon-14 waste solution at lab-scale. We were able to demonstrate that electrochemical oxidation permits almost quantitative mineralization of the organic waste substances. The carbon dioxide released during electrolysis was completely fixed as solid calcium carbonate which is acceptable for final repository. An estimate shows that in comparison to conventional incineration a substantial decrease in the costs of treatment and repository can be expected. With regard to technical application further steps of development are necessary. (orig.)

  12. Studies on layer growth and interfaces on Ta-base thin layers by means of XPS; Untersuchungen zu Schichtwachstum und Grenzflaechen an Ta-basierten Duennschichten mittels XPS

    Energy Technology Data Exchange (ETDEWEB)

    Zier, M.

    2007-11-02

    In this thesis studies on the growth and on the formation of the interfaces of Ta and TaN layers on Si and SiO{sub 2} were performed. In the system TaN on SiO{sub 2} no reaction on the interface could be found. As the system with the mostly disturbed interface Ta on SiO{sub 2} was proved. Here a reduction of the SiO{sub 2} at simultaneous oxidation of the Ta was to be observed. Additionally tantalum silicide was formed to be considered concerning the bonding state as Ta{sub 5}Si{sub 3}, from which a double layer of a tantalum silicide and a tantalum suboxide resulted. A whole thickness of the double layer of above 1 nm resulted. In the system Ta on Si at the deposition of the film on the interface a tantalum silicide was formed to be characterized concerning the bonding state as TaSi{sub 2}. The thickness of the interlayer growed thereby up to 0.8 nm in form of islands. Finally in the system TaN on Si a silicon nitride formation during the deposition was observed, which was attributed to the insertion of adsorbed nitrogen from the sputtering atmosphere by recoil implantation of the sputtered Ta atoms. The silicon nitride interlayer growed thereby up to a thickness of 0.8 nm.

  13. Correlations of the chemical shift on fasly rotating biological solids by means of NMR spectroscopy; Korrelationen der chemischen Verschiebung an schnell rotierenden biologischen Festkoerpern mittels NMR-Spektroskopie

    Energy Technology Data Exchange (ETDEWEB)

    Herbst, Christian

    2010-04-27

    The basic aim of the thesis was the development and improvement of homo- and heteronuclear feedback sequences for the generation of correlation spectra of the chemical shift. In a first step the possibility of the acquisition of {sup 13}C-{sup 13} correlation spectra of the chemical shift by means of inversion pulses with low RF power factor was studied. Furthermore it was shown that broad-band phase-modulated inversion and universal rotational pulses can be constructed by means of global optimization procedures like the genetic algorithms under regardment of the available RF field strength. By inversion, universal rotational, and 360 pulses as starting values of the optimization efficient homonuclear CN{sub n}{sup {nu}} and RN{sub n}{sup {nu}} mixing sequences as well as heteronuclear RN{sub n}{sup {nu}{sub s},{nu}{sub k}} feedback sequences were generated. The satisfactory power of the numerically optimized sequences was shown by means of the simulation as well by means of correlation experiments of the chemical shift of L-histidine, L-arginine, and the (CUG){sub 97}-RNA. This thesis deals furthermore with the possibility to acquire simultaneously different signals with several receivers. By means of numerically optimized RN{sub n}{sup {nu}{sub s},{nu}{sub k}} pulse sequences both {sup 15}N-{sup 13}C and {sup 13}C-{sup 15}N correlation spectra were simultaneously generated. Furthermore it could be shown that the simultaneous acquisition of 3D-{sup 15}N-{sup 13}C-{sup 13}C and {sup 13}C-{sup 15}N-({sup 1}H)-{sup 1}H correlation spectra is possible. By this in only one measurement process resonance assignments can be met and studies of the global folding performed. A further application of several receivers is the simultaneous acquisition of CHHC, NHHN, NHHC, as well as CHHN spectra. By such experiments it is possible to characterize the hydrogen-bonding pattern and the glycosidic torsion angle {sup {chi}} in RNA. This was demonstrated by means of the (CUG){sub 97}-RNA. The simultaneous acquisition of all relevant crossing signals of the correlation spectra leads not only to an essential time saving, but is also necessary for the quantitative determination of {sup 1}H-{sup 1}H distances.

  14. New heating system for heaters-treaters and glycol regenerators using liquid or gaseous fuel. Neues Beheizungsverfahren von Heatern-Treatern und Glykolregeneratoren mittels fluessigen oder gasfoermigen Brennstoffen

    Energy Technology Data Exchange (ETDEWEB)

    Schmidtke, G.

    1990-12-01

    A new system for the heating of heaters-treaters and glycol regnerators is described. The main difference to the customary technique is that instead of an atmospheric gas burner, which uses the injector principle for drawing in gas, a compressed-air gas bruner with a blower is used. Burners of this type can be installed directly inside the flame tubes of the plants, so that flame arrestors with be unnecessary. Apart from its low noise, this combination technology has the further advantage of permitting near-stoichiometric operation in a wide control range. This will reduce the off-gas losses to a much lower level, as is illustrated by the dramtically lower off-gas values measured in the test phase. (orig.).

  15. Screening und Quantifizierung organischer Spurenstoffe mittels UPLC-HRMS:Entwicklung von Methoden und Anwendung zur Unterscheidung historischer und aktueller Spurenstoffe in einem ehemaligen Rieselfeld

    OpenAIRE

    Wode, Florian

    2014-01-01

    Aufgrund zunehmender Wasserknappheit gewinnt die Nutzung von gereinigtem Abwasser (Klarwasser), bezeichnet als Water Reuse, weltweit an Bedeutung. Neben herkömmlichen chemischen und mikrobiologischen Parametern spielen organische Spurenstoffe zunehmend eine Rolle bei der Beurteilung der Wasserqualität, die über mögliche Nutzungsformen entscheidet. In dieser Arbeit wurde die Spurenstoffbelastung in Grund- und Oberflächenwasser eines ehemaligen Rieselfeldgebietes untersucht, in dem seit 2005 Kl...

  16. Determination of Ra-223 in human excretion samples by means of α-spectrometry; Bestimmung von {sup 223}Ra in Ausscheidungsproben mittels α-Spektrometrie

    Energy Technology Data Exchange (ETDEWEB)

    Zoriy, M.V.; Froning, M.; Hill, P. [Forschungszentrum Juelich GmbH (Germany). Geschaeftsbereich Strahlenschutz und Sicherheit

    2015-07-01

    To ensure the safety of occupationally exposed person for possible incorporation of {sup 223}Ra during the handling with Alpharadin / Xofigo {sup registered}, the determination of {sup 223}Ra activity in its excretion sample (e.g, in a stool sample) might be of great importance. To assess the {sup 223}Ra activity in human faeces samples a new analytical method was developed in our laboratory. The determination is performed by means of grid-ionization a-spectrometry. After a relatively simple sample preparation procedure (usually within max. 6 hours) and the addition of an internal standard, a direct determination of {sup 223}Ra with the grid ionization chamber (GIK) is possible. The method was optimized and successfully tested. The procedure-related LOD for {sup 223}Ra in a 24-hour faeces sample was 0.1 Bq/Probe.

  17. Modern diagnostic assessment of the upper urinary tract using multislice CT urography; Moderne Diagnostik des oberen Harntraktes mittels Mehrschicht-CT-Urographie

    Energy Technology Data Exchange (ETDEWEB)

    Kemper, J.; Adam, G.; Nolte-Ernsting, C. [Klinik und Poliklinik fuer Diagnostische und Interventionelle Radiologie, Universitaetsklinikum Hamburg-Eppendorf (Germany)

    2006-11-15

    The advent of Multislice Computed Tomography (MSCT) has made evaluation of the entire urinary tract with high-resolution sections during a single breath-hold a reality. Acquisition of multiple thin overlapping slices provides excellent two-dimensional (2D) and three-dimensional (3D) reformations of the urinary tract. The concept of 'Multislice CT Urography (MSCTU)' has emerged from this technical improvement. As a result, a wide range of pathologies inside and outside the urinary tract can be identified. During the last several years, MSCTU has challenged intravenous urography (IVU) in the evaluation of urinary tract abnormalities. Compared with IVU, MSCT(U) is more sensitive and specific in the detection and characterization of a variety of urinary tract disorders, including renal masses and urolithiasis. The main advantage of IVU has been its ability to offer excellent delineation of kidney basin cup system and ureteral anatomy and to depict subtle uroepithelial abnormalities. MSCTU has already shown promising results for overcoming this challenge. Optimal opacification and distension appear to be an essential requirement for a thorough evaluation of the collecting system. Dedicated preparation strategies have been developed to meet these technical difficulties. The biggest disadvantage of MSCTU is the significant radiation exposure. For broad routine clinical application, there is still a need for dose reduction protocols despite the ongoing technical developments in MSCTU. In this article, we outline the different concepts of technical processing for MSCTU and summarize the current role of MSCTU in the evaluation of the upper urinary tract. (orig.)

  18. Fabrication and characterization of silicon nanowires by means of molecular beam epitaxy; Herstellung und Charakterisierung von Silizium-Nanodraehten mittels Molekularstrahlepitaxie

    Energy Technology Data Exchange (ETDEWEB)

    Schubert, Luise

    2007-06-19

    In this work, basic processes of silicon whisker growth were examined. For the first time, Si nanowhiskers were produced under UHV conditions by Molecular Beam Epitaxy (MBE) and characterized by different analysis methods afterwards. The existence of Au/Si droplets on a Si(111) substrate surface is a precondition of this growth method. Analyses of the temporal development of the Au/Si droplets during the whisker growth show a decrease of the number of small droplets resp. whiskers during the whisker growth with increasing growth time. This behaviour, i.e. the dissolution of smaller droplets/whiskers and the growth of larger ones in parallel can be explained by Ostwald ripenning. The diffusion-determined material transition of gold, which occurs during this process, is theoretically described by the Lifshitz-Slyozov-Wagner (LSW)-Theory. After this theory only whiskers grow which radii are larger than the critical radius. The whisker radii are temperature dependend whereas analogous whisker radii exist for identical growth times. Electron microscopy analysis show that all whiskers possess a hexagonal but no cylindrical habitus. The planes that form during the growth are crystallographic (111) planes. The growth of Si nanowhiskers under MBE conditions is determined by the Vapour Liquid Solid (VLS) mechanism and by surface diffusion of Si atoms. (orig.)

  19. Energy management in the low-voltage supply by decentralized decision. Concepts, algorithms, communication and simulation; Energiemanagement in der Niederspannungsversorgung mittels dezentraler Entscheidung. Konzept, Algorithmen, Kommunikation und Simulation

    Energy Technology Data Exchange (ETDEWEB)

    Nestle, David

    2008-07-01

    In this paper we present two key concepts for a future energy market with distributed electricity generation. First, we describe the energy management of distributed generators and loads with decentralized decision by bidirectional energy management interfaces. Second, we present a market platform supporting spontaneous trading by means of automated contract conclusion, innovative business models, and optimisation and controlling procedures for the demand as well as the supply side. (orig.)

  20. Das Ziel bestimmt die Mittel. Das Wirken Östen Undéns auf dem Weg zur schwedischen Neutralitätspolitik.

    Directory of Open Access Journals (Sweden)

    Peer Krumrey

    2009-12-01

    Full Text Available The Swedish policy of non-alliance aiming at neutrality in the event of war with all its contradictions and disputes continues to have an effect on societal debate in today’s Sweden. This article advocates a more accurate differentiation between historical processes and political assessments. It argues that this can be achieved by focussing on objectives set at that time as well as political outcomes resulting from the means chosen to achieve them rather than trying to compile moral benchmarks retrospectively. In order to exemplify this the article draws on the long-time Swedish foreign minister Östen Undén whose work is considered formative for Swedens foreign and security policy during the Cold War. It is stated that by using this approach it is possible to solve some of the prevailing contradictions and to demonstrate a higher degree of continuity.

  1. Zur Morphologie der physiologischen Foveae am Augenhintergrund von Greifvögeln und Eulen mittels Optischer Kohärenztomografie (OCT)

    OpenAIRE

    Schulze, Céline

    2016-01-01

    Die Optische Kohärenztomografie (OCT) ist eine neue Methode der Bilddarstellung, welche bereits erfolgreich in der humanmedizinischen Ophthalmologie etabliert wurde. Sie bietet die Möglichkeit, den Aufbau und die Morphologie der Retina in Querschnitten darzustellen und dies nicht-invasiv, kontaktfrei und in vivo in annähernd histologischer Auflösung. In der aviären Ophthalmologie wurde die OCT bisher kaum angewendet. Das Ziel der vorliegenden Arbeit war es daher, die OCT als ein geeignete...

  2. Detection of microbial volatile organic compounds (MVOC) by means of ion mobility spectroscopy (IMS); Detektion leicht fluechtiger organischer Verbindungen mikrobiellen Ursprungs (MVOC) mittels Ionenmobilitaetsspektrometrie (IMS)

    Energy Technology Data Exchange (ETDEWEB)

    Tiebe, Carlo

    2010-07-01

    Traces of microbial volatile organic compounds (MVOCs) can indicate the growth of moulds in the indoor air. The application of ion mobility spectrometry (IMS) is a very promising method for the detection of these MVOCs due to its high sensitivity. A mobile IMS device was tested to use this analytical-chemical method for in situ indoor air diagnostics. The first part of this work describes the test gas generation of 14 MVOCs in the laboratory. The test gases were produced by preparation of permeation procedures. Due to the MVOCs test gases IMS parameters like reduced mobility (K{sub 0}), relative drift time (t{sub rd}), the concentration dependency of MVOCs signals were determined and the limit of detection (LOD) was calculated. The LODs are in the range of 2 to 192 {mu}g m{sup -3} (1 to 51 ppb{sub V}). In the second part of this manuscript seven different mould species were cultivated on nutrient media and their MVOCs emissions were explored. It was found out, that the MVOCs emissions of moulds have a dependency of species and of their cultivation time. These results are confirmed by principal component analysis (PCA). The identification of these MVOCs was performed by test-related GC-MS analysis and approved these results. The MVOCs emissions were explored in the cultivation of mould mixtures on three different building materials. The IMS-results were interpreted chemo metrically by PCA. It was possible to find different emission patterns of cultivated moulds on building materials without an identification of the MVOCs inside the emission chamber. In 27 field trials of different indoor environments (rooms) the IMS was tested to detect MVOCs. In 59 % of the cases a positive correlation is determined between visible mould-infested rooms and the detected MVOCs by IMS. (orig.)

  3. Vermittlung von Naturheilverfahren in der Veterinärmedizin mittels E-Learning [Teaching methods of alternative therapy in veterinary medicine via e-learning

    Directory of Open Access Journals (Sweden)

    Fidelak, Christian

    2008-11-01

    Full Text Available [english] The Free University’s Veterinary Clinic of Reproduction in the Department of Veterinary Medicine, Berlin, has been offering courses on alternative and complementary veterinary medicine to its students for several years. Due to time constraints and shortages in teaching staff, it has not been possible to satisfy student demand for instruction in these areas. To provide more detailed information as well as more opportunities for discussion and practica, subject area courses were modified in two steps. Initially, blended learning was implemented to include e-learning and in-class formats of instruction. Subsequently, an entire block of courses offered were transferred to e-learning format. Students may now voluntarily register for the e-learning course entitled “Introduction of alternative and complementary veterinary medicine” via the Internet and learn the basic principles of homoeopathy, herbal medicine, acupuncture and other alternative methods in veterinary medicine. After passing this basic course, blended learning courses enable advanced students to learn more about fundamentals of methods in greater detail as well as to perform practica with animal subjects. The evaluation of these courses showed that students rated e-learning to be a reasonable addendum to in-class instruction. More than two thirds of the students recommended an increased integration of e-learning into veterinary education. [german] Die Tierklinik für Fortpflanzung in Berlin bietet den Studierenden der Veterinärmedizin seit einigen Semestern Wahlpflichtkurse zu den Naturheilverfahren an. Der enormen Nachfrage seitens der Studierenden standen personelle und zeitliche Begrenzungen des Lehrpersonals gegenüber. Um den Interessenten dennoch umfangreiche Informationen zu bieten sowie Freiräume für Diskussionen und praktische Übungen zu schaffen, wurde das Ausbildungsangebot in zwei Projektphasen ausgebaut. Zunächst wurde dabei die Methode des Blended-Learning genutzt. Anschließend wurde ein Teil des Kursangebotes komplett auf E-Learning umgestellt. Der Wahlpflichtkurs „Einführung in die Naturheilverfahren“ kann seither von den Studierenden vollständig über das Internet bearbeitet werden. Dieser Kurs behandelt die theoretischen Grundlagen von Homöopathie, Phytotherapie, Akupunktur und einigen weiteren Methoden. In Aufbaukursen werden neben einer Vertiefung der Grundlagen umfangreiche praktische Übungen durchgeführt. Die Evaluationsergebnisse belegen, dass die Studierenden E-Learning als sinnvolle Ergänzung der herkömmlichen Lehrmethoden betrachten. Zudem befürworten mehr als zwei Drittel der Studierenden eine vermehrte Einbindung von E-Learning in die Ausbildung.

  4. Using solar heat to enhance waste-heat use; Solarthermische Abwaermenutzung; Aufwertung von Abwaerme mittels Solarthermie zur Erzeugung hochwertiger Prozessenergie - Schlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, R. [BMG Engineering AG, Schlieren (Switzerland); Luzzi, A.; Marty, H. [HSR, Hochschule fuer Technik, SPF Institut fuer Solartechnik, Rapperswil (Switzerland)

    2008-12-15

    This final report for Swiss Federal Office of Energy (SFOE) presents the work done in a project involving the use of solar heat to enhance the use of waste heat at a chemical plant in Nyon, Switzerland. On the basis of a study carried out in 2006/2007, which looked at the reduction of process energy demand of a production site where an agent is produced in batch operation, possibilities for the recovery of waste heat were identified. The relatively low temperatures of the existing waste heat flows have, however, complicated its efficient use. This reflects a problem with waste heat use in industrial processes that can often be observed. Due to the sunny location in Nyon, a concept using solar energy to increase the temperature level of this waste heat has been developed. The objective of this analysis was the technical and economical assessment of such an installation and its transferability to other sites. Variants are presented and their economic viability is discussed.

  5. 3D characterisation of the gaseous and liquid phase using laser-induced exciplex fluorescence (LIEF) tomography; Dreidimensionale Charakterisierung der Gas- und Fluessigphase mittels laserinduzierter Exciplexfluoreszenz (LIEF) Tomografie

    Energy Technology Data Exchange (ETDEWEB)

    Rogler, P.; Grzeszik, R.; Arndt, S. [Robert Bosch GmbH, Stuttgart (Germany); Waidmann, C. [Fachhochschule Aalen (Germany); Aigner, M. [DLR, Stuttgart (Germany). Inst. fuer Verbrennungstechnik

    2007-07-01

    The quality of mixture formation in gasoline engines has a significant influence on combustion, emissions and mileage. The measurement technique used for mixture formation analysis of both liquid and vapor phase is laser induced exciplex fluorescence (LIEF), where the aromatics TMPD and naphthalene are added to a non-fluorescing model fuel free of aromatic compounds. For spatially high-resolved measurements of liquid and vapor phase this technique was extended from planar to volume information via tomography. This new approach requires fundamental studies of tracer behavior and new evaluation algorithms for reliable signal interpretation of fluid dynamics in sprays. Using this measurement technique GDI sprays are investigated at a typical stratified engine operation point at part load. For the different injector types, e.g. multi hole and annular orifice injector, an optimal illumination is crucial. With the collected data the spray volume can be calculated, mixture homogeneity can be evaluated and, using a few assumptions, the air/fuel ratio {lambda} can be computed. (orig.)

  6. A water legislation evaluation of the unconventional production of natural gas by means of fracking; Wasserrechtliche Bewertung der unkonventionellen Erdgasfoerderung mittels Fracking

    Energy Technology Data Exchange (ETDEWEB)

    Rossnagel, Alexander; Polzer, Andreas [Kassel Univ. (Germany). Kompetenzzentrum fuer Klimaschutz und Klimaanpassung (CliMA); Hentschel, Anja [Kassel Univ. (Germany). Inst. fuer Wirtschaftsrecht (IWR)

    2012-07-01

    Fracking causes underground and aboveground risks for ground water. Under this aspect, the authors of the contribution report on regulation concepts and instruments of the water protection law in order to manage the risks. The authors also describe how these regulations have to be understood in order to manage these underground and aboveground risks.

  7. Determination of polycyclic aromatic hydrocarbons in deposited waste using GC-MSD. Bestimmung von polycyclischen aromatischen Kohlenwasserstoffen in Deponiegut mittels GC-MSD

    Energy Technology Data Exchange (ETDEWEB)

    Treffert, U. (chemlab, Gesellschaft fuer Analytik und Umweltberatung mbH, Bensheim (Germany). Abt. ' ' Organische Analytik' ' ); Kolb, M. (Fachhochschule Aalen (Germany)); Stoerk, H. (chemlab, Gesellschaft fuer Analytik und Umweltberatung mbH, Bensheim (Germany))

    1999-06-01

    The articel describes an analysis method for the determination of 16 polycyclic aromatic hydrocarbons in deposited waste. The single steps are described very detailed: sample preparation by extraction, evaporation, flash-chromatography (Al[sub 2]O[sub 3]), quantitative analysis by GC-MSD. (SR)

  8. Sealing of ceramic SOFC-components with glass seals; Fuegen von keramischen Komponenten der Hochtemperatur-Brennstoffzellen mittels Glas- und Glaskeramikloten

    Energy Technology Data Exchange (ETDEWEB)

    Schillig, Cora

    2012-07-10

    The solid oxide fuel cell (SOFC) converts chemical energy of a fuel directly into electrical energy. However, for the implementation of SOFC-technology in competition to conventional power plants costs have to be reduced. The use of an alternative tubular cell design without closed end would allow reducing costs during cell manufacturing. However, this change in design makes a gastight sealing inside the generator near the gas inlet necessary. Different ceramic materials with varying coefficients of thermal expansion have to be sealed gastight and electrical insulating at temperatures between 850 C and 1000 C to prevent the gases from mixing and an electrical shortcut between the cells. This work comprises analysis of commercially available glass and glass-ceramic systems manufactured by Schott Electronic Packaging, Areva T and D and Ferro Corporation. Additionally new developed sealing glass and glass-ceramic systems were investigated and all systems were characterized fundamentally for the use as sealing material in SOFC generators. Therefore different test assemblies and series were conducted. Essential characteristics of a suitable sealing system are a thermal expansion coefficient between 9,5 and 12 . 10{sup -6}K{sup -1}, a viscosity in the range between 10{sup 4} to 10{sup 6} dPa{sup *}s and a wetting angle smaller than 90 during the sealing process. Also unwanted chemical side reactions between the sealing partners must be prevented, because a change in the phase composition or the creation of new phases in the sealing material could endanger the stability of the seal. Heat cycles, particularly those during generator operation, cause deterioration of the sealing material and subsequent reduction in its ability to prevent mixing of the gases. Sealant leaks can drastically impact efficiency of the generator. In order to ensure optimum operation low leak rates around 2,3 . 10{sup -4} mbar l/sec/cm{sup 2} must be maintained. Especially glass and glass-ceramics of the following systems CaO-MgO-Al{sub 2}O{sub 3}-SiO{sub 2} and BaO-Al{sub 2}O{sub 3}-SiO{sub 2}-B{sub 2}O{sub 3} show promising results. Special test assemblies for the determination of electrical conductivity and leak rate are set up for characterization. Finally, different selected sealing systems are tested under operating conditions in a bench-scale stack. Inside the SOFC-generator an additional gastight seal is needed between several dense and porous Al{sub 2}O{sub 3}-ceramic parts used for the gas supply, before the gas hits the fuel cells. Twenty four dense tubes with a length of 1 m and a porous plate were sealed as proof of concept with a seal based on the following oxides Al{sub 2}O{sub 3}-SiO{sub 2}-K{sub 2}O-CaO and with a thermal expansion coefficient between 8 and 9 . 10{sup -6}K{sup -1}.

  9. Flexible injection control for fuel consumption and emission reduction in passenger cars?; Flexible Einspritzverlaufsformung: Auch bei PKW-Dieselmotoren ein wirkungsvolles Mittel zur Reduzierung von Verbrauch und Schadstoffemissionen?

    Energy Technology Data Exchange (ETDEWEB)

    Laumen, H.J.; Koerfer, T.; Lamping, M. [FEV Motorentechnik GmbH, Aachen (Germany); Pischinger, S.; Schmuecker, K.J. [RWTH Aachen (Germany). Lehrstuhl fuer Verbrennungskraftmaschinen

    2007-07-01

    In the recent decade the Diesel injection technology has been modified significantly. The old cam driven injection systems have been replaced nearly completely by modern Common Rail systems which enable a significantly higher degree of freedom especially with respect to multi-injection strategies and exhaust aftertreatment demands. Nevertheless, cam driven injection systems offered special characteristics which were favorable regarding fuel consumption and emissions. Due to the much higher nozzle opening and closing velocity, the seat throttling effects are widely reduced. Furthermore the fuel injection rate during ignition delay is smaller, compared to today's Common Rail systems. A new type of a piezoelectric Common Rail injector for passenger car engines, called FIRST (Flexible Injection Rate Shaping Tool) is described in this article, which combines both, the flexibility of modern Common Rail injectors as well as the benefits of cam driven injection systems regarding reduced seat throttling effects. Additionally flexible injection rate shaping is enabled by forming the slope of the actuator voltage. Both, the hydraulic behavior and also the engine performance with the new injector are presented in comparison to conventional injectors. The FIRST injector offers a benefit of 20% in PM and CO emission with constant NO{sub x} emission and reduced fuel consumption at part load as a result of the reduced seat throttling. By an optimization of the injection rate shape, the NO{sub x} emissions can be reduced by 40% at constant fuel consumption and PM emissions and without deterioration of NVH level. (orig.)

  10. Quantitative imaging of magnetic nanoparticles by magneto-relaxometric tomography for biomedical applications; Quantitative Bildgebung magnetischer Nanopartikel mittels magnetrelaxometrischer Tomographie fuer biomedizinische Anwendungen

    Energy Technology Data Exchange (ETDEWEB)

    Liebl, Maik

    2016-11-18

    Current biomedical research focuses on the development of novel biomedical applications based on magnetic nanoparticles (MNPs), e.g. for local cancer treatment. These therapy approaches employ MNPs as remotely controlled drug carriers or local heat generators. Since location and quantity of MNPs determine drug enrichment and heat production, quantitative knowledge of the MNP distribution inside a body is essential for the development and success of these therapies. Magnetorelaxometry (MRX) is capable to provide such quantitative information based on the specific response of the MNPs after switching-off an applied magnetic field. Applying a uniform (homogeneous) magnetic field to a MNP distribution and measuring the MNP response by multiple sensors at different locations allows for spatially resolved MNP quantification. However, to reconstruct the MNP distribution from this spatially resolved MRX data, an ill posed inverse problem has to be solved. So far, the solution of this problem was stabilized incorporating a-priori knowledge in the forward model, e.g. by setting priors on the vertical position of the distribution using a 2D reconstruction grid or setting priors on the number and geometry of the MNP sources inside the body. MRX tomography represents a novel approach for quantitative 3D imaging of MNPs, where the inverse solution is stabilized by a series of MRX measurements. In MRX tomography, only parts of the MNP distribution are sequentially magnetized by the use of inhomogeneous magnetic fields. Each magnetizing is followed by detection of the response of the corresponding part of the distribution by multiple sensors. The 3D reconstruction of the MNP distribution is then accomplished by a common evaluation of the distinct MRX measurement series. In this thesis the first experimental setup for MRX tomography was developed for quantitative 3D imaging of biomedical MNP distributions. It is based on a multi-channel magnetizing unit which has been engineered to generate a time-multiplexed sequence of precise magnetic fields for spatially constrained magnetizing of the MNP distribution. The unit has been integrated into a sensor system containing 304 superconducting quantum interference devices (SQUIDs) used for the spatially resolved detection of the MNP responses after each magnetizing. Furthermore, for evaluation of MRX tomography MNP phantoms reflecting the MNP distribution after magnetic drug targeting therapy in animals were designed and implemented. Using these phantoms, MNP distributions with clinical MNP doses in the milligram range could be quantitatively reconstructed by MRX tomography within a field of view up to 600 cm³ and a spatial resolution of a few cubic centimeters. The deviation between the quantified and nominal MNP amount was found to be below 10%. With the present experimental setup MRX tomography measurements of a complete MNP distribution were performed within the typical anesthesia time interval of a few minutes prevailing in preclinical animal studies. By implementing advanced magnetizing sequences this measurement time of the MRX tomography setup could be reduced to below 30 s. Finally, using the same MRX tomography setup a binding state specific quantitative imaging of MNP distributions was achieved by incorporating the temporal MNP relaxation behavior into the reconstruction. Hence, MRX tomography has the potential to image the influence of the local biological environment on the physical properties of the MNPs. The presented MRX tomography setup allows for sensitive and specific spatially resolved 3D quantification of MNPs in small animals. This represents an important step towards the development of a clinical imaging tool for the control and assessment of MNP based cancer treatments. Moreover, by adjusting the excitation coils the field of view could be easily enlarged making MRX tomography quite conceivable for human application.

  11. Functional estimation of kidneys after extracorporeal shock wave therapy (ESWL) by clearance. Funktionsbeurteilung der Nieren nach extrakorporaler Stosswellenlithotripsie (ESWL) mittels Nieren-Clearance

    Energy Technology Data Exchange (ETDEWEB)

    Sydow, K.; Kirschner, P.; Brien, G.; Buchali, K.; Frenzel, R. (Humboldt-Universitaet, Berlin (Germany). Medizinische Fakultaet)

    1991-10-01

    35 patients were scintiscanned with 99m-Tc-DTPA to determine the effects of extracorporeal shock waves used to desintegrate renal concrements may have on the patients renal function. The therapy was conducted using a standard Lithostar unit (Siemens) (20 patients) and an additional overtable module (15 patients). Functional scintigraphy was performed using a gamma camera before lithotripsy, and on the first day after it. Further control investigations were performed one or two weeks later and two till six months later. In both groups most of the patients developed temporary restrictions in renal function, some of them irreversible restrictions. Functional losses were found to be less severe with the use of the overtable module than with the standard Lithostar unit. (orig.).

  12. Kurz-, mittel- und langfristige Effekte einer Schulung für Patienten mit chronisch entzündlichen Darmerkrankungen auf krankheitsbezogene Ängste und Gesundheitskompetenzen

    OpenAIRE

    Berding, Anja

    2017-01-01

    Menschen mit chronisch entzündlichen Darmerkrankungen (CED) leiden unter vielfältigen körperlichen und psychosozialen Einschränkungen. Wie auch bei anderen chronischen Erkrankungen könnten Patientenschulungen ihr psychisches Befinden verbessern (z.B. De Ridder & Schreurs, 2001; Faller, Reusch & Meng, 2011a; Küver, Becker & Ludt, 2008; Schüssler, 1998; Warsi, Wang, LaValley, Avorn & Solomon, 2004). Für CED liegen jedoch nur wenige Schulungsevaluationen vor (z.B. Bregenzer et al., 2005; Mussell...

  13. Trace analysis of actinides in the environment using resonance ionization mass spectrometry; Spurenanalyse von Aktiniden in der Umwelt mittels Resonanzionisations-Massenspektrometrie

    Energy Technology Data Exchange (ETDEWEB)

    Raeder, Sebastian

    2011-04-12

    In this work the resonant ionization of neutral atoms using laser radiation was applied and optimized for ultra-trace analysis of the actinides thorium, uranium, neptunium and plutonium. The sensitive detection of these actinides is a challange for the monitoring and quantification of radioactive releases from nuclear facilities. Using resonance ionization spectroscopy combined with a newly developed quadrupole-mass-spectrometer, numerous energy levels in the atomic structure of these actinides could be identified. With this knowledge efficient excitation schemes for the mentioned actinides could be identified and characterised. The applied in-source-ionization ensures for a high detection efficiency due to the good overlap of laser radiation with the atomic beam and allows therefore for a low sample consumption which is required for the analysis of radio nuclides. The selective excitation processes in the resonant ionization method supresses unwanted contaminations and was optimized for analytical detection of ultra-trace amounts in environmental samples as well as for determination of isotopic compositions. The efficient in-source-ionization combined with high power pulsed laser radiation allows for detections efficiency up to 1%. For plutonium detection limits in the range of 10{sup 4}-10{sup 5} atoms could be demonstrated for synthetic samples as well as for first environmental samples. The usage of narrow bandwidth continuous wave lasers in combination with a transversal overlap of the laser radiation and the free propagating atomic beam enable for resolving individual isotopic shifts of the resonant transitions. This results in a high selectivity against dominant neighboring isotopes but with a significant loss in detection efficiency. For the ultra-trace isotope {sup 236}U a detection limit down to 10{sup -9} for the isotope ratio N ({sup 236}U)/N ({sup 238}U) could be determined.

  14. A numerical calculation method for flow discretisation in complex geometry with body-fitted grids; Rechenverfahren zur Diskretisierung von Stroemungen in komplexer Geometrie mittels koerperangepasster Gitter

    Energy Technology Data Exchange (ETDEWEB)

    Jin, X.

    2001-04-01

    A numerical calculation method basing on body fitted grids is developed in this work for computational fluid dynamics in complex geometry. The method solves the conservation equations in a general nonorthogonal coordinate system which matches the curvilinear boundary. The nonorthogonal, patched grid is generated by a grid generator which solves algebraic equations. By means of an interface its geometrical data can be used by this method. The conservation equations are transformed from the Cartesian system to a general curvilinear system keeping the physical Cartesian velocity components as dependent variables. Using a staggered arrangement of variables, the three Cartesian velocity components are defined on every cell surface. Thus the coupling between pressure and velocity is ensured, and numerical oscillations are avoided. The contravariant velocity for calculating mass flux on one cell surface is resulting from dependent Cartesian velocity components. After the discretisation and linear interpolation, a three dimensional 19-point pressure equation is found. Using the explicit treatment for cross-derivative terms, it reduces to the usual 7-point equation. Under the same data and process structure, this method is compatible with the code FLUTAN using Cartesian coordinates. In order to verify this method, several laminar flows are simulated in orthogonal grids at tilted space directions and in nonorthogonal grids with variations of cell angles. The simulated flow types are considered like various duct flows, transient heat conduction, natural convection in a chimney and natural convection in cavities. Their results achieve very good agreement with analytical solutions or empirical data. Convergence for highly nonorthogonal grids is obtained. After the successful validation of this method, it is applied for a reactor safety case. A transient natural convection flow for an optional sump cooling concept SUCO is simulated. The numerical result is comparable with the experiment. To improve the cooling concept, a further simulation is carried out for a modified geometry with a slightly inclined cooler. This is difficult to be done in the Cartesian coordinate system. The result gained with the new discretisation method demonstrates an increase in the convection velocities and thus an improved cooling capability for the core melt. The method significantly expands the application range of the numerical simulation from simple geometry to arbitrary geometry. (orig.) [German] Zur Loesung staendig komplizierterer Stroemungsprobleme nimmt die Anforderung an die erfassbare Rechengeometrie zu. Fuer die Darstellung einer komplexen Geometrie sind kartesische oder zylindrische Koordinatensysteme, mit denen das Rechenprogramm FLUTAN arbeitet, allein nicht mehr ausreichend. Es besteht deshalb die Notwendigkeit von Stroemungsberechnungen im allgemeinen Koordinatensystem, damit die numerische Simulation in beliebiger, zumindest jedoch krummlinig berandeter Geometrie durchgefuehrt werden kann. Im Rahmen dieser Arbeit wird ein numerisches Rechenverfahren fuer die Diskretisierung von Stroemungen in einem koerperangepassten Gitter entwickelt. Das Rechenverfahren wird durch die dreidimensionale Koordinatentransformation fuer die Impulsgleichungen, die Kontinuitaets- und Energiegleichung im versetzten nichtorthogonalen Gitter erstellt. Aufgrund der Anschaulichkeit und der leichteren Diskretisierung der transformierten Gleichungen werden kartesische Geschwindigkeitskomponenten eingesetzt. Die Definition aller drei kartesischen Geschwindigkeitskomponenten an jeder Oberflaeche eines Kontrollvolumens sichert die enge Druck-Geschwindigkeit-Kopplung auch auf stark krummlinigen Gittern. Nach der Diskretisierung und der linearen Interpolation erscheinen insgesamt 19 unbekannte Druckknoten in der transformierten Druckgleichung fuer drei Dimensionen. Durch die explizite Behandlung der querabgeleiteten Terme ergibt sich wieder der uebliche 7-Punkt-Gleichungstyp, der mit den existierenden Solvern geloest werden kann. Hierbei koennen die Randbedingungen direkt an den gekruemmten Raendern definiert werden. Das Rechenverfahren dieser Arbeit stellt einen Fortschritt dar gegenueber den bisherigen Verfahren fuer eine versetzte Anordnung. Das Rechenverfahren ist durch eine gemeinsame Daten- und Ablaufstruktur mit FLUTAN kompatibel und in diesem Programm realisiert. (orig.)

  15. Control of nitrification and denitrification by means of oxygen measurement in activated sludge; Steuerung der Nitrifikation und Denitrifikation mittels Sauerstoffmessung im Belebungsbecken

    Energy Technology Data Exchange (ETDEWEB)

    Svardal, K.; Kroiss, H.

    1997-12-31

    As the simulation results show, controlling nitrification/denitrification by means of the oxygen content is a very effective method. Its big advantage is that the concentration of O{sub 2} can be very reliably measured. In comparison with online analysis units, O{sub 2} probes demand little maintenance and are inexpensive; so, each measuring point can be supplied with its own probe. O{sub 2} measurement is indispensable also with other control strategies. It would make sense, at least at larger plants, to monitor additionally the concentration of ammonium, a parameter which makes for a higher safety margin. (orig./SR) [Deutsch] Die Simulationsergebnisse zeigen, dass die Steuerung der Nitrifikation/Denitrifikation nach dem Sauerstoffgehalt sehr gute Resultate ergibt. Der grosse Vorteil dieser Art der Steuerung besteht darin, dass die O{sub 2}-Konzentration sich sehr zuverlaessig messen laesst. O{sub 2}-Sonden sind im Vergleich zu online-Analysatoren wartungsarm und preisguenstig, so dass auch eine reduntante Ausfuehrung jeder Messstelle vertretbar ist. Auf die O{sub 2}-Messung kann auch bei anderen Steuerstrategien nicht verzichtet werden. Eine sinnvolle Ergaenzung waere zumindest bei groesseren Anlagen eine Ueberwachung der Ammoniumkonzentration wobei dieser Messwert vor allen Dingen der Sicherheit dient. (orig./SR)

  16. Recycling of rare earths from Hg-containing fluorescent lamp scraps by solid state chlorination; Rueckgewinnung Seltener Erden aus quecksilberbelasteten Leuchtstoffen mittels Feststoffchlorierung

    Energy Technology Data Exchange (ETDEWEB)

    Lorenz, Tom; Froehlich, Peter; Bertau, Martin [TU Bergakademie Freiberg (Germany); Golon, Katja [FNE Entsorgungsdienste GmbH, Freiberg (Germany)

    2015-10-15

    Solid state chlorination with NH{sub 4}Cl comprises a method for rare earth recycling apart from pyro- or hydrometallurgical strategies. The examined partially Hg-containing fluorescent lamp scraps are rich in rare earths like La, Ce, Tb and Gd, but especially in Y and Eu. By mixing with NH{sub 4}Cl and heating up to NH{sub 4}Cl decomposition temperature in a sublimation reactor, Y and Eu could be transferred selectively into their respective metal chlorides with high yields. The yield and selectivity depend on temperature and the ratio of NH{sub 4}Cl to fluorescent lamp scraps, which were varied systematically.

  17. Future prospects of the brown coal of central and east Germany in the all-German energy industry. Perspektive der mittel- und ostdeutschen Braunkohle in der gesamtdeutschen Energiewirtschaft

    Energy Technology Data Exchange (ETDEWEB)

    Milojcic, G

    1991-04-01

    Against a background of different basic conditions the energy industry in the former German Democratic Republic during the last 30 years underwent an entirely different development to that which occurred in the former Federal Republic of Germany. In the Federal Republic, oriented to a free market system, a structural change took place from the 1960s onwards, that is to say, away from solid fuels and towards a mixed energy utilization, in which mineral oil and natural gas in particular play a significant part. The principal market for coal, especially brown coal, is the important power generation sector. The German Democratic Republik, on the other hand, in keeping with its autarchic energy policy relied on the only source of energy available in large quantities, namely brown coal. The reason for this lay in the fact that the system made it impossible to participate in an international exchange of commidities. As a result of the ton-quota ideology and inefficiency in all sectors of energy winning, conversion and utilization the consumption both of primary energy and also of electricity in the former German Democratic Republic was high compared to that in the Federal Republic, and this in spite of the fact that the per capita economic strength was less than half that of the Federal Republic. Two changes are likely to occur in future. On the one hand, a medium-term mixed energy utilization will develop in the primary energy sector, as has been the case in the Federal Republic. On the other hand, it can be assumed that simultaneously with this development consumption will tend to decrease. As in the Federal Republic, the future prospect to brown coal, which has hitherto played a dominating role, will in the first place lie in its utilization in conjunction with the power industry and only secondarily on the thermal energy market. (orig.).

  18. Potent clones. Efficiency of phytoremediation by means of willow family on the status of heavy metals; Potente Klone. Wirkung der Phytoremediation mittels Weidengewaechsen auf den Schwermetallstatus

    Energy Technology Data Exchange (ETDEWEB)

    Fibian, Kurt D. [Rostock Univ. (Germany). Fachgebiet Pflanzenernaehrung; Gombler, Willy; Gruessing, Edgar; Janssen-Weets, Sybille; Schlaak, Michael [Fachhochschule Emden-Leer, Emden (Germany). Inst. fuer Umwelttechnik-EUTEC

    2010-11-15

    The contents of cadmium, copper and zinc in a polluted substrate (harbour silt) were determined by means of fractionated extraction. In a pot attempt, four willow clones were cultivated on this substrate. After a test period of three years the changes in the individual fractions of heavy metal were determined. At the same time, the remove capacity of the test pastures being relevant for the process of phytoextraction were determined by means of the content of heavy metals of the aboveground plant organs and its dry weight. The results show that two of the examined pasture clones clearly are better suitable than poplars and corn, in order to remove in particular cadmium and zinc from the soil by means of phytoremediation.

  19. Radiologic diagnostics of dementia; Radiologische Demenzdiagnostik

    Energy Technology Data Exchange (ETDEWEB)

    Essig, M. [Radiologie, Deutsches Krebsforschungszentrum Heidelberg (Germany); Radiologie, Deutsches Krebsforschungszentrum Heidelberg, Im Neuenheimer Feld 280, 69120, Heidelberg (Germany); Schoenberg, S.O. [Institut fuer klinische Radiologie, Ludwig-Maximilians-Universitaet Muenchen (Germany)

    2003-07-01

    Dementia is one of the most common diseases in the elderly population and is getting more and more important with the ageing of the population. A radiologic structural examination with CT or MRI is meanwhile a standard procedure in the diagnostic work up of patients with dementia syndrome. Radiology enables an early diagnosis and a differential diagnosis between different causes of dementia. Because structural changes occur only late in the disease process, a more detailed structural analysis using volumetric techniques or the use of functional imaging techniques is mandatory. These days, structural imaging uses MRI which enables to detect early atrophic changes at the medial temporal lobe with focus on the amygdala hippocampal complex. These changes are also present in the normal ageing process. In patients with Alzheimer's disease, however, they are more rapid and more pronounced. The use of functional imaging methods such as perfusion MRI, diffusion MRI or fMRI allow new insights into the pathophysiologic changes of dementia. The article gives an overview of the current status of structural imaging and an outlook into the potential of functional imaging methods. Detailed results of structural and functional imaging are presented in other articles of this issue. (orig.) [German] Demenzielle Syndrome gehoeren zu den haeufigsten Erkrankungen im hoeheren Lebensalter und werden mit einer Zunahme der Ueberalterung in der Bevoelkerung volkswirtschaftlich immer bedeutender. Die radiologische Untersuchung mittels struktureller CT oder MRT gehoert mittlerweile zur Standardabklaerung jeder demenziellen Symptomatik. Sie dient der Frueherkennung und der Differenzialdiagnostik der verschiedenen Ursachen einer Demenz. Dies gilt insbesondere in Hinblick auf zu erwartende und bereits vorhandene Therapiemoeglichkeiten. Da jedoch strukturelle Veraenderungen erst relativ spaet im Fortschreiten der Erkrankung visualisiert werden koennen, sind detaillierte strukturelle

  20. MR spectroscopy in dementia; MR-Spektroskopie bei Demenz

    Energy Technology Data Exchange (ETDEWEB)

    Hauser, T.; Gerigk, L.; Giesel, F.; Schuster, L.; Essig, M. [Deutsches Krebsforschungszentrum (DKFZ) Heidelberg, Abteilung E010, Radiologie, Heidelberg (Germany)

    2010-09-15

    With an increasingly aging population we are faced with the problem of an increasing number of dementia patients. In addition to clinical, neuropsychological and laboratory procedures, MRI plays an important role in the early diagnosis of dementia. In addition to various morphological changes functional changes can also help in the diagnosis and differential diagnosis of dementia. Overall the diagnosis of dementia can be improved by using parameters from MR spectroscopy. This article focuses on MR spectroscopic changes in the physiological aging process as well as on changes in mild cognitive impairment a precursor of Alzheimer's dementia, in Alzheimer's dementia, frontotemporal dementia, vascular dementia and Lewy body dementia. (orig.) [German] Angesichts einer immer aelter werdenden Bevoelkerung sind wir mit dem Problem einer zunehmenden Zahl an Demenzerkrankungen konfrontiert. Neben klinischen, neuropsychologischen und laborchemischen Verfahren spielt die MRT zur Fruehdiagnostik einer Demenz eine wichtige Rolle. Morphologische Veraenderungen wie auch verschiedene funktionelle Verfahren helfen bei der Diagnostik und Differenzialdiagnostik einer Demenz. Insgesamt kann mittels MR-spektroskopischer Parameter die Diagnostik einer Demenz verbessert werden. In diesem Artikel soll auf MR-spektroskopische Veraenderungen im Rahmen des physiologischen Alterungsprozesses eingegangen werden. Ferner werden speziell Veraenderungen bei leichter kognitiver Beeintraechtigung, einer Vorform der Alzheimer-Demenz, bei Alzheimer-, frontotemporaler, vaskulaerer und Lewy-Koerper-Demenz eroertert. (orig.)

  1. Pretherapeutic and posttherapeutic laryngeal imaging; Prae- und posttherapeutische Larynxbildgebung

    Energy Technology Data Exchange (ETDEWEB)

    Becker, M.; Burkhardt, K.; Allal, A.S.; Dulguerov, P.; Ratib, O.; Becker, C.D. [Hopitaux Universitaires de Geneve, Abteilung fuer Hals-Nasen-Ohren-Radiologie, Geneve (Switzerland)

    2009-01-15

    endoskopischer Biopsie) beigeordnet und ergaenzen diese komplementaer. Eine sehr genaue Kenntnis der submukoesen Tumorausbreitungswege, der diagnostischen Zeichen der Tumorinfiltration und deren Konsequenzen fuer Stadieneinteilung und Therapie sind unentbehrlich fuer die Interpretation von CT-, MRT- und PET-CT-Bildern. Sowohl CT als auch MRT sind hochsensitive Untersuchungen zum Nachweis der neoplastischen Infiltration des praeepi- und paraglottischen Raums, der Subglottis und des Knorpels. Die Spezifitaet ist jedoch mit beiden Methoden weniger hoch als zunaechst erwartet, wodurch eine Tendenz zum Ueberschaetzen der Tumorausbreitung resultiert. Neuere Untersuchungen haben jedoch gezeigt, dass die Spezifitaet der MRT mittels Anwendung neuer diagnostischer Kriterien signifikant verbessert werden kann, da eine Unterscheidung zwischen Tumor und peritumoraler Entzuendung in vielen Faellen moeglich ist. Der sehr hohe negative Vorhersagewert der beiden Schnittbildverfahren ist aus klinischer Sicht wichtig, da er es ermoeglicht, die neoplastische Knorpelinfiltration auszuschliessen. Beide Methoden verbessern signifikant die praetherapeutische Stagingtreffsicherheit, wenn sie zusaetzlich zur Endoskopie eingesetzt werden. Bei submukoesen Tumoren liefern sowohl CT als auch MRT wertvolle Hinweise auf eine moegliche Aetiologie, auf das Ausmass des submukoesen Wachstums und die geeignete Biopsiestelle. Sie spielen auch eine wichtige Rolle bei der Diagnose von Laryngozelen, der Abklaerung von N.-laryngeus-recurrens-Paresen und Larynxfrakturen. (orig.)

  2. Functional magnetic resonance imaging in neuroradiology; Funktionelle Magnetresonanztomographie in der Neuroradiologie

    Energy Technology Data Exchange (ETDEWEB)

    Essig, M.; Schoenberg, S.O.; Schlemmer, H.P.; Metzner, R.; Kaick, G. van [Deutsches Krebsforschungszentrum, Heidelberg (Germany). Forschungsschwerpunkt Radiologische Diagnostik und Therapie

    2000-10-01

    Bildgebungssequenzen, optimierter Kontrastmittelapplikationen und spezieller Nachverarbeitungsmethoden wurde es moeglich, physiologische und pathophysiologische Prozesse mittels der Magnetresonanztomographie (MRT) zu beobachten. Mit T1- und T2*-gewichteten kontrastmittelunterstuetzten Bildgebungssequenzen koennen Informationen ueber die Gewebeperfusion, Mikrozirkulation und die Permeabilitaet der Blut-Hirn-Schranke unter Anwendung spezieller, z.T. aus der Nuklearmedizin stammender Modelle erfasst werden. Die Eigendiffusion von Wassermolekuelen im Gewebe ist mit diffusiongewichteter MRT, die Markrovaskulatur, zeitlich aufgeloest, mit MR-angiographischen Techniken darstellbar. Auch eine neuronale Aktivitaet einfacher oder komplexer Natur kann mit funktionellen MR-Techniken visualisiert werden. Mit MR-spektroskopischen Untersuchungen koennen metabolische Verteilungen in normalem und pathologischem Gewebe mehrdimensional erfasst und Stoffwechselvorgaenge im Verlauf beobachtet werden. Vorteile der MRT ist die geringe Invasivitaet, die Moeglichkeit einer dreidimensionalen Darstellung der Daten und eine beliebige Wiederholbarkeit der Untersuchung bei fehlender Strahlenbelastung. Die bereits klinisch einsetzbaren funktionellen Methoden werden beschrieben und ihr Einsatz in der Neuroradiologie auch in Bezug auf die Wertigkeit im Vergleich zu nuklearmedizinischen Methoden diskutiert. Perfusions- und Diffusions-MRT liefern wichtige Zusatzinformationen im akuten und chronischen Stadium der zerebralen Ischaemie und werden bereits routinemaessig bei akutem Schlaganfall eingesetzt. Dynamische MR-Angiographien erlauben eine haemodynamische Einstufung von Gefaessmissbildungen. In der Tumordiagnostik liefern die funktionellen MR-Techniken wichtige Zusatzinformationen fuer die Therapiefindung, Therapieplanung und das Therapiemonitoring. Die Untersuchung psychiatrischen Erkrankungen wurden durch die funktionelle MRT revolutioniert, obwohl der klinische Einsatz noch limitiert ist. Erste Untersuchungen

  3. Coxarthrosis; Koxarthrose

    Energy Technology Data Exchange (ETDEWEB)

    Imhof, H.; Czerny, C.; Gahleitner, A.; Grampp, S.; Kainberger, F.; Krestan, C. [Osteologie, Radiodiagnostik, AKH Wien (Austria); Sulzbacher, I. [Institut fuer Klinische Pathologie, AKH Wien (Austria)

    2002-06-01

    ;'activated'' osteoarthritis under standard therapy, unclear joint-pain and before any arthroscopy. (orig.) [German] Koxarthrosen gehoeren zu den am haeufigsten auftretenden Arthrosen. Es besteht eine geringe Praevalenz des maennlichen Geschlechts. Aetiologisch werden primaere and sekundaere Koxarthrosen unterschieden. Primaere (idiopathische) sind aetiologisch unklar, sekundaere beruhen auf bekannten Aetiologien (z. B. Uebergewicht, repetitive Traumen, Fehlstellung bzw. Fehlhaltung, Muskel bzw. Sehnenimbalanz etc.). Pathophysiologisch finden sich bei Arthrosen Knorpel-, Subchondralregion-, Synovialis-, Gelenkfluessigkeitsveraenderungen sowie Abnormitaeten in den periartikulaeren Muskeln. Waehrend im Knorpel stadienhaft oedematoese Schwellung, Defekt mit Riss, Fibrillation, Glatzenbildung und Knorpelregeneratbildung sowie Gelenkspaltverschmaelerung auftreten, zeigen sich subchondral kleinste Oedembildungen, Nekrosen, evtl. Mikrofrakturen und Demineralisation sowie die bekannten subchondralen Sklerosierungen, Zystenbildungen und osteophytaeren Neubildungen. In spaeterer Folge kommt es zu Deformierungen und Fehlstellung. Letztere Veraenderungen sind mittels konventionellen Roentgenaufnahmen, CT und MRT gut abgrenzbar.Von zunehmender Bedeutung ist heute auch die Diagnostik sog. Praearthrosen. Dazu zaehlen aetiologisch u. a. unterschiedliche Fehlstellungen, Fehlformen, evtl. Labrumpathologien sowie die oben genannten Sehnen- und Muskelimbalanzen.Koxarthrosen werden in 3 prognostisch unterschiedliche Typen differenziert, abhaengig von der Migration des Kopfes: die laterokraniale als haeufigste, die mediokaudale und die seltene axiale. Ihre Entstehung duerfte auf unterschiedliche Mechanismen zurueckgehen.Die bildgebende Diagnostik erfolgt beim Vorliegen einer entsprechenden klinischen Symptomatik. Basis der Bildgebung ist heute unveraendert das konventionelle Roentgenbild, gefolgt von CT und MRT. Zur Diagnostik der ''aktivierten Arthrose'' wird nach wie vor die

  4. Imaging of bacterial infections of the sacroiliac joint; Darstellung bakterieller Infektionen im Sakroiliakalgelenk

    Energy Technology Data Exchange (ETDEWEB)

    Groves, C.; Cassar-Pullicino, V. [Radiology Department, Robert Jones and Agnes Hunt Orthopaedic Hospital Oswestry (United Kingdom)

    2004-03-01

    eindeutigen praedisponierenden Faktoren festzustellen. Die Zeitspanne zwischen dem ersten Auftreten der Symptome und der endgueltigen Diagnose ist in der Regel erheblich. Das klinische Bild ist oft unspezifisch und variabel, und die schwierige klinische Beurteilung kann darauf beruhen, dass es sich um einen relativ selten auftretenden Zustand handelt. Ausserdem ist die klinische Untersuchung der Sakroiliakalgelenke sehr problematisch. Die Diagnose basiert auf Anamnese und klinischen Befunden. Sie weisen zusammen mit Blutkultur und/oder einem ev. Gelenkspunktat auf eine Infektion im Sakroiliakalgelenk hin. Das haeufigste klinische Symptom bei bakteriellen Infektionen sind Schmerzen im unteren Teil der Wirbelsaeule oder im Gesaess. Mittels einer STIR-Sequenz, welche die Sakroiliakalgelenke gut darstellt, koennen Pathologien relativ einfach und aeusserst frueh entdeckt werden. Von allen bildgebenden Verfahren ist MRT daher die Methode der Wahl bezueglich Sensitivitaet und Spezifitaet. Falls eine MRT aufgrund geringer Verfuegbarkeit nicht durchfuehrbar ist, sollte als zweite Methode der Wahl die 3-Phasenknochenszintigraphie durchgefuehrt werden. Der konventionellen Roentgendiagnostik kommt weder in der Frueh- noch Verlaufsdiagnostik eine entscheidende Rolle zu. Eine CT-gefuehrte Gelenkpunktion kann in unklaren Faellen die diagnostische Treffsicherheit erhoehen. Eine Therapiekontrolle ist am besten mittels Tc99m Blutpool-Untersuchungen moeglich. Eine hochgradige klinische Verdachtsdiagnose und eine fruehe MRT-Untersuchung sind die wesentliche Voraussetzung fuer die exakte Diagnose einer bakteriellen Sakroiliitis. (orig.)

  5. Arterial spin labelling in imaging of renal diseases and renal allograft pathology; MRT-Perfusionsmessung mit Arterial Spin Labelling. Anwendung fuer die Niere und Transplantatniere

    Energy Technology Data Exchange (ETDEWEB)

    Hueper, Katja; Gutberlet, Marcel [Medizinische Hochschule Hannover (Germany). Inst. fuer Diagnostische und Interventionelle Radiologie; Kuehn, Bernd [Siemens AG/Siemens Healthcare GmbH, Erlangen (Germany)

    2016-06-15

    Arterial Spin Labelling (ASL) is a technique for non-invasive and contrast-free assessment of perfusion with MRI. Renal ASL allows examination of renal pathophysiology, evaluation of the course of renal disease and therapy effects by longitudinal measurements as well as characterization of renal tumors. In this article, techniques of ASL will be explained and challenges of renal ASL will be emphasized. In addition, examples for clinical application of ASL for diagnosis of renal disease and renal allograft pathology will be given.

  6. Morphometric analysis of the temporomandibular joint with MRI in 320 joints; Morphometrische Analyse des Kiefergelenkes anhand von 320 Gelenken mit der MRT

    Energy Technology Data Exchange (ETDEWEB)

    Lemke, A.J.; Felix, R. [Charite, Univ. Berlin, Campus Virchow-Klinikum, Klinik fuer Strahlenheilkunde (Germany); Griethe, M.; Peroz, I.; Lange, K.P. [Charite, Univ. Berlin, Campus Virchow-Klinikum, Zentrum fuer Zahnmedizin, Abt. fuer zahnaerztliche Prothetik und Alterszahnmedizin (Germany)

    2005-02-01

    Purpose: to compare several morphometric parameters in MRI with the functional status of the articular disc in a large patient group suffering from internal derangement (ID) of the temporomandibular joint (TMJ). Materials and methods: in a retrospective study, 320 analyzable high resolution MRI examinations of the TMJs obtained in a 1.5 T unit were evalu