Science.gov (United States)

This laboratory exercise demonstrates some basic principles in parasitology by using experimental studies of the relationship of Hymenolepis diminuta with its rodent host.

Energy Technology Data Exchange (ETDEWEB)

In 15 patients (16 hip joints) we found the clinical and radiological signs of BMOS. On T1-weighted MRI images areas of low signal intensity could be observed in the head, neck and the intertrochanteric region of the femur in various extensions. These areas showed a significant increase in signal intensity on the T2-weighted images. Because pain was resistant to conservative therapy all these patients were treated by core decompression of the femoral head in a prospective study. Bone cores were evaluated histologically using undecalcified sections and quantitative microradiography. The existence of intramedullary oedema in exactly the regions exhibiting the MRI pattern of bone marrow oedema was verified histologically; however, bone and marrow changes similar to those of early avascular necrosis (AVN) were also visible. (orig.)

UK PubMed Central (United Kingdom)

In this study, bone mineral density (BMD) of normal (CON), ovariectomized (OVX) and partially nephrectomized (NFR) rats was measured by ³¹P NMR spectroscopy; bone matrix density was...Full Text Available

British Library Electronic Table of Contents (United Kingdom)

Porous flow occurs in a wide range of materials and applies to many commercially relevant applications such as oil recovery, chemical reactors and contaminant transport in soils. Typically, breakthrough and pressure curves of column floods are used in the laboratory characterization of these materials. These characterization methods lack the detail to easily and unambiguously resolve flow mechanisms with similar effects at the core scale that can dominate at the aquifer or oil field scale, as well as the effects of geometry that control the flow at interfaces as in a perforated well or the inlet of an improperly designed column. Non-invasive imaging techniques such as MRI have been shown to provide a far more detailed characterization of the properties of the solid matrix and flow, but usu...

Energy Technology Data Exchange (ETDEWEB)

This paper advances hypotheses on the chemistry of the interaction of thorium and yttrium with organic-inorganic salts of molybdenum polyacids. On the basis of an analysis of the data of an adsorption experiment and the quantitative relationships that follow from the law of mass action, it is shown that thorium is absorbed by the solid phase by coprecipitation with the participation of complex formation, while the coprecipitation of yttrium with salts of polyacids is due to a reaction of ion exchange chemisorption.

CERN Document Server

The Principles of Radioactive Waste Management

KoreaScience (Korea)

Full Text Available

KoreaScience (Korea)

Full Text Available

International Nuclear Information System (INIS)

We devised a three-dimensional method for estimation of cerebral development and myelination which measures cerebral volume using MRI. Accuracy of the system was estimated using cadaver brains. The mean percentage error in the calculated volumes compared with the real volumes was 2.33 %, range 0.00-5.33 %. We applied the method to the volume of both cerebral hemispheres (CH), basal ganglia, thalamus and internal capsule (BT), and myelinated white matter (WM) in 44 neurologically normal individuals (4 months to 28 years of age), 13 patients with spastic motor disturbances (2-25 years of age), and 9 patients with athetotic motor disturbances (2-23 years of age). In the neurologically normal cases, the volumes of CH, BT and WM increased with age; the volume of MW more slowly than that of CH. In cases with spastic motor disturbances, the volumes of CH, BT and WM were between -1.4 and 3.5 SD, -1.0 and -3.5 SD, and 0.0 and -5.2 SD respectively, of those of ...

International Nuclear Information System (INIS)

Early white matter (WM) injury affects brain maturation in preterm infants as revealed by diffusion tensor imaging and volumetric magnetic resonance (MR) imaging at term postmenstrual age (PMA). The aim of the study was to assess quantitatively brain maturation in preterm infants with and without milder forms of WM damage (punctate WM lesions, PWML) using conventional MRI. Brain development was quantitatively assessed using a previously validated scoring system (total maturation score, TMS) which utilizes four parameters (progressive myelination and cortical infolding, progressive involution of glial cell migration bands and germinal matrix tissue). PWML were defined as foci of increased signal on T1-weighted images and decreased signal on T2-weighted images with no evidence of cystic degeneration. A group of 22 preterm infants with PWML at term PMA (PWML group) were compared with 22 matched controls with a normal MR ...

CERN Document Server

We demonstrate the use of a variational method to determine a quantitative lower bound on the rate of convergence of Markov Chain Monte Carlo (MCMC) algorithms as a function of the target density and proposal density. The bound relies on approximating the second largest eigenvalue in the spectrum of the MCMC operator using a variational principle and the approach is applicable to problems with continuous state spaces. We apply the method to one dimensional examples with Gaussian and quartic target densities, and we contrast the performance of the basic Metropolis-Hastings algorithms with a ``smart'' variant that incorporates gradient information into the trial moves. We find that the variational method agrees quite closely with numerical simulations. We also see that the smart MCMC algorithm often fails to converge geometrically in the tails of the target density except in the simplest case we examine, and even then care must be taken to choose ...

Energy Technology Data Exchange (ETDEWEB)

A first-principles quasiparticle approach to the electronic excitation energies in crystals and at surfaces is described. The quasiparticle energies are calculated within the GW approximation for comparison with photoemission and other spectroscopic experiments. Applications of the method to bulk semiconductors and the Si(111)2[times]l, Ge(111)2[times]l. and H/Si(III) surfaces are presented. In both cases, significant self-energy corrections arising from many-electron effects to the excitation energies are found. Using atomic positions from total energy minimization, the calculated excitation energies explain quantitatively the experimental spectra. This approach thus provides an ab initio means for analyzing and predicting results from spectroscopic probes.

International Nuclear Information System (INIS)

We investigated the isotropic diffusion coefficient (D') and fractional anisotropy (FA) in white matter (WM) during brain development, using an optimised diffusion-tensor imaging (DTI) method with whole brain coverage in a clinically acceptable time. We images 52 children with no evident neurological abnormality (30 boys, 22 girls aged 1 day-16 years) using high-angle DTI with optimised temporal gradient performance. D' and FA were calculated in 10 regions of interest in white matter. We saw that the age-related reduction in D' and increase in FA follow a mono- or biexponential model in white matter, probably depending on the compactness and myelination rate of the fibre tracts. In contrast to other areas, in which adult values were reached during the third year, there is a trend to continuous increase in FA in all deep white-matter areas, suggesting continuing maturation and organisation of deep tracts not detected on conventional MRI. (orig.)

Energy Technology Data Exchange (ETDEWEB)

Magnetic resonance imaging (MRI) as a diagnostic imaging tool relies on the generation of magnetic fields, whereas the computerized tomography (CT) uses X-radiation. The fundamental principle of MRI is the magnetic resonance of paramagnetic atomic nuclei. These nuclei, as e.g. protons (= hydrogen nuclei), are aligned in required orientation by application of a strong magnetic field. Upon simultaneous application of an electromagnetic high-frequency field perpendicular to the axis of the basic magnetic field, and in response to periodical changing of the electromagnetic field at a given frequency, the originally aligned paramagnetic nuclei are forced into a movement similar to that of a ``whipping top``. When the resonance frequency is shut off, the nuclei return to their former, aligned positions, inducing a weak signal in a coil. The series of signals generated by multiple repetition of this process of excitation of nuclei ...

KoreaScience (Korea)

Full Text Available

International Nuclear Information System (INIS)

We reported three cases of acute intracranial tuberculosis including miliary tuberculosis, basal meningitis, tuberculomas and neuritis of cranial nerves. All patients had native and contrast enhanced CT and MRI scans. MRI revealed more granulomas and a better imaging contrast in the detection of basal meningitis. Neuritis was diagnosed only with the MRI. MRI scans should be prefered as the imaging procedure in clinically presumed intracranial tuberculosis. (orig.).

KoreaScience (Korea)

Full Text Available

KoreaScience (Korea)

Full Text Available

KoreaScience (Korea)

Full Text Available

KoreaScience (Korea)

Full Text Available

International Nuclear Information System (INIS)

The authors present a comparison between the diagnostic accuracy of Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) in the articular pathologies of the knee. CT and MRI were performed in 30 patients who subsequently underwent surgery. CT and MRI results were compared on three bases: technique, definition of normal anatomy, and diagnostic accuracy. CT allowed a standardization of the technique, while MRI was superior in defining normal anatomy - especially in the study of capsulo-ligamentous structures. In all cases the use of both CT and MRI allowed a correct diagnosis, showing the site, extent and gravity of the lesion. CT proved to be superior to MRI in 4 cases, while MRI corrected CT diagnosis in 11 cases; in 15 patients both techniques had the same diagnostic accuracy. Meniscal tears were better identified by CT, while ...

International Nuclear Information System (INIS)

We describe a 16-month-old boy presenting with stridor and fever. The chest X-ray suggested inhalation of a foreign body but here was no history of this. A high spot a T_1-weighted chest MRI was due to a peanut which was seen to have moved from the right main bronchus to the left inferior bronchus, between the two MRI studies. MRI can provide information on position and size of the peanut, the conditons of the surrounding tissues and may be also useful in treatment. We consider MRI to be a valuable new method for the diagnosis of peanut inhalation. (orig./GDG).

CERN Document Server

Digital Libraries

International Nuclear Information System (INIS)

Purpose: The aim of this study was to demonstrate the typical appearance of ganglioneuromas in computer-assisted tomography (CT), and magnetic resonance imaging (MRI). Material and methods: Retrospective analysis of diagnostic imaging (9 CT, 6 MRI) in 9 children aged 3 to 15 years with the histological diagnosis of ganglioneuroma. Results: The tomographies showed large (max. 13.4 cm in diameter) round or oval tumors with sharp delineation. The sites of the tumors were the retroperitoneum (5), the mediastinum (3), and the adrenal gland (1). Intraspinal tumor involvement occurred in 4 cases. On comparing CT with MRI, MRI was more accurate in defining the intraspinal involvement. The ganglioneuromas were of hypodense appearance in the native CT scan and showed moderate enhancement upon administration of contrast media. In five patients tumor calcifications with a disseminated sprinkled pattern were seen in ...

International Nuclear Information System (INIS)

Fetal MRI examines non-invasively the unborn fetus. Ultrafast MRI sequences effectively suppress fetal motion. Multiple case reports and studies have shown that fetal MRI is particularly helpful in the evaluation of the central nervous system. The high contrast-to-noise ratio, the high spatial resolution, the multiplanar capabilities, the large field of view and the simultaneous visualisation of fetal and maternal structures have proven to be advantageous. Fetal MRI is particularly helpful in the evaluation of the normal and pathological development of the brain. Despite the fact that no side effects have been reported or are to be expected, the use of MRI during pregnancy is still limited to the second and third trimester of pregnancy. Magnetic resonance imaging contrast media are not to be used as it passes the placenta. Ultrasound remains the primary screening modality for fetal ...

Science.gov (United States)

A first-principles task-based approach to the design of medical ultrasonic imaging systems for breast lesion discrimination is described. This study explores a new approximation to the ideal Bayesian observer strategy that allows for object heterogeneity. The new method, called iterative Wiener filtering, is implemented using echo data simulations and a phantom study. We studied five lesion features closely associated with visual discrimination for clinical diagnosis. A series of human observer measurements for the same image data allowed us to quantitatively compare alternative beamforming strategies through measurements of visual discrimination efficiency. Employing the Smith-Wagner model observer, we were able to breakdown efficiency estimates and identify the processing stage at which performance losses occur. The methods were implemented using a commercial scanner and a cyst phantom to explore development of spatial filters for systems ...

UK PubMed Central (United Kingdom)

The purpose of this study was to synthesize biocompatible polyvinylpyrrolidone (PVP)-coated iron oxide (PVP-IO) nanoparticles and to evaluate their efficacy as a magnetic resonance imaging (MRI)...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

A case of {beta}-thalassemia intermedia with spinal cord compression due to extramedullary hematopoiesis, which was successfully treated by blood transfusion, is presented. Emphasis was made on the MRI appearance of extramedullary hematopoiesis on different pulse sequences. The theories that aimed to explain the involvement of the epidural space by extramedullary hematopoiesis are discussed.

UK PubMed Central (United Kingdom)

In Diffusion Tensor Magnetic Resonance Image (DT-MRI) processing a 2^nd order tensor has been commonly used to approximate the diffusivity function at each lattice...Full Text Available

UK PubMed Central (United Kingdom)

A common approach used to fuse simultaneously recorded EEG and fMRI is to correlate trial-by-trial variability in the EEG, or variability of components derived therefrom, with the blood oxygenation...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

The current role of magnetic resonance imaging (MRI) in different organ systems is discussed and compared to nuclear medicine and to other available clinical diagnostic modalities. The value of optimizing radiofrequency pulse sequence selection to provide additional tissue characterization is also described. The results of nuclear medicine and MRI studies in 56 patients are compared to evaluate the clinical diagnostic contribution of each imaging modality for various pathological processes. In addition, the state-of-the-art MRI systems and future development in MRI technology with its potential contribution is defined.

International Nuclear Information System (INIS)

This book is an anatomical reference for cranial magnetic resonance imaging (MRI) studies in neonates and infants. It contains 122 clear, sharp MRI scans and drawings showing changes in the normal appearance of the brain and skull during development. Sections of the atlas depict the major processes of maturation: brain myelination, development of the corpus callosum, development of the cranial bone marrow, and iron deposition in the brain. High-quality scans illustrate how these changes appear on magnetic resonance images during various stages of development.

UK PubMed Central (United Kingdom)

BackgroundSupport vector machine (SVM) has been widely used as accurate and reliable method to decipher brain patterns from functional MRI (fMRI) data. Previous studies have not...Full Text Available

British Library Electronic Table of Contents (United Kingdom)

The combination of functional and morphological imaging technologies such as positron emission tomography (PET) and X-ray computed tomography (CT) has shown its value in the clinical and preclinical field. However, CT provides only very limited soft-tissue contrast and exposes the examined patient or laboratory animal to a high X-ray radiation dose. In comparison to CT, magnetic resonance tomography (MRI) provides excellent soft-tissue contrast and allows for nuclear magnetic resonance spectroscopy (NMRS) or functional MRI (fMRI). Thus, the combination of PET and MRI has been pursued for several years. First approaches have succeeded using conventional photo multiplier tube (PMT) technology together with light fibers to transfer scintillation light away from the high magnetic field. Latest...

International Nuclear Information System (INIS)

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 ...

International Nuclear Information System (INIS)

We evaluated in this study the value of preoperative examinations of anal atresia with an optimised MRI strategie. 13 patients with anorectal anomalies, most of them younger than one year, underwent an MRI examination of the pelvis. 10 of these patients were operated afterwards. Compared with the situs shown by the operation the results of the MRI examination were very exact in all cases in respect of the level of atresia and the development of the striateed muscle complex. Fistulas could be completely described in most cases. MRI demonstrated additional lesions in some patients which were of great importance for planning the further treatment of the patients. As a consequence MRI can give valid information on anal atresia for planning the operative treatment. (orig.).

International Nuclear Information System (INIS)

Dynamic CT and MRT were performed in 21 patients who had undergone prosthetic replacement of the aorta because of dissection of the thoracic aorta. There is no difference between MRI and dynamic CT in the demonstration of a persistent intimal flap, the formation of a thrombus and the assessment of the aortic diameter in patients who underwent surgery for thoraco-abdominal aortic dissection. MRI, however, is superior in the identification of the true and false lumen and the demonstration of the distal anastomotic site. The major advantages of MRI are that there is no need for intravenous contrast agents, that it is high sensitive to flow phenomena, and that it can demonstrate the aortic arch and the ascending aorta on sagittal oblique sections. The major disadvantages of MRI are the limited access to the patient during the procedure, and the inability to examine patients fitted with pacemakers or who are ...

International Nuclear Information System (INIS)

Authors obtained T1-weighted MRI images of the femoral head after fracture of the femoral neck and classified the signals into four patterns to investigate the sequential changes of the femoral head. The T1-weighted MRI images obtained initially after femoral neck fracture showed a normal pattern in 10 of the 15 hip joints studied. MRI images obtained subsequently still showed the normal signal pattern in eight of the 10 hip joints which had shown the normal pattern in the first MRI, while two of the 10 joints subsequently showed a band pattern. The joint with the homogeneous pattern in the first MRI subsequently showed a band pattern. Of the three joints with an inhomogeneous pattern in the first MRI, two joints showed a subsequent band pattern, and the other a normal pattern. The joints which showed a band pattern continued to show a similar band pattern. ...

International Nuclear Information System (INIS)

The combination of functional and morphological imaging technologies such as positron emission tomography (PET) and X-ray computed tomography (CT) has shown its value in the clinical and preclinical field. However, CT provides only very limited soft-tissue contrast and exposes the examined patient or laboratory animal to a high X-ray radiation dose. In comparison to CT, magnetic resonance tomography (MRI) provides excellent soft-tissue contrast and allows for nuclear magnetic resonance spectroscopy (NMRS) or functional MRI (fMRI). Thus, the combination of PET and MRI has been pursued for several years. First approaches have succeeded using conventional photo multiplier tube (PMT) technology together with light fibers to transfer scintillation light away from the high magnetic field. Latest PET/MRI developments use solid-state light detectors that can be operated even at high ...

International Nuclear Information System (INIS)

Patients with haemarthros of the knee were examined by MRI and arthroscopy to identify the bleeding source and to determine surgical or conservative therapy. A prospective study was performed on 120 patients who underwent MRI and arthroscopy, point lesions and bleeding sources were documented separately on a standardised form. Arthroscopy demonstrated a ruptured anterior cruciate ligament in 86%, meniscal tears in 55%, disruption of collateral ligaments in 17%, osteochondral lesions in 5% and tears of capsule or plicae in 13%. Disruption of cruciate ligaments caused haemorrhage in all but three cases. In contrast, only meniscal tears located very adjacent to the meniscal basement had bled. Those types of osteochondral lesions caused haemorrhage characterised on MRI by destruction of the subchondral plate and overlying cartilage. Severe lesions of the knee were diagnosed by MRI in 71% to 100%, slight ...

UK PubMed Central (United Kingdom)

ObjectiveTo describe the development and assessment of monographs as an assignment to incorporate evidence-based medicine (EBM) and pharmacoeconomic principles into a third-year...Full Text Available

International Nuclear Information System (INIS)

Differentiating a benign from a malignant lesion by information such as density data, or signal intensities or echo gradients, is not possible with CT, nor MRI, nor ultrasonography. Only some lesions show characteristic signs. Inflammations cannot be difscriminated from malignant tumors. CTs of small tumors in particular are so poor in contrast that it is much more difficult to detect tumors or discriminate them from other lesions, as compared to MR images or ultrasonographs. CT does not detect surface tumors, but is more sensitive than MRI or US in detecting discrete cortical bone lesions. The same applies to small calcified tumors. MRI however is most sensitive in detecting tumor volumes in the yellow marrow, and is the best modality for evaluation of extraossal extension of tumors. CT yields better results than MRI if applied for simultaneous screening of lymph node metastases in the lower neck. ...

International Nuclear Information System (INIS)

We compared the values of the myocardial thickness and the left ventricle diameters measured with MRI and echocardiography. The ejection fraction was compared in MRI and ventriculography. 34 patients with different heart dysfunctions were examined with MRI (FISP 2D sequence). 26 of them were also studied by echocardiography and 20 by biplane cine-ventriculography. The enddiastolic thicknesses of the left ventricular postero-lateral wall and of the septum interventriculare were measured on short axis images. An ellipsoidal modell was used for volume calculation and ejection fraction. Correlation of MRI values of thickness and ejection fraction with echocardiographi and angiographi showed r>0,8. As known for 1.56 T Imagers, the myocardial thickness in MRI was underestimated compared to echocardiography (1.4 mm#+-#1.7). The ejection fraction was underevaluated compared to ...

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

Energy Technology Data Exchange (ETDEWEB)

Nasal cavity volume was studied in 69 healthy volunteers (from 8 to 23 years old) by MRI. The right and left nasal cavity areas were measured on horizontal images displayed directly on the MRI console. The nasal cavity volume was obtained by integrated volume calculation. The nasal cavity volume was positively correlated with age, body height and weight up to age 16. The body height and weight reached a plateau at 16 years, but the nasal cavity volume continued to increase. There was no significant difference in the volumes of the right and left cavities. (author).

International Nuclear Information System (INIS)

The book is a German translation of an American textbook with the original title ''MRI Survival Guide'' and is intended to serve as an introductory guide for beginners or a reference book for quick information. Readers will find information on the fundamentals of the technology and methodology of MRI as well as all details of relevance to practice in a precise and easy-to-grasp arrangement, covering all anatomic areas of interest, illustrations and descriptions of characteristic signs of pathologic processes, high-quality and unusually large-sized diagnostic pictures, a modern didactic concept for quick orientation, including surveys, tables, and reproductions for visualisation of contents. (orig./CB)

International Nuclear Information System (INIS)

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 ...

International Nuclear Information System (INIS)

A prospective study was performed on 50 patients suffering from osteochondritis dissecans of the knee and ankle to define criteria for stability and fixation of osteochondral lesions. Morphological parameters in MRI (size, fragmentation, cartilage, interface) and conventional radiology (separation, fragmentation) were registered and compared with arthroscopical staging. MRI staging based on different types of interfaces was demonstrated on T_1- and T_2-weighted images. MRI could correctly predict a Grade 1 lesion in 50%, a Grade 2 lesion in 90%, a Grade 3 lesion on 0%, and a Grade 4 lesion in 79%. Stable lesions were differentiated from unstable lesions in 90%. Radiographic findings corresponded with arthroscopic staging in only 56% of the cases because fibrotic connection may guarantee stability in case of bony separation. (orig./MG).

International Nuclear Information System (INIS)

We report a 55-year-old woman with coccydynia due to a sacral mass. The histological diagnosis was haemangioma. The MRI findings and the unusual location of this lesion are discussed. (orig.)

International Nuclear Information System (INIS)

The MRI's of 16 patients with either primary or secondary lymphatic disorders are evluated and the findings are compared to those from lymphangioscintigraphy or surgery. (author).

International Nuclear Information System (INIS)

We present two cases of fetal neck masses that were initially diagnosed by ultrasound and further evaluated with prenatal MRI. MRI findings aided in further delineating the neck masses, increasing confidence in the final diagnosis (cervical teratoma and cystic hygroma). With the fetal airway typically filled with fluid that is of high signal on T2-weighted sequences, MRI images in three planes could identify whether the fetal larynx and trachea were partially or completely compressed by the neck tumor. This information was particularly useful in determining if a controlled delivery such as ex utero intrapartum treatment (EXIT) was necessary and aided the surgeons in planning their approach to establishing airway control in the delivery room. (orig.)

UK PubMed Central (United Kingdom)

Cerebral periventricular white matter injury stands as a leading cause of cognitive, behavioral and motor impairment in preterm infants. There is epidemiological and histopathological evidence...Full Text Available

British Library Electronic Table of Contents (United Kingdom)

Abstract During the past few years, laparoscopy has become the gold standard for some surgical procedures and its applications continue to expand. Because of multiple factors such as loss of tactile perception, two-dimensional visualization of the three-dimensional surgical field, and demanding bimanual hand-eye coordination, special training is required to achieve proficiency with laparoscopy. In this study, as the first step toward evidence-based development of strategies to improve the quality of laparoscopy training from brain activity and behavior relationships, a laparoscopy training simulator was developed for use in functional MRI. Experiments confirmed the functional MRI compatibility of the device. Representative behavioral and functional MRI results for two subjects showed the f...

Energy Technology Data Exchange (ETDEWEB)

In France, groundwater usage represents 40 per cent of volumetric use, outside of thermal power plants. Groundwater represents 60 per cent of domestic and public use, 40 per cent in the industrial sector, and is increasing in the agricultural sector where it accounts for 20 per cent. Groundwater withdrawal in France has slightly increased over the last twenty years and benefited the agricultural sector. Availability throughout the territory, the consistency of resupply and natural quality has rendered groundwater a prevailing source for drinking water. Water protection and management is important and led to the adoption of legislative and regulatory measures. The Mining Code (Code minier) allows for exploitation of underground resources starting at 10 metres. The Rural Code (Code rural) mandates the declaration of public utility for water collection for the public. Protection areas are to be provided under the Public Health Code (Code de sante publique). Proper permits and ...

UK PubMed Central (United Kingdom)

The evaluation of biological markers is recognized as necessary to the future of toxicology, epidemiology, and quantitative risk assessment. For biological markers to become widely accepted, their validity...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

Positron emission tomography (PET) and magnetic resonance imaging (MRI) studies were performed on a case of neuro-Behcet's syndrome. In accordance with the clinical signs, FDG PET (using /sup 18/F-labeled 2-F-2'-desoxyglucose) revealed disseminated storage defects in the cerebrum and cerebellum. Focal regions of enhanced signal intensity were demonstrated in the parietal white matter of the cerebrum in T2-weighted images and in the brain stem by MRI. (orig.).

UK PubMed Central (United Kingdom)

To assess which specific morphologic features, enhancement patterns, or pharmacokinetic parameters on breast Magnetic Resonance Imaging (MRI) could predict a false-negative outcome of Proton...Full Text Available

International Nuclear Information System (INIS)

Intervertebral spacers for anterior spine fusion are made of different materials, such as titanium and cobalt chromium alloys and carbon fiber-reinforced polymers. Implant-related susceptibility artifacts can decrease the quality of MRI scans. The aim of this cadaveric study was to demonstrate the extent that implant-related MRI artifacting affects the postfusion differentiation of determined regions of interest (ROIs). In six cadaveric porcine spines, we evaluated the postimplantation MRI scans of a titanium, cobalt-chromium and carbon spacer that differed in shape and surface qualities. A spacer made of human cortical bone was used as a control. A defined evaluation unit was divided into ROIs to characterize the spinal canal as well as the intervertebral disc space. Considering 15 different MRI sequences read independently by an interobserver-validated team of specialists the artifact-affected image ...

International Nuclear Information System (INIS)

The aim of this study was to evaluate typical magnetic resonance imaging (MRI) findings in early rheumatic diseases manifesting at the soft tissues of the hand using a retrospective analysis. A total of 186 MRI examinations of patients with clinical suspicion of a rheumatic disease were evaluated in a consensus reading by two experienced radiologists. All imaging patterns were assessed with respect to their type and localization. Under blinded and non-blinded conditions diagnoses were correlated with final clinical diagnosis. The most frequent diagnoses were rheumatoid arthritis (RA, 45.7%) and psoriatic arthritis (PsA, 15.6%). The mean correlation between clinical and MRI diagnosis (r) was 0.75 in blinded and 0.853 in non-blinded reading (p <0.001). The following extra-articular imaging patterns were found: synovitis (59.1%), tendovaginitis (91.4%), dactylitis (14.5%), and bone marrow edema (18.3%). Only dactylitis was ...

International Nuclear Information System (INIS)

Sonography, subtraction scintigraphy, computed tomography and MRI were compared in 100 patients who had surgery 105 times for hyperparathyroidism (HPT). Surgical and pathological data were available for all operations. A total of 105 MR, 77 CT, 84 sonograms and 70 subtraction scintigrams were performed. The ability of the imaging modalities, individually and in combination, to detect HPT, histology, size, concomitant thyroid disease and location of the diseased glands has been evaluated. For primary HPT, sensitivity ranged from 68% for MRI to 40% for scintigraphy but was much lower for tertiary HPT with all modalities. The ability to identify diseased glands was strongly size dependent for all methods. If patients had had previous neck surgery, the most sensitive methods were MRI and scintigraphy and this also held true for patients with concomitant thyroid disease and ectopically located glands. The findings presented ...

International Nuclear Information System (INIS)

The primary aim was to evaluate delayed contrast-enhanced MRI in depicting perineural spread of hilar cholangiocarcinoma (CCC) and consequently to determine the capability of MRI/MRCP for staging CCC. Fifteen patients that underwent MRI/MRCP and surgical treatment were retrospectively included. Two radiologists evaluated MR images to assess delayed periductal enhancement, extent of bile duct stenosis, liver parenchymal and vascular involvement and presence of liver atrophy. An agreement between delayed enhancement of the bile duct walls and perineural neoplastic spread showed a very good correlation factor (0.93). The overall accuracy in detecting biliary neoplastic invasion was higher for delayed T1-weighted images (93.3%) than for the MRCP images (80%), and T1-delayed image increased the MR accuracy in assessing the neoplastic resectability (p < 0.05). MRI correctly predicted vascular involvement ...

International Nuclear Information System (INIS)

To compare the accuracy in the detection and staging of various malignant tumors with high resolution whole-body MRI using parallel imaging with whole-body dual-modality PET-CT. Preliminary results of an interim analysis from a prospective, blinded study are presented, in which 20 patients (mean age 59 years, range 27-77 years) with different oncological diseases underwent whole-body dual modality FDG-PET-CT screening for tumor search or staging in case of confirmed or suspected metastatic disease. All patients also underwent whole-body MRI imaging with the use of parallel imaging (iPAT). High-resolution coronal T1w- and STIR-sequences of 5 body levels with 512 x 512 matrix, axial fast T2w imaging of lung and abdomen (HASTE), contrast-enhanced dynamic and static T1w-sequences of liver, brain, abdomen, and pelvis were performed. Using a 32-channel whole-body MRI scanner (Magnetom Avanto, Siemens Medical Solutions) with a ...

Science.gov (United States)

No Abstract Available

International Nuclear Information System (INIS)

Published in summary form only.

KoreaScience (Korea)

Full Text Available

Energy Technology Data Exchange (ETDEWEB)

This contribution is intended to introduce the principles of quantum computing to those who always wanted to know about quantum computing but never dared to ask. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

UK PubMed Central (United Kingdom)

Abstract This paper focuses on the basic principles of information technology (IT) organization within health sciences centers. The paper considers the placement of the leader of the...Full Text Available

Science.gov (United States)

... Missionaries and Cannibals, etc.) Since the shooting example is intended to be an example of general autonomous reasoning, we will avoid such ...

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

International Nuclear Information System (INIS)

The purpose of this study is to develop a geometrically accurate imaging protocol at 3 T magnetic resonance imaging (MRI) for stereotactic radiosurgery (SRS) treatment planning. In order to achieve this purpose, a methodology is developed to investigate the geometric accuracy and stability of 3 T MRI for SRS in phantom and patient evaluations. Forty patients were enrolled on a prospective clinical trial. After frame placement prior to SRS, each patient underwent 3 T MRI after 1.5 T MRI and CT. MR imaging protocols included a T1-weighted gradient echo sequence and a T2-weighted spin echo sequence. Phantom imaging was performed on 3 T prior to patient imaging using the same set-up and imaging protocols. Geometric accuracy in patients and phantoms yielded comparable results for external fiducial reference deviations and internal landmarks between 3 T and 1.5 T MRI (mean ?0.6 mm; ...

International Nuclear Information System (INIS)

In this review, we demonstrate the developmental appearance, structural features, and reorganization of transient cerebral zones and structures in the human fetal brain using a correlative histological and MRI analysis. The analysis of postmortem aldehyde-fixed specimens (age range: 10 postovulatory weeks to term) revealed that, at 10 postovulatory weeks, the cerebral wall already has a trilaminar appearance and consists of: (1) a ventricular zone of high cell-packing density; (2) an intermediate zone; (3) the cortical plate (in a stage of primary consolidation) with high MRI signal intensity. The anlage of the hippocampus is present as a prominent bulging in the thin limbic telencephalon. The early fetal telencephalon impar also contains the first commissural fibers and fornix bundles in the septal area. The ganglionic eminence is clearly visible as an expanded continuation of the proliferative ventricular zone. The basal ganglia showed an ...

Energy Technology Data Exchange (ETDEWEB)

Results of discrete element method (DEM) simulation and magnetic resonance imaging (MRI) experiments are compared for monodisperse granular materials flowing in a half-filled horizontal rotating cylinder. Because opacity is not a problem for MRI, a long cylinder with an aspect ratio {approximately}7 was used and the flow in a thin transverse slice near the center was studied. The particles were mustard seeds and the ratio of cylinder diameter to particle diameter was approximately 50. The parameters compared were dynamic angle of repose, velocity field in a plane perpendicular to the cylinder axis, and velocity fluctuations at rotation rates up to 30 rpm. The agreement between DEM and MRI was good when the friction coefficient and nonsphericity were adjusted in the simulation for the best fit. {copyright} {ital 1998 American Institute of Physics.}

Energy Technology Data Exchange (ETDEWEB)

We report the delayed sequelae arising in a case of electrical injury, reviewing the literature on the subject and focusing on the MRI findings of the brain. A 23-year-old male suffered burns to the left parietal scalp, both feet, and the anterior chest wall. Neurological symptoms and MRI abnormalities appeared 14 days after the insult and continued for about three months. T1-weight MR images demonstrated homogeneous hypointensity, while T2-weighted images depicted hyperintense finger-like projections. Contrast-enhanced T1-weighted images demonstrated strong band-like enhancement, indicating meningeal hyperemia. Follow-up MR imaging showed that the lesion had disappeared, indicating that the cerebral edema and meaningeal hyperemia were reversible.

International Nuclear Information System (INIS)

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.)

Energy Technology Data Exchange (ETDEWEB)

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.)

International Nuclear Information System (INIS)

One of the central issues in radiation protection consists in determining what weight should be given to individual doses in relation to collective or aggregated doses. A mathematical framework is introduced in which such assessments can be made precisely in terms of comparisons between alternative distributions of individual doses. In addition to evaluation principles that are well known from radiation protection, a series of principles that are derived from parallel discussions in moral philosophy and welfare economics is investigated. A battery of formal properties is then used to investigate the evaluative principles. The results indicate that one of the new principles, bilinear prioritarianism, may be preferable to current practices, since it satisfies efficiency-related properties better without sacrificing other desirable properties.

Energy Technology Data Exchange (ETDEWEB)

Heat transfer processes use fluids which are generally not pure and can react with transfer surfaces. These surfaces are subject to deposits which can be sediments harmful to heat transfer and to integrity of materials. For nuclear plant steam generators, sludge build-up accelerates secondary side corrosion by concentrating chemical species. A major safety problem involved with such a corrosion is the growing of circumferential cracks which are very difficult to detect and size with eddy current probes. With a view to understand and control this problem, it is necessary to develop a mathematical model for the prediction of sludge behavior in PWR steam generators. Based on fundamental principles, this work intends to use different models available in literature for the prediction of the phenomenon leading to the accumulation of sludge particles at the bottom (the tubesheet) of a PWR. For that, a three-dimensional simulation of magnetite particulate fouling with the ...

UK PubMed Central (United Kingdom)

The noninvasive assessment of cardiac function is of first importance for the diagnosis of cardiovascular diseases. Among all medical scanners only a few enables radiologists to evaluate the local cardiac...Full Text Available

International Nuclear Information System (INIS)

Diffusion magnetic resonance imaging (MRI) has become an important tool in the radiologic diagnosis of diseases of the brain as it measures molecular motion of water that characterizes the microstructure of tissues. Its most important clinical use to date is the early detection of cerebral ischemia by revealing the ischemic injury shortly after vessel occlusion and simultaneously providing therapy-relevant information on the tissue at risk. Furthermore, diffusion MRI is diagnostically promising in other diseases of the brain and is thus increasingly becoming part of routine clinical protocols in the diagnosis of tumors, inflammation, trauma, demyelination, dysmyelination and neurodegeneration. Although abnormalities of diffusion are generally not pathognomonic, diffusion MRI affords information about tissue changes for specific disorders that complements information obtained with standard MR techniques and frequently shows ...

DEFF Research Database (Denmark)

The sources of non-white noise in Blood Oxygenation Level Dependent (BOLD) functional magnetic resonance imaging (fMRI) are many. Familiar sources include low-frequency drift due to hardware imperfections, oscillatory noise due to respiration and cardiac pulsation and residual movement artefacts not accounted for by rigid body registration. These contributions give rise to temporal autocorrelation in the residuals of the fMRI signal and invalidate the statistical analysis as the errors are no longer independent. The low-frequency drift is often removed by high-pass filtering, and other effects are typically modelled as an autoregressive (AR) process. In this paper, we propose an alternative approach: Nuisance Variable Regression (NVR). By inclusion of confounding effects in a general linear model (GLM), we first confirm that the spatial distribution of the various fMRI noise sources is similar to what has already been ...

UK PubMed Central (United Kingdom)

A technique is described for displaying distinct tissue layers of large blood vessel walls as well as measuring their mechanical strain. The technique is based on deuterium double-quantum-filtered (DQF)...Full Text Available

UK PubMed Central (United Kingdom)

Background and purposeRadial head fractures are common, and may be associated with other injuries of clinical importance. We present the results of a standard additional MRI scan...Full Text Available

UK PubMed Central (United Kingdom)

Posterior spinal ligament pathology is becoming increasingly recognized as a significant cause of low back pain. Despite the growing clinical importance of interspinous ligament degeneration in low...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

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. ...

Energy Technology Data Exchange (ETDEWEB)

The study was designed to determine the correlation between parenchymal lesions on MRI and depression. Thirty patients with depression satisfying the following criteria were selected: (1) 60 years or over at the time of MRI scanning, (2) no evidence of cerebrovascular disorder or dementia, and (3) no evidence of neurological findings such as extremity palsy. Seventy six patients with no history of psychiatric visits to a clinic served as controls. There was no significant difference in risk factors for cerebrovascular disorders, such as hypertension, diabetes mellitus, and ischemic heart disease, between the depressive group and the control group. MRI manifestations were semiquantitatively scored according to the periventricular hyperintensity (PVH), white matter hyperintensity (WMH), and pons hyperintensity (PH). All of the PVH score, WMH score, and cerebral enlargement index correlated with age. Although there was no ...

UK PubMed Central (United Kingdom)

ObjectiveTo investigate the impact white matter hyperintensities (WMH) detected on MRI have on motor dysfunction and cognitive impairment in non-demented elderly...Full Text Available

International Nuclear Information System (INIS)

Three dimensional data of brain from the formalin-fixed fetuses were collected without isolation, by the 4.7 tesla super high magnetic field MRI and the developmental process of the cerebral parenchyma was studied by 3D images. Subjects were 13 fetal brain and MRI was performed using 3D-steady-state free precession sequence. The isolated brain is very soft and fragile and is deformed by its weight at the imaging. However 3D-MRI can be obtained without isolation, and the deformation is remarkably small. The subependymal germinal matrix layer did not be observed in 7 weeks-old fetus, appeared at 9 weeks-old and increased gradually. Then it rapidly reduced from 28 weeks-old. The volume calculated, from 3D-MRI, increased rapidly from 9 weeks-old to 23 weeks-old, and reached the maximum (2.346 mm"3) at 23 weeks-old. The relation between fetal ages and volume of cerebral ventricle also showed similar pattern. ...

UK PubMed Central (United Kingdom)

Background:There is a need for simple imaging parameters capable of predicting therapeutic outcome.Methods:This retrospective study analysed 50 patients...Full Text Available

UK PubMed Central (United Kingdom)

Convection-enhanced drug delivery (CED) is a novel approach to delivering drugs into brain tissue. Drugs are delivered continuously via a catheter, enabling large volume distributions of high drug concentrations...Full Text Available

UK PubMed Central (United Kingdom)

The common factor that underlies several types of functional brain imaging is the electric current of masses of dendrites. The prodigious demands for the energy that is required to drive the...Full Text Available

Medline Plus

... catheter ablation for paroxysmal atrial fibrillation procedure utilizing 3-D mapping and rotational intracardiac echocardiography. This program is ... of the MRI scan and then there's the 3-D image, which is generated from the pixels chosen ...

International Nuclear Information System (INIS)

The comprehensive survey explains the indications and the specific value of the modern tomographic modalities with respect to the various diagnostic issues. Numerous reproductions of CT, MRI, US scans illustrate the aspects discussed. (orig./CB)

UK PubMed Central (United Kingdom)

Effective connectivity in brain networks can be studied using Granger causality analysis which is based on temporal precedence, while functional connectivity is usually derived using zero-lag...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

Intracapsular femoral neck fractures remain unsolved fractures even after improvement in techniques of diagnosis and internal fixation. Individuals who sustain displaced femoral neck fractures are at high risk of developing avascular necrosis and non-union. Although several methods for predicting the viability of femoral head have been reported, they are not effective or widely used because of unreliability, potential complications and technical difficulties. Dynamic MRI was introduced in the recent past as a simple, non-invasive technique to predict the femoral head viability after the femoral neck fractures. In this study role of dynamic MRI was studied in 30 patients with 31 intracapsular femoral neck fractures. Fractures were divided in to three types according to dynamic curve patterns on MRI evaluation and were followed up for 6 months to 2 years to observe the final outcome. Sensitivity, Specificity and the Accuracy ...

Energy Technology Data Exchange (ETDEWEB)

Objective: To compare the histopathology of nodular fasciitis (NF) with the magnetic resonance imaging (MRI) findings in order to evaluate the basis of the MR signal characteristics. Design and patients: Ten patients with NF, nine females and 1 male, with an age ranging from 13 to 58 years (mean 26.8 years) were studied. MRI findings, available in all 10 patients, were compared with the histopathology in nine patients, and an area-to-area comparative study of the whole specimen section histopathology and MRI was performed in two patients. Results: On the basis of an excisional biopsy or resection specimen, the nine lesions were classified into myxoid (n=4), cellular (n=3) and fibrous (n=2) subtypes. Four myxoid lesions with a subcutaneous location showed a homogeneous SI comparable with muscle on T1-weighted images, high SI on T2-weighted images, and had homogeneous enhancement. One cellular lesion presented with ...

International Nuclear Information System (INIS)

A 37-year-old military mechanic presented to our institution with a chronic history of a slowly enlarging left elbow antecubital fossa mass. There was no history of other chronic illness or trauma. Magnetic resonance imaging (MRI) and excisional biopsy revealed fatty villi and synovial inflammation within the left bicipitoradial bursa, consistent with lipoma arborescens. Four years later the patient presented with a 6-month history of swelling at the antecubital fossa of the opposite elbow. Diagnostic computed tomography and MRI examinations were performed. The surgical and pathologic findings confirmed the imaging diagnosis of lipoma arborescens at the right bicipitoradial bursa. (orig.)

International Nuclear Information System (INIS)

Purpose: For planning the therapeutic strategies and estimating the prognosis in esophageal cancer, N-staging is very important. To date, MRI still is of minor importance as imaging modality of the mediastinum despite promising developments in the past, like ECG-gating or 'averaging' sequences, e.g. LOTA (Long-term averaging), which facilitate mediastinal and thoracic MR-imaging. In a prospective approach, the value of MRI based N-staging was examined with respect to LOTA-sequences. Material and Methods: Within from weeks prior to esophagectomy, standardized MRI of the esophagus was performed in 15 patients (10 squamous-cell-carcinomas and 5 adenocarcinomas) using a 1.5 T whole body scanner. Imaging quality was classified based on depiction of aortic wall or tracheal wall layers. Criteria for malignant infiltration were a diameter of more than 15 mm or a round appearance of a lymph node together with GD-DTPA enhancement. ...

Energy Technology Data Exchange (ETDEWEB)

Objective: To assess dynamic MRI with Gd-DTPA enhancement for evaluating inflammatory changes in the subacromial bursa. Design and patients: We detected the signal intensity changes in dynamic MRI of the subacromial bursa, and confirmed these macroscopically by arthroscopy and histologically. The signal intensity was measured using built-in software, and the enhancement ratio (E ratio) was calculated from dynamic MR images. In addition, as a parameter of the rate of the increase in the signal intensity from 0 to 80 s, the mean increase per second in the E ratio was obtained as the coefficient of enhancement (CE). The correlation was studied of the E ratio and CE with the arthroscopic findings (redness, villous formation, thickening and adhesion), and of the E ratio and CE with the histological findings (capillary proliferation, papillary hyperplasia, fibrosis and inflammatory cell infiltration) of the subacromial bursa. Of patients with ...

Energy Technology Data Exchange (ETDEWEB)

January, 1992, to October, 1995, sixty-four patients with advanced head and neck cancer underwent head and neck reconstructive surgery using myocutaneous or revascularized flaps; in the same period, all patients were consecutively examined with CT and MRI. Myocutaneous flaps were used in 26 patients: 12 flaps were tubular and 14 linear. Revascularized flaps were used in 38 patients: to repair a large defect in 26 patients (14 latissimus dorsi flaps and 12 temporal muscle flaps) and to repair an oral damage in 12 patients (5 revascularized radial and 7 jejunal flaps). CT and MR images of myocutaneous flaps showed the flaps as fatty areas, repairing large surgical defects, hypodense at CT and hyperintense at MRI, with no post-contrast enhancement. The appearance of revascularized flaps at CT and MRI depends on the characteristics of the structure used to repair the surgical defect: jejunal and radial flaps appeared as mostly ...

UK PubMed Central (United Kingdom)

OBJECTIVETo assess the new quantitative bone scan parameters as markers of Charcot neuroosteoarthropathy (CNO) activity.RESEARCH DESIGN AND METHODSForty-two...Full Text Available

UK PubMed Central (United Kingdom)

Effective small interfering RNA (siRNA)–mediated therapeutics require the siRNA to be delivered into the cellular RNA-induced silencing complex (RISC). Quantitative information of this essential...Full Text Available

UK PubMed Central (United Kingdom)

We have exploited ``progeny testing'' to map quantitative trait loci (QTL) underlying the genetic variation of milk production in a selected dairy cattle population. A total of 1,518 sires, with progeny...Full Text Available

UK PubMed Central (United Kingdom)

Deficits in prepulse inhibition (PPI) are a biological marker for schizophrenia. To unravel the mechanisms that control PPI, we performed quantitative trait loci (QTL) analysis on 1,010 F2 mice derived...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

Purpose: Measurement of the oscillating CSF flow in the spinal canal (SC) of healthy volunteers and in patients with post-traumatic syringomyelia (PTS) using an optimized MRI protocol as well as to determine whether stenosis induced velocity changes are detectable using MRI. Methods: In 68 healthy volunteers quantitative studies of CSF flow in the cervical, thoracic, and lumbar regions were performed. First, an optimized sequence was developed and tested in 19 volunteers using four different flow-encoding velocities (4, 8, 12, 16 cm/s). Secondly, the optimized sequence was employed in 49 volunteers to measure the different CSF patterns in the cervical, thoracic, and lumbar spinal canals (CSC, TSC, LSC). Part three of the study, in which patients with PTS are being examined is still underway. We measured the maximum velocity (cm/s), the pixel area (mm{sup 2}), and the stroke volume (ml/s). Using a flow model the velocities ...

International Nuclear Information System (INIS)

1986. p. 390-392. Germany Brecht-Krauss, D. Kusmierek, J. Adam, WE Ulm

KoreaScience (Korea)

Full Text Available

International Nuclear Information System (INIS)

Published in summary form only.

Energy Technology Data Exchange (ETDEWEB)

We investigated the efficacy of combined FDG-PET/CT imaging for the diagnosis of small-size uveal melanomas and the feasibility of combining separate, high-resolution (HR) FDG-PET with MRI for its improved localization and detection. Patients, methods: 3 patients with small-size uveal melanomas (0.2-1.5 ml) were imaged on a combined whole-body PET/CT, a HR brain-PET, and a 1.5 T MRI. Static, contrast-enhanced FDG-PET/CT imaging was performed of head and torso with CT contrast enhancement. HR PET imaging was performed in dynamic mode 0-180 min post-injection of FDG. MRI imaging was performed using a high-resolution small-loop-coil placed over the eye in question with T2-3D-TSE and T1-3D-SE with 18 ml Gd-contrast. Patients had their eyes shaded during the scans. Lesion visibility on high-resolution FDGPET images was graded for confidence: 1: none, 2: suggestive, 3: clear. Mean tumour activity was calculated for summed image ...

DEFF Research Database (Denmark)

Methods for estimating particle number may be based on at least three different principles. Two of them, isolation of particles and indirect counting, have been predominant until recently. The new methods based on section pairs (disectors) are unbiased and far more efficient. The three principles and their historical developments are described, emphasizing that the newly developed principles have old roots, which were forgotten until recently. It is concluded, that 'learned societies' combined with individual enthusiasm are material for the spread and development of new ideas.

Science.gov (United States)

... Each beam finite element was derived using Hamilton's principle and the following basic assumptions: the beam has an arbitrary amount of pretwist ...

Energy Technology Data Exchange (ETDEWEB)

The report gives general principles of treatment and care of casualties caused by radiation accidents or nuclear explosions.

Energy Technology Data Exchange (ETDEWEB)

The operating principle is examined for an optical sensor for the angle of rotation of the drag ODUP-1 developed and manufactured by the VNII-1. Basic technical data are presented for the experimental model.

Science.gov (United States)

The principles of radionuclide excitation of X-ray fluorescence radiation and its application in

Science.gov (United States)

... d Diameter of ro.'ling element of a cylindrical roller bearing ... L Life (B-10) of a cyl.ndrical roller bearing LACA Contact ratio ...

Energy Technology Data Exchange (ETDEWEB)

A summary of the basic principles of K-matrix theory and examples of its applications to atomic spectra are discussed. (AIP)

International Nuclear Information System (INIS)

... feasibility studies fftf reactor loss of flow reactor control systems reactor core

Energy Technology Data Exchange (ETDEWEB)

Early recognition of recurrence and work-up of clinically indeterminate lesions may be impaired after reconstruction with silicone implants due to superimposition of the implant or to scarring. This study was undertaken to evaluate the use of contrast-enhanced MRI in patients with silicone implant after breast cancer. Contrast-enhanded MRI was offered to 169 patients. Comparative two- to three-view mammography was also performed in 169 patients, as well as comparative sonography in 144 patients. Conventional imaging and clinical examination detected only 8/13 recurrences, whereas 12/13 were detected by MRI. One recurrence had been visible as a strongly enhancing 2-mm dot in a previous examination (2 years before), but was not called. It was therefore counted as false negative. In addition, multicentricity was detected by MRI alone in two of three cases. MRI correctly diagnosed scar ...

Energy Technology Data Exchange (ETDEWEB)

Purpose: To determine the value of MRI in the preoperative evaluation of chronic paranasal sinusitis and to compare the results with CT and intraoperative findings. Method/Materials: 42 patients with clinical signs of chronic paranasal sinusitis underwent MRI after CT evaluation on one day, with subsequent functional endoscopic sinus surgery on the next day. Coronary CT was obtained with 5-mm slices and table-feed in the prone position, while MRI was performed in the supine position with coronary T{sub 2}-TSE+pd and coronary and transverse HASTE, each with 5-mm slice thickness. Aquisition time in MRI was less than 8 minutes. Two radiologists reviewed the CT and MRI scans for signs of sinusitis and detection of anatomical landmarks. The results were correlated with the intraoperative findings. Results: MRI offered no artifacts of dental work and showed more often ...

Energy Technology Data Exchange (ETDEWEB)

CT and MRI of acquired abnormalities of the inner ear and cerebello-pontine angle present themselves with very typical findings. The imaging should be adapted to the pathology looked for and either CT or MRI should be used alone or in combination.CT, especially high resolution CT (HRCT), provides an excellent bone contrast, while MRI has a much superior soft tissue contrast. Acute inflammatory changes of the inner ear are solely depicted by contrast-enhanced MRI. HRCT excellently depicts osseous changes of the inner ear and cerebellopontine angle such as chronic ossifying labyrinthitis occurring after acute labyrinthitis, otosclerotic or traumatic changes. Tumorous changes not yielding to bony changes are best delineated by MRI. Posttraumatic hemorrhage and chronic fibrotic changes within the labyrinth are depicted by MRI, only. In conclusion HRCT and ...

International Nuclear Information System (INIS)

Eleven patients who had undergone cardiac surgery were studied by means of high-field MR imaging (1.5 T). Six patients had aortic root and valve replaced with a Bjork-Shiley (BS) composite tubular aortic graft prosthesis for acute dissection of ascending aorta. In the other 5 patients with rheumatic calcific aortic disease, the valve had been replaced with a BS prosthesis. As a whole, MR studies were 14. Previous evaluations of magnetic field effects had seem carried out ex vivo on both BS valves and BS composite prostheses, on surgical ligation clips (Tantalium and Stainless) and on stainless wires for sternal closure. In 4 patients (2 BS composite grafts, and 2 BS valves) MRI diagnosed chronic dissection of both arch and descending aorta. In 1 of them, with a bs valve, associated localized acute dissection of ascending aorta was observed. In 3 patients with BS composite grafts, MRI revealed pseudo-aneurysms (including a thrombosed one) at the ...

Energy Technology Data Exchange (ETDEWEB)

(1) To determine the accuracy of computed tomography (CT) in the evaluation of ligament tear and avulsion in patients with tibial plateau fracture. (2) To evaluate whether the presence or severity of fracture gap and articular depression can predict meniscal injury. A fellowship-trained musculoskeletal radiologist retrospectively reviewed knee CT and MRI examinations of 41 consecutive patients presenting to a level 1 trauma center with tibial plateau fractures. Fracture gap, articular depression, ligament tear and footprint avulsions were assessed on CT examinations. The MRI studies were examined for osseous and soft tissue injuries, including meniscal tear, meniscal displacement, ligament tear, and ligament avulsion. CT demonstrated torn ligaments with 80% sensitivity and 98% specificity. Only 2% of ligaments deemed intact on careful CT evaluation had partial or complete tears on MRI. Although the degree of fracture gap ...

British Library Electronic Table of Contents (United Kingdom)

AbstractPurpose: To implement and examine the feasibility of a three-dimensional (3D) ultrashort TE (UTE) sequence on a 7 Tesla (T) clinical MR scanner in comparison with 3T MRI at high isotropic resolution. Materials and Methods: Using an in-house built saddle coil at both field strengths we have imaged mid-diaphysial sections of five fresh cadaveric specimens of the distal tibia. An additional in vivo scan was performed at 7 Tesla using a quadrature knee coil. Results: Using the same type of saddle coil at both field strengths, a significant increase in SNR at 7T compared with 3T (factor 1.7) was found. Significantly shorter T2* values were found at the higher field strength (T2* = 552.2 126 s at 7T versus T2* = 1163 391 s at 3T). Conclusion: UHF MRI at 7T has great potential for imaging...

International Nuclear Information System (INIS)

Superparamagnetic MFe23+O4 (M=Mn2+, Fe2+ and Co2+) inverse spinel ferrite (ISF) nanoparticles with narrow size distribution having average diameters of 6-8 nm were synthesized by a diol reduction of organic metals and the surface was modified to be hydrophilic by coating with succimer. Magnetic resonance imaging (MRI) contrast enhancement by dipolar coupling defined interactions between the synthesized ISFs and protons in the bulk water was investigated with initial susceptibility, magnetization and anisotropy of the succimer-coated ISFs. The relaxivity ratios, r2/r1, for MnFe2O4, Fe3O4 and CoFe2O4 were measured to be 12.2, 23.1 and 62.3, respectively, which demonstrate the potential usefulness of these magnetic nanoparticles as T2 contrast agents for MRI.

Energy Technology Data Exchange (ETDEWEB)

The MRI morphology in combined subacute degeneration has only rarely been reported. We describe two patients suffering from subacute combined degeneration of the spinal cord on the basis of a deficiency of vitamin B{sub 12}. In both patients characteristic hyperintense areas on T{sub 2}-weighted images in the posterior columns of the cervical and thoracic cord without contrast enhancement were demonstrated by MRI. (orig.) [Deutsch] Bisher liegen zur wenige Beschreibungen der MR-Morphologie bei funikulaerer Myelose vor. Wir beschreiben zwei Patienten mit den klinischen Zeichen einer funikulaeren Myelose auf der Basis eines Vitamin B{sub 12}-Mangels. Bei beiden konnten mit der MRT charakteristische Signalanhebungen im T{sub 2}-gewichteten Bild in den Hinterstraengen des zervikalen und thorakalen Rueckenmarks gezeigt werden. Eine Kontrastmittelaufnahme war nicht nachweisbar. (orig.)

International Nuclear Information System (INIS)

Purpose: With intracranial tumors a flat, contrast-enhancing, probably dural structure adjacent to the tumor can occasionally be observed on gadolinium-DTPA enhanced MR images. Therefore we have attempted to evaluate a tumor infiltration of this enthancement on MRI. Material and Methods: This study included 50 patients. 19 patients had a dural thickening at the tumor base (13 meningiomas and 6 metastases), while 31 patients did not (12 meningiomas and 19 metastases). Studies included plane T_2-weighted spin echo (SE) images as well as T_1-weighted axial, coronal, or sagittal plains with and without contrast agent. Histopathological examinations, were done on the tumor base adjacent to the dura mater. Results: 7 of 12 meningiomas showed a meningeal thickening on MRI with histopathologically proven tumor infiltration as did also 5 of 6 metastases. But 3 of 12 meningiomas and 15 of 19 metastases without dural thickening at the tumor base also ...

International Nuclear Information System (INIS)

The essential properties of tachyons are described briefly and the 'reinterpretation principle' for tachyons is discussed. The possibility of conducting an experiment analogous to the Michelson-Morley experiment in which a preferred frame may be detected is considered. The existance of a tachyon prefered frame is consistent with the principles of relativity and, if suitable experiments were devised, could provide important evidence for the existence of tachyons. (W.D.L.).

International Nuclear Information System (INIS)

It is confirmed that actuality of tachyons and some unusual properties may be due to inadequate mathematical formalism based on the Lorentz group. Insertion of tachyons requires in addition to generalization of the causality principle also an extension of the relativistic invariance principle. It is proposed a way in the paper which removes a number of problematic situations in the tachyon problem.

Energy Technology Data Exchange (ETDEWEB)

This paper is a tutorial discussion of the basic principles of ground relaying for high voltage and extra high voltage transmission lines. Three different HV configurations are considered: Long lines, lines with a weak mid-point station, and mutually-coupled lines. Application criteria for EHV circuits are also discussed, and specific setting calculations are included where appropriate.

Energy Technology Data Exchange (ETDEWEB)

Primary malignant lymphoma of the brain is a disease of unknown etiology, which is increasing in incidence and has an unfavorable prognosis. Despite the lack of specific changes on CT or MRI in most cases, these procedures may typically facilitate the diagnosis: A focal-enhancing mass with subependymal spread on CT or MRI and hyperattenuation on nonenhanced CT are the most reliable features in the diagnosis of primary malignant lymphoma of the brain. Peritumoral edema and mass effect are usually not prominent features. On unenhanced CT scans they usually appear homogeneously isodense to mildly hyperdense relative to the gray matter. On MRI these tumors are slightly hypointense on T1-weighted images and slightly hpyerintense on PD- and T2-weighted images relative to the gray matter. On CT and MRI enhancement is usually homogeneous. Contrast-enhanced MRI, with its multiplanar ...

British Library Electronic Table of Contents (United Kingdom)

The main goal of local drug delivery is to increase the concentration of a specific therapeutic agent in a target tissue with minimal nontarget distribution. Compared to systemic therapy, local drug delivery provides a high level of therapeutic efficacy with minimal systemic effects. The current primary imaging modality for drug delivery has been x-ray angiography, but it has major limitations including anatomical ambiguity and inability to visualize the targeted tissues. Due to these inherent problems, MR guidance has been explored as an alternative imaging modality for guiding and monitoring of drug therapy. Recently, interventional MR (XMR) systems have been implemented that have both dual x-ray and MRI capabilities in a single suite and allow for real-time interventional procedures to ...

International Nuclear Information System (INIS)

This paper reports that only a few years ago superconducting magnetic separation was viewed as the next major market for superconducting magnets. The first commercial units had been installed, worked flawlessly, and demonstrated real economic viability. The potential market was seen as quite large, and many people believed that superconducting magnetic separation would soon show the same rapid growth that MRI had demonstrated after its initial success. These hopes even prompted IGC, one of the top MRI magnet builders, to form a separate division devoted to magnetic separation. Despite the existence of Magstream, IGC has not been overly active in the market. As a technology that has applications from the clay on the Earth to the soil on the moon, superconducting magnetic separation has yet to become widely used.

International Nuclear Information System (INIS)

Herein we present an impact of diagnosis by enhanced multidetector-row computed tomography and magnetic resonance imaging for extrahepatic cholangiocarcinoma (ECC). Although the diagnosis against the longitudinal stromal extension and surrounding tissue invasion of ECC by multi detector row CT (MDCT) and MRI was very strict, we could not detect any superficial mucosal spread (SMS). Furthermore, the diagnosis of lymphnode metastasis by MDCT/MRI was miserable. We believe that misdiagnosis of SMS is permissible since positive mucosal but not stromal surgical margin was not a significant factor influencing the postoperative prognosis. However, further advances in imaging diagnosis for ECC is needed. (author)

British Library Electronic Table of Contents (United Kingdom)

The objective of this study was to develop full body CAD geometry of a seated 50th percentile male. Model development was based on medical image data acquired for this study, in conjunction with extensive data from the open literature. An individual (height, 174.9?cm, weight, 78.6???0.77?kg, and age 26?years) was enrolled in the study for a period of 4?months. 72 scans across three imaging modalities (CT, MRI, and upright MRI) were collected. The whole-body dataset contains 15,622 images. Over 300 individual components representing human anatomy were generated through segmentation. While the enrolled individual served as a template, segmented data were verified against, or augmented with, data from over 75 literature sources on the average morphology of the human body. Non-Uniform Rational...

International Nuclear Information System (INIS)

AFFF has fabricated the (U, Pu)O_2 mixed oxide fuels for PHWRs, BWRs, PFBRs and FBTRs. The quantitative dissolution of the fuel samples are required within time for accurate determination of uranium-plutonium in chemical quality control laboratory. This paper describes the use of microwave heating technique in quantitative dissolution of (U, Pu)O_2 MOX (from 0.4% to 44% PuO_2). (author)

UK PubMed Central (United Kingdom)

BackgroundDiscrepancies between the conclusions of different meta-analyses (quantitative syntheses of systematic reviews) are often ascribed to methodological differences. The objective...Full Text Available

UK PubMed Central (United Kingdom)

Motivation: Automatic recognition of cell identities is critical for quantitative measurement, targeting and manipulation of cells of model animals at single-cell resolution. It has been...Full Text Available

UK PubMed Central (United Kingdom)

BACKGROUND: An approach to the study of the pharmacokinetics of drugs in the lung is to measure their concentrations in bronchial biopsy specimens. The main criticism of this technique is that bronchial...Full Text Available

UK PubMed Central (United Kingdom)

Absolute measurements of cerebral blood flow (CBF) are an important endpoint in studies of cerebral pathophysiology. Currently no accepted method exists for in vivo longitudinal...Full Text Available

UK PubMed Central (United Kingdom)

OBJECTIVEEvaluate the qualitative and quantitative differences between moderated and unmoderated on-line social support groups focused on asthma.DESIGNA...Full Text Available

International Nuclear Information System (INIS)

1984. p. 680-685. Germany Glaubitt, D. Siafarikas, K. Staedtische

UK PubMed Central (United Kingdom)

BackgroundSeveral fractal and non-fractal parameters have been considered for the quantitative assessment of the vascular architecture, using a variety of test specimens and of computational...Full Text Available

UK PubMed Central (United Kingdom)

OBJECTIVE AND DESIGNThis study used qualitative and quantitative methods to examine the reasons primary care physicians and nurses offered for their inability to initiate guideline-concordant...Full Text Available

UK PubMed Central (United Kingdom)

In this model, without dark matter, the flat rotation curves of galaxies and the mass-to-light ratios of clusters of galaxies are described quantitatively. The hypothesis is that the agent of gravitational...Full Text Available

UK PubMed Central (United Kingdom)

Gadolinium (Gd) based contrast agents (GBCAs) in magnetic resonance imaging (MRI) are used in daily clinical practice and appear safe in most patients; however, nephrogenic systemic fibrosis...Full Text Available

International Nuclear Information System (INIS)

A solid pseudopapillary tumor is an uncommon tumor of the pancreas that rarely metastasizes to other organs and usually shows good prognosis. An extrapancreatic tumor arising from a solid pseudopapillary tumor is very rare. We report a case of an atypical extrapancreatic solid pseudopapillary tumor that arose from the great omentum and disseminated to the peritoneum, and discuss the radiologic findings, including the CT, US, and MRI

Energy Technology Data Exchange (ETDEWEB)

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 evaluated in 184 patients with clinically suspected ID. The analysis included the anatomical structures and a number of morphometric parameters previously described in the literature. The parameters were compared with the position of the articular disc. Results: the disc position was categorized as ''normal'' (NDP, 21.9%, n = 70), ''anterior displacement with reduction on opening'' (AMR, 51.6%, n = 165) and ''anterior displacement without reduction on opening'' (AOR, 26.6%, n = 85). With ...

Energy Technology Data Exchange (ETDEWEB)

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 MR-pathological correlation of inflammatory and neoplastic pancreatic changes, including pancreatitis, adenocarcinoma, acinar cell carcinoma, rare cystic and solid pancreatic neoplasms, and islet cell tumors. By highlighting the correlation of key pathological features with MR findings, a better understanding of the MR appearance of pancreatic pathology can be provided. In addition, MRI may prove a powerful tool in detection and characterization of pancreatic tumors. (orig.) [Deutsch] Das MR-tomographische Erscheinungsbild von Pankreatitiden und Adenokarzinomen des Pankreas, als den haeufigsten Pankreaserkrankungen, ist zwar ausreichend ...

UK PubMed Central (United Kingdom)

Amyloid plaques are a characteristic feature in Alzheimer’s disease (AD). A novel non-toxic contrast agent is presented, Gd-DTPA-K6Aβ1–30, which is homologous to Aβ,...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

Patients with haemarthros of the knee were examined by MRI and arthroscopy to identify the bleeding source and to determine surgical or conservative therapy. A prospective study was performed on 120 patients who underwent MRI and arthroscopy, point lesions and bleeding sources were documented separately on a standardised form. Arthroscopy demonstrated a ruptured anterior cruciate ligament in 86%, meniscal tears in 55%, disruption of collateral ligaments in 17%, osteochondral lesions in 5% and tears of capsule or plicae in 13%. Disruption of cruciate ligaments caused haemorrhage in all but three cases. In contrast, only meniscal tears located very adjacent to the meniscal basement had bled. Those types of osteochondral lesions caused haemorrhage characterised on MRI by destruction of the subchondral plate and overlying cartilage. Severe lesions of the knee were diagnosed by MRI in 71% to 100%, slight ...

Energy Technology Data Exchange (ETDEWEB)

Functional imaging of the pharynx used to be the domain of cineradiography, CT and ultrafast CT. The development of modern MRI techniques led to new access to functional disorders of the pharynx. The aim of this study was to implement a new MRI technique to examine oropharyngeal obstructive mechanisms in patients with obstructive sleep apnea (OSA). Sixteen patients suffering from OSA and 6 healthy volunteers were examined on a 1.5 T whole-body imager (`Vision`, Siemens, Erlangen Medical Engineering, Germany) using a circular polarized head coil. Imaging was performed with 2D flash sequences in midsagittal and axial planes. Patients and volunteers were asked to breathe normally through the nose and to simulate snoring and the Mueller maneuver during magnetic resonance imaging (MRI). Prior to MRI, all patients underwent an ear, nose and throat (ENT) examination, functional fiberoptic nasopharyngoscopy and ...

Energy Technology Data Exchange (ETDEWEB)

A detailed comparison of the softness of gold and silver has been reported in the light of hard soft acid base (HSAB) principle. Gold and silver nanoparticles in organic media (i.e., organosol) have been exploited individually to establish the principle. Sulfur and nitrogen were employed as soft and borderline donating atoms to examine the metal-ligand interactions. In this regard, thiols and amines have been considered as interacting ligands with sulfur and nitrogen donor atoms respectively. The stronger affinity of gold towards softer sulfur donor as compared to nitrogen and conversely a reasonable interaction of silver nanoparticles with both the atoms authenticate the softer nature of gold nanoparticle as compared to silver one.

Energy Technology Data Exchange (ETDEWEB)

This contribution provides an overview and imparts basic knowledge on pertinent technical developments in magnetic resonance imaging (MRI) of the liver: 3D sequences, respiratory triggering, parallel imaging, and 3 Tesla (3T). 3D sequences can be used as T1-weighted (T1w) sequences for analyzing dynamics of contrast enhancement or as T2w sequences for MR cholangiography. Consistent improvements in respiratory triggering make it possible to obtain good image quality on T2w scans even in patients unable to hold their breath. Parallel imaging as a universal technique to accelerate image acquisition is particularly appropriate for MRI of the liver, and it has been shown that the reduced acquisition time is not achieved at the expense of image quality. Further progress in MRI of the liver can be expected with use of the 3T systems, but hitherto irrelevant problems must still be solved. Overall the innovations presented here, ...

Energy Technology Data Exchange (ETDEWEB)

60 patients between 17 and 72 years of age were investigated. First, an enteroclysis was performed in typical manner. The applicated methylcellulosis was blended with positive oral MR contrast media (Magnevist oral, Schering). After enteroclysis, MRI of the abdomen was performed using T1- and T2-weighted breathhold sequences (Flash 2D pre- and postcontrast and TSE) in axial and coronal planes. The length of the affected bowel and the stenosis seen with enteroclysis correlated well with the visible thickening of the small bowel wall and the stenosis seen in MRI. Using MRI, additional findings could be obtained in 28 patients, such as fistulas, abscesses or a hydronephrosis, or a better assessment of the stenosis was possible with MRI, because of the avoidance of overshadowing of the affected bowel loop with MRI. A brilliant MR-tomographic imaging of the small bowel is possible under ...

Energy Technology Data Exchange (ETDEWEB)

Parallel imaging and echo sharing techniques have markedly reduced the acquisition times for MRI of large volumes. Dynamic 2 and 3-dimensional data sets of the chest with high temporal resolution (up to 10 images/s with single slice and 2 volume/s) allow an analysis of respiratory motion of the lungs and tumors. Time-resolved 2D series in preselected planes can be used to observe respiratory motion during free breathing or after respiratory commands, e.g. to exclude chest wall invasion by a tumor or for diagnosing impairment of respiratory mechanics. Time-resolved 3D-series (4D-MRI) allow monitoring of the spatial displacement of the lungs and tumors as a whole volume. Present limitations such as an overestimation of tumor size and an underestimation of displacement due to a limited temporal resolution are expected to be overcome with further technical developments. However, 4D-MRI already appears to be the appropriate tool ...

Energy Technology Data Exchange (ETDEWEB)

A method for the quantitative determination of atmospheric hydroperoxyl radical comprising: (a) contacting a liquid phase atmospheric sample with a chemiluminescent compound which luminesces on contact with hydroperoxyl radical; (b) determining luminescence intensity from the liquid phase atmospheric sample; and (c) comparing said luminescence intensity from the liquid phase atmospheric sample to a standard luminescence intensity for hydroperoxyl radical. An apparatus for automating the method is also included.

Energy Technology Data Exchange (ETDEWEB)

A quantitative description is proposed for the depletion-induced slip thickness and velocity profile of a polymer solution near the wall-fluid interface in simple shear flow. The inhomogeneous polymer density profile at a flat wall is inserted into the equations of motion for the flow of a polymer solution near the flat wall. The theory is in quantitative agreement with simulation results. (letter to the editor)

UK PubMed Central (United Kingdom)

An (Awassi × Merino) × Merino backcross family of 172 ewes was used to map quantitative trait loci (QTL) for different milk production traits on a framework map of 200 loci across all...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

The overall objective of this project is to produce antibodies to unique modified DNA bases and develop immunochemical assays to quantitate these lesions in damaged DNA. During this past year we have developed an antibody and chemical test to quantitate a basic sites in DNA and produced antibodies to the 8-oxopurines. This report discusses the detection of a basic sites in DNA and the preparation of antibodies to 8-hydroxyadenine and 8-hydroxyguanine.

UK PubMed Central (United Kingdom)

A public health emergency such as an influenza pandemic will lead to shortages of mechanical ventilators, critical care beds, and other potentially life saving treatments. This will raise difficult...Full Text Available

UK PubMed Central (United Kingdom)

Systems biology is a rapidly expanding field that integrates diverse areas of science such as physics, engineering, computer science, mathematics, and biology toward the goal of elucidating the underlying...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

Lithium isotope separation by displacement chromatography is studied using fundamental principles; the equations are derived assuming theoretical stages in lithium adsorption bands. The concentration profiles in the band are calculated numerically under unsteady state.

International Nuclear Information System (INIS)

The problem on the ratio between the instability of physical systems and tachyons is discussed. It is shown that the tachyons participation in the real physical process of the system rearranging does not contradict any principles. It is noted that the tachyons constitute the most significant element of the systems, identifying the instability relative to the phase transition into the stable state.

Energy Technology Data Exchange (ETDEWEB)

A novel soft commutated direct current (DC) motor is introduced. The current of the commutated coil is intentionally drained before the brush disconnects the coil. This prevents the spark generation that normally occurs in conventional DC motors. A similar principle can be applied for DC generators.

International Nuclear Information System (INIS)

In this paper it is shown that the ''third postulate'' of special relativity (i.e. the so-called ''Reinterpretation principle'' by Stueckelberg and by Faynmam) is enough to implement the law of retarded casuality for tachyons even in macro-physics, when usual macro-objects interact with micro-tachyons and macro-tachyons.

International Nuclear Information System (INIS)

The present status of theoretical description of deep-inelastic lepton-nucleon as well as large angle Bhabha scattering with account for radiative corrections in the leading and next-to-leading approximations are reviewed. Also considered is a build-up principle and physical programme of the photon-photon colliders

Energy Technology Data Exchange (ETDEWEB)

The following subjects are dealt with: physics of indoor air flow, flow in individual rooms, exchange of air and pollution between individual building zones and with the outside world, thermal coupling with the building shell, thermal comfort and air quality, evaluation of the ventilation. figs., tabs., refs.

International Nuclear Information System (INIS)

Specificity of the pulses mean frequency measurement (the pulses being generated in a stochastic process) is described. Status of the domain of analog frequency meters is presented. Methods of increasing accuracy of such meters are discussed. (author).

UK PubMed Central (United Kingdom)

This report reviews neurotoxicological principles relevant to situations of hazardous waste disposal. Some of the diagnostic techniques currently used for field assessment of nervous system dysfunction...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

A considerable amount of chemical knowledge of marine sediments has been acquired in recent years but has not yet been utilized by paleomagnetists. On the other hand, geochemists are often unaware of the usefulness of numerous magnetic techniques. In this review we try to bridge this gap, and in particular, we outline many of the chemical and magnetic principles that should allow paleomagnetists to better identify and undertand chemical changes that affect the magnetic properties of marine sediments. The chemical principles include those for distinguishing the four major sources of sediments (continental, biological, authigenic/hydrogenous, volcanic/hydrothermal) from one another by determining elemental abundance distributions, as well as for investigating the stabilities of mineral phases relative to changes in pE and pH. The magnetic principles include the effects of authigenesis and diagenesis on magnetic properties, ...

Wastenet

The principle of need selecting the game of Chicken ... The Chicken (e.g.Rasmusen, 1994) tells the story of two car drivers ...6 Therefore the Chicken is also characterised as a dilemma of common aversion (Rapoport &

Energy Technology Data Exchange (ETDEWEB)

A prototype detector based on the inclined absorber layer principle is introduced. For the Liquids Reflectometer at the Spallation Neutron Source, it is shown to be a significant improvement over its current detector, which imposes an instantaneous count rate limitation of 50 kcps.

International Nuclear Information System (INIS)

The author demonstrates through a specific example that it is possible to extract rotational energy from a Kerr source (in principle, of arbitrary size but not turned black) through a reversible process by suitably injecting tachyons. (Auth.).

UK PubMed Central (United Kingdom)

A century ago, Cajal noted striking similarities between the neural circuits that underlie vision in vertebrates and flies. Over the past few decades, structural and functional studies have...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

In this college-level introductory text the authors outline the fundamental principles of meteorology. The text is divided into three sections: meteorology, regionalization of climate, and climate change. Numerous charts, graphs, and photographs are displayed with each subject. A glossary of terms is also provided at the end of the book.

UK PubMed Central (United Kingdom)

The binding interactions of four ligands differing in acid-base properties with human serum albumin (HSA) were examined as a function of temperature. Binding to HSA decreased with increasing temperature...Full Text Available

UK PubMed Central (United Kingdom)

To maximize energy efficiency, gas turbine engines used in airplanes and for power generation operate at very high temperatures, even above the melting point of the metal alloys from which they are...Full Text Available

Science.gov (United States)

A combined ozone and aerosol LIDAR was developed at the Institute of Physics of the Atmosphere at the DLR in Oberpfaffenhofen. It is an airborne version, that, based on the DIAL-principle, permits the recording of two-dimensional ozone profiles. This presentation will focus on the ozone-part; the aerosol subsection will be treated later.

Energy Technology Data Exchange (ETDEWEB)

The national standards and state derivatives must be reinforced by models of curricular reform. In this paper, ARISE presents one model based on a set of principles--coherence, integration of the sciences, movement from concrete ideas to abstract ones, inquiry, connection and application, sequencing that is responsive to how people learn.

International Nuclear Information System (INIS)

The need for noninvasive sensitive techniques for the diagnosis and follow-up of metabolic bone disease in dialysis patients has stimulated the author's interest in the efficacy of more detailed quantitative bone scintigraphy. Using hemodialysis to reduce elevated soft-tissue activity at scintigraphy, an attempt was made to assess the diagnostic sensitivity of quantitative bone scintigraphy as compared to qualitative bone scintigraphic, biochemical, radiographic and bone histologic studies. The second aim of these studies was to determine if one of the two major components of renal osteodystrophy is a major determinant for skeletal radiotracer uptake. The clinical observations on the efficacy and possible specificity of quantitative bone scintigraphy in the diagnosis and follow-up during treatment of renal osteodystrophy are presented briefly in this chapter. Thus, the use of scintigraphy for the routine detection and ...

Energy Technology Data Exchange (ETDEWEB)

We review the development and application of kinetic Monte Carlo simulations to investigate defect and dopant diffusion in ion implanted silicon. In these type of Monte Carlo models, defects and dopants are treated at the atomic scale, and move according to reaction rates given as input principles. These input parameters can be obtained from first principles calculations and/or empirical molecular dynamics simulations, or can be extracted from fits to experimental data. Time and length scales differing several orders of magnitude can be followed with this method, allowing for direct comparison with experiments. The different approaches are explained and some results presented.

CERN Document Server

We take the point of view of a particle performing random walk with bounded jumps on Z^d in a stationary and ergodic random environment. We prove the quenched large deviation principle (LDP) for the pair empirical measure of the environment Markov chain. By the contraction principle, we deduce the quenched LDP for the mean velocity of the particle and obtain a variational formula for the corresponding rate function. We propose an Ansatz for the minimizer of this formula. We verify this Ansatz for nearest-neighbor walks on Z. As a separate result, we give a probabilistic formula for the ergodic invariant density of the environment Markov chain in the case of ballistic random walk with bounded jumps on Z.

Energy Technology Data Exchange (ETDEWEB)

A variational principle is proposed for defining that canonical transformation, continuously connected with the identity transformation, which minimizes the residual, coordinate-dependent part of the new Hamiltonian. The principle is based on minimization of the mean-square generalized force. The transformation reduces to the action-angle transformation in that part of the phase space of an integrable system where the orbit topology is that of the unperturbed system, or on primary KAM surfaces. General arguments in favor of this definition are given, based on Galilean invariance, decay of the Fourier spectrum, and its ability to include external fields or inhomogeneous systems. The optimal oscillation-center transformation for the physical pendulum, or particle in a sinusoidal potential, is constructed.

Energy Technology Data Exchange (ETDEWEB)

The combination of wood gasification and high temperature fuel cells like solid oxide fuel cells (SOFC) is an interesting approach to achieve high electrical efficiencies (40%) in small scale combined heat and power plants. This combination is called 'Biomass - Integrated Gasification Fuel Cell System' (B-IGFC). The main challenge is the adjustment of the three main components gasification, gas cleaning and fuel cell. In this technology, the first proof of principle by combining a gasifier with a SOFC in a laboratory scale for more than 100 hours was achieved. During this period, no deactivation of the system was found. (author)

Energy Technology Data Exchange (ETDEWEB)

Purpose: To report the detection of con-compacted ventricular myocardium (NVCM) with MRI compared to echocardiography in 8 patients. Material and methods: Non-compaction of the ventricular myocardium is a congenital disorder characterized by an altered structure of the myocardial wall resulting from an intrauterine arrest in endomyocardial embryogenesis. The morphological findings consist of a prominent meshwork of multiple myocardial trabeculations and deep intertrabecular recesses, communicating with the left ventricular cavity. 8 consecutive patients (mean age 7.3 years) with clinical and echocardiographic signs of NCVM were examined by MRI (1.5 T, Vision, Siemens) in short axis and 2- and 4-chamber views, using T{sub 1}-weighted TSE and Cine-GRE in 6 patients and true FISP sequences in 2 patients. MRI and echocardiography were evaluated for visibility, signs of NCVM and involvement of myocardial wall segments. Thickness ...

Energy Technology Data Exchange (ETDEWEB)

Differentiating a benign from a malignant lesion by information such as density data, or signal intensities or echo gradients, is not possible with CT, nor MRI, nor ultrasonography. Only some lesions show characteristic signs. Inflammations cannot be difscriminated from malignant tumors. CTs of small tumors in particular are so poor in contrast that it is much more difficult to detect tumors or discriminate them from other lesions, as compared to MR images or ultrasonographs. CT does not detect surface tumors, but is more sensitive than MRI or US in detecting discrete cortical bone lesions. The same applies to small calcified tumors. MRI however is most sensitive in detecting tumor volumes in the yellow marrow, and is the best modality for evaluation of extraossal extension of tumors. CT yields better results than MRI if applied for simultaneous screening of lymph node metastases in the lower neck. ...

International Nuclear Information System (INIS)

Understanding human brain function, brain development and brain dysfunction is one of the great challenges of the twenty first century. Biomedical imaging has now run up against a number of technical constraints that are exposing limits to its potential. In order to overcome the current limits to high-field magnetic resonance cerebral imaging (MRI) and unleash its fullest potential, the Cea has built NeuroSpin, an ultra-high-field neuroimaging facility at its Saclay centre (in the Essonne). NeuroSpin already boasts three fully operational MRI systems. The first is a 3-tesla high-field system and the second is a very-high-field 7-tesla system, both of which are dedicated to clinical studies and investigations in humans, while the third is an ultra-high-field 17.65-tesla system designed for studies on small animals. In 2011, NeuroSpin will be commissioning an 11.7-tesla ultra-high-field system of unprecedented power that is designed for research ...

Energy Technology Data Exchange (ETDEWEB)

Nuclear medicine and magnetic resonance imaging (MRI) are widely used in cardiac diagnostics. Both techniques have been carefully evaluated and are equivalent for the assessment of regional and global wall motion as well as the evaluation of ejection fraction and cardiac volumes, though MRI is herein currently seen as gold standard. For evaluation of myocardial perfusion, extensive data exist for nuclear imaging, that, next to high diagnostic accuracy for evaluation of coronary artery disease, show incremental prognostic information and allow for independent risk stratification. Because of rapid technical advance, myocardial perfusion imaging has also become feasible with cardiac MRI. Results of recent studies are promising, but the data are few compared to perfusion scintigraphy. For viability assessment in patients with ischemic cardiomyopathy, positron emission tomography (PET) with FDG is currently seen as gold ...

Energy Technology Data Exchange (ETDEWEB)

MRI, ultrasonography and angiography were performed on 24 cases with small renal cell carcinoma, and data were compared with pathological architecture type. An average diameter of cancer was 20.8 mm (10-30 mm). Each tumor was pathologically classified into four architecture types: alveolar type (15 cases), papillary type (5 cases), tubular type (3 cases) and cystic type (1 case). In comparison with renal cortex alveolar type renal cell carcinoma showed equal or low signal in T1-weighted images and equal or high signal in T2-weighted images. Papillary and tubular types showed high signal in T1-weighted images, and low signal in T2-weighted images. In alveolar type, many cases showed equal echo in ultrasonography and hypervascularity in angiography, and in papillary and tubular types, many cases showed high echo and hypovascularity. There were many cases with papillary type small cell carcinoma which showed low signal intensity of T2-weighted images. This results ...

Energy Technology Data Exchange (ETDEWEB)

Central nervous system (CNS) manifestations in acquired immunodeficiency syndrome (AIDS) patients are an early and common feature. The spectrum of AIDS-related CNS diseases are encephalitis caused by the human immunodeficiency virus(HIV) itself, opportunistic infection, infarct and malignancy. We experienced two cases of CNS involvement in AIDS and they were serologically diagnosed as HIV encephalitis and CNS toxoplasmosis, respectively. In the case of the HIV encephalitis patient, brain MRI showed a non-enhancing lesion with high signal intensity on T2WI and low signal on T1WI and there was no mass effect on the right frontal lobe, periventricular white matter, splenium of the corpus callosum or bilateral basal ganglia. In the other case of CNS toxoplasmosis, MR showed multiple nodular and rim enhanced mass lesions in the right basal ganglia, thalamus and periventricular white matter, which were of low signal intensity on T1WI and of high intensity on T2WI. We ...

International Nuclear Information System (INIS)

The authors describe the application of an approximate fuzzy C-means (AFCM) clustering algorithm as a data dimension reduction approach to medical magnetic resonance images (MRI). Image data consisted of one T1-weighted, two T2-weighted, and one T2*-weighted (magnetic susceptibility) image for each cranial study and a matrix of 10 images generated from 10 combinations of TE and TR for each body lymphoma study. All images were obtained with a 1.5 Tesla imaging system (GE Signa). Analyses were performed on over 100 MR image sets with a variety of pathologies. The cluster analysis was operated in an unsupervised mode and computational overhead was minimized by utilizing a table look-up approach without adversely affecting accuracy. Image data were first segmented into 2 coarse clusters, each of which was then subdivided into 16 fine clusters. The final tissue classifications were presented as color-coded anatomically-mapped images and as two and three dimensional ...