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Sample records for resonance angiography db-wbmra

  1. Whole-body MR angiography with body coil acquisition at 3 T in patients with peripheral arterial disease using the contrast agent gadofosveset trisodium

    DEFF Research Database (Denmark)

    Nielsen, Yousef W; Eiberg, Jonas P; Løgager, Vibeke B

    2009-01-01

    Whole-body magnetic resonance angiography (WB-MRA) at 3 T with body coil acquisition has not previously been investigated. In this study, WB-MRA was performed in this manner using the blood pool contrast agent gadofosveset trisodium.......Whole-body magnetic resonance angiography (WB-MRA) at 3 T with body coil acquisition has not previously been investigated. In this study, WB-MRA was performed in this manner using the blood pool contrast agent gadofosveset trisodium....

  2. Whole-Body Magnetic Resonance Angiography at 3 Tesla Using a Hybrid Protocol in Patients with Peripheral Arterial Disease

    International Nuclear Information System (INIS)

    Nielsen, Yousef W.; Eiberg, Jonas P.; Logager, Vibeke B.; Schroeder, Torben V.; Just, Sven; Thomsen, Henrik S.

    2009-01-01

    The purpose of this study was to determine the diagnostic performance of 3T whole-body magnetic resonance angiography (WB-MRA) using a hybrid protocol in comparison with a standard protocol in patients with peripheral arterial disease (PAD). In 26 consecutive patients with PAD two different protocols were used for WB-MRA: a standard sequential protocol (n = 13) and a hybrid protocol (n = 13). WB-MRA was performed using a gradient echo sequence, body coil for signal reception, and gadoterate meglumine as contrast agent (0.3 mmol/kg body weight). Two blinded observers evaluated all WB-MRA examinations with regard to presence of stenoses, as well as diagnostic quality and degree of venous contamination in each of the four stations used in WB-MRA. Digital subtraction angiography served as the method of reference. Sensitivity for detecting significant arterial disease (luminal narrowing ≥ 50%) using standard-protocol WB-MRA for the two observers was 0.63 (95%CI: 0.51-0.73) and 0.66 (0.58-0.78). Specificities were 0.94 (0.91-0.97) and 0.96 (0.92-0.98), respectively. In the hybrid protocol WB-MRA sensitivities were 0.75 (0.64-0.84) and 0.70 (0.58-0.8), respectively. Specificities were 0.93 (0.88-0.96) and 0.95 (0.91-0.97). Interobserver agreement was good using both the standard and the hybrid protocol, with κ = 0.62 (0.44-0.67) and κ = 0.70 (0.59-0.79), respectively. WB-MRA quality scores were significantly higher in the lower leg using the hybrid protocol compared to standard protocol (p = 0.003 and p = 0.03, observers 1 and 2). Distal venous contamination scores were significantly lower with the hybrid protocol (p = 0.02 and p = 0.01, observers 1 and 2). In conclusion, hybrid-protocol WB-MRA shows a better diagnostic performance than standard protocol WB-MRA at 3 T in patients with PAD.

  3. Whole-body magnetic resonance angiography at 3 tesla using a hybrid protocol in patients with peripheral arterial disease

    DEFF Research Database (Denmark)

    Nielsen, Yousef W; Eiberg, Jonas P; Logager, Vibeke B

    2009-01-01

    The purpose of this study was to determine the diagnostic performance of 3T whole-body magnetic resonance angiography (WB-MRA) using a hybrid protocol in comparison with a standard protocol in patients with peripheral arterial disease (PAD). In 26 consecutive patients with PAD two different proto...

  4. Ankle Brachial Index <0.9 Underestimates the Prevalence of Peripheral Artery Occlusive Disease Assessed with Whole-Body Magnetic Resonance Angiography in the Elderly

    International Nuclear Information System (INIS)

    Wikstroem, J.; Hansen, T.; Johansson, L.; Lind, L.; Ahlstroem, H.

    2008-01-01

    Background: Whole-body magnetic resonance angiography (WBMRA) permits noninvasive vascular assessment, which can be utilized in epidemiological studies. Purpose: To assess the relation between a low ankle brachial index (ABI) and high-grade stenoses in the pelvic and leg arteries in the elderly. Material and Methods: WBMRA was performed in a population sample of 306 subjects aged 70 years. The arteries below the aortic bifurcation were graded after the most severe stenosis according to one of three grades: 0-49% stenosis, 50-99% stenosis, or occlusion. ABI was calculated for each side. Results: There were assessable WBMRA and ABI examinations in 268 (right side), 265 (left side), and 258 cases (both sides). At least one ≥50% stenosis was found in 19% (right side), 23% (left side), and 28% (on at least one side) of the cases. The corresponding prevalences for ABI <0.9 were 4.5%, 4.2%, and 6.6%. An ABI cut-off value of 0.9 resulted in a sensitivity, specificity, and positive and negative predictive value of 20%, 99%, 83%, and 84% on the right side, and 15%, 99%, 82%, and 80% on the left side, respectively, for the presence of a ≥ 50% stenosis in the pelvic or leg arteries. Conclusion: An ABI <0.9 underestimates the prevalence of peripheral arterial occlusive disease in the general elderly population

  5. Magnetic resonance angiography (MRA)

    International Nuclear Information System (INIS)

    Arlart, I.P.; Guhl, L.

    1992-01-01

    An account is given in this paper of the physical and technical principles underlying the 'time-of-flight' technique for imaging of vessels by magnetic resonance tomography. Major indications for the new procedure of magnetic resonance angiography at present are intracerebral and extracerebral vessels, with digital subtraction angiography quite often being required to cope with minor alterations (small aneurysms, small occlusions). Magnetic resonance angiography and digital subtraction angiography are compared to each other for advantages and disadvantages. Basically, replacement of radiological angiography by magnetic resonance angiography appears to be possible only within limits, since X-ray diagnostics primarily provides morphological information about vessels, whereas flow dynamics is visualized by the 'time-of-flight' technique. (orig.) [de

  6. Magnetic resonance angiography vs. angiography in tetralogy of Fallot.

    Science.gov (United States)

    Rao, Uppalapati Venkateswara; Vanajakshamma, Velam; Rajasekhar, Durgaprasad; Lakshmi, Amancharla Yadagiri; Reddy, Reddivari Niranjan

    2013-08-01

    : To determine whether gadolinium-enhanced three-dimensional magnetic resonance angiography can provide a noninvasive alternative to diagnostic catheterization for evaluation of pulmonary artery anatomy in tetralogy of Fallot. Thirty-five consecutive patients with tetralogy of Fallot, who attended the cardiology outpatient department between January 2008 and December 2009, were included in the study. There were 21 males and 14 females, with a mean age of 9 ± 4.15 years (range, 3-21 years). Thirty-two patients had tetralogy of Fallot with varying severities of valvular and infundibular stenosis. Three patients had tetralogy of Fallot with pulmonary atresia. All patients underwent both cardiac catheterization with X-ray angiography and 3-dimensional magnetic resonance angiography within one month. Measurements of right and left pulmonary arteries and aortopulmonary collaterals were equal by both methods. There was a good correlation between magnetic resonance angiography and catheterization measurements of branch pulmonary arteries. Gadolinium-enhanced three-dimensional magnetic resonance angiography can be used as a reliable noninvasive alternative to X-ray cineangiography for delineation of pulmonary arterial anatomy in sick infants and young children, obviating the need for catheterization.

  7. Magnetic resonance angiography for the head and neck region

    International Nuclear Information System (INIS)

    Aschenbach, R.; Esser, D.

    2004-01-01

    Magnetic resonance angiography is a noninvasive method in vascular imaging using noncontrast- enhanced and contrast-enhanced techniques. The contrast media used in contrast- enhanced magnetic resonance angiography are different from the X-ray contrast media and do not affect the thyroid gland or renal function. In detecting hypervascularized lesions in the head and neck, contrast-enhanced magnetic resonance angiography is the method of choice, which provides an acceptable quality in comparison to digital subtraction angiography. Future developments in magnetic resonance imaging techniques will cause a wider use of magnetic resonance angiography, especially in head and neck imaging. Digital subtraction angiography should therefore only be used in problem cases and for preoperative embolization [de

  8. Your Radiologist Explains Magnetic Resonance Angiography (MRA)

    Medline Plus

    Full Text Available ... Sponsored by Image/Video Gallery Your Radiologist Explains Magnetic Resonance Angiography (MRA) Transcript Welcome to Radiology Info dot ... I’d like to talk with you about magnetic resonance angiography, or as it’s commonly known, MRA. MRA ...

  9. Clinical experience of magnetic resonance angiography in hand surgery

    International Nuclear Information System (INIS)

    Kawabata, Hidehiko; Yasui, Natsuo; Kitano, Motohiro; Sai, Eikoh

    1996-01-01

    Magnetic resonance angiography was performed in fourteen patients with congenital hand abnormalities. A two-dimentional time-of-flight imaging clearly demonstrated presence or absence of the radial, ulnar, and anterior interosseous arteires at forearm. However, smaller arteries such as digital arteries were depressed sometimes. This fact makes clinical application of the method somewhat limited. At present. appropriate applications in orthopaedic fields are evaluation of run-off of the major vessels after trauma or atherosclerotic diseases, venous vascular problems such as thrombophlebitis and aneurysm, and preoperative and post operative evaluation in microsurgery. If more detailed information is required, for example, in differential diagnosis of tumors conventional angiography or digital subtraction angiography is recommended. Because magnetic resonance angiography is non-invasive and does not need anesthesia, it is suitable especially for children. No requirement of contrast medium makes it easy to apply angiography to high risk patients and allergic patients to iodine. Technical advancement in near future will rise up magnetic resonance angiography to a standard evaluation method for vascular problems in orthopaedic fields very soon. (author)

  10. Magnetic resonance angiography of arteriovenous malformation in the brainstem

    Energy Technology Data Exchange (ETDEWEB)

    Oyama, Hirofumi; Kida, Yoshihisa; Kobayashi, Tatsuya; Tanaka, Takayuki; Iwakoshi, Takayasu; Kai, Osamu; Hirose, Mitsuhiko [Komaki City Hospital, Aichi (Japan)

    1993-11-01

    The magnetic resonance (MR) angiography appearance of arteriovenous malformation (AVM) in the tegmentum and pons is described. The interpeduncular perforating branches of the posterior cerebral artery and median pontine branches of the basilar artery were seen more clearly by MR angiography than by conventional angiography. MR angiography was very useful for the follow-up of AVM after stereotactic radiosurgery. (author).

  11. Magnetic resonance angiography of fetal vasculature at 3.0 T

    OpenAIRE

    Neelavalli, Jaladhar; Krishnamurthy, Uday; Jella, Pavan K.; Mody, Swati S.; Yadav, Brijesh K.; Hendershot, Kelly; Hernandez-Andrade, Edgar; Yeo, Lami; Cabrera, Maria D.; Haacke, Ewart M.; Hassan, Sonia S.; Romero, Roberto

    2016-01-01

    Magnetic resonance angiography has not been used much previously for visualizing fetal vessels in utero for reasons that include a contraindication for the use of exogenous contrast agents, maternal respiratory motion and fetal motion. In this work, we report the feasibility of using an appropriately modified clinical time-of-flight magnetic resonance imaging sequence for non-contrast angiography of human fetal and placental vessels at 3.0 T. Using this 2D angiography technique, it is possibl...

  12. Magnetic resonance angiography of fetal vasculature at 3.0 T

    Science.gov (United States)

    Krishnamurthy, Uday; Jella, Pavan K.; Mody, Swati S.; Yadav, Brijesh K.; Hendershot, Kelly; Hernandez-Andrade, Edgar; Yeo, Lami; Cabrera, Maria D.; Haacke, Ewart M.; Hassan, Sonia S.; Romero, Roberto

    2016-01-01

    Magnetic resonance angiography has not been used much previously for visualizing fetal vessels in utero for reasons that include a contraindication for the use of exogenous contrast agents, maternal respiratory motion and fetal motion. In this work, we report the feasibility of using an appropriately modified clinical time-of-flight magnetic resonance imaging sequence for non-contrast angiography of human fetal and placental vessels at 3.0 T. Using this 2D angiography technique, it is possible to visualize fetal vascular networks in late pregnancy. PMID:27189488

  13. Magnetic resonance angiography of fetal vasculature at 3.0 T

    International Nuclear Information System (INIS)

    Neelavalli, Jaladhar; Krishnamurthy, Uday; Yadav, Brijesh K.; Haacke, Ewart M.; Jella, Pavan K.; Hendershot, Kelly; Cabrera, Maria D.; Mody, Swati S.; Hernandez-Andrade, Edgar; Yeo, Lami; Hassan, Sonia S.; Romero, Roberto

    2016-01-01

    Magnetic resonance angiography has not been used much previously for visualizing fetal vessels in utero for reasons that include a contraindication for the use of exogenous contrast agents, maternal respiratory motion and fetal motion. In this work, we report the feasibility of using an appropriately modified clinical time-of-flight magnetic resonance imaging sequence for non-contrast angiography of human fetal and placental vessels at 3.0 T. Using this 2D angiography technique, it is possible to visualize fetal vascular networks in late pregnancy. (orig.)

  14. Magnetic resonance angiography of fetal vasculature at 3.0 T

    Energy Technology Data Exchange (ETDEWEB)

    Neelavalli, Jaladhar; Krishnamurthy, Uday; Yadav, Brijesh K.; Haacke, Ewart M. [Wayne State University School of Medicine, Department of Radiology, Detroit, MI (United States); Wayne State University, Department of Biomedical Engineering, Detroit, MI (United States); Jella, Pavan K.; Hendershot, Kelly; Cabrera, Maria D. [Wayne State University School of Medicine, Department of Radiology, Detroit, MI (United States); Mody, Swati S. [Wayne State University School of Medicine, Department of Radiology, Detroit, MI (United States); Children' s Hospital of Michigan, Department of Radiology, Detroit, MI (United States); Hernandez-Andrade, Edgar; Yeo, Lami; Hassan, Sonia S. [Wayne State University, Department of Obstetrics and Gynecology, Detroit, MI (United States); Perinatology Research Branch, NICHD/NIH/DHHS, Bethesda, MD, and Detroit, MI (United States); Romero, Roberto [Perinatology Research Branch, NICHD/NIH/DHHS, Bethesda, MD, and Detroit, MI (United States); University of Michigan, Department of Obstetrics and Gynecology, Ann Arbor, MI (United States); Michigan State University, Department of Epidemiology and Biostatistics, East Lansing, MI (United States); Wayne State University, Center for Molecular Medicine and Genetics, Detroit, MI (United States)

    2016-12-15

    Magnetic resonance angiography has not been used much previously for visualizing fetal vessels in utero for reasons that include a contraindication for the use of exogenous contrast agents, maternal respiratory motion and fetal motion. In this work, we report the feasibility of using an appropriately modified clinical time-of-flight magnetic resonance imaging sequence for non-contrast angiography of human fetal and placental vessels at 3.0 T. Using this 2D angiography technique, it is possible to visualize fetal vascular networks in late pregnancy. (orig.)

  15. Treatment of arteriovenous malformations with stereotactic radiosurgery employing both magnetic resonance angiography and standard angiography as a database

    International Nuclear Information System (INIS)

    Petereit, D.; Mehta, M.; Turski, P.; Levin, A.; Strother, C.; Mistretta, C.; Mackie, R.; Gehring, M.; Kubsad, S.; Kinsella, T.

    1993-01-01

    Twenty-one arteriovenous malformations were prospectively evaluated using magnetic resonance angiography, compare it to stereotactic angiography, employ magnetic resonance angiography in follow-up, and semiquanitfy flow. A correlative evaluation between flow and response to stereotactic radiosurgery was carried out. Phase contrast angiograms were obtained at flow velocities of 400, 200, 100, 60 and 20 cm/sec. The fractionated velocities provided images that selectively demonstrated the arterial and venous components of the arteriovenous malformations. Qualitative assessment of the velocity within the arteriovenous malformations and the presence of fistulae were also determined by multiple velocity images. In addition, 3-dimensional time-of-flight magnetic resonance angiograms were obtained to define the exact size and shape of the nidus. This technique also permitted evaluation of the nidus and feeding arteries for the the presence of low flow aneurysms. Correlation between the two imaging modalities was carried out by subjective and semiquantitative estimation of flow velocity and estimation of nidus size. The following velocity parameters were employed: fast, intermediate, slow, and none. Early analysis suggests that slower flowing arteriovenous malformations may obliterate faster after stereotactic radiosurgery an flow parameters should be employed to predict response. In conclusion, magnetic resonance angiography permits semiquantitative flow velocity assessment and may therefore be superior to stereotactic angiography. An additional advantage of magnetic resonance angiography is the generation of serial transverse images which can replace the conventional CT scan employed for stereotactic radiosurgery treatment planning. A single diagnostic test may therefore be used for diagnosis, radiosurgical treatment planning, follow-up, and treatment selection by identifying patients likely to respond early to radiosurgical management

  16. A comparison between magnetic resonance angiography at 3 teslas (time-of-flight and contrast-enhanced and flat-panel digital subtraction angiography in the assessment of embolized brain aneurysms

    Directory of Open Access Journals (Sweden)

    Guilherme S. Nakiri

    2011-01-01

    Full Text Available PURPOSE: To compare the time-of-flight and contrast-enhanced- magnetic resonance angiography techniques in a 3 Tesla magnetic resonance unit with digital subtraction angiography with the latest flat-panel technology and 3D reconstruction in the evaluation of embolized cerebral aneurysms. INTRODUCTION: Many embolized aneurysms are subject to a recurrence of intra-aneurismal filling. Traditionally, imaging surveillance of coiled aneurysms has consisted of repeated digital subtraction angiography. However, this method has a small but significant risk of neurological complications, and many authors have advocated the use of noninvasive imaging methods for the surveillance of embolized aneurysms. METHODS: Forty-three aneurysms in 30 patients were studied consecutively between November 2009 and May 2010. Two interventional neuroradiologists rated the time-of-flight-magnetic resonance angiography, the contrast-enhanced-magnetic resonance angiography, and finally the digital subtraction angiography, first independently and then in consensus. The status of aneurysm occlusion was assessed according to the Raymond scale, which indicates the level of recanalization according to degrees: Class 1: excluded aneurysm; Class 2: persistence of a residual neck; Class 3: persistence of a residual aneurysm. The agreement among the analyses was assessed by applying the Kappa statistic. RESULTS: Inter-observer agreement was excellent for both methods (K = 0.93; 95 % CI: 0.84-1. Inter-technical agreement was almost perfect between time-of-flight-magnetic resonance angiography and digital subtraction angiography (K = 0.98; 95 % CI: 0.93-1 and between time-of-flight-magnetic resonance angiography and contrast-enhanced-magnetic resonance angiography (K = 0.98; 95% CI: 0.93-1. Disagreement occurred in only one case (2.3%, which was classified as Class I by time-of-flight-magnetic resonance angiography and Class II by digital subtraction angiography. The agreement between

  17. Radiosurgery for arteriovenous malformations based on magnetic resonance angiography

    International Nuclear Information System (INIS)

    Mehta, Minesh; Kubsad, Shrikant; Petereit, Daniel; Turski, Patrick; Levin, Allan; Kinsella, Timothy

    1993-01-01

    Magnetic Resonance Angiography (MRA) was performed to establish its feasibility, compare it with standard angiography (SA), employ MRA in follow-up and semiquantify AVM flow velocity (FV). A correlative evaluation between flow velocity and response to stereotactic radiosurgery was also attempted. (author). 8 refs., 1 tab

  18. Magnetic resonance angiography of arteriovenous malformation in the thalamus

    Energy Technology Data Exchange (ETDEWEB)

    Oyama, Hirofumi; Kida, Yoshihisa; Kobayashi, Tatsuya; Tanaka, Takayuki; Iwakoshi, Takayasu; Kai, Osamu; Hirose, Mitsuhiko [Komaki City Hospital, Aichi (Japan)

    1993-11-01

    A comparative study of magnetic resonance angiography and conventional angiography of arteriovenous malformation in the thalamus showed that both methods clearly visualized the feeding arteries: perforating branches of the posterior cerebral artery, posterior choroidal artery and lenticulostriate artery. Draining veins such as the internal cerebral vein were also demonstrated well. (author).

  19. Your Radiologist Explains Magnetic Resonance Angiography (MRA)

    Medline Plus

    Full Text Available ... Disorders Video: The Basketball Game: An MRI Story Radiology and You Sponsored by Image/Video Gallery Your ... Explains Magnetic Resonance Angiography (MRA) Transcript Welcome to Radiology Info dot org Hello, I’m Dr. Elliot ...

  20. Your Radiologist Explains Magnetic Resonance Angiography (MRA)

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    Full Text Available ... An MRI Story Radiology and You Sponsored by Image/Video Gallery Your Radiologist Explains Magnetic Resonance Angiography ( ... posted: How to Obtain and Share Your Medical Images Movement Disorders Video: The Basketball Game: An MRI ...

  1. Your Radiologist Explains Magnetic Resonance Angiography (MRA)

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    Full Text Available ... mild sedative prior to the examination. For more information about Magnetic Resonance Angiography of MRA or any ... Inc. (RSNA). To help ensure current and accurate information, we do not permit copying but encourage linking ...

  2. Your Radiologist Explains Magnetic Resonance Angiography (MRA)

    Medline Plus

    Full Text Available ... with you about magnetic resonance angiography, or as it’s commonly known, MRA. MRA is a noninvasive test ... of the major blood vessels throughout your body. It may be performed with or without contrast material ...

  3. Your Radiologist Explains Magnetic Resonance Angiography (MRA)

    Medline Plus

    Full Text Available ... talk with you about magnetic resonance angiography, or as it’s commonly known, MRA. MRA is a noninvasive ... possibility that you’re pregnant tell your doctor as well. On the day of your exam, it’s ...

  4. Magnetic resonance angiography for patients with positional vertigo

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Toru; Tominaga, Satoru; Fujiki, Hiroya (Takarazuka City Hospital, Hyogo (Japan)); Kumoi, Takeo

    1993-11-01

    Magnetic resonance angiography (MRA) can image the blood vessels without invasion. Using MRA, we studied the vascular morphology of the vertebral artery in patients with positional nystagmus and vertigo. Fifteen patients without vestibular disorder such as benign positional vertigo were examined. Six cases underwent conventional vertebral angiography, including digital subtraction angiography (DSA) for comparison with MRA. In all cases. we observed the vertebral artery from the bifurcation to the basilar artery with MRA. In 12 cases, abnormal findings of elongation, bending, narrowing or obstruction of the vertebral artery were found. In five cases, arterial compression and elongation increased in association with head rotation. A difference in the vessel diameter on each side was observed in 4 cases. Accordingly, some abnormal vessels were found in 14 of 15 cases in our study. This rate was very close to previous results obtained with conventional angiography. In two cases, MRA findings differed from conventional angiography due to peculiar artifacts of MRA. Therefore, MRA may be the first choice for the patients with vertigo, followed by conventional angiography, if necessary. (author).

  5. Magnetic resonance angiography for patients with positional vertigo

    International Nuclear Information System (INIS)

    Seo, Toru; Tominaga, Satoru; Fujiki, Hiroya; Kumoi, Takeo.

    1993-01-01

    Magnetic resonance angiography (MRA) can image the blood vessels without invasion. Using MRA, we studied the vascular morphology of the vertebral artery in patients with positional nystagmus and vertigo. Fifteen patients without vestibular disorder such as benign positional vertigo were examined. Six cases underwent conventional vertebral angiography, including digital subtraction angiography (DSA) for comparison with MRA. In all cases. we observed the vertebral artery from the bifurcation to the basilar artery with MRA. In 12 cases, abnormal findings of elongation, bending, narrowing or obstruction of the vertebral artery were found. In five cases, arterial compression and elongation increased in association with head rotation. A difference in the vessel diameter on each side was observed in 4 cases. Accordingly, some abnormal vessels were found in 14 of 15 cases in our study. This rate was very close to previous results obtained with conventional angiography. In two cases, MRA findings differed from conventional angiography due to peculiar artifacts of MRA. Therefore, MRA may be the first choice for the patients with vertigo, followed by conventional angiography, if necessary. (author)

  6. Magnetic resonance angiography in meningovascular syphilis

    Energy Technology Data Exchange (ETDEWEB)

    Gallego, J [Servicio de Neurologia, Hospital de Navarra and Pamplona Univ. Hospital (Spain); Soriano, G [Servicio de Neurologia, Hospital de Navarra and Pamplona Univ. Hospital (Spain); Zubieta, J L [Servicio de Neuroradiologia, Hospital de Navarra and Pamplona Univ. Hospital (Spain); Delgado, G [Servicio de Neurologia, Hospital de Navarra and Pamplona Univ. Hospital (Spain); Villanueva, J A [Servicio de Neurologia, Hospital de Navarra and Pamplona Univ. Hospital (Spain)

    1994-04-01

    Meningovascular neurosyphilis (MN) is an unusual cause of stroke in young adults. The clinical manifestations include prodromal symptoms weeks or months before definitive stroke. The diagnosis is based on clinical findings and examination of the serum and cerebrospinal fluid. We report a case of MN with basilar artery irregularities demonstrated by magnetic resonance angiography. (orig.)

  7. Magnetic resonance angiography in meningovascular syphilis

    International Nuclear Information System (INIS)

    Gallego, J.; Soriano, G.; Zubieta, J.L.; Delgado, G.; Villanueva, J.A.

    1994-01-01

    Meningovascular neurosyphilis (MN) is an unusual cause of stroke in young adults. The clinical manifestations include prodromal symptoms weeks or months before definitive stroke. The diagnosis is based on clinical findings and examination of the serum and cerebrospinal fluid. We report a case of MN with basilar artery irregularities demonstrated by magnetic resonance angiography. (orig.)

  8. Vascular anatomy in angiography for magnetic resonance

    International Nuclear Information System (INIS)

    Charry Lopez, Marco Luciano; Rivera Gomez, Juan Enrique

    1998-01-01

    A review of basic anatomical concepts and main variants, as well as some anatomical anomalies of the central nervous system vascularity, these concepts are considered essential for the interpretation of magnetic resonance angiography with time-of-flight (TOF) and phase-contrast (PC) methods

  9. Comparison of magnetic resonance angiography and conventional angiography in sickle cell disease: clinical significance and realibility

    International Nuclear Information System (INIS)

    Kandeel, A.Y.; Zimmerman, R.A.; Ohene-Frempong, K.

    1996-01-01

    We retrospectively reviewed the medical records and conventional angiograms of 21 patients with known sickle cell disease, who underwent a total of 50 magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) studies. MRA and conventional angiography were assessed separately for evidence of stenosis or occulusion. Follow up MRI/MRA studies were also assessed for evidence of progression, regression or stability of the disease in these patients. In the carotid circulation, MRA made the correct diagnosis in 85% of the vessels evaluated with a sensitivity of 80.5% and a specificity of 94%. MRA was also found to show evidence of disease progression, more often than did MRI or the clinical condition of the patients. (orig.)

  10. Comparison of contrast-enhanced magnetic resonance angiography and conventional pulmonary angiography for the diagnosis of pulmonary embolism : a prospective study

    NARCIS (Netherlands)

    Oudkerk, M; van Beek, EJR; Wielopolski, P; van Ooijen, PMA; Brouwers-Kuyper, EMJ; Bongaerts, AHH; Berghout, A

    2002-01-01

    Background Diagnostic strategies for pulmonary embolism are complex and consist of non-invasive diagnostic tests done to avoid conventional pulmonary angiography as much as possible. We aimed to assess the diagnostic accuracy of magnetic resonance angiography (MRA) for the diagnosis of pulmonary

  11. Catheter Angiography

    Medline Plus

    Full Text Available ... is performed using: x-rays with catheters computed tomography (CT) magnetic resonance imaging (MRI) In catheter angiography, ... tumor; this is called superselective angiography. Unlike computed tomography (CT) or magnetic resonance (MR) angiography , use of ...

  12. Magnetic resonance angiography of fetal vasculature at 3.0 T.

    Science.gov (United States)

    Neelavalli, Jaladhar; Krishnamurthy, Uday; Jella, Pavan K; Mody, Swati S; Yadav, Brijesh K; Hendershot, Kelly; Hernandez-Andrade, Edgar; Yeo, Lami; Cabrera, Maria D; Haacke, Ewart M; Hassan, Sonia S; Romero, Roberto

    2016-12-01

    Magnetic resonance angiography has not been used much previously for visualizing fetal vessels in utero for reasons that include a contraindication for the use of exogenous contrast agents, maternal respiratory motion and fetal motion. In this work, we report the feasibility of using an appropriately modified clinical time-of-flight magnetic resonance imaging sequence for non-contrast angiography of human fetal and placental vessels at 3.0 T. Using this 2D angiography technique, it is possible to visualize fetal vascular networks in late pregnancy. • 3D-visualization of fetal vasculature is feasible using non-contrast MRA at 3.0 T. • Visualization of placental vasculature is also possible with this method. • Fetal MRA can serve as a vascular localizer for quantitative MRI studies. • This method can be extended to 1.5 T.

  13. Catheter Angiography

    Medline Plus

    Full Text Available ... is performed using: x-rays with catheters computed tomography (CT) magnetic resonance imaging (MRI) In catheter angiography, a ... tumor; this is called superselective angiography. Unlike computed tomography (CT) or magnetic resonance (MR) angiography , use of a ...

  14. Catheter Angiography

    Medline Plus

    Full Text Available ... using: x-rays with catheters computed tomography (CT) magnetic resonance imaging (MRI) In catheter angiography, a thin plastic ... called superselective angiography. Unlike computed tomography (CT) or magnetic resonance (MR) angiography , use of a catheter makes it ...

  15. Prominent porto-systemic collateral pathways in patients with portal hypertension: demonstration by gadolinium-enhanced magnetic resonance angiography

    International Nuclear Information System (INIS)

    Caldana, Rogerio Pedreschi; Bezerra, Alexandre Araujo Sergio; Cecin, Alexnadre Oliveira; Souza, Luis Ronan Marques Ferreira de; Goldman, Susan Menasce; D'Ippolito, Giuseppe; Szejnfeld, Jacob

    2003-01-01

    To demonstrate the usefulness of gadolinium-enhanced magnetic resonance angiography in the evaluation of prominent porto-systemic collateral pathways. We reviewed the images from 40 patients with portal hypertension studied with gadolinium-enhanced magnetic resonance angiography and selected illustrative cases of prominent porto-systemic collateral pathways. The scans were performed using high field equipment (1.5 Tesla) and a 3 D volume technique. Image were obtained after intravenous injection of paramagnetic contrast media using a power injector. Magnetic resonance angiography demonstrated with precision the porto-systemic collateral pathways, particularly when investigating extensive territories or large vessels. The cases presented show the potential of this method in the investigation of patients with portal hypertension. Gadolinium-enhanced magnetic resonance angiography is a useful method for the evaluation of patients with portal hypertension and prominent collateral pathways. (author)

  16. Parenchymal abnormalities in cerebral venous thrombosis: findings of magnetic resonance imaging and magnetic resonance angiography

    International Nuclear Information System (INIS)

    Ferreira, Clecia Santos; Pellini, Marcos; Boasquevisque, Edson; Souza, Luis Alberto M. de

    2006-01-01

    Objective: to determine the frequency and localization of parenchymal abnormalities in cerebral venous thrombosis on magnetic resonance imaging and magnetic resonance angiography as well as their correlation with the territory and affected venous drainage. Materials and methods: retrospective analysis (1996 to 2004) of 21 patients (3 male and 18 female) age range between 3 and 82 years (mean 40 years, median 36 years) with clinical and radiological diagnosis of cerebral venous thrombosis on magnetic resonance imaging and magnetic resonance angiography in 2D PC, 3D PC and contrast-enhanced 3D TOF sequences. The statistical analysis was performed with the qui-square test. Four patients had follow-up exams and three patients underwent digital subtraction angiography. Results: main predisposing factors were: infection, use of oral contraceptives, hormone replacement therapy and collagenosis. Predominant symptoms included: focal deficit, headache, alteration of consciousness level and seizures. Most frequent parenchymal manifestations were: cortical/subcortical edema or infarct, venous congestion and collateral circulation, meningeal enhancement and thalamic and basal ganglia edema or infarct. Occlusion occurred mainly in superior sagittal, left transverse, left sigmoid and straight sinuses. Cavernous sinus and cortical veins thrombosis are uncommon events. Conclusion: cerebral venous thrombosis is an uncommon cause of stroke, with favorable prognosis because of its reversibility. Diagnosis is highly dependent on the radiologist capacity to recognize the presentations of this disease, principally in cases where the diagnosis is suggested by parenchymal abnormalities rather than necessarily by visualization of the thrombus itself. An accurate and rapid diagnosis allows an immediate treatment, reducing the morbidity and mortality rates. (author)

  17. Symptomatic middle cerebral artery stenosis and occlusion. Comparison of three-dimensional time-of-flight magnetic resonance angiography with conventional angiography

    Energy Technology Data Exchange (ETDEWEB)

    Sawada, Motoshi; Yano, Hirohito; Shinoda, Jun; Funakoshi, Takashi [Daiyukai General Hospital, Ichinomiya, Aichi (Japan); Kumagai, Morio

    1994-10-01

    The usefulness of magnetic resonance (MR) angiography using the three-dimensional time-of-flight method for the characterization of symptomatic middle cerebral artery (MCA) occlusive lesions was evaluated in 10 patients with MCA occlusion and 10 with MCA stenosis. All lesions were symptomatic and documented by conventional angiography. There was no false-negative MR angiogram that failed to demonstrate the MCA occlusive lesion. MR angiography correctly evaluated the location of lesions and the difference between stenosis and occlusion. Stenosis appeared as a focal signal loss (<1.0cm) of the MCA at the site of stenosis, and occlusion as a complete signal loss of the MCA distal to the site of occlusion. However, MR angiography could not distinguish diffuse stenosis and one point stenosis demonstrated by conventional angiography. MR angiography is a useful noninvasive diagnostic method for evaluating occlusive lesions of the MCA in symptomatic patients. (author).

  18. Clinical application of magnetic resonance coronary angiography

    International Nuclear Information System (INIS)

    Murakami, Akihiko; Onoe, Teruyuki; Kodera, Akifumi; Ohtsuki, Tetsuya; Shiomi, Akio; Ida, Masaaki; Sawada, Takahisa

    1999-01-01

    We performed the magnetic resonance coronary angiography (MRCA) in the cases which underwent coronary angiography (CAG) and obtained images were compared. Lesion with significant constriction more than 75% on CAG were determined as abnormal findings on MRCA, however, lesions with about 50% constriction were as the normal findings. On the assessment of the re-constriction after PTCA, the changes in signal were found in about half of cases. This may come from the contribution of flexion lesions, the difficulty to assess moderate constriction after PTCA, etc. For the anomalous aortic origin of coronary artery, peripheral large vessels could be simultaneously imaged by MRCA and be also assessed among their clear spatial relationship. Although MRCA has some problems on the assessment for flexion or moderate constriction, these results suggested that MRCA is useful to clinical application as the non-invasive examination. (K.H.)

  19. Non-contrast enhanced magnetic resonance angiography techniques in candidates for kidney transplantation: A comparative study

    International Nuclear Information System (INIS)

    Blankholm, Anne Dorte; Ginnerup-Pedersen, Bodil; Stausbøl-Grøn, Brian; Haislund, Margit; Laustsen, Sussie; Ringgaard, Steffen

    2013-01-01

    Aim: Detailed knowledge of vessel status in potential candidates for kidney transplantation is essential for the surgeon. Contrast enhanced magnetic resonance angiography has previously been used intensively for assessing this, but the discovery that use of gadolinium based contrast agents in magnetic resonance imaging can cause Nephrogenic Systemic Fibrosis in patients suffering from severe kidney disease has lead to renewed interest in non-contrast enhanced magnetic resonance angiography. The aim of this study was to find a non-contrast enhanced magnetic resonance angiography method for preoperative evaluation of the pelvic vessels prior to kidney transplantation, providing a sufficient image quality. Method: In a prospective study we consecutively included 54 patients undergoing examinations prior to kidney transplantation. The patients were examined with the following magnetic resonance angiography sequences: A 2D Time of flight (n = 54), 3D Time of flight (n = 52) patients, 3D Phase Contrast (n = 54), 3D Balanced Steady State Free Precession (n = 52) and a 2D TRiggered Angiography Non-Contrast Enhanced (TRANCE) (a Spin Echo sequence with subtraction) (n = 48). The sequences were evaluated with respect to contrast, diagnostic performance and artefact burden. Results: Evaluating contrast, 3D Phase Contrast was significantly better than 2D Time of flight (p 0.2). The 2D Time of flight was significantly better than the other sequences (p < 0.001) in all cases. The artefact score was lowest for the Phase Contrast images and significantly superior to the 2D Time of flight (p < 0.005). The 2D Time of flight was significantly better than the three other sequences (p < 0.001) in all cases. Conclusion: Non-contrast enhanced magnetic resonance angiography offers a safe preoperative examination for assessment of vessel status before kidney transplantation. A combination of 2D Time of flight and 3D Phase Contrast acquisitions is recommended and can be performed within a

  20. Magnetic resonance angiography (MRA) of the circle of Willis: a prospective comparison with conventional angiography in 54 subjects

    International Nuclear Information System (INIS)

    Patrux, B.; Laissy, J.P.; Jouini, S.; Kawiecki, W.; Coty, P.; Thiebot, J.

    1994-01-01

    We prospectively correlated the findings of magnetic resonance angiography (MRA) with those of transfemoral four-vessel angiography in 54 patients to investigate the direction of flow within the circle of Willis. Our primary goal was to assess the direction of flow using the size of the vessel and signal intensity, without saturation techniques. Analysis of the circle of Willis, especially the communicating arteries, was performed double-blind by two groups of two radiologists. Three types of arteries were identified: high flow or cross-cerebral circulation, patent and nonvisualised arteries. Cerebral angiography was the standard for comparison between the two methods. MRA did not reveal any arteries invisible on angiography, thus providing a specificity of 100%. The sensitivity of MRA was 89.2% for the anterior and 81.3% for the posterior communicating arteries, and 100% for the anterior, middle and posterior cerebral arteries. MRA was shown to be a useful technique for the assessment of patency of the circle of Willis. (orig.)

  1. Magnetic resonance angiography (MRA) of the circle of Willis: a prospective comparison with conventional angiography in 54 subjects

    Energy Technology Data Exchange (ETDEWEB)

    Patrux, B. (Neuroradiology, CHU Charles Nicolle, Rouen (France)); Laissy, J.P. (Neuroradiology, CHU Charles Nicolle, Rouen (France) Dept. of Radiology, CHU Bichat, Paris (France)); Jouini, S. (Neuroradiology, CHU Charles Nicolle, Rouen (France)); Kawiecki, W. (Siemens Medical Systems, Saint-Denis (France)); Coty, P. (Neuroradiology, CHU Charles Nicolle, Rouen (France)); Thiebot, J. (Neuroradiology, CHU Charles Nicolle, Rouen (France))

    1994-04-01

    We prospectively correlated the findings of magnetic resonance angiography (MRA) with those of transfemoral four-vessel angiography in 54 patients to investigate the direction of flow within the circle of Willis. Our primary goal was to assess the direction of flow using the size of the vessel and signal intensity, without saturation techniques. Analysis of the circle of Willis, especially the communicating arteries, was performed double-blind by two groups of two radiologists. Three types of arteries were identified: high flow or cross-cerebral circulation, patent and nonvisualised arteries. Cerebral angiography was the standard for comparison between the two methods. MRA did not reveal any arteries invisible on angiography, thus providing a specificity of 100%. The sensitivity of MRA was 89.2% for the anterior and 81.3% for the posterior communicating arteries, and 100% for the anterior, middle and posterior cerebral arteries. MRA was shown to be a useful technique for the assessment of patency of the circle of Willis. (orig.)

  2. Magnetic resonance angiography of the pediatric abdomen and pelvis: techniques and imaging findings.

    Science.gov (United States)

    Sada, David M; Vellody, Ranjith; Liu, Peter S

    2013-11-01

    Although traditional catheter-based angiography has been the gold standard for pediatric abdominal and pelvic vascular imaging for the past several decades, advances in magnetic resonance angiography (MRA) have made it a viable alternative. MRA offers several advantages in that it is noninvasive, can be performed without ionizing radiation, and does not necessarily rely on contrast administration. The ability of modern MRA techniques to define variant vascular anatomy and detect vascular disease may obviate traditional angiography in some patients. Copyright © 2013 Elsevier Inc. All rights reserved.

  3. Magnetic resonance angiography of the cerebral vessels

    International Nuclear Information System (INIS)

    Peters, P.E.; Bongartz, G.; Drews, C.

    1990-01-01

    In a prospective study involving 52 patients, magnetic resonance angiography (MRA) was compared with arterial digital subtraction angiography (IA-DSA). MRA was performed within three days of the IA-DSA. It was carried out without knowledge of the findings on IA-DSA. Of 38 stenoses of the carotid arteries or their branches, demonstrated by IA-DSA, 33 could be seen on MRA; in four cases the stenosis was outside the imaging area of the coil. Sixteen out of 17 carotid occlusions were diagnosed by MRA. There was one false positive. In the vertebral artery territory, eleven out of 13 stenoses and three out of four occlusions were diagnosed by MRA. In evaluating the degree of stenosis, there was agreement in only 16 out of 33 cases. MRA over-estimated the severity of stenoses in 15 cases and underestimated it in two. MRA is a new non-invasive method in the diagnosis of cerebro-vascular disease which must be evaluated by further studies. (orig.) [de

  4. Bolus characteristics based on Magnetic Resonance Angiography

    Directory of Open Access Journals (Sweden)

    Bi Xiaoming

    2006-10-01

    Full Text Available Abstract Background A detailed contrast bolus propagation model is essential for optimizing bolus-chasing Computed Tomography Angiography (CTA. Bolus characteristics were studied using bolus-timing datasets from Magnetic Resonance Angiography (MRA for adaptive controller design and validation. Methods MRA bolus-timing datasets of the aorta in thirty patients were analyzed by a program developed with MATLAB. Bolus characteristics, such as peak position, dispersion and bolus velocity, were studied. The bolus profile was fit to a convolution function, which would serve as a mathematical model of bolus propagation in future controller design. Results The maximum speed of the bolus in the aorta ranged from 5–13 cm/s and the dwell time ranged from 7–13 seconds. Bolus characteristics were well described by the proposed propagation model, which included the exact functional relationships between the parameters and aortic location. Conclusion The convolution function describes bolus dynamics reasonably well and could be used to implement the adaptive controller design.

  5. Magnetic resonance angiography: Physical principles and clinical applications

    International Nuclear Information System (INIS)

    Hausmann, R.; Mueller, E.

    1992-01-01

    Within the last four years magnetic resonance angiography (MRA) developed very rapidly towards a well accepted screening technique for vascular examinations as a fast add-on to conventional MR. This review describes the basic physical principles as well as the different methods like time-of-flight and phase-sensitive MRA for visualization of blood vessels. Different applications of 3D, 2D sequential and 3D multivolume MRA are shown from various regions of the head and body. A short outlock to quantitative flow measurments is given in the last chapter including some interesting applications of these techniques which show the still expanding potential of magnetic resonance. (orig.) [de

  6. Three-dimensional magnetic resonance coronary angiography using a new blood pool contrast agent : Initial experience

    NARCIS (Netherlands)

    Bedaux, WLF; Hofman, MBM; Wielopolski, PA; de Cock, CC; Hoffmann, [No Value; Oudkerk, M; de Feyter, PJ; van Rossum, AC

    2002-01-01

    Objective: The aim of this feasibility study was to assess the effect of a new blood pool contrast agent on magnetic resonance coronary angiography (MRCA) in patients suspected of having coronary artery disease. Methods: Nine patients referred for diagnostic x-ray coronary, angiography in the

  7. Comparison between digital subtraction angiography and magnetic resonance angiography in investigation of nonlacunar ischemic stroke in young patients: preliminary results.

    Science.gov (United States)

    Conforto, Adriana Bastos; Fregni, Felipe; Puglia, Paulo; Leite, Claudia da Costa; Yamamoto, Fabio Iuji; Coracini, Karen F; Scaff, Milberto

    2006-06-01

    We preliminarily investigated the relevance of performing digital subtraction angiography (DSA) in addition to magnetic resonance angiography (MRA) in definition of ischemic stroke etiology in young patients. DSAs and MRAs from 17 young patients with nonlacunar ischemic stroke were blindly analyzed and their impact on stroke management was evaluated. Etiologies were the same considering results of either DSA or MRA in 12/17 cases. In 15/17 patients no changes would have been made in treatment, regardless of the modality of angiography considered. These preliminary results suggest that DSA may be redundant in two thirds of ischemic strokes in young patients. Further larger prospective studies are necessary to determine indications of DSA in this age group.

  8. Catheter Angiography

    Medline Plus

    Full Text Available ... Z Catheter Angiography Catheter angiography uses a catheter, x-ray imaging guidance and an injection of contrast material ... vessels in the body. Angiography is performed using: x-rays with catheters computed tomography (CT) magnetic resonance imaging ( ...

  9. Three-dimensional magnetic resonance angiography of vascular lesions in children.

    Science.gov (United States)

    Katayama, H; Shimizu, T; Tanaka, Y; Narabayashi, I; Tamai, H

    2000-01-01

    We applied three-dimensional (3D) magnetic resonance (MR) angiography to vascular lesions in children and evaluated the clinical usefulness of this technique. Ten patients, whose ages ranged from 1 month to 16 years, underwent 3D MR angiography for 12 vascular lesions, including lesions in seven pulmonary arteries, two thoracic aortae, a pair of renal arteries, and one iliac artery. Three-dimensional MR angiography was performed with body-or pelvic-phased array coils on a 1.5-T scanner using fast spoiled gradient echo sequence. Data were acquired with the following parameters: TE, 1.9 ms; TR, 10.1 ms; flip angle, 20-60 degrees ; 1 or 2 NEX; field of view, 24-48 x 18-40 cm; matrix, 256 or 512 x 128 or 256; slice thickness, 1.2-7.5 mm; and 12, 28, or 60 partitions. Vascular imaging was enhanced with 20% gadolinium-diethylenetriaminepentaacetic acid. The examination was performed under breath-holding in six patients and with shallow breathing in four patients. In a comparative study with other noninvasive methods, 3D MR angiography was superior in seven of nine cases to other noninvasive examinations and in two cases, all methods evaluated the lesions. Furthermore, six cases were compared with conventional angiography. In five of the six cases, both methods depicted the lesions similarly, and in one case, MR angiography was more effective. A quantitative comparison of vascular diameter in the MR image was made with that in the conventional angiographic image. The correlation between them was excellent: y = 1.145x-2.090 (r = 0.987; P children.

  10. Comparison of gadofosveset-enhanced three-dimensional magnetic resonance angiography with digital subtraction angiography for lower-extremity peripheral arterial occlusive disease

    International Nuclear Information System (INIS)

    Grijalba, Fermin Urtasun; Esandi, Mercedes Ciriza

    2010-01-01

    Background: Minimally invasive imaging techniques are increasingly used for clinical decision making in patients with peripheral arterial occlusive disease (PAOD). Purpose: To assess whether gadofosveset-enhanced three-dimensional (3D) magnetic resonance (MR) angiography could replace digital subtraction angiography (DSA) for the evaluation of lower-extremity PAOD. Material and Methods: Thirty patients with symptomatic PAOD underwent prospectively both MR angiography and DSA. Gadofosveset-enhanced 3D MR angiography was performed on a 1.5T system equipped with a peripheral angio matrix coil. Four blinded observers independently analyzed MR angiograms and DSA images. The lower arterial vascular system was divided into three anatomic segments (aortoiliac, femoropopliteal, infrapopliteal) for review. The status of each segment was graded as normal, stenosis less than 50%, stenosis greater than 50%, or occluded and/or aneurismatic. Principal and secondary lesions were reported. Results: Although interobserver agreement for both was excellent, it was higher for DSA (?=0.92) than for MR angiography (?=0.86) for reporting the principal and secondary lesions in all segments. For different anatomic locations, the interobserver agreement of MR angiography and DSA was as follows: aortoiliac (?=0.93, k=0.95), femoropopliteal (?=0.86, k=0.90), and infrapopliteal (?=0.78, k=0.85). The lowest agreement was found for MR angiography on infrapopliteal segments (?=0.78). In four (13.3%) cases, MR angiography showed lesions that were not found by DSA. Five (16.6%) aneurysm cases, not observed by DSA, were shown by MR angiography. Conclusion: Gadofosveset-enhanced 3D MR angiography can be proposed for first-line imaging in the management of lower-limb PAOD patients and permits the selective use of DSA as a second-line examination when MR angiography fails or in an endovascular approach

  11. Fusion of magnetic resonance angiography and magnetic resonance imaging for surgical planning for meningioma. Technical note

    International Nuclear Information System (INIS)

    Kashimura, Hiroshi; Ogasawara, Kuniaki; Arai, Hiroshi

    2008-01-01

    A fusion technique for magnetic resonance (MR) angiography and MR imaging was developed to help assess the peritumoral angioarchitecture during surgical planning for meningioma. Three-dimensional time-of-flight (3D-TOF) and 3D-spoiled gradient recalled (SPGR) datasets were obtained from 10 patients with intracranial meningioma, and fused using newly developed volume registration and visualization software. Maximum intensity projection (MIP) images from 3D-TOF MR angiography and axial SPGR MR imaging were displayed at the same time on the monitor. Selecting a vessel on the real-time MIP image indicated the corresponding points on the axial image automatically. Fusion images showed displacement of the anterior cerebral or middle cerebral artery in 7 patients and encasement of the anterior cerebral arteries in I patient, with no relationship between the main arterial trunk and tumor in 2 patients. Fusion of MR angiography and MR imaging can clarify relationships between the intracranial vasculature and meningioma, and may be helpful for surgical planning for meningioma. (author)

  12. Magnetic resonance angiography of cerebral developmental venous anomalies: its role in differential diagnosis

    International Nuclear Information System (INIS)

    Ostertun, B.; Solymosi, L.

    1993-01-01

    CT, MRI and contrast angiography of 20 patients with 21 developmental venous anomalies (DVAs), so-called venous angiomas, were compared with magnetic resonance angiography employing a two-dimensional time-of-flight technique (2D-MRA). MRA was diagnostic in 17 DVAs, when both the primary 2D slices and the maximum-intensity-protection images were read. Contrast angiography still provides the best visualization of both DVA components: dilated medullary veins and transcerebral draining vein; however, it is an invasive procedure and delivers no information about brain parenchyma. We regard MRI as necessary in cases with a suspected DVA because of the high rate of association with cavernomas: 33% in this study. Acute neurological symptoms were caused by haemorrhage from an associated cavernoma and not from the DVA in 4 such cases. Thus MRA combined with MRI obviates angiography in most cases and offers a noninvasive diagnostic strategy adequate for DVAs. (orig.)

  13. Detection and characterization of intracranial aneurysms: magnetic resonance angiography versus digital subtraction angiography

    International Nuclear Information System (INIS)

    Shahzad, R.; Younas, F.

    2011-01-01

    Objective: To compare magnetic resonance angiography (MRA) with Intra-arterial digital subtraction angiography (IA-DSA) in detection and characterization of intracranial aneurysms. Study Design: Comparative cross-sectional study. Place and Duration of Study: Department of Diagnostic Imaging, Lahore General Hospital, Lahore, from January to June 2007. Methodology: Thirty patients presented with aneurysmal subarachnoid haemorrhage (SAH) and focal neurological signs were selected by convenience sampling. Three dimensional time of flight (3D TOF) MRA using maximum intensity projection (MIP) was performed on all patients along with DSA. Results of 3D TOF MRA were compared with those of IA-DSA taking IA-DSA as Gold standard. Results: Out of 30 patients 14 (46.7%) were males and 16 (53.3%) were females with mean age of 41+-14.1 years. MRA detected 29 out of 30 aneurysmal lesions with sensitivity of 96.7%. Regarding characterization of aneurysms results of MRA were comparable to those of IA-DSA. Conclusion: 3D TOF MRA technique showed a high sensitivity in this study. This technique can be used as a non-invasive screening test for intracranial aneurysms and as a suitable alternative primary examination to IA-DSA prior to aneurysmal surgery. (author)

  14. Magnetic Resonance Angiography in the Pig using Hyperpolarized Water

    DEFF Research Database (Denmark)

    Lipsø, Hans Kasper Wigh; Bowen, Sean; Laustsen, Christoffer

    , the magnetization achievable with hyperpolarized water is superior to other nuclei. Methods A 1 mL sample of 50% water and 50% glycerol with 30 mM TEMPO is polarized in a Spinlab (GE Healthcare) at 5 T, 0.9 K, 139.9 GHz for an hour. The sample is rapidly dissolved in 16 mL deoxygenized dissolution medium (DM......Introduction Magnetic Resonance Angiography (MRA) is an important tool in diagnostics of medical conditions such as emboli, stenosis and aneurysms. Sub-millimetre resolution can be obtained with proton imaging, and further optimization can be obtained with Gd-based blood pool agents1. However......, the acquisition time is several minutes, and conventional MRA methods thus fail to image within a single respiration or heartbeat and therefore suffers from motion artefacts. We demonstrate that hyperpolarized (HP) water can be used as an imaging agent to provide subsecond angiographies in pigs. Previous work...

  15. Catheter Angiography

    Medline Plus

    Full Text Available ... resonance imaging (MRI) In catheter angiography, a thin plastic tube, called a catheter , is inserted into an ... The catheter used in angiography is a long plastic tube about as thick as a strand of ...

  16. Abnormal pulmonary vein drainage in upper right lobe associated with double aortic arch : magnetic resonance angiography

    International Nuclear Information System (INIS)

    Busto, M.; Dolz, J.L.; Capdevilla, A.; Castanon, M.; Mulet, J.

    1997-01-01

    We present the magnetic resonance (MR) and magnetic resonance angiography (MRA) findings in a case of abnormal pulmonary vein drainage from upper right lobe to superior vena cava, associated with double aortic arch, in a six-month-old boy. (Author) 9 refs

  17. Contrast-enhanced magnetic resonance angiography of persistent fifth aortic arch in children

    International Nuclear Information System (INIS)

    Zhong, Yumin; Zhu, Ming; Sun, Aimin; Li, Yuhua; Jaffe, Richard B.; Gao, Wei

    2007-01-01

    Cine angiography and echocardiography have been utilized to diagnose congenital aortic arch anomalies. However, the visualization of great vessels by echocardiography is limited, while cine angiography requires cardiac catheterization with ionizing radiation. Contrast-enhanced magnetic resonance angiography (MRA) is a noninvasive modality suitable for visualization of congenital aortic arch anomalies. To evaluate the utility of contrast-enhanced MRA in the diagnosis of persistent fifth aortic arch, a rare congenital aortic arch anomaly, and to compare the diagnostic accuracy of MRA with that of echocardiography and cine angiography. In four pediatric patients, contrast-enhanced MRA studies were performed for diagnosing persistent fifth aortic arch. The findings of MRA were compared with echocardiographic findings and confirmed by cine angiography and operation. Transthoracic surface echocardiography noted an aberrant vessel arising from the ascending aorta in two of four patients; the etiology of this vessel was uncertain. In the other two patients a diagnosis of coarctation was made. Of the four patients, only one was diagnosed with interruption of the aortic arch. Contrast-enhanced MRA clarified uncertain echocardiographic findings, enabling the correct diagnosis of persistent fifth aortic arch with fourth aortic arch interruption in all four patients. Contrast-enhanced MRA is a safe, accurate, and fast imaging technique for the evaluation of persistent fifth aortic arch and may obviate the need for conventional cine angiography. Cardiac catheterization may be reserved for some types of complicated congenital heart disease and for obtaining hemodynamic information. (orig.)

  18. Magnetic resonance angiography in suspected cerebral vasculitis

    International Nuclear Information System (INIS)

    Demaerel, Philippe; De Ruyter, Nele; Wilms, Guido; Maes, Frederik; Velghe, Beatrijs

    2004-01-01

    The purpose of this study was to determine the technical capacity and diagnostic accuracy of 3D time-of-flight magnetic resonance angiography (MRA) in suspected cerebral vasculitis in a retrospective analysis of MRA and digital subtraction angiography (DSA) in 14 young patients with clinical and/or radiological suspicion of cerebral vasculitis. A total of nine arteries were evaluated in each patient. Consensus review of DSA by three observers was the reference standard. The sensitivity for detecting a stenosis varied from 62 to 79% for MRA and from 76 to 94% for DSA, depending on the observer. The specificity for detecting a stenosis varied from 83 to 87% for MRA and from 83 to 97% for DSA. Using the criterion ''more than two stenoses in at least two separate vascular distributions'' to consider the examination as being true positive, the false-positive rates for MRA and DSA were comparable. MRA plays a role as the first angiographical examination in the diagnostic work-up of suspected cerebral vasculitis. When more than two stenoses in at least two separate vascular distributions are depicted on MRA, DSA is not expected to add a significant diagnostic contribution in a patient with suspected cerebral vasculitis. DSA remains necessary when MRA is normal or when less than three stenoses are seen. (orig.)

  19. Magnetic resonance angiography in suspected cerebral vasculitis

    Energy Technology Data Exchange (ETDEWEB)

    Demaerel, Philippe; De Ruyter, Nele; Wilms, Guido [Department of Radiology, Universitair Ziekenhuis, KU Leuven, 3000, Leuven (Belgium); Maes, Frederik [Department of Medical Imaging Computing, Universitair Ziekenhuis, KU Leuven, 3000, Leuven (Belgium); Velghe, Beatrijs [Department of Radiology, Ziekenhuis Oost-Limburg, Schiepse Bos 6, 3600, Genk (Belgium)

    2004-06-01

    The purpose of this study was to determine the technical capacity and diagnostic accuracy of 3D time-of-flight magnetic resonance angiography (MRA) in suspected cerebral vasculitis in a retrospective analysis of MRA and digital subtraction angiography (DSA) in 14 young patients with clinical and/or radiological suspicion of cerebral vasculitis. A total of nine arteries were evaluated in each patient. Consensus review of DSA by three observers was the reference standard. The sensitivity for detecting a stenosis varied from 62 to 79% for MRA and from 76 to 94% for DSA, depending on the observer. The specificity for detecting a stenosis varied from 83 to 87% for MRA and from 83 to 97% for DSA. Using the criterion ''more than two stenoses in at least two separate vascular distributions'' to consider the examination as being true positive, the false-positive rates for MRA and DSA were comparable. MRA plays a role as the first angiographical examination in the diagnostic work-up of suspected cerebral vasculitis. When more than two stenoses in at least two separate vascular distributions are depicted on MRA, DSA is not expected to add a significant diagnostic contribution in a patient with suspected cerebral vasculitis. DSA remains necessary when MRA is normal or when less than three stenoses are seen. (orig.)

  20. Atherosclerosis of the carotid artery: evaluation by magnetic resonance angiography.

    Science.gov (United States)

    Wildy, K S; Yuan, C; Tsuruda, J S; Ferguson, M S; Wen, N; Subramaniam, D S; Strandness, D E

    1996-01-01

    Carotid artery atherosclerotic plaques (APs) can lead to brain ischemia, an event shown to correlate with both the degree of stenosis and the composition of the AP. Currently, accurate estimates of stenosis can be obtained by either x-ray angiography or three-dimensional time-of-flight (TOF) magnetic resonance angiography (MRA). Our purpose was to determine whether three-dimensional TOF MRA images could also provide information on plaque location, morphology, and composition. Seven pre-endarterectomy patients underwent three-dimensional TOF MRA. After endarterectomy, plaque histology was evaluated. Three-dimensional TOF MRA images contained sufficient soft tissue contrast to differentiate the plaques from the surrounding tissues in all cases. Estimation of plaque morphology had 80% correlation with histology. Finally, intraplaque hemorrhage and calcification were deplicted as regions of moderately high and very low intensity, respectively. These preliminary results suggest that three-dimensional TOF MRA may be useful in studying the development and progression of carotid atherosclerosis.

  1. Diagnostic yield and accuracy of CT angiography, MR angiography, and digital subtraction angiography for detection of macrovascular causes of intracerebral haemorrhage: Prospective, multicentre cohort study

    NARCIS (Netherlands)

    C.J.J. Van Asch (Charlotte J.J.); B.K. Velthuis (Birgitta K.); G.J.E. Rinkel (Gabriël J.E.); A. Algra (Ale); G.A.P. de Kort (G. A P); T.D. Witkamp (Theo); J.C.M. De Ridder (Johanna C.M.); K.M. Van Nieuwenhuizen (Koen M.); F.-E. De Leeuw (Frank-Erik); W.J. Schonewille (Wouter); P.L.M. de Kort (Paul); D.W.J. Dippel (Diederik); T.W.M. Raaymakers (Theodora W.M.); J. Hofmeijer; M.J.H. Wermer (Marieke); H. Kerkhoff (Henk); K. Jellema (Korné); I.M. Bronner (Irene M.); M.J.M. Remmers (Michel ); H.P. Bienfait (Henri); R.J.G.M. Witjes (Ron J.G.M.); J.P. Greving (Jacoba); C.J.M. Klijn (Catharina J.M.); H.F. de Leeuw (Frank); H.B. Boogaarts; E.J. van Dijk (Ewoud); W.J. Schonewille; W.M.J. Pellikaan; C. Puppels-De Waard; P.L.M. De Kort; J.P. Peluso; J. van Tuijl (Jordie); J. Hofmeijer; F.B.M. Joosten (Frank); D.W.J. Dippel (Diederik); L. Khajeh (Ladbon); T.W.M. Raaijmakers; M.J. Wermer; M.A.A. van Walderveen (Marianne); H. Kerkhoff; E. Zock; K. Jellema (Korné); G.J. Lycklama à Nijeholt (Geert); I.M. Bronner; M.J.M. Remmers; R.J.G.M. Witjes; H.P. Bienfait; K.E. Droogh-Greve; R. Donders (Rogier); V.I.H. Kwa; T.H.C.M.L. Schreuder (Tobien H. C. M. L.); C.L. Franke (Cees); J.S. Straver; C. Jansen; S.L.M. Bakker (Stef); C.C. Pleiter (C.); M.C. Visser; C.J.J. Van Asch; B.K. Velthuis (Birgitta); G.J.E. Rinkel (Gabriel); K.M. Van Nieuwenhuizen; C.J.M. Klijn (Catharina J.M.)

    2015-01-01

    textabstractStudy question What are the diagnostic yield and accuracy of early computed tomography (CT) angiography followed by magnetic resonance imaging/angiography (MRI/MRA) and digital subtraction angiography (DSA) in patients with non-traumatic intracerebral haemorrhage? Methods This

  2. Comparison of digital subtraction angiography with gadolinium-enhanced magnetic resonance angiography in the diagnosis of renal artery stenosis

    International Nuclear Information System (INIS)

    Thornton, J.; O'Callaghan, J.; Varghese, J.C.; Lee, M.J.; Walshe, J.; O'Brien, E.

    1999-01-01

    Renal artery stenosis (RAS) is a treatable cause of hypertension and renal failure for which no ideal screening technique is currently available. We evaluated the use of dynamic gadolinium-enhanced magnetic resonance angiography (MRA) for the diagnosis of RAS. Sixty-two patients with secondary hypertension were enrolled in the study. All patients had conventional renal angiography and gadolinium enhanced MRA. The sequence used was a 3D FMP SPGR sequence with the following parameters (TR: 26 ms, TE: 6.9 ms, flip angle 40 , field of view 36 x 36 cm, matrix 246 x 256, 1 excitation). Gadolinium 0.3 mmol/kg was administered and 60 1.5-mm-thick partitions were obtained over a duration of 3.5 min. The MRA images were then compared with conventional digital subtraction angiography (DSA) images. Conventional DSA demonstrated 138 renal arteries, whereas gadolinium-enhanced MRA demonstrated 129 (93 %). Twenty-one renal artery stenoses and four occluded arteries were seen at conventional DSA. Gadolinium-enhanced MRA had a sensitivity of 88 %, specificity of 98 %, accuracy of 96 %, positive predictive value of 92 % and negative predictive value of 97 % when compared with conventional DSA. Gadolinium-enhanced MRA is an accurate technique for identifying patients with RAS. It is less sensitive in picking up accessory renal arteries. (orig.)

  3. Contrast-enhanced magnetic resonance angiography: evaluation of renal arteries in living renal transplant donors

    International Nuclear Information System (INIS)

    Firat, Ali; Akin, Oguz; Muhtesem Agildere, Ahmet; Aytekin, Cuneyt; Haberal, Mehmet

    2004-01-01

    One of the most important steps before living-donor nephrectomy is assessment of renal vascular anatomy. The number, origins and lengths of the renal arteries and variations of renal veins must be determined in order to identify the kidney that is most suitable for transplantation. Digital subtraction angiography was long considered the standard procedure for this purpose, but this method has been replaced by non-invasive techniques. Contrast-enhanced magnetic resonance angiography is an accurate, safe and reliable method for imaging vasculature. This article reviews the technique and the clinical features of this method in the evaluation of living renal transplant donors

  4. Magnetic Resonance Imaging and Angiography for the Prerupture Diagnosis of Rudimentary Uterine Horn Pregnancy

    Energy Technology Data Exchange (ETDEWEB)

    Ozeren, S.; Caliskan, E.; Corakci, A.; Ozkan, S.; Demirci, A. [Kocaeli Univ., Faculty of Medicine, Kocaeli (Turkey). Dept. of Obstetrics and Gynecology

    2004-12-01

    Magnetic resonance (MR) imaging and MR angiography were used for the differential diagnosis and preoperative planning of a 17 weeks of age rudimentary horn pregnancy. A 26-year-old primigravida was referred to our hospital with a preliminary diagnosis of abdominal pregnancy. After an inconclusive ultrasound evaluation we were able to identify a rudimentary horn pregnancy, extent of the placental invasion, and the vascular supply via MR imaging and time of flight sequence MR angiography. The obtained data were also used for preoperative planning, which resulted in an uncomplicated, prerupture laparotomy for pregnancy termination and a healthy female.

  5. Contrast-enhanced magnetic resonance angiography: evaluation of renal arteries in living renal transplant donors

    Energy Technology Data Exchange (ETDEWEB)

    Firat, Ali; Akin, Oguz; Muhtesem Agildere, Ahmet; Aytekin, Cuneyt; Haberal, Mehmet

    2004-10-01

    One of the most important steps before living-donor nephrectomy is assessment of renal vascular anatomy. The number, origins and lengths of the renal arteries and variations of renal veins must be determined in order to identify the kidney that is most suitable for transplantation. Digital subtraction angiography was long considered the standard procedure for this purpose, but this method has been replaced by non-invasive techniques. Contrast-enhanced magnetic resonance angiography is an accurate, safe and reliable method for imaging vasculature. This article reviews the technique and the clinical features of this method in the evaluation of living renal transplant donors.

  6. The Role of Coronary Computed Tomography Angiography and Cardiac Magnetic Resonance in STEMI Patients with Normal Coronary Angiography

    Directory of Open Access Journals (Sweden)

    Beganu Elena

    2017-09-01

    Full Text Available Usually, the diagnosis of myocardial infarction based on patient symptoms, electrocardiogram (ECG changes, and cardiac enzymes, is not a challenge for cardiologists. The correlation between coronary anatomy and the ECG territories that present ischemic changes can help the clinician to estimate which coronary artery presents lesions upon performing a coronary angiogram. In certain situations, the diagnosis of myocardial infarction can be difficult due to the lack of correlations between the clinical and paraclinical examinations and the coronary angiogram. In some cases, patients with chest pain and ST-segment elevation on the ECG tracing present with a normal coronary angiography. In other cases, patients without important changes on the ECG can present critical lesions or even occlusions upon angiographic examination. The aim of this article is to highlight the role of noninvasive coronary magnetic resonance and multi-slice computed tomography in patients with ST-segment elevation myocardial infarction and normal coronary angiography.

  7. Metabolic syndrome predicts vascular changes in whole body magnetic resonance imaging in patients with long standing diabetes mellitus

    Directory of Open Access Journals (Sweden)

    Findeisen Hannes M

    2010-08-01

    Full Text Available Abstract Background Although diabetic patients have an increased rate of cardio-vascular events, there is considerable heterogeneity with respect to cardiovascular risk, requiring new approaches to individual cardiovascular risk factor assessment. In this study we used whole body-MR-angiography (WB-MRA to assess the degree of atherosclerosis in patients with long-standing diabetes and to determine the association between metabolic syndrome (MetS and atherosclerotic burden. Methods Long standing (≥10 years type 1 and type 2 diabetic patients (n = 59; 31 males; 63.3 ± 1.7 years were examined by WB-MRA. Based on the findings in each vessel, we developed an overall score representing the patient's vascular atherosclerotic burden (MRI-score. The score's association with components of the MetS was assessed. Results The median MRI-score was 1.18 [range: 1.00-2.41] and MetS was present in 58% of the cohort (type 2 diabetics: 73%; type 1 diabetics: 26%. Age (p = 0.0002, HDL-cholesterol (p = 0.016, hypertension (p = 0.0008, nephropathy (p = 0.0093, CHD (p = 0.001 and MetS (p = 0.0011 were significantly associated with the score. Adjusted for age and sex, the score was significantly (p = 0.02 higher in diabetics with MetS (1.450 [1.328-1.572] compared to those without MetS (1.108 [0.966-1.50]. The number of MetS components was associated with a linear increase in the MRI-score (increase in score: 0.09/MetS component; r2 = 0.24, p = 0.038. Finally, using an established risk algorithm, we found a significant association between MRI-score and 10-year risk for CHD, fatal CHD and stroke. Conclusion In this high-risk diabetic population, WB-MRA revealed large heterogeneity in the degree of systemic atherosclerosis. Presence and number of traits of the MetS are associated with the extent of atherosclerotic burden. These results support the perspective that diabetic patients are a heterogeneous population with increased but varying prevalence of atherosclerosis

  8. Metabolic syndrome predicts vascular changes in whole body magnetic resonance imaging in patients with long standing diabetes mellitus.

    Science.gov (United States)

    Findeisen, Hannes M; Weckbach, Sabine; Stark, Renée G; Reiser, Maximilian F; Schoenberg, Stefan O; Parhofer, Klaus G

    2010-08-30

    Although diabetic patients have an increased rate of cardio-vascular events, there is considerable heterogeneity with respect to cardiovascular risk, requiring new approaches to individual cardiovascular risk factor assessment. In this study we used whole body-MR-angiography (WB-MRA) to assess the degree of atherosclerosis in patients with long-standing diabetes and to determine the association between metabolic syndrome (MetS) and atherosclerotic burden. Long standing (> or = 10 years) type 1 and type 2 diabetic patients (n = 59; 31 males; 63.3 +/- 1.7 years) were examined by WB-MRA. Based on the findings in each vessel, we developed an overall score representing the patient's vascular atherosclerotic burden (MRI-score). The score's association with components of the MetS was assessed. The median MRI-score was 1.18 [range: 1.00-2.41] and MetS was present in 58% of the cohort (type 2 diabetics: 73%; type 1 diabetics: 26%). Age (p = 0.0002), HDL-cholesterol (p = 0.016), hypertension (p = 0.0008), nephropathy (p = 0.0093), CHD (p = 0.001) and MetS (p = 0.0011) were significantly associated with the score. Adjusted for age and sex, the score was significantly (p = 0.02) higher in diabetics with MetS (1.450 [1.328-1.572]) compared to those without MetS (1.108 [0.966-1.50]). The number of MetS components was associated with a linear increase in the MRI-score (increase in score: 0.09/MetS component; r2 = 0.24, p = 0.038). Finally, using an established risk algorithm, we found a significant association between MRI-score and 10-year risk for CHD, fatal CHD and stroke. In this high-risk diabetic population, WB-MRA revealed large heterogeneity in the degree of systemic atherosclerosis. Presence and number of traits of the MetS are associated with the extent of atherosclerotic burden. These results support the perspective that diabetic patients are a heterogeneous population with increased but varying prevalence of atherosclerosis and risk.

  9. Algorithms for the Analysis of 3D Magnetic Resonance Angiography Images

    International Nuclear Information System (INIS)

    Tizon, Xavier

    2004-01-01

    Atherosclerosis is a disease of the arterial wall, progressively impairing blood flow as it spreads throughout the body. The heart attacks and strokes that result of this condition cause more deaths than cancer in industrial countries. Angiography refers to the group of imaging techniques used through the diagnosis, treatment planning and follow-up of atherosclerosis. In recent years, Magnetic Resonance Angiography (MRA) has shown promising abilities to supplant conventional, invasive, X-ray-based angiography. In order to fully benefit from this modality, there is a need for more objective and reproducible methods. This thesis shows, in two applications, how computerized image analysis can help define and implement these methods. First, by using segmentation to improve visualization of blood-pool contrast enhanced (CE)-MRA, with an additional application in coronary Computerized Tomographic Angiography. We show that, using a limited amount of user interaction and an algorithmic framework borrowed from graph theory and fuzzy logic theory, we can simplify the display of complex 3D structures like vessels. Second, by proposing a methodology to analyze the geometry of arteries in whole-body CE-MRA. The vessel centreline is extracted, and geometrical properties of this 3D curve are measured, to improve interpretation of the angiograms. It represents a more global approach than the conventional evaluation of atherosclerosis, as a first step towards screening for vascular diseases. We have developed the methods presented in this thesis with clinical practice in mind. However, they have the potential to be useful to other applications of computerized image analysis

  10. Recent advances in contrast-enhanced magnetic resonance angiography

    International Nuclear Information System (INIS)

    Meaney, J.F.M.; Goyen, M.

    2007-01-01

    Magnetic resonance angiography (MRA) provides a means of visualizing vascular structures noninvasively and is increasingly replacing conventional X-ray angiography in routine use. Contrast-enhanced MRA (CE-MRA), in which gadolinium contrast agents are used to shorten the T1 relaxation, offers increased resolution and higher signal-to-noise ratio compared with earlier flow-dependent [time-of-flight (TOF) or phase-contrast (PC)] techniques. Currently available contrast agents differ in their ability to lower T1 values, and hence the choice of contrast agent is an important consideration in the successful use of CE-MRA. Gadofosveset trisodium (Vasovist, Bayer Schering Pharma AG, Berlin, Germany) is the first of a new class of intravascular contrast agents. This agent is extensively (approximately 85%) and reversibly bound to human serum albumin and is retained within the vasculature thus allowing steady-state imaging to be perform-ed. An additional benefit is that gado0fosveset offers higher relaxivity compared with other contrast agents, thus giving a lower blood T1 values which also makes it ideal for first-pass imaging. Clinical trials have consistently shown that gadofosveset enhanced MRA is more sensitive, specific and accurate than time-of-flight MRA, gives fewer uninterpretable scans and affords greater diagnostic confidence. Intravascular contrast agents such as gadofosveset, therefore, offer the potential for improved vascular imaging. (orig.)

  11. MR angiography with Vasovist

    Energy Technology Data Exchange (ETDEWEB)

    Goyen, Mathias [University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20251 Hamburg (Germany)], E-mail: goyen@uke.uni-hamburg.de

    2007-12-15

    Vasovist (Gadofosveset) is the first intravascular contrast agent approved for use with magnetic resonance angiography in the European Union. This blood pool contrast agent reversibly binds to albumin providing extended intravascular enhancement compared to existing extracellular magnetic resonance contrast agents. Prior to approval, Vasovist underwent extensive clinical and pre-clinical testing to evaluate the safety and efficacy of the drug. The clinical trials program included blinded, placebo-controlled dose ranging, efficacy in a variety of vascular beds (aorto-iliac, renal, pedal), examination of potential drug interaction with warfarin, and comparison with X-ray angiography. The clinical trials show that Vasovist-enhanced MR angiography is safe and well tolerated in patients with vascular disease, effective for the detection of vascular stenosis and aneurysms, significantly more accurate (both more sensitive and specific) than non-contrast MR angiography for the diagnosis of vascular stenoses, and similar to conventional angiography for the overall characterization of vascular disease, without the need for catheterization. This review article highlights the product characteristics of Vasovist, gives an overview of the clinical development program and discusses selected clinical applications.

  12. MR angiography with Vasovist

    International Nuclear Information System (INIS)

    Goyen, Mathias

    2007-01-01

    Vasovist (Gadofosveset) is the first intravascular contrast agent approved for use with magnetic resonance angiography in the European Union. This blood pool contrast agent reversibly binds to albumin providing extended intravascular enhancement compared to existing extracellular magnetic resonance contrast agents. Prior to approval, Vasovist underwent extensive clinical and pre-clinical testing to evaluate the safety and efficacy of the drug. The clinical trials program included blinded, placebo-controlled dose ranging, efficacy in a variety of vascular beds (aorto-iliac, renal, pedal), examination of potential drug interaction with warfarin, and comparison with X-ray angiography. The clinical trials show that Vasovist-enhanced MR angiography is safe and well tolerated in patients with vascular disease, effective for the detection of vascular stenosis and aneurysms, significantly more accurate (both more sensitive and specific) than non-contrast MR angiography for the diagnosis of vascular stenoses, and similar to conventional angiography for the overall characterization of vascular disease, without the need for catheterization. This review article highlights the product characteristics of Vasovist, gives an overview of the clinical development program and discusses selected clinical applications

  13. Vasovist-enhanced MR angiography

    International Nuclear Information System (INIS)

    Goyen, M.; Shamsi, K.; Schoenberg, S.O.

    2006-01-01

    Vasovist (MS-325) is the first intravascular contrast agent approved for use with magnetic resonance angiography in the European Union. Vasovist reversibly binds to albumin, providing extended intravascular enhancement compared to existing extracellular magnetic resonance contrast agents. Prior to approval, Vasovist underwent extensive testing to evaluate the safety and efficacy of the drug; the clinical trials program included blinded, placebo-controlled dose ranging, efficacy in a variety of vascular beds (AIOD, renal, pedal), examination of potential drug interaction with warfarin and comparison with XRA. The clinical trials show that Vasovist-enhanced MR angiography is safe and well-tolerated in patients with vascular disease, effective for the detection of vascular stenosis and aneurysms, significantly more accurate (both more sensitive and specific) than non-contrast MR angiography for the diagnosis of vascular stenoses, and similar to conventional angiography for the overall characterization of vascular disease, without the need for catheterization. (orig.)

  14. Vasovist-enhanced MR angiography

    Energy Technology Data Exchange (ETDEWEB)

    Goyen, M. [Univ. Medical Center, Hamburg-Eppendorf, Hamburg (Germany); Shamsi, K. [Berlex Lab., Inc., Montville, NJ (United States); Schoenberg, S.O. [Dept. of Clinical Radiology, Univ. Hospitals Grosshadern, Munich (Germany)

    2006-02-15

    Vasovist (MS-325) is the first intravascular contrast agent approved for use with magnetic resonance angiography in the European Union. Vasovist reversibly binds to albumin, providing extended intravascular enhancement compared to existing extracellular magnetic resonance contrast agents. Prior to approval, Vasovist underwent extensive testing to evaluate the safety and efficacy of the drug; the clinical trials program included blinded, placebo-controlled dose ranging, efficacy in a variety of vascular beds (AIOD, renal, pedal), examination of potential drug interaction with warfarin and comparison with XRA. The clinical trials show that Vasovist-enhanced MR angiography is safe and well-tolerated in patients with vascular disease, effective for the detection of vascular stenosis and aneurysms, significantly more accurate (both more sensitive and specific) than non-contrast MR angiography for the diagnosis of vascular stenoses, and similar to conventional angiography for the overall characterization of vascular disease, without the need for catheterization. (orig.)

  15. Magnetic resonance angiography compared to intra-arterial digital subtraction angiography in patients with subarachnoid haemorrhage

    International Nuclear Information System (INIS)

    Gouliamos, A.; Gotsis, E.; Vlahos, L.; Samara, C.; Kapsalaki, E.; Rologis, D.; Kapsalakis, Z.; Papavasiliou, C.

    1992-01-01

    In order to evaluate the sensitivity and specificity of magnetic resonance angiography (MRA) in spontaneous subarachnoid haemorrhage, 14 patients with recent haemorrhage verified by CT or lumbar puncture were investigated with both selective intra-arterial digital subtraction angiography (IA-DSA) and MRA by two independent teams, each having the same preangiographic information. The results were compared with each other and whenever possible (all positive cases except one) with those of surgical intervention. Seven patients were identified by MRA and IA-DSA as having a single aneurysm on the circle of Willis, 1 an aneurysm of the posterior inferior cerebellar artery 1 an aneurysm of the internal carotid artery (siphon) and 2 patients with two aneurysms on the circle of Willis. MRA and IA-DSA both failed to demonstrate aneurysms in 2 cases. Three patients had negative results on both methods and no surgical intervention was attempted. The aneurysms ranged from 0.3 to 1.5 cm in size. In most cases there was agreement between MRA and DSA, leading us to believe that, if the proper protocols are followed, MRA is a powerful alternative to other established methods in the detection of intracranial aneurysms. At this stage it will not replace IA-DSA prior to surgery, but the ability to obtain various projections using 3D MRA may improve surgical planning. (orig.)

  16. Magnetic resonance angiography compared to intra-arterial digital subtraction angiography in patients with subarachnoid haemorrhage

    Energy Technology Data Exchange (ETDEWEB)

    Gouliamos, A. (Dept. of Radiology, Athens Univ. (Greece)); Gotsis, E. (Diagnostic and Research Inst. Encephalos, Athens (Greece)); Vlahos, L. (Dept. of Radiology, Athens Univ. (Greece)); Samara, C. (Dept. of Radiology, Athens Univ. (Greece)); Kapsalaki, E. (Diagnostic and Research Inst. Encephalos, Athens (Greece)); Rologis, D. (Dept. of Neurosurgery, Athens General Hospital (Greece)); Kapsalakis, Z. (Diagnostic and Research Inst. Encephalos, Athens (Greece)); Papavasiliou, C. (Dept. of Radiology, Athens Univ. (Greece))

    1992-12-01

    In order to evaluate the sensitivity and specificity of magnetic resonance angiography (MRA) in spontaneous subarachnoid haemorrhage, 14 patients with recent haemorrhage verified by CT or lumbar puncture were investigated with both selective intra-arterial digital subtraction angiography (IA-DSA) and MRA by two independent teams, each having the same preangiographic information. The results were compared with each other and whenever possible (all positive cases except one) with those of surgical intervention. Seven patients were identified by MRA and IA-DSA as having a single aneurysm on the circle of Willis, 1 an aneurysm of the posterior inferior cerebellar artery 1 an aneurysm of the internal carotid artery (siphon) and 2 patients with two aneurysms on the circle of Willis. MRA and IA-DSA both failed to demonstrate aneurysms in 2 cases. Three patients had negative results on both methods and no surgical intervention was attempted. The aneurysms ranged from 0.3 to 1.5 cm in size. In most cases there was agreement between MRA and DSA, leading us to believe that, if the proper protocols are followed, MRA is a powerful alternative to other established methods in the detection of intracranial aneurysms. At this stage it will not replace IA-DSA prior to surgery, but the ability to obtain various projections using 3D MRA may improve surgical planning. (orig.)

  17. Gas enhanced magnetic resonance angiography of the cerebrum using carbon dioxide and oxygen - preliminary results

    DEFF Research Database (Denmark)

    Pedersen, Mads Møller; Hansen, Kristoffer Lindskov; Ohlhues, Anders

    Purpose/introduction Standard imaging of the cerebral arteries is performed using intravenous contrast in CT angiography and x-ray angiography. Magnetic resonance angiography (MRA) of the cerebral arteries using intravenous contrast media does not perform well. Contrast in the venous bed...... and Methods Two healthy volunteers were scanned during inhalation of three different gas mixtures: Gas I (air), Gas II (5% CO2, 21 % O2, 74 % N2), Gas III (5% CO2, 95% O2). For each gas mixture a time of flight (TOF) series on the cerebral arteries was performed. Following each TOF series an ECG-gated phase...... contrast sequence was performed to calculate volume flow in the common carotid arteries. MRA data was acquired with a 1.5 T Siemens VISION MR-system (SIEMENS Medical Systems, Germany) using a standard circularly polarized head coil. Reconstructed images of TOF series and volume flow measurements were...

  18. DIAGNOSTIC ACCURACY OF MAGNETIC RESONANCE ANGIOGRAPHY FOR UNRUPTURED CEREBRAL ANEURYSMS IN CORRELATION WITH DIGITAL SUBTRACTION ANGIOGRAPHY

    Directory of Open Access Journals (Sweden)

    Aleksandra Aracki-Trenkić

    2015-09-01

    Full Text Available Intracranial aneurysm is a focal, abnormal dilation of an artery of the brain. Magnetic resonance angiography (MRA is a non-invasive technique for vascular imaging and is thus widely used for screening for intracranial vascular lesions. The aim of the study was to show the diagnostic accuracy of 3D Time-of-Flight (3D TOF MRA in the detection of unruptured cerebral aneurysms with the use of digital subtraction angiography (DSA as the gold standard. A total of 2.612 consecutive patients underwent 3DTOF MRA. It showed unruptured aneurysms in 94 (3.6% patients. They included 68 women and 26 men ranging in age from 29 to 76 years (mean, 52.5 years. Twenty-six of them, 20 women and 6 men, underwent DSA. The Mann-Whitney U test was used for the correlation of size. Fisher’s test was used for the correlation of location. The statistical level of significance was set at p0.05 of aneurysms between TOF MRA and DSA. MRA is an accurate and non-invasive method for diagnosis of unruptured intracranial aneurysms. The results of study show the compatibility of MRA findings, the location and the size of an aneurysm in comparison with the “gold standard” – cerebral DSA.

  19. Magnetic resonance angiography of the extracranial carotid and vertebral arteries

    International Nuclear Information System (INIS)

    Akimura, Tatsuo; Saito, Kenichi; Nakayama, Hisato; Kashiwagi, Shiro; Kato, Shoichi; Ito, Haruhide.

    1994-01-01

    To evaluate the contribution of magnetic resonance angiography (MRA) in the screening study of the extracranial carotid and vertebral arteries using the conventional head and neck coils, 500 consecutive MRAs of the cervical vessels were performed using 1.5 tesla magnetic resonance unit with circularly polarized head coil. The 5 cm-thick imaging plane was placed in coronal fashion including both carotid and vertebral arteries. The imaging sequence was three-dimensional (3D) fast imaging with steady precession (FISP). In 10 patients with failed head coil examination, 10 patients with possible carotid and vertebral diseases and 10 volunteers, the extracranial carotid and vertebral arteries were examined with the Helmholtz neck coil. Both 3D- and 2D-FISP were performed in each case. The imaging plane was placed in oblique sagittal fashion. In 458 out of 500 cases (91.6%), the extracranial carotid and vertebral arteries were successfully depicted using head coil. In 20 patients with high shoulders, the carotid bifurcations were out of range of the head coil. In these cases, carotid bifurcations and the origins of the carotid and vertebral arteries were successfully revealed using a neck coil. To evaluate the stenotic lesions and tortuous vessels, 2D-FISP sequence seemed to be more suitable than 3D-FISP. Compared with conventional angiography, MRA caused overestimation of the degree of stenotic lesions. For screening examination of the extracranial carotid and vertebral arteries, most cases can be evaluated only with the conventional head coil. If depiction of the carotid bifurcation fails and the examination of carotids or vertebrals down to the aortic arch is needed, neck coil examination is required. (author)

  20. Complications after liver transplantation: evaluation with magnetic resonance imaging, magnetic resonance cholangiography, and 3-dimensional contrast-enhanced magnetic resonance angiography in a single session

    International Nuclear Information System (INIS)

    Boraschi, P.; Donati, F.; Gigoni, R.; Salemi, S.; Urbani, L.; Filipponi, F.; Falaschi, F.; Bartolozzi, C.

    2008-01-01

    To evaluate a comprehensive magnetic resonance imaging (MRI) protocol as noninvasive diagnostic modality for simultaneous detection of parenchymal, biliary, and vascular complications after liver transplantation. Fifty-two liver transplant recipients suspected to have parenchymal, biliary, and (or) vascular complications underwent our MRI protocol at 1.5T unit using a phased array coil. After preliminary acquisition of axial T 1 w and T 2 w sequences, magnetic resonance cholangiography (MRC) was performed through a breath-hold, thin- and thick-slab, single-shot T 2 w sequence in the coronal plane. Contrast-enhanced magnetic resonance angiography (CEMRA) was obtained using a 3-dimensional coronal spoiled gradient-echo sequence, which enabled acquisition of 32 partitions 2.0 mm thick. A fixed dose of 20 ml gadobenate dimeglumine was administered at 2 mL/s. A post-contrast T 1 w sequence was also performed. Two observers in conference reviewed source images and 3-dimensional reconstructions to determine the presence of parenchymal, biliary, and vascular complications. MRI findings were correlated with surgery, endoscopic retrograde cholangiography (ERC), biopsy, digital subtraction angiography (DSA), and imaging follow-up. MRI revealed abnormal findings in 32 out of 52 patients (61%), including biliary complications (anastomotic and nonanastomotic strictures, and lithiasis) in 31, vascular disease (hepatic artery stenosis and thrombosis) in 9, and evidence of hepatic abscess and hematoma in 2. ERC confirmed findings of MRC in 30 cases, but suggested disease underestimation in 2. DSA confirmed 7 magnetic resonance angiogram (MRA) findings, but suggested disease overestimation in 2. MRI combined with MRC and CEMRA can provide a comprehensive assessment of parenchymal, biliary, and vascular complications in most recipients of liver transplantation. (author)

  1. The efficiency of magnetic resonance angiography (MRA) in the diagnosis vertebrobasilar insufficiency (VBI)

    Energy Technology Data Exchange (ETDEWEB)

    Maeda, Hiroyuki; Ura, Masaharu; Ganaha, Akira; Yasuda, Shinobu; Noda, Yutaka [Ryukyus Univ., Nishihara, Okinawa (Japan). Faculty of Medicine

    2000-09-01

    Vertebrobasilar insufficiency (VBI) is found in many cases of vertigo in patients who visit otolaryngology clinics. But its symptoms tend to be transitory, and since objective findings cannot be obtained at the first examination it is difficult to diagnose. As a result, it is tentatively diagnosed based only on the past history or the outcome of an equilibrium test. It is useful to diagnose circulation insufficiency, the stenotic position or the degree of the vessels based on the angiography findings. However, an operation is dangerous and overly invasive and therefore surgery is often not performed in many cases. We performed magnetic resonance angiography (MRA) and found it to be easy to perform, safe, it required a short examination time and was not invasive. A total of 12 cases suspected to have VBI based on the findings of an equilibrium test, MRA was performed. We could identify the stenotic or obstructive position of the vessels in the vertebrobasilar system in six of the cases. In conclusion, MRA was found to have many advantages over angiography and thus was considered to be useful in making a definite diagnosis of VBI. (author)

  2. The efficiency of magnetic resonance angiography (MRA) in the diagnosis vertebrobasilar insufficiency (VBI)

    International Nuclear Information System (INIS)

    Maeda, Hiroyuki; Ura, Masaharu; Ganaha, Akira; Yasuda, Shinobu; Noda, Yutaka

    2000-01-01

    Vertebrobasilar insufficiency (VBI) is found in many cases of vertigo in patients who visit otolaryngology clinics. But its symptoms tend to be transitory, and since objective findings cannot be obtained at the first examination it is difficult to diagnose. As a result, it is tentatively diagnosed based only on the past history or the outcome of an equilibrium test. It is useful to diagnose circulation insufficiency, the stenotic position or the degree of the vessels based on the angiography findings. However, an operation is dangerous and overly invasive and therefore surgery is often not performed in many cases. We performed magnetic resonance angiography (MRA) and found it to be easy to perform, safe, it required a short examination time and was not invasive. A total of 12 cases suspected to have VBI based on the findings of an equilibrium test, MRA was performed. We could identify the stenotic or obstructive position of the vessels in the vertebrobasilar system in six of the cases. In conclusion, MRA was found to have many advantages over angiography and thus was considered to be useful in making a definite diagnosis of VBI. (author)

  3. An investigation of cerebral magnetic resonance angiography, 4

    International Nuclear Information System (INIS)

    Takeda, Sadanori; Sadamoto, Kazuhiko; Ohue, Shiro; Todo, Hirooki; Sakaki, Saburo.

    1991-01-01

    We have been studying MR angiography using the 0.5 tesla system. Recently we developed three-dimensional MR angiography on the 0.5 tesla system using the gradient-echo technique. The purpose of this study is to evaluate the clinical ability of this newly developed 3-D MR angiography to detect intracranial vascular diseases in comparison with SE or 2-D MR angiography. Twenty-eight patients (15 cerebral aneurysms, 8 arteriovenous malformations, and 5 others) were examined. Three-dimensional MR angiography was performed with TRs of from 60 to 90 msec, TEs of from 16 to 22 msec, flip angls of from 15 to 45 degrees, and a 256x256x16 or 32 matrix. The imaging volumes ranged in thickness from 48 to 64 mm. In our study, a subtraction technique composed of rephased and dephased sequences was applied. As the result of utilizing 0.5 tesla 3-D MR angiography with optimal parameters, good visualization of main cerebral arteries such as second-order branches was obtained. Cerebral aneurysms, AVMs, and arterial occlusions were also well demonstrated, but some of the giant aneurysms were displayed insufficiently for the various flows to be determined. We concluded that 3-D MR angiography on the 0.5 tesla system has the ability to detect intracranial vascular lesions and should be the method for the screening and follow-up of intracranial vascular diseases. (author)

  4. Duplicate origin of the posterior communicating artery diagnosed by magnetic resonance angiography.

    Science.gov (United States)

    Uchino, Akira; Kamiya, Kouhei; Suzuki, Chihiro

    2013-10-01

    Extremely rarely, a posterior communicating artery (PCoA) of "duplicate origin" occurs when two branches of the PCoA arise separately from the supraclinoid segment of the internal carotid artery (ICA) and quickly fuse to form an arterial ring. Three such cases previously reported were described as "fenestration." We report the case of this rare variation diagnosed by magnetic resonance angiography and discuss the differentiation of PCoA of duplicate origin from PCoA fenestration, supraclinoid ICA fenestration, and hyperplastic anterior choroidal artery.

  5. Measurement precision and biological variation of cranial arteries using automated analysis of 3 T magnetic resonance angiography

    DEFF Research Database (Denmark)

    Amin, Faisal Mohammad; Lundholm, Elisabet; Hougaard, Anders

    2014-01-01

    BACKGROUND: Non-invasive magnetic resonance angiography (MRA) has facilitated repeated measurements of human cranial arteries in several headache and migraine studies. To ensure comparability across studies the same automated analysis software has been used, but the intra- and interobserver, day-...

  6. Whole-body magnetic resonance angiography with blood-pool agents

    International Nuclear Information System (INIS)

    Kramer, H.; Morana, G.

    2007-01-01

    Although often asymptomatic, peripheral arterial disease (PAD) is associated with significant morbidity in a large proportion of patients. Atherosclerosis is the underlying pathology in many instances, involving the whole arterial tree. Whole-body magnetic resonance angiography (MRA) permits rapid, non-invasive and accurate evaluation of the entire vascular system and can be used for both diagnostic purposes and monitoring of vascular involvement in diseases such as diabetes, Marfan's syndrome and Takayasu arteritis. MRA has been used successfully in the identification of high-grade stenosis in PAD, abnormalities of the ileocaval veins and carotid plaque imaging. Carotid disease is significantly correlated with severe coronary artery disease and renal artery atherosclerosis. Symptomatic lesions in one vascular bed are often related to additional asymptomatic atherosclerotic lesions in other vascular regions. MRA may be advantageous over computed tomographic angiography because it can be performed with contrast media virtually devoid of serious toxicity and without utilization of ionizing radiation. Display of the entire arterial vasculature can be achieved in < 90 s, with excellent sensitivity and specificity. Recent technological advances, such as parallel imaging and the implementation of dedicated matrix coils, have further increased image quality, and in combination with the blood-pool contrast agents, such as gadofosveset trisodium (Vasovist, Bayer Schering Pharma AG, Berlin, Germany), extended imaging time, higher spatial resolution and larger anatomical coverage can be achieved. (orig.)

  7. Whole-body magnetic resonance angiography with blood-pool agents

    Energy Technology Data Exchange (ETDEWEB)

    Kramer, H. [Inst. for Clinical Radiology, Univ. Hospital Munich, Munich (Germany); Morana, G. [Radiological Dept., Hospital Ca' Foncello, Treviso (Italy)

    2007-03-15

    Although often asymptomatic, peripheral arterial disease (PAD) is associated with significant morbidity in a large proportion of patients. Atherosclerosis is the underlying pathology in many instances, involving the whole arterial tree. Whole-body magnetic resonance angiography (MRA) permits rapid, non-invasive and accurate evaluation of the entire vascular system and can be used for both diagnostic purposes and monitoring of vascular involvement in diseases such as diabetes, Marfan's syndrome and Takayasu arteritis. MRA has been used successfully in the identification of high-grade stenosis in PAD, abnormalities of the ileocaval veins and carotid plaque imaging. Carotid disease is significantly correlated with severe coronary artery disease and renal artery atherosclerosis. Symptomatic lesions in one vascular bed are often related to additional asymptomatic atherosclerotic lesions in other vascular regions. MRA may be advantageous over computed tomographic angiography because it can be performed with contrast media virtually devoid of serious toxicity and without utilization of ionizing radiation. Display of the entire arterial vasculature can be achieved in < 90 s, with excellent sensitivity and specificity. Recent technological advances, such as parallel imaging and the implementation of dedicated matrix coils, have further increased image quality, and in combination with the blood-pool contrast agents, such as gadofosveset trisodium (Vasovist, Bayer Schering Pharma AG, Berlin, Germany), extended imaging time, higher spatial resolution and larger anatomical coverage can be achieved. (orig.)

  8. Evaluation of the patency of an extracranial-intracranial bypass using magnetic resonance angiography with selective presaturation of bypass vessels

    Energy Technology Data Exchange (ETDEWEB)

    Mabuchi, Shoji; Nakayama, Naoki; Isu, Toyohiko; Harata, Tatsuo; Nanbu, Toshikazu [Kushiro Rousai Hospital, Hokkaido (Japan)

    1994-06-01

    Three-dimensional time-of-flight magnetic resonance (MR) angiography using radiofrequency presaturation pulses was used to evaluate the patency of extracranial-intracranial (EC/IC) bypass in 11 patients. Presaturation causes signal loss in the vascular territory supplied by the presaturated EC/IC bypass graft. In all patients with a patent EC/IC bypass graft confirmed on conventional angiography, disappearance of the signal of the middle cerebral artery receiving blood flow from the bypass graft was clearly observed on MR angiograms with presaturation, indicating patency of the EC/IC bypass graft. MR angiography with presaturation pulses is a noninvasive and repeatable method for evaluation of the function of an EC/IC bypass graft. (author).

  9. Diagnostic role of magnetic resonance angiography in Swyer James syndrome: Case series of two cases

    Directory of Open Access Journals (Sweden)

    Parashari Umesh

    2010-01-01

    Full Text Available Swyer James syndrome is a rare syndrome which occurs due to viral illness in early childhood. The post infective obliterative bronchiolitis results in arrest of lung growth and alveolarization with reduced vascularity resulting in classical radiological features. We describe two cases of patients fulfilling all the criteria of the syndrome - 1 Unilateral hyperlucent small lung in chest radiograph with air trapping on expiration, small ipsilateral hila and pulmonary artery. 2 Diffuse decrease in attenuation of lung parenchyma with bronchiectasis and reduction in vascularity. 3 Unilateral pruned tree appearance on angiography (MRA. The clinical presentation was recurrent chest infection in a child and infrequent bouts of hemoptysis in a middle aged female. The study demonstrates the role of magnetic resonance angiography in diagnosing the condition.

  10. Artifacts in MR angiography of the intracranial vessels using the 3D TOF and 3D PC techniques

    International Nuclear Information System (INIS)

    Park, Dong Woo; Lee, Seung Ro; Hahm, Chang Kok; Kim, Yong Soo; Park, Choong Ki

    1997-01-01

    To classify artifacts and to assess their frequency in magnetic resonance angiography of intracranial vessels using three- dimensional time-of-flight and phase-contrast techniques. One hundred and eleven patients with suspected cerebrovascular disease were imaged on a 1.5T superconducting magnetic resonance machine employing three- dimensional time-of-flight and phase-contrast magnetic resonance angiographic techniques. We retrospectively reviewed the artifacts in three- dimensional time-of-flight and phase-contrast magnetic resonance angiography of the intracranial circulatory system, comparing them with routine spin-echo magnetic resonance images and magnetic resonance angiography source images, and partially with conventional angiography. Artifacts in magnetic resonance angiography were classified as flow-related, and flow-unrealted, by patient, hardware, magnetic resonance angiography acquisition and postprocessing techniques. Type and frequency of flow-related artifacts included saturation artifact (100%), dephasing artifact (100%), phase-encoding ghost artifact (97%), turbulence artifact (14%) and flow displacement artifact (5%) on three- dimensional time-of-flight and phase-contrast magnetic resonance angiography, and phase aliasing artifact (2%) on three-dimensional phase-contrast magnetic resonance angiography. Type and frequency of flow-unrelated artifacts included stair-step artifact (100%) by three- dimensional reconstruction process, magnetic susceptibility artifact by carotid canal (69%) and metal (4%), maximum intensity projection artifact (30%) by maximum intensity projection algorithm, and motion artifact by respiration (20%) and voluntary movement (8%); these were seen on both time-of-flight and phase-contrast magnetic resonance angiography. Paramagnetic substance artifact by fat and paranasal sinus mucosa (100%), hematoma (14%) and gadolinium (5%) were seen on time-of-flight magnetic resonance angiography. In three- dimensional time-of-flight and

  11. Parenchymal abnormalities in cerebral venous thrombosis: findings of magnetic resonance imaging and magnetic resonance angiography; Alteracoes parenquimatosas na trombose venosa cerebral: aspectos da ressonancia magnetica e da angiorressonancia

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Clecia Santos; Pellini, Marcos [Universidade Federal, Rio de Janeiro, RJ (Brazil). Faculdade de Medicina. Dept. de Radiologia]. E-mail: csferreira@superig.com.br; Boasquevisque, Edson [Universidade do Estado do Rio de Janeiro, (UERJ), RJ (Brazil). Faculdade de Medicina. Dept. de Patologia; Souza, Luis Alberto M. de [Hospital da Beneficencia Portuguesa do Rio de Janeiro, RJ (Brazil). Servico de Imagem. Setor de Ressonancia Magnetica

    2006-09-15

    Objective: to determine the frequency and localization of parenchymal abnormalities in cerebral venous thrombosis on magnetic resonance imaging and magnetic resonance angiography as well as their correlation with the territory and affected venous drainage. Materials and methods: retrospective analysis (1996 to 2004) of 21 patients (3 male and 18 female) age range between 3 and 82 years (mean 40 years, median 36 years) with clinical and radiological diagnosis of cerebral venous thrombosis on magnetic resonance imaging and magnetic resonance angiography in 2D PC, 3D PC and contrast-enhanced 3D TOF sequences. The statistical analysis was performed with the qui-square test. Four patients had follow-up exams and three patients underwent digital subtraction angiography. Results: main predisposing factors were: infection, use of oral contraceptives, hormone replacement therapy and collagenosis. Predominant symptoms included: focal deficit, headache, alteration of consciousness level and seizures. Most frequent parenchymal manifestations were: cortical/subcortical edema or infarct, venous congestion and collateral circulation, meningeal enhancement and thalamic and basal ganglia edema or infarct. Occlusion occurred mainly in superior sagittal, left transverse, left sigmoid and straight sinuses. Cavernous sinus and cortical veins thrombosis are uncommon events. Conclusion: cerebral venous thrombosis is an uncommon cause of stroke, with favorable prognosis because of its reversibility. Diagnosis is highly dependent on the radiologist capacity to recognize the presentations of this disease, principally in cases where the diagnosis is suggested by parenchymal abnormalities rather than necessarily by visualization of the thrombus itself. An accurate and rapid diagnosis allows an immediate treatment, reducing the morbidity and mortality rates. (author)

  12. Whole body MR imaging in diabetes

    International Nuclear Information System (INIS)

    Weckbach, Sabine; Schoenberg, Stefan O.

    2009-01-01

    Diabetes mellitus is a major cardiovascular risk factor and one of the major causes for morbidity and mortality worldwide. Diabetic complications have not only major impact on the quality of life of diabetic patients, but are also potentially life-threatening. Therefore prevention, diagnosis and therapy of these long-term complications are of high importance. However, diagnosis of the variety of complications from diabetes mellitus remains a diagnostic challenge and usually several diagnostic steps are necessary to diagnose or exclude these complications. In the last years whole body magnetic resonance imaging (WB-MRI) including whole body magnetic resonance angiography (WB-MRA) has been introduced for cardiovascular imaging and is now increasingly applied in clinical routine for the workup of patients with cardiovascular disease and for cardiovascular screening. The article summarizes rationales for WB-MRI in diabetes mellitus, technical concepts of disease specific cardiovascular WB-MRI in diabetes mellitus and discusses potential clinical consequences.

  13. High-resolution ex vivo magnetic resonance angiography: a feasibility study on biological and medical tissues

    Directory of Open Access Journals (Sweden)

    Boel Lene WT

    2010-03-01

    Full Text Available Abstract Background In biomedical sciences, ex vivo angiography is a practical mean to elucidate vascular structures three-dimensionally with simultaneous estimation of intravascular volume. The objectives of this study were to develop a magnetic resonance (MR method for ex vivo angiography and to compare the findings with computed tomography (CT. To demonstrate the usefulness of this method, examples are provided from four different tissues and species: the human placenta, a rice field eel, a porcine heart and a turtle. Results The optimal solution for ex vivo MR angiography (MRA was a compound containing gelatine (0.05 g/mL, the CT contrast agent barium sulphate (0.43 mol/L and the MR contrast agent gadoteric acid (2.5 mmol/L. It was possible to perform angiography on all specimens. We found that ex vivo MRA could only be performed on fresh tissue because formalin fixation makes the blood vessels permeable to the MR contrast agent. Conclusions Ex vivo MRA provides high-resolution images of fresh tissue and delineates fine structures that we were unable to visualise by CT. We found that MRA provided detailed information similar to or better than conventional CTA in its ability to visualize vessel configuration while avoiding interfering signals from adjacent bones. Interestingly, we found that vascular tissue becomes leaky when formalin-fixed, leading to increased permeability and extravascular leakage of MR contrast agent.

  14. Prominent porto-systemic collateral pathways in patients with portal hypertension: demonstration by gadolinium-enhanced magnetic resonance angiography; Vias colaterais porto-sistemicas exuberantes em portadores de hipertensao portal: demonstracao pela angiografia por ressonancia magnetica com gadolinio

    Energy Technology Data Exchange (ETDEWEB)

    Caldana, Rogerio Pedreschi; Bezerra, Alexandre Araujo Sergio; Cecin, Alexnadre Oliveira; Souza, Luis Ronan Marques Ferreira de; Goldman, Susan Menasce; D' Ippolito, Giuseppe; Szejnfeld, Jacob [Universidade Federal de Sao Paulo (UNIFESP/EPM), Sao Paulo, SP (Brazil). Dept. de Diagnostico por Imagem]. E-mail: rogercal@uol.com.br

    2003-03-01

    To demonstrate the usefulness of gadolinium-enhanced magnetic resonance angiography in the evaluation of prominent porto-systemic collateral pathways. We reviewed the images from 40 patients with portal hypertension studied with gadolinium-enhanced magnetic resonance angiography and selected illustrative cases of prominent porto-systemic collateral pathways. The scans were performed using high field equipment (1.5 Tesla) and a 3 D volume technique. Image were obtained after intravenous injection of paramagnetic contrast media using a power injector. Magnetic resonance angiography demonstrated with precision the porto-systemic collateral pathways, particularly when investigating extensive territories or large vessels. The cases presented show the potential of this method in the investigation of patients with portal hypertension. Gadolinium-enhanced magnetic resonance angiography is a useful method for the evaluation of patients with portal hypertension and prominent collateral pathways. (author)

  15. Magnetic resonance imaging and angiography of the brain in embolic left atrial myxoma

    International Nuclear Information System (INIS)

    Marazuela, M.; Yebra, M.; Diego, J.; Durantez, A.; Garcia-Merino, A.; Brasa, J.M.

    1989-01-01

    A case of left atrial myxoma presenting exclusively with neurological symptoms, studies with magnetic resonance imaging (MRI) combined with cerebral angiography and computed tomography (CT) is reported. Typical angiographic findings suggested the diagnosis of myxoma. MRI showed multiple ischemic lesions disseminated throughout the entire brain, some of which had been clinically asymptomatic. Because of its sensitivity in identifying small cerebral infarcts, MRI should prove in the future to be a first-choice technique in the evaluation of the presence of an extent of cerebral involvement in embolic left atrial myxoma. (orig.)

  16. Magnetic resonance angiography and CT angiography of persistent primitive olfactory artery: Incidence and association rate with aneurysm in Korea

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Bo Ra; Yeo, Soo Hyun; Chang, Hyuk Won; Kim, Mi Jeong; Lee, Sung Moon; Kim, Ealmaan; Kim, Mi Kyung; Cho, Ho Chan; Kim, Hye Soon [Keimyung University College of Medicine, Daegu (Korea, Republic of)

    2012-06-15

    Japanese data indicates an incidence of persistent primitive olfactory artery (PPOA) of 0.14%. We studied the incidence of PPOA and associated cerebral vascular variation or anomalies in Korea. We retrospectively reviewed cranial magnetic resonance angiography (MRA) and computed tomography angiography (CTA) images of a total of 9841 patients of our institution. The diagnostic criterion of PPOA is extreme anterioinferior course of the proximal anterior cerebral artery, with a hairpin turn of the lateral projection. We found 29 cases (0.29%) with PPOA. The PPOA location was on the left in 19 cases, bilateral in 3 cases, and on the right in 7 cases. An aneurysm was found at the hairpin turn in 2 patients. There were aneurysms in other sites in 3 cases. There were hypoplasia of anterior cerebral artery in 3 cases, and fenestration of intracranial artery in 1 case. In Korean populations, the incidence of PPOA found in MRA and CTA was twice as high as that shown in the previous Japanese data. Within Korea, left side laterality is more common than right side or bilalterality. Aneurysmal dilatations at the hairpin turning point and aneurysms at other sites were found, and other vascular variations were observed in several cases.

  17. Blood Pool Contrast-enhanced Magnetic Resonance Angiography with Correlation to Digital Subtraction Angiography: A Pictorial Review

    Directory of Open Access Journals (Sweden)

    Martha-Grace Knuttinen

    2014-01-01

    Full Text Available Magnetic resonance angiography (MRA provides noninvasive visualization of the vascular supply of soft tissue masses and vascular pathology, without harmful radiation. This is important for planning an endovascular intervention, and helps to evaluate the efficiency and effectiveness of the treatment. MRA with conventional extracellular contrast agents relies on accurate contrast bolus timing, limiting the imaging window to first-pass arterial phase. The recently introduced blood pool contrast agent (BPCA, gadofosveset trisodium, reversibly binds to human serum albumin, resulting in increased T1 relaxivity and prolonged intravascular retention time, permitting both first-pass and steady-state phase high-resolution imaging. In our practice, high-quality MRA serves as a detailed "roadmap" for the needed endovascular intervention. Cases of aortoiliac occlusive disease, inferior vena cava thrombus, pelvic congestion syndrome, and lower extremity arteriovenous malformation are discussed in this article. MRA was acquired at 1.5 T with an 8-channel phased array coil after intravenous administration of gadofosveset (0.03 mmol/kg body weight, at the first-pass phase. In the steady-state, serial T1-weighted 3D spoiled gradient echo images were obtained with high resolution. All patients underwent digital subtraction angiography (DSA and endovascular treatment. MRA and DSA findings of vascular anatomy and pathology are discussed and correlated. BPCA-enhanced MRA provides high-quality first-pass and steady-state vascular imaging. This could increase the diagnostic accuracy and create a detailed map for pre-intervention planning. Understanding the pharmacokinetics of BPCA and being familiar with the indications and technique of MRA are important for diagnosis and endovascular intervention.

  18. Fluorine cardiovascular magnetic resonance angiography in vivo at 1.5 T with perfluorocarbon nanoparticle contrast agents.

    Science.gov (United States)

    Neubauer, Anne M; Caruthers, Shelton D; Hockett, Franklin D; Cyrus, Tillman; Robertson, J David; Allen, J Stacy; Williams, Todd D; Fuhrhop, Ralph W; Lanza, Gregory M; Wickline, Samuel A

    2007-01-01

    While the current gold standard for coronary imaging is X-ray angiography, evidence is accumulating that it may not be the most sensitive technique for detecting unstable plaque. Other imaging modalities, such as cardiovascular magnetic resonance (CMR), can be used for plaque characterization, but suffer from long scan and reconstruction times for determining regions of stenosis. We have developed an intravascular fluorinated contrast agent that can be used for angiography with cardiovascular magnetic resosnace at clinical field strengths (1.5 T). This liquid perfluorocarbon nanoparticle contains a high concentration of fluorine atoms that can be used to generate contrast on 19F MR images without any competing background signal from surrounding tissues. By using a perfluorocarbon with 20 equivalent fluorine molecules, custom-built RF coils, a modified clinical scanner, and an efficient steady-state free procession sequence, we demonstrate the use of this agent for angiography of small vessels in vitro, ex vivo, and in vivo. The surprisingly high signal generated with very short scan times and low doses of perfluorocarbon indicates that this technique may be useful in clinical settings when coupled with advanced imaging strategies.

  19. Contrast-enhanced magnetic resonance angiography in carotid artery disease: does automated image registration improve image quality?

    International Nuclear Information System (INIS)

    Menke, Jan; Larsen, Joerg

    2009-01-01

    Contrast-enhanced magnetic resonance angiography (MRA) is a noninvasive imaging alternative to digital subtraction angiography (DSA) for patients with carotid artery disease. In DSA, image quality can be improved by shifting the mask image if the patient has moved during angiography. This study investigated whether such image registration may also help to improve the image quality of carotid MRA. Data from 370 carotid MRA examinations of patients likely to have carotid artery disease were prospectively collected. The standard nonregistered MRAs were compared to automatically linear, affine and warp registered MRA by using three image quality parameters: the vessel detection probability (VDP) in maximum intensity projection (MIP) images, contrast-to-noise ratio (CNR) in MIP images, and contrast-to-noise ratio in three-dimensional image volumes. A body shift of less than 1 mm occurred in 96.2% of cases. Analysis of variance revealed no significant influence of image registration and body shift on image quality (p > 0.05). In conclusion, standard contrast-enhanced carotid MRA usually requires no image registration to improve image quality and is generally robust against any naturally occurring body shift. (orig.)

  20. Can carotid stenosis be operated without arteriography? Contribution of magnetic resonance and helical computerized tomography angiography

    International Nuclear Information System (INIS)

    Auffrau-Calvier, E.; Kersaint-Gilly, A. de; Desal, H.A.; Viarouge, M.P.; Havet, T.

    1996-01-01

    The aim of this work is to ascertain the role of the magnetic resonance angiography (MRA) and to compare it with the Doppler effect, the X-ray angiography and the new method of helical computerized tomography. Seventy one carotid bifurcations in 37 patients with suspected cerebral vascular events has been evaluated with the MRA and digitalized angiography, the reference method. The obtained data corroborate the good results proposed by other authors reporting in the literature and allow to propose this examination as a new means of investigating carotid bifurcations. Work with the helical computerized tomography appears to be promising too but there are few reported series. Therefore, there appears to be two interesting points: the reliability of distinguishing between very severe stenosis and occlusion, and the fine-tuned analysis of the plaque with detection of ulcerations. When a consistent approach is used to the evaluation of the carotid bifurcation, the Willis circle and the cerebral parenchyma, the MRA can complete the Doppler echo data and the preoperative arteriography can only be used in patients when the MRA and the Doppler echo results disagree. (authors)

  1. Magnetic resonance angiography

    International Nuclear Information System (INIS)

    Kauczor, H.U.; Gamroth, A.H.; Schad, L.R.; Semmler, W.; Kaick, G. van; Tuengerthal, S.J.; Hausmann, R.

    1992-01-01

    MR angiography (MRA) proved to be promising combined to MR-Imaging (MRI) in the assessment of intrathoracic masses. Sequential FLASH 2D-angiograms were acquired in breathhold technique using the following parameters: TR=30 ms, TE=10 ms, FA=30deg. Section thickness was 5 mm with 1 mm overlap between sequential sections. Individual conditions of the examination were achieved by an automatised control procedure. Targeted MIP-postprocessing resulted in 3D-reconstructions illustrating vascular anatomy and avoiding superimposition. Presentation should be done by cine-mode for better spatial impression. This method was evaluated in a prospective study of 21 patients with malignant pulmonary and mediastinal masses in addition to spin-echo imaging. The diagnostic contribution concerning the relationship between the mass and the vasculature like displacement, stenosis, and poststenotic perfusion defect were assessed. (orig.) [de

  2. Whole-body magnetic resonance angiography of patients using a standard clinical scanner

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, Tomas; Wikstroem, Johan; Eriksson, Mats-Ola; Lundberg, Anders; Ahlstroem, Haakan [Uppsala University Hospital, Department of Diagnostic Radiology, Uppsala (Sweden); Johansson, Lars [Uppsala University Hospital, Uppsala (Sweden); Ljungman, Christer [Uppsala University Hospital, Department of Vascular Surgery, Uppsala (Sweden); Hoogeven, Romhild [Philips Medical Systems, MR Clinical Science, Best (Netherlands)

    2006-01-01

    The purpose of this study was to evaluate the technique of whole-body magnetic resonance angiography (MRA) of patients with a standard clinical scanner. Thirty-three patients referred for stenoses, occlusions, aneurysms, assessment of patency of vascular grafts, vasculitis and vascular aplasia were examined in a 1.5-T scanner using its standard body coil. Three-dimensional sequences were acquired in four stations after administration of one intravenous injection of 40 ml conventional gadolinium contrast agent. Different vessel segments were evaluated as either diagnostic or nondiagnostic and regarding the presence of stenoses with more than 50% diameter reduction, occlusions or aneurysms. Of 923 vessel segments, 67 were not evaluable because of poor contrast filling (n=31), motion artefacts (n=20), venous overlap (n=12) and other reasons (n=4). Stenoses of more than 50%, occlusions or aneurysms were observed in 26 patients (129 segments). In nine patients additional unsuspected pathology was found. In 10 out of 14 patients (71/79 segments) there was conformity between MRA and digital subtraction angiography regarding the grade of stenosis. This study shows that whole-body MRA with a standard clinical scanner is feasible. Motion artefacts and the timing of the contrast agent through the different segments are still problems to be solved. (orig.)

  3. Chronic hepatosplenic schistosomiasis mansoni: magnetic resonance imaging and magnetic resonance angiography findings

    International Nuclear Information System (INIS)

    Bezerra, A.S.; D'Ippolito, G.; Caldana, R.P.; Cecin, A.O.; Ahmed, M.; Szejnfeld, J.

    2007-01-01

    Purpose: To evaluate the hepatosplenic manifestations and the portal venous system in patients with chronic infection by Schistosoma mansoni. Material and Methods: A cross-sectional observational study was performed in 28 patients with chronic hepatosplenic schistosomiasis submitted to magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) of the abdomen. Images were interpreted independently by two radiologists to determine the reproducibility of image interpretation and who evaluated the presence of morphological alterations in the liver and spleen, such as hepatosplenomegaly, hepatic fissure widening, periportal fibrosis, and the presence of siderotic nodules. Interobserver and intra-observer agreement were measured with the kappa and intraclass correlation tests. Evaluation of venous collateral pathways and portal and splenic veins was done in consensus by both examiners. Results: Observers identified enlargement of the left lobe (78.5-92.8%) and caudate-to-right-lobe ratio (78.5-92.8%), irregularity of hepatic contours (89.2-96.4%), fissure widening (89.2-100%), and splenic siderotic nodules (84.2%). Splenomegaly, heterogeneity of hepatic parenchyma, peripheral hepatic vessels, and periportal fibrosis were observed in 100% of patients. MRI findings presented almost perfect interobserver (kappa 0.65-1) and intra-observer (kappa = 0.73-1 for observer 1, and kappa = 0.65-1 for observer 2) agreement for the variables analyzed. MRA showed the presence of collateral pathways in the majority of patients (71.4%) along with widening of portal and splenic veins. Conclusion: Using MRI, hepatosplenic alterations in schistosomiasis are characterized by heterogeneity of hepatic parenchyma, presence of peripheral perihepatic vessels, periportal fibrosis, splenomegaly, siderotic nodules, and the presence of venous collateral pathways

  4. Renal artery and parenchymal changes after renal denervation: assessment by magnetic resonance angiography

    Energy Technology Data Exchange (ETDEWEB)

    Sanders, Margreet F.; Vink, Eva E.; Blankestijn, Peter J. [University Medical Center Utrecht, Department of Nephrology and Hypertension, PO Box 85500, Utrecht (Netherlands); Doormaal, Pieter Jan van; Habets, Jesse; Vonken, Evert-Jan; Leiner, Tim [University Medical Center Utrecht, Department of Radiology, Utrecht (Netherlands); Beeftink, Martine M.A.; Verloop, Willemien L.; Voskuil, Michiel [University Medical Center Utrecht, Department of Cardiology, Utrecht (Netherlands); Bots, Michiel L. [University Medical Center Utrecht, Julius Center for Health Sciences and Primary Care, Utrecht (Netherlands); Fadl Elmula, Fadl Elmula M. [Oslo University Hospital, Department of Internal Medicine and Department of Cardiology, Ullevaal, Oslo (Norway); Hammer, Frank [Cliniques Universitaires Saint-Luc, Universite Catholique de Louvain, Department of Radiology, Brussels (Belgium); Hoffmann, Pavel [Oslo University Hospital, Section for Interventional Cardiology, Department of Cardiology, Ullevaal, Oslo (Norway); Jacobs, Lotte; Staessen, Jan A. [University of Leuven, Studies Coordinating Centre, Research Unit Hypertension and Cardiovascular Epidemiology, KU Leuven Department of Cardiovascular Sciences, Leuven (Belgium); Mark, Patrick B.; Taylor, Alison H. [University of Glasgow, Institute of Cardiovascular and Medical Sciences, Glasgow, Scotland (United Kingdom); Persu, Alexandre; Renkin, Jean [Universite Catholique de Louvain, Pole of Cardiovascular Research, Institut de Recherche Experimentale et Clinique, Brussels (Belgium); Cliniques Universitaires Saint-Luc, Universite Catholique de Louvain, Cardiology Department, Brussels (Belgium); Roditi, Giles [Glasgow Royal Infirmary, Department of Radiology, Glasgow (United Kingdom); Spiering, Wilko [University Medical Centre Utrecht, Department of Vascular Medicine, Utrecht (Netherlands); Collaboration: on behalf of the European Network COordinating research on Renal Denervation (ENCOReD) Consortium

    2017-09-15

    Relatively little is known about the incidence of long-term renal damage after renal denervation (RDN), a potential new treatment for hypertension. In this study the incidence of renal artery and parenchymal changes, assessed with contrast-enhanced magnetic resonance angiography (MRA) after RDN, is investigated. This study is an initiative of ENCOReD, a collaboration of hypertension expert centres. Patients in whom an MRA was performed before and after RDN were included. Scans were evaluated by two independent, blinded radiologists. Primary outcome was the change in renal artery morphology and parenchyma. MRAs from 96 patients were analysed. Before RDN, 41 renal anomalies were observed, of which 29 mostly mild renal artery stenoses. After a median time of 366 days post RDN, MRA showed a new stenosis (25-49% lumen reduction) in two patients and progression of pre-existing lumen reduction in a single patient. No other renal changes were observed and renal function remained stable. We observed new or progressed renal artery stenosis in three out of 96 patients, after a median time of 12 months post RDN (3.1%). Procedural angiographies showed that ablations were applied near the observed stenosis in only one of the three patients. (orig.)

  5. Conventional digital subtraction x-ray angiography versus magnetic resonance angiography in the evaluation of carotid disease: patient satisfaction and preferences

    International Nuclear Information System (INIS)

    U-King-Im, J.M.; Trivedi, R.; Cross, J.; Higgins, N.; Graves, M.; Kirkpatrick, P.; Antoun, N.; Gillard, J.H.

    2004-01-01

    AIM: To compare conventional digital subtraction x-ray angiography (DSA) and contrast-enhanced magnetic resonance angiography (MRA) of the carotid arteries in terms of patient satisfaction and preferences. METHODS: One hundred and sixty-seven patients with symptomatic carotid artery disease, who underwent both DSA and MRA, were prospectively recruited in this study. Patients' perceptions of each method were assessed by the use of a questionnaire after each procedure. Main outcome measures were anxiety, pain, satisfaction rate and patient preferences. RESULTS: DSA generated more anxiety and pain during the procedure, but the severity of these ill-effects was mild. Satisfaction rates for each method were similar. More patients were, however, willing to have a repeat MRA compared with DSA (67 versus 41%). The majority of patients (62%) preferred MRA over DSA (31%). The shorter MRA imaging time was found to be a significant factor in patients' acceptance of the technique. The main reasons cited by patients for their dislike of a particular procedure was noise and claustrophobia for MRA and invasiveness, pain and post-procedural bed rest for DSA. CONCLUSIONS: MRA is the method that is preferred by the majority of patients, although the actual disutility of DSA may be small. Assuming equal diagnostic accuracy, our data supports replacement of DSA by MRA for routine carotid imaging

  6. Conventional digital subtraction x-ray angiography versus magnetic resonance angiography in the evaluation of carotid disease: patient satisfaction and preferences

    Energy Technology Data Exchange (ETDEWEB)

    U-King-Im, J.M. E-mail: jhg21@cam.ac.uk; Trivedi, R.; Cross, J.; Higgins, N.; Graves, M.; Kirkpatrick, P.; Antoun, N.; Gillard, J.H

    2004-04-01

    AIM: To compare conventional digital subtraction x-ray angiography (DSA) and contrast-enhanced magnetic resonance angiography (MRA) of the carotid arteries in terms of patient satisfaction and preferences. METHODS: One hundred and sixty-seven patients with symptomatic carotid artery disease, who underwent both DSA and MRA, were prospectively recruited in this study. Patients' perceptions of each method were assessed by the use of a questionnaire after each procedure. Main outcome measures were anxiety, pain, satisfaction rate and patient preferences. RESULTS: DSA generated more anxiety and pain during the procedure, but the severity of these ill-effects was mild. Satisfaction rates for each method were similar. More patients were, however, willing to have a repeat MRA compared with DSA (67 versus 41%). The majority of patients (62%) preferred MRA over DSA (31%). The shorter MRA imaging time was found to be a significant factor in patients' acceptance of the technique. The main reasons cited by patients for their dislike of a particular procedure was noise and claustrophobia for MRA and invasiveness, pain and post-procedural bed rest for DSA. CONCLUSIONS: MRA is the method that is preferred by the majority of patients, although the actual disutility of DSA may be small. Assuming equal diagnostic accuracy, our data supports replacement of DSA by MRA for routine carotid imaging.

  7. Technical requirements, biophysical considerations and protocol optimization with magnetic resonance angiography using blood-pool agents

    International Nuclear Information System (INIS)

    Rohrer, M.; Geerts-Ossevoort, L.; Laub, G.

    2007-01-01

    In order to maximize the potential benefits of contrast-enhanced magnetic resonance angiography, careful attention must be paid to the choice of hardware, data acquisition and processing, and to the choice of contrast agent. Typically, contrast-enhanced magnetic resonance angiography uses parallel-imaging techniques, which shorten the acquisition time, enhance spatial resolution and reduce artefacts. The timing of data acquisition is crucial for maximal enhancement of the arteries: for optimal arterial depiction, the centre of k-space should be acquired at the time of peak concentration of contrast agent in the arterial bed being investigated, and a number of k-space acquisition techniques are available to achieve this. SENSE or GRAPPA techniques can be used to facilitate parallel-imaging reconstruction of either the image data or k-space data, respectively. Gadolinium contrast agents shorten the proton relaxation times (most importantly T1) of blood, thereby increasing the signal-to-noise ratio and enhancing differentiation between blood vessels and other tissues. The blood-pool (intravascular) contrast agent gadofosveset trisodium (Vasovist, Bayer Schering Pharma AG, Berlin, Germany) is reversibly protein-bound in human plasma. This results in a marked increase in relaxivity, and hence a strong T1 shortening effect compared with other gadolinium-based contrast agents. Furthermore, the blood retention time of gadofosveset trisodium is substantially prolonged compared with conventional contrast agents. As a result, gadofosveset trisodium permits both first-pass and steady-state imaging. (orig.)

  8. Diagnostic accuracy of computer tomography angiography and magnetic resonance angiography in the stenosis detection of autologuous hemodialysis access: a meta-analysis.

    Directory of Open Access Journals (Sweden)

    Bin Li

    Full Text Available PURPOSE: To compare the diagnostic performances of computer tomography angiography (CTA and magnetic resonance angiography (MRA for detection and assessment of stenosis in patients with autologuous hemodialysis access. MATERIALS AND METHODS: Search of PubMed, MEDLINE, EMBASE and Cochrane Library database from January 1984 to May 2013 for studies comparing CTA or MRA with DSA or surgery for autologuous hemodialysis access. Eligible studies were in English language, aimed to detect more than 50% stenosis or occlusion of autologuous vascular access in hemodialysis patients with CTA and MRA technology and provided sufficient data about diagnosis performance. Methodological quality was assessed by the Quality Assessment of Diagnostic Studies (QUADAS instrument. Sensitivities (SEN, specificities (SPE, positive likelihood ratio (PLR, negative likelihood values (NLR, diagnostic odds ratio (DOR and areas under the receiver operator characteristic curve (AUC were pooled statistically. Potential threshold effect, heterogeneity and publication bias was evaluated. The clinical utility of CTA and MRA in detection of stenosis was also investigated. RESULT: Sixteen eligible studies were included, with a total of 500 patients. Both CTA and MRA were accurate modality (sensitivity, 96.2% and 95.4%, respectively; specificity, 97.1 and 96.1%, respectively; DOR [diagnostic odds ratio], 393.69 and 211.47, respectively for hemodialysis vascular access. No significant difference was detected between the diagnostic performance of CTA (AUC, 0.988 and MRA (AUC, 0.982. Meta-regression analyses and subgroup analyses revealed no statistical difference. The Deek's funnel plots suggested a publication bias. CONCLUSION: Diagnostic performance of CTA and MRA for detecting stenosis of hemodialysis vascular access had no statistical difference. Both techniques may function as an alternative or an important complement to conventional digital subtraction angiography (DSA and may be

  9. Magnetic resonance angiography: infrequent anatomic variants

    International Nuclear Information System (INIS)

    Trejo, Mariano; Meli, Francisco; Lambre, Hector; Blessing, Ricardo; Gigy Traynor, Ignacio; Miguez, Victor

    2002-01-01

    We studied through RM angiography (3D TOF) with high magnetic field equipment (1.5 T) different infrequent intracerebral vascular anatomic variants. For their detection we emphasise the value of post-processed images obtained after conventional angiographic sequences. These post-processed images should be included in routine protocols for evaluation of the intracerebral vascular structures. (author)

  10. Unusual Congenital Aortic Anomaly with Rare Common Celiamesenteric Trunk Variation: MR Angiography and Digital Substraction Angiography Findings

    International Nuclear Information System (INIS)

    Tosun, Ozgur; Sanlidilek, Umman; Cetin, Huseyin; Ozdemir, Ozcan; Kurt, Aydin; Sakarya, Mehmet Emin; Tas, Ismet

    2007-01-01

    Magnetic resonance angiography and digital substraction angiography (DSA) findings in a case with a rare congenital thoracoabdominal aortic hypoplasia and common celiamesenteric trunk variation with occlusion of infrarenal abdominal aorta are described here. To our knowledge, this aortic anomaly has not been previously described in the English literature. DSA is the optimum imaging modality for determination of aortic hypoplasia, associated vascular malformations, collateral vessels, and direction of flow within vessels

  11. Your Radiologist Explains Magnetic Resonance Angiography (MRA)

    Medline Plus

    Full Text Available ... Angiography (MRA) Transcript Welcome to Radiology Info dot org Hello, I’m Dr. Elliot Fishman, a radiologist ... question you might have, visit Radiology Info dot org. Thank you for your time and for your ...

  12. Utility of time-resolved three-dimensional magnetic resonance digital subtraction angiography without contrast material for assessment of intracranial dural arterio-venous fistula

    International Nuclear Information System (INIS)

    Hori, Masaaki; Aoki, Shigeki; Nakanishi, Atsushi; Shimoji, Keigo; Kamagata, Koji; Houshito, Haruyoshi; Kuwatsuru, Ryohei; Oishi, Hidenori; Arai, Hajime

    2011-01-01

    Background: Intracranial dural arteriovenous fistula (DAVF) is an arteriovenous shunting disease of the dura. Magnetic resonance angiography (MRA) is expected to be a safer alternative method in evaluation of DAVF, compared with invasive intra-arterial digital subtraction angiography (IADSA). Purpose: To evaluate the diagnostic use of time-spatial labeling inversion pulse (Time-SLIP) three-dimensional (3D) magnetic resonance digital subtraction angiography (MRDSA) without contrast material in six patients with DAVF. Material and Methods: Images for 3D time-of-flight MRA, which has been a valuable tool for the diagnosis of DAVF but provide little or less hemodynamic information, and Time-SLIP 3D MRDSA, were acquired for each patient. The presence, side, and grade of the disease were evaluated according to IADSA. Results: In all patients, the presence and side of the DAVF were correctly identified by both 3D time-of-flight MRA and Time-SLIP 3D MRDSA. Cortical reflux present in a patient with a grade 2b DAVF was not detected by Time-SLIP 3D MRDSA, when compared with IADSA findings. Conclusion: Time-SLIP 3D MRDSA provides hemodynamic information without contrast material and is a useful complementary tool for diagnosis of DAVF

  13. Noncontrast magnetic resonance angiography of the hand: improved arterial conspicuity by multidirectional flow-sensitive dephasing magnetization preparation in 3D balanced steady-state free precession imaging.

    Science.gov (United States)

    Fan, Zhaoyang; Hodnett, Philip A; Davarpanah, Amir H; Scanlon, Timothy G; Sheehan, John J; Varga, John; Carr, James C; Li, Debiao

    2011-08-01

    : To develop a flow-sensitive dephasing (FSD) preparative scheme to facilitate multidirectional flow-signal suppression in 3-dimensional balanced steady-state free precession imaging and to validate the feasibility of the refined sequence for noncontrast magnetic resonance angiography (NC-MRA) of the hand. : A new FSD preparative scheme was developed that combines 2 conventional FSD modules. Studies using a flow phantom (gadolinium-doped water 15 cm/s) and the hands of 11 healthy volunteers (6 males and 5 females) were performed to compare the proposed FSD scheme with its conventional counterpart with respect to the signal suppression of multidirectional flow. In 9 of the 11 healthy subjects and 2 patients with suspected vasculitis and documented Raynaud phenomenon, respectively, 3-dimensional balanced steady-state free precession imaging coupled with the new FSD scheme was compared with spatial-resolution-matched (0.94 × 0.94 × 0.94 mm) contrast-enhanced magnetic resonance angiography (0.15 mmol/kg gadopentetate dimeglumine) in terms of overall image quality, venous contamination, motion degradation, and arterial conspicuity. : The proposed FSD scheme was able to suppress 2-dimensional flow signal in the flow phantom and hands and yielded significantly higher arterial conspicuity scores than the conventional scheme did on NC-MRA at the regions of common digitals and proper digitals. Compared with contrast-enhanced magnetic resonance angiography, the refined NC-MRA technique yielded comparable overall image quality and motion degradation, significantly less venous contamination, and significantly higher arterial conspicuity score at digital arteries. : The FSD-based NC-MRA technique is improved in the depiction of multidirectional flow by applying a 2-module FSD preparation, which enhances its potential to serve as an alternative magnetic resonance angiography technique for the assessment of hand vascular abnormalities.

  14. Contrast-enhanced three-dimensional fast-spoiled gradient magnetic resonance angiography of the renal arteries for potential living renal transplant donors: a comparative study with digital subtraction angiography

    International Nuclear Information System (INIS)

    Al-Saeed, O.; Sheikh, M.; Al-Khawari, H.; Ismail, M.; Al-Moosawi, M.

    2005-01-01

    Preoperative assessment of the arterial anatomy of prospective renal donors is essential. Various non-invasive techniques are used for such evaluation. We conducted this study using contrast-enhanced 3-D fast-spoiled gradient (CE 3-D FSPGR) magnetic resonance angiography (MRA) on a 1.0 Tesla magnet, for preoperative definition of the renal arteries. Forty-five preoperative living renal donors underwent CE 3-D FSPGR MRA of the renal vessels and the results were compared with conventional digital subtraction angiography (DSA). The renal vascular anatomy, both normal and with variations, was satisfactorily defined in all 45 cases with CE 3-D FSPGR MRA. Fifteen cases showed an accessory or aberrant arterial supply. A small aneurysm was shown in one case. All cases compared well with conventional DSA. Our study revealed that CE 3-D FSPGR MRA on a lower field strength magnet is accurate in defining the renal vascular anatomy and its variations. Copyright (2005) Blackwell Science Pty Ltd

  15. Magnetic Resonance angiography with bolus contrast agent in abdominal aortic aneurysms

    International Nuclear Information System (INIS)

    Di Cesare, E.; Cerone, G.; Giordano, A.V.; Marsili, L.; Barile, A.; Michelini, O.; Masciocchi, C.; Spartera, C.

    2000-01-01

    Purpose of this paper is to investigate the potentials of 3D breath-hold contrast-enhanced Magnetic Resonance Angiography (MRA) in the diagnosis, follow-up and treatment planning of abdominal aortic aneurysms. Twenty-four patients with infrarenal aortic aneurysm underwent MRA. It was used a 1.5 T unit (GE Horizon, Echospeed 8.2), a phased array surface coil and 3D Fast SPGR T1-weighted sequences acquired on the coronal plane during patient breath-hold and after contrast agent i.v. administration. A bolus-test was done before angiography to optimize imaging delay time. After 3D MRA a Fast-SPGR T1-weighted sequence was acquired on the axial plane. The 3D MRA source images were processed with the MIP algorithm. Qualitative and quantitative analyses were carried out. Helical CT was performed in 6 cases and DSA in 7 cases. Surgery was the reference standard in 15 patients. MRA depicted aneurysm thrombosis in 22 cases, carrefour involvement in 18 cases and iliac arteries involvement in 3 cases. Accessory renal arteries were shown in 4 cases; iliac artery stenosis was associated in 5 cases. There was agreement between MR and Helical CT and DSA findings: surgery confirmed MRA results in 15/15 cases. 3D contrast-enhanced MRA can be considered the method of choice in the follow-up and treatment planning of abdominal aortic aneurysms, because it provides both angiographic and tomographic images: this allows to obtain more information, noninvasively and without the use of ionizing radiations [it

  16. Localization strategy for magnetic resonance coronary angiography

    International Nuclear Information System (INIS)

    Cheng Liuquan; Gao Yuangui; Sun Wei; Sheng Fugeng; Cai Youquan

    2003-01-01

    Objective: To develop a localization strategy for magnetic resonance coronary angiography (MRCA). Methods: In 89 subjects, the standard 4-chamber view and long-axis view of left and right ventricle were acquired using Fast-Imaging-Employing-Steady-State-Acquisition (FIESTA) sequence in CINE mode, and the trigger-delay time for mid-diastolic phase was determined. Coronary vessels including right coronary artery (RCA), left main (LM), left anterior descending (LAD), and left circumflex (LCX) were localized and imaged using 3- dimensional fat-suppressed FIESTA sequence during end-expiration. The reproducibility of the localization strategy was evaluated by taking the standard of coronary segmentation system recommended by American Heart Association. Results: Eighty-six subjects completed the examination with full respiratory co-operation and the indication ratio was 96.63%. Nine planes were optimized as the standard to target the main branches of coronary arteries, and a comprehensive reproducibility reached 100% in demonstrating the proximal and middle segment of RCA (AHA-18, 19), LM (AHA-1, 2), proximal and middle segment of LAD (AHA-3, 5, 7), and proximal LCX (AHA-10). The reproducibility for the demonstration of distal segments of LAD, LCX, and RCA (AHA-9, 14, 21) was 94.19%, 72.09%, and 96.51%, respectively. Conclusion: This is a simple and practical localization strategy for MRCA. It could image the proximal and middle segments of the coronary arteries with good reproducibility, which indicates the potential for clinical application

  17. Evaluation of the vascular anatomy in potential living kidney donors with gadolinium-enhanced magnetic resonance angiography: comparison with digital subtraction angiography and intraoperative findings.

    Science.gov (United States)

    Asgari, Majid A; Dadkhah, Farid; Ghadian, Ali R; Razzaghi, Mohammad R; Noorbala, Mohammad H; Amini, Erfan

    2011-01-01

    X-ray contrast arteriography has traditionally been used for pre-operative evaluation in living kidney donors. However, magnetic resonance angiography (MRA) offers a non-invasive alternative, which has been considered to be less accurate. This study was performed to determine whether MRA in the pre-operative investigation of living kidney donors provides sufficient information. From December 2005 to December 2007, 173 potential live donors were evaluated in this study. Donors performed digital subtraction angiography (DSA) and those with one or more accessory arteries at least on one side recruited for further evaluation with three-dimensional gadolinium-enhanced MRA. A total of 30 donors constituted the study population. When compared with DSA as the reference method, MRA detected 20 of 36 renal accessory arteries which indicates a sensitivity of 55.6%. The difference between MRA and DSA in identifying accessory renal arteries was significant (p-value kidneys. MRA has the advantage of avoiding exposure to ionizing radiation and is non-invasive. These are important considerations in pre-operative evaluation of a generally healthy donor population. However, MRA provides suboptimal accuracy in detecting small accessory arteries. © 2010 John Wiley & Sons A/S.

  18. Gadofosveset-enhanced magnetic resonance angiography as a means of evaluating pulmonary arteriovenous malformation: a case report.

    Science.gov (United States)

    Pressacco, Josephine; Papas, Konstantin

    2012-07-01

    This case report is a unique presentation of a new potential indication for Gadofosvest (Ablavar), a blood pool contrast agent for magnetic resonance angiography (MRA). Ablavar is an excellent MRA contrast agent because it provides optimal contrast opacification of both the arterial and venous system, unlike the conventional extracellular agents that are used for arterial imaging only. The present case report demonstrates the ability of Ablavar to demonstrate pulmonary arteriovenous malformation (AVM), showing both its arterial feeders as well as its venous drainage tract. Crown Copyright © 2012. Published by Elsevier Inc. All rights reserved.

  19. The increased use of computed tomography angiography and magnetic resonance angiography as the sole imaging modalities prior to infrainguinal bypass has had no effect on outcomes.

    Science.gov (United States)

    Shue, Bing; Damle, Rachelle N; Flahive, Julie; Kalish, Jeffrey A; Stone, David H; Patel, Virendra I; Schanzer, Andres; Baril, Donald T

    2015-08-01

    Angiography remains the gold standard imaging modality before infrainguinal bypass. Computed tomography angiography (CTA) and magnetic resonance angiography (MRA) have emerged as noninvasive alternatives for preoperative imaging. We sought to examine contemporary trends in the utilization of CTA and MRA as isolated imaging modalities before infrainguinal bypass and to compare outcomes following infrainguinal bypass in patients who underwent CTA or MRA versus those who underwent conventional arteriography. Patients undergoing infrainguinal bypass within the Vascular Study Group of New England were identified (2003-2012). Patients were stratified by preoperative imaging modality: CTA/MRA alone or conventional angiography. Trends in utilization of these modalities were examined and demographics of these groups were compared. Primary end points included primary patency, secondary patency, and major adverse limb events (MALE) at 1 year as determined by Kaplan-Meier analysis. Multivariable Cox proportional hazards models were constructed to evaluate the effect of imaging modality on primary patency, secondary patency, and MALE after adjusting for confounders. In 3123 infrainguinal bypasses, CTA/MRA alone was used in 462 cases (15%) and angiography was used in 2661 cases (85%). Use of CTA/MRA alone increased over time, with 52 (11%) bypasses performed between 2003 and 2005, 189 (41%) bypasses performed between 2006 and 2009, and 221 (48%) bypasses performed between 2010 and 2012 (P < 0.001). Patients with CTA/MRA alone, compared with patients with angiography, more frequently underwent bypass for claudication (33% vs. 26%, P = 0.001) or acute limb ischemia (13% vs. 5%, P < 0.0001), more frequently had prosthetic conduits (39% vs. 30%, P = 0.001), and less frequently had tibial/pedal targets (32% vs. 40%, P = 0.002). After adjusting for these and other confounders, multivariable analysis demonstrated that the use of CTA/MRA alone was not associated with a significant

  20. The optimization of scan timing for contrast-enhanced magnetic resonance angiography

    International Nuclear Information System (INIS)

    Lee, Jong Min; Chang, Yong Min; Ryeom, Hun Kyu; Lee, Sang Kwon; Kim, Yong Sun; Kang, Duk Sik; Tirman, Philip J.

    2000-01-01

    To determine the optimal scan timing for contrast-enhanced magnetic resonance angiography and to evaluate a new timing method based on the arteriovenous circulation time. Eighty-nine contrast-enhanced magnetic resonance angiographic examinations were performed mainly in the extremities. A 1.5T scanner with a 3-D turbo-FLASH sequence was used, and during each study, two consecutive arterial phases and one venous phase were acquired. Scan delay time was calculated from the time-intensity curve by the traditional (n = 48) and/or the new (n = 41) method. This latter was based on arteriovenous circulation time rather than peak arterial enhancement time, as used in the traditional method. The numbers of first-phase images showing a properly enhanced arterial phase were compared between the two methods. Mean scan delay time was 5.4 sec longer with the new method than with the traditional. Properly enhanced first-phase images were found in 65% of cases (31/48) using the traditional timing method, and 95% (39/41) using the new method. When cases in which there was mismatch between the target vessel and the Time-intensity curve acquisition site are excluded, erroneous acquisition occurred in seven cases with the traditional method, but in none with the new method. The calculation of scan delay time on the basis of arteriovenous circulation time provides better timing for arterial phase acquisition than the traditional method

  1. Fat-Suppressed Gadolinium-Enhanced Three-Dimensional Magnetic Resonance Angiography Adequately Depicts the Status of Iliac Arteries Following Atherectomy and Stent Placement

    International Nuclear Information System (INIS)

    Amano, Yasuo; Gemma, Kazuhito; Kawamata, Hiroshi; Kumazaki, Tatsuo

    1998-01-01

    Fat-suppressed, three-dimensional magnetic resonance angiography (3D MRA) was performed on nine patients with 11 iliac artery stenoses following atherectomy or stent placement. The MRA accurately depicted continued patency, restenosis, or aneurysm formation when compared with immediate posttreatment conventional arteriography. Therefore MRA is accurate and can be used independently for clinical decision making

  2. Magnetic resonance angiography

    Science.gov (United States)

    ... Saunders; 2015:chap 17. Litt H, Carpenter JP. Magnetic resonance imaging. In: Cronenwett JL, Johnston KW, eds. Rutherford's Vascular Surgery . 8th ed. Philadelphia, PA: Elsevier Saunders; 2014:chap ...

  3. Usefulness of magnetic resonance angiography in diagnosis of peripheral vascular disease

    International Nuclear Information System (INIS)

    Kuga, Takayuki; Akiyama, Norio; Takenaka, Hiroaki; Fujioka, Kentaro; Zempo, Noriya; Esato, Kensuke

    1992-01-01

    The diagnostic usefulness of magnetic resonance angiography (MRA) was evaluated in 19 patients with peripheral vascular disease. It takes thirty minutes or less to perform this test, without any complications. The percent of correct diagnosis on obstructive and stenotic region was 75% in cases of deep vein thrombosis. In addition, it was easy to diagnose an existence of a graft patent. However, it was unsatisfactory to understand morphologic changes of an iliac artery and to determine the position of grafting. The position and size of dilatation and existence of thrombus were easily evaluated in patients with venous aneurysm and varicose vein. MRA was a non-invasive, short spending time imaging. It was available for pregnant women and people with drug allergy, heart failure or renal failure. We believe that MRA can be used in the preoperative examination and the evaluation of the postoperative complications in the peripheral vascular diseases. (J.P.N.)

  4. Usefulness of magnetic resonance angiography in diagnosis of peripheral vascular disease

    Energy Technology Data Exchange (ETDEWEB)

    Kuga, Takayuki; Akiyama, Norio; Takenaka, Hiroaki; Fujioka, Kentaro; Zempo, Noriya; Esato, Kensuke (Yamaguchi Univ., Ube (Japan). School of Medicine)

    1992-03-01

    The diagnostic usefulness of magnetic resonance angiography (MRA) was evaluated in 19 patients with peripheral vascular disease. It takes thirty minutes or less to perform this test, without any complications. The percent of correct diagnosis on obstructive and stenotic region was 75% in cases of deep vein thrombosis. In addition, it was easy to diagnose an existence of a graft patent. However, it was unsatisfactory to understand morphologic changes of an iliac artery and to determine the position of grafting. The position and size of dilatation and existence of thrombus were easily evaluated in patients with venous aneurysm and varicose vein. MRA was a non-invasive, short spending time imaging. It was available for pregnant women and people with drug allergy, heart failure or renal failure. We believe that MRA can be used in the preoperative examination and the evaluation of the postoperative complications in the peripheral vascular diseases. (J.P.N.).

  5. Gadolinium-enhanced magnetic resonance angiography in neonates and infants suspected of caval or aortic thrombosis

    International Nuclear Information System (INIS)

    Greenberg, S. Bruce; Bhutta, Sadaf T.; Buchmann, Robert F.

    2004-01-01

    Gadolinium-enhanced magnetic resonance angiography (MRA)is a well-established technique in older children and adults. No studies have focused on its use in neonates and small infants. Our objective was to study the use of gadolinium-enhanced MRA in neonates and infants suspected of caval or aortic thrombosis. Materials and Methods:Gadolinium-enhanced MR angiography was performed on seven neonates and small infants for the evaluation of caval or aortic thrombosis. Gadolinium-DTPA at a dose of 0.3 mmol/kg (minimum dose 1 ml) was injected using a power injector (0.2 ml/s). Contrast-enhanced MRA was performed using a 3-D, fast, radiofrequency spoiled gradient-echo sequence (TR/TE: 4.8/1.1, flip angle 45 , matrix 256 x 128, slice thickness 2.6 mm interpolated to 1.3 mm, FOV variable, NEX=1.0). Diagnostic-quality angiograms were obtained in all seven neonates. Superior vena cava thrombosis was identified in two neonates, and abdominal aortic thrombosis was present in one neonate. It is practical to perform gadolinium-enhanced MRA in neonates weighing as little as 600 g for the detection of caval or aortic thrombosis. (orig.)

  6. Gadolinium-enhanced magnetic resonance angiography in neonates and infants suspected of caval or aortic thrombosis

    Energy Technology Data Exchange (ETDEWEB)

    Greenberg, S. Bruce; Bhutta, Sadaf T.; Buchmann, Robert F. [University of Arkansas for Medical Sciences, Arkansas Children' s Hospital, Little Rock, AR (United States)

    2004-12-01

    Gadolinium-enhanced magnetic resonance angiography (MRA)is a well-established technique in older children and adults. No studies have focused on its use in neonates and small infants. Our objective was to study the use of gadolinium-enhanced MRA in neonates and infants suspected of caval or aortic thrombosis. Materials and Methods:Gadolinium-enhanced MR angiography was performed on seven neonates and small infants for the evaluation of caval or aortic thrombosis. Gadolinium-DTPA at a dose of 0.3 mmol/kg (minimum dose 1 ml) was injected using a power injector (0.2 ml/s). Contrast-enhanced MRA was performed using a 3-D, fast, radiofrequency spoiled gradient-echo sequence (TR/TE: 4.8/1.1, flip angle 45 , matrix 256 x 128, slice thickness 2.6 mm interpolated to 1.3 mm, FOV variable, NEX=1.0). Diagnostic-quality angiograms were obtained in all seven neonates. Superior vena cava thrombosis was identified in two neonates, and abdominal aortic thrombosis was present in one neonate. It is practical to perform gadolinium-enhanced MRA in neonates weighing as little as 600 g for the detection of caval or aortic thrombosis. (orig.)

  7. Breath-hold two-dimensional MR angiography of coronary arteries. Comparison with conventional coronary angiography in ten cases

    International Nuclear Information System (INIS)

    Li Liwei; Zhang Wanshi; Liu Chaozhong; Lu Xiaoyan; Xu Jiaxing

    1997-01-01

    Purpose: To assess the diagnostic value of two-dimensional coronary magnetic resonance (MR) angiography in patients evaluated for ischemic heart disease. Materials and methods: Ten patients who underwent selective cardiac catheterization with coronary MR angiography were evaluated with two-dimensional coronary MR angiography. Coronary MR angiography was performed with breath-hold fat-suppressed ECG-gated Turbo-FLASH with K-space segmentation using a 1.5 T imager. Results: The left main coronary artery, proximal left anterior descending artery, circumflex artery and right coronary artery were demonstrated in all cases. Continuous segments (mean) of left anterior descending, circumflex and right coronary arteries visualized on MRA were 6.72 +- 3.16 cm, 3.67 +- 4.81 cm and 7.93 +- 3.12 cm respectively. The overall sensitivity for detection of hemodynamically significant coronary artery lesion (≥50%) was 62.5% respectively. Conclusion: Breath-hold two-dimensional coronary MR angiography was useful in showing relatively long segments of the main coronary arteries and also has potential in depicting hemodynamically significant coronary artery lesions

  8. Magnetic resonance angiography in 12 patients with Wallenberg's syndrome

    International Nuclear Information System (INIS)

    Watanabe, Masaki; Takahashi, Akira; Hashizume, Yoshio; Motegi, Yoshimasa; Furuse, Masahiro.

    1992-01-01

    Magnetic resonance angiography (MRA) was performed in 12 patients with Wallenberg's syndrome (WS) in chronic stage to investigate the lesion of the vertebral artery (VA). The laterality of infarction in the medulla oblongata was confirmed with MRI; the right in four patients and the left in eight. In this study, time-of-flight MRA was evaluated. Coronal and OM sections in MRA were examined, because the former is useful to observe asymmetry and curve of the cervical VA, and the latter is useful to observe asymmetry and stenosis of the intracranial VA. In nine out of 12 patients, the ipsilateral VA was rather hypoplastic compared to the contralateral VA, and the flow of the hypoplastic VA stopped before and after entering the intracranial region. The contralateral VA of the hypoplastic cases showed curve in the neck in five patients and stenosis in the intracranial portion in one patient. A comparative study was conducted between vertebral angiogram (VAG) and MRA in four patients. Both VAG and MRA were useful in detecting hypoplasia and stoppage of the flow. It was considered that VA hypoplasia is frequently responsible for WS, and that MRA is useful in screening the vascular lesion as a non-invasive procedure to reveal changes of the bilateral VA. (author)

  9. Transluminal color-coded three-dimensional magnetic resonance angiography for visualization of signal Intensity distribution pattern within an unruptured cerebral aneurysm: preliminarily assessment with anterior communicating artery aneurysms

    International Nuclear Information System (INIS)

    Satoh, T.; Ekino, C.; Ohsako, C.

    2004-01-01

    The natural history of unruptured cerebral aneurysm is not known; also unknown is the potential growth and rupture in any individual aneurysm. The authors have developed transluminal color-coded three-dimensional magnetic resonance angiography (MRA) obtained by a time-of-flight sequence to investigate the interaction between the intra-aneurysmal signal intensity distribution patterns and configuration of unruptured cerebral aneurysms. Transluminal color-coded images were reconstructed from volume data of source magnetic resonance angiography by using a parallel volume-rendering algorithm with transluminal imaging technique. By selecting a numerical threshold range from a signal intensity opacity chart of the three-dimensional volume-rendering dataset several areas of signal intensity were depicted, assigned different colors, and visualized transparently through the walls of parent arteries and an aneurysm. Patterns of signal intensity distribution were analyzed with three operated cases of an unruptured anterior communicating artery aneurysm and compared with the actual configurations observed at microneurosurgery. A little difference in marginal features of an aneurysm was observed; however, transluminal color-coded images visualized the complex signal intensity distribution within an aneurysm in conjunction with aneurysmal geometry. Transluminal color-coded three-dimensional magnetic resonance angiography can thus provide numerical analysis of the interaction between spatial signal intensity distribution patterns and aneurysmal configurations and may offer an alternative and practical method to investigate the patient-specific natural history of individual unruptured cerebral aneurysms. (orig.)

  10. Magnetic resonance angiography with blood-pool contrast agents: future applications

    International Nuclear Information System (INIS)

    Fink, C.; Goyen, M.; Lotz, J.

    2007-01-01

    Blood pool agents remain in the intravascular space for a longer time period. Therefore the optimal imaging window for vascular structures is widened to about 30 minutes. Gadofosveset trisodium (Vasovist, Bayer Schering Pharma AG, Berlin, Germany) is the first blood-pool contrast agent approved in Europe for contrast-enhanced magnetic resonance angiography (MRA) of vessels in the abdomen, pelvis and lower extremity in adults. Other possible applications of blood-pool agents are now being considered, such as assessment of venous thromboembolism, coronary artery disease or sinus venous thrombosis. Perfusion MR imaging holds promise for detecting lung perfusion defects with higher spatial resolution and reduced scan time compared with radionuclide scintigraphy. In coronary artery disease, blood-pool agents enable a substantial increase in the quality of coronary artery imaging. Quantitative myocardial perfusion and myocardial viability seem to be possible, although modifications in protocols and sequence design are necessary for optimal results. Other novel applications of blood-pool agents include monitoring of inflammatory changes in systemic lupus erythematosus and evaluation of tumour invasion into lymph nodes and more reliable assessment of cerebral venous and sinus thrombosis. (orig.)

  11. Magnetic resonance angiography with blood-pool contrast agents: future applications

    Energy Technology Data Exchange (ETDEWEB)

    Fink, C. [Univ. Hospitals, Grosshadern, Munich (Germany); Goyen, M. [Univ. Medical Center, Hamburg-Eppendorf, Hamburg (Germany); Lotz, J. [Hannover Medical School, Hannover (Germany)

    2007-03-15

    Blood pool agents remain in the intravascular space for a longer time period. Therefore the optimal imaging window for vascular structures is widened to about 30 minutes. Gadofosveset trisodium (Vasovist, Bayer Schering Pharma AG, Berlin, Germany) is the first blood-pool contrast agent approved in Europe for contrast-enhanced magnetic resonance angiography (MRA) of vessels in the abdomen, pelvis and lower extremity in adults. Other possible applications of blood-pool agents are now being considered, such as assessment of venous thromboembolism, coronary artery disease or sinus venous thrombosis. Perfusion MR imaging holds promise for detecting lung perfusion defects with higher spatial resolution and reduced scan time compared with radionuclide scintigraphy. In coronary artery disease, blood-pool agents enable a substantial increase in the quality of coronary artery imaging. Quantitative myocardial perfusion and myocardial viability seem to be possible, although modifications in protocols and sequence design are necessary for optimal results. Other novel applications of blood-pool agents include monitoring of inflammatory changes in systemic lupus erythematosus and evaluation of tumour invasion into lymph nodes and more reliable assessment of cerebral venous and sinus thrombosis. (orig.)

  12. Three-dimensional dynamic magnetic resonance angiography for the evaluation of radiosurgically treated cerebral arteriovenous malformations

    International Nuclear Information System (INIS)

    Gauvrit, Jean-Yves; Oppenheim, Catherine; Naggara, Olivier; Trystram, Denis; Fredy, Daniel; Meder, Jean-Francois; Nataf, Francois; Roux, Francois-Xavier; Munier, Thierry; Pruvo, Jean-Pierre; Leclerc, Xavier

    2006-01-01

    We assessed the value of three-dimensional (3D) dynamic magnetic resonance angiography (MRA) for the follow-up of patients with radiosurgically treated cerebral arteriovenous malformations (AVMs). Fifty-four patients with cerebral AVMs treated by radiosurgery (RS) were monitored using conventional catheter angiography (CCA) and 3D dynamic MRA with sensitivity encoding based on the parallel imaging. Cerebral AVM was qualitatively classified by two radiologists into one of five categories in terms of residual nidus size and persistence of early draining vein (I, >6 cm; II, 3-6 cm; III, <3 cm; IV, isolated early draining vein; V, complete obliteration). 3D MRA findings showed a good agreement with CCA in 40 cases (κ=0.62). Of 23 nidus detected on CCA, 3D dynamic MRA showed 14 residual nidus. Of 28 occluded nidus on 3D dynamic MRA, 22 nidus were occluded on CCA. The sensitivity and specificity of 3D dynamic MRA for the detection of residual AVM were 81% and 100%. 3D dynamic MRA after RS may therefore be useful in association with MRI and can be repeated as long as opacification of the nidus or early venous drainage persists, one CCA remaining indispensable to affirm the complete occlusion at the end of follow-up. (orig.)

  13. Ferumoxytol-enhanced magnetic resonance angiography for the assessment of potential kidney transplant recipients

    Energy Technology Data Exchange (ETDEWEB)

    Stoumpos, Sokratis; Mark, Patrick B. [Queen Elizabeth University Hospital, Renal and Transplant Unit, Glasgow (United Kingdom); University of Glasgow, Institute of Cardiovascular and Medical Sciences, BHF Glasgow Cardiovascular Research Centre, Glasgow (United Kingdom); Hennessy, Martin; Kasthuri, Ram; Roditi, Giles [Queen Elizabeth University Hospital, Department of Radiology, Glasgow (United Kingdom); Vesey, Alex T.; Kingsmore, David B. [Queen Elizabeth University Hospital, Renal and Transplant Unit, Glasgow (United Kingdom); Radjenovic, Aleksandra [University of Glasgow, Institute of Cardiovascular and Medical Sciences, BHF Glasgow Cardiovascular Research Centre, Glasgow (United Kingdom)

    2018-01-15

    Traditional contrast-enhanced methods for scanning blood vessels using magnetic resonance imaging (MRI) or CT carry potential risks for patients with advanced kidney disease. Ferumoxytol is a superparamagnetic iron oxide nanoparticle preparation that has potential as an MRI contrast agent in assessing the vasculature. Twenty patients with advanced kidney disease requiring aorto-iliac vascular imaging as part of pre-operative kidney transplant candidacy assessment underwent ferumoxytol-enhanced magnetic resonance angiography (FeMRA) between December 2015 and August 2016. All scans were performed for clinical indications where standard imaging techniques were deemed potentially harmful or inconclusive. Image quality was evaluated for both arterial and venous compartments. First-pass and steady-state FeMRA using incremental doses of up to 4 mg/kg body weight of ferumoxytol as intravenous contrast agent for vascular enhancement was performed. Good arterial and venous enhancements were achieved, and FeMRA was not limited by calcification in assessing the arterial lumen. The scans were diagnostic and all patients completed their studies without adverse events. Our preliminary experience supports the feasibility and utility of FeMRA for vascular imaging in patients with advanced kidney disease due for transplant listing, which has the advantages of obtaining both arteriography and venography using a single test without nephrotoxicity. (orig.)

  14. Follow-up after embolization of ruptured intracranial aneurysms: A prospective comparison of two-dimensional digital subtraction angiography, three-dimensional digital subtraction angiography, and time-of-flight magnetic resonance angiography

    International Nuclear Information System (INIS)

    Serafin, Zbigniew; Strzesniewski, Piotr; Lasek, Wladyslaw; Beuth, Wojciech

    2012-01-01

    To prospectively compare of the diagnostic value of digital subtraction angiography (DSA) and time-of-flight magnetic resonance angiography (TOF-MRA) in the follow-up of intracranial aneurysms after endovascular treatment. Seventy-two consecutive patients were examined 3 months after the embolization. The index tests included: two-dimensional DSA (2D-DSA), three-dimensional DSA (3D-DSA), and TOF-MRA. The reference test was a retrospective consensus between 2D-DSA images, 3D-DSA images, and source rotational DSA images. The evaluation included: detection of the residual flow, quantification of the flow, and validity of the decision regarding retreatment. Intraobserver agreement and interobserver agreement were determined. The sensitivity and specificity of residual flow detection ranged from 84.6 % (2D-DSA and TOF-MRA) to 92.3 % (3D-DSA) and from 91.3 % (TOF-MRA) to 97.8 % (3D-DSA), respectively. The accuracy of occlusion degree evaluation ranged from 0.78 (2D-DSA) to 0.92 (3D-DSA, Cohen's kappa). The 2D-DSA method presented lower performance in the decision on retreatment than 3D-DSA (P < 0.05, ROC analysis). The intraobserver agreement was very good for all techniques (κ = 0.80-0.97). The interobserver agreement was moderate for TOF-MRA and very good for 2D-DSA and 3D-DSA (κ = 0.72-0.94). Considering the invasiveness of DSA and the minor difference in the diagnostic performance between 3D-DSA and TOF-MRA, the latter method should be the first-line modality for follow-up after aneurysm embolization. (orig.)

  15. Magnetostatic wave tunable resonators

    Science.gov (United States)

    Castera, J.-P.; Hartemann, P.

    1983-06-01

    Theoretical principles and techniques for the implementation of magnetostatic surface wave and volume wave resonators in high frequency oscillators are discussed. Magnetostatic waves are magnetic waves that propagate in materials exposed to a polarized magnetic field. The propagation speed ranges from 3-300 km/sec for wavelengths between 1 micron and 10 mm, in the presence of lags from 10-1000 nsec/ cm. Tunable resonators in the 1-20 GHz frequency range have been manufactured with YIG using liquid phase epitaxy for deposition on gadolinium and gallium substrates. Distributed-mirror Fabry-Perot cavity resonators are described and performance tests results are reported, including losses of 8 dB, a quality coefficient under voltage of 450, and frequency rejection outside of resonance better than 10 dB. However, saturation occurs at low power levels at frequencies lower than 4.2 GHz, a feature overcome with forward volume magnetostatic wave generators, which have a quality factor of 500, an insertion loss of 22 dB, and rejection around 15 dB.

  16. Contrast-enhanced three-dimensional magnetic resonance angiography of the aorta and its branches. Clinical applications for a new angiographic technique

    International Nuclear Information System (INIS)

    Dolz, J. L.; Vilanova, J. C.; Huguet, M.; Delgado, E.; Baquero, M.; Blanch, A.; Aldoma, J.; Capdevila, A.

    1999-01-01

    Magnetic resonance angiography (MRA) for the study of the aorta has developed at an impressive rate in recent years. It is now possible to evaluate the aorta and its branches by means of magnetic resonance (MR) following administration via peripheral vein of a paramagnetic contrast agent. The approach is similar to that of conventional arteriography, but without the risk associated with iodinated contrast media or invasive arterial catheterization. The technique involves the use of a sequence of ultrafast three-dimensional gradient-echo pulses acquired during apnea. This process enables angiographic or volumetric visualization in the desired plane. The objective of the present report is to describe the technique and demonstrate its many clinical applications. (Author) 23 refs

  17. Magnetic resonance angiography in infrapopliteal arterial disease: prospective comparison of 1.5 and 3 Tesla magnetic resonance imaging.

    Science.gov (United States)

    Diehm, Nicolas; Kickuth, Ralph; Baumgartner, Iris; Srivastav, Sudesh K; Gretener, Silvia; Husmann, Marc J; Jaccard, Yves; Do, Do Dai; Triller, Juergen; Bonel, Harald M

    2007-06-01

    To prospectively determine the accuracy of 1.5 Tesla (T) and 3 T magnetic resonance angiography (MRA) versus digital subtraction angiography (DSA) in the depiction of infrageniculate arteries in patients with symptomatic peripheral arterial disease. A prospective 1.5 T, 3 T MRA, and DSA comparison was used to evaluate 360 vessel segments in 10 patients (15 limbs) with chronic symptomatic peripheral arterial disease. Selective DSA was performed within 30 days before both MRAs. The accuracy of 1.5 T and 3 T MRA was compared with DSA as the standard of reference by consensus agreement of 2 experienced readers. Signal-to-noise ratios (SNR) and signal-difference-to-noise ratios (SDNRs) were quantified. No significant difference in overall image quality, sufficiency for diagnosis, depiction of arterial anatomy, motion artifacts, and venous overlap was found comparing 1.5 T with 3 T MRA (P > 0.05 by Wilcoxon signed rank and as by Cohen k test). Overall sensitivity of 1.5 and 3 T MRA for detection of significant arterial stenosis was 79% and 82%, and specificity was 87% and 87% for both modalities, respectively. Interobserver agreement was excellent k > 0.8, P < 0.05) for 1.5 T as well as for 3 T MRA. SNR and SDNR were significantly increased using the 3 T system (average increase: 36.5%, P < 0.032 by t test, and 38.5%, P < 0.037 respectively). Despite marked improvement of SDNR, 3 T MRA does not yet provide a significantly higher accuracy in diagnostic imaging of atherosclerotic lesions below the knee joint as compared with 1.5 T MRA.

  18. Improvement in transmission loss of aircraft double wall with resonators

    Science.gov (United States)

    Sun, Jincai; Shi, Liming; Ye, Xining

    1991-08-01

    A little volume low frequency resonator applicable to double-wall configuration of propeller-driven aircraft was designed on the basis of the principle of Helmholtz resonator. The normal incidence absorption coefficient of the various single resonator has been measured. The agreement between theoretical and experimental results is encouraging. An array of resonators whose resonant frequency at 85 Hz and 160 Hz, respectively, are installed between aircraft double-panel, and it has been shown that transmission loss of the double wall structure with resonators improve 4 dB and 6.5 dB in 1/3rd octave bandwidth at 80 Hz and 160 Hz center frequency, respectively, and 5 dB and 7 dB at resonant frequencies, compared with that of the double wall configuration without resonators.

  19. Incidental findings of persistent primitive trigeminal artery on 3-dimensional time-of-flight magnetic resonance angiography at 3.0 T: an analysis of 25 cases.

    Science.gov (United States)

    Chen, Yuan-Chang; Li, Ming-Hua; Chen, Shi-Wen; Hu, Ding-Jun; Qiao, Rui-Hua

    2011-04-01

    Currently, the presence of persistent primitive trigeminal artery (PPTA) is detected by digital subtraction angiography (DSA); most publications on this cerebrovascular variation have been individual case reports. This study is to evaluate the efficacy of 3-dimensional time-of-flight magnetic resonance angiography (3D-TOF MRA) at 3.0 T for the detection and classification of PPTA based on a large case series. Between June 2007 and October 2008, 4,650 patients underwent magnetic resonance angiography (MRA) examination at 3.0 T in our hospital. MRA was performed using 3D-TOF with volume rendering (VR) and maximum intensity projection (MIP) technique. The PPTA was classified according to the Saltzman classification system. The occurrence of cerebral vascular diseases accompanying PPTA was studied. Among the 4,650 patients with MRA examined, 25 were identified as having PPTA; the prevalence of PPTA was .54%. The Saltzman classification of PPTAs was as follows: type I, 24%; type II, 16%; type III, 60%. Sixteen percent of the cases with PPTA were accompanied with intracranial aneurysm. A 3D-TOF MRA at 3.0 T can be used for the detection of PPTA and making a classification of PPTA indirectly. The incidence of PPTA with type III was greater than that of other types of PPTA. Intracranial aneurysm appeared to be associated with PPTA. Copyright © 2010 by the American Society of Neuroimaging.

  20. Follow-up after embolization of ruptured intracranial aneurysms: a prospective comparison of two-dimensional digital subtraction angiography, three-dimensional digital subtraction angiography, and time-of-flight magnetic resonance angiography.

    Science.gov (United States)

    Serafin, Zbigniew; Strześniewski, Piotr; Lasek, Władysław; Beuth, Wojciech

    2012-11-01

    To prospectively compare of the diagnostic value of digital subtraction angiography (DSA) and time-of-flight magnetic resonance angiography (TOF-MRA) in the follow-up of intracranial aneurysms after endovascular treatment. Seventy-two consecutive patients were examined 3 months after the embolization. The index tests included: two-dimensional DSA (2D-DSA), three-dimensional DSA (3D-DSA), and TOF-MRA. The reference test was a retrospective consensus between 2D-DSA images, 3D-DSA images, and source rotational DSA images. The evaluation included: detection of the residual flow, quantification of the flow, and validity of the decision regarding retreatment. Intraobserver agreement and interobserver agreement were determined. The sensitivity and specificity of residual flow detection ranged from 84.6 % (2D-DSA and TOF-MRA) to 92.3 % (3D-DSA) and from 91.3 % (TOF-MRA) to 97.8 % (3D-DSA), respectively. The accuracy of occlusion degree evaluation ranged from 0.78 (2D-DSA) to 0.92 (3D-DSA, Cohen's kappa). The 2D-DSA method presented lower performance in the decision on retreatment than 3D-DSA (P < 0.05, ROC analysis). The intraobserver agreement was very good for all techniques (κ = 0.80-0.97). The interobserver agreement was moderate for TOF-MRA and very good for 2D-DSA and 3D-DSA (κ = 0.72-0.94). Considering the invasiveness of DSA and the minor difference in the diagnostic performance between 3D-DSA and TOF-MRA, the latter method should be the first-line modality for follow-up after aneurysm embolization.

  1. Follow-up after embolization of ruptured intracranial aneurysms: A prospective comparison of two-dimensional digital subtraction angiography, three-dimensional digital subtraction angiography, and time-of-flight magnetic resonance angiography

    Energy Technology Data Exchange (ETDEWEB)

    Serafin, Zbigniew; Strzesniewski, Piotr; Lasek, Wladyslaw [Nicolaus Copernicus University, Collegium Medicum, Department of Radiology and Diagnostic Imaging, Bydgoszcz (Poland); Beuth, Wojciech [Nicolaus Copernicus University, Collegium Medicum, Department of Neurosurgery and Neurotraumatology, Bydgoszcz (Poland)

    2012-11-15

    To prospectively compare of the diagnostic value of digital subtraction angiography (DSA) and time-of-flight magnetic resonance angiography (TOF-MRA) in the follow-up of intracranial aneurysms after endovascular treatment. Seventy-two consecutive patients were examined 3 months after the embolization. The index tests included: two-dimensional DSA (2D-DSA), three-dimensional DSA (3D-DSA), and TOF-MRA. The reference test was a retrospective consensus between 2D-DSA images, 3D-DSA images, and source rotational DSA images. The evaluation included: detection of the residual flow, quantification of the flow, and validity of the decision regarding retreatment. Intraobserver agreement and interobserver agreement were determined. The sensitivity and specificity of residual flow detection ranged from 84.6 % (2D-DSA and TOF-MRA) to 92.3 % (3D-DSA) and from 91.3 % (TOF-MRA) to 97.8 % (3D-DSA), respectively. The accuracy of occlusion degree evaluation ranged from 0.78 (2D-DSA) to 0.92 (3D-DSA, Cohen's kappa). The 2D-DSA method presented lower performance in the decision on retreatment than 3D-DSA (P < 0.05, ROC analysis). The intraobserver agreement was very good for all techniques ({kappa} = 0.80-0.97). The interobserver agreement was moderate for TOF-MRA and very good for 2D-DSA and 3D-DSA ({kappa} = 0.72-0.94). Considering the invasiveness of DSA and the minor difference in the diagnostic performance between 3D-DSA and TOF-MRA, the latter method should be the first-line modality for follow-up after aneurysm embolization. (orig.)

  2. Prospective Heart Tracking for Whole-heart Magnetic Resonance Angiography

    Science.gov (United States)

    Moghari, Mehdi H.; Geva, Tal; Powell, Andrew J.

    2015-01-01

    Purpose To develop a prospective respiratory-gating technique (Heart-NAV) for use with contrast-enhanced 3D inversion recovery (IR) whole-heart magnetic resonance angiography (MRA) acquisitions that directly tracks heart motion without creating image inflow artifact. Methods With Heart-NAV, 1 of the startup pulses for the whole-heart steady-state free precession MRA sequence is used to collect the centerline of k-space, and its 1-dimensional reconstruction is fed into the standard diaphragm-navigator (NAV) signal analysis process to prospectively gate and track respiratory-induced heart displacement. Ten healthy volunteers underwent non-contrast whole-heart MRA acquisitions using the conventional diaphragm-NAV and Heart-NAV with 5 and 10 mm acceptance windows in a 1.5T scanner. Five patients underwent contrast-enhanced IR whole-heart MRA using a diaphragm-NAV and Heart-NAV with a 5 mm acceptance window. Results For non-contrast whole-heart MRA with both the 5 and 10 mm acceptance windows, Heart-NAV yielded coronary artery vessel sharpness and subjective visual scores that were not significantly different than those using a conventional diaphragm-NAV. Scan time for Heart-NAV was 10% shorter (p<0.05). In patients undergoing contrast-enhanced IR whole-heart MRA, inflow artifact was seen with the diaphragm-NAV but not with Heart-NAV. Conclusion Compared to a conventional diaphragm-NAV, Heart-NAV achieves similar image quality in a slightly shorter scan time and eliminates inflow artifact. PMID:26843458

  3. Value of Single-Dose Contrast-Enhanced Magnetic Resonance Angiography Versus Intraarterial Digital Subtraction Angiography in Therapy Indications in Abdominal and Iliac Arteries

    International Nuclear Information System (INIS)

    Schaefer, Philipp J.; Schaefer, Fritz K. W.; Mueller-Huelsbeck, Stefan; Both, Markus; Heller, Martin; Jahnke, Thomas

    2007-01-01

    The objective of the study was to prove the value of single-dose contrast-enhanced magnetic resonance angiography [three-dimensional (3D) ceMRA] in abdominal and iliac arteries versus the reference standard intra-arterial digital subtraction angiography (i.a.DSA) when indicating a therapy. Patients suspected of having abdominal or iliac artery stenosis were included in this study. A positive vote of the local Ethics Committee was given. After written informed consent was obtained, 37 patients were enrolled, of which 34 were available for image evaluation. Both 3D ceMRA and i.a. DSA were performed for each patient. The dosage for 3D ceMRA was 0.1 mmol/kg body weight in a 1.5-T scanner with a phased-array coil. The parameters of the 3D-FLASH sequence were as follows: TR/TE 4.6/1.8 ms, effective thickness 3.5 mm, matrix 512 x 200, flip angle 30 o , field of view 420 mm, TA 23 s, coronal scan orientation. Totally, 476 vessel segments were evaluated for stenosis degree by two radiologists in a consensus fashion in a blinded read. For each patient, a therapy was proposed, if clinically indicated. Sensitivity, specificity, positive and negative predictive values, and accuracy for stenoses ≥50% were 68%, 92%, 44%, 97%, and 90%, respectively. In 13/34 patients, a discrepancy was found concerning therapy decisions based on MRA findings versus therapy decisions based on the reference standard DSA. The results showed that the used MRA imaging technique of abdominal and iliac arteries is not competitive to i.a. DSA, with a high rate of misinterpretation of the MRAs resulting in incorrect therapies

  4. Optimization of three-dimensional time-of-flight magnetic resonance angiography of the intracranial arteries

    International Nuclear Information System (INIS)

    Harada, Kuniaki; Honmou, Osamu; Odawara, Yoshihiro; Bando, Michio; Houkin, Kiyohiro

    2006-01-01

    The signal-to-noise ratio obtained from arteries in three-dimensional (3D) time-of-flight (TOF) magnetic resonance (MR) angiography is often too low to allow clinical diagnosis because the radiofrequency pulse decreases the magnetization of protons in the blood and suppresses the in-flow effect in the slab. The present study adjusted the position of the head coil to boost arterial signal intensity. Ten healthy volunteers, eight men and two women aged 24-78 years, underwent 3D TOF MR angiography of the intracranial arteries with the same standard GE transmit-receive birdcage head coil using both normal and half position (lower edge of the coil level with the mouth) methods. Our subjects were divided into Group 1 consisted of five relatively young volunteers aged 24-42 years (mean 31.2 years), and Group 2 consisted of five older volunteers aged 70-78 years (mean 73 years). The following four arteries were chosen for analysis: the internal carotid artery (ICA), the proximal middle cerebral artery segment (M 1 ), and the two distal middle cerebral artery segments (M 2 , M 3 ). The half position method increased the signal-to-noise ratio in the ICA, M 1 , M 2 , and M 3 by 15%, 25%, 36%, and 44%, respectively. In general, this method resulted in the generation of stronger signals in the M 2 and M 3 in younger subjects and in all arteries examined in older subjects. The half position method can provide better MR angiograms in certain brain regions of younger people, and in all brain regions in older patients. (author)

  5. Hemodynamic Change in Pulmonary Vein Stenosis after Radiofrequency Ablation: Assessment with Magnetic Resonance Angiography

    Energy Technology Data Exchange (ETDEWEB)

    Yun, Doyoung; Jung, Jung Im; Oh, Yong Seog; Youn, Ho Joong [Seoul St. Mary' s Hospital, College of Medicine, The Catholic University of Korea, Seoul (Korea, Republic of)

    2012-11-15

    We present a case of pulmonary vein (PV) stenosis after radio-frequency (RF) ablation, in which a hemodynamic change in the pulmonary artery was similar to that of congenital PV atresia on time-resolved contrast-enhanced magnetic resonance angiography (TR-MRA). A 48-year-old man underwent RF ablation due to atrial fibrillation. The patient subsequently complained of hemoptysis, dyspnea on exertion, and right chest pain. Right PV stenosis after catheter ablation was diagnosed through chest computed tomography and lung perfusion scan. Pulmonary TR-MRA revealed the pulmonary artery via systemic arterial collaterals and draining systemic collateral veins. On a velocity-encoded cine image, the flow direction of the right pulmonary artery was reversed in the diastolic phase and the left pulmonary artery demonstrated continuous forward flow throughout the cardiac cycle. These hemodynamic changes were similar to those seen in congenital unilateral PV atresia.

  6. MR angiography of the TMJ in asymptomatic volunteers

    International Nuclear Information System (INIS)

    Takagi, Ritsuo; Ohashi, Yasushi; Westesson, P.L.; Togashi, Hirosuke

    1998-01-01

    To evaluate the vascular anatomy of the temporomandibular joint (TMJ) and surrounding soft tissue non-invasively, we applied magnetic resonance (MR) angiography for delineating the arterial architecture around the TMJ. MR angiograms of the left and right TMJs in asymptomatic volunteers were obtained using 3D/Time-of-flight (TOF) (First Field Echo, TR/TE/FLIP=46 ms/6.8 ms/17 deg) with intravenous contrast. These MR angiograms were compared with experimental angiograms of human TMJ autopsy specimens in order to identify each of the branches of the arteries on the MR angiograms. This study enabled the depiction by MR angiography of arterial vessels around the TMJ region to some degree. In conclusion, MR angiography appears promising as a non-invasive tool to evaluate the vascular anatomy of the TMJ. (author)

  7. Catheter Angiography

    Medline Plus

    Full Text Available ... News Physician Resources Professions Site Index A-Z Catheter Angiography Catheter angiography uses a catheter, x-ray ... are the limitations of Catheter Angiography? What is Catheter Angiography? Angiography is a minimally invasive medical test ...

  8. An investigation of cerebral magnetic resonance angiography, 5

    International Nuclear Information System (INIS)

    Takeda, Sadanori; Sadamoto, Kazuhiko; Ohue, Shiro; Todo, Hirooki; Sakaki, Saburo.

    1992-01-01

    A number of studies of MR angiography (MRA) as a noninvasive screening method for vascular diseases have been reported recently. Almost all of them were investigated using high tesla magnets (1.5 tesla). We have been investigating three-dimensional MRA using a medium tesla (0.5 tesla) system (HITACHI G-50). The purpose of this study is to evaluate the usefulness of 3-D MRA for the screening of cerebral aneurysms. Twenty patients with 25 cerebral aneurysms were included in this study. The sizes of the aneurysms ranged from 2 to 35 mm. Twenty-three aneurysms were located on the anterior circulation, and 2 on the posterior circulation. MR angiography was performed with a gradient-echo sequence at a TR of 50 msec, a TE of 16 msec, and a flip angle of 25 degrees. The imaging volumes ranged in thickness from 48 to 64 mm, with 32 partitions. We used a sequence-subtraction technique composed of rephased and dephased sequences; it provides a good visualization of the main cerebral arteries. Cerebral aneurysms were detected on 3-D MRA in 23 lesions (92%). We consider that 0.5 tesla 3-D MRA could be useful for the screening of nonruptured aneurysms. (author)

  9. Magnetic resonance angiography in 12 patients with Wallenberg's syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, Masaki; Takahashi, Akira; Hashizume, Yoshio (Nagoya Univ. (Japan). Faculty of Medicine); Motegi, Yoshimasa; Furuse, Masahiro

    1992-11-01

    Magnetic resonance angiography (MRA) was performed in 12 patients with Wallenberg's syndrome (WS) in chronic stage to investigate the lesion of the vertebral artery (VA). The laterality of infarction in the medulla oblongata was confirmed with MRI; the right in four patients and the left in eight. In this study, time-of-flight MRA was evaluated. Coronal and OM sections in MRA were examined, because the former is useful to observe asymmetry and curve of the cervical VA, and the latter is useful to observe asymmetry and stenosis of the intracranial VA. In nine out of 12 patients, the ipsilateral VA was rather hypoplastic compared to the contralateral VA, and the flow of the hypoplastic VA stopped before and after entering the intracranial region. The contralateral VA of the hypoplastic cases showed curve in the neck in five patients and stenosis in the intracranial portion in one patient. A comparative study was conducted between vertebral angiogram (VAG) and MRA in four patients. Both VAG and MRA were useful in detecting hypoplasia and stoppage of the flow. It was considered that VA hypoplasia is frequently responsible for WS, and that MRA is useful in screening the vascular lesion as a non-invasive procedure to reveal changes of the bilateral VA. (author).

  10. Superselective pseudo-continuous arterial spin labeling angiography

    Energy Technology Data Exchange (ETDEWEB)

    Jensen-Kondering, Ulf [Department of Radiology and Neuroradiology, University Medical Center Schleswig-Holstein, Kiel (Germany); Lindner, Thomas, E-mail: thomas.lindner@uksh.de [Department of Radiology and Neuroradiology, University Medical Center Schleswig-Holstein, Kiel (Germany); Osch, Matthias J.P. van [C. J. Gorter Center for High Field MRI, Department of Radiology, Leiden University Medical Center, Leiden (Netherlands); Rohr, Axel; Jansen, Olav [Department of Radiology and Neuroradiology, University Medical Center Schleswig-Holstein, Kiel (Germany); Helle, Michael [Department of Radiology and Neuroradiology, University Medical Center Schleswig-Holstein, Kiel (Germany); Now with Philips GmbH Innovative Technologies, Research Laboratories, Hamburg (Germany)

    2015-09-15

    Highlights: • Superselective arterial spin labeling was capable of acquiring angiograms of individually selected arteries. • Image quality was similar compared with a routinely used time-of-flight angiography. • Superselective arterial spin labeling was utilized in patients with arterio-venous malformations and made it possible to visualize individual feeding vessels in a complete non-invasive way - Abstract: Purpose: To evaluate the utility of a novel non-contrast enhanced, vessel-selective magnetic resonance angiography (MRA) approach based on superselective pseudo-continuous arterial spin labeling (ASL) for the morphologic assessment of intracranial arteries when compared to a clinically used time-of-flight (TOF) MRA. Materials and methods: Three sets of selective ASL angiographies (right and left internal carotid artery, basilar artery) as well as one TOF data set were obtained from each of the five volunteers included in this study on a clinical 1.5T system. The depiction of arterial segments as well as their delineation was evaluated and independently analyzed by two radiologists. Additionally, the ASL angiography approach was performed in two patients suffering from arterio-venous malformations (AVM) in order to illustrate potential applications in a clinical setting. Results: In both angiography techniques, intracranial arteries and their segments (distal branches up to A5 segments of the anterior cerebral arteries, M8 segments of the middle cerebral arteries, and P5 segments of the posterior cerebral arteries) were continuously depicted with excellent inter-reader agreement (κ > 0.81). In AVM patients, reconstructed images of the TOF angiography presented similar information about the size and shape of the AVM as did superselective ASL angiography. In addition, the acquired ASL angiograms of selected vessels allowed assessing the blood supply of individually labeled arteries to the AVM which could also be confirmed by digital subtraction angiography

  11. Superselective pseudo-continuous arterial spin labeling angiography

    International Nuclear Information System (INIS)

    Jensen-Kondering, Ulf; Lindner, Thomas; Osch, Matthias J.P. van; Rohr, Axel; Jansen, Olav; Helle, Michael

    2015-01-01

    Highlights: • Superselective arterial spin labeling was capable of acquiring angiograms of individually selected arteries. • Image quality was similar compared with a routinely used time-of-flight angiography. • Superselective arterial spin labeling was utilized in patients with arterio-venous malformations and made it possible to visualize individual feeding vessels in a complete non-invasive way - Abstract: Purpose: To evaluate the utility of a novel non-contrast enhanced, vessel-selective magnetic resonance angiography (MRA) approach based on superselective pseudo-continuous arterial spin labeling (ASL) for the morphologic assessment of intracranial arteries when compared to a clinically used time-of-flight (TOF) MRA. Materials and methods: Three sets of selective ASL angiographies (right and left internal carotid artery, basilar artery) as well as one TOF data set were obtained from each of the five volunteers included in this study on a clinical 1.5T system. The depiction of arterial segments as well as their delineation was evaluated and independently analyzed by two radiologists. Additionally, the ASL angiography approach was performed in two patients suffering from arterio-venous malformations (AVM) in order to illustrate potential applications in a clinical setting. Results: In both angiography techniques, intracranial arteries and their segments (distal branches up to A5 segments of the anterior cerebral arteries, M8 segments of the middle cerebral arteries, and P5 segments of the posterior cerebral arteries) were continuously depicted with excellent inter-reader agreement (κ > 0.81). In AVM patients, reconstructed images of the TOF angiography presented similar information about the size and shape of the AVM as did superselective ASL angiography. In addition, the acquired ASL angiograms of selected vessels allowed assessing the blood supply of individually labeled arteries to the AVM which could also be confirmed by digital subtraction angiography

  12. Latest techniques in head and neck CT angiography

    International Nuclear Information System (INIS)

    Schuknecht, B.

    2004-01-01

    Continuous evolution of multi row CT is increasingly making CT angiography a viable imaging modality for assessment of the supraaortic and intracranial vessels as an anatomically and functionally coherent vascular system. Extended non-invasive examinations with reduced contrast volume have become feasible with the availability of 16 and 64 row MDCT scanners. Prerequisites to obtain high resolution CT angiographies of the head and neck vessels with superior detail include the administration of low contrast volume, high contrast density (400 mg I/ml) contrast media, adequate timing and data acquisition, optimal flow rate (4 ml/s) and saline flushing. Non-invasiveness, delineation of vessel calcification, virtual independence from hemodynamic conditions, and the ability to provide quantification without needing to correct for magnification are all attributes that favour CT angiography over digital subtraction angiography and to some extent even magnetic resonance angiography as an alternative non-invasive technique. CT angiography is established as a modality of choice for the assessment of patients with acute stroke and chronic steno-occlusive disease. CT angiography may indicate the presence of extra- or intracranial acute vessel occlusion and dissection, predisposing atherosclerotic steno-occlusive disease and thus indicate thrombo-embolism or local appositional thrombosis as the principle pathogenic factor. CT angiography is used to assess anatomy, and to depict the presence, location and extent of calcified and non-calcified plaque as a cause of high grade stenosis. Despite relatively limited sensitivity CT angiography is indicated for suspected or confirmed aneurysms that demand further verification of their presence, geometry, or relationship to parent artery branches and osseous anatomic landmarks. Low volume high density contrast media have substantially increased the ability of CT angiography to depict small aneurysms, small branches, and collateral vessels

  13. Clinical role of non-contrast magnetic resonance angiography for evaluation of renal artery stenosis

    International Nuclear Information System (INIS)

    Utsunomiya, Daisuke; Nomitsu, Yohei; Komeda, Yosuke; Okigawa, Takashi; Urata, Joji; Miyazaki, Mitsue; Yamashita, Yasuyuki

    2008-01-01

    The association between a gadolinium-based contrast material and nephrogenic systemic fibrosis has been discussed. The purpose of our study was to evaluate whether non-contrast enhanced magnetic resonance angiography (MRA) might provide sufficient information of renal artery stenosis. The non-contrast MRA of 26 patients with hypertension was retrospectively reviewed in the present study. The significant renal artery stenosis was visually evaluated by comparing non-contrast MRA with computed tomography or conventional angiographic finding. Difference of the intensities between the proximal and distal aorta was quantitatively evaluated. The sensitivity, specificity, positive predictive value and negative predictive value of non-contrast MRA in the evaluation of the renal artery stenosis was 78%, 91%, 64% and 96%, respectively. The distal abdominal aorta showed less signal intensity than the proximal aorta by 16.9±12.2%. Non-contrast MRA is a non-invasive and effective method that allows evaluation of the renal artery stenosis. (author)

  14. Toward comparability of coronary magnetic resonance angiography: proposal for a standardized quantitative assessment

    International Nuclear Information System (INIS)

    Dirksen, Martijn S.; Lamb, Hildo J.; Geest, Rob van der; Roos, Albert de

    2003-01-01

    A method is proposed for the quantitative assessment of coronary magnetic resonance angiography (MRA) acquisitions. The method is based on four parameters: signal-to-noise ratio (SNR); contrast-to-noise ratio (CNR); vessel length; and vessel-edge definition. A pig model (n=7) was used to illustrate the proposed quantitative analysis method. Three-dimensional gradient-echo coronary MRA was performed with and without exogenous contrast enhancement using a gadolinium-based blood-pool contrast agent (Vistarem, Guerbet, Aulnay-Sous-Bois, France). The acquired images could be well differentiated based on the four parameters. The SNR was calculated as 9.0±1.4 vs 10.4±2.1, the CNR as 6.2±0.8 vs 8.2±0.9, the vessel length as 48.2±11.6 vs 86.5±13.8 mm, and the vessel-edge definition as 4.9±1.5 vs 7.7±3.4. Different coronary MRA techniques can be evaluated objectively with the combined use of SNR, CNR, vessel length, and vessel-edge parameters. (orig.)

  15. Magnetic Resonance Imaging of Stroke

    NARCIS (Netherlands)

    Bouts, Mark. J. R. J.; Wu, O.; Dijkhuizen, R. M.

    2017-01-01

    Magnetic resonance imaging (MRI) provides a powerful (neuro)imaging modality for the diagnosis and outcome prediction after (acute) stroke. Since MRI allows noninvasive, longitudinal, and three-dimensional assessment of vessel occlusion (with magnetic resonance angiography (MRA)), tissue injury

  16. The value of magnetic resonance imaging for the detection of the bleeding source in non-traumatic intracerebral haemorrhages: a comparison with conventional digital subtraction angiography

    Energy Technology Data Exchange (ETDEWEB)

    Lummel, Nina; Lutz, Juergen; Brueckmann, Hartmut; Linn, Jennifer [University of Munich, Department of Neuroradiology, Munich (Germany)

    2012-07-15

    Conventional digital subtraction angiography (DSA) is currently regarded as the gold standard in detecting underlying vascular pathologies in patients with intracerebral haemorrhages (ICH). However, the use of magnetic resonance imaging (MRI) in the diagnostic workup of ICHs has considerably increased in recent years. Our aim was to evaluate the diagnostic accuracy and yield of MRI for the detection of the underlying aetiology in ICH patients. Sixty-seven consecutive patients with an acute ICH who underwent MRI (including magnetic resonance angiography (MRA) and DSA during their diagnostic workup) were included in the study. Magnetic resonance images were retrospectively analysed by two independent neuroradiologists to determine the localisation and cause of the ICH. DSA was used as a reference standard. In seven patients (10.4%), a DSA-positive vascular aetiology was present (one aneurysm, four arteriovenous malformations, one dural arteriovenous fistula and one vasculitis). All of these cases were correctly diagnosed by both readers on MRI. In addition, MRI revealed the following probable bleeding causes in 39 of the 60 DSA-negative patients: cerebral amyloid angiopathy (17), cavernoma (9), arterial hypertension (8), haemorrhagic transformation of an ischaemic infarction (3) and malignant brain tumour with secondary ICH (2). Performing MRI with MRA proved to be an accurate diagnostic tool in detecting vascular malformations in patients with ICH. In addition, MRI provided valuable information regarding DSA-negative ICH causes, and thus had a high diagnostic yield in ICH patients. (orig.)

  17. Role of high resolution contrast-enhanced magnetic resonance angiography (HR CeMRA) in management of arterial complications of the renal transplant

    International Nuclear Information System (INIS)

    Ismaeel, M. Maged; Abdel-Hamid, Azza

    2011-01-01

    Introduction: Transplant renal artery (RA) stenosis (TRAS) is the most frequent posttransplantation vascular complication. Contrast enhanced magnetic resonance (CeMRA) angiography has been established as the preferred imaging technique for the evaluation of TRAS because it does not require the use of iodinated contrast material and does not expose the patient to ionizing radiation. Digital subtraction angiography (DSA) is the gold standard in the evaluation of arterial tree of the renal allograft. Aim of the work: This study was carried out to assess the accuracy of CeMRA in the detection of arterial complications after renal transplantation. Patients and methods: Thirty renal transplant patients with suspected arterial complications in which both CeMRA and DSA were performed were included in the study. The HR CeMRA shows 93.7% sensitivity, 80% specificity, 88.2% positive predictive value, 88.9% negative predictive value and 88.5% accuracy. Conclusion: HR CeMRA is an accurate reliable tool in the assessment of arterial complications after renal transplantation. It may replace DSA as a diagnostic modality with reservation of interventional techniques for endovascular treatment of suitable cases.

  18. Role of high resolution contrast-enhanced magnetic resonance angiography (HR CeMRA) in management of arterial complications of the renal transplant

    Energy Technology Data Exchange (ETDEWEB)

    Ismaeel, M. Maged [Suez Canal University (Egypt); Abdel-Hamid, Azza, E-mail: azza4951@hotmail.com [Suez Canal University (Egypt)

    2011-08-15

    Introduction: Transplant renal artery (RA) stenosis (TRAS) is the most frequent posttransplantation vascular complication. Contrast enhanced magnetic resonance (CeMRA) angiography has been established as the preferred imaging technique for the evaluation of TRAS because it does not require the use of iodinated contrast material and does not expose the patient to ionizing radiation. Digital subtraction angiography (DSA) is the gold standard in the evaluation of arterial tree of the renal allograft. Aim of the work: This study was carried out to assess the accuracy of CeMRA in the detection of arterial complications after renal transplantation. Patients and methods: Thirty renal transplant patients with suspected arterial complications in which both CeMRA and DSA were performed were included in the study. The HR CeMRA shows 93.7% sensitivity, 80% specificity, 88.2% positive predictive value, 88.9% negative predictive value and 88.5% accuracy. Conclusion: HR CeMRA is an accurate reliable tool in the assessment of arterial complications after renal transplantation. It may replace DSA as a diagnostic modality with reservation of interventional techniques for endovascular treatment of suitable cases.

  19. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... work? Unlike conventional x-ray examinations and computed tomography (CT) scans, MRI does not utilize ionizing radiation. Instead, ... Angiography Magnetic Resonance, Functional (fMRI) - Brain Children's (Pediatric) CT (Computed Tomography) Magnetic Resonance Imaging (MRI) Safety Contrast Materials Children ...

  20. Angiography

    International Nuclear Information System (INIS)

    Grinnell, V.S.; Mehringer, C.M.; Hieshima, G.B.

    1987-01-01

    The history of angiography is short, with its centennial approaching. A very brief review of milestones begins with the discovery of x-rays in 1895. Only a few months later contrast agents too toxic for human use were being injected into cadavers, severed limbs, and animals. The next major developments came in the late 1970s when percutaneous translumbar aortography and cerebral angiography were described. Contrast agents were now less toxic, and clinically useful angiography was a reality. In 1953 a technique for percutaneous vascular catheterization which formed the basis of many catheterization techniques to follow was described. In the 1970s the development of less invasive diagnostic methods such as computed tomography and diagnostic ultrasound decreased the indications for angiography, but newer interventional techniques such as embolization therapy and angioplasty have taken up the slack. Angiography remains the most important way to demonstrate vascular diseases graphically. Specific techniques such as angioplasty and digital subtraction angiography will be dealt with in other chapters. The authors hope to provide an overview of major areas of angiographic utilization. The basic techniques of arterial puncture and catheterization have been well described elsewhere

  1. Computed tomography angiography in acute stroke (revisiting the 4Ps of imaging).

    Science.gov (United States)

    Varadharajan, Shriram; Saini, Jitender; Acharya, Ullas V; Gupta, Arun Kumar

    2016-02-01

    Imaging in acute stroke has traditionally focussed on the 4Ps-parenchyma, pipes, perfusion, and penumbra-and has increasingly relied upon advanced techniques including magnetic resonance imaging to evaluate such patients. However, as per European Magnetic Resonance Forum estimates, the availability of magnetic resonance imaging scanners for the general population in India (0.5 per million inhabitants) is quite low as compared to Europe (11 per million) and United States (35 per million), with most of them only present in urban cities. On the other hand, computed tomography (CT) is more widely available and has reduced scanning duration. Computed tomography angiography of cervical and intracranial vessels is relatively simpler to perform with extended coverage and can provide all pertinent information required in such patients. This imaging review will discuss relevant imaging findings on CT angiography in patients with acute ischemic stroke through illustrated cases. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. Collateral vessels in moyamoya disease : comparison of MR and MRA with conventional angiography

    International Nuclear Information System (INIS)

    Shim, Joo Eun; Yoon, Dae Young; Yi, Jeong Geun; Kim, Ho Chul; Choi, Chul Sun; Bae, Sang Hoon

    1998-01-01

    To determine the value of magnetic resonance imaging (MR) and magnetic resonance angiography (MRA) in assessing collateral vessels of moyamoya disease. Twenty-four patients with moyamoya disease who underwent MR, 3D TOF MRA, and conventional angiography participated in this study. Two radiologists working independently and with no knowledge of the angiographic findings, interpreted the MR and MRA images. To determine the presence of parenchymal and leptomeningeal collaterals (48 hemispheres) and transdural collaterals (38 hemispheres in 19 patients were depicted by angiography of the external carotid), the findings were compared with those of angiography. Parenchymal, leptomeningeal, and transdural collaterals were depicted by conventional angiography in 34 (71%), 32 (67%), and 11 (29%) hemispheres respectively. The sensitivity and specificity of MR/MRA for collateral vessels were 79.1/88.1 % for parenchymal collaterals, 72.1/88.1 % for leptomeningeal collaterals, and 0.1/18.1 % for transdural collaterals, respectively. Respective sensitivity and specificity of MR/MRA were 88.94/94.1% for leptomeningeal collaterals, and 18.93/55.1 % for transdural collaterals, when the prominent posterior cerebral and external carotid artery were regarded as secondary signs of leptomeningeal and transdural collateral vessels. In moyamoya disease, MR and MRA are useful imaging modalities for the assessment of collateral vessels. The prominent posterior cerebral artery and external carotid artery can be useful secondary signs of leptomeningeal and transdural collateral vessels. (author). 18 refs., 2 figs

  3. Angiography and interventional radiology of the kidneys; Angiographie und interventionelle Radiologie der Nieren

    Energy Technology Data Exchange (ETDEWEB)

    Hansmann, J.; Richter, G.M.; Hallscheidt, P.; Duex, M.; Noeldge, G.; Kaufmann, G.W. [Heidelberg Univ. (Germany). Abt. Radiodiagnostik

    1999-05-01

    For imaging of renal pathology a broad spectrum of radiologic diagnostic procedures are available which are, sometimes and particularly more recently, competing among each other in their diagnostic yield and relevance. For tumorous lesions ultrasound, computed tomography and magnetic resonance imaging are performed predominantly. Angiography is no longer required with the exception of highly selected cases and in some specific preoperative workup requirements. Until recently, catheter based digital subtraction angiography has been considered as gold standard. However, non-invasive techniques such as CT-angiography and MR-angiography are evolving parallel to their quantum leap of resolutions and readiness to use. Nevertheless, well accepted criteria for quality assessement of these new modalities are still lacking. More comparison studies are urgently warranted. Despite the availability of ultrashort pulse sequences applying the T1 relaxation reduction effect of gadolinium enhanced MR techniques overestimation of renal artery stenosis still poses a substantial problem. Renal intervention implies a variety of procedures such as plain angioplasty, stent placement, embolization of traumatic and both benign and malignant tumors. These methods have emerged over the last two decades from a more experimental nature to a fully accepted treatment option. When renal artery angioplasty is embedded in an aggressive approach including stenting as an adjunct for more complex cases, renal ostial lesions and a well organized follow-up regimen its therapeutic potential for treatment of renal insufficiency, malignant hypertension, for organ preservation bears a very high potential. Provided adequate periinterventional drug regimen restenosis rates may be as low as 10%. In highly selected cases capillary embolization might be used as an alternative to nephrectomy with a similar clinical outcome. Particularly the development of superselective small caliber embolization catheters

  4. Assessment of left ventricular volumes by magnetic resonance in comparison with radionuclide angiography, contrast angiography and echocardiography

    DEFF Research Database (Denmark)

    Møgelvang, J; Stokholm, K H; Saunamäki, K

    1992-01-01

    The present study shows that for assessment of LVEF, MRI and the standard methods seem to provide information of similar value. For absolute volume measurements, MRI and RNA are superior to single plane angiography and 2 DE using the modified Simpson-rule. The time consuming transversal MRI method...... quality, which is crucial especially in dilated ventricles containing stagnant or slowly moving blood....

  5. CT coronary angiography vs. invasive coronary angiography in CHD

    Directory of Open Access Journals (Sweden)

    Anja Hagen

    2012-04-01

    Full Text Available Scientific background: Various diagnostic tests including conventional invasive coronary angiography and non-invasive computed tomography (CT coronary angiography are used in the diagnosis of coronary heart disease (CHD. Research questions: The present report aims to evaluate the clinical efficacy, diagnostic accuracy, prognostic value cost-effectiveness as well as the ethical, social and legal implications of CT coronary angiography versus invasive coronary angiography in the diagnosis of CHD. Methods: A systematic literature search was conducted in electronic data bases (MEDLINE, EMBASE etc. in October 2010 and was completed with a manual search. The literature search was restricted to articles published from 2006 in German or English. Two independent reviewers were involved in the selection of the relevant publications. The medical evaluation was based on systematic reviews of diagnostic studies with invasive coronary angiography as the reference standard and on diagnostic studies with intracoronary pressure measurement as the reference standard. Study results were combined in a meta-analysis with 95 % confidence intervals (CI. Additionally, data on radiation doses from current non-systematic reviews were taken into account. A health economic evaluation was performed by modelling from the social perspective with clinical assumptions derived from the meta-analysis and economic assumptions derived from contemporary German sources. Data on special indications (bypass or in-stent-restenosis were not included in the evaluation. Only data obtained using CT scanners with at least 64 slices were considered. Results: No studies were found regarding the clinical efficacy or prognostic value of CT coronary angiography versus conventional invasive coronary angiography in the diagnosis of CHD. Overall, 15 systematic reviews with data from 44 diagnostic studies using invasive coronary angiography as the reference standard (identification of obstructive

  6. MR coronary angiography with breath-hold targeted volumes: preliminary clinical results

    NARCIS (Netherlands)

    R.J.M. van Geuns (Robert Jan); P.A. Wielopolski (Piotr); H.G. de Bruin (Hein); B.J.W.M. Rensing (Benno); M. Hulshoff (Maarten); P.M.A. van Ooijen (Peter); P.J. de Feyter (Pim); M. Oudkerk (Matthijs)

    2000-01-01

    textabstractPURPOSE: To assess the clinical value of a magnetic resonance (MR) coronary angiography strategy involving a small targeted volume to image one coronary segment in a single breath hold for the detection of greater than 50% stenosis. MATERIALS AND METHODS:

  7. A quantitative study of ramped radio frequency, magnetization transfer, and slab thickness in three-dimensional time-of-flight magnetic resonance angiography in a patient population.

    Science.gov (United States)

    Goodrich, K C; Blatter, D D; Parker, D L; Du, Y P; Meyer, K J; Bernstein, M A

    1996-06-01

    The authors compare the effectiveness of various magnetic resonance (MR) angiography acquisition strategies in enhancing the visibility of small intracranial vessels. Blood vessel contrast-to-noise ratio (CNR) in time-of-flight MR angiography was studied as a function of vessel size and several selectable imaging parameters. Contrast-to-noise measurements were made on 257 vessel segments ranging in size from 0.3 mm to 4.2 mm in patients who recently had undergone intraarterial cerebral angiography. Imaging parameters studied included magnetization transfer, spatially variable radio frequency (RF) pulse profile (ramped RF), and imaging slab thickness. The combination of thin slabs (16 slices/slab), ramped RF, and magnetization transfer resulted in the highest CNR for all but the smallest vessel sizes. The smallest vessels (slab (64 slices/slab) with ramped RF and magnetization transfer. Magnetization transfer always improved vessel CNR, but the improvement diminished as the slab thickness was reduced. The CNR increased with a decrease in slab thickness for all but the smallest vessel sizes. Overall, the results provide a quantitative demonstration that inflow enhancement of blood is reduced for small vessels. Thus, whereas magnetization transfer is important at all vessel sizes, it becomes the primary factor in improving the visibility of the smallest vessels.

  8. Compact 6 dB Two-Color Continuous Variable Entangled Source Based on a Single Ring Optical Resonator

    Directory of Open Access Journals (Sweden)

    Ning Wang

    2018-02-01

    Full Text Available Continuous-variable entangled optical beams at the degenerate wavelength of 0.8 μm or 1.5 μm have been investigated extensively, but separately. The two-color entangled states of these two useful wavelengths, with sufficiently high degrees of entanglement, still lag behind. In this work, we analyze the various limiting factors that affect the entanglement degree. On the basis of this, we successfully achieve 6 dB of two-color quadrature entangled light beams by improving the escape efficiency of the nondegenerate optical amplifier, the stability of the phase-locking servo system, and the detection efficiency. Our entangled source is constructed only from a single ring optical resonator, and thus is highly compact, which is suitable for applications in long-distance quantum communication networks.

  9. Nested trampoline resonators for optomechanics

    Science.gov (United States)

    Weaver, M. J.; Pepper, B.; Luna, F.; Buters, F. M.; Eerkens, H. J.; Welker, G.; Perock, B.; Heeck, K.; de Man, S.; Bouwmeester, D.

    2016-01-01

    Two major challenges in the development of optomechanical devices are achieving a low mechanical and optical loss rate and vibration isolation from the environment. We address both issues by fabricating trampoline resonators made from low pressure chemical vapor deposition Si3N4 with a distributed Bragg reflector mirror. We design a nested double resonator structure with 80 dB of mechanical isolation from the mounting surface at the inner resonator frequency, and we demonstrate up to 45 dB of isolation at lower frequencies in agreement with the design. We reliably fabricate devices with mechanical quality factors of around 400 000 at room temperature. In addition, these devices were used to form optical cavities with finesse up to 181 000 ± 1000. These promising parameters will enable experiments in the quantum regime with macroscopic mechanical resonators.

  10. Ultra-widefield fluorescein angiography reveals retinal phlebitis in Susac's syndrome.

    Science.gov (United States)

    Klufas, Michael A; Dinkin, Marc J; Bhaleeya, Swetangi D; Chapman, Kristin O; Riley, Claire S; Kiss, Szilárd

    2014-01-01

    A 23-year-old woman with history of headaches and auditory changes presented with acute-onset visual field loss in the right eye. The combination of multiple retinal branch artery occlusions of the right eye on funduscopic examination, characteristic white matter lesions in the corpus callosum on magnetic resonance imaging, and hearing loss on audiometric testing led to a diagnosis of Susac's syndrome. Ultra-widefield fluorescein angiography revealed involvement of the retinal veins, which has not been previously reported with this condition. Additionally, ultra-widefield indocyanine green angiography demonstrated changes in the choroidal circulation, which are controversial in this syndrome. Copyright 2014, SLACK Incorporated.

  11. Antidiabetic and Antiobesity Effects of Artemether in db/db Mice

    Directory of Open Access Journals (Sweden)

    Yu Guo

    2018-01-01

    Full Text Available This study is designed to investigate the effect of artemether on type 2 diabetic db/db mice. The experiments consisted of three groups: normal control (NC, db/+, 1% methylcellulose, intragastric administration, diabetic control (DM, db/db, 1% methylcellulose, intragastric administration, and artemether treated (artemether, db/db, 200 mg/kg of artemether, intragastric administration. The treatment lasted for two weeks. The food intake, body weight, and fasting blood glucose of mice were measured every three days. At the start and end of the experiment, the intraperitoneal glucose tolerance test (IPGTT and insulin tolerance test (IPITT were performed. We determined the serum insulin and glucagon levels by ELISA kits and calculated insulin resistance index (HOME-IR. HE staining was used to observe the morphologies of pancreas and liver in mice. The damage of pancreatic beta cells was evaluated by TUNEL staining and immunofluorescence. We found the following: (1 compared with the DM group, the food intake and weight increase rate of artemether group significantly reduced (P<0.05; (2 compared with pretreatment, artemether significantly reduced the fasting blood glucose levels, and the areas under the curves (AUCs of IPGTT were decreased significantly, increasing the tolerance to glucose of db/db mice. (P<0.05; (3 artemether improved hyperinsulinemia and decreased the AUCs of IPITT and HOME-IR, increasing the insulin sensitivity of db/db mice. (4 Artemether significantly ameliorated islet vacuolar degeneration and hepatic steatosis in db/db mice. (5 Artemether reduced the apoptosis of pancreatic beta cells and increased insulin secretion in db/db mice compared with DM group (P<0.05. Our results indicated that artemether significantly improved glucose homeostasis and insulin resistance and had the potential activity to prevent obesity, reduced the severity of fatty liver, and protected pancreatic beta cells, promising to treat type 2 diabetes.

  12. MR coronary angiography with breath-hold targeted volumes : Preliminary clinical results

    NARCIS (Netherlands)

    van Geuns, R J; Wielopolski, P A; de Bruin, Hein G.; Rensing, B J; Hulshoff, Marc; van Ooijen, P M; de Feyter, P J; Oudkerk, M

    2000-01-01

    PURPOSE: To assess the clinical value of a magnetic resonance (MR) coronary angiography strategy involving a small targeted volume to image one coronary segment in a single breath hold for the detection of greater than 50% stenosis. MATERIALS AND METHODS: Thirty-eight patients referred for elective

  13. Multidetector-row CT angiography of hepatic artery: comparison with conventional angiography

    International Nuclear Information System (INIS)

    Kim, Jin Woong; Jeong, Yong Yeon; Yoon, Woong; Kim, Jae Kyu; Park, Jin Gyoon; Seo, Jeong Jin; Kang, Heoung Keun

    2003-01-01

    To determine the usefulness of three-dimensional CT angiography using multidetector-row CT (MD-CT) for delineating the arterial anatomy of the liver. Hepatic arterial three-dimensional CT angiography was performed using MDCT (lightspeed Qx/I; GE medical systems, milwaukee, Wis., U.S.A.) in 45 patients with HCC undergoing conventional angiography for transcatheter hepatic arterial chemoembolization. The scanning parameters during the early arterial phase were 2.5 mm slice thickness, 7.5 mm rotation of table speed, and a pitch of 3. Images were obtained by one radiologist using maximum intensity projection from axial CT images obtained during the early arterial phase. Two radiologists blinded to the findings of conventional angiography independently evaluated the hepatic arterial anatomy and the quality of the images obtained. Compared with conventional angiography, reader A correctly evaluated the hepatic arterial anatomy depicted at three-dimensional CT angiography. Reader B's evaluation was correct in 40 of 45 patients. Interobserver agreement was good (kappa value, 0.73), and both readers assessed the quality of three-dimensional CT angiography as excellent. Three-dimensional CT angiography using MDCT was accurate for delineating the arterial anatomy of the liver, and interobserver agreement was good. The modality may provide, prior to conventional angiography, valuable information regrading a patient's hepatic arterial anatomy

  14. Clinical application of pelvic MR angiography for gynecologic diseases

    Energy Technology Data Exchange (ETDEWEB)

    Ohnishi, Takeshi [Saint Marianna Univ., Kawasaki, Kanagawa (Japan). School of Medicine

    1996-08-01

    Magnetic resonance (MR) imaging is the second most important method next to the ultrasound for the diagnosis of gynecological disorders. MR angiography provides a new noninvasive method for evaluating vascular occlusive disease of the lower extremities and the branches of abdominal aorta. To our knowledge, no determinant of efficacy of MR angiography and images of gynecological diseases have yet been made. Maximum intensity projection image was obtained from the data set by the three dimensional contrast enhanced MR angiography (3D-CE MRA) with newly designed fat suppression method. MR angiogram reveals well visualization of lower abdominal aorta and its branches. Furthermore, uterine arteries were identified in 49.3% of the cases, branching from the internal iliac artery. Leiomyoma of the uterus showed an enhanced uterus in 53.7% of the eases. All cases of endometriosis demonstrated a homogeneous, high signal intensity being a specific finding. In conclusion, maximum intensity projection image of pelvis showed a good visualization of the lower abdominal aorta and its branches. Uterine artery and, in a few cases, ovarian artery can be demonstrated on MR angiography. All cases of endometriosis showed a significant, high signal intensity. This technique is noninvasive and be a supplementary method for diagnosis and follow up of vasculature of gynecological disorders. (author)

  15. Clinical application of pelvic MR angiography for gynecologic diseases

    International Nuclear Information System (INIS)

    Ohnishi, Takeshi

    1996-01-01

    Magnetic resonance (MR) imaging is the second most important method next to the ultrasound for the diagnosis of gynecological disorders. MR angiography provides a new noninvasive method for evaluating vascular occlusive disease of the lower extremities and the branches of abdominal aorta. To our knowledge, no determinant of efficacy of MR angiography and images of gynecological diseases have yet been made. Maximum intensity projection image was obtained from the data set by the three dimensional contrast enhanced MR angiography (3D-CE MRA) with newly designed fat suppression method. MR angiogram reveals well visualization of lower abdominal aorta and its branches. Furthermore, uterine arteries were identified in 49.3% of the cases, branching from the internal iliac artery. Leiomyoma of the uterus showed an enhanced uterus in 53.7% of the eases. All cases of endometriosis demonstrated a homogeneous, high signal intensity being a specific finding. In conclusion, maximum intensity projection image of pelvis showed a good visualization of the lower abdominal aorta and its branches. Uterine artery and, in a few cases, ovarian artery can be demonstrated on MR angiography. All cases of endometriosis showed a significant, high signal intensity. This technique is noninvasive and be a supplementary method for diagnosis and follow up of vasculature of gynecological disorders. (author)

  16. Magnetic resonance angiography of the neck vessels: technique and anatomy

    International Nuclear Information System (INIS)

    Carriero, A.; Salute, L.

    1990-01-01

    The authors identified the standard projections for studying neck vessels with magnetic resonance angiography. Sixty volunteers underwent angio-MR of the arterial neck vessels with FISP 3D FT sequences obtained on the coronal and sagittal planes. The gradient-echo sequence (FISP 3D FT) was acquired with TR=0.04-0.08 s and TE=15 ms, with 25 grade flip angle. Single excitated slices of thickness ranging from 1-2 mm were included in the acquisition volume. Theses sequences were subsequently processed by the maximum intensity projection method. Two radiologist examined our results to choose the optimal projections. We used a semi-quantitative scale which allowed us to distinguish 3 different diagnostic levels for each projection: well-visualized vessels, poorly-visualized, and non-visualized ones. For each section axial rotations were performed ranging from 0 grade to 180 grade, with 15 grade i ntervals. On the coronal plane, rotations from 45 grade to 45 grade were the optimal ones to visualize the studied vessels. The 0 grade- 15 grade- 30 grade- 45 grade- 135 grade- 165 grade- 180 grade projections allowed the common carotids to be clearly demonstrated together with the verterbal arteries. The other projections appeared to be useless for diagnostic purposes. On the saggittal plane, rotations from 60 grade to 120 grade were the optimal ones. The 90 grade projection allowed the demonstration of all the big arterial vessel of the neck, including carotid bifurcation and internal and external carotids. The assessment of the optimal diagnostic projections for angio-MR of the neck vessels is helpful to reduce post-processing time. As a matter of fact, the immediate visualization, during the examination, of the standard projections allows further acquisitions to be obtained- if needed- to try to solve specific diagnostic doubts

  17. Aortic Volumetry at Contrast-Enhanced Magnetic Resonance Angiography: Feasibility as a Sensitive Method for Monitoring Bicuspid Aortic Valve Aortopathy.

    Science.gov (United States)

    Trinh, Brian; Dubin, Iram; Rahman, Ozair; Ferreira Botelho, Marcos P; Naro, Nicholas; Carr, James C; Collins, Jeremy D; Barker, Alex J

    2017-04-01

    Bicuspid aortic valve patients can develop thoracic aortic aneurysms and therefore require serial imaging to monitor aortic growth. This study investigates the reliability of contrast-enhanced magnetic resonance angiography (CEMRA) volumetry compared with 2-dimensional diameter measurements to identify thoracic aortic aneurysm growth. A retrospective, institutional review board-approved, and Health Insurance Portability and Accountability Act-compliant study was conducted on 20 bicuspid aortic valve patients (45 ± 8.9 years, 20% women) who underwent serial CEMRA with a minimum imaging follow-up of 11 months. Magnetic resonance imaging was performed at 1.5 T with electrocardiogram-gated, time-resolved CEMRA. Independent observers measured the diameter at the sinuses of Valsalva (SOVs) and mid ascending aorta (MAA) as well as ascending aorta volume between the aortic valve annulus and innominate branch. Intraobserver/interobserver coefficient of variation (COV) and intraclass correlation coefficient (ICC) were computed to assess reliability. Growth rates were calculated and assessed by Student t test (P volumetry. Three-dimensional CEMRA volumetry exhibited a larger effect when examining percentage growth, a better ICC, and a marginally lower COV. Volumetry may be more sensitive to growth and possibly less affected by error than diameter measurements.

  18. Retrospective analysis of the prevalence of asymptomatic cerebral aneurysm in 4518 patients undergoing magnetic resonance angiography. When does cerebral aneurysm develop?

    International Nuclear Information System (INIS)

    Horikoshi, Toru; Yamagata, Zentaro; Nukui, Hideaki; Akiyama, Iwao

    2002-01-01

    The natural history of cerebral aneurysms was investigated by measuring the prevalence of incidentally found unruptured aneurysms in the general population and evaluating the characteristics including risk factors. 'De novo' formation of aneurysm was also demographically estimated. The prevalence of incidental aneurysm was evaluated among 4518 patients who underwent magnetic resonance (MR) angiography for various reasons in a neurosurgical institute. Double the number of patients were randomly selected from the remaining patients without aneurysm as the Control group so that sex and age group were matched to the Aneurysm group. One hundred twenty seven patients (2.8%) had diagnoses of aneurysm. The prevalence of asymptomatic aneurysm among middle-aged and elderly patients were predominant in women and increased with age in both sexes. Patients with aneurysms had significantly more hypertension and family history of subarachnoid hemorrhage compared to the controls. The prevalence was markedly increased in the 8th decade in men and the 7th decade in women, and new aneurysms seemed to develop predominantly around these decades. Cerebral aneurysms become detectable on MR angiography in the middle or later decades, and women tend to develop aneurysm earlier than men. Hypertension and family history of subarachnoid hemorrhage are probably risk factors for the development of aneurysm. (author)

  19. Peripheral MR Angiography of Klippel-Trenaunay Syndrome

    International Nuclear Information System (INIS)

    Fontana, Alessandro; Olivetti, Lucio

    2004-01-01

    Klippel-Trenaunay syndrome (KTS) is a rare congenital vascular disease of unknown etiology that affects one or more limbs. It is characterized clinically by three physical findings (the so-called triad): port-wine stain hemangioma, hypertrophy of the bony and/or soft tissue, and varicose veins. A review of the medical literature in 1999 revealed about 1,000 case studies. We present here the case of a patient with clinical diagnosis of KTS studied using peripheral magnetic resonance angiography

  20. The Impact of Injector-Based Contrast Agent Administration on Bolus Shape and Magnetic Resonance Angiography Image Quality.

    Science.gov (United States)

    Jost, Gregor; Endrikat, Jan; Pietsch, Hubertus

    2017-01-01

    To compare injector-based contrast agent (CA) administration with hand injection in magnetic resonance angiography (MRA). Gadobutrol was administered in 6 minipigs with 3 protocols: (a) hand injection (one senior technician), (b) hand injection (6 less-experienced technicians), and (c) power injector administration. The arterial bolus shape was quantified by test bolus measurements. A head and neck MRA was performed for quantitative and qualitative comparison of signal enhancement. A significantly shorter time to peak was observed for protocol C, whereas no significant differences between protocols were found for peak height and bolus width. However, for protocol C, these parameters showed a much lower variation. The MRA revealed a significantly higher signal-to-noise ratio for injector-based administration. A superimposed strong contrast of the jugular vein was found in 50% of the hand injections. Injector-based CA administration results in a more standardized bolus shape, a higher vascular contrast, and a more robust visualization of target vessels.

  1. The Impact of Injector-Based Contrast Agent Administration on Bolus Shape and Magnetic Resonance Angiography Image Quality

    Directory of Open Access Journals (Sweden)

    Gregor Jost

    2017-04-01

    Full Text Available Objective: To compare injector-based contrast agent (CA administration with hand injection in magnetic resonance angiography (MRA. Methods: Gadobutrol was administered in 6 minipigs with 3 protocols: (a hand injection (one senior technician, (b hand injection (6 less-experienced technicians, and (c power injector administration. The arterial bolus shape was quantified by test bolus measurements. A head and neck MRA was performed for quantitative and qualitative comparison of signal enhancement. Results: A significantly shorter time to peak was observed for protocol C, whereas no significant differences between protocols were found for peak height and bolus width. However, for protocol C, these parameters showed a much lower variation. The MRA revealed a significantly higher signal-to-noise ratio for injector-based administration. A superimposed strong contrast of the jugular vein was found in 50% of the hand injections. Conclusions: Injector-based CA administration results in a more standardized bolus shape, a higher vascular contrast, and a more robust visualization of target vessels.

  2. Supra-aortic low-dose contrast-enhanced time-resolved magnetic resonance (MR) angiography at 3 T: comparison with time-of-flight MR angiography and high-resolution contrast-enhanced MR angiography.

    Science.gov (United States)

    Lee, Youn-Joo; Kim, Bum-soo; Koo, Ja-Sung; Kim, Bom-Yi; Jang, Jinhee; Choi, Hyun Seok; Jung, So-Lyung; Ahn, Kook-Jin

    2015-06-01

    Low-dose, time-resolved, contrast-enhanced, magnetic resonance angiography (TR-CEMRA) has been described previously; however, a comparative study between low dose TR-CEMRA and time-of-flight MRA (TOF-MRA) in the diagnosis of supra-aortic arterial stenosis has not yet been published. To demonstrate the feasibility and effectiveness of low-dose TR-CEMRA compared with TOF-MRA, using high-resolution contrast-enhanced MRA (HR-CEMRA) as the reference standard. This prospective study consisted of 30 consecutive patients. All patients underwent TOF-MRA of the neck and circle of Willis and supra-aortic HR-CEMRA, followed by supra-aortic low-dose TR-CEMRA. Gadoterate meglumine (Gd-DOTA, Dotarem(®), Guerbet, Roissy CdG Cedex, France) was injected at a dose of 0.1 mmol/kg for HR-CEMRA, followed by a 0.03 mmol/kg bolus for low-dose TR-CEMRA. Three readers evaluated the assessibility and image quality, and then two readers classified each stenosis into the following categories: normal (0-30%), mild stenosis (31-50%), moderate (51-70%), severe (71-99%), and occlusion. TR-CEMRA and HR-CEMRA showed a greater number of assessable arterial segments than TOF-MRA (P supra-aortic arterial stenosis, and could be more useful option than TOF-MRA. © The Foundation Acta Radiologica 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  3. Magnetic resonance angiography of peripheral arteries of the hand and its clinical usefulness

    International Nuclear Information System (INIS)

    Arikawa, Kouzou

    1996-01-01

    We established requirements for display of peripheral arteries and veins of the hand on magnetic resonance angiography (MRA) in normal adults. We performed MRA in 20 normal adult volunteers and 3 patients using the same method and parameters and obtained useful clinical examinations. Few studies have evaluated the use of MRA in the hand, especially for peripheral arteries and veins, because of problems of vessel diameter, velocity blood flow, and computer memory capacity. The diagnostic accuracy of MRA is largely dependent on the MR equipment, MR technique, ray-tracing technique, film reading system, and the skill of the MRA film reader. Because MRA methods are not standardized, optimal methods must be determined that produce the accurate information needed for diagnosis of disease. In 20 normal adults, the following MRA parameters allowed us to consistently visualize the peripheral arteries and veins: flip angle, 90deg; TR, 35; TE, 16; slice thickness, 2 mm; FOV, 170; NSA, 2; acquisition matrix, 141 x 256; and room temperature, 22degC. We were able to obtain clear MRA images by the multiple slide slice method, which corrects a weakness of usual methods of display. Results of MRA examinations with our methods and parameters in 20 normal adult volunteers and 3 patients suggest that MRA is safe and useful for clinical examination of the hand. (author)

  4. Magnetic resonance angiography with ultrashort echo times reduces the artefact of aneurysm clips

    International Nuclear Information System (INIS)

    Goenner, F.; Heid, O.; Remonda, L.; Schroth, G.; Loevblad, K.O.; Guzman, R.; Barth, A.

    2002-01-01

    We evaluated the ability of an ultrashort echo time (TE) three-dimensional (3D) time-of-flight (TOF) magnetic resonance angiography (MRA) sequence to reduce the metal artefact of intracranial aneurysm clips and to display adjacent cerebral arteries. In five patients (aged 8-72 years) treated with Elgiloy or Phynox aneurysm clips we prospectively performed a conventional (TE 6.0 ms) and a new ultrashort TE (TE 2.4 ms) 3D TOF MRA. We compared the diameter of the clip-induced susceptibility artefact and the detectability of flow in adjacent vessels. The mean artefact diameter was 22.3±6.4 mm (range 14-38 mm) with the ultrashort TE and 27.7±6.4 mm (range 19-45 mm) with the conventional MRA (P<0.0001). This corresponded to a diameter reduction of 19.5±9.2%. More parts of adjacent vessels were detected, but with less intense flow signal. The aneurysm dome and neck remained within the area of signal loss and were therefore not displayed. Ultrashort TE MRA is a noninvasive and fast method for improving detection of vessels adjacent to clipped intracranial aneurysms, by reducing clip-induced susceptibility artefact. The method cannot, however, be used to show remnants of the aneurysm neck or sac as a result of imperfect clipping. (orig.)

  5. Imaging of the digital arteries: Digital subtraction angiography versus conventional angiography

    International Nuclear Information System (INIS)

    Menanteau, B.P.; Treutenaere, J.M.; Marcus, C.; Ladam, V.; Gausserand, F.

    1986-01-01

    The authors report their experience with the use of digital subtraction angiography (DSA) and conventional angiography of the hand. Of the 95 patients in the study group, 80 underwent conventional angiography and 15 underwent DSA. They analyzed the studies with regard to the type and amount of contrast agent used, the number of radiographs needed, and the diagnostic quality of the images. Conventional angiography often requires general anesthesia, magnification, and pharmaco-angiographic techniques to improve the image-based diagnosis. In comparison with conventional angiography, intraarterial DSA is characterized by improved contrast sensitivity and inferior spatial resolution. However, DSA provides images as acceptable as those of conventional angiography. Smaller catheters can be used, and the examination is performed under local anesthesia. The authors conclude that intraarterial DSA is now the technique of choice for examining patients with chronic ischemia of the hand

  6. MR-angiography

    International Nuclear Information System (INIS)

    Seiderer, M.

    1989-01-01

    Three categories of MRI techniques for vascular imaging are discussed: 2d-angiography using rephasing and dephasing pulse sequences and slice selective imaging; 3d-angiography using rehpasing and dephasing pulse sequences and fas 3d-imaging techniques; 3d-angiography using signal intensity modulation caused by pre- and post-contrast data acquisition (e.g. Gadolinium-DTPA) in combination with fast 3d-imaging (only one type of pulse sequence). (H.W.). 6 figs

  7. Rapid time-resolved magnetic resonance angiography via a multiecho radial trajectory and GraDeS reconstruction.

    Science.gov (United States)

    Lee, Gregory R; Seiberlich, Nicole; Sunshine, Jeffrey L; Carroll, Timothy J; Griswold, Mark A

    2013-02-01

    Contrast-enhanced magnetic resonance angiography is challenging due to the need for both high spatial and temporal resolution. A multishot trajectory composed of pseudo-random rotations of a single multiecho radial readout was developed. The trajectory is designed to give incoherent aliasing artifacts and a relatively uniform distribution of projections over all time scales. A field map (computed from the same data set) is used to avoid signal dropout in regions of substantial field inhomogeneity. A compressed sensing reconstruction using the GraDeS algorithm was used. Whole brain angiograms were reconstructed at 1-mm isotropic resolution and a 1.1-s frame rate (corresponding to an acceleration factor > 100). The only parameter which must be chosen is the number of iterations of the GraDeS algorithm. A larger number of iterations improves the temporal behavior at cost of decreased image signal-to-noise ratio. The resulting images provide a good depiction of the cerebral vasculature and have excellent arterial/venous separation. Copyright © 2012 Wiley Periodicals, Inc.

  8. High-resolution 3D Magnetic Resonance angiography in the evaluation of neck vessels and intracranial circulation

    International Nuclear Information System (INIS)

    Villa, A.; Di Guglielmo, L.; Campani, R.; Nicolato, A.; D'Amato, M.; Rodriguez y Balena, R.

    1991-01-01

    Magnetic Resonance Angiography (MRA) is a modern vascular imaging technique which allows the non-invasive and direct imaging of vessels. The authors aimed at evaluating the diagnostic accuracy of MRA in the study of pathologic conditions in the neck and intracranial vessels; spatial resolution of the technique was also investigated. Twenty-four healthy volunteers and 82 patients suffering from various diseases of the head and neck vessels were included in the study. First of all, MRA capabilities ware investigated in visualizing normal vessels of both neck and intracranial circle. The diagnostic accuracy of the method was then evaluated in the study of vascular diseases, and the results compared with conventional/digital angiographic findings. The comparison demonstrated how stenoses and atherosclerotic plaques tend to be overestimated by MRA because of technical artifacts inherent to the technique itself, whereas vascular ulcerations and aneurysms are frequently underestimated. However, this data was steady and therefore evaluable- the exact knowledge of the artifacts making diagnosis reliable. The diagnostic and technical problems relative to the various vascular diseases are discussed. Finally, several hypotheses of diagnostic iter are suggested

  9. Pulmonary embolism and pelvic-lower limb deep venous thrombosis: initial experience with magnetic resonance angiography

    International Nuclear Information System (INIS)

    Jiang Tao; Qiu Chuanya; Jiang Hua

    2004-01-01

    Objective: To evaluate the usefulness of combined three-dimensional (3D) and two-dimensional (2D) contrast enhanced magnetic resonance angiography (CE-MRA) for checking the thrombus embolism of different positions within single examination on the pulmonary artery and pelvic-lower limb deep veins. Methods: Fifteen patients with suspected pulmonary embolism and pelvic-lower limb deep venous thrombosis (DVT) were evaluate with combined 3D MRA and 2D CE-MRA. 3D spoiled gradient-recalled-echo bolus chase MR angiograms were obtained in four stations from the pulmonary artery to the ankle. Thereafter, 3D CE MRA was reversely scanned from the ankle to the pelvic. 2D contrast-enhanced MRI was obtained in pelvis, thigh, and calf. Pulmonary CT angiography (CTA) and/or DSA were performed in 15 patients, and duplex ultrasonography of lower-limb vein was performed in 12 patients. Results: Of the 15 cases, acceptable imaging of pulmonary vessel was acquired with 3D CE-MRA in 12 cases. The signal intensity was lower in the deep iliac vein and lower extremities than that in the artery, but vein frame was distinct after post processing. The artery and deep vein were clearly revealed with contrast enhanced FSPGR sequence in 15 cases. 3D CD-MRA imaging disclosed pulmonary embolism in fourteen patients and pelvis-lower limb DVT with multi-place involvement in nine patients. 2D contrast-enhanced MR imaging proved DVT in pelvis-lower limb. 2D contrast-enhanced FSPGR sequence was a complementation of 3D CE-MRA and it had larger scan field. Thrombus presented as low signals and eccentral or intraluminal filling defect. Local caliber of vein thrombus in 6 cases was evidently broadened. Conclusion: Within only one MR examination procedure, it is capable of examining the pulmonary embolism and DVT of pelvis-lower limb with combined 3D MRA and 2D contrast enhanced MR. The results are promising as a non-invasion 'on-stop shopping' tool in the evaluation of thromboembolic disease

  10. Microembolism after cerebral angiography

    International Nuclear Information System (INIS)

    Manaka, Hiroshi; Sakai, Hideki; Nagata, Izumi

    2000-01-01

    Acute microemboli are detected more precisely with the recently developed diffusion-weighted MR imaging (DWI). We happened to obtain 24 DWIs after 350 diagnostic cerebral angiographies in 1999. DWIs after cerebral angiographies showed bright lesions in 7 patients (28%), of whom 6 had no neurological symptoms after cerebral angiography. Seven of the 24 patients had risk factors for arteriosclerosis. Only one patient had embolic events due to angiography. Microemboli related to cerebral angiographies are inevitable in some patients. Most are silent, however, we should investigate the cause of microemboli and should make cerebral angiography safer. (author)

  11. Impaired Muscle Regeneration in Ob/ob and Db/db Mice

    Directory of Open Access Journals (Sweden)

    Mai-Huong Nguyen

    2011-01-01

    Full Text Available In obesity and type 2 diabetes, efficient skeletal muscle repair following injury may be required, not only for restoring muscle structure and function, but also for maintaining exercise capacity and insulin sensitivity. The hypothesis of this study was that muscle regeneration would be impaired in ob/ob and db/db mice, which are common mouse models of obesity and type 2 diabetes. Muscle injury was produced by cardiotoxin injection, and regeneration was assessed by morphological and immunostaining techniques. Muscle regeneration was delayed in ob/ob and db/db mice, but not in a less severe model of insulin resistance – feeding a high-fat diet to wild-type mice. Angiogenesis, cell proliferation, and myoblast accumulation were also impaired in ob/ob and db/db mice, but not the high-fat diet mice. The impairments in muscle regeneration were associated with impaired macrophage accumulation; macrophages have been shown previously to be required for efficient muscle regeneration. Impaired regeneration in ob/ob and db/db mice could be due partly to the lack of leptin signaling, since leptin is expressed both in damaged muscle and in cultured muscle cells. In summary, impaired muscle regeneration in ob/ob and db/db mice was associated with reduced macrophage accumulation, angiogenesis, and myoblast activity, and could have implications for insulin sensitivity in the skeletal muscle of obese and type 2 diabetic patients.

  12. Diagnosis of arterial sequestration using multidetector CT angiography

    Energy Technology Data Exchange (ETDEWEB)

    Yu Hong, E-mail: yuhong.2002@hotmail.com [Department of Radiology, Changzheng Hospital, Second Military Medical University, Shanghai, 200003 (China); Li Huimin, E-mail: lihuiminphd@163.com [Department of Radiology, Changzheng Hospital, Second Military Medical University, Shanghai, 200003 (China); Liu Shiyuan, E-mail: cjr.liushiyuan@vip.163.com [Department of Radiology, Changzheng Hospital, Second Military Medical University, Shanghai, 200003 (China); Xiao Xiangsheng, E-mail: cjr.xxsh@vip.163.com [Department of Radiology, Changzheng Hospital, Second Military Medical University, Shanghai, 200003 (China)

    2010-11-15

    Background: Arterial sequestration is a rare congenital disorder. The diagnostic evaluation of this condition using multidetector computerized tomography (MDCT) has not been described previously. The purpose of this study was to describe the characteristic features of this disorder and to assess the use of MDCT in visualizing the characteristic anatomic features. Methods: We retrospectively reviewed the records of seven patients with anomalous systemic blood supply to left lower lobe of the lung. All the patients had undergone MDCT angiography. To evaluate the lung parenchyma, bronchial branching pattern, and vascular anatomy, four series of images were systematically reconstructed as follows: contiguous transverse CT scans viewed at mediastinal and pulmonary window settings, oblique coronal and sagittal maximum intensity projections (MIP), multiplanar reconstruction (MPR), and three-dimensional volume-rendered images (VR) of airway and thoracic vascular structures. Results: All 7 cases had isolated and tortuous arterial anatomy from the descending thoracic aorta to the basal segment of the left lower lobe; however, variable distribution of branches was observed. Characteristic findings of anomalous systemic arterial (ASA) supply were distinct from those seen in other pulmonary sequestration syndromes and were well visualized by the use of noninvasive MDCT. Conclusion: Complex CT findings allow clear imaging of arterial sequestration and the ASA blood supply; MDCT angiography has demonstrated its value and accuracy in diagnosing this condition, obviating the use of digital subtraction angiography and magnetic resonance angiography for the diagnosis of arterial sequestration.

  13. Diagnosis of arterial sequestration using multidetector CT angiography

    International Nuclear Information System (INIS)

    Yu Hong; Li Huimin; Liu Shiyuan; Xiao Xiangsheng

    2010-01-01

    Background: Arterial sequestration is a rare congenital disorder. The diagnostic evaluation of this condition using multidetector computerized tomography (MDCT) has not been described previously. The purpose of this study was to describe the characteristic features of this disorder and to assess the use of MDCT in visualizing the characteristic anatomic features. Methods: We retrospectively reviewed the records of seven patients with anomalous systemic blood supply to left lower lobe of the lung. All the patients had undergone MDCT angiography. To evaluate the lung parenchyma, bronchial branching pattern, and vascular anatomy, four series of images were systematically reconstructed as follows: contiguous transverse CT scans viewed at mediastinal and pulmonary window settings, oblique coronal and sagittal maximum intensity projections (MIP), multiplanar reconstruction (MPR), and three-dimensional volume-rendered images (VR) of airway and thoracic vascular structures. Results: All 7 cases had isolated and tortuous arterial anatomy from the descending thoracic aorta to the basal segment of the left lower lobe; however, variable distribution of branches was observed. Characteristic findings of anomalous systemic arterial (ASA) supply were distinct from those seen in other pulmonary sequestration syndromes and were well visualized by the use of noninvasive MDCT. Conclusion: Complex CT findings allow clear imaging of arterial sequestration and the ASA blood supply; MDCT angiography has demonstrated its value and accuracy in diagnosing this condition, obviating the use of digital subtraction angiography and magnetic resonance angiography for the diagnosis of arterial sequestration.

  14. Whole-body magnetic resonance angiography for presurgical planning of free-flap head and neck reconstruction

    International Nuclear Information System (INIS)

    Kramer, Manuel; Nkenke, Emeka; Kikuchi, Keiichi; Schwab, Siegfried A.; Janka, Rolf; Uder, Michael; Lell, Michael

    2012-01-01

    Objectives: Aim of the study was to evaluate if a whole-body magnetic resonance angiography (MRA) protocol meets the requirements to evaluate the donor and host site target vessels for planning of microvascular head and neck reconstructions. Patients and methods: In 20 patients, scheduled for reconstruction of the mandible with fibular free flaps, contrast-enhanced whole-body MRA was performed prior to surgery. 32-Channel 1.5-T MR angiograms were acquired using a 2-step contrast (gadobutrol) injection scheme to visualize the arterial vasculature from head to feet. Maximum intensity projection and multiplanar reconstruction technique was employed to visualize MRA data. For image evaluation the arterial tree was divided into 51 segments. The presence of artefacts impairing diagnostic quality was noted. Evaluable segments were assessed regarding the presence of stenoses >50% diameter reduction, occlusions or aneurysms. Results: No adverse reactions or complications occurred. Of 1020 vessel segments 1003 (98.3%) were evaluable. 36 stenoses >50%, 50 occlusions and one aneurysm were observed. In 21 of 40 lower limbs relevant atherosclerotic changes were depicted. Conclusion: Whole-body MRA proved to be a suitable three-dimensional, noninvasive, nonionising modality for preoperative evaluation of the entire arterial vasculature.

  15. Pediatric CT angiography

    International Nuclear Information System (INIS)

    Siegel, M.J.

    2005-01-01

    Advances in CT technology are having profound impact on imaging children and have made CT angiography possible even in neonates. Even with the tiny anatomy of neonates, small volumes of contrast material, and small venous access catheters, successful CT angiography can be performed with attention to detail. Meticulous attention to patient preparation, the proper selection of technical factors, and optimal delivery of contrast material are crucial. Data post-processing and the creation of 3-D reconstructions are also essential in establishing a correct diagnosis. The applications fo CT angiography are different in children than in adults and most applications in children involve assessment of congenital and postoperative vascular and cardiac diseases. The use of CT angiography offers the opportunity to eliminate the long periods of sedation associated with MR and reduce the radiation exposure associated with conventional angiography. Generally, the benefits of CT angiography in children outweigh the risk, namely that of radiation exposure. However, care must still be taken to minimize the radiation exposure. (orig.)

  16. Renal MR angiography and perfusion in the pig using hyperpolarized water.

    Science.gov (United States)

    Wigh Lipsø, Kasper; Hansen, Esben Søvsø Szocska; Tougaard, Rasmus Stilling; Laustsen, Christoffer; Ardenkjaer-Larsen, Jan Henrik

    2017-09-01

    To study hyperpolarized water as an angiography and perfusion tracer in a large animal model. Protons dissolved in deuterium oxide (D 2 O) were hyperpolarized in a SPINlab dissolution dynamic nuclear polarization (dDNP) polarizer and subsequently investigated in vivo in a pig model at 3 Tesla (T). Approximately 15 mL of hyperpolarized water was injected in the renal artery by hand over 4-5 s. A liquid state polarization of 5.3 ± 0.9% of 3.8 M protons in 15 mL of deuterium oxide was achieved with a T 1 of 24 ± 1 s. This allowed injection through an arterial catheter into the renal artery and subsequently high-contrast imaging of the entire kidney parenchyma over several seconds. The dynamic images allow quantification of tissue perfusion, with a mean cortical perfusion of 504 ± 123 mL/100 mL/min. Hyperpolarized water MR imaging was successfully demonstrated as a renal angiography and perfusion method. Quantitative perfusion maps of the kidney were obtained in agreement with literature and control experiments with gadolinium contrast. Magn Reson Med 78:1131-1135, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

  17. DB Energie 2020. Implementation of sustainability strategy DB2020; DB Energie 2020. Die Umsetzung der Nachhaltigkeitsstrategie DB2020

    Energy Technology Data Exchange (ETDEWEB)

    Witschke, Hans-Juergen [DB Energie GmbH, Frankfurt am Main (Germany)

    2013-06-15

    As a worldwide provider of mobility and logistics services and one of the biggest employers in Germany, Deutsche Bahn (DB) bears a special responsibility for customers, its own staff, the environment and society as a whole. In order to meet this responsibility, it has made the consistent implementation of the DB Energie 2020 sustainability concept an essential element of its business strategy. Following this line of business provides DB with good opportunities on the one hand but also carries risks and challenges on the other. (orig.)

  18. Renal magnetic resonance angiography at 3.0 Tesla using a 32-element phased-array coil system and parallel imaging in 2 directions.

    Science.gov (United States)

    Fenchel, Michael; Nael, Kambiz; Deshpande, Vibhas S; Finn, J Paul; Kramer, Ulrich; Miller, Stephan; Ruehm, Stefan; Laub, Gerhard

    2006-09-01

    The aim of the present study was to assess the feasibility of renal magnetic resonance angiography at 3.0 T using a phased-array coil system with 32-coil elements. Specifically, high parallel imaging factors were used for an increased spatial resolution and anatomic coverage of the whole abdomen. Signal-to-noise values and the g-factor distribution of the 32 element coil were examined in phantom studies for the magnetic resonance angiography (MRA) sequence. Eleven volunteers (6 men, median age of 30.0 years) were examined on a 3.0-T MR scanner (Magnetom Trio, Siemens Medical Solutions, Malvern, PA) using a 32-element phased-array coil (prototype from In vivo Corp.). Contrast-enhanced 3D-MRA (TR 2.95 milliseconds, TE 1.12 milliseconds, flip angle 25-30 degrees , bandwidth 650 Hz/pixel) was acquired with integrated generalized autocalibrating partially parallel acquisition (GRAPPA), in both phase- and slice-encoding direction. Images were assessed by 2 independent observers with regard to image quality, noise and presence of artifacts. Signal-to-noise levels of 22.2 +/- 22.0 and 57.9 +/- 49.0 were measured with (GRAPPAx6) and without parallel-imaging, respectively. The mean g-factor of the 32-element coil for GRAPPA with an acceleration of 3 and 2 in the phase-encoding and slice-encoding direction, respectively, was 1.61. High image quality was found in 9 of 11 volunteers (2.6 +/- 0.8) with good overall interobserver agreement (k = 0.87). Relatively low image quality with higher noise levels were encountered in 2 volunteers. MRA at 3.0 T using a 32-element phased-array coil is feasible in healthy volunteers. High diagnostic image quality and extended anatomic coverage could be achieved with application of high parallel imaging factors.

  19. Design of the 1.5 MW, 30-96 MHz ultra-wideband 3 dB high power hybrid coupler for Ion Cyclotron Resonance Frequency (ICRF) heating in fusion grade reactor

    Energy Technology Data Exchange (ETDEWEB)

    Yadav, Rana Pratap, E-mail: ranayadav97@gmail.com; Kumar, Sunil; Kulkarni, S. V. [Thapar University, Patiala, Punjab 147004, India and Institute for Plasma Research, Gandhinagar 382428 (India)

    2016-01-15

    Design and developmental procedure of strip-line based 1.5 MW, 30-96 MHz, ultra-wideband high power 3 dB hybrid coupler has been presented and its applicability in ion cyclotron resonance heating (ICRH) in tokamak is discussed. For the high power handling capability, spacing between conductors and ground need to very high. Hence other structural parameters like strip-width, strip thickness coupling gap, and junction also become large which can be gone upto optimum limit where various constrains like fabrication tolerance, discontinuities, and excitation of higher TE and TM modes become prominent and significantly deteriorates the desired parameters of the coupled lines system. In designed hybrid coupler, two 8.34 dB coupled lines are connected in tandem to get desired coupling of 3 dB and air is used as dielectric. The spacing between ground and conductors are taken as 0.164 m for 1.5 MW power handling capability. To have the desired spacing, each of 8.34 dB segments are designed with inner dimension of 3.6 × 1.0 × 40 cm where constraints have been significantly realized, compensated, and applied in designing of 1.5 MW hybrid coupler and presented in paper.

  20. MELCOR DB Construction for the Severe Accident Analysis DB

    International Nuclear Information System (INIS)

    Song, Y. M.; Ahn, K. I.

    2011-01-01

    The Korea Atomic Energy Research Institute (KAERI) has been constructing a severe accident analysis database (DB) under a National Nuclear R and D Program. In particular, an MAAP (commercial code being widely used in industries for integrated severe accident analysis) DB for many scenarios including a station blackout (SBO) has been completed. This paper shows the MELCOR DB construction process with examples of SBO scenarios, and the results will be used for a comparison with the MAAP DB

  1. The galenic venous system: Surgical anatomy and its angiographic and magnetic resonance venographic correlations

    International Nuclear Information System (INIS)

    Kilic, Tuerker; Ozduman, Koray; Cavdar, Safiye; Oezek, M. Memet; Pamir, M. Necmettin

    2005-01-01

    Objective: This study aims at evaluating the adequacy of digital subtraction angiography and magnetic resonance venography in imaging of the galenic venous system for surgical planning of approaches to the pineal region. Anatomical dissections were carried out in 10 cadavers of several age groups and these were compared to imaging findings in 10 living subjects. Methods: The presence or absence of 10 predetermined veins or vein groupings belonging to the galenic venous system were prospectively analyzed in 10 cadaver dissections and imaging findings of 10 age matched human subjects. The studied vessels were the vein of galen, the internal cerebral veins, both basal vein of Rosenthals, internal occipital vein, occipitotemporal veins, precentral cerebellar veins, tectal veins, pineal veins, superior vermian veins (including superior cerebellar veins (SCVs)) and posterior pericallosal veins. Each of the subjects had both digital subtraction angiography and magnetic resonance venography studies performed. Diagnostic digital subtraction angiography was performed using the transfemoral route and the venous phase was used for the study. Magnetic resonance venography was performed in 1.5 T MRI equipment using the 2D-TOF sequence. All studies were reported to be normal. Results: There was wide variation in the anatomy of the galenic venous system. There were interpersonal, intrapersonal and age related variations. Both the digital subtraction angiography and the magnetic resonance venography were efficient at demonstrating large veins. However, smaller veins were less readily demonstrated in either study. The general sensitivities of the digital subtraction angiography and the magnetic resonance venography for the galenic venous system were 45.5% and 32.5%, respectively. Surgically important veins were missed in most studies. Conclusions: Anatomically, the galenic venous system is highly variable. This variability is caused by interpersonal, intrapersonal and age related

  2. The galenic venous system: Surgical anatomy and its angiographic and magnetic resonance venographic correlations

    Energy Technology Data Exchange (ETDEWEB)

    Kilic, Tuerker [Marmara University, Department of Neurosurgery, PK 53, Maltepe, 81532 Istanbul (Turkey) and Marmara University, Department of Anatomy, Istanbul (Turkey)]. E-mail: turkilic@tnn.net; Ozduman, Koray [Marmara University, Department of Neurosurgery, PK 53, Maltepe, 81532 Istanbul (Turkey); Cavdar, Safiye [Marmara University, Department of Anatomy, Istanbul (Turkey); Oezek, M. Memet [Marmara University, Department of Neurosurgery, PK 53, Maltepe, 81532 Istanbul (Turkey); Pamir, M. Necmettin [Marmara University, Department of Neurosurgery, PK 53, Maltepe, 81532 Istanbul (Turkey)

    2005-11-01

    Objective: This study aims at evaluating the adequacy of digital subtraction angiography and magnetic resonance venography in imaging of the galenic venous system for surgical planning of approaches to the pineal region. Anatomical dissections were carried out in 10 cadavers of several age groups and these were compared to imaging findings in 10 living subjects. Methods: The presence or absence of 10 predetermined veins or vein groupings belonging to the galenic venous system were prospectively analyzed in 10 cadaver dissections and imaging findings of 10 age matched human subjects. The studied vessels were the vein of galen, the internal cerebral veins, both basal vein of Rosenthals, internal occipital vein, occipitotemporal veins, precentral cerebellar veins, tectal veins, pineal veins, superior vermian veins (including superior cerebellar veins (SCVs)) and posterior pericallosal veins. Each of the subjects had both digital subtraction angiography and magnetic resonance venography studies performed. Diagnostic digital subtraction angiography was performed using the transfemoral route and the venous phase was used for the study. Magnetic resonance venography was performed in 1.5 T MRI equipment using the 2D-TOF sequence. All studies were reported to be normal. Results: There was wide variation in the anatomy of the galenic venous system. There were interpersonal, intrapersonal and age related variations. Both the digital subtraction angiography and the magnetic resonance venography were efficient at demonstrating large veins. However, smaller veins were less readily demonstrated in either study. The general sensitivities of the digital subtraction angiography and the magnetic resonance venography for the galenic venous system were 45.5% and 32.5%, respectively. Surgically important veins were missed in most studies. Conclusions: Anatomically, the galenic venous system is highly variable. This variability is caused by interpersonal, intrapersonal and age related

  3. Catheter versus non-catheter angiography in isolated third nerve palsy

    International Nuclear Information System (INIS)

    Lee, A.G.

    2007-01-01

    To discuss the controversies surrounding the indications for catheter angiography versus non-catheter and less invasive angiography techniques (e.g. magnetic resonance angiography (MRA) and computerized tomography angiography (CTA)) in the evaluation of patients with a third nerve palsy. Clinical opinion-perspective and literature review. The patient with an isolated third nerve palsy might have a vasculopathic (and typically benign, self limited course) etiology or a life threatening intracranial posterior communicating artery aneurysm. Although it is clear that non-isolated third nerve palsies require imaging directed at the topographical localization of the clinical findings, the evaluation of the neurologically isolated third nerve palsy remains controversial. The completeness of the external (i.e. somatic) motor dysfunction and the presence or absence of internal (i.e. pupillary) dysfunction are generally used to guide the choice of initial neuroimaging. Advances in MRA and CTA technology have reduced but not eliminated our dependence upon catheter angiography in this setting. A properly performed and interpreted MRA or CTA probably will be able to detect greater than 95 % of aneurysms producing a third nerve palsy. The issues surrounding the use of catheter angiography in third nerve palsy are reviewed. If the clinician is highly confident in the capability, availability, and reliability of the neuroradiologist and of their institutional experience and quality of less invasive non-catheter MRA and CTA and if the risk of aneurysm is low or if the risk of angiography is high (e.g. elderly, renal failure, iodinated contrast allergy, risk of stroke) then MRI and MRA (or CTA) may be a reasonable alternative to catheter angiography. Patients with a moderate or uncertain risk of aneurysm and a lower risk for catheter angiography or if there is a low confidence in the quality or the interpretation of the institutional MRA (or CTA) may still require catheter

  4. Children's (Pediatric) Magnetic Resonance Imaging

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    Full Text Available ... MRI) exam. View full size with caption Pediatric Content Some imaging tests and treatments have special pediatric considerations. The teddy bear denotes child-specific content. Related Articles and Media Catheter Angiography Magnetic Resonance, ...

  5. Catheter Angiography

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    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician Resources Professions Site Index A-Z Catheter Angiography Catheter angiography ...

  6. Catheter Angiography

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    Full Text Available ... you are pregnant and discuss any recent illnesses, medical conditions, medications you're taking and allergies, especially ... is Catheter Angiography? Angiography is a minimally invasive medical test that helps physicians diagnose and treat medical ...

  7. Catheter Angiography

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    Full Text Available ... far outweighs the risk. If you have a history of allergy to x-ray contrast material, your ... Angiography (CTA) X-ray, Interventional Radiology and Nuclear Medicine Radiation Safety Images related to Catheter Angiography Sponsored ...

  8. Catheter Angiography

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    Full Text Available ... Angiography is a minimally invasive medical test that helps physicians diagnose and treat medical conditions. Angiography uses ... has narrowed the arteries to the legs and help prepare for endovascular intervention or surgery. detect disease ...

  9. Extremely long posterior communicating artery diagnosed by MR angiography: report of two cases.

    Science.gov (United States)

    Uchino, Akira; Suzuki, Chihiro; Tanaka, Masahiko

    2015-07-01

    We report two cases of an extremely long left posterior communicating artery (PCoA) diagnosed by magnetic resonance (MR) angiography. The PCoA arose from the normal point of the supraclinoid internal carotid artery and fused with the posterior cerebral artery (PCA) at its posterior ambient segment, forming an extremely long PCoA and extremely long precommunicating segment of the PCA. To our knowledge, this is the first report of such variation. Careful observation of MR angiographic images is important for detecting rare arterial variations. To identify these anomalous arteries on MR angiography, partial maximum-intensity-projection images are useful.

  10. Catheter Angiography

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    Full Text Available ... lies. The catheter used in angiography is a long plastic tube about as thick as a strand of spaghetti. top of page How does the procedure work? Catheter angiography works much the same as a ...

  11. Catheter Angiography

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    Full Text Available ... story about radiology? Share your patient story here Images × Image Gallery Interventional radiologist performing an angiography exam View ... ray, Interventional Radiology and Nuclear Medicine Radiation Safety Images related to Catheter Angiography Sponsored by Please note ...

  12. Abdominal MR angiography

    International Nuclear Information System (INIS)

    Wegmueller, H.; Vock, P.

    1993-01-01

    The two techniques currently most often used for MR angiography, those based on time-of-flight effects and on phase-contrast, are introduced, and our results with three-dimensional phase contrast angiography of the abdomen are presented. Several basic differences from other imaging procedures render MR angiography clinically useful for screening for renal artery stenosis in critical situations, such as renal failure or intolerance to contrast agents. In the future, the spectrum of applications of MR angiography will broaden and include other indications, such as portal venous hypertension and follow-up studies after surgical portal systemic shunting. (orig.) [de

  13. Children's (Pediatric) Magnetic Resonance Imaging

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    Full Text Available ... or thyroid problems. Any of these conditions may influence the decision on whether contrast material will be ... bear denotes child-specific content. Related Articles and Media Catheter Angiography Magnetic Resonance, Functional (fMRI) - Brain Children's ( ...

  14. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... bear denotes child-specific content. Related Articles and Media MR Angiography (MRA) Magnetic Resonance, Functional (fMRI) - Brain ... the web pages found at these links. About Us | Contact Us | FAQ | Privacy | Terms of Use | Links | ...

  15. Children's (Pediatric) Magnetic Resonance Imaging

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    Full Text Available ... bear denotes child-specific content. Related Articles and Media Catheter Angiography Magnetic Resonance, Functional (fMRI) - Brain Children's ( ... the web pages found at these links. About Us | Contact Us | FAQ | Privacy | Terms of Use | Links | ...

  16. Children's (Pediatric) Magnetic Resonance Imaging

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    Full Text Available ... Related Articles and Media Catheter Angiography Magnetic Resonance, Functional (fMRI) - Brain Children's (Pediatric) CT (Computed Tomography) Magnetic ... the possible charges you will incur. Web page review process: This Web page is reviewed regularly by ...

  17. Clinical findings of intracranial vertebral artery disease using magnetic resonance angiography.

    Science.gov (United States)

    Liu, Lu-Han; Chen, Clayton Chi-Chang; Chang, Ming-Hong

    2004-09-01

    The vertebral artery lesion has a variety of clinical characteristics. We sought to clarify the clinical patterns and the location of the intracranial vertebral artery (ICVA) diseases according to analyses of images obtained using magnetic resonance angiography (MRA). We studied vascular lesions, risk factors, symptoms, signs, and outcomes in 35 patients with ICVA disease (3 had bilateral occlusion; 9, unilateral occlusion; 6, bilateral stenosis; and 17, unilateral stenosis). The most common site of unilateral and bilateral lesions was the distal ICVA after the origin of posterior inferior cerebellar artery (PICA). We found accompanying basilar artery disease in 28.6% of patients with unilateral and bilateral ICVA disease. The majority of the ICVA lesions were associated with internal carotid arteries disease (48.8%). The common vascular risk factors were hypertension (71%), diabetes mellitus (34%), hyperlipidemia (31%), smoking (29%), and coronary artery disease (23%). Eighteen patients (51.4%) had transient ischemic attacks (TIAs) only, 10 patients (28.6%) had TIAs before stroke, and 5 patients (14.3%) had strokes without TIAs. Most patients (80%) with TIAs, with or without stroke, had multiple episodes. Vertigo or dizziness, ataxia, limbs weakness and abnormal gait were the common symptoms and signs. At 6 months follow-up, 66.7% patients had no symptoms or only slight symptoms that caused no disability. Our data showed (1) the usual location of ICVA disease (occlusion or severe stenosis) was distal to PICA, especially near the vertebrobasilar junction; (2) the risk factors were hypertension, diabetes mellitus, hyperlipidemia, smoking, and coronary artery disease; (3) patients with ICVA disease had a high frequency of accompanying internal carotid, middle cerebral, or basilar artery disease; (4) vertigo or dizziness, and ataxia were the common symptoms and signs; (5) TIA was the most common clinical pattern; (6) the outcome was favorable, except in cases with

  18. Magnetic Resonance Angiography of the pulmonary veins: TOF 3D versus 2D

    International Nuclear Information System (INIS)

    Carriero, Alessandro; Magarelli, Nicola; Gatta, Stefania; Pinto, Dario; Bonomo, Lorenzo; Baratto, Michele; Scapati, Carmelo

    1997-01-01

    The aim of this work was to optimize the magnetic resonance angiography (MRA) technique for the selective study of the pulmonary veins. Twenty patients (13 men and 7 women; mean age: 30.5 years) were examined. MRA was performed with a 1 T superconductive magnet and the 3D time of flight (TOF) technique. Fast sequences (3D FISP : TR 58 ms, TE 6 ms, FA 20 deg, matrix 192 x 256; and 2D FLASH: TR 44 ms, TE 10 ms, FA 30 deg, matrix 192 x 256) were used. Coronal and sagittal images were submitted to MIP processing; presaturation pulses for the pulmonary arteries were located in the mediastinal region. In the right lung 3D TOF on the coronal plane well showed 124 veins, while sagittal images showed 106 veins. In the left lung, 3D TOF on the coronal plane well showed 96 vessels, while sagittal images showed 44 vessels. In the right lung, 2D TOF on the coronal plane well showed 54 veins, while sagittal images showed 36 vessels. In the left lung, 2D TOF on the coronal plane well showed 22 vessels, while sagittal images showed 21 vessels. Therefore 3D TOF yielded better than 2D TOF (p<0.05). To conclude, 3D TOF with contrast agent administration is a useful tool to study the pulmonary veins; those with a larger caliber are better depicted and the integration of coronal and sagittal images depicts more veins

  19. Catheter Angiography

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    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician ... Catheter Angiography? Angiography is a minimally invasive medical test that helps physicians diagnose and treat medical conditions. ...

  20. Children's (Pediatric) Magnetic Resonance Imaging

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    Full Text Available ... immediately after the exam. A few patients experience side effects from the contrast material, including nausea and local ... Related Articles and Media Catheter Angiography Magnetic Resonance, Functional (fMRI) - Brain Children's (Pediatric) CT (Computed Tomography) Magnetic ...

  1. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... structures of the brain and can also provide functional information (fMRI) in selected cases. MR images of ... Articles and Media MR Angiography (MRA) Magnetic Resonance, Functional (fMRI) - Brain Head and Neck Cancer Treatment Brain ...

  2. Renal Artery Stenosis Evaluated with 3D-Gd-Magnetic Resonance Angiography Using Transstenotic Pressure Gradient as the Standard of Reference. A Multireader Study

    International Nuclear Information System (INIS)

    Ekloef, H.; Ahlstrom, H.; Bostrom, A.; Bergqvist, D.; Andren, B.; Karacagil, S.; Nyman, R.

    2005-01-01

    Purpose: To evaluate 3D-Gd-magnetic resonance angiography (MRA) in detecting hemodynamically significant renal artery stenosis (RAS). Material and Methods: Thirty patients evaluated for atherosclerotic RAS by MRA and digital subtraction angiography (DSA) were retrospectively included. Standard of reference for hemodynamically significant RAS was a transstenotic gradient of 15 mmHg. DSA visualized 60 main renal arteries and 9 accessory arteries. Pressure gradient measurement (PGM) was available from 61 arteries. Three radiologists evaluated all examinations independently in a blinded fashion. Results: RAS was present in 26 arteries. On MRA, each reader identified 4 of 9 accessory renal arteries, a detection rate of 44%. The three readers correctly classified 22/25/22 of the 26 vessels with a significant gradient as >60% RAS and 31/25/32 of the 35 with a significant gradient as <60% RAS on MRA. Interobserver agreement was substantial. MRA image quality was adequate for RAS evaluations in all patients. ROC curves indicated that MRA is an adequate method for evaluating RAS. When screening for RAS, a 50% diameter reduction cut-off is better than 60%. RAS with 40-80% diameter reductions accounted for 65% of discrepancies. Conclusion: MRA is an adequate method for evaluating RAS limited mainly by poor detection rate for accessory renal arteries

  3. Vertebral artery variations at the C1-2 level diagnosed by magnetic resonance angiography

    Energy Technology Data Exchange (ETDEWEB)

    Uchino, Akira; Saito, Naoko; Watadani, Takeyuki; Okada, Yoshitaka; Kozawa, Eito; Nishi, Naoko; Mizukoshi, Waka; Inoue, Kaiji; Nakajima, Reiko; Takahashi, Masahiro [Saitama Medical University International Medical Center, Department of Diagnostic Radiology, Hidaka, Saitama (Japan)

    2012-01-15

    The craniovertebral junction is clinically important. The vertebral artery (VA) in its several variations runs within this area. We report the prevalence of these VA variations on magnetic resonance angiography (MRA). We retrospectively reviewed MRA images, obtained using two 1.5-T imagers, of 2,739 patients, and paid special attention to the course and branching of the VA at the level of the C1-2 vertebral bodies. There were three types of VA variation at the C1-2 level: (1) persistent first intersegmental artery (FIA), (2) VA fenestration, and (3) posterior inferior cerebellar artery (PICA) originating from the C1/2 level. The overall prevalence of these three variations was 5.0%. There was no laterality in frequency, but we found female predominance (P < 0.05). We most frequently observed the persistent FIA (3.2%), which was sometimes bilateral. We found VA fenestration (0.9%) and PICA of C1/2 origin (1.1%) with almost equal frequency. Two PICAs of C1/2 origin had no normal VA branch. We frequently observed VA variations at the C1-2 level and with female predominance. The persistent FIA was most prevalent and sometimes seen bilaterally. Preoperative identification of these variations in VA is necessary to avoid complications during surgery at the craniovertebral junction. (orig.)

  4. Proteases in Plasma and Kidney of db/db Mice as Markers of Diabetes-Induced Nephropathy

    Science.gov (United States)

    Hadler-Olsen, E.; Winberg, J.-O.; Reinholt, F. P.; Larsen, T.; Uhlin-Hansen, L.; Jenssen, T.; Berg, E.; Kolset, S. O.

    2011-01-01

    Db/db mice are overweight, dyslipidemic and develop diabetic complications, relevant for similar complications in human type 2 diabetes. We have used db/db and db/+ control mice to investigate alterations in proteinase expression and activity in circulation and kidneys by SDS-PAGE zymography, electron microscopy, immunohistochemistry, Western blotting, and in situ zymography. Plasma from db/db mice contained larger amounts of serine proteinases compared to db/+ mice. Kidneys from the db/db mice had a significantly larger glomerular surface area and somewhat thicker glomerular basement membranes compared to the db/+ mice. Furthermore, kidney extracts from db/+ mice contained metalloproteinases with M r of approximately 92000, compatible with MMP-9, not observed in db/db mice. These results indicate that higher levels of serine proteinases in plasma may serve as potential markers for kidney changes in db/db mice, whereas a decrease in MMP-9 in the kidney may be related to the glomerular changes. PMID:22363890

  5. Catheter Angiography

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    Full Text Available ... further information please consult the ACR Manual on Contrast Media and its references. The risk of serious allergic ... View full size with caption Related Articles and Media Angioplasty and Vascular Stenting MR Angiography (MRA) Contrast Materials CT Angiography (CTA) X-ray, Interventional Radiology ...

  6. Venous reflux on contrast-enhanced head and neck magnetic resonance angiography: Analysis of causative factors

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Dong Jae; Lee, Eun Ja [Dept. of Radiology, Dongguk University Ilsan Hospital, Goyang (Korea, Republic of); Bae, Jong Myon [Dept. of Preventive Medicine, Jeju National University School of Medicine, Jeju (Korea, Republic of)

    2016-12-15

    The purpose of this study was to analyze the causative factors of venous reflux on contrast-enhanced head and neck magnetic resonance angiography. We retrospectively reviewed 150 patients with right-arm injections and 150 patients with left-arm injections. We included the age, gender, body mass index, history of hypertension, and history of diabetes mellitus in the evaluation of all patients. We measured the shortest width of the left or right brachiocephalic vein (BCV), the diameter of the aortic arch, and the distance between the sternum and vertebral body. The relationship between these factors and the venous reflux was analyzed. In patients with venous reflux, we performed qualitative image scoring for suboptimal images. In patients with venous reflux, the image quality of the left-arm injection group was significantly inferior to the image quality of the right-arm injection group. The mean age and the male-to-female ratio of patients with venous reflux were significantly higher than those of patients without venous reflux. In patients receiving the left-arm injection, the mean shortest width of the left BCV was significantly narrower in patients with venous reflux than in patients without venous reflux. A left-arm injection should be avoided, especially in elderly patients, to acquire an optimal image.

  7. Venous reflux on contrast-enhanced head and neck magnetic resonance angiography: Analysis of causative factors

    International Nuclear Information System (INIS)

    Shin, Dong Jae; Lee, Eun Ja; Bae, Jong Myon

    2016-01-01

    The purpose of this study was to analyze the causative factors of venous reflux on contrast-enhanced head and neck magnetic resonance angiography. We retrospectively reviewed 150 patients with right-arm injections and 150 patients with left-arm injections. We included the age, gender, body mass index, history of hypertension, and history of diabetes mellitus in the evaluation of all patients. We measured the shortest width of the left or right brachiocephalic vein (BCV), the diameter of the aortic arch, and the distance between the sternum and vertebral body. The relationship between these factors and the venous reflux was analyzed. In patients with venous reflux, we performed qualitative image scoring for suboptimal images. In patients with venous reflux, the image quality of the left-arm injection group was significantly inferior to the image quality of the right-arm injection group. The mean age and the male-to-female ratio of patients with venous reflux were significantly higher than those of patients without venous reflux. In patients receiving the left-arm injection, the mean shortest width of the left BCV was significantly narrower in patients with venous reflux than in patients without venous reflux. A left-arm injection should be avoided, especially in elderly patients, to acquire an optimal image

  8. Comparison of 3D magnetic resonance imaging and digital subtraction angiography for intracranial artery stenosis

    Energy Technology Data Exchange (ETDEWEB)

    Park, Ji Eun; Jung, Seung Chai; Kim, Ho Sung; Choi, Choong-Gon; Kim, Sang Joon; Lee, Deok Hee [University of Ulsan College of Medicine, Department of Radiology and Research Institute of Radiology, Asan Medical Center, Seoul (Korea, Republic of); Lee, Sang Hun; Kwon, Sun U.; Kang, Dong-Wha; Kim, Jong S. [University of Ulsan College of Medicine, Department of Neurology, Ulsan (Korea, Republic of); Jeon, Ji Young [Gachon University, Department of Radiology, Gil Medical Center, Incheon (Korea, Republic of); Lee, Ji Ye [Soonchunhyang University Bucheon Hospital, Department of Radiology, Bucheon (Korea, Republic of); Kim, Seon-Ok [University of Ulsan College of Medicine, Department of Clinical Epidemiology and Biostatistics, Asan Medical Center, Seoul (Korea, Republic of)

    2017-11-15

    To compare three-dimensional high-resolution magnetic resonance imaging (3D HR-MRI) and digital subtraction angiography (DSA) for diagnosing and evaluating stenosis in the entire circle of Willis. The study included 516 intracranial arteries from 43 patients with intracranial artery stenosis (ICAS) who underwent both 3D HR-MRI and DSA within 1 month. Two readers independently diagnosed atherosclerosis, dissection, moyamoya disease and vasculitis, rated their diagnostic confidence for each vessel and measured the luminal diameters. Reference standard was made from clinico-radiologic diagnosis. Diagnostic accuracy, diagnostic confidence, the degree of stenosis and luminal diameter were assessed and compared between both modalities. For atherosclerosis, 3D HR-MRI showed better diagnostic accuracy (P =.03-.003), sensitivity (P =.006-.01) and positive predictive value (P ≤.001-.006) compared to DSA. Overall, the readers were more confident of their diagnosis of ICAS when using 3D HR-MRI (reader 1, P ≤.001-.007; reader 2, P ≤.001-.015). 3D HR-MRI showed similar degree of stenosis (P >.05) and higher luminal diameter (P <.05) compared to DSA. 3D HR-MRI might be useful to evaluate atherosclerosis, with better diagnostic confidence and comparable stenosis measurement compared to DSA in the entire circle of Willis. (orig.)

  9. Evaluation of three-dimensional contrast-enhanced MR angiography in pediatric body vascular lesions

    International Nuclear Information System (INIS)

    Tanaka, Yasunori; Katayama, Hiroshi; Yamamoto, Kazuhiro; Shimizu, Tadafumi; Narabayashi, Isamu

    1998-01-01

    Evaluation of three-dimensional contrast-enhanced MR angiography in the pediatric body vascular lesions. This study examined the usefulness of three-dimensional gadolinium-enhanced magnetic resonance angiography (3D-enhanced MRA) for pediatric body vascular lesions. Fifteen 3D-enhanced MRAs were performed on fourteen pediatric patients aged from one month to fifteen years, using a 3D fast SPGR sequence. Maximum intensity projection (MIP) and multiplanar reconstruction (MPR) images were obtained from the imaging data in all cases, and eleven MIP images were obtained after subtraction of precontrast-enhanced imaging data from postcontrast-enhanced imaging data. In six cases, MIP and MPR images were correlated with cine or digital subtraction angiographies, and the eleven subtracted MIP images were compared with those before subtraction. Clinical usefulness was demonstrated in fourteen (93%) of the fifteen cases, and in seven (64%) of the eleven cases in which subtraction was performed, image quality was improved. In comparison with cine or digital subtraction angiographies, however, only one (17%) MRA was superior. It was considered that 3D-enhanced MRA was useful for pediatric body vascular lesions because of advantages such as lower invasiveness compared with that of conventional angiography, absence of radiation exposure, safety of contrast media, easy availability of MPR images, and short scanning time. In conclusion, if a pediatric body vascular lesion is suspected, 3D-enhanced MRA should be performed before conventional angiography. It also seems that 3D-enhanced MRA may be useful for follow-up. (author)

  10. Children's (Pediatric) Magnetic Resonance Imaging

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    Full Text Available ... of which shows a thin slice of the body. The images can then be studied from different angles by ... about radiology? Share your patient story here Images ... Articles and Media Catheter Angiography Magnetic Resonance, Functional (fMRI) - Brain Children's ( ...

  11. Angiography and interventional radiology of the kidneys

    International Nuclear Information System (INIS)

    Hansmann, J.; Richter, G.M.; Hallscheidt, P.; Duex, M.; Noeldge, G.; Kaufmann, G.W.

    1999-01-01

    For imaging of renal pathology a broad spectrum of radiologic diagnostic procedures are available which are, sometimes and particularly more recently, competing among each other in their diagnostic yield and relevance. For tumorous lesions ultrasound, computed tomography and magnetic resonance imaging are performed predominantly. Angiography is no longer required with the exception of highly selected cases and in some specific preoperative workup requirements. Until recently, catheter based digital subtraction angiography has been considered as gold standard. However, non-invasive techniques such as CT-angiography and MR-angiography are evolving parallel to their quantum leap of resolutions and readiness to use. Nevertheless, well accepted criteria for quality assessement of these new modalities are still lacking. More comparison studies are urgently warranted. Despite the availability of ultrashort pulse sequences applying the T1 relaxation reduction effect of gadolinium enhanced MR techniques overestimation of renal artery stenosis still poses a substantial problem. Renal intervention implies a variety of procedures such as plain angioplasty, stent placement, embolization of traumatic and both benign and malignant tumors. These methods have emerged over the last two decades from a more experimental nature to a fully accepted treatment option. When renal artery angioplasty is embedded in an aggressive approach including stenting as an adjunct for more complex cases, renal ostial lesions and a well organized follow-up regimen its therapeutic potential for treatment of renal insufficiency, malignant hypertension, for organ preservation bears a very high potential. Provided adequate periinterventional drug regimen restenosis rates may be as low as 10%. In highly selected cases capillary embolization might be used as an alternative to nephrectomy with a similar clinical outcome. Particularly the development of superselective small caliber embolization catheters

  12. Detection of aneurysms in subarachnoidal hemorrhage - CT-angiography versus digital subtraction angiography

    International Nuclear Information System (INIS)

    Roehnert, W.; Haenig, V.; Hietschold, V.; Abolmaali, N.

    1998-01-01

    Purpose: The value of CT-angiography (CT-A) for the visualization of intracranial aneurysms was more closely defined by comparison with digital subtraction angiography (DSA). Methods: Over a period of 18 months a total of 106 patients in whom a subarachnoidal hemorrhage had been detected on native CT were examined in parallel by spiral CT and DSA. CT-angiography was performed under standardized parameters and included processing with 3D surface reconstructions. Results: In 64 patients (60.4%) at total of 72 aneurysms were detected. In four cases (6.2%) there were two and in two cases (3.1%) even three aneurysms. The findings of DSA and CTA agreed in 98 cases (92.5%). In four patients (3.8%) a false negative results was obtained in CTA and the initial DSA. Conclusions: Digital subtraction angiography must still be considered as the gold standard in the diagnosis of cerebral aneurysms. On account of its excellent spatial delineation of aneurysms and possibilities for exact measurements, CT-angiography represents a valuable, supplementary method - in some cases also an alternative method - to digital subtraction angiography. (orig.) [de

  13. Mastering MariaDB

    CERN Document Server

    Razzoli, Federico

    2014-01-01

    This book is intended for intermediate users who want to learn how to administrate a MariaDB server or a set of servers. It is aimed at MariaDB users, and hence working knowledge of MariaDB is a prerequisite.

  14. Portulaca oleracea Ameliorates Diabetic Vascular Inflammation and Endothelial Dysfunction in db/db Mice

    Science.gov (United States)

    Lee, An Sook; Lee, Yun Jung; Lee, So Min; Yoon, Jung Joo; Kim, Jin Sook; Kang, Dae Gill; Lee, Ho Sub

    2012-01-01

    Type 2 diabetes is associated with significantly accelerated rates of micro- and macrovascular complications such as diabetic vascular inflammation and endothelial dysfunction. In the present study, we investigated the protective effect of the aqueous extract of Portulaca oleracea L. (AP), an edible plant used as a folk medicine, on diabetic vascular complications. The db/db mice were treated with AP (300 mg/kg/day, p.o.) for 10 weeks, and AP treatment markedly lowered blood glucose, plasma triglyceride, plasma level of LDL-cholesterol, and systolic blood pressure in diabetic db/db mice. Furthermore, AP significantly increased plasma level of HDL-cholesterol and insulin level. The impairment of ACh- and SNP-induced vascular relaxation of aortic rings were ameliorated by AP treatment in diabetic db/db mice. This study also showed that overexpression of VCAM-1, ICAM-1, E-selectin, MMP-2, and ET-1 were observed in aortic tissues of untreated db/db mice, which were significantly suppressed by treatment with AP. We also found that the insulin immunoreactivity of the pancreatic islets remarkably increased in AP treated db/db mice compared with untreated db/db mice. Taken together, AP suppresses hyperglycemia and diabetic vascular inflammation, and prevents the development of diabetic endothelial dysfunction for the development of diabetes and its vascular complications. PMID:22474522

  15. Coronary MR angiography: current status

    International Nuclear Information System (INIS)

    Danias, P.G.; Manning, W.J.

    2000-01-01

    Since first described in the early 1990s, coronary magnetic resonance angiography (MRA) has evolved as a promising noninvasive modality for imaging of the coronary arteries and evaluation of coronary artery disease. Despite technical limitations, coronary MRA has established value for imaging of anomalous coronary arteries and assessment of bypass graft patency. Current research focuses on the development of optimal respiratory compensation strategies, improved spatial and temporal resolution and faster acquisition of image data. The accurate detection of stenoses and assessment of the severity of coronary atherosclerosis is presently being evaluated with large multi-center studies. With further technique enhancements and more clinical experience, coronary MRA is likely to become the dominant noninvasive modality in clinical cardiology. (orig.) [de

  16. Feasibility of magnetic resonance angiography (MRA) follow-up as the primary imaging modality after coiling of intracranial aneurysms

    International Nuclear Information System (INIS)

    Bakker, Nicolaas A.; Metzemaekers, Jan D. M.; Dijk, J. Marc C. van; Mooij, Jan Jakob A.; Groen, Rob J. M.; Westerlaan, Henriette E.; Eshghi, Omid S.

    2010-01-01

    Background: Digital subtraction angiography (DSA) is still regarded as the gold standard for detecting residual flow in treated aneurysms. Recent reports have also shown excellent results from magnetic resonance angiography (MRA) imaging. This is an important observation, since DSA is associated with a risk of medical complications, is time consuming, and is more expensive. Purpose: To determine whether MRA could replace conventional DSA and serve as the primary postinterventional imaging modality in patients with coiled intracranial aneurysms. Material and Methods: We studied a prospectively enrolled cohort of 190 patients treated endovascularly for a first-ruptured and/or unruptured intracranial aneurysm between January 2004 and December 2008. The imaging protocol included a 1.5T time-of-flight (TOF) MRA and a DSA at 3 months (on the same day) and, depending on comparability, a 1.5T TOF-MRA or DSA 1 year after treatment. All images were evaluated by a multidisciplinary panel. Results: In 141/190 patients, both an MRA and DSA were performed after 3-month follow-up. In 2/141 patients (1.4%), (small) neck remnants gave false-negative MRA results. In one patient (0.7%), this led to additional neurosurgical clipping of the aneurysm. In 25/141 patients, future follow-up (>3 months) consisted of DSA because of various reasons. In 24/25 of these patients, primary MRA images alone would invariably have led to additional DSA imaging. Conclusion: The present study shows that 1.5T TOF-MRA is a feasible primary follow-up modality after coiling of intracranial aneurysms. Given our data, we now suggest that, in every patient with a coiled intracranial aneurysm, the first follow-up, 3 months after coiling, should be an MRA study. Only when this MRA is inconclusive (e.g., because of coil artifacts), or in the case of suspicion of recanalization, should DSA be performed additionally

  17. Benefit of cone-beam computed tomography angiography in acute management of angiographically undetectable ruptured arteriovenous malformations.

    Science.gov (United States)

    Rahal, Jason P; Malek, Adel M

    2013-10-01

    Ruptured arteriovenous malformations (AVMs) are a frequent cause of intracerebral hemorrhage (ICH). In some cases, compression from the associated hematoma in the acute setting can partially or completely occlude an AVM, making it invisible on conventional angiography techniques. The authors report on the successful use of cone-beam CT angiography (CBCT-A) to precisely identify the underlying angioarchitecture of ruptured AVMs that are not visible on conventional angiography. Three patients presented with ICH for which they underwent examination with CBCT-A in addition to digital subtraction angiography and other imaging modalities, including MR angiography and CT angiography. All patients underwent surgical evacuation due to mass effect from the hematoma. Clinical history, imaging studies, and surgical records were reviewed. Hematoma volumes were calculated. In all 3 cases, CBCT-A demonstrated detailed anatomy of an AVM where no lesion or just a suggestion of a draining vein had been seen with other imaging modalities. Magnetic resonance imaging demonstrated enhancement in 1 patient; CT angiography demonstrated a draining vein in 1 patient; 2D digital subtraction angiography and 3D rotational angiography demonstrated a suggestion of a draining vein in 2 cases and no finding in the third. In the 2 patients in whom CBCT-A was performed prior to surgery, the demonstrated AVM was successfully resected without evidence of a residual lesion. In the third patient, CBCT-A allowed precise targeting of the AVM nidus using Gamma Knife radiosurgery. Cone-beam CT angiography should be considered in the evaluation and subsequent treatment of ICH due to ruptured AVMs. In cases in which the associated hematoma compresses the AVM nidus, CBCT-A can have higher sensitivity and anatomical accuracy than traditional angiographic modalities, including digital subtraction angiography.

  18. Pulse sequences for contrast-enhanced magnetic resonance imaging

    International Nuclear Information System (INIS)

    Graves, Martin J.

    2007-01-01

    The theory and application of magnetic resonance imaging (MRI) pulse sequences following the administration of an exogenous contrast agent are discussed. Pulse sequences are categorised according to the contrast agent mechanism: changes in proton density, relaxivity, magnetic susceptibility and resonant frequency shift. Applications in morphological imaging, magnetic resonance angiography, dynamic imaging and cell labelling are described. The importance of optimising the pulse sequence for each application is emphasised

  19. Carotid stenosis: a comparison between MR and spiral CT angiography

    Energy Technology Data Exchange (ETDEWEB)

    Magarelli, N.; Carriero, A.; Bonomo, L. [Institute of Radiology, University ``G. D`Annunzio``, Chieti (Italy); Scarabino, T.; Simeone, A.L.; Florio, F. [IRCCS, Foggia (Italy); Salvolini, U. [Department of Neuroradiology, University of Ancona (Italy)

    1998-06-01

    We performed a preliminary study comparing three-dimensional time-of-flight (3 D TOF) magnetic resonance angiography (MRA) and spiral CT angiography (SCTA) in the detection and assessment of internal carotid artery stenosis. Digital subtraction angiography (DSA) was the reference examination. We examined 20 patients with signs of cerebrovascular insufficiency, who underwent MRA, SCTA and DSA within a 3 day period. Both internal carotid arteries were assessed by three blinded readers for degree of stenosis at two different levels (bulb and remaining section) giving a total of 80 assessments. Interobserver variability, sensitivity, specificity, diagnostic accuracy, concordance, overestimation and underestimation were assessed. Interobserver variability was not statistically significant. MRA showed higher sensitivity, specificity, diagnostic accuracy and concordance than SCTA (92.0 % vs 80.8 %, 98.2 % vs 96.4 %, 96.3 % vs 91.3 % and 96.0 % vs 88.0 %, respectively). MRA gave rise to a 5.0 % overestimation rate, whereas SCTA occasioned a 7.5 % underestimation rate. These differences are not statistically significant. These results suggest that MRA is a more useful, noninvasive modality for assessment of the internal carotid artery with a more than 70 % stenosis. (orig.) With 6 figs., 4 tabs., 17 refs.

  20. Carotid stenosis: a comparison between MR and spiral CT angiography

    International Nuclear Information System (INIS)

    Magarelli, N.; Carriero, A.; Bonomo, L.; Scarabino, T.; Simeone, A.L.; Florio, F.; Salvolini, U.

    1998-01-01

    We performed a preliminary study comparing three-dimensional time-of-flight (3 D TOF) magnetic resonance angiography (MRA) and spiral CT angiography (SCTA) in the detection and assessment of internal carotid artery stenosis. Digital subtraction angiography (DSA) was the reference examination. We examined 20 patients with signs of cerebrovascular insufficiency, who underwent MRA, SCTA and DSA within a 3 day period. Both internal carotid arteries were assessed by three blinded readers for degree of stenosis at two different levels (bulb and remaining section) giving a total of 80 assessments. Interobserver variability, sensitivity, specificity, diagnostic accuracy, concordance, overestimation and underestimation were assessed. Interobserver variability was not statistically significant. MRA showed higher sensitivity, specificity, diagnostic accuracy and concordance than SCTA (92.0 % vs 80.8 %, 98.2 % vs 96.4 %, 96.3 % vs 91.3 % and 96.0 % vs 88.0 %, respectively). MRA gave rise to a 5.0 % overestimation rate, whereas SCTA occasioned a 7.5 % underestimation rate. These differences are not statistically significant. These results suggest that MRA is a more useful, noninvasive modality for assessment of the internal carotid artery with a more than 70 % stenosis. (orig.)

  1. Intracranial MR angiography

    International Nuclear Information System (INIS)

    Davis, W.L.; Blatter, D.D.; Parker, D.L.; Robison, R.O.; Harnsberger, H.R.

    1991-01-01

    This paper compares the more traditional three-dimensional (3D) time-of-flight MR angiography with a novel new technique, MOTSA, in the evaluation of both normal and abnormal intracranial anatomy. The authors performed sequential, location-matched 3D TOF and MOTSA MR angiography in 10 subjects with normal and 25 with abnormal intracranial anatomy. Images were evaluated for visualization of specific vessels and depiction of pathologic anatomy. All images were subjected to an objective scoring system. Digital angiography was available in 15 of 25 abnormal cases. In the normal cases, large- and small-vessel visualization was improved. Significant improvement in visualization of venous anatomy was also observed. In the abnormal cases, pathologic anatomy was better visualized, providing important diagnostic information. Multiple overlapping thin-slab-acquisition MR angiography demonstrates vessel visualization that is increased over that of 3D TOF MR angiography in both normal and abnormal cases. Because of the decrease in saturation effects and phase dispersion, MOTSA is especially useful in the evaluation of complex intracranial vascular abnormalities

  2. Low insertion loss SOI microring resonator integrated with nano-taper couplers

    DEFF Research Database (Denmark)

    Pu, Minhao; Frandsen, Lars Hagedorn; Ou, Haiyan

    2009-01-01

    We demonstrate a microring resonator working at TM mode integrated with nano-taper couplers with 3.6dB total insertion loss. The measured insertion loss of the nano-taper coupler was only 1.3dB for TM mode....

  3. Zinc Prevents the Development of Diabetic Cardiomyopathy in db/db Mice

    Directory of Open Access Journals (Sweden)

    Shudong Wang

    2017-03-01

    Full Text Available Diabetic cardiomyopathy (DCM is highly prevalent in type 2 diabetes (T2DM patients. Zinc is an important essential trace metal, whose deficiency is associated with various chronic ailments, including vascular diseases. We assessed T2DM B6.BKS(D-Leprdb/J (db/db mice fed for six months on a normal diet containing three zinc levels (deficient, adequate, and supplemented, to explore the role of zinc in DCM development and progression. Cardiac function, reflected by ejection fraction, was significantly decreased, along with increased left ventricle mass and heart weight to tibial length ratio, in db/db mice. As a molecular cardiac hypertrophy marker, atrial natriuretic peptide levels were also significantly increased. Cardiac dysfunction and hypertrophy were accompanied by significantly increased fibrotic (elevated collagen accumulation as well as transforming growth factor β and connective tissue growth factor levels and inflammatory (enhanced expression of tumor necrosis factor alpha, interleukin-1β, caspase recruitment domain family member 9, and B-cell lymphoma/leukemia 10, and activated p38 mitogen-activated protein kinase responses in the heart. All these diabetic effects were exacerbated by zinc deficiency, and not affected by zinc supplementation, respectively. Mechanistically, oxidative stress and damage, mirrored by the accumulation of 3-nitrotyrosine and 4-hydroxy-2-nonenal, was significantly increased along with significantly decreased expression of Nrf2 and its downstream antioxidants (NQO-1 and catalase. This was also exacerbated by zinc deficiency in the db/db mouse heart. These results suggested that zinc deficiency promotes the development and progression of DCM in T2DM db/db mice. The exacerbated effects by zinc deficiency on the heart of db/db mice may be related to further suppression of Nrf2 expression and function.

  4. Coronary angiography using synchrotron radiation

    International Nuclear Information System (INIS)

    Akatsuka, Takao; Hiranaka, Yukio; Takeda, Tohru; Hyodo, Kazuyuki.

    1990-01-01

    Invasive coronary angiography is the imaging technique of choice for diagnosis of ischemic heart disease. Recently, the application of synchrotron radiation in coronary angiography has been investigated in the world, with the aim of developing the noninvasive technique for visualizing the heart. In this article, backgrounds and present situation of coronary angiography using synchrotron radiation are reviewed. Firstly, visual imaging techniques of the cardiovascular system are discussed in terms of angiography and digital subtraction angiography (DSA). Conventional temporal, energy, and hybrid subtraction modes used in DSA are referred to. Secondly, the application of synchrotron radiation is presented, focusing on the property of synchrotron radiation and K-edge subtraction angiography. Two kinds of synchrotron radiation beam methods are outlined. Interpretation of image data and various subtraction procedures remain unestablished. There is much to be done before coronary angiography using synchrotron radiation comes into a clinical practice. (N.K.)

  5. Development of a Three-dimensional Surgical Navigation System with Magnetic Resonance Angiography and a Three-dimensional Printer for Robot-assisted Radical Prostatectomy.

    Science.gov (United States)

    Jomoto, Wataru; Tanooka, Masao; Doi, Hiroshi; Kikuchi, Keisuke; Mitsuie, Chiemi; Yamada, Yusuke; Suzuki, Toru; Yamano, Toshiko; Ishikura, Reiichi; Kotoura, Noriko; Yamamoto, Shingo

    2018-01-02

    We sought to develop a surgical navigation system using magnetic resonance angiography (MRA) and a three-dimensional (3D) printer for robot-assisted radical prostatectomy (RARP). Six patients with pathologically proven localized prostate cancer were prospectively enrolled in this study. Prostate magnetic resonance imaging (MRI), consisting of T2-weighted sampling perfection with application-optimized contrasts using different flip-angle evolutions (SPACE) and true fast imaging with steady-state precession (true FISP), reconstructed by volume rendering, was followed by dynamic contrast-enhanced MRA performed with a volumetric interpolated breath-hold examination (VIBE) during intravenous bolus injection of gadobutrol. Images of arterial and venous phases were acquired over approximately 210 seconds. Selected images were sent to a workstation for generation of 3D volume-rendered images and standard triangulated language (STL) files for 3D print construction. The neurovascular bundles (NVBs) were found in sequence on non-contrast images. Accessory pudendal arteries (APAs) were found in all cases in the arterial phase of contrast enhancement but were ill-defined on non-contrast enhanced MRA. Dynamic contrast-enhanced MRA helped to detect APAs, suggesting that this 3D system using MRI will be useful in RARP.

  6. Ultrasonographic Characterization of the db/db Mouse: An Animal Model of Metabolic Abnormalities

    Directory of Open Access Journals (Sweden)

    Francesco Faita

    2018-01-01

    Full Text Available The availability of an animal model able to reliably mirror organ damage occurring in metabolic diseases is an urgent need. These models, mostly rodents, have not been fully characterized in terms of cardiovascular, renal, and hepatic ultrasound parameters, and only sparse values can be found in literature. Aim of this paper is to provide a detailed, noninvasive description of the heart, vessels, liver, and kidneys of the db/db mouse by ultrasound imaging. Sixteen wild type and thirty-four db/db male mice (11-week-old were studied. State-of-the-art ultrasound technology was used to acquire images of cardiovascular, renal, and hepatic districts. A set of parameters describing function of the selected organs was evaluated. db/db mice are characterized by systolic and diastolic dysfunction, confirmed by strain analysis. Abdominal aortic and carotid stiffness do not seem to be increased in diabetic rodents; furthermore, they are characterized by a smaller mean diameter for both vessels. Renal microcirculation is significantly compromised, while liver steatosis is only slightly higher in db/db mice than in controls. We offer here for the first time an in vivo detailed ultrasonographic characterization of the db/db mouse, providing a useful tool for a thoughtful choice of the right rodent model for any experimental design.

  7. Coronary CT angiography

    Energy Technology Data Exchange (ETDEWEB)

    Dewey, Marc [Charite - Universitaetsmedizin Berlin (Germany). Inst. fuer Radiologie

    2009-07-01

    Coronary CT angiography has attained increasing scientific attention at academic institutions and has become a highly accurate diagnostic modality. Extending this knowledge into a practice setting is the purpose of 'Coronary CT Angiography'. This book will assist you in integrating cardiac CT into your daily practice, while also giving an overview of the current technical status and applications. The specific features of scanners from all four main vendors are also presented providing an objective overview of noninvasive coronary angiography using CT. (orig.)

  8. Angiography in angiology

    International Nuclear Information System (INIS)

    Zeitler, E.; Grosse-Vorholt, R.

    1980-01-01

    A review is given of recent developments in angiography including advances in the equipment, in the technique and in image processing. Indications for and interpretation of angiography are discussed and angiographic-therapeutic procedures are considered. (C.F.)

  9. Magnetic resonance angiography in renal grafts. Comparison with color Doppler echography

    International Nuclear Information System (INIS)

    Yanagisawa, Takayoshi; Otsubo, Osamu; Nozaki, Harushige

    1995-01-01

    We studied relationship between magnetic resonance angiography (MRA) of renal graft and renal graft function in 14 renal transplantations (10 from living donors, 4 from cadaveric donors). MRA was performed on 0.3-T permanent magnet system (MRP 7000, HITACHI, JAPAN) using 2 dimensional time of flight technique (FOV: 350 mm 2 , RT: 60 msec, ET: 10 msec, FA: 90deg, Slice: volumes 60, thickness 4 mm, overlap 1 mm). As for parameters of renal graft function, we evaluated color doppler echography (CD) of transplanted renal artery, renal blood flow (RBF), velocity of interlobar artery (ILA) and serum creatinine level (S-Cr). CD, RBF and velocity of ILA were visualized and measured by duplex color doppler echosystem (EUB-565A, HITACHI, JAPAN). Depending on visualization of transplanted renal artery, MRA was graded into 3 groups (MA Grade 3: visualization of ILA, MA Grade 2: visualization of segmental artery and the first branch but no visualization of ILA, MA Grade 1: visualization of main renal artery only). Likewise, visualization of CD was graded into 3 groups (CD Grade 3: good visualization of arcuate artery (AA) and ILA, CD Grade 2: poor visualization of AA but good visualization of ILA, CD Grade 1: poor visualization of ILA). The MRA grading had a very significant correlation (r=0.79, p<0.001) with the CD grading. As for RBF and velocity of ILA, the RBF of MA Grade 3 group (n=8) was significantly (p<0.05) higher than the MA Grade 2 group (n=4) and the MA Grade 1 group (n=2), and the velocity of ILA of MA Grade 3 group was also higher than the above groups but not significantly. Furthermore, the S-Cr of MA Grade 3 was significantly (p<0.05) lower than the others. These results showed that MRA of renal graft had a qualitative index of renal graft function. (author)

  10. Instant InnoDB

    CERN Document Server

    Reid, Matt

    2013-01-01

    This book is a complete reference guide, designed to provide you with answers and solutions to all the common problems you encounter within InnoDB, helping you achieve higher performance and greater stability in your InnoDB databases.The ""InnoDB Quick Reference Guide"" features content for all skill levels of MySQL administrators, developers, and engineers.

  11. Magnetic resonance angiography and tomography of vertebrobasilar dissections; Magnetresonanzangiographie und Magnetresonanztomographie bei Dissektionen der A. vertebralis

    Energy Technology Data Exchange (ETDEWEB)

    Felber, S. [Inst. fuer Magnetresonanztomographie und Spektroskopie, Universitaetskliniken Innsbruck (Austria)]|[Universitaetsklinik fuer Radiologie, Klinische Abt. 2, Universitaetskliniken Innsbruck (Austria); Auer, A. [Inst. fuer Magnetresonanztomographie und Spektroskopie, Universitaetskliniken Innsbruck (Austria); Schmidauer, C. [Universitaetsklinik fuer Neurologie, Universitaetskliniken Innsbruck (Austria); Waldenberger, P. [Universitaetsklinik fuer Radiologie, Klinische Abt. 1, Universitaetskliniken Innsbruck (Austria); Aichner, F. [Inst. fuer Magnetresonanztomographie und Spektroskopie, Universitaetskliniken Innsbruck (Austria)

    1996-11-01

    We retrospectively analyzed the role of MRT and MR angiography (MRA) in the detection of dissections of the vertebral artery. Between 1989 and 1995 we identified 24 patients with a vertebral artery dissection and 1 patient with a basilar artery dissection. The diagnosis of VAD was established by specific arteriographical findings (DSA) or clinical and neuroradiological course. All patients underwent a combined MRT/MRA examination protocol at 1.5 T that consisted of spin-echo imaging and time of flight MRA of the intra- and extracranial arteries using 2D Flash and 3D Fisp sequences. The MRT/MRA findings were correlated to DSA and ultrasound results. During the acute and subacute stage, MRT/MRA revealed abnormal findings in 21 of 22 dissected vessels (95.5%). There was one false-negative MRT/MRA in a patient with a V1 dissection. In 7/22 VAD the MRT/MRA findings were rated specific. DAS was sensitivie in 100% and ultrasound in 77.3%. Specific results were obtained by DSA in 8/22 VAD (36.4%) and in 7/22 VAD (30.4%) by MRT/MRA. When MRT/MRA and DSA results were combined, the specific findings increased to 43.5%. Follow-up examinations revealed recanalization in 52% of initially stenosed or occluded vertebral arteries. With this retrospective approach, we were able to show a high sensitivity of MRT/MRA for the presence of disturbed flow in the dissected vertebral artery. The MRA projections tended to overestimate stenosis and were inferior to DSA in the appreciation of irregularities of the vessel wall. Identification of high-grade stenosis, especially in the presence of distal occlusion, was improved on the MRA source images. The differentiation between luminal thrombus and mural hematoma requires interpretation of MRA source images, together with flow compensated spinecho images. There is a complementary role of MRT/MRA and DSA for an improved overall specificity for vertebral artery dissection. (orig./MG) [Deutsch] Dissektionen der hirnversorgenden Arterien sind eine

  12. High-resolution magnetic resonance angiography of the lower extremities with a dedicated 36-element matrix coil at 3 Tesla.

    Science.gov (United States)

    Kramer, Harald; Michaely, Henrik J; Matschl, Volker; Schmitt, Peter; Reiser, Maximilian F; Schoenberg, Stefan O

    2007-06-01

    Recent developments in hard- and software help to significantly increase image quality of magnetic resonance angiography (MRA). Parallel acquisition techniques (PAT) help to increase spatial resolution and to decrease acquisition time but also suffer from a decrease in signal-to-noise ratio (SNR). The movement to higher field strength and the use of dedicated angiography coils can further increase spatial resolution while decreasing acquisition times at the same SNR as it is known from contemporary exams. The goal of our study was to compare the image quality of MRA datasets acquired with a standard matrix coil in comparison to MRA datasets acquired with a dedicated peripheral angio matrix coil and higher factors of parallel imaging. Before the first volunteer examination, unaccelerated phantom measurements were performed with the different coils. After institutional review board approval, 15 healthy volunteers underwent MRA of the lower extremity on a 32 channel 3.0 Tesla MR System. In 5 of them MRA of the calves was performed with a PAT acceleration factor of 2 and a standard body-matrix surface coil placed at the legs. Ten volunteers underwent MRA of the calves with a dedicated 36-element angiography matrix coil: 5 with a PAT acceleration of 3 and 5 with a PAT acceleration factor of 4, respectively. The acquired volume and acquisition time was approximately the same in all examinations, only the spatial resolution was increased with the acceleration factor. The acquisition time per voxel was calculated. Image quality was rated independently by 2 readers in terms of vessel conspicuity, venous overlay, and occurrence of artifacts. The inter-reader agreement was calculated by the kappa-statistics. SNR and contrast-to-noise ratios from the different examinations were evaluated. All 15 volunteers completed the examination, no adverse events occurred. None of the examinations showed venous overlay; 70% of the examinations showed an excellent vessel conspicuity

  13. Identification of arteries and veins in cerebral angiography fluoroscopic images

    Science.gov (United States)

    Andra Tache, Irina

    2017-11-01

    In the present study a new method for pixels tagging into arteries and veins classes from temporal cerebral angiography is presented. This need comes from the neurosurgeon who is evaluating the fluoroscopic angiography and the magnetic resonance images from the brain in order to locate the fistula of the patients who suffer from arterio-venous malformation. The method includes the elimination of the background pixels from a previous segmentation and the generation of the time intensity curves for each remaining pixel. The later undergo signal processing in order to extract the characteristic parameters needed for applying the k-means clustering algorithm. Some of the parameters are: the phase and the maximum amplitude extracted from the Fourier transform, the standard deviation and the mean value. The tagged classes are represented into images which then are re-classified by an expert into artery and vein pixels.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-07-01

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

  15. MongoDB high availability

    CERN Document Server

    Mehrabani, Afshin

    2014-01-01

    This book has a perfect balance of concepts and their practical implementation along with solutions to make a highly available MongoDB server with clear instructions and guidance. If you are using MongoDB in a production environment and need a solution to make a highly available MongoDB server, this book is ideal for you. Familiarity with MongoDB is expected so that you understand the content of this book.

  16. Elevated Steroid Hormone Production in the db/db Mouse Model of Obesity and Type 2 Diabetes.

    Science.gov (United States)

    Hofmann, Anja; Peitzsch, Mirko; Brunssen, Coy; Mittag, Jennifer; Jannasch, Annett; Frenzel, Annika; Brown, Nicholas; Weldon, Steven M; Eisenhofer, Graeme; Bornstein, Stefan R; Morawietz, Henning

    2017-01-01

    Obesity and type 2 diabetes have become a major public health problem worldwide. Steroid hormone dysfunction appears to be linked to development of obesity and type 2 diabetes and correction of steroid abnormalities may offer new approaches to therapy. We therefore analyzed plasma steroids in 15-16 week old obese and diabetic db/db mice using liquid chromatography-tandem mass spectrometry. Lean db/+ served as controls. Db/db mice developed obesity, hyperglycemia, hyperleptinemia, and hyperlipidemia. Hepatic triglyceride storage was increased and adiponectin and pancreatic insulin were lowered. Aldosterone, corticosterone, 11-deoxycorticosterone, and progesterone were respectively increased by 3.6-, 2.9-, 3.4, and 1.7-fold in db/db mice compared to controls. Ratios of aldosterone-to-progesterone and corticosterone-to-progesterone were respectively 2.0- and 1.5-fold higher in db/db mice. Genes associated with steroidogenesis were quantified in the adrenal glands and gonadal adipose tissues. In adrenals, Cyp11b2 , Cyp11b1 , Cyp21a1 , Hsd3b1 , Cyp11a1 , and StAR were all significantly increased in db/db mice compared with db/+ controls. In adipose tissue, no Cyp11b2 or Cyp11b1 transcripts were detected and no differences in Cyp21a1 , Hsd3b1 , Cyp11a1 , or StAR expression were found between db/+ and db/db mice. In conclusion, the present study showed an elevated steroid hormone production and adrenal steroidogenesis in the db/db model of obesity and type 2 diabetes. © Georg Thieme Verlag KG Stuttgart · New York.

  17. MR imaging and MR angiography in popliteal artery entrapment syndrome

    International Nuclear Information System (INIS)

    Atilla, S.; Akpek, S.; Yuecel, C.; Tali, E.T.; Isik, S.; Ilgit, E.T.

    1998-01-01

    Popliteal artery entrapment (PAE) syndrome is an uncommon congenital anomaly seen in young adults causing ischemic symptoms in the lower extremities. It is the result of various types of anomalous relationships between the popliteal artery and the neighboring muscular structures. The purpose of this study was to define the role of MR imaging combined with MR angiography in the diagnosis of PAE cases. Four cases with segmental occlusion and medial displacement of popliteal artery in digital subtraction angiography (DSA) examinations were diagnosed as PAE syndrome by MR imaging and MR angiography. The DSA and MRA images are compared. All of the cases showed various degrees of abnormal intercondylar insertion of the medial head of the gastrocnemius muscle. The MR images showed detailed anatomy of the region revealing the cause of the arterial entrapment. Subclassification of the cases were done and fat tissue filling the normal localization of the muscle was evaluated. The DSA and MRA images demonstrated the length and localization of the occluded segment and collateral vascular developments equally. It is concluded that angiographic evaluation alone in PAE syndrome might result in overlooking the underlying cause of the arterial occlusion, which in turn leads to unsuccessful therapy procedures such as balloon angioplasty. Magnetic resonance imaging combined with MR angiography demonstrates both the vascular anatomy and the variations in the muscular structures in the popliteal fossa successfully, and this combination seems to be the most effective way of evaluating young adults with ischemic symptoms suggesting PAE syndrome. (orig.)

  18. Preoperative evaluation of living renal donors: value of contrast-enhanced 3D magnetic resonance angiography and comparison of three rendering algorithms

    Energy Technology Data Exchange (ETDEWEB)

    Fink, C. [Abteilung Radiologische Diagnostik, Radiologische Universitaetsklinik Heidelberg, Im Neuenheimer Feld 110, 69120 Heidelberg (Germany); Abteilung Onkologische Diagnostik und Therapie, Forschungsschwerpunkt Radiologische Diagnostik und Therapie, Deutsches Krebsforschungszentrum, Im Neuenheimer Feld 280, 69120 Heidelberg (Germany); Hallscheidt, P.J.; Hosch, W.P.; Kauffmann, G.W.; Duex, M. [Abteilung Radiologische Diagnostik, Radiologische Universitaetsklinik Heidelberg, Im Neuenheimer Feld 110, 69120 Heidelberg (Germany); Ott, R.C.; Wiesel, M. [Abteilung Urologie und Poliklinik, Chirurgische Universitaetsklinik Heidelberg, Im Neuenheimer Feld 110, 69120 Heidelberg (Germany)

    2003-04-01

    The aim of this study was to assess the value of contrast-enhanced three-dimensional MR angiography (CE 3D MRA) in the preoperative assessment of potential living renal donors, and to compare the accuracy for the depiction of the vascular anatomy using three different rendering algorithms. Twenty-three potential living renal donors were examined with CE 3D MRA (TE/TR=1.3 ms/3.7 ms, field of view 260-320 x 350 mm, 384-448 x 512 matrix, slab thickness 9.4 cm, 72 partitions, section thickness 1.3 mm, scan time 24 s, 0.1 mmol/kg body weight gadobenate dimeglumine). Magnetic resonance angiography data sets were processed with maximum intensity projection (MIP), volume rendering (VR), and shaded-surface display (SSD) algorithms. The image analysis was performed independently by three MR-experienced radiologists recording the number of renal arteries, the presence of early branching or vascular pathology. The combination of digital subtraction angiography (DSA) and intraoperative findings served as the gold standard for the image analysis. In total, 52 renal arteries were correspondingly observed in 23 patients at DSA and surgery. Other findings were 3 cases of early branching of the renal arteries, 4 cases of arterial stenosis and 1 case of bilateral fibromuscular dysplasia. With MRA source data all 52 renal arteries were correctly identified by all readers, compared with 51 (98.1%), 51-52 (98.1-100%) and 49-50 renal arteries (94.2-96.2%) with the MIP, VR and SSD projections, respectively. Similarly, the sensitivity, specificity and accuracy was highest with the MRA source data followed by MIP, VR and SSD. Time requirements were lowest for the MIP reconstructions and highest for the VR reconstructions. Contrast-enhanced 3D MRA is a reliable, non-invasive tool for the preoperative evaluation of potential living renal donors. Maximum intensity projection is favourable for the processing of 3D MRA data, as it has minimal time and computational requirements, while having

  19. Preoperative evaluation of living renal donors: value of contrast-enhanced 3D magnetic resonance angiography and comparison of three rendering algorithms

    International Nuclear Information System (INIS)

    Fink, C.; Hallscheidt, P.J.; Hosch, W.P.; Kauffmann, G.W.; Duex, M.; Ott, R.C.; Wiesel, M.

    2003-01-01

    The aim of this study was to assess the value of contrast-enhanced three-dimensional MR angiography (CE 3D MRA) in the preoperative assessment of potential living renal donors, and to compare the accuracy for the depiction of the vascular anatomy using three different rendering algorithms. Twenty-three potential living renal donors were examined with CE 3D MRA (TE/TR=1.3 ms/3.7 ms, field of view 260-320 x 350 mm, 384-448 x 512 matrix, slab thickness 9.4 cm, 72 partitions, section thickness 1.3 mm, scan time 24 s, 0.1 mmol/kg body weight gadobenate dimeglumine). Magnetic resonance angiography data sets were processed with maximum intensity projection (MIP), volume rendering (VR), and shaded-surface display (SSD) algorithms. The image analysis was performed independently by three MR-experienced radiologists recording the number of renal arteries, the presence of early branching or vascular pathology. The combination of digital subtraction angiography (DSA) and intraoperative findings served as the gold standard for the image analysis. In total, 52 renal arteries were correspondingly observed in 23 patients at DSA and surgery. Other findings were 3 cases of early branching of the renal arteries, 4 cases of arterial stenosis and 1 case of bilateral fibromuscular dysplasia. With MRA source data all 52 renal arteries were correctly identified by all readers, compared with 51 (98.1%), 51-52 (98.1-100%) and 49-50 renal arteries (94.2-96.2%) with the MIP, VR and SSD projections, respectively. Similarly, the sensitivity, specificity and accuracy was highest with the MRA source data followed by MIP, VR and SSD. Time requirements were lowest for the MIP reconstructions and highest for the VR reconstructions. Contrast-enhanced 3D MRA is a reliable, non-invasive tool for the preoperative evaluation of potential living renal donors. Maximum intensity projection is favourable for the processing of 3D MRA data, as it has minimal time and computational requirements, while having

  20. Protective effects of astragaloside IV on db/db mice with diabetic retinopathy.

    Directory of Open Access Journals (Sweden)

    Yuzhi Ding

    Full Text Available Diabetic retinopathy (DR is a common diabetic eye disease which is well-known as the result of microvascular retinal changes. Although the potential biological functions of astragaloside IV (AS IV have long been described in traditional system of medicine, its protective effect on DR remains unclear. This study aims to investigate the function and mechanism of AS IV on type 2 diabetic db/db mice.Db/db mice were treated with AS IV (4.5 mg/kg or 9 mg/kg or physiological saline by oral gavage for 20 weeks along with db/m mice. In each group, retinal ganglion cell (RGC function was measured by pattern electroretinogram (ERG and apoptosis was determined by Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL staining. Blood and retina aldose reductase (AR activity were quantified by chemiluminescence analysis. The expressions of phosporylated-ERK1/2, NF-κB were determined by Western blot analysis. Furthermore, the expression of related downstream proteins were quantified by Label-based Mouse Antibody Array.Administration of AS IV significantly improved the amplitude in pattern ERG and reduced the apoptosis of RGCs.in db/db mice. Furthermore, downregulation of AR activity, ERK1/2 phosphorylation, NF-κB and related cytokine were observed in AS IV treatment group.Our study indicated that AS IV, as an inhibitor of AR, could prevent the activation of ERK1/2 phosporylation and NF-kB and further relieve the RGCs disfunction in db/db mice with DR. It has provided a basis for investigating the clinical efficacy of AR inhibitors in preventing DR.

  1. Noncontrast-enhanced magnetic resonance renal angiography using a repetitive artery and venous labelling technique at 3 T: comparison with contrast-enhanced magnetic resonance angiography in subjects with normal renal function

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sung Yoon [Sungkyunkwan University School of Medicine, Department of Radiology and Center for Imaging Science, Samsung Medical Center, Seoul (Korea, Republic of); Severance Hospital, Yonsei University College of Medicine, Department of Radiology and Research Institute of Radiological Science, Seoul (Korea, Republic of); Kim, Chan Kyo; Park, Byung Kwan [Sungkyunkwan University School of Medicine, Department of Radiology and Center for Imaging Science, Samsung Medical Center, Seoul (Korea, Republic of); Kim, EunJu [Philips Healthcare Korea, Seoul (Korea, Republic of)

    2014-09-13

    To investigate the feasibility of noncontrast-enhanced MR angiography (NC-MRA) using the repetitive artery and venous labelling (RAVEL) technique to evaluate renal arteries compared to contrast-enhanced MR angiography (CE-MRA). Twenty-five subjects with normal renal function underwent NC-MRA using a RAVEL technique and CE-MRA at 3 T. Two independent readers analysed the MRA images. Image quality, number of renal arteries, presence or absence of an early branching vessel, and diameter of the main renal arteries were evaluated. The overall image quality of NC-MRA was fair or greater in 88 % of right and 92 % of left renal arteries, while it was 96 % in both sides with CE-MRA. On NC-MRA, the number of renal arteries in all subjects was perfectly predicted by both readers. Sensitivity and specificity for predicting early branching vessels were 82 % and 100 % for reader 1 and 82 % and 95 % for reader 2. Inter-modality agreement for comparing the diameters of main renal arteries was good or excellent at all segments for both readers. Inter-reader agreement was moderate or good at all segments except at the right distal segment on NC-MRA. NC-MRA with the RAVEL technique at 3 T may have comparable diagnostic feasibility for evaluating renal arteries compared to CE-MRA. (orig.)

  2. Angiography - interventional diagnostic applications

    International Nuclear Information System (INIS)

    Schild, H.

    1994-01-01

    The angiography system is very different from the other systems used in diagnostic radiology. The invasivity of angiography requires special, high standards in theoretical and practical training and experience both of beginners and experienced personnel. This textbook fully meets the demand for in-depth and exhaustive information, as it presents: - The fundamentals and techniques of angiography, the vascular anatomy, and many hints and tips of great help in practice. - A comprehensive survey of diagnostic problems and examination approaches, including neuro-angiography, with 221 reproductions of original angiographs, and additional schematic representations. - A special chapter devoted to indication and relevant techniques for the major vascular interventional examinations. - A great number of tables explain at a glance standard examination techniques, indications and diagnostic criteria. (orig./CB) [de

  3. Exendin-4 improves resistance to Listeria monocytogenes infection in diabetic db/db mice

    OpenAIRE

    Liu, Hsien Yueh; Chung, Chih-Yao; Yang, Wen-Chin; Liang, Chih-Lung; Wang, Chi-Young; Chang, Chih-Yu; Chang, Cicero Lee-Tian

    2012-01-01

    The incidence of diabetes mellitus is increasing among companion animals. This disease has similar characteristics in both humans and animals. Diabetes is frequently identified as an independent risk factor for infections associated with increased mortality. In the present study, homozygous diabetic (db/db) mice were infected with Listeria (L.) monocytogenes and then treated with the anti-diabetic drug exendin-4, a glucagon-like peptide 1 analogue. In aged db/db mice, decreased CD11b+ macroph...

  4. Craniofacial duplication (diprosopus): CT, MR imaging, and MR angiography findings case report.

    Science.gov (United States)

    Hähnel, Stefan; Schramm, Peter; Hassfeld, Stefan; Steiner, Hans H; Seitz, Angelika

    2003-01-01

    Diprosopus is one of the rarest malformations in humans. In addition to the facial structures, the cerebral frontal lobes were duplicated in this case. Three pairs of anterior cerebral arteries were detected, and the rostral parts of the superior sagittal sinus were duplicated. Computed tomography, magnetic resonance (MR) imaging, and MR angiography allowed study of the degree of duplicative changes in diprosopus, especially for planning cosmetic correction. Copyright RSNA, 2002

  5. Comparison of MR angiography with conventional angiography in cervical and intracranial vascular disease

    International Nuclear Information System (INIS)

    Choi, D. S.; Chang, K. H.; Jung, H. W.; Han, M. H.

    1995-01-01

    To assess the usefulness of magnetic resonance angiography (MRA) in evaluation of stenosis of carotid and large cerebral vessels and cerebral aneurysm. Twenty-seven patients with either arterial stenosis in cervical or intracranial major vessels (n = 18) or cerebral aneurysm (n = 8) or both (n 1) were examined with both MRA and conventional angiography (CA). MRA was performed with 3D TOF technique with magnetization transfer suppression at 1.5T system (Magnetom, Siemens, Germany); both intracranial MRA and cervical MRA in 16 patients, intracranial MRA only in the remaining patients. For evaluation of arterial stenosis, 32 carotid bifurcations and 383 segments of intracranial major vessels were assessed in blind fashion, and were compared with those of CA. Each arterial segment was arbitrarily classified into one of five grades (< 10, 10-49, 50-74, 75-99, 100%) for carotid bifurcation and one of four (< 10, 10-49, 50-99, 100%) for intracranial vessels. For aneurysm, its location, size shape and direction were compared. For arterial stenosis, concordance rate between MRA and CA was 88% (28/32) in carotid bifurcation and 89% (340/383) in intracranial vessels. All discordant cases were overgraded on MRA. For aneurysm, 7 of 9 were demonstrated on both MRA and CA, one of which was partially demonstrated on MRA. One of the other two patients showed aneurysm only on MRA, whereas the remaining one revealed aneurysm only on CA. MRA may be performed as a screening test for occlusive disease of cervical and major intracranial vessels and cerebral aneurysm

  6. Basalt aquifer identification, correlation and sampling activities. History of Wells DB-8, DB-9, DB-10 and DB-11

    International Nuclear Information System (INIS)

    Webster, C.T.

    1979-07-01

    Research core wells have been completed to assist in the characterization of the groundwater regime of the upper confined aquifers found within the basalts of the Hanford Site. These wells were drilled on the Hanford Site for the Long-Term Transuranic Defense Waste Program. They were constructed to assure the Department of Energy that waste management operations will not provide an avenue for offsite migration of radionuclides. This second report details results of confined aquifer drilling activities. The purpose of this report is to document the drilling history of the wells by presenting as-built well construction diagrams and tables listing hole history data, coring records and bit records. Four wells were cored to a maximum depth of 1100 feet and water samples were taken from selected confined aquifers. Full depth was reached on all wells and core recovery was 94% of all formations drilled. Well DB-8 was abandoned after a well screen was destroyed while setting it in the well. Two wells, DB-9 and DB-10 were screened in the Mabton interbed and water was produced from this interval in both wells. Well DB-11 was used to explore for artesian water from the Priest Rapids flow unit on the western edge of the Hanford Site. The water was found at a depth of 1045 feet and now produces makeup water for all Hanford drilling

  7. Efficacy of Acetylshikonin in Preventing Obesity and Hepatic Steatosis in db/db Mice

    Directory of Open Access Journals (Sweden)

    Mei-Ling Su

    2016-07-01

    Full Text Available Zicao (Lithospermum erythrorhizon has been used in clinics as a traditional Chinese medicine for thousands of years. Acetylshikonin (AS is the main ingredient of Zicao, Xinjiang, China. The objective of this study was to investigate the anti-obesity and anti-nonalcoholic fatty liver disease (NAFLD efficacy of AS in a model of spontaneous obese db/db mice. Mice were divided into Wild Type (WT groups and db/db groups, which received no treatment or treatment with 100 mg/kg/day clenbuterol (CL hydrochloride or 540 mg/kg/day AS by oral gavage for eight weeks. The results provided the evidence that AS prevented obesity and NAFLD including reduction in body weight, food efficiency ratio, serum triglyceride (TG and free fatty acid (FFA levels in db/db mice. Administration of AS markedly suppressed the levels of hepatic alanine aminotransferase (ALT, aspartate aminotransferase (AST and pro-inflammatory cytokines in treated groups when compared with that of db/db groups. Further investigation of the lipid synthesis-related protein using Western blotting revealed that hepatic protein expression of sterol regulatory element-binding protein-1 (SREBP-1, fatty acid synthetase (FAS and 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR were significantly downregulated by AS treatment. These findings suggest that AS exerts anti-obesity and anti-NAFLD effects through the regulation of lipid metabolism and anti-inflammatory effects.

  8. The role of preoperative cerebral magnetic resonance angiography in the prevention of cerebral complications following cardiovascular surgery

    Energy Technology Data Exchange (ETDEWEB)

    Abe, Masakazu; Sakai, Akira; Kodera, Koujirou; Sudo, Kyouichi; Oosawa, Mikio [Seirei Hamamatsu General Hospital, Shizuoka (Japan)

    1997-11-01

    Screening of carotid and intracranial artery diseases by magnetic resonance angiography (MRA) was performed in forty-one adult patients prior to elective cardiovascular surgery. In twenty patients (48.8%), MRA demonstrated significant cerebrovascular lesions: carotid or main cerebral artery stenosis in 7, diffuse cerebral arteriosclerotic change in 6, vertebral artery lesion in 5 and berry aneurysm in 2. Advanced age (over 70 years) and previous cerebrovascular events increased the incidence of cerebrovascular lesions on MRA. Forty patients underwent scheduled surgery under cardiopulmonary bypass, and pulsatile flow perfusion was used in patients in whom significant cerebrovascular lesions were demonstrated on MRA. One patient with aortic arch aneurysm was judged to be an unacceptable candidate for surgery in light of his marked diffuse arteriosclerotic lesions on MRA. In five patients, staged operation was performed from 10 to 30 days after cerebrovascular surgery (bypass surgery for internal carotid occlusion in 2, aneurysm clipping in 2, carotid endarterectomy in 1). Postoperative neurological complications occurred in one patient (2.5%). In conclusion, screening of carotid and intracranial artery diseases by MRA is a safe and useful method for evaluation of cerebrovascular lesions in patients with advanced age, previous cerebrovascular events and/or arteriosclerotic diseases. (author)

  9. Alkannin Inhibited Hepatic Inflammation in Diabetic Db/Db Mice

    Directory of Open Access Journals (Sweden)

    Wenhua Xue

    2018-03-01

    Full Text Available Background/Aims: The current study was designed to investigate the protective role of alkannin (ALK on liver injury in diabetic C57BL/KsJ-db/db mice and explore its potential mechanisms. Methods: An oral glucose tolerance test (OGTT was performed. The levels of insulin, alanine aminotransferase (ALT, aspartate aminotransaminase (AST, total cholesterol (TC and triglyceride (TG were determined by commercial kits. The pro-inflammatory cytokines interleukin (IL-1β, IL-6 and tumour necrosis factor (TNF-α were determined by ELISA. The levels of the ROCK/NF-κB pathway were determined by Western blotting. Results: The contents of pro-inflammatory cytokines interleukin (IL-1β, IL-6 and tumour necrosis factor (TNF-α were inhibited by ALK, metformin or fasudil in diabetic db/db mice. Further, Western blotting analysis showed that the expression of Rho, ROCK1, ROCK2, p-NF-κBp65, and p-IκBα was significantly reversed by ALK treatment. In human hepatic HepG2 cells, the hepatoprotective effects of ALK were further characterized. With response to palmitic acid-challenge, increased amounts of insulin, ALT, AST, TG, and TC were observed, whereas ALK pretreatment significantly inhibited their leakage in HepG2 cells without appreciable cytotoxic effects. The inflammation condition was recovered with ALK treatment as shown by changes of IL-1β, IL-6 and TNF-α. Further, Western blotting analysis also suggested that ALK improves hepatic inflammation in a Rho-kinase pathway. Conclusion: The present study successfully investigated the role of Rho-kinase signalling in diabetic liver injury. ALK exhibited hepatoprotective effects in diabetic db/db mice, and it might act through improving hepatic inflammation through the Rho-kinase pathway.

  10. Gadofosveset trisodium-enhanced magnetic resonance angiography of the left atrium-A feasibility study

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, Moritz, E-mail: moritz.wagner@charite.d [Department of Radiology, Charite - University Hospital, Berlin (Germany); Rief, Matthias; Asbach, Patrick [Department of Radiology, Charite - University Hospital, Berlin (Germany); Vogtmann, Thomas [Department of Cardioloy and Angiology, Charite - University Hospital, Berlin (Germany); Huppertz, Alexander [Imaging Science Institute Charite Berlin, Berlin (Germany); Beling, Mark [Department of Cardioloy and Angiology, Charite - University Hospital, Berlin (Germany); Butler, Craig [Mazankowski Alberta Heart Institute, University of Alberta, Edmonton (Canada); Laule, Michael [Department of Cardioloy and Angiology, Charite - University Hospital, Berlin (Germany); Warmuth, Carsten; Taupitz, Matthias; Hamm, Bernd; Lembcke, Alexander [Department of Radiology, Charite - University Hospital, Berlin (Germany)

    2010-08-15

    Aim: Imaging of the left atrium is regularly performed prior to pulmonary vein isolation. The aim of the study was to evaluate the feasibility of contrast-enhanced high-resolution magnetic resonance angiography (MRA) of the left atrium using the blood-pool contrast agent gadofosveset trisodium in comparison to noncontrast MRA. Materials and methods: Twenty consecutive patients were examined by free-breathing electrocardiogram-gated whole-heart MRA (reconstructed spatial resolution, 0.7 mm x 0.6 mm x 0.8 mm) with a noncontrast T2-prepared steady state free precession sequence (T2-prep SSFP) and a gadofosveset trisodium-enhanced inversion-recovery SSFP sequence (CE IR-SSFP). Contrast-to-noise ratio (CNR) of blood in the left atrium was determined. Depiction of the left atrium was rated by two radiologists in consensus. A cardiologist segmented the MR data sets and rated depiction of the left atrium. Results: Five of 20 patients had irregular breathing patterns with navigator efficiency less than 35% and were excluded from evaluation. CNR was significantly higher for CE IR-SSFP compared with T2-prep SSFP (18.4 {+-} 5.3 vs. 11.7 {+-} 3.5, p < 0.01). Depiction of the left atrium by T2-prep SSFP was rated as good in four patients, moderate in ten patients, and poor in one patient, whereas depiction of the left atrium by CE IR-SSFP was rated as excellent in nine patients, good in four patients, and moderate in two patients. CE IR-SSFP allowed for semiautomated segmentation of the left atrium in 15 patients, whereas T2-prep SSFP allowed for segmentation only in ten patients. Conclusion: Gadofosveset trisodium-enhanced MRA of the left atrium is feasible with significantly improved image quality compared to noncontrast MRA.

  11. Evaluation of the pedal artery: comparison of three-dimensional gadolinium-enhanced MR angiography with digital subtraction angiography

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jeong Min; Kang, Sung Gwon; Byun, Joo Nam; Kim, Young Cheol; Choi, Jeong Yeol; Kim, Dong Hyun [College of Medicine, Chosun Univ., Kwangju (Korea, Republic of)

    2002-07-01

    To compare the three-dimensional gadolinium-enhanced MR angiography with digital subtraction angiography (DSA) for evaluation of the pedal artery. In 12 extremities of 11 patients, both digital subtraction angiography (DSA) and contrast-enhanced MR angiography (CE-MR angiography) were performed during the same week. Among ten of the 11 patients, the following conditions were present: atherosclerosis (n=4), diabetic foot (n=3), Buerger's disease (n=1), calciphylactic arteriopathy (n=1) and arteriovenous malformation of the foot (n=1). The remaining patient underwent angiography prior to flap surgery. For MR angiography, a 1.5T system using an extremity or head coil was used. A three-dimensional FISP (fast imaging with steady state precession) sequence was obtained before enhancement, followed by four sequential acquisitions (scan time, 20 secs, scan interval time, 10 secs) 10 seconds after intravenous bolus injection of normal saline (total 10 cc), following intravenous administration of gadolinium (0.02 mmol/kg, 3 ml/sec). Arterial segments of the ankle and foot were classified as the anterior or posterior tibial artery, the distal peroneal artery, the medial or lateral plantar artery, the pedal arch, and the dorsalis pedis artery. Two radiologists independently analysed visualization of each arteraial segment and the mean of visible arterial segments in one extreminty using CE-MR angiography and DSA. Among 84 arterial segments, 16 were invisible at both CE-MR angiography and DSA, while 39 were demonstrated by both modalities. Twenty-six segments were visible only at CE-MR angiography and three only at DSA. CE-MR angiography displayed a higher number of arterial segments than DSA (mean, 5.42 vs. mean 3.50, respectively), a difference which was statistically significant (p<0.000). The difference between each arterial segment was not statistically significant, except for the dorsalis pedis artery (t test, p<0.000). In that it provides additional information for

  12. Validity of leptin receptor-deficiency (db/db) type 2 diabetes mellitus mice as a model of secondary osteoporosis

    Science.gov (United States)

    Huang, Le; You, Yong-Ke; Zhu, Tracy Y.; Zheng, Li-Zhen; Huang, Xiao-Ru; Chen, Hai-Yong; Yao, Dong; Lan, Hui-Yao; Qin, Ling

    2016-06-01

    This study aimed to evaluate the validation of the leptin receptor-deficient mice model for secondary osteoporosis associated with type 2 diabetes mellitus (T2DM) at bone micro-architectural level. Thirty three 36-week old male mice were divided into four groups: normal control (db/m) (n = 7), leptin receptor-deficient T2DM (db/db) (n = 8), human C-reactive protein (CRP) transgenic normal control (crp/db/m) (n = 7), and human CRP transgenic T2DM (crp/db/db) (n = 11). Lumber vertebrae (L5) and bilateral lower limbs were scanned by micro-CT to analyze trabecular and cortical bone quality. Right femora were used for three-point bending to analyze the mechanical properties. Trabecular bone quality at L5 was better in db/db or crp/db/db group in terms of bone mineral density (BMD), bone volume fraction, connectivity density, trabecular number and separation (all p  0.05). Maximum loading and energy yield in mechanical test were similar among groups while the elastic modulus in db/db and crp/db/db significantly lower than db/m. The leptin-receptor mice is not a proper model for secondary osteoporosis associated with T2DM.

  13. External Ear Resonant Amplitude and Frequency of 3-7 Year Old Children

    Directory of Open Access Journals (Sweden)

    Amir Hossein Zare

    2004-06-01

    Full Text Available Objective: To measure external ear resonant amplitude and frequency in children (3-7 years old and to compare with adult measures. Method and materials: The external ear resonance peak amplitude and frequency of 63 children 3-7 years old were recorded. All of the children had normal tympanogram and there was no cerumen in external auditory canal. 20 adult of 21-24 years old (10 male , 10 female were selected in order to compare with children that had normal tympanogram. The tests included : 1-otoscopy 2- tympanometry 3-microphone probe tube test. Results: The average of resonance peak frequency for children and adult is 4200 Hz and 3200 Hz , respectively. The resonance frequency of children had significantly diffrence with average of resonance frequency in adults. The average of resonance peak amplitude for children and adult is 17.70 dB and 17.17 dB , respectively. Conclusion: Resonant frequency and amplitude affect the hearing aid prescription and fitting process and calculating insertion gain; so, this measures seem should be considered in children hearing aid fitting.

  14. Angiorressonância magnética do crânio: revisão de 100 casos Magnetic resonance angiography of the brain: review of 100 cases

    Directory of Open Access Journals (Sweden)

    Leonardo Portugal Guimarães Amaral

    2004-06-01

    Full Text Available Neste trabalho foram analisados, retrospectivamente, os exames de 100 pacientes que se submeteram a angiografia por ressonância magnética (angio-RM do crânio com diferentes indicações clínicas. Os objetivos deste trabalho foram discutir as vantagens e desvantagens da técnica 3D TOF em exames de angio-RM cerebral e verificar as principais indicações de angio-RM na avaliação das lesões vasculares intracranianas e a freqüência dos principais achados nestes exames. As principais indicações para a realização de angio-RM neste trabalho foram cefaléia (n = 29, acidente vascular encefálico (n = 14 e ataque isquêmico transitório (n = 11. Em 11 casos não havia indicação clínica e os demais tiveram indicações diversas. Cinqüenta e dois por cento dos exames apresentaram alguma alteração. Os principais achados foram estenose vascular (n = 30, aneurisma (n = 10, variações anatômicas (n = 6, malformações vasculares (n = 4 e trombose dos seios durais (n = 2. A técnica 3D TOF, única utilizada neste trabalho, mostrou-se eficiente na maioria dos casos, com um tempo relativamente curto para sua aquisição. Como desvantagem, não se mostra eficaz para cobrir grandes volumes.In this study we reviewed the scans of 100 patients submitted to magnetic resonance angiography (MR angiography of the brain for different clinical indications. The objectives of the study were to discuss the advantages and disadvantages of the 3D TOF in cerebral MR angiography, to review the main indications of MR angiography in the evaluation of intracranial vascular lesions, and to assess the frequency of the most important findings. The main indications for MR angiography were headache (n = 29, stroke (n = 14, transient ischemic attack (n = 11 and other causes (n = 35. In 11 patients the clinical indication could not be recovered from the patients records. Fifty two percent of the exams showed abnormalities. The main findings were vascular stenosis (n

  15. Interaction between adrenaline and dibenzo-18-crown-6: Electrochemical, nuclear magnetic resonance, and theoretical study

    Science.gov (United States)

    Yu, Zhang-Yu; Liu, Tao; Wang, Xue-Liang

    2014-12-01

    The interaction between adrenaline (Ad) and dibenzo-18-crown-6 (DB18C6) was studied by cyclic voltammetry, nuclear magnetic resonance spectroscopy, and the theoretical calculations, respectively. The results show that DB18C6 will affect the electron transfer properties of Ad. DB18C6 can form stable supramolecular complexes with Ad through ion-dipole and hydrogen bond interactions.

  16. Scaling CouchDB

    CERN Document Server

    Holt, Bradley

    2011-01-01

    This practical guide offers a short course on scaling CouchDB to meet the capacity needs of your distributed application. Through a series of scenario-based examples, this book lets you explore several methods for creating a system that can accommodate growth and meet expected demand. In the process, you learn about several tools that can help you with replication, load balancing, clustering, and load testing and monitoring. Apply performance tips for tuning your databaseReplicate data, using Futon and CouchDB's RESTful interfaceDistribute CouchDB's workload through load balancingLearn option

  17. 360° tunable microwave phase shifter based on silicon-on-insulator dual-microring resonator

    DEFF Research Database (Denmark)

    Pu, Minhao; Xue, Weiqi; Liu, Liu

    2010-01-01

    We demonstrate tunable microwave phase shifters based on electrically tunable silicon-on-insulator dual-microring resonators. A quasi-linear phase shift of 360° with ~2dB radio frequency power variation at a microwave frequency of 40GHz is obtained......We demonstrate tunable microwave phase shifters based on electrically tunable silicon-on-insulator dual-microring resonators. A quasi-linear phase shift of 360° with ~2dB radio frequency power variation at a microwave frequency of 40GHz is obtained...

  18. MR angiography (MRA)

    Energy Technology Data Exchange (ETDEWEB)

    Hasuo, Kanehiro [Kyushu Univ., Fukuoka (Japan). Faculty of Medicine

    1995-12-01

    The primary goal of vascular imaging is the visualization of morphology and hemodynamics. Catheter angiography has been regarded as a gold standard for this purpose. However, MR angiography (MRA) is now increasingly being recognized as an important noninvasive technique for the depiction of vascular diseases and is partially superseding catheter angiography. The author evaluated the usefulness of MRA in the diagnosis of cerebral aneurysms and moyamoya disease. All aneurysms 5 mm or larger in diameter could be detected and most of those less than 5 mm in diameter were also detectable with using a combination of MIP images, target MIP images and source images. In moyamoya disease, the diagnosis could be made in all. For hemodynamic changes, flow directions in the circle of Willis could be visualized by phase-contrast MRA in a normal volunteer. In addition, MRA successfully showed the patency of surgical collaterals in cases of moyamoya disease. Despite some limitations compared with catheter angiography, MRA has a high sensitivity and specificity in the diagnosis of cerebrovascular abnormalities. Furthermore, screening of cerebral aneurysms or cerebrovascular occlusive diseases seems to be a new, and important indication for MRA. (author).

  19. Risk of renal allograft rejection following angiography

    International Nuclear Information System (INIS)

    Heideman, M.; Claes, G.; Nilson, A.E.

    1976-01-01

    In a retrospective study of 173 immediately functioning primary kidney transplants, correlation between angiography and renal allograft rejection was studied during the first 14 days. It was found that rejection was more frequent in kidneys undergoing angiography than in those not undergoing angiography. It was also found that in kidneys undergoing angiography an overwhelming number of the rejections started the day after angiography. These differences in rejection frequency could not be explained by differences in HLA matching or the origin of the kidneys. These findings suggest a possible connection indicating that the angiography might elicit an acute rejection episode. A possible mechanism for starting this reaction might be activation of the complement system which was found in 50 percent of the patients undergoing angiography in peripheral blood and in 100 percent when studied in vitro

  20. Perivascular adipose tissue control of insulin-induced vasoreactivity in muscle is impaired in db/db mice

    DEFF Research Database (Denmark)

    Meijer, Rick I; Bakker, Wineke; Alta, Caro-Lynn A F

    2013-01-01

    in muscle, the underlying mechanisms, and how obesity disturbs this vasodilation. Insulin-induced vasoreactivity of resistance arteries was studied with PVAT from C57BL/6 or db/db mice. PVAT weight in muscle was higher in db/db mice compared with C57BL/6 mice. PVAT from C57BL/6 mice uncovered insulin......-induced vasodilation; this vasodilation was abrogated with PVAT from db/db mice. Blocking adiponectin abolished the vasodilator effect of insulin in the presence of C57BL/6 PVAT, and adiponectin secretion was lower in db/db PVAT. To investigate this interaction further, resistance arteries of AMPKa2(+/+) and AMPKa2......-induced vasodilation in an adiponectin-dependent manner. In conclusion, PVAT controls insulin-induced vasoreactivity in the muscle microcirculation through secretion of adiponectin and subsequent AMPKa2 signaling. PVAT from obese mice inhibits insulin-induced vasodilation, which can be restored by inhibition of JNK....

  1. Digital subtraction angiography in ischemic cerebrovascular accidents

    Energy Technology Data Exchange (ETDEWEB)

    Manelfe, C.; Bonafe, A.; Ducos de Lahitte, M.; Rascol, A.; Prere, J.; Guiraud, B.; Marc-Vergnes, J.P. (Hopital Purpan, 31 - Toulouse (France))

    1983-12-29

    Recent advances in computer and radiological technology have permitted reassessment of intravenous angiography in the evaluation of cerebrovascular disorders. Although digital subtraction angiography is a relatively new technique, it has rapidly gained a widespread acceptance. It has extended the use of angiography to outpatients and to people in whom conventional angiography is contraindicated. This reliable, safe, and relatively noninvasive technique offers the user two benefits: real-time subtraction and enhanced image quality. The system allows angiographic evaluation of the extracranial and intracranial vessels by means of intravenous injection of contrast material. Extracranial studies clearly demonstrate stenoses and occlusions of the major cervicocephalic arteries. Intracranial studies usually detect major cerebrovascular occlusions and provide insight into the collateral flow patterns. Intravenous digital subtraction angiography permits accurate assessment of cervicocephalic vessels after surgical repair. Although intravenous digital subtraction angiography obviates the need for conventional angiography in many cases, movements from the patients, or superimposition of vascular structures can substantially degrade the quality of the images. Digital subtraction angiography with intra-arterial injection of contrast medium will be contemplated in patients with poor intravenous digital subtraction angiography studies prior to surgery.

  2. Digital subtraction angiography in ischemic cerebrovascular accidents

    International Nuclear Information System (INIS)

    Manelfe, C.; Bonafe, A.; Ducos de Lahitte, M.; Rascol, A.; Prere, J.; Guiraud, B.; Marc-Vergnes, J.P.

    1983-01-01

    Recent advances in computer and radiological technology have permitted reassessment of intravenous angiography in the evaluation of cerebrovascular disorders. Although digital subtraction angiography is a relatively new technique, it has rapidly gained a widespread acceptance. It has extended the use of angiography to outpatients and to people in whom conventional angiography is contraindicated. This reliable, safe, and relatively noninvasive technique offers the user two benefits: real-time subtraction and enhanced image quality. The system allows angiographic evaluation of the extracranial and intracranial vessels by means of intravenous injection of contrast material. Extracranial studies clearly demonstrate stenoses and occlusions of the major cervicocephalic arteries. Intracranial studies usually detect major cerebrovascular occlusions and provide insight into the collateral flow patterns. Intravenous digital subtraction angiography permits accurate assessment of cervicocephalic vessels after surgical repair. Although intravenous digital subtraction angiography obviates the need for conventional angiography in many cases, movements from the patients, or superimposition of vascular structures can substantially degrade the quality of the images. Digital subtraction angiography with intra-arterial injection of contrast medium will be contemplated in patients with poor intravenous digital subtraction angiography studies prior to surgery [fr

  3. Optimized respiratory-resolved motion-compensated 3D Cartesian coronary MR angiography.

    Science.gov (United States)

    Correia, Teresa; Ginami, Giulia; Cruz, Gastão; Neji, Radhouene; Rashid, Imran; Botnar, René M; Prieto, Claudia

    2018-04-22

    To develop a robust and efficient reconstruction framework that provides high-quality motion-compensated respiratory-resolved images from free-breathing 3D whole-heart Cartesian coronary magnetic resonance angiography (CMRA) acquisitions. Recently, XD-GRASP (eXtra-Dimensional Golden-angle RAdial Sparse Parallel MRI) was proposed to achieve 100% scan efficiency and provide respiratory-resolved 3D radial CMRA images by exploiting sparsity in the respiratory dimension. Here, a reconstruction framework for Cartesian CMRA imaging is proposed, which provides respiratory-resolved motion-compensated images by incorporating 2D beat-to-beat translational motion information to increase sparsity in the respiratory dimension. The motion information is extracted from interleaved image navigators and is also used to compensate for 2D translational motion within each respiratory phase. The proposed Optimized Respiratory-resolved Cartesian Coronary MR Angiography (XD-ORCCA) method was tested on 10 healthy subjects and 2 patients with cardiovascular disease, and compared against XD-GRASP. The proposed XD-ORCCA provides high-quality respiratory-resolved images, allowing clear visualization of the right and left coronary arteries, even for irregular breathing patterns. Compared with XD-GRASP, the proposed method improves the visibility and sharpness of both coronaries. Significant differences (p respiratory phases with larger motion amplitudes and subjects with irregular breathing patterns. A robust respiratory-resolved motion-compensated framework for Cartesian CMRA has been proposed and tested in healthy subjects and patients. The proposed XD-ORCCA provides high-quality images for all respiratory phases, independently of the regularity of the breathing pattern. © 2018 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine.

  4. XMetDB

    DEFF Research Database (Denmark)

    Spjuth, Ola; Rydberg, Patrik; Willighagen, Egon L

    2016-01-01

    Xenobiotic metabolism is an active research topic but the limited amount of openly available high-quality biotransformation data constrains predictive modeling. Current database often default to commonly available information: which enzyme metabolizes a compound, but neither experimental conditions...... nor the atoms that undergo metabolization are captured. We present XMetDB, an open access database for drugs and other xenobiotics and their respective metabolites. The database contains chemical structures of xenobiotic biotransformations with substrate atoms annotated as reaction centra...... is also available. The database is open for data deposition, and a curation scheme is in place for quality control. An extensive guide on how to enter experimental data into is available from the XMetDB wiki. XMetDB formalizes how biotransformation data should be reported, and the openly available...

  5. Is fasting necessary for elective cerebral angiography?

    Science.gov (United States)

    Kwon, O-K; Oh, C W; Park, H; Bang, J S; Bae, H-J; Han, M K; Park, S-H; Han, M H; Kang, H-S; Park, S-K; Whang, G; Kim, B-C; Jin, S-C

    2011-05-01

    In order to prevent unexpected events such as aspiration pneumonia, cerebral angiography has been performed under fasting in most cases. We investigated prospectively the necessity of fasting before elective cerebral angiography. The study is an open-labeled clinical trial without random allocation. In total, 2554 patients who underwent elective cerebral angiography were evaluated on development of nausea, vomiting, and pulmonary aspiration during and after angiography. Potential risks and benefits associated with fasting were provided in written documents and through personal counseling to patients before the procedure. The patients chose their fasting or nonfasting option. No restriction in diet was given after angiography. The patients were observed for 24 hours. Nausea and vomiting during and within 1 hour after angiography was considered as a positive event associated with cerebral angiography. The overall incidence of nausea and vomiting during and within 1 hour after angiography was 1.05% (27/2554 patients). There was no patient with pulmonary aspiration. No statistical difference in nausea and vomiting development between the fasting and the diet groups was found. The incidence of nausea and vomiting associated with cerebral angiography is low and not affected by diet or fasting. Pulmonary aspiration had no difference between the diet and the fasting group. Our study suggests that fasting may not be necessary for patients who undergo elective cerebral angiography.

  6. Prevalence of fenestrated basilar artery with magnetic resonance angiography: a transversal study.

    Science.gov (United States)

    Arráez-Aybar, L A; Villar-Martin, A; Poyatos-Ruiperez, C; Rodriguez-Boto, G; Arrazola-Garcia, J

    2013-08-01

    Fenestration of the basilar artery (BA) is a rare anatomical variation in comparison to those of the other intracranial arteries constituting the cerebral arterial circle. The incidence is difficult to ascertain and data vary according to type of series and modalities of detection. Basilar artery fenestration (BAF) has been reported in association with arteriovenous malformations, vascular variants, other developmental anomalies and neurovascular conflicts as a consequence of relations between the arterial branches of the BA and the nerves and other structures in the posterior cranial fossa. However, the real clinical interest of BAF is due to the possible formation of an aneurysm at the junction of the fenestrated segment and less frequently to the thrombosis of the vessels. With the aim to establish the prevalence of BAF in our population, we made a transversal pilot study of the first 200 MR angiographies performed on patients attending for the first time to control their base pathology (vascular or not). We have described three patients with this condition (representing a prevalence of 1.5 % on MR angiography) to shed additional light on this anomaly, two cases located at 1/3 proximal end (type 1-BAF) and one case located at joint 1/3 medium-1/3 distal end, locating distal to the anterior inferior cerebellar artery (type 4-BAF). In neither case was any other lesion found (i.e. aneurysm, infarctions, ischemia or thromboembolism). The pertinent clinical anatomy and embryological basis for this variation are reviewed, and the possible clinical implications and associated findings are discussed.

  7. Indications for coronary angiography

    International Nuclear Information System (INIS)

    Kaltenbach, M.; Vallbracht, C.

    1985-01-01

    Today selective coronary angiography, introduced by Sones in 1957, is used as clinical routine for diagnosing morphological changes in the coronary arteries. Hitherto, more recent techniques such as digital subtraction angiography cannot provide comparable information. Strict criteria for its indication depending on possible therapeutic consequences, have to be applied, although the risk is low with a letality of 0.01 to 0.05 percent. Radionuclear investigations can be used as additional tool in selected cases. The careful indication for coronary angiography usually implies the possible need for coronary bypass graft surgery of balloon angioplasty. (orig./MG) [de

  8. Evaluation of the restenosis of coronary artery after percutaneous transluminal coronary angioplasty by three-dimensional coronary magnetic resonance angiography

    International Nuclear Information System (INIS)

    Arisaka, Hiraku

    2000-01-01

    Coronary magnetic resonance angiography (MRA) has been recently brought into clinical use, however, there has not been reports on the comparison with MRA and conventional contrast coronary angiography (CAG) in the detection of the localization and characteristics of coronary restenosis after percutaneous transluminal coronary angioplasty (PTCA). To assess the restenosis of coronary artery after PTCA, this study compared three-dimensional (3D) coronary MRA and CAG. One hundred three patients (76 males and 27 females, average age of 64.6±9.3 years old) were performed coronary MRA at 3-6 months after PTCA. The right coronary artery (RCA) group consist of 21 patients, the left anterior descending branch (LAD) 63 patients and the left circumflex branch (LCX) 19 patients. Coronary MRA was performed with the patients in supine position on a 1.5 T whole body scanner (MAGNETOM VISION, Siemens AG, Germany) using body array coil. The imaging technique used a 3-D gradient echo sequence with respiratory gating and fat suppression. The slice thickness was 2 mm, slab thickness 32 mm, a field of view of 300 mm and a matrix of 128 x 256. Other parameters were an echo time of 2.7 ms and a repetition time of 600 to 1100 msec. The measurement time of 1 imaging slab took 15 to 20 minutes depending on the patient's heart rate. The coronary arteries were reconstructed from the 3-D data set using a multiplanar reconstruction (MPR) technique. According to previous coronary MRA studies, a significant stenosis with a luminal reduction of ≥50% was assumed if a marked signal reduction or signal loss of a vessel segment was visible. In CAG, 57 of 103 patients showed restenosis. In coronary MRA, 37 of 103 patients demonstrated restenosis. The sensitivity, specificity, positive and negative predictive values were 64.9%, 100%, 100% and 69.6%, respectively. Predictive accuracy was 79.6%. Three-dimensional coronary MRA is useful in a noninvasive diagnostic method to evaluate the coronary

  9. Gadolinium-enhanced MR angiography of arterial occlusive disease in lower extremity : comparison with conventional digital subtraction angiography

    International Nuclear Information System (INIS)

    Shin, Sang June; Koh, Young Hwan; Cha, Joo Hee; Kim, Hyu Beom; Chung, Jin Wook; Park, Jae Hyung

    2000-01-01

    To compare the diagnostic value of gadolinium-enhanced MR angiography with that of conventional digital subtraction angiography for the evaluation of lower extremity arterial occlusive diseases. In 26 patients with symptomatic lower extremity arterial occlusive disease, both conventional digital subtraction angiography (DSA) and gadolinium-enhanced MR angiography (CE-MRA) were performed during the same week. MR angiography was performed using three-dimensional gradient-echo acquisition before, and two sequential acquisitions after, the administration of gadolinium (0.2 mmol/kg). In 23 patients, two separate, contiguous areas were scanned using additional doses. In three patients, only one field with a suspicious lesion was scanned. Three radiologists independently analyzed the CE-MRA and DSA findings of each vascular segment (20 segments per arterial tree) for the presence of obstructive lesions; the grade assigned was either mild or none (less than 50%), stenotic (50%-99%), or occlusion (100%). From among a total of 462 segments, DSA detected 99 which were significantly narrowed (stenosis, 33; occlusion, 66). Using MR angiography, 102 segments (stenosis 39; occlusion, 63) were identified, and 94 lesions (stenosis, 32; occlusion, 62) were graded correctly. Seven lesions were overestimated and four were underestimated. For the detection of hemodynamically significant stenosis or occlusions using MR angiography, sensitivity, specificity, and diagnostic accuracy were 95%, 98%, and 98% (G=3D0.995, P less than 0.001), respectively. To prove the absence of lesions, we repeated DSA in two patients with arterial spasm due to puncture. Three occluded segments seen on DSA, which revealed intact segments on MR angiography, suggested slow distal flow after reconstitution. For the evaluation of lower extremity arterial occlusive disease, the diagnostic value of gadolinium-enhanced MR angiography is comparable with that of digital subtraction angiography. The advantages of the

  10. MR angiography in pediatric neurological disorders

    International Nuclear Information System (INIS)

    Lee, B.C.P.; Park, T.S.; Kaufman, B.A.

    1995-01-01

    MR angiography using 3D and 2D time-of-flight techniques were used to evaluate pediatric neurological disorders. MRA (arteriography) and MRV (venography) were abnormal in 63 and 45 cases, respectively. Conventional cerebral angiography was performed in 30 cases. These techniques were compared with MRI and conventional angiography. In addition, the value of MR angiography for surgical planning was subjectively evaluated. Our results showed that intracranial vessels were invariably better shown on MR angiography than on MRI. MRA and MRV were most useful in evaluating vascular distortions related to congenital brain malformations and intracranial tumors. MRA was valuable in detecting arterial narrowing but overestimated the degree of stenosis compared with conventional angiography. MRV was the technique of choice for evaluation of dural sinus and cerebral venous thrombosis and compression. MRA played little to no role in preoperative planning of vascular malformations and aneurysms. It did not appear to be accurate in assessing tumor vascularity or lesions in small arteries and arteritis. (orig.)

  11. Multi-section CT angiography compared with digital subtraction angiography in diagnosing major arterial hemorrhage in inflammatory pancreatic disease

    International Nuclear Information System (INIS)

    Hyare, Harpreet; Desigan, Sharmini; Nicholl, Helen; Guiney, Michael J.; Brookes, Jocelyn A.; Lees, William R.

    2006-01-01

    Purpose: Major arterial hemorrhage is an uncommon but serious complication of pancreatitis with high morbidity and mortality. Digital subtraction angiography (DSA) has long been the gold standard for the detection of a visceral artery pseudoaneurysm or for the site of active bleeding in patients with pancreatitis. Multi-section CT angiography is a minimally invasive technique which can provide high-resolution and high-contrast images of the arterial lumen and wall, with a much lower risk of complication and morbidity compared to DSA. The aim of this study was to determine the accuracy of multi-section CT angiography for the diagnosis of arterial complications of inflammatory pancreatitic disease. Materials and methods: A retrospective analysis of all patients undergoing visceral angiography for major bleeding as a complication of pancreatitis between 1998 and 2004 was performed. Twenty-nine studies in 25 patients (20 males, 5 females) with a mean age of 50.9 years (range 11-67 years) were identified where multi-section CT angiography was performed in the 24 h preceding the digital subtraction angiogram. Results: Digital subtraction angiography detected a pseudoaneurysm or contrast extravasation in 19 studies and no bleeding was demonstrated in 9 studies. CT angiography correctly identified the site and type of bleeding in 18 of the 19 positive studies. CT angiography detected extravasation of contrast in one study that was not demonstrated on digital subtraction angiography. The sensitivity and specificity for multi-section CT angiography for the detection of major arterial bleeding on a background of pancreatitis were 0.947 and 0.900, respectively. Conclusion: Multi-section CT angiography is a sensitive and accurate technique for the detection of major arterial hemorrhage in inflammatory pancreatic disease and should be considered as the first investigation in the management of these patients

  12. Integration of Three-Dimensional Rotational Angiography in Radiosurgical Treatment Planning of Cerebral Arteriovenous Malformations

    International Nuclear Information System (INIS)

    Conti, Alfredo; Pontoriero, Antonio; Farago, Giuseppe; Midili, Federica; Siragusa, Carmelo; Granata, Francesca; Pitrone, Antonio; De Renzis, Costantino; Longo, Marcello; Tomasello, Francesco

    2011-01-01

    Purpose: Accuracy in delineating the target volume is a major issue for successful stereotactic radiosurgery for arteriovenous malformations. The aim of the present study was to describe a method to integrate three-dimensional (3D) rotational angiography ( (3DRA)) into CyberKnife treatment planning and to investigate its potential advantages compared with computed tomography angiography (CTA) and magnetic resonance angiography. Methods and Materials: A total of 20 patients with a diagnosis of cerebral arteriovenous malformation were included in the present study. All patients underwent multislice computed tomography and 3D-volumetric CTA, (3DRA), and 3D magnetic resonance angiography. The contouring of the target and critical volumes was done separately using CTA and thereafter directly using (3DRA). The composite, conjoint, and disjoint volumes were measured. Results: The use of CTA or (3DRA) resulted in significant differences in the target and critical volumes. The target volume averaged 3.49 ± 3.01 mL measured using CTA and 3.26 ± 2.93 mL measured using (3DRA), for a difference of 8% (p < .05). The conjoint and disjoint volume analysis showed an 88% volume overlap. The qualitative evaluation showed that the excess volume obtained using CTA was mostly tissue surrounding the nidus and venous structures. The mean contoured venous volume was 0.67 mL measured using CTA and 0.88 mL (range, 0.1-2.7) measured using (3DRA) (p < .05). Conclusions: (3DRA) is a volumetric angiographic study that can be integrated into computer-based treatment planning. Although whether (3DRA) provides superior accuracy has not yet been proved, its high spatial resolution is attractive and offers a superior 3D view. This allows a better 3D understanding of the target volume and distribution of the radiation doses within the volume. Additional technical efforts to improve the temporal resolution and the development of software tools aimed at improving the performance of 3D contouring are

  13. Magnetic resonance angiography signal intensity as a marker of hemodynamic impairment in intracranial arterial stenosis.

    Directory of Open Access Journals (Sweden)

    Xinyi Leng

    Full Text Available Intracranial arterial stenosis (ICAS is the predominant cause of ischemic stroke and transient ischemic attack in Asia. Change of signal intensities (SI across an ICAS on magnetic resonance angiography (MRA may reflect its hemodynamic severity.In-patients with a symptomatic single ICAS detected on 3D time-of-flight MRA were recruited from 2 hospitals. Baseline and 1-year follow-up data were collected. Signal intensity ratio (SIR [ =  (mean post-stenotic SI -mean background SI/(mean pre-stenotic SI - mean background SI] was evaluated on baseline MRA to represent change of SIs across an ICAS. Acute infarct volume was measured on baseline diffusion-weighted images (DWI. Relationships between SIR and baseline characteristics as well as 1y outcomes were evaluated.Thirty-six subjects (86.1% males, mean age 55.0 were recruited. Overall, mean SIR was 0.84±0.23. Mean SIRs were not significantly different between the 23 (63.9% anatomically severe stenoses and the 13 (36.1% anatomically moderate stenoses (0.80±0.23 versus 0.92±0.21, p = 0.126. SIR was significantly, linearly and negatively correlated to acute infarct volume on DWI (Spearman correlation coefficient -0.471, p = 0.011. Two patients (5.6% had recurrent ischemic strokes at 1y, not related to SIR values.Change of signal intensities across an ICAS on MRA may reflect its hemodynamic and functional severity. Future studies are warranted to further verify the relationships between this index and prognosis of patients with symptomatic ICAS.

  14. Waveguide Cavity Resonator as a Source of Optical Squeezing

    Science.gov (United States)

    Stefszky, M.; Ricken, R.; Eigner, C.; Quiring, V.; Herrmann, H.; Silberhorn, C.

    2017-04-01

    We present the generation of continuous-wave optical squeezing from a titanium-in-diffused lithium niobate waveguide resonator. We directly measure 2.9 ±0.1 dB of single-mode squeezing, which equates to a produced level of 4.9 ±0.1 dB after accounting for detection losses. This device showcases the current capabilities of this waveguide architecture and precipitates more complicated integrated continuous-wave quantum devices in the continuous-variable regime.

  15. Magnetic resonance venography of congenital vascular malformations of the extremities

    International Nuclear Information System (INIS)

    Laor, T.; Burrows, P.E.; Hoffer, F.A.

    1996-01-01

    Contrast angiography can demonstrate the vascular components of a vascular malformation, but can be technically challenging in small patients with complex venous anomalies. We reviewed the role of magnetic resonance venography (MRV) in the evaluation of children with predominantly low-flow, vascular malformations of the extremities. MRV (2D time-of-flight technique) and magnetic resonance (MR) imaging examinations were performed in ten young patients with congential predominantly low-flow vascular malformations of the extremities. MR imaging was used to characterize and determine the extent of the malformations, and MRV to evaluate the deep and superficial venous channels. In all patients, MRV studies were reviewed in conjunction with contrast angiograms, considered the gold standard, to confirm the findings. All signficant channel anomalies seen with contrast angiography were identified with MRV. In addition, MRV demonstrated some veins that were not intentionally opacified during contrast studies. MRV demonstrates both the superficial and deep conducting veins, whereas contrast angiography is a more directed study, evaluating only those channels intentionally opacified. Together, MR imaging and MRV data can non-invasively form the basis for determining the prognosis and choosing the individual treatment of congenital vascular malformations of the extremities. (orig.)

  16. Digital angiography in pulmonary embolism

    International Nuclear Information System (INIS)

    Bjoerk, L.

    1986-01-01

    Pulmonary digital subtraction angiography was diagnostic in 98.3% of patients with possible acute pulmonary embolism. The procedure was well tolerated even in severely ill patients. A large image intensifier made simultaneous imaging of both lungs possible reducing the number of contrast injections necessary. Small volumes of low iso-osmolar concentration of modern contrast media were used. There was no need for catherization of the pulmonary artery. Theoretical considerations and our limited experience indicate that this will reduce the number of complications compared with conventional pulmonary angiography. The procedure is rapidly performed and the diagnostic accuracy high. This makes digital subtraction angiography cost effective. Digital pulmonary angiography can be recommended as the primary diagnostic method in most patients with possible pulmonary embolism. (orig.)

  17. Infrared-laser-based fundus angiography

    Science.gov (United States)

    Klingbeil, Ulrich; Canter, Joseph M.; Lesiecki, Michael L.; Reichel, Elias

    1994-06-01

    Infrared fundus angiography, using the fluorescent dye indocyanine green (ICG), has shown great potential in delineating choroidal neovascularization (CNV) otherwise not detectable. A digital retinal imaging system containing a diode laser for illumination has been developed and optimized to perform high sensitivity ICG angiography. The system requires less power and generates less pseudo-fluorescence background than nonlaser devices. During clinical evaluation at three retinal centers more than 200 patients, the majority of which had age-related macular degeneration, were analyzed. Laser based ICG angiography was successful in outlining many of the ill-defined or obscure CNV as defined by fluorescein angiography. The procedure was not as successful with classic CNV. ICG angiograms were used to prepare and guide laser treatment.

  18. Inhibiting the NLRP3 Inflammasome Activation with MCC950 Ameliorates Diabetic Encephalopathy in db/db Mice

    Directory of Open Access Journals (Sweden)

    Yadong Zhai

    2018-02-01

    Full Text Available Diabetes is associated with a high risk of developing cognitive dysfunction and neuropsychiatric disabilities, and these disease symptomsare termed diabetic encephalopathy (DEP. Inflammation is involved in the development of DEP. The cleavage and maturation of the proinflammatory cytokine interleukin (IL-1β is regulated by the NLRP3 inflammasome. Obese and type 2 diabetic db/db mice show anxiety- and depression-like behaviors and cognitive disorders associated with hippocampal inflammation. The purpose of this study was to explore the role of NLRP3 inflammasome in DEP. Results showed that expression levels of inflammasome components including NLRP3, apoptosis-associated speck-like protein (ASC, and caspase-1, as well as IL-1β in the hippocampus of diabetic db/db mice were higher than those of non-diabetic db/m mice. Treatment of db/db mice with NLRP3 inflammasome inhibitor MCC950 ameliorated anxiety- and depression-like behaviors as well as cognitive dysfunction, and reversed increased NLRP3, ASC, and IL-1βexpression levels and caspase-1 activity in hippocampus. Moreover, MCC950 treatment significantly improved insulin sensitivity in db/db mice. These results demonstrate that inhibition of NLRP3 inflammasome activation may prove to be a potential therapeutic approach for DEP treatment.

  19. Resistin production from adipose tissue is decreased in db/db obese mice, and is reversed by rosiglitazone.

    Directory of Open Access Journals (Sweden)

    Hongying Ye

    Full Text Available OBJECTIVE: This study was designed to (1 investigate the expression profiles of resistin in db/db mice and its dynamic association with metabolic parameters; and (2 evaluate the effects of Rosiglitazone on production of resistin. METHODS: Db/db mice and their lean litter mates were used for this study. Epididymal fat tissue was excised from mice of different age (from 5 to 12 weeks for ex vivo incubation. Resistin,along with adiponectin,in serum and conditioned culture medium of epididymal fat pads were measured with immunoassays. The gene expression of resistin was determined by real-time PCR. Rosiglitazone or the vehicle (PBS was administered into db/db mice by daily intra-gastric gavage. Differentiated 3T3-L1 adipocytes were used for in vitro evaluation. RESULTS: The secretion of resistin from the fat pads in db/db mice was significantly lower than that in lean mice (P<0.01. The mRNA expression of the resistin gene in fat tissue of db/db mice at the age of 5 weeks was decreased by 60.5% compared to lean controls (p<0.05. Serum levels of resistin were comparable between the obese and lean groups, perhaps due to the increased total fat mass in db/db mice. Correlation analysis showed that serum resistin levels were positively correlated to resistin secretion from fat pads(r = 0.844,P = 0.000, while negatively associated with the body weight (r = -0.515, P = 0.000 and fasting glucose level (r = -0.357, P = 0.002. Notably, treatment with rosiglitazone increased the serum resistin levels by 66.4%(P<0.05in db/db mice. In 3T3-L1 adipocytes, Rosiglitazone (10 uM markedly enhanced the secretion of resistin by 120% (P<0.01 and its gene expression by 78.1% (P<0.05. CONCLUSION: Both resistin gene expression and its secretion from the epididymal adipose tissue were decreased in db/db obese mice, while the insulin-sensitizing drug rosiglitazone increased resistin production. Our results do not support the role of resistin as an

  20. Patient satisfaction with coronary CT angiography, myocardial CT perfusion, myocardial perfusion MRI, SPECT myocardial perfusion imaging and conventional coronary angiography

    Energy Technology Data Exchange (ETDEWEB)

    Feger, S.; Rief, M.; Zimmermann, E.; Richter, F.; Roehle, R. [Freie Universitaet Berlin, Department of Radiology, Charite - Universitaetsmedizin Berlin Campus Mitte, Humboldt-Universitaet zu Berlin, Berlin (Germany); Dewey, M. [Freie Universitaet Berlin, Department of Radiology, Charite - Universitaetsmedizin Berlin Campus Mitte, Humboldt-Universitaet zu Berlin, Berlin (Germany); Institut fuer Radiologie, Berlin (Germany); Schoenenberger, E. [Medizinische Hochschule Hannover, Department of Medicine, Hannover (Germany)

    2015-07-15

    To evaluate patient acceptance of noninvasive imaging tests for detection of coronary artery disease (CAD), including single-photon emission computed tomography myocardial perfusion imaging (SPECT-MPI), stress perfusion magnetic resonance imaging (MRI), coronary CT angiography (CTA) in combination with CT myocardial stress perfusion (CTP), and conventional coronary angiography (CCA). Intraindividual comparison of perception of 48 patients from the CORE320 multicentre multinational study who underwent rest and stress SPECT-MPI with a technetium-based tracer, combined CTA and CTP (both with contrast agent, CTP with adenosine), MRI, and CCA. The analysis was performed by using a validated questionnaire. Patients had significantly more concern prior to CCA than before CTA/CTP (p < 0.001). CTA/CTP was also rated as more comfortable than SPECT-MPI (p = 0.001). Overall satisfaction with CT was superior to that of MRI (p = 0.007). More patients preferred CT (46 %; p < 0.001) as a future diagnostic test. Regarding combined CTA/CTP, CTP was characterised by higher pain levels and an increased frequency of angina pectoris during the examination (p < 0.001). Subgroup analysis showed a higher degree of pain during SPECT-MPI with adenosine stress compared to physical exercise (p = 0.016). All noninvasive cardiac imaging tests are well accepted by patients, with CT being the preferred examination. (orig.)

  1. Scaling MongoDB

    CERN Document Server

    Chodorow, Kristina

    2011-01-01

    Create a MongoDB cluster that will to grow to meet the needs of your application. With this short and concise book, you'll get guidelines for setting up and using clusters to store a large volume of data, and learn how to access the data efficiently. In the process, you'll understand how to make your application work with a distributed database system. Scaling MongoDB will help you: Set up a MongoDB cluster through shardingWork with a cluster to query and update dataOperate, monitor, and backup your clusterPlan your application to deal with outages By following the advice in this book, you'l

  2. RavenDB high performance

    CERN Document Server

    Ritchie, Brian

    2013-01-01

    RavenDB High Performance is comprehensive yet concise tutorial that developers can use to.This book is for developers & software architects who are designing systems in order to achieve high performance right from the start. A basic understanding of RavenDB is recommended, but not required. While the book focuses on advanced topics, it does not assume that the reader has a great deal of prior knowledge of working with RavenDB.

  3. Normal variants of the intracranial circulation demonstrated by MR angiography at 3 T

    International Nuclear Information System (INIS)

    Parmar, H.; Sitoh, Y.Y.; Hui, F.

    2005-01-01

    Magnetic resonance angiography (MRA) at 3 T offers increased signal to noise ratio with better background suppression, leading to exquisite depiction of the intracranial circulation. We present a pictorial review of the normal variations and anomalies of the intracranial circulation detected on MRA performed on a high field 3 T clinical scanner using parallel imaging techniques. The salient imaging features of these anomalies and normal variations are discussed with relevance to clinical practice

  4. High-q microring resonator with narrow free spectral range for pulse repetition rate multiplication

    DEFF Research Database (Denmark)

    Pu, Minhao; Ji, Hua; Frandsen, Lars Hagedorn

    2009-01-01

    We demonstrate a silicon-on-insulator microring resonator with a free-spectral-range of 0.32 nm, an extinction ratio of 27 dB, and a quality factor of ~140900 at 1550 nm that is used for pulse repetition-rate multiplication from 10 to 40 GHz.......We demonstrate a silicon-on-insulator microring resonator with a free-spectral-range of 0.32 nm, an extinction ratio of 27 dB, and a quality factor of ~140900 at 1550 nm that is used for pulse repetition-rate multiplication from 10 to 40 GHz....

  5. Angiography and the gastrointestinal bleeder

    International Nuclear Information System (INIS)

    Baum, S.

    1982-01-01

    The role of angiography in the diagnosis and treatment of gastrointestinal hemorrhage is discussed. Three categories of gastrointestinal bleeding are considered: upper gastrointestinal bleeding due to gastroesophageal varices, upper gastrointestinal bleeding of arterial or capillary origin, and lower gastrointestinal bleeding. The advantages and disadvantages of angiography are compared with those of radionuclide scanning and endoscopy or colonoscopy. It is anticipated that, as radionuclide scans are more widely employed, angiography will eventually be performed only in those patients with positive scans

  6. Improvement of chemical shift selective saturation (CHESS) pulse for MR angiography

    International Nuclear Information System (INIS)

    Ishimori, Yoshiyuki; Sashie, Hiroyuki; Hiraga, Akira; Matsuda, Tsuyoshi

    2000-01-01

    We improved the fat suppression technique based on chemical shift selective saturation (CHESS). To do this, we shortened the duration of the CHESS pulse to achieve a short repetition time (TR) for MR angiography (MRA). A short-duration CHESS pulse causes broad frequency band saturation, creating extensive offset from the resonance frequency of water. In our phantom experiment, the best parameters of the short-duration CHESS pulse were 3.84 ms in duration, -650 Hz in offset frequency from water resonance, and had a 130-degree flip angle. With this technique, MRA will be able to be carried out without a significant increase in TR. Thus, better vessel contrast will be maintained in time-of-flight (TOF) MRA or contrast-enhanced MRA when using the maximum intensity projection (MIP) method. (author)

  7. Cost effectiveness of coronary angiography and calcium scoring using CT and stress MRI for diagnosis of coronary artery disease

    International Nuclear Information System (INIS)

    Dewey, Marc; Hamm, Bernd

    2007-01-01

    We compared the cost effectiveness of recent approaches [coronary angiography and calcium scoring using computed tomography (CT) and stress magnetic resonance imaging (MRI)] to the diagnosis of coronary artery disease (CAD) with those of the traditional diagnostic modalities [conventional angiography (CATH), exercise ECG, and stress echocardiography] using a decision tree model. For patients with a 10% to 50% pretest likelihood of coronary artery disease, non-invasive coronary angiography using CT was the most cost effective approach, with costs per correctly identified CAD patient of EUR4,435 (10% likelihood) to EUR1,469 (50% likelihood). Only for a pretest likelihood of 30% to 40% was calcium scoring using CT more cost effective than any of the traditional diagnostic modalities, while MRI was not cost effective for any pretest likelihood. At a pretest likelihood of 60%, CT coronary angiography and CATH were equally effective, while CATH was most cost effective for a pretest likelihood of at least 70%. In conclusion, up to a pretest likelihood for coronary artery disease of 50%, CT coronary angiography is the most cost-effective procedure, being superior to the other new modalities and the most commonly used traditional diagnostic modalities. With a very high likelihood for disease (above 60%), CATH is the most effective procedure from the perspective of society. (orig.)

  8. ProteomicsDB.

    Science.gov (United States)

    Schmidt, Tobias; Samaras, Patroklos; Frejno, Martin; Gessulat, Siegfried; Barnert, Maximilian; Kienegger, Harald; Krcmar, Helmut; Schlegl, Judith; Ehrlich, Hans-Christian; Aiche, Stephan; Kuster, Bernhard; Wilhelm, Mathias

    2018-01-04

    ProteomicsDB (https://www.ProteomicsDB.org) is a protein-centric in-memory database for the exploration of large collections of quantitative mass spectrometry-based proteomics data. ProteomicsDB was first released in 2014 to enable the interactive exploration of the first draft of the human proteome. To date, it contains quantitative data from 78 projects totalling over 19k LC-MS/MS experiments. A standardized analysis pipeline enables comparisons between multiple datasets to facilitate the exploration of protein expression across hundreds of tissues, body fluids and cell lines. We recently extended the data model to enable the storage and integrated visualization of other quantitative omics data. This includes transcriptomics data from e.g. NCBI GEO, protein-protein interaction information from STRING, functional annotations from KEGG, drug-sensitivity/selectivity data from several public sources and reference mass spectra from the ProteomeTools project. The extended functionality transforms ProteomicsDB into a multi-purpose resource connecting quantification and meta-data for each protein. The rich user interface helps researchers to navigate all data sources in either a protein-centric or multi-protein-centric manner. Several options are available to download data manually, while our application programming interface enables accessing quantitative data systematically. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

  9. Impairment of the vascular relaxation and differential expression of caveolin-1 of the aorta of diabetic +db/+db mice.

    Science.gov (United States)

    Lam, Tze Yan; Seto, Sai Wang; Lau, Yee Man; Au, Lai Shan; Kwan, Yiu Wa; Ngai, Sai Ming; Tsui, Kwong Wing

    2006-09-28

    In this study, we compared the endothelium-dependent and -independent relaxation of the isolated thoracic aorta of control (+db/+m) and diabetic (+db/+db) (C57BL/KsJ) mice. The gene expression (mRNA and protein) level of the muscarinic M(3) receptors, endothelial nitric oxide synthase (eNOS) and caveolin-1 of the aorta was also evaluated. Acetylcholine caused a concentration-dependent, N(G)-nitro-L-arginine methyl-ester (20 microM)-sensitive relaxation, with approximately 100% relaxation at 10 microM, in +db/+m mice. In +db/+db mice, the acetylcholine-induced relaxation was significantly smaller (maximum relaxation: approximately 80%). The sodium nitroprusside-mediated relaxation was slightly diminished in +db/+db mice, compared to +db/+m mice. However, there was no significant difference in the isoprenaline- and cromakalim-induced relaxation observed in both species. The mRNA and protein expression levels of caveolin-1 were significantly higher in the aorta of +db/+db mice. In contrast, there was no difference in the mRNA and protein expression levels of eNOS and muscarinic M(3) receptors between these mice. Our results demonstrate that the impairment of the acetylcholine-induced, endothelium-dependent aortic relaxation observed in +db/+db mice was probably associated with an enhanced expression of caveolin-1 mRNA and protein.

  10. Restructuring of the Gut Microbiome by Intermittent Fasting Prevents Retinopathy and Prolongs Survival in db/db Mice.

    Science.gov (United States)

    Beli, Eleni; Yan, Yuanqing; Moldovan, Leni; Vieira, Cristiano P; Gao, Ruli; Duan, Yaqian; Prasad, Ram; Bhatwadekar, Ashay; White, Fletcher A; Townsend, Steven; Chan, Luisa; Ryan, Caitlin N; Morton, Daniel; Moldovan, Emil G; Chu, Fang-I; Oudit, Gavin Y; Derendorf, Hartmut; Adorini, Luciano; Wang, Xiaoxin X; Evans-Molina, Carmella; Mirmira, Raghavendra G; Boulton, Michael E; Yoder, Mervin C; Li, Qiuhong; Levi, Moshe; Busik, Julia V; Grant, Maria B

    2018-04-30

    Intermittent fasting (IF) protects against the development of metabolic diseases and cancer, but whether it can prevent diabetic microvascular complications is not known. In db/db mice, we examined the impact of long-term IF on diabetic retinopathy (DR). Despite no change in glycated hemoglobin, db/db mice on the IF regimen displayed significantly longer survival and a reduction in DR endpoints, including acellular capillaries and leukocyte infiltration. We hypothesized that IF mediated changes in the gut microbiota would produce beneficial metabolites and prevent the development of DR. Microbiome analysis revealed increased levels of Firmicutes and decreased Bacteroidetes and Verrucomicrobia Compared to db/db mice on ad-libitum (AL) feeding, changes in the microbiome of the db/db mice on IF were associated with increases in gut mucin, goblet cell number and villi length and reductions in plasma peptidoglycan. Consistent with the known modulatory effects of Firmicutes on bile acid (BA) metabolism, measurement of BAs demonstrated a significant increase of tauroursodeoxycholate (TUDCA), a neuroprotective BA, in db/db on IF but not in db/db on AL feeding. TGR-5, the TUDCA receptor, was found in neural cells of the retina primary ganglion cells. Expression of TGR5 did not change with IF or diabetes. However, IF reduced retinal TNF-α mRNA, which is a key downstream target of TGR-5 activation. Pharmacological activation of TGR5 using INT-767 prevented DR in a second diabetic mouse model. These findings support the concept that IF prevents DR by restructuring the microbiota towards species producing TUDCA and subsequent retinal protection by TGR5 activation. © 2018 by the American Diabetes Association.

  11. MR angiography of the body. Technique and clinical applications

    Energy Technology Data Exchange (ETDEWEB)

    Neri, Emanuele [Pisa Univ. Radiodiagnostica 1 Universitaria (Italy). Diagnostic and Interventional Radiology Dept. of Oncology, Transplants, and Advanced Technologies in Medicine; Cosottini, Mirco [Pisa Univ. (Italy). Unit of Neuroradiology Dept. of Neurosciences; Caramella, Davide (eds.) [Pisa Univ. (Italy). Diagnostic and Interventional Radiology Dept. of Oncology, Transplants, and Advanced Technologies in Medicine

    2010-07-01

    Magnetic resonance angiography (MRA) continues to undergo exciting technological advances that are rapidly being translated into clinical practice. It also has evident advantages over other imaging modalities, including better patient safety compared with CT angiography and superior accuracy and contrast resolution compared with ultrasonography. With the aid of numerous high-quality illustrations, this book reviews the current role of MRA of the body. It is divided into three sections. The first section is devoted to issues relating to image acquisition technique and sequences. Individual chapters focus on flow-based MRA, contrast media, contrast-enhanced MRA, artifacts, and image processing. The second and principal section of the book addresses the clinical applications of MRA in various parts of the body, including the neck vessels, the spine, the thoracic aorta and pulmonary vessels, the heart and coronary arteries, the abdominal aorta and renal arteries, and peripheral vessels. The role of the blood pool contrast agents for the diagnosis and characterization of vascular disease is fully explored. The final section considers the role of MRA in patients undergoing liver or pancreas and kidney transplantation. This book will be an invaluable aid to all radiologists who work with MRA. (orig.)

  12. Analysis and design of a coupled coaxial line TEM resonator for magnetic resonance imaging

    International Nuclear Information System (INIS)

    Benahmed, Nasreddine; Feham, Mohammed; Khelif, M'Hamed

    2006-01-01

    In this paper, we have successfully realized a numerical tool to analyse and to design an n-element unloaded coaxial line transverse electromagnetic (TEM) resonator. This numerical tool allows the determination of the primary parameters, matrices [L], [C] and [R], and simulates the frequency response of S 11 at the RF port of the designed TEM resonator. The frequency response permits evaluation of the unloaded quality factor Q 0 . As an application, we present the analysis and the design of an eight-element unloaded TEM resonator for animal studies at 4.7 T. The simulated performance has a -62.81 dB minimum reflection and a quality factor of 260 around 200 MHz

  13. DBA2J db/db mice are susceptible to early albuminuria and glomerulosclerosis that correlate with systemic insulin resistance.

    Science.gov (United States)

    Østergaard, Mette V; Pinto, Vanda; Stevenson, Kirsty; Worm, Jesper; Fink, Lisbeth N; Coward, Richard J M

    2017-02-01

    Diabetic nephropathy (DN) is the leading cause of kidney failure in the world. To understand important mechanisms underlying this condition, and to develop new therapies, good animal models are required. In mouse models of type 1 diabetes, the DBA/2J strain has been shown to be more susceptible to develop kidney disease than other common strains. We hypothesized this would also be the case in type 2 diabetes. We studied db/db and wild-type (wt) DBA/2J mice and compared these with the db/db BLKS/J mouse, which is currently the most widely used type 2 DN model. Mice were analyzed from age 6 to 12 wk for systemic insulin resistance, albuminuria, and glomerular histopathological and ultrastructural changes. Body weight and nonfasted blood glucose were increased by 8 wk in both genders, while systemic insulin resistance commenced by 6 wk in female and 8 wk in male db/db DBA/2J mice. The urinary albumin-to-creatinine ratio (ACR) was closely linked to systemic insulin resistance in both sexes and was increased ~50-fold by 12 wk of age in the db/db DBA/2J cohort. Glomerulosclerosis, foot process effacement, and glomerular basement membrane thickening were observed at 12 wk of age in db/db DBA/2J mice. Compared with db/db BLKS/J mice, db/db DBA/2J mice had significantly increased levels of urinary ACR, but similar glomerular histopathological and ultrastructural changes. The db/db DBA/2J mouse is a robust model of early-stage albuminuric DN, and its levels of albuminuria correlate closely with systemic insulin resistance. This mouse model will be helpful in defining early mechanisms of DN and ultimately the development of novel therapies. Copyright © 2017 the American Physiological Society.

  14. Contrast-enhanced magnetic resonance angiography for the detection of crossing renal vessels in children with symptomatic ureteropelvic junction obstruction: comparison with operative findings.

    Science.gov (United States)

    Calder, Alistair D; Hiorns, Melanie P; Abhyankar, Aruna; Mushtaq, Imran; Olsen, Oystein E

    2007-04-01

    Crossing renal vessels (CRV) are associated with ureteropelvic junction (UPJ) obstruction, particularly when presentation is beyond the neonatal period. Their presence may influence surgical management. To evaluate the accuracy of contrast-enhanced magnetic resonance angiography (CE-MRA) in the identification of CRV in children requiring surgical treatment of symptomatic UPJ obstruction, against a gold standard of laparoscopic or open surgical findings. We reviewed CE-MRA studies (3-D T2-weighted turbo spin-echo and multiphase 3-D spoiled gradient echo following intravenous gadolinium administration) of 14 children, age range 6-15 years, performed prior to surgery for suspected CRV-related UPJ obstruction. Consensus reviews of the CE-MRA studies were compared with surgical findings. CE-MRA demonstrated CRV at the level of the obstruction in nine and no crossing vessels in five children. These were all verified intraoperatively (chi2=14.0; Pchildren older than 6 years with symptomatic UPJ obstruction.

  15. Bile acid sequestration reduces plasma glucose levels in db/db mice by increasing its metabolic clearance rate.

    Directory of Open Access Journals (Sweden)

    Maxi Meissner

    Full Text Available AIMS/HYPOTHESIS: Bile acid sequestrants (BAS reduce plasma glucose levels in type II diabetics and in murine models of diabetes but the mechanism herein is unknown. We hypothesized that sequestrant-induced changes in hepatic glucose metabolism would underlie reduced plasma glucose levels. Therefore, in vivo glucose metabolism was assessed in db/db mice on and off BAS using tracer methodology. METHODS: Lean and diabetic db/db mice were treated with 2% (wt/wt in diet Colesevelam HCl (BAS for 2 weeks. Parameters of in vivo glucose metabolism were assessed by infusing [U-(13C]-glucose, [2-(13C]-glycerol, [1-(2H]-galactose and paracetamol for 6 hours, followed by mass isotopologue distribution analysis, and related to metabolic parameters as well as gene expression patterns. RESULTS: Compared to lean mice, db/db mice displayed an almost 3-fold lower metabolic clearance rate of glucose (p = 0.0001, a ∼300% increased glucokinase flux (p = 0.001 and a ∼200% increased total hepatic glucose production rate (p = 0.0002. BAS treatment increased glucose metabolic clearance rate by ∼37% but had no effects on glucokinase flux nor total hepatic or endogenous glucose production. Strikingly, BAS-treated db/db mice displayed reduced long-chain acylcarnitine content in skeletal muscle (p = 0.0317 but not in liver (p = 0.189. Unexpectedly, BAS treatment increased hepatic FGF21 mRNA expression 2-fold in lean mice (p = 0.030 and 3-fold in db/db mice (p = 0.002. CONCLUSIONS/INTERPRETATION: BAS induced plasma glucose lowering in db/db mice by increasing metabolic clearance rate of glucose in peripheral tissues, which coincided with decreased skeletal muscle long-chain acylcarnitine content.

  16. Curcumin restores mitochondrial functions and decreases lipid peroxidation in liver and kidneys of diabetic db/db mice

    Directory of Open Access Journals (Sweden)

    María G Soto-Urquieta

    2014-01-01

    Full Text Available BACKGROUND: Nitrosative and oxidative stress play a key role in obesity and diabetes-related mitochondrial dysfunction. The objective was to investigate the effect of curcumin treatment on state 3 and 4 oxygen consumption, nitric oxide (NO synthesis, ATPase activity and lipid oxidation in mitochondria isolated from liver and kidneys of diabetic db/db mice. RESULTS: Hyperglycaemia increased oxygen consumption and decreased NO synthesis in liver mitochondria isolated from diabetic mice relative to the control mice. In kidney mitochondria, hyperglycaemia increased state 3 oxygen consumption and thiobarbituric acid-reactive substances (TBARS levels in diabetic mice relative to control mice. Interestingly, treating db/db mice with curcumin improved or restored these parameters to normal levels; also curcumin increased liver mitochondrial ATPase activity in db/db mice relative to untreated db/db mice. CONCLUSIONS: These findings suggest that hyperglycaemia modifies oxygen consumption rate, NO synthesis and increases TBARS levels in mitochondria from the liver and kidneys of diabetic mice, whereas curcumin may have a protective role against these alterations.

  17. Diabetic db/db mice do not develop heart failure upon pressure overload: a longitudinal in vivo PET, MRI, and MRS study on cardiac metabolic, structural, and functional adaptations.

    Science.gov (United States)

    Abdurrachim, Desiree; Nabben, Miranda; Hoerr, Verena; Kuhlmann, Michael T; Bovenkamp, Philipp; Ciapaite, Jolita; Geraets, Ilvy M E; Coumans, Will; Luiken, Joost J F P; Glatz, Jan F C; Schäfers, Michael; Nicolay, Klaas; Faber, Cornelius; Hermann, Sven; Prompers, Jeanine J

    2017-08-01

    Heart failure is associated with altered myocardial substrate metabolism and impaired cardiac energetics. Comorbidities like diabetes may influence the metabolic adaptations during heart failure development. We quantified to what extent changes in substrate preference, lipid accumulation, and energy status predict the longitudinal development of hypertrophy and failure in the non-diabetic and the diabetic heart. Transverse aortic constriction (TAC) was performed in non-diabetic (db/+) and diabetic (db/db) mice to induce pressure overload. Magnetic resonance imaging, 31P magnetic resonance spectroscopy (MRS), 1H MRS, and 18F-fluorodeoxyglucose-positron emission tomography (PET) were applied to measure cardiac function, energy status, lipid content, and glucose uptake, respectively. In vivo measurements were complemented with ex vivo techniques of high-resolution respirometry, proteomics, and western blotting to elucidate the underlying molecular pathways. In non-diabetic mice, TAC induced progressive cardiac hypertrophy and dysfunction, which correlated with increased protein kinase D-1 (PKD1) phosphorylation and increased glucose uptake. These changes in glucose utilization preceded a reduction in cardiac energy status. At baseline, compared with non-diabetic mice, diabetic mice showed normal cardiac function, higher lipid content and mitochondrial capacity for fatty acid oxidation, and lower PKD1 phosphorylation, glucose uptake, and energetics. Interestingly, TAC affected cardiac function only mildly in diabetic mice, which was accompanied by normalization of phosphorylated PKD1, glucose uptake, and cardiac energy status. The cardiac metabolic adaptations in diabetic mice seem to prevent the heart from failing upon pressure overload, suggesting that restoring the balance between glucose and fatty acid utilization is beneficial for cardiac function. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2017. For permissions

  18. Resistin production from adipose tissue is decreased in db/db obese mice, and is reversed by rosiglitazone.

    Science.gov (United States)

    Ye, Hongying; Zhang, Herbert J; Xu, Aimin; Hoo, Ruby L C

    2013-01-01

    This study was designed to (1) investigate the expression profiles of resistin in db/db mice and its dynamic association with metabolic parameters; and (2) evaluate the effects of Rosiglitazone on production of resistin. Db/db mice and their lean litter mates were used for this study. Epididymal fat tissue was excised from mice of different age (from 5 to 12 weeks) for ex vivo incubation. Resistin,along with adiponectin,in serum and conditioned culture medium of epididymal fat pads were measured with immunoassays. The gene expression of resistin was determined by real-time PCR. Rosiglitazone or the vehicle (PBS) was administered into db/db mice by daily intra-gastric gavage. Differentiated 3T3-L1 adipocytes were used for in vitro evaluation. The secretion of resistin from the fat pads in db/db mice was significantly lower than that in lean mice (Plean controls (plean groups, perhaps due to the increased total fat mass in db/db mice. Correlation analysis showed that serum resistin levels were positively correlated to resistin secretion from fat pads(r = 0.844,P = 0.000), while negatively associated with the body weight (r = -0.515, P = 0.000) and fasting glucose level (r = -0.357, P = 0.002). Notably, treatment with rosiglitazone increased the serum resistin levels by 66.4%(Pproduction. Our results do not support the role of resistin as an etiological link between obesity and diabetes.

  19. Sequential gadolinium-enhanced magnetic resonance angiography of the aortoiliac and the femoropopliteal arteries with repetitive administration of low-dose contrast agent

    International Nuclear Information System (INIS)

    Ito, Koichiro; Kumazaki, Tatsuo

    2000-01-01

    To obtain a wide-range contrast MR angiography in a single examination, we performed two sequential administrations of low-dose (0.08 mmol/kg) gadolinium diethylenetriaminepentaacetic acid (Gd-DTPA) with three dimensional inversion recovery prepared fast spoiled gradient recalled acquisition in the steady-state (3D IR-fast SPGR) sequence. Signal characteristics of the sequence were estimated by computed simulations and an in vitro study. A clinical study of 19 examinations was done with sequential MR angiography of the aortoiliac and femoropopliteal arteries. Great signal differences were observed between the high and low Gd concentrations. Higher Gd concentrations generated significantly stronger signals. Greater signals were produced at TIs of longer than 150 msec than at shorter than 100 msec. In the clinical study, the arteries were visualized with sufficient signals even with a small amount of contrast agent. Contrast-to-noise ratios between the arteries and surrounding skeletal muscles or fat tissues ranged from 10.5±9.6 to 4.7±2.2 and 6.6±2.8 to -3.1±11.2, respectively. No venous enhancement was found with diluted contrast agent on the second MR angiography. Two consecutive contrast MR angiographies can be obtained with repetitive administration of low-dose contrast agent. (author)

  20. Sequential gadolinium-enhanced magnetic resonance angiography of the aortoiliac and the femoropopliteal arteries with repetitive administration of low-dose contrast agent

    Energy Technology Data Exchange (ETDEWEB)

    Ito, Koichiro [Nippon Medical School, Inba, Chiba (Japan). Chiba Hokusoh Hospital; Kumazaki, Tatsuo

    2000-12-01

    To obtain a wide-range contrast MR angiography in a single examination, we performed two sequential administrations of low-dose (0.08 mmol/kg) gadolinium diethylenetriaminepentaacetic acid (Gd-DTPA) with three dimensional inversion recovery prepared fast spoiled gradient recalled acquisition in the steady-state (3D IR-fast SPGR) sequence. Signal characteristics of the sequence were estimated by computed simulations and an in vitro study. A clinical study of 19 examinations was done with sequential MR angiography of the aortoiliac and femoropopliteal arteries. Great signal differences were observed between the high and low Gd concentrations. Higher Gd concentrations generated significantly stronger signals. Greater signals were produced at TIs of longer than 150 msec than at shorter than 100 msec. In the clinical study, the arteries were visualized with sufficient signals even with a small amount of contrast agent. Contrast-to-noise ratios between the arteries and surrounding skeletal muscles or fat tissues ranged from 10.5{+-}9.6 to 4.7{+-}2.2 and 6.6{+-}2.8 to -3.1{+-}11.2, respectively. No venous enhancement was found with diluted contrast agent on the second MR angiography. Two consecutive contrast MR angiographies can be obtained with repetitive administration of low-dose contrast agent. (author)

  1. CouchDB the definitive guide

    CERN Document Server

    Anderson, J; Slater, Noah

    2010-01-01

    Three of CouchDB's creators show you how to use this document-oriented database as a standalone application framework or with high-volume, distributed applications. With its simple model for storing, processing, and accessing data, CouchDB is ideal for web applications that handle huge amounts of loosely structured data. That alone would stretch the limits of a relational database, yet CouchDB offers an open source solution that's reliable, scales easily, and responds quickly. CouchDB works with self-contained data that has loose or ad-hoc connections. It's a model that fits many real-world

  2. MDCT angiography and transcatheter embolization in management ...

    African Journals Online (AJOL)

    Hassan Abdelsalam

    2015-12-18

    Dec 18, 2015 ... 14 patients did not have a MDCT and proceeded straight to angiography;. 6 of them showed active bleeding on angiography. Conclusion: MDCT is an excellent technique before angiography and embolization in cases with acute gastrointestinal bleeding. Transcatheter embolization is an effective tool for ...

  3. Digital subtraction angiography of the heart and lungs

    International Nuclear Information System (INIS)

    Moodie, D.S.; Yiannikas, J.

    1986-01-01

    This book contains 12 chapters. Some of the chapter titles are: Physical Principles of Cardiac Digital Subtraction Angiography, The Use of Intravenous Digital Subtraction Angiography in Evaluating Patients with Complex Congenital Heart Disease, Exercise Intravenous Digital Subtraction Angiograpny, Cardiomyopathic and Cardiac Neoplastic Disease, Digital Subtraction Angiography in the Catheterization Laboratory, and Cardiac Digital Subtraction Angiography - Future Directions

  4. Application of OCT angiography in ophthalmology

    Directory of Open Access Journals (Sweden)

    Ai-Ping Yang

    2017-11-01

    Full Text Available Optical coherence tomography angiography(OCTAis a new technology of angiography in recent years. In addition to the advantages of traditional OCT, it can observe blood flow in different retinal and choroidal segmentation slab. By using the pseudo-color, abnormal vascular structure can be distinguished from normal vascular structure of the retina. Dye injection is not needed with OCTA, which is different from fundus fluorescein angiography(FFAand indocyanine green angiography(ICGA. OCTA provides more and more accurate blood flow information. However, like other biometric technology, OCTA has its limitations and shortcomings. This review will analyze and summarize the operating principle of OCTA, its application in ophthalmology, as well as its advantages and limitations.

  5. Anti-diabetic effect of amorphastilbol through PPARα/γ dual activation in db/db mice

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Woojung; Ham, Jungyeob; Kwon, Hak Cheol [Natural Medicine Center, KIST Gangneung Institute, Gangneung 210-340 (Korea, Republic of); Kim, Yong Kee, E-mail: yksnbk@sookmyung.ac.kr [College of Pharmacy, Sookmyung Women’s University, Seoul 140-742 (Korea, Republic of); Kim, Su-Nam, E-mail: snkim@kist.re.kr [Natural Medicine Center, KIST Gangneung Institute, Gangneung 210-340 (Korea, Republic of)

    2013-03-01

    Highlights: ► Amorphastilbol stimulates the transcriptional activities of both PPARα and PPARγ. ► Amorphastilbol improves glucose and lipid impairment in db/db mice. ► There are no side effects, such as hepatomegaly, in amorphastilbol-treated mice. ► Amorphastilbol can be used as a potential therapeutic agent against T2DM. - Abstract: Peroxisome proliferator-activated receptors (PPARs) have been considered as desirable targets for metabolic syndrome treatments, even though their specific agonists have several side effects, including body weight gain, edema, and tissue failure. The effects of amorphastilbol (APH) on glucose- and lipid metabolism were investigated with in vitro 3T3-L1 adipocyte systems and in vivo db/db mice model. APH selectively stimulates the transcriptional activities of both PPARα and PPARγ, which are able to enhance fatty acid oxidation and glucose utilization. Furthermore, APH improves glucose and lipid impairment in db/db mice. More importantly, there are no significant side effects, such as weight gain or hepatomegaly, in APH-treated animals, implying that APH do not adversely affect liver or lipid metabolism. All our data suggest that APH can be used as potential therapeutic agents against type 2 diabetes and related metabolic disorders, including obesity, by enhancing glucose and lipid metabolism.

  6. Anti-diabetic effect of amorphastilbol through PPARα/γ dual activation in db/db mice

    International Nuclear Information System (INIS)

    Lee, Woojung; Ham, Jungyeob; Kwon, Hak Cheol; Kim, Yong Kee; Kim, Su-Nam

    2013-01-01

    Highlights: ► Amorphastilbol stimulates the transcriptional activities of both PPARα and PPARγ. ► Amorphastilbol improves glucose and lipid impairment in db/db mice. ► There are no side effects, such as hepatomegaly, in amorphastilbol-treated mice. ► Amorphastilbol can be used as a potential therapeutic agent against T2DM. - Abstract: Peroxisome proliferator-activated receptors (PPARs) have been considered as desirable targets for metabolic syndrome treatments, even though their specific agonists have several side effects, including body weight gain, edema, and tissue failure. The effects of amorphastilbol (APH) on glucose- and lipid metabolism were investigated with in vitro 3T3-L1 adipocyte systems and in vivo db/db mice model. APH selectively stimulates the transcriptional activities of both PPARα and PPARγ, which are able to enhance fatty acid oxidation and glucose utilization. Furthermore, APH improves glucose and lipid impairment in db/db mice. More importantly, there are no significant side effects, such as weight gain or hepatomegaly, in APH-treated animals, implying that APH do not adversely affect liver or lipid metabolism. All our data suggest that APH can be used as potential therapeutic agents against type 2 diabetes and related metabolic disorders, including obesity, by enhancing glucose and lipid metabolism

  7. Catheter Angiography

    Medline Plus

    Full Text Available ... medical test that helps physicians diagnose and treat medical conditions. Angiography uses one of three imaging technologies and, in most cases, a contrast material injection ...

  8. Noncontrast-enhanced magnetic resonance renal angiography using a repetitive artery and venous labelling technique at 3 T: comparison with contrast-enhanced magnetic resonance angiography in subjects with normal renal function.

    Science.gov (United States)

    Park, Sung Yoon; Kim, Chan Kyo; Kim, EunJu; Park, Byung Kwan

    2015-02-01

    To investigate the feasibility of noncontrast-enhanced MR angiography (NC-MRA) using the repetitive artery and venous labelling (RAVEL) technique to evaluate renal arteries compared to contrast-enhanced MR angiography (CE-MRA). Twenty-five subjects with normal renal function underwent NC-MRA using a RAVEL technique and CE-MRA at 3 T. Two independent readers analysed the MRA images. Image quality, number of renal arteries, presence or absence of an early branching vessel, and diameter of the main renal arteries were evaluated. The overall image quality of NC-MRA was fair or greater in 88% of right and 92% of left renal arteries, while it was 96% in both sides with CE-MRA. On NC-MRA, the number of renal arteries in all subjects was perfectly predicted by both readers. Sensitivity and specificity for predicting early branching vessels were 82% and 100% for reader 1 and 82% and 95% for reader 2. Inter-modality agreement for comparing the diameters of main renal arteries was good or excellent at all segments for both readers. Inter-reader agreement was moderate or good at all segments except at the right distal segment on NC-MRA. NC-MRA with the RAVEL technique at 3 T may have comparable diagnostic feasibility for evaluating renal arteries compared to CE-MRA. • Accurate pre-treatment evaluation of renal artery anatomy helps clinical decision-making. • NC-MRA using RAVEL offers acceptable imaging quality for renal artery evaluation. • The 3 T RAVEL technique provides excellent diagnostic performance for renal artery evaluation. • The 3 T RAVEL technique may be an alternative to contrast-enhanced MRA.

  9. Mitigation Emission Strategy Based on Resonances from a Power Inverter System in Electric Vehicles

    Directory of Open Access Journals (Sweden)

    Li Zhai

    2016-05-01

    responsible elements were determined by the calculation through the equivalent circuits. A combination of mitigation strategies including adding common-mode (CM ferrite chokes through the Y-caps and the AC bus bar was designed to mitigate the resonances at 6 MHz, 11 MHz, and 26 MHz related to the CM conducted emission by IGBT switching and the radiated emission of the AC cable. The values of Z11 decreased respectively by 15 dB at 6 MHz, 0.4 dB at 11 MHz, and 11.5 dB at 26 MHz and the values of S21 decreased respectively by 8.6 dB at 6 MHz, 7 dB at 11 MHz, and 6.3 dB at 26 MHz. An equivalent model of the power inverter system for real-time simulation in time domain was built to validate the mitigation strategy in simulation software PSPICE.

  10. Getting Started with CouchDB

    CERN Document Server

    Brown, MC

    2012-01-01

    CouchDB is a new breed of database for the Internet, geared to meet the needs of today's dynamic web applications. With this concise introduction, you'll learn how CouchDB's simple model for storing, processing, and accessing data makes it ideal for the type of data and rapid response users now demand from your applications-and how easy CouchDB is to set up, deploy, maintain, and scale. The code-packed examples in this book will help you learn how to work with documents, populate a simple database, replicate data from one database to another, and a host of other tasks. Install CouchDB on Lin

  11. Coronary CT angiography: Diagnostic value and clinical challenges.

    Science.gov (United States)

    Sabarudin, Akmal; Sun, Zhonghua

    2013-12-26

    Coronary computed tomography (CT) angiography has been increasingly used in the diagnosis of coronary artery disease due to improved spatial and temporal resolution with high diagnostic value being reported when compared to invasive coronary angiography. Diagnostic performance of coronary CT angiography has been significantly improved with the technological developments in multislice CT scanners from the early generation of 4-slice CT to the latest 320- slice CT scanners. Despite the promising diagnostic value, coronary CT angiography is still limited in some areas, such as inferior temporal resolution, motion-related artifacts and high false positive results due to severe calcification. The aim of this review is to present an overview of the technical developments of multislice CT and diagnostic value of coronary CT angiography in coronary artery disease based on different generations of multislice CT scanners. Prognostic value of coronary CT angiography in coronary artery disease is also discussed, while limitations and challenges of coronary CT angiography are highlighted.

  12. Getting started with MariaDB

    CERN Document Server

    Bartholomew, Daniel

    2013-01-01

    A practical, hands-on, beginner-friendly guide to installing and using MariaDB.Getting Started with MariaDB is for anyone who wants to learn more about databases in general or MariaDB in particular. No prior database experience is required. It is assumed that you have basic knowledge of software installation, editing files with a text editor, and using the command line and terminal.

  13. Feasibility of MR-guided angioplasty of femoral artery stenoses using real-time imaging and intraarterial contrast-enhanced MR angiography

    International Nuclear Information System (INIS)

    Paetzel, C.; Zorger, N.; Bachthaler, M.; Voelk, M.; Seitz, J.; Herold, T.; Feuerbach, S.; Lenhart, M.; Nitz, W.R.

    2004-01-01

    Purpose: To show the feasibility of magnetic resonance (MR) for guided interventional therapy of femoral and popliteal artery stenoses with commercially available materials supported by MR real-time imaging and intraarterial MR angiography. Materials and Methods: Three patients (1 female, 2 male), suffering from symptomatic arterial occlusive disease with stenoses of the femoral (n=2) or popliteal (n=1) arteries were included. Intraarterial digital subtraction angiography was performed in each patient pre- and post-interventionally as standard of reference to quantify stenoses. The degree of the stenoses reached from 71-88%. The MR images were acquired on a 1.5 T MR scanner (Magnetom Sonata; Siemens, Erlangen, Germany). For MR-angiography, a Flash 3D sequence was utilized following injection of 5 mL diluted gadodiamide (Omniscan; Amersham Buchler, Braunschweig, Germany) via the arterial access. Two maximum intensity projections (MIP) were used as road maps and localizer for the interactive positioning of a continuously running 2D-FLASH sequence with a temporal solution of 2 images per second. During the intervention, an MR compatible monitor provided the image display inside the scanner room. Safety guidelines were followed during imaging in the presence of a conductive guidewire. The lesion was crossed by a commercially available balloon catheter (Wanda, Boston Scientific; Ratingen, Germany), which was mounted on a 0.035'' guidewire (Terumo; Leuven, Belgium). The visibility was provided by radiopaque markers embedded in the balloon and was improved by injection of 1 mL gadodiamide into the balloon. After dilation, the result was checked by intraarterial MR angiography and catheter angiography. Results: The stenoses could be correctly localized by intraarterial MR angiography. There was complete correlation between intraarterial MR angiography and digital subtraction angiography. The combination of guidewire and balloon was visible and the balloon was placed

  14. Contrast-enhanced MR angiography in Leriche's syndrome

    International Nuclear Information System (INIS)

    Link, J.; Steffens, J.C.; Brossmann, J.; Heller, M.; Loose, R.

    1998-01-01

    Purpose: To determine the usefulness of contrast-enhanced MR angiography for the diagnosis of Leriche's syndrome. Material and methods: Leriche's syndrome was seen in 7 patients via DSA. In [dition, contrast-enhanced MR angiography was performed (T R 7.8 ms/T E 2.1 ms, flip angle 30 , slab thickness 116 mm, slice thickness 1.82 mm, 64 partitions, FOV 500x438 mm, matrix 224x512). Results: Diagnosis of Leriche's syndrome was possible by contrast-enhanced MR angiography in each case. Visualisation of the femoral arteries was not possible in two patients by intraarterial DSA, in three other patients there was an insufficient contrast in the femoral arteries with DSA. Contrast-enhanced MR angiography revealed good visualisation of the femoral arteries in these patients. In [dition, contrast-enhanced MR angiography allowed complete visualisation of the patent lower limb arteries. In intraarterial DSA visualisation of the lower limb arteries was achieved reached in only one patient, but was incomplete. Conclusion: Contrast-enhanced MR angiography yielded the correct diagnosis of Leriche's syndrome in all 7 patients. Contrast-enhanced MR angiography was superior to DSA in the assessment of the distal run-off vessels in five of seven patients. (orig.) [de

  15. Qing-Hua Granule induces GLP-1 secretion via bitter taste receptor in db/db mice.

    Science.gov (United States)

    Li, Junyan; Xu, Jie; Hou, Ruifang; Jin, Xin; Wang, Jingyi; Yang, Na; Yang, Li; Liu, Li; Tao, Feng; Lu, Hao

    2017-05-01

    Qing-Hua Granule (QHG), the modified formulation of a classical Chinese prescription named Gegen Qinlian Decoction, was clinically employed to treat type 2 diabetes mellitus (T2DM) through regulation of glucagon-like peptide-1 (GLP-1). However, the potential mechanism is unknown. We investigate whether QHG induces GLP-1 secretion via activation of bitter taste receptor (TAS2R) pathway in the gastrointestinal tract of db/db mice. The db/db mice were intragastrically (i.g.) administered QHG (low/medium/high dose) once daily for 8 weeks. GLP-1 secretion was evaluated. The bitter receptor signaling pathway, which regulates GLP-1 secretion, including TAS2R5 (a subtype of TAS2R), α-gustducin (Gαgust), 1-phosphatidylinositol-4, 5-bisphosphate phosphodiesterase beta-2 (PLCβ2), transient receptor potential cation channel subfamily M member 5 (TRPM5), was assessed by quantitative real-time polymerase chain reaction (qRT-PCR), Western blot and immunohistochemistry (IHC). The biochemical observations of ileum and pancreas tissue were detected histopathologically. Acquity Ultra Performance LCTM - Micromass ZQ 2000 (UPLC-MS) was used for the phytochemical analysis. QHG exhibited significant and dose-dependent effect on GLP-1 secretion in db/db mice, along with significant up-regulation of TAS2R5 mRNA level and activation of TAS2R pathway (p<0.05). In addition, QHG improved the histopathological structure of ileum and pancreatic tissue. Seventeen compounds were identified in QHG. In conclusion, QHG induces GLP-1 secretion in db/db mice, most likely through the bitter taste receptor pathway. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  16. MongoDB and PHP

    CERN Document Server

    Francia, Steve

    2012-01-01

    What would happen if you optimized a data store for the operations application developers actually use? You'd arrive at MongoDB, the reliable document-oriented database. With this concise guide, you'll learn how to build elegant database applications with MongoDB and PHP. Written by the Chief Solutions Architect at 10gen-the company that develops and supports this open source database-this book takes you through MongoDB basics such as queries, read-write operations, and administration, and then dives into MapReduce, sharding, and other advanced topics. Get out of the relational database rut,

  17. Intraarterial digital subtraction angiography after coronary bypass surgery - an alternative to coronary angiography

    International Nuclear Information System (INIS)

    Hauenstein, H.K.; Roeren, T.; Schlosser, V.; Urbani, B.

    1985-01-01

    Intraarterial digital subtraction angiography after coronary bypass surgery - an alternative to coronary angiography. Intraarterial DSA is a suitable method for early postoperative control of coronary artery bypass grafts. Small quantities of contrast media with low iodine content are injected into the aortic root. Investigations can be carried out with a routine fluoroscopic and digital equipment; additional cine-technique and analogue memory disc are not necessary. At an image rate of 3/s the bypass anastomoses can be exactly visualized in 75%, whereas diagnostic information was not sufficient in only 4% of all cases. The use of modern F-5-catheters and the nonselective injection make this method a less invasive alternative to coronary angiography. It is paticularly useful in evaluation of short- and long-term results. (orig.) [de

  18. Effect of zinc nutriture on tissue zinc (Zn) in the diabetic C57BL/KsJ db/db mouse

    International Nuclear Information System (INIS)

    Donaldson, D.L.; Smith, C.C.; Walker, M.S.; Yunice, A.A.; Rennert, O.M.

    1986-01-01

    The genetically obese diabetic db/db mouse has been reported to have low serum (S) and femur (F) Zn concentrations. In order to examine whether this animal model is predisposed to dietary Zn deficiency, they measured tissue Zn concentrations (conc.) in db/db, heterozygous db/m, and homozygous m/m control mice fed either a zinc deficient diet (2 ppm Zn) ad libitum or a zinc adequate diet (20 ppm Zn) either ad libitum or in restricted amounts (equal to that consumed by mice on the 2 ppm Zn diet) for 12 wks. The results were analyzed by analysis of variance for a completely randomized 3X3 design. Similar clinical manifestations of Zn deficiency were seen in mice of all 3 genotypes after 8-10 weeks on 2 ppm Zn. S Zn(p=0.0001) and F Zn conc.(p=0.0001) and content(p=0.0001) of those 3 groups showed similar marked reductions. S Zn was not reduced in db/db mice fed 20 ppm Zn. F Zn conc. was mildly reduced in these mice but not to the extent observed in mice fed 2 ppm Zn. Liver (L) Zn conc. was not affected by either genotype or diet, but total L Zn(p=0.0001) was greater in db/db mice due to their larger L weight. Kidney (K) Zn conc.(p=0.0001) of db/db mice was slightly but significantly decreased, but their total K Zn content(p=0.0001) was increased due to their greater K weights. They conclude that, in spite of its having a decreased F Zn conc. and content, the db/db mouse does not appear to be particularly susceptible to dietary Zn deficiency

  19. Diagnostic and interventional angiography of superior mesenteric artery

    Energy Technology Data Exchange (ETDEWEB)

    Simonetti, G; Urigo, F; Canalis, G C; Guazzaroni, M; Caboni, M; Rossi, P; Passariello, R

    1986-01-01

    The widespread diffusion of digital imaging progressivaly reduces the indications to conventional angiography in all vascular districts. On the contrary, angiography of mesenteric arteries still works as a valid complementary diagnostic tool in granulomatous and neoplastic lesions of ileum. Today, in selected patients, angiography is the first diagnostic approach to vascular ischemic and hemorrhagic pathology of ileum; timely resort to interventional angiography improve a dramatic prognosis. 70 refs.

  20. Prospective comparison of MR angiography and color duplex US with conventional angiography for peripheral arterial occlusive disease

    International Nuclear Information System (INIS)

    Mulligan, S.A.; Matsuda, T.; Lanzer, P.; Gross, G.; Routh, W.; Keller, F.; Koslin, D.B.; Berland, L.; Fields, M.; Doyle, M.; Cranney, G.; Lee, J.; Pohost, G.

    1990-01-01

    This paper evaluates color Doppler US (CDUS) and MR angiographic (MRA) assessment of peripheral vascular disease of the lower extremities, using blinded prospective comparison with conventional angiography. Conventional angiography, two-dimensional inflow MRA, and CDUS were performed in 12 patients. Four diagnostic categories were used to grade arterial lesions by evaluating peak velocity. Revascularization interventions were planned by the vascular surgeon, blinded from the imaging method utilized and from data derived from CDUS, MRA, and conventional angiography

  1. Hemifacial spasm; The value of vertebral angiography

    International Nuclear Information System (INIS)

    Yang, Hak Seok; Kim, Myung Soon; Han, Yong Pyo

    1992-01-01

    In order to evaluate the value of vertebral angiography in assesment of hemifacial spasm, We reviewed retrospectively the vertebral angiography of 28 patients (30 cases) with surgically proved hemifacial spasm but normal CT scans of posterior fossa. There were 9 males and 19 females. Angiography revealed vascular focus of hemifacial spasm located at anterior inferior cerebellar artery , posterior inferior cerebellar artery, and vertebral artery in 19, 9, and 2 cases respectively. Right side was involved in 20 cases. All involved vessels were elongated, tortuous, and dilated. In conclusion, vertebral angiography was valuable in evaluating hemifacial spasm of vascular origin in the posterior fossa

  2. Catheter Angiography

    Medline Plus

    Full Text Available ... to your primary care or referring physician , who will discuss the results with you. top of page What are the benefits vs. risks? Benefits Angiography may eliminate the need ...

  3. MR angiography and the preoperative evaluation of renal arteries

    International Nuclear Information System (INIS)

    Nakahara, Kimitoshi; Yokoyama, Hiroshi; Tsuji, Yuji

    2001-01-01

    To determine the accuracy of gadolinium-enhanced, three-dimensional, magnetic resonance angiography (3D-MRA) in the visualization of the arterial anatomy of the kidney, we compared preoperative 3D-MRA results with surgical findings in 37 patients who underwent renal surgery. 3D-MRA findings were confirmed surgically in 30 of these patients (81%). However, 4 of 7 accessory renal arteries were missed by this imaging technique. Furthermore, 3D-MRA failed to visualize renal arteries in all of the three atrophic kidneys. 3D-MRA is a safe and reliable procedure for the preoperative evaluation of renal arteries. However, the depiction of smaller renal arteries, such as accessory and atrophic arteries, is less accurate. (author)

  4. MR angiography and the preoperative evaluation of renal arteries

    Energy Technology Data Exchange (ETDEWEB)

    Nakahara, Kimitoshi; Yokoyama, Hiroshi; Tsuji, Yuji [Fukuoka Univ. (Japan). School of Medicine

    2001-04-01

    To determine the accuracy of gadolinium-enhanced, three-dimensional, magnetic resonance angiography (3D-MRA) in the visualization of the arterial anatomy of the kidney, we compared preoperative 3D-MRA results with surgical findings in 37 patients who underwent renal surgery. 3D-MRA findings were confirmed surgically in 30 of these patients (81%). However, 4 of 7 accessory renal arteries were missed by this imaging technique. Furthermore, 3D-MRA failed to visualize renal arteries in all of the three atrophic kidneys. 3D-MRA is a safe and reliable procedure for the preoperative evaluation of renal arteries. However, the depiction of smaller renal arteries, such as accessory and atrophic arteries, is less accurate. (author)

  5. Computed tomography versus invasive coronary angiography

    DEFF Research Database (Denmark)

    Napp, Adriane E.; Haase, Robert; Laule, Michael

    2017-01-01

    Objectives: More than 3.5 million invasive coronary angiographies (ICA) are performed in Europe annually. Approximately 2 million of these invasive procedures might be reduced by noninvasive tests because no coronary intervention is performed. Computed tomography (CT) is the most accurate...... angiography (ICA) is the reference standard for detection of CAD.• Noninvasive computed tomography angiography excludes CAD with high sensitivity.• CT may effectively reduce the approximately 2 million negative ICAs in Europe.• DISCHARGE addresses this hypothesis in patients with low-to-intermediate pretest...

  6. Digital subtraction angiography for breast cancer

    International Nuclear Information System (INIS)

    Tsurumi, Kiyohiko; Okuyama, Nobuo

    1987-01-01

    We performed digital subtraction angiography (DSA) on 42 patients with breast diseases to investigate its efficiency. As a result we came to the following conclusions: 1. The sensitivity was well evaluated in intraarterial digital subtraction angiography (IA-DSA) of breast. 2. IA-DSA could diagnose difficult cases like cancer which had undergone augmentation mammoplasty, or like Paget's disease and others. 3. DSA was a safe examination method. 4. The sensitivity of IA-DSA of breast cancer is superior to intravenous digital subtraction angiography (IV-DSA). (author)

  7. Catheter Angiography

    Medline Plus

    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician Resources Professions Site Index A-Z Catheter Angiography ...

  8. Diagnosis of Popliteal Venous Entrapment Syndrome by Magnetic Resonance Imaging Using Blood-Pool Contrast Agents

    International Nuclear Information System (INIS)

    Beitzke, Dietrich; Wolf, Florian; Juelg, Gregor; Lammer, Johannes; Loewe, Christian

    2011-01-01

    Popliteal vascular entrapment syndrome is caused by aberrations or hypertrophy of the gastrocnemius muscles, which compress the neurovascular structures of the popliteal fossa, leading to symptoms of vascular and degeneration as well as aneurysm formation. Imaging of popliteal vascular entrapment may be performed with ultrasound, magnetic resonance imaging (MRI), computed tomography angiography, and conventional angiography. The use of blood-pool contrast agents in MRI when popliteal vascular entrapment is suspected offers the possibility to perform vascular imaging with first-pass magnetic resonance angiographic, high-resolution, steady-state imaging and allows functional tests all within one examination with a single dose of contrast agent. We present imaging findings in a case of symptomatic popliteal vein entrapment diagnosed by the use of blood pool contrast-enhanced MRI.

  9. Angiography in portal hypertension

    Energy Technology Data Exchange (ETDEWEB)

    Zeitler, E

    1982-04-05

    We report on the cooperative possibilities the radiologist has as to diagnosis and therapy of portal hypertension. The catheter angiography allows to make a differentiation between pre- and intrahepatic bloc and the localization of bleeding esophagus varices. Only after all endoscopic measures with sclerotherapy and Laser coagulation have failed, catheter angiography will be carried out as a therapeutic measure. The future development, however, will give the opportunity to a series of therapeutic attempts on the field of interventional radiology.

  10. MR-angiography in vasculitis and benign angiopathy of the central nervous system

    International Nuclear Information System (INIS)

    Schlueter, A.; Hirsch, W.; Jassoy, A.; Behrmann, C.; Spielmann, R.P.; Kornhuber, M.; Keysser, G.

    2001-01-01

    To evaluate TOF 3D magnetic resonance angiography (MRA) of the intracranial arteries in patients with vasculitis or vasculitis-like benign angiopathy of the central nervous system (CNS). Method: The results of MRA in 20 patients with clinically and radiographically proven vasculitis (17/20) or vasculitis-like benign angiopathy (3/20) of the CNS were retrospectively analysed. Patients with hyperintense lesions of more than 3 mm on T 2 -weighted MRI images were included in this trial. An inflammatory, embolic, neurodegenerative or metastatic origin of these lesions was excluded by extensive clinical studies. For the MR-examination a TOF 3D FISP sequence was used on a 1.5 T imager. Results: MRA showed characteristic changes for vasculitis or angiopathy in 15 of 20 patients (75%). Conclusions: In patients suspected of having a vasculitis or vasculitis-like angiopathy, MRA is recommended as a non-invasive modality. If the results of MRI and extensive clinical studies are carefully correlated, MRA may substitute conventional angiography in cases with typical vascular changes. (orig.) [de

  11. Dynamic magnetic resonance angiography of the arteries of the hand. A comparison between an extracellular and an intravascular contrast agent

    International Nuclear Information System (INIS)

    Reisinger, Clemens; Gluecker, Thomas; Jacob, Augustinus Ludwig; Bongartz, Georg; Bilecen, Deniz

    2009-01-01

    The purpose of this study was to compare the image quality of the intravascular contrast agent gadofosveset with the extracellular contrast agent gadoterate meglumine in time-resolved three-dimensional magnetic resonance (MR) angiography of the human arteries of the hand. The value of cuff compression technique for suppression of venous enhancement for both contrast agents was also investigated. Three-dimensional MR angiograms of both hands of 11 healthy volunteers were acquired for each contrast agent at 1.5-T, while subsystolic cuff compression was applied at one side. Quantitative and qualitative evaluation were performed and analyzed with Student's t-test. Visualization of vessels was superior in the images acquired with gadofosveset, especially in the late phases. Quantitative and qualitative evaluation showed significantly higher values for gadofosveset. The cuff compression at the lower arm proved to be an effective method to enhance arterial vessels. In conclusion the blood pool agent gadofosveset is superior for the dynamic imaging of the vessels of the hand when compared with the extracellular contrast agent gadoterate meglumine. To fully utilize the advantages of intravascular contrast agents, venous overlay has to be delayed or reduced, which can be achieved effectively by subsystolic lower arm cuff compression. (orig.)

  12. Comparison of CO2 DSA and conventional angiography using non-ionic contrast media in lower extremity angiography

    International Nuclear Information System (INIS)

    Kim, Jae Kyu; Park, Sung Jae; Koh, Seok Wan; Seo, Jeong Jin; Kang, Heoung Keun; Chung, Hyon De

    1994-01-01

    The purpose of this study is to compare CO 2 DSA and nonionic contrast media angiography in respect to the quality of the opacification of collaterals and incidence of side-effects in peripheral occlusive arterial disease. Sixteen patients who were suspected to have peripheral occlusive arterial disease were performed angiography with nonionic contrast media and CO 2 at the same location with the same catheter. The causes of the lesions were atherosclerosis(n=7) and Buerger's disease(n=9). CO 2 DSA was compared with nonionic contrast media angiography in respect to the quality of image in the diagnosis of the lesions, opacifications of collaterals and side-effects. In atherosclerosis; quality of the images of CO 2 DSA was same as that of nonionic contrast media angiography in 6 patients and was poor in 1 patient; opacifications of collaterals of CO 2 DSA were same as that of nonionic contrast media angiography in 5 patients and was poor in 2 patients. In Buerger's disease; quality of the images of CO 2 DSA was same as that of nonionic contrast media angiography in 2 patients and was poor in 7 patients; opacifications of collaterals of CO 2 DSA were same as that of nonionic contrast media angiography in 1 patient and was poor in 8 patients. Leg pain was the only side-effect after CO 2 injection occurring in 4 out of 16 patients. CO 2 could be used as safe contrast media in patient with risk factors for nonionic contrast media and for diagnosis of the atherosclerosis in lower extremity. For the procedures such as vascular intervention requiring large amount of contrast media CO 2 could effectively replace nonionic contrast media

  13. Videodensitometric quantitative angiography after coronary balloon angioplasty, compared to edge-detection quantitative angiography and intracoronary ultrasound imaging

    NARCIS (Netherlands)

    Peters, R. J.; Kok, W. E.; Pasterkamp, G.; von Birgelen, C.; Prins, M. [=Martin H.; Serruys, P. W.

    2000-01-01

    AIMS: To assess the value of videodensitometric quantification of the coronary lumen after angioplasty by comparison to two other techniques of coronary artery lumen quantification. METHODS AND RESULTS: Videodensitometric quantitative angiography, edge detection quantitative angiography and 30 MHz

  14. AFM-based detection of glycocalyx degradation and endothelial stiffening in the db/db mouse model of diabetes.

    Science.gov (United States)

    Targosz-Korecka, Marta; Jaglarz, Magdalena; Malek-Zietek, Katarzyna E; Gregorius, Aleksandra; Zakrzewska, Agnieszka; Sitek, Barbara; Rajfur, Zenon; Chlopicki, Stefan; Szymonski, Marek

    2017-11-21

    Degradation of the glycocalyx and stiffening of endothelium are important pathophysiological components of endothelial dysfunction. However, to our knowledge, these events have not been investigated in tandem in experimental diabetes. Here, the mechanical properties of the glycocalyx and endothelium in ex vivo mouse aorta were determined simultaneously in indentation experiments with an atomic force microscope (AFM) for diabetic db/db and control db/+ mice at ages of 11-19 weeks. To analyze highly heterogeneous aorta samples, we developed a tailored classification procedure of indentation data based on a bi-layer brush model supplemented with Hertz model for quantification of nanomechanics of endothelial regions with and without the glycocalyx surface. In db/db mice, marked endothelial stiffening and reduced glycocalyx coverage were present already in 11-week-old mice and persisted in older animals. In contrast, reduction of the effective glycocalyx length was progressive and was most pronounced in 19-week-old db/db mice. The reduction of the glycocalyx length correlated with an increasing level of glycated haemoglobin and decreased endothelial NO production. In conclusion, AFM nanoindentation analysis revealed that stiffening of endothelial cells and diminished glycocalyx coverage occurred in early diabetes and were followed by the reduction of the glycocalyx length that correlated with diabetes progression.

  15. On-Chip All-Optical Passive 3.55 Gbit/s NRZ-to-PRZ Format Conversion Using a High-Q Silicon-Based Microring Resonator

    International Nuclear Information System (INIS)

    Yao, Zhai; Shao-Wu, Chen; Guang-Hui, Ren

    2010-01-01

    We report the experimental result of all-optical passive 3.55 Gbit/s non-return-to-zero (NRZ) to pseudo-return-to-zero (PRZ) format conversion using a high-quality-factor (Q-factor) silicon-based microring resonator notch filter on chip. The silicon-based microring resonator has 23800 Q-factor and 22 dB extinction ratio (ER), and the PRZ signals has about 108ps width and 4.98 dB ER

  16. Catheter Angiography

    Medline Plus

    Full Text Available ... medical conditions. Angiography uses one of three imaging technologies and, in most cases, a contrast material injection ... congenital abnormalities in blood vessels, especially arteries in children (e.g., malformations in the heart or other ...

  17. Catheter Angiography

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    Full Text Available ... imaging (MRI) In catheter angiography, a thin plastic tube, called a catheter , is inserted into an artery ... examined, a contrast material is injected through the tube and images are captured using a small dose ...

  18. Catheter Angiography

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    Full Text Available ... accurate pictures of the blood vessels and may eliminate the need for surgery. Tell your doctor if ... are the benefits vs. risks? Benefits Angiography may eliminate the need for surgery. If surgery remains necessary, ...

  19. Catheter Angiography

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    Full Text Available ... spaghetti. top of page How does the procedure work? Catheter angiography works much the same as a ... angiogram may be performed in less than an hour; however, it may last several hours. top of ...

  20. Catheter Angiography

    Medline Plus

    Full Text Available ... medical conditions. Angiography uses one of three imaging technologies and, in most cases, a contrast material injection ... a tendency to bleed. top of page Additional Information and Resources Society of Interventional Radiology (SIR) - Patient ...

  1. Catheter Angiography

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    Full Text Available ... diagnosis and treatment in a single procedure. An example is finding an area of severe arterial narrowing, ... contrast material, your radiologist may advise that you take special medication for 24 hours before catheter angiography ...

  2. Catheter Angiography

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    Full Text Available ... possible to combine diagnosis and treatment in a single procedure. Catheter angiography produces very detailed, clear and ... possible to combine diagnosis and treatment in a single procedure. An example is finding an area of ...

  3. Catheter Angiography

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    Full Text Available ... blood flow to the brain and cause a stroke. identify a small aneurysm or arteriovenous malformation (abnormal ... you. top of page What are the benefits vs. risks? Benefits Angiography may eliminate the need for ...

  4. Catheter Angiography

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    Full Text Available ... iodine. If angiography is essential, a variety of methods is used to decrease risk of allergy: You ... radiation oncology provider in your community, you can search the ACR-accredited facilities database . This website does ...

  5. Catheter Angiography

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    Full Text Available ... of a catheter makes it possible to combine diagnosis and treatment in a single procedure. Catheter angiography ... of a catheter makes it possible to combine diagnosis and treatment in a single procedure. An example ...

  6. Catheter Angiography

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    Full Text Available ... examine blood vessels in key areas of the body for abnormalities such as aneurysms and disease such ... to produce pictures of blood vessels in the body. Angiography is performed using: x-rays with catheters ...

  7. Catheter Angiography

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    Full Text Available ... rare, and radiology departments are well-equipped to deal with them. There is a small risk that ... standard x-ray contrast. Catheter angiography should be done very cautiously—if at all—in patients who ...

  8. Catheter Angiography

    Medline Plus

    Full Text Available ... medical conditions. Angiography uses one of three imaging technologies and, in most cases, a contrast material injection ... possible charges you will incur. Web page review process: This Web page is reviewed regularly by a ...

  9. Catheter Angiography

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    Full Text Available ... few millimeters) in the skin where the catheter can be inserted into an artery. The catheter is ... need for surgery. If surgery remains necessary, it can be performed more accurately. Catheter angiography presents a ...

  10. Catheter Angiography

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    Full Text Available ... 20 minutes (or by using a special closure device). When the examination is complete, you may be ... contrast material, your radiologist may advise that you take special medication for 24 hours before catheter angiography ...

  11. Catheter Angiography

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    Full Text Available ... rays ). top of page What are some common uses of the procedure? Catheter angiography is used to ... community, you can search the ACR-accredited facilities database . This website does not provide cost information. The ...

  12. Catheter Angiography

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    Full Text Available ... medical conditions. Angiography uses one of three imaging technologies and, in most cases, a contrast material injection ... far outweighs the risk. If you have a history of allergy to x-ray contrast material, your ...

  13. Catheter Angiography

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    Full Text Available ... spaghetti. top of page How does the procedure work? Catheter angiography works much the same as a ... and x-rays. Manufacturers of intravenous contrast indicate mothers should not breastfeed their babies for 24-48 ...

  14. Catheter Angiography

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    Full Text Available ... Catheter angiography uses a catheter, x-ray imaging guidance and an injection of contrast material to examine ... removable dental appliances, eye glasses and any metal objects or clothing that might interfere with the x- ...

  15. Catheter Angiography

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    Full Text Available ... medical conditions. Angiography uses one of three imaging technologies and, in most cases, a contrast material injection ... American College of Radiology (ACR) and the European Society of Urogenital Radiology note that the available data ...

  16. Catheter Angiography

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    Full Text Available ... spaghetti. top of page How does the procedure work? Catheter angiography works much the same as a ... possible to combine diagnosis and treatment in a single procedure. An example is finding an area of ...

  17. Catheter Angiography

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    Full Text Available ... most cases, the kidneys will regain their normal function within five to seven days. Rarely, the catheter ... limitations of Catheter Angiography? Patients with impaired kidney function, especially those who also have diabetes, are not ...

  18. Catheter Angiography

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    Full Text Available ... medical conditions. Angiography uses one of three imaging technologies and, in most cases, a contrast material injection ... in key areas of the body, including the: brain neck heart chest abdomen (such as the kidneys ...

  19. Catheter Angiography

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    Full Text Available ... medical conditions. Angiography uses one of three imaging technologies and, in most cases, a contrast material injection ... The video is produced by the x-ray machine and a detector that is suspended over a ...

  20. Catheter Angiography

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    Full Text Available ... top of page What are the benefits vs. risks? Benefits Angiography may eliminate the need for surgery. ... in the typical diagnostic range for this exam. Risks There is always a slight chance of cancer ...

  1. Catheter Angiography

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    Full Text Available ... serious allergic reaction to contrast materials that contain iodine is extremely rare, and radiology departments are well- ... having a reaction to contrast materials that contain iodine. If angiography is essential, a variety of methods ...

  2. Dual and tri-band bandpass filters based on novel Π-shaped resonator

    Science.gov (United States)

    Xiao, Jian-Kang; Zhu, Wen-Jun; Zhao, Wei

    2014-05-01

    A novel Π-shaped resonator is proposed, and compact dual-band and tri-band bandpass filters that meet IEEE 802.11 application requirements by using the new resonator are designed. The dual-band bandpass filter centres at 2.45 and 5.6 GHz with a simulated passband insertion loss of no more than 0.8 dB, and the tri-band bandpass filter which is got by two-path coupling achieves simulated passband insertion loss of no more than 1.1 dB. The new designs are demonstrated by experiment. The new filters have advantages of simple and compact structures, low passband insertion losses, good frequency selectivity and miniature circuit sizes. All these have prospect to be applied in future wireless communication systems.

  3. Collateral vessels on magnetic resonance angiography in endovascular-treated acute ischemic stroke patients associated with clinical outcomes.

    Science.gov (United States)

    Jiang, Liang; Su, Hao-Bo; Zhang, Ying-Dong; Zhou, Jun-Shan; Geng, Wen; Chen, Huiyou; Xu, Quan; Yin, Xindao; Chen, Yu-Chen

    2017-10-06

    Collateral vessels were considered to be related with outcome in endovascular-treated acute ischemic stroke patients. This study aimed to evaluate whether the collateral vessels on magnetic resonance angiography (MRA) could predict the clinical outcome. Acute stroke patients with internal carotid artery or middle cerebral artery occlusion within 6 hours of symptom onset were included. All patients underwent MRI and received endovascular treatment. The collateral circulations at the Sylvian fissure and the leptomeningeal convexity were evaluated. The preoperative and postoperative infarct volume was measured. The clinical outcome was evaluated by mRS score at 3 months after stroke. Of 55 patients, Cases with insufficient collateral circulation at the Sylvian fissure and leptomeningeal convexity showed that the NIHSS score at arrival and preoperative infarct volume were significantly lower in mRS score of 0-2 (both P collateral status at the leptomeningeal convexity were independent of the clinical outcome at 3 months after stroke (odds ratio (95% confidence interval): 1.094 (1.025-1.168); 9.542 (1.812-50.245) respectively). The change of infarct volume in the group with mRS score of 0-2 was smaller than that with mRS score of 3-6. While multivariate logistic models showed that postoperative infarct volume was non-significant in predicting the clinical outcome after stroke. The extent of collateral circulation at the leptomeningeal convexity may be useful for predicting the functional recovery while the relationship between postoperative infarct volume and clinical outcome still requires for further study.

  4. Angiography in portal hypertension

    International Nuclear Information System (INIS)

    Zeitler, E.

    1982-01-01

    We report on the cooperative possibilities the radiologist has as to diagnosis and therapy of portal hypertension. The catheter angiography allows to make a differentiation between pre- and intrahepatic bloc and the localization of bleeding esophagus varices. Only after all endoscopic measures with sclerotherapy and Laser coagulation have failed, catheter angiography will be carried out as a therapeutic measure. The future development, however, will give the opportunity to a series of therapeutic attempts on the field of interventional radiology. (orig.) [de

  5. Magnetic resonance angiography virtual endoscopy in the assessment of pulmonary veins before radiofrequency ablation procedures for atrial fibrillation

    Energy Technology Data Exchange (ETDEWEB)

    Cirillo, S.; Tosetti, Irene; Giuseppe, M.De; Longo, M.; Regge, D. [Institute for Cancer Research and Treatment (IRCC), Unit of Radiology, Candiolo (Torino) (Italy); Bonamini, R. [University of Torino, Department of Cardiology, Torino (Italy); Gaita, F.; Bianchi, F.; Vivalda, L. [Ospedale Mauriziano Umberto I, Department of Cardiology, Torino (Italy)

    2004-11-01

    Magnetic resonance angiography (MRA) is a safe and non-invasive imaging method that can readily depict the pulmonary veins (PV), whose imaging has acquired momentum with the advent of new techniques for radiofrequency ablation of atrial fibrillation (AF). We evaluated whether virtual endoscopy from 3D MRA images (MRA-VE) is feasible in studying the morphology of PV. Fifty patients with AF underwent pre-ablative MRA (1.5 T). Images were acquired with axial T-2 weighted and 3D-SPGR sequences after intravenous administration of Gd-DTPA and automatic triggering. Postprocessing was performed by an experienced radiologist with maximum intensity projection (MIP) and virtual endoscopy software (Navigator, GEMS). The venoatrial junction was visualized with MRA-VE in 49 of 50 patients (98.0%). Twenty-seven patients (55.1%) had two ostia on both sides, 13 patients (26.5%) had two ostia on the right and a single common ostium on the left, 5 patients (10.2%) had accessory PV and 4 patients (8.2%) had both an accessory right PV and a single common ostium on the left. Flythrough navigation showed the number and spatial disposition of second-order PV branches in 48 out of 49 patients (98.0%). MRA-VE is an excellent tool for at-a-glance visualization of ostia morphology, navigation of second-generation PV branches and easy endoluminal assessment of left atrial structures in pre-ablative imaging. (orig.)

  6. Diagnostic value of 3D time-of-flight magnetic resonance angiography for detecting intracranial aneurysm: a meta-analysis.

    Science.gov (United States)

    HaiFeng, Liu; YongSheng, Xu; YangQin, Xun; Yu, Dou; ShuaiWen, Wang; XingRu, Lu; JunQiang, Lei

    2017-11-01

    This meta-analysis is to comprehensively evaluate the diagnostic performance of three-dimensional time-of-flight magnetic resonance angiography (3D-TOF-MRA) for detecting intracranial aneurysm (IA). PubMed, Embase, Web of Science, and the Cochrane library were systematically searched for retrieving eligible studies. Study inclusion, data extraction, and risk of bias assessment were performed by two researchers independently. Pooled sensitivity (SEN), specificity (SPE), positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), and area under the curve (AUC) were calculated to assess the diagnostic value. In addition, heterogeneity and subgroup analysis were carried out. In total, 18 studies comprising 3463 patients were selected. The results of 3D-TOF-MRA for diagnosing IA were SEN 0.89 (95% CI 0.82-0.94), SPE 0.94 (0.86-0.97), PLR 13.79 (5.92-32.12), NLR 0.11 (0.07-0.19), DOR 121.90 (38.81-382.94), and AUC 0.96 (0.94-0.98), respectively. In the subgroup analysis, studies without subarachnoid hemorrhage (SAH) tend to perform statistical significantly better (P 3D-TOF-MRA had better SEN in aneurysms > 3 mm than the aneurysms ≤ 3 mm in diameter: 0.89 (0.87-0.92) vs. 0.78 (0.71-0.84) with P 3D-TOF-MRA has an excellent diagnostic performance for the overall assessment of IA and may serve as an alternative for further patient management with IA.

  7. Time-Resolved Three-Dimensional Contrast-Enhanced Magnetic Resonance Angiography in Patients with Chronic Expanding and Stable Aortic Dissections

    Directory of Open Access Journals (Sweden)

    Michael Trojan

    2017-01-01

    Full Text Available Objective. To prospectively evaluate our hypothesis that three-dimensional time-resolved contrast-enhanced magnetic resonance angiography (TR-MRA is able to detect hemodynamic alterations in patients with chronic expanding aortic dissection compared to stable aortic dissections. Materials and Methods. 20 patients with chronic or residual aortic dissection in the descending aorta and patent false lumen underwent TR-MRA of the aorta at 1.5 T and repeated follow-up imaging (mean follow-up 5.4 years. 7 patients showed chronic aortic expansion and 13 patients had stable aortic diameters. Regions of interest were placed in the nondissected ascending aorta and the false lumen of the descending aorta at the level of the diaphragm (FL-diaphragm level resulting in respective time-intensity curves. Results. For the FL-diaphragm level, time-to-peak intensity and full width at half maximum were significantly shorter in the expansion group compared to the stable group (p=0.027 and p=0.003, and upward and downward slopes of time-intensity curves were significantly steeper (p=0.015 and p=0.005. The delay of peak intensity in the FL-diaphragm level compared to the nondissected ascending aorta was significantly shorter in the expansion group compared to the stable group (p=0.01. Conclusions. 3D TR-MRA detects significant alterations of hemodynamics within the patent false lumen of chronic expanding aortic dissections compared to stable aortic dissections.

  8. Magnetic resonance angiography virtual endoscopy in the assessment of pulmonary veins before radiofrequency ablation procedures for atrial fibrillation

    International Nuclear Information System (INIS)

    Cirillo, S.; Tosetti, Irene; Giuseppe, M.De; Longo, M.; Regge, D.; Bonamini, R.; Gaita, F.; Bianchi, F.; Vivalda, L.

    2004-01-01

    Magnetic resonance angiography (MRA) is a safe and non-invasive imaging method that can readily depict the pulmonary veins (PV), whose imaging has acquired momentum with the advent of new techniques for radiofrequency ablation of atrial fibrillation (AF). We evaluated whether virtual endoscopy from 3D MRA images (MRA-VE) is feasible in studying the morphology of PV. Fifty patients with AF underwent pre-ablative MRA (1.5 T). Images were acquired with axial T-2 weighted and 3D-SPGR sequences after intravenous administration of Gd-DTPA and automatic triggering. Postprocessing was performed by an experienced radiologist with maximum intensity projection (MIP) and virtual endoscopy software (Navigator, GEMS). The venoatrial junction was visualized with MRA-VE in 49 of 50 patients (98.0%). Twenty-seven patients (55.1%) had two ostia on both sides, 13 patients (26.5%) had two ostia on the right and a single common ostium on the left, 5 patients (10.2%) had accessory PV and 4 patients (8.2%) had both an accessory right PV and a single common ostium on the left. Flythrough navigation showed the number and spatial disposition of second-order PV branches in 48 out of 49 patients (98.0%). MRA-VE is an excellent tool for at-a-glance visualization of ostia morphology, navigation of second-generation PV branches and easy endoluminal assessment of left atrial structures in pre-ablative imaging. (orig.)

  9. Catheter Angiography

    Medline Plus

    Full Text Available ... medical conditions. Angiography uses one of three imaging technologies and, in most cases, a contrast material injection ... at these links. About Us | Contact Us | FAQ | Privacy | Terms of Use | Links | Site Map Copyright © 2018 ...

  10. Catheter Angiography

    Medline Plus

    Full Text Available ... you! Do you have a personal story about radiology? Share your patient story here Images × Image Gallery ... Contrast Materials CT Angiography (CTA) X-ray, Interventional Radiology and Nuclear Medicine Radiation Safety Images related to ...

  11. Sharing mutants and experimental information prepublication using FgMutantDb (https://scabusa.org/FgMutantDb).

    Science.gov (United States)

    Baldwin, Thomas T; Basenko, Evelina; Harb, Omar; Brown, Neil A; Urban, Martin; Hammond-Kosack, Kim E; Bregitzer, Phil P

    2018-06-01

    There is no comprehensive storage for generated mutants of Fusarium graminearum or data associated with these mutants. Instead, researchers relied on several independent and non-integrated databases. FgMutantDb was designed as a simple spreadsheet that is accessible globally on the web that will function as a centralized source of information on F. graminearum mutants. FgMutantDb aids in the maintenance and sharing of mutants within a research community. It will serve also as a platform for disseminating prepublication results as well as negative results that often go unreported. Additionally, the highly curated information on mutants in FgMutantDb will be shared with other databases (FungiDB, Ensembl, PhytoPath, and PHI-base) through updating reports. Here we describe the creation and potential usefulness of FgMutantDb to the F. graminearum research community, and provide a tutorial on its use. This type of database could be easily emulated for other fungal species. Published by Elsevier Inc.

  12. Advantages of time-resolved contrast-enhanced 4D MR angiography in splenic arterial steal syndrome.

    Science.gov (United States)

    Obmann, Verena C; Chalian, Majid; Mansoori, Bahar; Sanchez, Edmund; Gulani, Vikas

    2018-03-07

    Splenic artery steal syndrome (SASS) is a severe complication affecting up to 10% of orthotopic liver transplant (OLT) patients. In this case report, we present a 35-year-old male with OLT secondary to liver failure due to hemochromatosis, who developed SASS. We describe potential application of different imaging techniques for diagnosis of SASS with focus on the value of time-resolved contrast enhanced 4D magnetic resonance angiography (MRA). Copyright © 2018 Elsevier Inc. All rights reserved.

  13. Tangshen formula attenuates hepatic steatosis by inhibiting hepatic lipogenesis and augmenting fatty acid oxidation in db/db mice.

    Science.gov (United States)

    Kong, Qin; Zhang, Haojun; Zhao, Tingting; Zhang, Weiku; Yan, Meihua; Dong, Xi; Li, Ping

    2016-12-01

    Tangshen formula (TSF), a well-prescribed traditional Chinese formula, has been used in the treatment of diabetic nephropathy. However, whether TSF ameliorates dyslipidemia and liver injury associated with diabetes remains unclear. In this study, we examined the effects of TSF on lipid profiles and hepatic steatosis in db/db mice. For this purpose, 8‑week-old db/db mice were treated with TSF or saline for 12 weeks via gavage and db/m mice were used as controls. Body weight and blood glucose levels were monitored weekly and bi-weekly, respectively. Blood samples were obtained for the analysis of lipids and enzymes related to hepatic function, and liver tissues were analyzed by histology, immunohistochemistry and molecular examination. The results revealed that TSF markedly reduced body weight, liver index [liver/body weight (LW/BW)] and improved lipid profiles, hepatic function and steatosis in db/db mice. TSF induced the phosphoralation of AMP-activated protein kinase and inhibited the activity of sterol regulatory element-binding protein 1 together with the inhibition of the expression of genes involved in de novo lipogenesis (DNL) and gluconeogenesis, such as fatty acid synthase (FAS), acetyl-CoA carboxylase (ACC), stearoyl CoA desaturase 1 (SCD1), glucose-6-phosphatase (G6pc) and phosphoenolpyruvate carboxykinase 1 (Pck1). Additionally, the silent mating type information regulation 2 homolog 1 (Sirt1)/peroxisome proliferator-activated receptor α (PPARα)/malonyl-CoA decarboxylase (MLYCD) cascade was potently activated by TSF in the liver and skeletal muscle of db/db mice, which led to enhanced fatty acid oxidation. These findings demonstrated that TSF attenuated hepatic fat accumulation and steatosis in db/db mice by inhibiting lipogenesis and augmenting fatty acid oxidation.

  14. Improved cerebral energetics and ketone body metabolism in db/db mice

    DEFF Research Database (Denmark)

    Andersen, Jens V; Christensen, Sofie K; Nissen, Jakob D

    2017-01-01

    It is becoming evident that type 2 diabetes mellitus is affecting brain energy metabolism. The importance of alternative substrates for the brain in type 2 diabetes mellitus is poorly understood. The aim of this study was to investigate whether ketone bodies are relevant candidates to compensate...... metabolism in type 2 diabetes mellitus. The increased hippocampal ketone body utilization and improved mitochondrial function in db/db mice, may act as adaptive mechanisms in order to maintain cerebral energetics during hampered glucose metabolism....

  15. Comparison between digital subtraction angiography and magnetic resonance angiography in investigation of nonlacunar ischemic stroke in young patients: preliminary results Comparação entre arteriografia digital e angioressonância na investigação de acidente vascular cerebral isquêmico não-lacunar em pacientes jovens: resultados preliminares

    Directory of Open Access Journals (Sweden)

    Adriana Bastos Conforto

    2006-06-01

    Full Text Available PURPOSE: We preliminarily investigated the relevance of performing digital subtraction angiography (DSA in addition to magnetic resonance angiography (MRA in definition of ischemic stroke etiology in young patients. METHOD: DSAs and MRAs from 17 young patients with nonlacunar ischemic stroke were blindly analyzed and their impact on stroke management was evaluated. RESULTS: Etiologies were the same considering results of either DSA or MRA in 12/17 cases. In 15/17 patients no changes would have been made in treatment, regardless of the modality of angiography considered. CONCLUSION: These preliminary results suggest that DSA may be redundant in two thirds of ischemic strokes in young patients. Further larger prospective studies are necessary to determine indications of DSA in this age group.PROPÓSITO DO ESTUDO: Investigar de forma preliminar a relevância da realização de angiografia digital (AD adicionalmente a angioressonância (AR na definição de etiologias de acidente vascular cerebral isquêmico (AVCI em pacientes jovens. MÉTODO: ADs e ARs de 17 pacientes jovens com AVCIs não-lacunares foram analisadas. Avaliamos o impacto destes exames no manejo clínico dos casos. RESULTADOS: Em 12/17 casos, as etiologias dos AVCIs de acordo com os resultados de AD ou de AR foram idênticas. Em 15/17 pacientes, nenhuma mudança de conduta terapêutica seria realizada, independentemente da modalidade de exame considerada. CONCLUSÃO: Estes resultados preliminares sugerem que os resultados da AD podem ser redundantes em relação à AR em até dois terços dos pacientes jovens com AVCI. Estudos prospectivos maiores são necessários para otimizar o estabelecimento de indicações de AD nesta faixa etária.

  16. MongoDB the definitive guide

    CERN Document Server

    Chodorow, Kristina

    2010-01-01

    How does MongoDB help you manage a huMONGOus amount of data collected through your web application? With this authoritative introduction, you'll learn the many advantages of using document-oriented databases, and discover why MongoDB is a reliable, high-performance system that allows for almost infinite horizontal scalability. Written by engineers from 10gen, the company that develops and supports this open source database, MongoDB: The Definitive Guide provides guidance for database developers, advanced configuration for system administrators, and an overview of the concepts and use cases f

  17. Three-Dimensional Respiratory-Gated Coronary Mr Angiography with Reference to X-Ray Coronary Angiography

    International Nuclear Information System (INIS)

    Ikonen, A. E. J.; Manninen, H. I.; Vainio, P.; Vanninen, R. L.; Matsi, P. J.; Soimakallio, S.; Hirvonen, T.P.J.; Hartikainen, J.E.K.

    2003-01-01

    Purpose: To assess the clinical value of three-dimensional coronary MR angiography (CMRA) in the detection of significant coronary artery stenosis using conventional X-ray angiography as the standard reference. Material and Methods: Sixty-nine patients underwent X-ray coronary angiography and CMRA because of suspected or previously diagnosed coronary artery disease. MRI was performed with a 1.5-T whole body imaging system using ECG-triggered 3D gradient echo sequence with retrospective navigator echo respiratory gating and fat suppression. Results: A total of 276 coronary artery segments were analyzed. The X-ray coronary angiography was normal in 22 patients. Significant proximal stenoses (exceeding 50%) or occlusions were present in 102 coronary artery segments. In all, 120 stenoses or occlusions were identified in CMRA. Sixteen percent of the coronary artery segments had to be excluded because of poor image quality. The overall sensitivity and specificity for MRA for identification of significant stenosis were 75% and 62%, respectively. CMRA correctly detected 89% of patients with at least one vessel disease, but 6 patients with coronary artery disease would have been missed. Conclusions: Because of the high data exclusion and false-negative case rate, CMRA with retrospective navigator echo triggering is at present not suitable as a clinical screening method in coronary artery disease

  18. Catheter Angiography

    Medline Plus

    Full Text Available ... with you. top of page What are the benefits vs. risks? Benefits Angiography may eliminate the need for surgery. If ... cancer from excessive exposure to radiation. However, the benefit of an accurate diagnosis far outweighs the risk. ...

  19. The db/db mouse: a useful model for the study of diabetic retinal neurodegeneration.

    Directory of Open Access Journals (Sweden)

    Patricia Bogdanov

    Full Text Available BACKGROUND: To characterize the sequential events that are taking place in retinal neurodegeneration in a murine model of spontaneous type 2 diabetes (db/db mouse. METHODS: C57BLKsJ-db/db mice were used as spontaneous type 2 diabetic animal model, and C57BLKsJ-db/+ mice served as the control group. To assess the chronological sequence of the abnormalities the analysis was performed at different ages (8, 16 and 24 weeks. The retinas were evaluated in terms of morphological and functional abnormalities [electroretinography (ERG]. Histological markers of neurodegeneration (glial activation and apoptosis were evaluated by immunohistochemistry. In addition glutamate levels and glutamate/aspartate transporter (GLAST expression were assessed. Furthermore, to define gene expression changes associated with early diabetic retinopathy a transcriptome analyses was performed at 8 week. Furthermore, an additional interventional study to lower blood glucose levels was performed. RESULTS: Glial activation was higher in diabetic than in non diabetic mice in all the stages (p<0.01. In addition, a progressive loss of ganglion cells and a significant reduction of neuroretinal thickness were also observed in diabetic mice. All these histological hallmarks of neurodegeneration were less pronounced at week 8 than at week 16 and 24. Significant ERG abnormalities were present in diabetic mice at weeks 16 and 24 but not at week 8. Moreover, we observed a progressive accumulation of glutamate in diabetic mice associated with an early downregulation of GLAST. Morphological and ERG abnormalities were abrogated by lowering blood glucose levels. Finally, a dysregulation of several genes related to neurotransmission and oxidative stress such as UCP2 were found at week 8. CONCLUSIONS: Our results suggest that db/db mouse reproduce the features of the neurodegenerative process that occurs in the human diabetic eye. Therefore, it seems an appropriate model for investigating the

  20. Time-resolved magnetic resonance angiography (MRA) at 3.0 Tesla for evaluation of hemodynamic characteristics of vascular malformations: description of distinct subgroups.

    Science.gov (United States)

    Hammer, Simone; Uller, Wibke; Manger, Florentine; Fellner, Claudia; Zeman, Florian; Wohlgemuth, Walter A

    2017-01-01

    Quantitative evaluation of hemodynamic characteristics of arteriovenous and venous malformations using time-resolved magnetic resonance angiography (MRA) at 3.0 Tesla. Time-resolved MRA with interleaved stochastic trajectories (TWIST) at 3.0 Tesla was studied in 83 consecutive patients with venous malformations (VM) and arteriovenous malformations (AVM). Enhancement characteristics were calculated as percentage increase of signal intensity above baseline over time. Maximum percentage signal intensity increase (signal max ), time intervals between onset of arterial enhancement and lesion enhancement (t onset ), and time intervals between beginning of lesion enhancement and maximum percentage of lesion enhancement (t max ) were analyzed. All AVMs showed a high-flow hemodynamic pattern. Two significantly different (p 3.0 Tesla provides hemodynamic characterization of vascular malformations. VMs can be subclassified into two hemodynamic subgroups due to presence or absence of AVFs. • Time-resolved MRA at 3.0 Tesla provides quantitative hemodynamic characterization of vascular malformations. • Malformations significantly differ in time courses of enhancement and signal intensity increase. • AVMs show a distinctive high-flow hemodynamic pattern. • Two significantly different types of VMs emerged: VMs with and without AVFs.

  1. The potential for neurovascular intravenous angiography using K-edge digital subtraction angiography

    International Nuclear Information System (INIS)

    Schueltke, E.; Fiedler, S.; Kelly, M.; Griebel, R.; Juurlink, B.; LeDuc, G.; Esteve, F.; Le Bas, J.-F.; Renier, M.; Nemoz, C.; Meguro, K.

    2005-01-01

    Background: Catheterization of small-caliber blood vessels in the central nervous system can be extremely challenging. Alternatively, intravenous (i.v.) administration of contrast agent is minimally invasive and therefore carries a much lower risk for the patient. With conventional X-ray equipment, volumes of contrast agent that could be safely administered to the patient do not allow acquisition of high-quality images after i.v. injection, because the contrast bolus is extremely diluted by passage through the heart. However, synchrotron-based digital K-edge subtraction angiography does allow acquisition of high-quality images after i.v. administration of relatively small doses of contrast agent. Materials and methods: Eight adult male New Zealand rabbits were used for our experiments. Animals were submitted to both angiography with conventional X-ray equipment and synchrotron-based digital subtraction angiography. Results: With conventional X-ray equipment, no contrast was seen in either cerebral or spinal blood vessels after i.v. injection of iodinated contrast agent. However, using K-edge digital subtraction angiography, as little as 1 ml iodinated contrast agent, when administered as i.v. bolus, yielded images of small-caliber blood vessels in the central nervous system (both brain and spinal cord). Conclusions: If it would be possible to image blood vessels of the same diameter in the central nervous system of human patients, the synchrotron-based technique could yield high-quality images at a significantly lower risk for the patient than conventional X-ray imaging. Images could be acquired where catheterization of feeding blood vessels has proven impossible

  2. An aqueous extract of Portulaca oleracea ameliorates diabetic nephropathy through suppression of renal fibrosis and inflammation in diabetic db/db mice.

    Science.gov (United States)

    Lee, An Sook; Lee, Yun Jung; Lee, So Min; Yoon, Jung Joo; Kim, Jin Sook; Kang, Dae Gill; Lee, Ho Sub

    2012-01-01

    Diabetic nephropathy is one of the most common microvascular complications of diabetes and the leading cause of end-stage renal disease. In the present study, we investigated the renoprotective effect of the aqueous extract of Portulaca oleracea (AP) on diabetic nephropathy accelerated by renal fibrosis and inflammation in type 2 diabetic db/db mice. The mice were treated with AP (300 mg/kg/day, p.o.) for ten weeks to examine the long-term effects on diabetic nephropathy and renal dysfunction. We found that AP treatment markedly lowered blood glucose to 412 ± 11.4 mg/dl and plasma creatinine level to 2.3 ± 0.8 mg/dl compared to db/db mice (p < 0.05, p < 0.01, respectively). This study also showed that treatment with AP significantly decreased water intake and urine volume in diabetic db/db mice (p < 0.05). In immunohistological study, the renal expression of transforming growth factor-β1 (TGF-β1), advanced glycation end products (AGE), and intercellular adhesion molecule (ICAM)-1 markedly increased in the renal cortex of untreated db/db mice (p < 0.01). In contrast, AP treatment significantly reduced these expressions to 50 ± 2.1%, 48 ± 2.8%, 61 ± 1.1%, respectively (p < 0.01). Furthermore, NF-κB p65 activation in renal tissues markedly increased in untreated db/db mice, which was significantly suppressed by AP treatment. Taken together, these findings suggest that AP attenuates diabetic nephropathy through inhibition of renal fibrosis and inflammation in db/db mice.

  3. Spontaneous intracranial arterial dissection in the young: diagnosis by CT angiography

    Directory of Open Access Journals (Sweden)

    Given Curtis A

    2006-04-01

    Full Text Available Abstract Background Spontaneous carotid artery dissections have been rarely reported in children. Diagnosis has traditionally been confirmed by catheter arteriography. More recently diagnosis has been made by magnetic resonance imaging and magnetic resonance angiography; however the sensitivity of these techniques has yet to be determined. The authors are unaware of reports of carotid dissection confirmed by dynamic computed tomography (computerized tomographic arteriography in the young. Case presentation We recently evaluated a fourteen year-old male following the development of transient neurologic symptoms. There was no antecedent illness or trauma. Dynamic computed tomography revealed an intracranial dissection involving the supraclinoid segment of the left internal carotid artery (confirmed by catheter arteriography. Studies for vasculitis, pro-thrombotic states, and defects of collagen were negative. Conclusion Spontaneous carotid artery dissection is a potential cause of transient neurological symptoms and ischemic stroke in the pediatric population. Dynamic computed tomography appears to be a reliable diagnostic tool which can lead to early diagnosis.

  4. On the system of cine-angiography

    International Nuclear Information System (INIS)

    Wakamatsu, Koji; Togi, Hideaki; Yokoyama, Hironori

    1979-01-01

    National Institute of Circulatory Disease Centre have four angiography apparatuses which deal with more than 80 cases of cerebral blood vessel and 100 cases of heart blood vessel each month. Most of the angiography is cine-photography. Five more angiography apparatuses are expected to be operated in operation and RI examination rooms in the future. The problems on cine-angiography system were discussed as follows: (1) The proper dose must be chosen in order to obtain good quality of cine-images. (2) The cine resolution depends much on dose. (3) The lower X-ray tube voltage can give better contrast. (4) Suitable capacity for an X-ray tube is over 60 kW at 2 sec rating. (5) Cine-autophotography requires rapid response and a circuit for lock. (6) Influence of side scattering can be solved by a blanking circuit in biplane cine-photography. (7) Self-developing is desirable to improve the quality of cine-images. (Kobatake, H.)

  5. Novel small-molecule AMPK activator orally exerts beneficial effects on diabetic db/db mice

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yuan-Yuan; Yu, Li-Fang; Zhang, Li-Na; Qiu, Bei-Ying; Su, Ming-Bo; Wu, Fang; Chen, Da-Kai; Pang, Tao; Gu, Min; Zhang, Wei; Ma, Wei-Ping; Jiang, Hao-Wen; Li, Jing-Ya, E-mail: jyli@mail.shcnc.ac.cn; Nan, Fa-Jun, E-mail: fjnan@mail.shcnc.ac.cn; Li, Jia, E-mail: jli@mail.shcnc.ac.cn

    2013-12-01

    AMP-activated protein kinase (AMPK), which is a pivotal guardian of whole-body energy metabolism, has become an attractive therapeutic target for metabolic syndrome. Previously, using a homogeneous scintillation proximity assay, we identified the small-molecule AMPK activator C24 from an optimization based on the original allosteric activator PT1. In this paper, the AMPK activation mechanism of C24 and its potential beneficial effects on glucose and lipid metabolism on db/db mice were investigated. C24 allosterically stimulated inactive AMPK α subunit truncations and activated AMPK heterotrimers by antagonizing autoinhibition. In primary hepatocytes, C24 increased the phosphorylation of AMPK downstream target acetyl-CoA carboxylase dose-dependently without changing intracellular AMP/ATP ratio, indicating its allosteric activation in cells. Through activating AMPK, C24 decreased glucose output by down-regulating mRNA levels of phosphoenolpyruvate carboxykinase (PEPCK) and glucose-6-phosphatase (G6Pase) in primary hepatocytes. C24 also decreased the triglyceride and cholesterol contents in HepG2 cells. Due to its improved bioavailability, chronic oral treatment with multiple doses of C24 significantly reduced blood glucose and lipid levels in plasma, and improved the glucose tolerance of diabetic db/db mice. The hepatic transcriptional levels of PEPCK and G6Pase were reduced. These results demonstrate that this orally effective activator of AMPK represents a novel approach to the treatment of metabolic syndrome. - Highlights: • C24 activates AMPK through antagonizing autoinhibition within α subunit. • C24 activates AMPK in hepatocytes and decreases glucose output via AMPK. • C24 exerts beneficial effects on diabetic db/db mice. • C24 represents a novel therapeutic for treatment of metabolic syndrome.

  6. Novel small-molecule AMPK activator orally exerts beneficial effects on diabetic db/db mice

    International Nuclear Information System (INIS)

    Li, Yuan-Yuan; Yu, Li-Fang; Zhang, Li-Na; Qiu, Bei-Ying; Su, Ming-Bo; Wu, Fang; Chen, Da-Kai; Pang, Tao; Gu, Min; Zhang, Wei; Ma, Wei-Ping; Jiang, Hao-Wen; Li, Jing-Ya; Nan, Fa-Jun; Li, Jia

    2013-01-01

    AMP-activated protein kinase (AMPK), which is a pivotal guardian of whole-body energy metabolism, has become an attractive therapeutic target for metabolic syndrome. Previously, using a homogeneous scintillation proximity assay, we identified the small-molecule AMPK activator C24 from an optimization based on the original allosteric activator PT1. In this paper, the AMPK activation mechanism of C24 and its potential beneficial effects on glucose and lipid metabolism on db/db mice were investigated. C24 allosterically stimulated inactive AMPK α subunit truncations and activated AMPK heterotrimers by antagonizing autoinhibition. In primary hepatocytes, C24 increased the phosphorylation of AMPK downstream target acetyl-CoA carboxylase dose-dependently without changing intracellular AMP/ATP ratio, indicating its allosteric activation in cells. Through activating AMPK, C24 decreased glucose output by down-regulating mRNA levels of phosphoenolpyruvate carboxykinase (PEPCK) and glucose-6-phosphatase (G6Pase) in primary hepatocytes. C24 also decreased the triglyceride and cholesterol contents in HepG2 cells. Due to its improved bioavailability, chronic oral treatment with multiple doses of C24 significantly reduced blood glucose and lipid levels in plasma, and improved the glucose tolerance of diabetic db/db mice. The hepatic transcriptional levels of PEPCK and G6Pase were reduced. These results demonstrate that this orally effective activator of AMPK represents a novel approach to the treatment of metabolic syndrome. - Highlights: • C24 activates AMPK through antagonizing autoinhibition within α subunit. • C24 activates AMPK in hepatocytes and decreases glucose output via AMPK. • C24 exerts beneficial effects on diabetic db/db mice. • C24 represents a novel therapeutic for treatment of metabolic syndrome

  7. dbSNP

    Data.gov (United States)

    U.S. Department of Health & Human Services — dbSNP is a database of single nucleotide polymorphisms (SNPs) and multiple small-scale variations that include insertions/deletions, microsatellites, and...

  8. Comparison of spiral CT angiography with conventional digital subtraction angiography in the evaluation of renal transplant donors: a pilot study

    International Nuclear Information System (INIS)

    Chu, C.; Young, N.; Lau, H.

    2001-01-01

    Conventional digital subtraction renal arteriography (IA-DSA) has been traditionally used as the preoperative imaging modality for assessment of renal vascular anatomy for renal transplant donors. This study evaluates the potential use of spiral CT angiography in replacing IA-DSA in the preoperative assessment of this group of patients. Seven patients underwent both spiral CT angiography and IA-DSA between October 1997 and April 1998. It is concluded that spiral CT angiography can demonstrate the number, length and location of renal arteries and it is suggested that spiral CT angiography can potentially replace IA-DSA in the preoperative assessment of renal donors. Copyright (2001) Blackwell Science Pty Ltd

  9. Magnetic resonance imaging of popliteal artery pathologies

    International Nuclear Information System (INIS)

    Holden, Andrew; Merrilees, Stephen; Mitchell, Nicola; Hill, Andrew

    2008-01-01

    This paper illustrates examples of popliteal artery pathologies imaged with contrast enhanced magnetic resonance angiography (CE-MRA) and magnetic resonance imaging (MRI) at a single tertiary referral centre. Popliteal artery pathologies were identified in 1710 patients referred over a 6-year period with symptoms suggesting lower limb arterial occlusive disease. Common pathologies such as atherosclerotic occlusive disease, thromboemboli and aneurysm disease are discussed as well as unusual pathologies such as cystic adventitial disease, mycotic aneurysm and arterial entrapment. The combination of CE-MRA and the excellent soft tissue resolution of MRI allow detailed evaluation of arterial and peri-arterial pathologies, and facilitate appropriate management decisions

  10. Magnetic resonance imaging of popliteal artery pathologies

    Energy Technology Data Exchange (ETDEWEB)

    Holden, Andrew [Department of Radiology, Auckland City Hospital, Park Road, Grafton, Auckland 9 (New Zealand)], E-mail: andrewh@adhb.govt.nz; Merrilees, Stephen [Department of Radiology, Auckland City Hospital, Park Road, Grafton, Auckland 9 (New Zealand)], E-mail: smerrilees@adhb.govt.nz; Mitchell, Nicola [Department of Radiology, Auckland City Hospital, Park Road, Grafton, Auckland 9 (New Zealand)], E-mail: nmit010@ec.auckland.ac.nz; Hill, Andrew [Department of Vascular Surgery, Auckland City Hospital, Park Road, Grafton, Auckland 9 (New Zealand)], E-mail: ahill@adhb.govt.nz

    2008-07-15

    This paper illustrates examples of popliteal artery pathologies imaged with contrast enhanced magnetic resonance angiography (CE-MRA) and magnetic resonance imaging (MRI) at a single tertiary referral centre. Popliteal artery pathologies were identified in 1710 patients referred over a 6-year period with symptoms suggesting lower limb arterial occlusive disease. Common pathologies such as atherosclerotic occlusive disease, thromboemboli and aneurysm disease are discussed as well as unusual pathologies such as cystic adventitial disease, mycotic aneurysm and arterial entrapment. The combination of CE-MRA and the excellent soft tissue resolution of MRI allow detailed evaluation of arterial and peri-arterial pathologies, and facilitate appropriate management decisions.

  11. Complications with Outpatient Angiography and Interventional Procedures

    International Nuclear Information System (INIS)

    Young, Noel; Chi, Ka-Kit; Ajaka, Joe; McKay, Lesa; O'Neill, Diane; Wong, Kai Ping

    2002-01-01

    Purpose: To prospectively identify the complications, and rates of complication, in outpatient angiography and interventional procedures. Methods: There were 1050 consecutive patients, 646 men and 404 women, aged 17-89 years, with a total of 1239 procedures studied in a 2-year period, 1997 to 1999. Results: There were 560 cases of aorto-femoral angiography,resulting in 124 complications (22%), with pain or hematoma in 110.There were 206 cases of neck and cerebral angiography, resulting in 51 complications (25%), with pain and hematoma in 34, transient ischemic attack in 2 and cerebrovascular accident in 1. There were 197 interfentional procedures, with 177 being balloon dilatations, resulting in 68 complications (35%), with 2 having hematomas and 1 having hematoma/abscess requiring active treatment. There were 276 cases having various 'other' procedures (e.g., renal angiography),resulting in 65 complications (24%), with pain and hematoma in 61. No procedure-related death occurred. Eighteen cases (1.5%) had significant complications, with contrast allergy in eight. Conclusion: Outpatient angiography and intervention are relatively safe, with low significant complication rates

  12. Evaluating the use and utility of noninvasive angiography in diagnosing traumatic blunt cerebrovascular injury.

    Science.gov (United States)

    Wang, Anthony C; Charters, Michael A; Thawani, Jayesh P; Than, Khoi D; Sullivan, Stephen E; Graziano, Gregory P

    2012-06-01

    Digital subtraction angiography (DSA) is the gold standard for radiographic diagnosis of blunt cerebrovascular injury (BCVI), but use of computed tomography angiography (CTA) and magnetic resonance angiography (MRA) has increased dramatically in BCVI screening. This study explores the utility, effectiveness, and cost of noninvasive CTA and MRA screening for BCVI. Medical records of 2,025 consecutive adults evaluated for acute blunt neck trauma and BCVI were reviewed retrospectively. The incidence of BCVI, level(s) of cervical injury, involvement of foramina transversaria and internal carotid canals, presence of bony dislocation or subluxation, and subsequent treatment received were assessed. Asymptomatic patients were analyzed based on fracture and injury patterns. The cost effectiveness of CTA compared with DSA and the effects of CTA sensitivity and screening yield were determined. Of reviewed patients, 196 received CTA or MRA. Thirty-eight patients (19.4%) were diagnosed with BCVI. Screening yield in patients symptomatic at presentation was 48.8%. Large-vessel internal carotid, vertebral, anterior spinal, and basilar artery occlusion were associated with a positive screen, as were concurrent stroke and spinal cord injury (p tool for BCVI screening. Symptomatic presentation was the best predictor of BCVI. Significant cost savings were realized using CTA rather than DSA, with similar effectiveness and patient outcomes. Diagnostic study, level III; economic analysis, level IV. Copyright © 2012 by Lippincott Williams & Wilkins

  13. Usefulness of MR angiography in patients with non-traumatic intracranial hemorrhagic diseases

    International Nuclear Information System (INIS)

    Chung, Hyun Ung; Seo, Jeong Jin; Kim, Yun Hyeon; Moon, Woong Jae; Kim, Jae Kyu; Kang, Heoung Keun

    1994-01-01

    We assessed the usefulness of magnetic resonance angiography(MRA) and its techniques for differential diagnosis of hemorrhagic causes in patients with non-traumatic intracranial hemorrhagic diseases. We retrospectively reviewed 74 patients with non-traumatic intracranial hemorrhagic diseases, which were confirmed by radiological examinations(36 cases) and operations(38 cases). We compared the usefulness of magnetic resonance imaging(MRI) alone from MRI with MRA in evaluation of hemorrhagic causes. MRA was obtained by Time-of-Flight(TOF) and Phase Contrast(PC) technique. We investigated the usefulness of TOF and PC technique. MRI with MRA for detection of hemorrhagic causes(89%, 66 cases) was better than MRI only (64%, 47 cases). PC was better than TOF for evaluation of arteriovenous malformation and aneurysm due to subtraction of background noise(hemorrhage). MRI with MRA is more useful than MRI alone for evaluation of non-traumatic intracranial hemorrhagic causes

  14. 2D time-of-flight MR angiography using concatenated saturation bands for determining direction of flow in the intracranial vessels

    International Nuclear Information System (INIS)

    Nesbit, G.M.; DeMarco, J.K.

    1997-01-01

    We prospectively studied 15 patients to assess 2D time-of-flight (TOF) magnetic resonance angiography (MRA) with concatenated saturation bands for determining the direction of intracranial blood flow. This MRA sequence was compared to T2-weighted spin-echo MRI, 3D-TOF MRA, and intra-arterial angiography (IAA) as regards demonstration of vessels and determination of the direction of flow in the circle of Willis and its branches. The 2D-TOF MRA sequence demonstrated flow in 98.5 % vessel segments identified on IAA, 3D-TOF demonstrating 92 % and spin-echo images 77 %. The direction of flow shown on the 2D-TOF sequence was correct in 94 % when compared to conventional angiography, the remaining six segments not demonstrating flow. In ten patients, the flow abnormalities demonstrated by this MRA technique provided clinical information similar to that of conventional angiography in nine, but it was incomplete in three, and misleading in one. Slow retrograde flow in ophthalmic artery collaterals and differentiation of arteries and veins presented some problems. 2D-TOF MRA with concatenated saturation bands provides flow direction information using widely available, easily applicable TOF techniques, and can be a useful adjunct to MRI and MRA if information on flow direction is needed. (orig.). With 5 figs., 3 tabs

  15. Preoperative cerebral aneurysm assessment by three-dimensional CT angiography. Feasibility of surgery without cerebral angiography

    International Nuclear Information System (INIS)

    Kashiwagi, Shiro; Yamashita, Katsuhiro; Kato, Shoichi; Ito, Haruhide; Kurokawa, Kensuke; Watanabe, Yutaka

    1999-01-01

    The purpose of this study is to assess the capability of three-dimensional CT angiography (3D-CTA) to replace conventional catheter angiography as a preoperative examination for unruptured intracranial aneurysms. A prospective study was designed to evaluate 18 patients with 20 unruptured intracranial aneurysms (13 middle cerebral artery aneurysms, 6 anterior communicating artery aneurysms, and 1 internal carotid posterior communicating artery aneurysm) who underwent surgery. There were 12 women and 6 men with the average age of 63 years old. All patients were initially diagnosed as having intracranial aneurysms by MR angiography, followed by 3D-CTA and conventional catheter angiography for confirmation. Three experienced neurosurgeons were in charge of the operations. One of the neurosurgeons (surgeon 1) was provided with only 3D-CTA as the preoperative radiological evaluation, while the others (surgeon 2 and 3) were given through assessments with MRA, 3D-CTA, and conventional angiography. Surgeon 1 carried out the operations under careful observation by the surgeons 2 and 3. Problems encountered by the surgeon 1 during surgery were recorded. Neck clipping in 19 aneurysms and dome wrapping in 1 were successfully accomplished. All patients were discharged without complication. Surgeries went smoothly in 16 aneurysms with 3D-CTA alone. Discrepancies between the 3D-CTA findings and microsurgical anatomy were noted in 4 aneurysms: the size of the neck was overestimated in 3 aneurysms, the relationships to parent arteries were obscure in 2 aneurysms, and a perforating artery problematic to neck clipping was missed in 1 aneurysms by 3D-CTA. The results of this study support the notion that 3D-CTA can replace conventional catheter angiography as preoperative examination in the majority of regular-sized anterior circulation aneurysms. Nevertheless, surgeons should recognize and be prepared for the fact that 3D-CTA can give false impression about the aneurysm neck and

  16. Travelling wave resonators fabricated with low-loss hydrogenated amorphous silicon

    Science.gov (United States)

    Lipka, Timo; Amthor, Julia; Trieu, Hoc Khiem; Müller, Jörg

    2013-05-01

    Low-loss hydrogenated amorphous silicon is employed for the fabrication of various planar integrated travelling wave resonators. Microring, racetrack, and disk resonators of different dimensions were fabricated with CMOS-compatible processes and systematically investigated. The key properties of notch filter ring resonators as extinction ratio, Q-factor, free spectral range, and the group refractive index were determined for resonators of varying radius, thereby achieving critically coupled photonic systems with high extinction ratios of about 20 dB for both polarizations. Racetrack resonators that are arranged in add/drop configuration and high quality factor microdisk resonators were optically characterized, with the microdisks exhibiting Q-factors of greater than 100000. Four-channel add/drop wavelength-division multiplexing filters that are based on cascaded racetrack resonators are studied. The design, the fabrication, and the optical characterization are presented.

  17. Miniaturized bandpass filter using a meandered stepped-impedance resonator with a meandered-line stub-load on a GaAs substrate.

    Science.gov (United States)

    Chuluunbaatar, Z; Wang, C; Kim, N Y

    2014-01-01

    This paper reports a compact bandpass filter with improved skirt selectivity using integrated passive device fabrication technology on a GaAs substrate. The structure of the filter consists of electromagnetically coupled meandered-line symmetric stepped-impedance resonators. The strength of the coupling between the resonators is enhanced by using a meandered-line stub-load inside the resonators to improve the selectivity and miniaturize the size of the filter. In addition, the center frequency of the filter can be flexibly controlled by varying degrees of the capacitive coupling between resonator and stub-load. To verify the proposed concept, a protocol bandpass filter with center frequency of 6.53 GHz was designed, fabricated, and measured, with a return loss and insertion loss of 39.1 dB and 1.63 dB.

  18. DPP-4 inhibitor des-F-sitagliptin treatment increased insulin exocytosis from db/db mice {beta} cells

    Energy Technology Data Exchange (ETDEWEB)

    Nagamatsu, Shinya, E-mail: shinya@ks.kyorin-u.ac.jp [Department of Biochemistry, Kyorin University School of Medicine, Mitaka, Tokyo 181-8611 (Japan); Ohara-Imaizumi, Mica; Nakamichi, Yoko; Aoyagi, Kyota; Nishiwaki, Chiyono [Department of Biochemistry, Kyorin University School of Medicine, Mitaka, Tokyo 181-8611 (Japan)

    2011-09-09

    Highlights: {yields} Anti-diabetic new drug, DPP-4 inhibitor, can affect the insulin exocytosis. {yields} DPP-4 inhibitor treatment altered syntaxin 1 expression. {yields} Treatment of db/db mice with DPP-4 inhibitor increased insulin release. -- Abstract: Incretin promotes insulin secretion acutely. Recently, orally-administered DPP-4 inhibitors represent a new class of anti-hyperglycemic agents. Indeed, inhibitors of dipeptidyl peptidase-IV (DPP-4), sitagliptin, has just begun to be widely used as therapeutics for type 2 diabetes. However, the effects of sitagliptin-treatment on insulin exocytosis from single {beta}-cells are yet unknown. We therefore investigated how sitagliptin-treatment in db/db mice affects insulin exocytosis by treating db/db mice with des-F-sitagliptin for 2 weeks. Perfusion studies showed that 2 weeks-sitagliptin treatment potentiated insulin secretion. We then analyzed insulin granule motion and SNARE protein, syntaxin 1, by TIRF imaging system. TIRF imaging of insulin exocytosis showed the increased number of docked insulin granules and increased fusion events from them during first-phase release. In accord with insulin exocytosis data, des-F-sitagliptin-treatment increased the number of syntaxin 1 clusters on the plasma membrane. Thus, our data demonstrated that 2-weeks des-F-sitagliptin-treatment increased the fusion events of insulin granules, probably via increased number of docked insulin granules and that of syntaxin 1 clusters.

  19. Catheter Angiography

    Medline Plus

    Full Text Available ... small burst of radiation that passes through the body, recording an image on photographic film or a special detector. Different ... about radiology? Share your patient story here Images × ... Related Articles and Media Angioplasty and Vascular Stenting MR Angiography (MRA) Contrast ...

  20. Stent sizing strategies in renal artery stenting: the comparison of conventional invasive renal angiography with renal computed tomographic angiography.

    Science.gov (United States)

    Kadziela, Jacek; Michalowska, Ilona; Pregowski, Jerzy; Janaszek-Sitkowska, Hanna; Lech, Katarzyna; Kabat, Marek; Staruch, Adam; Januszewicz, Andrzej; Witkowski, Adam

    2016-01-01

    Randomized trials comparing invasive treatment of renal artery stenosis with standard pharmacotherapy did not show substantial benefit from revascularization. One of the potential reasons for that may be suboptimal procedure technique. To compare renal stent sizing using two modalities: three-dimensional renal computed tomography angiography (CTA) versus conventional angiography. Forty patients (41 renal arteries), aged 65.1 ±8.5 years, who underwent renal artery stenting with preprocedural CTA performed within 6 months, were retrospectively analyzed. In CTA analysis, reference diameter (CTA-D) and lesion length (CTA_LL) were measured and proposed stent diameter and length were recorded. Similarly, angiographic reference diameter (ANGIO_D) and lesion length (ANGIO_LL) as well as proposed stent dimensions were obtained by visual estimation. The median CTA_D was 0.5 mm larger than the median ANGIO_D (p < 0.001). Also, the proposed stent diameter in CTA evaluation was 0.5 mm larger than that in angiography (p < 0.0001). The median CTA_LL was 1 mm longer than the ANGIO_LL (p = NS), with significant correlation of these variables (r = 0.66, p < 0.0001). The median proposed stent length with CTA was equal to that proposed with angiography. The median diameter of the implanted stent was 0.5 mm smaller than that proposed in CTA (p < 0.0005) and identical to that proposed in angiography. The median length of the actual stent was longer than that proposed in angiography (p = 0.0001). Renal CTA has potential advantages as a tool adjunctive to angiography in appropriate stent sizing. Careful evaluation of the available CTA scans may be beneficial and should be considered prior to the planned procedure.

  1. Tangshen Formula Attenuates Diabetic Nephropathy by Promoting ABCA1-Mediated Renal Cholesterol Efflux in db/db Mice.

    Science.gov (United States)

    Liu, Peng; Peng, Liang; Zhang, Haojun; Tang, Patrick Ming-Kuen; Zhao, Tingting; Yan, Meihua; Zhao, Hailing; Huang, Xiaoru; Lan, Huiyao; Li, Ping

    2018-01-01

    The commonly prescribed Tangshen Formula (TSF) is a traditional Chinese formulation that has been shown to reduce plasma lipid metabolism and proteinuria and improve the estimated glomerular filtration rate (eGFR) in patients with diabetic kidney disease. This study investigated the underlying mechanism whereby TSF regulates renal lipid accumulation and ameliorates diabetic renal injuries in spontaneous diabetic db/db mice and in vitro in sodium palmitate (PA)-stimulated and Abca1-SiRNA-transfected mouse tubular epithelial cells (mTECs). The results revealed that TSF treatment significantly ameliorated the renal injuries by lowering urinary albumin excretion and improving renal tissue injuries in diabetic (db/db) mice. Interestingly, the treatment with TSF also resulted in decreased cholesterol levels in the renal tissues of db/db mice, which was associated with increased expression of the peroxisome proliferator-activated receptor γ coactivator 1-α (PGC-1α), the Liver X receptors (LXR), and ATP-binding cassette subfamily A member 1 (ABCA1), suggesting that TSF might attenuate diabetic kidney injury via a mechanism associated with improving cholesterol efflux in the diabetic kidney. This was investigated in vitro in mTECs, and the results showed that TSF reduced the PA-stimulated cholesterol accumulation in mTECs. Mechanistically, the addition of TSF was capable of reversing PA-induced downregulation of PGC-1α, LXR, and ABCA1 expression and cholesterol accumulation in mTECs, suggesting that TSF might act the protection via the PGC-1α-LXR-ABCA1 pathway to improve the cholesterol efflux in the renal tissues of db/db mice. This was further confirmed by silencing ABCA1 to block the promotive effect of TSF on cholesterol efflux in vitro . In conclusion, TSF might ameliorate diabetic kidney injuries by promoting ABCA1-mediated renal cholesterol efflux.

  2. ToxRefDB - Release user-friendly web-based tool for mining ToxRefDB

    Science.gov (United States)

    The updated URL link is for a table of NCCT ToxCast public datasets. The next to last row of the table has the link for the US EPA ToxCast ToxRefDB Data Release October 2014. ToxRefDB provides detailed chemical toxicity data in a publically accessible searchable format. ToxRefD...

  3. Dicty_cDB: SLJ310 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available 5' similar to Arabidopsis thaliana sequence At1g48030 lipoamide dehydrogenase precursor see http://mips... At1g48030 lipoamide dehydrogenase precursor see http://mips.gsf.de/proj/thal/db/index.html, mRNA sequence.

  4. Synthesis, multi-nonlinear dielectric resonance and electromagnetic absorption properties of hcp-cobalt particles

    International Nuclear Information System (INIS)

    Wen, Shulai; Liu, Ying; Zhao, Xiuchen; Cheng, Jingwei; Li, Hong

    2014-01-01

    Hcp-cobalt particles were successfully prepared by a liquid phase reduction method, and the microstructure, static magnetic properties, electromagnetic and microwave absorption properties of the cobalt particles with irregular shape were investigated in detail. The measured results indicate that the saturation magnetization was less than that of hcp-Co single crystals, and the coercivity was larger than that of bulk cobalt crystal. The permittivity presents multi-nonlinear dielectric resonance, which may result from the irregular shape containing parts of cutting angle of dodecahedron of cobalt particles. The real part of permeability decreases with the frequency, and the imaginary part has a wide resonant peak. The paraffin-based composite containing 70 wt% cobalt particles possessed strong absorption characteristics with a minimum RL of −38.97 dB at 10.81 GHz and an absorption band with RL under −10 dB from 8.72 to 13.26 GHz when the thickness is 1.8 mm, which exhibits excellent microwave absorption in middle and high frequency. The architectural design of material morphologies is important for improving microwave absorption properties toward future application. - Highlights: • Hcp-cobalt particles were prepared by a liquid phase reduction method. • The saturation magnetization was less than that of hcp-Co single crystals. • The permittivity presents multi-nonlinear dielectric resonance. • The real part of permeability decreases with frequency, and the imaginary part presents a wide resonant peak. • The paraffin-based composite possessed a minimum RL of −38.97 dB at 10.81 GHz

  5. Catheter Angiography

    Medline Plus

    Full Text Available ... navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us ... the equipment look like? How does the procedure work? How is the ... and treat medical conditions. Angiography uses one of three imaging technologies and, ...

  6. A finite element solution to conjugated heat transfer in tissue using magnetic resonance angiography to measure the in vitro velocity field

    Science.gov (United States)

    Dutton, Andrew William

    1993-12-01

    A combined numerical and experimental system for tissue heat transfer analysis was developed. The goal was to develop an integrated set of tools for studying the problem of providing accurate temperature estimation for use in hyperthermia treatment planning in a clinical environment. The completed system combines (1) Magnetic Resonance Angiography (MRA) to non-destructively measure the velocity field in situ, (2) the Streamwise Upwind Petrov-Galerkin finite element solution to the 3D steady state convective energy equation (CEE), (3) a medical image based automatic 3D mesh generator, and (4) a Gaussian type estimator to determine unknown thermal model parameters such as thermal conductivity, blood perfusion, and blood velocities from measured temperature data. The system was capable of using any combination of three thermal models (1) the Convective Energy Equation (CEE), (2) the Bioheat Transfer Equation (BHTE), and (3) the Effective Thermal Conductivity Equation (ETCE) Incorporation of the theoretically correct CEE was a significant theoretical advance over approximate models made possible by the use of MRA to directly measure the 3D velocity field in situ. Experiments were carried out in a perfused alcohol fixed canine liver with hyperthermia induced through scanned focused ultrasound Velocity fields were measured using Phase Contrast Angiography. The complete system was then used to (1) develop a 3D finite element model based upon user traced outlines over a series of MR images of the liver and (2) simulate temperatures at steady state using the CEE, BHTE, and ETCE thermal models in conjunction with the gauss estimator. Results of using the system on an in vitro liver preparation indicate the need for improved accuracy in the MRA scans and accurate spatial registration between the thermocouple junctions, the measured velocity field, and the scanned ultrasound power No individual thermal model was able to meet the desired accuracy of 0.5 deg C, the resolution

  7. Ultralow loss, high Q, four port resonant couplers for quantum optics and photonics.

    Science.gov (United States)

    Rokhsari, H; Vahala, K J

    2004-06-25

    We demonstrate a low-loss, optical four port resonant coupler (add-drop geometry), using ultrahigh Q (>10(8)) toroidal microcavities. Different regimes of operation are investigated by variation of coupling between resonator and fiber taper waveguides. As a result, waveguide-to-waveguide power transfer efficiency of 93% (0.3 dB loss) and nonresonant insertion loss of 0.02% (photonic networks.

  8. Analysis of neuron–astrocyte metabolic cooperation in the brain of db/db mice with cognitive decline using 13C NMR spectroscopy

    Science.gov (United States)

    Zheng, Hong; Zheng, Yongquan; Wang, Dan; Cai, Aimin; Lin, Qiuting; Zhao, Liangcai; Chen, Minjiang; Deng, Mingjie; Ye, Xinjian

    2016-01-01

    Type 2 diabetes has been linked to cognitive impairment, but its potential metabolic mechanism is still unclear. The present study aimed to explore neuron–astrocyte metabolic cooperation in the brain of diabetic (db/db, BKS.Cg-m+/+ Leprdb/J) mice with cognitive decline using 13C NMR technique in combination with intravenous [2-13C]-acetate and [3-13C]-lactate infusions. We found that the 13C-enrichment from [2-13C]-acetate into tricarboxylic acid cycle intermediate, succinate, was significantly decreased in db/db mice with cognitive decline compared with wild-type (WT, C57BLKS/J) mice, while an opposite result was obtained after [3-13C]-lactate infusion. Relative to WT mice, db/db mice with cognitive decline had significantly lower 13C labeling percentages in neurotransmitters including glutamine, glutamate, and γ-aminobutyric acid after [2-13C]-acetate infusion. However, [3-13C]-lactate resulted in increased 13C-enrichments in neurotransmitters in db/db mice with cognitive decline. This may indicate that the disturbance of neurotransmitter metabolism occurred during the development of cognitive decline. In addition, a reduction in 13C-labeling of lactate and an increase in gluconeogenesis were found from both labeled infusions in db/db mice with cognitive decline. Therefore, our results suggest that the development of cognitive decline in type 2 diabetes may be implicated to an unbalanced metabolism in neuron–astrocyte cooperation and an enhancement of gluconeogenesis. PMID:26762505

  9. Analysis of neuron-astrocyte metabolic cooperation in the brain of db/db mice with cognitive decline using 13C NMR spectroscopy.

    Science.gov (United States)

    Zheng, Hong; Zheng, Yongquan; Wang, Dan; Cai, Aimin; Lin, Qiuting; Zhao, Liangcai; Chen, Minjiang; Deng, Mingjie; Ye, Xinjian; Gao, Hongchang

    2017-01-01

    Type 2 diabetes has been linked to cognitive impairment, but its potential metabolic mechanism is still unclear. The present study aimed to explore neuron-astrocyte metabolic cooperation in the brain of diabetic (db/db, BKS.Cg-m +/+ Leprdb/J) mice with cognitive decline using 13 C NMR technique in combination with intravenous [2- 13 C]-acetate and [3- 13 C]-lactate infusions. We found that the 13 C-enrichment from [2- 13 C]-acetate into tricarboxylic acid cycle intermediate, succinate, was significantly decreased in db/db mice with cognitive decline compared with wild-type (WT, C57BLKS/J) mice, while an opposite result was obtained after [3- 13 C]-lactate infusion. Relative to WT mice, db/db mice with cognitive decline had significantly lower 13 C labeling percentages in neurotransmitters including glutamine, glutamate, and γ-aminobutyric acid after [2- 13 C]-acetate infusion. However, [3- 13 C]-lactate resulted in increased 13 C-enrichments in neurotransmitters in db/db mice with cognitive decline. This may indicate that the disturbance of neurotransmitter metabolism occurred during the development of cognitive decline. In addition, a reduction in 13 C-labeling of lactate and an increase in gluconeogenesis were found from both labeled infusions in db/db mice with cognitive decline. Therefore, our results suggest that the development of cognitive decline in type 2 diabetes may be implicated to an unbalanced metabolism in neuron-astrocyte cooperation and an enhancement of gluconeogenesis. © The Author(s) 2016.

  10. Getting started with LevelDB

    CERN Document Server

    Dent, Andy

    2013-01-01

    The book is a concise guide for using LevelDB. It explains database concepts and the use of C++, ranging from the basics all the way to high level topics in an easy to follow, step-by-step format.The book is meant for developers who want an embedded database for their applications. Experienced programmers can pick up on the sophisticated data mapping patterns and tuning tips.Getting Started with LevelDB requires a minimal background in programming in C++ or Objective-C for OS/X or iOS and familiarity with XCode. Therefore it teaches enough C++ to use LevelDB without presuming any C++ knowledge

  11. The study of vascular dynamics for the effect of a compress pack on pain relief using magnetic resonance angiography

    International Nuclear Information System (INIS)

    Baek, Ji Won; Lim, Young Khi

    2015-01-01

    This study was to investigate the effects of the hot compress pack on alleviating local muscular discomfort, stiffness in limbs as well as the chronic pains such as migraine in terms of hemodynamics. In this study, the hot compress band was put on the neck and the local physiological change on the stimulation site and the cranial blood circulation change were examined. We recruited healthy volunteers (n=8, mean age: 32.13 (4.61)), who participated in the magnetic resonance imaging (MRI) study. Local skin color and temperature were measured for the local effect of the hot compress band and the changes of intra-cranial and extra-cranial blood vessels were examined with MR angiography (MRA) images. The skin temperature increased from 36.4 degrees Celsius at the rest condition to 36.7 degrees Celsius and 37.1 degrees Celsius after 15 min and 30 min stimulation, respectively. The change of the extra-cranial blood vessels between pre-stimulation and post-stimulation of 30 min was significantly increased (+38.8%), while the change of the intra-cranial blood vessels was negligible. In this study, we demonstrated that the hot compress band on the neck yielded the increase of local skin temperature on the stimulation site and it made an effect on the extracranial circulation. In conclusion, the stimulation with a hot compress could facilitate the blood circulation, causing to relieve the muscular discomfort, stiffness in limbs as well as the chronic pains such as migraine

  12. The study of vascular dynamics for the effect of a compress pack on pain relief using magnetic resonance angiography

    Energy Technology Data Exchange (ETDEWEB)

    Baek, Ji Won; Lim, Young Khi [Gachon University, Sungnam (Korea, Republic of)

    2015-12-15

    This study was to investigate the effects of the hot compress pack on alleviating local muscular discomfort, stiffness in limbs as well as the chronic pains such as migraine in terms of hemodynamics. In this study, the hot compress band was put on the neck and the local physiological change on the stimulation site and the cranial blood circulation change were examined. We recruited healthy volunteers (n=8, mean age: 32.13 (4.61)), who participated in the magnetic resonance imaging (MRI) study. Local skin color and temperature were measured for the local effect of the hot compress band and the changes of intra-cranial and extra-cranial blood vessels were examined with MR angiography (MRA) images. The skin temperature increased from 36.4 degrees Celsius at the rest condition to 36.7 degrees Celsius and 37.1 degrees Celsius after 15 min and 30 min stimulation, respectively. The change of the extra-cranial blood vessels between pre-stimulation and post-stimulation of 30 min was significantly increased (+38.8%), while the change of the intra-cranial blood vessels was negligible. In this study, we demonstrated that the hot compress band on the neck yielded the increase of local skin temperature on the stimulation site and it made an effect on the extracranial circulation. In conclusion, the stimulation with a hot compress could facilitate the blood circulation, causing to relieve the muscular discomfort, stiffness in limbs as well as the chronic pains such as migraine.

  13. dbVar

    Data.gov (United States)

    U.S. Department of Health & Human Services — dbVar is a database of genomic structural variation. It accepts data from all species and includes clinical data. It can accept diverse types of events, including...

  14. A resonant beam detector for TEVATRON tune monitoring

    International Nuclear Information System (INIS)

    Martin, D.; Fellenz, B.; Hood, C.; Johnson, M.; Shafer, R.; Siemann, R.; Zurawski, J.

    1989-03-01

    An inductively resonated, balanced stripline pickup has been constructed for observing tune spectra. The device is a sensitive betatron oscillation and Schottky noise pickup, providing 25 dB gain over untuned detectors of like geometry. The electrodes are motorized so the device center and aperture may be remotely adjusted. To tune the resonator onto the 21.4 MHz operating frequency, a motorized capacitor is employed. Quadrature signals from a pair of detectors has enabled observation of individual p and p coherent motions to nanometer levels. 8 refs., 5 figs

  15. Giant magnetic modulation of a planar, hybrid metamolecule resonance

    International Nuclear Information System (INIS)

    Gregory, Simon A; Stenning, Gavin B G; Bowden, Graham J; De Groot, Peter A J; Zheludev, Nikolay I

    2014-01-01

    Coupling magnetic elements to metamaterial structures creates hybrid metamolecules with new opportunities. Here we report on the magnetic control of a metamolecule resonance, by utilizing the interaction between a single split ring resonator (SRR) and a magnetic thin film of permalloy. To suppress eddy current shielding, the permalloy films are patterned into arrays of 30–500 μm diameter discs. Strong hybridized resonances were observed at the anticrossing between the split ring resonance and the ferromagnetic resonance (FMR) of the permalloy. In particular, it is possible to achieve 40 dB modulation of the electric (symmetric) mode of the SRR on sweeping the applied magnetic field through the SRR/FMR anticrossing. The results open the way to the design of planar metamaterials, with potential applications in nonlinear metamaterials, tunable metamaterials and spintronics. (papers)

  16. Flow cytometry analysis reveals different activation profiles of thrombin- or TRAP-stimulated platelets in db/db mice. The regulatory role of PAR-3.

    Science.gov (United States)

    Kassassir, Hassan; Siewiera, Karolina; Talar, Marcin; Przygodzki, Tomasz; Watala, Cezary

    2017-06-01

    Recent studies have shown that it may be the concentration of thrombin, which is discriminative in determining of the mechanism of platelet activation via protease activated receptors (PARs). Whether the observed phenomenon of differentiated responses of mouse platelets to various thrombin concentrations in non-diabetic db/+ and diabetic db/db mice depends upon the concerted action of various PARs, remains to be established. We found elevated reactivity of platelets, as well as the enhanced PAR-3 expression in response to both the used concentrations of AYPGKF in db/db mice, as compared to db/+ heterozygotes. At low concentration of thrombin platelets from diabetic mice demonstrated hyperreactivity, reflected by higher expression of PAR-3. For higher thrombin concentration, blood platelets from db/db mice appeared hyporeactive, compared to db/+ animals, while no significant differences in PAR-3 expression were observed between diabetic and non-diabetic mice. The novel and previously unreported finding resulting from our study is that the increased expression of PAR-3 in response to either TRAP for PAR-4 or low thrombin (when PAR-4 is not the efficient thrombin receptor) may be one of the key events contributing to higher reactivity of platelets in db/db mice. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Prevalence Study of Proximal Vertebral Artery Stenosis Using High-Resolution Contrast-Enhanced Magnetic Resonance Angiography

    International Nuclear Information System (INIS)

    Kim, S.H.; Lee, J.S.; Kwon, O.K.; Han, M.K.; Kim, J.H.

    2005-01-01

    Purpose: To evaluate the prevalence of proximal vertebral artery stenosis, compared with those of the distal vertebral/basilar artery and extracranial internal carotid artery, in a large population of stroke and non-stroke patients. Material and Methods: Nine-hundred-and-thirty-five patients who underwent high-resolution contrast-enhanced magnetic resonance angiography in a regional general hospital were categorized into six groups based on neurological symptoms and disease: an asymptomatic group (n ∼ 182), a minor symptom group with headache or dizziness (n ∼ 519), a cardiac group with coronary artery steno-occlusive disease (n ∼ 15), a hemorrhagic group with old cerebral hemorrhage (n ∼ 26), an anterior circulation infarct group (n ∼ 121), and posterior circulation infarct group (n ∼ 72). Prevalence of stenosis of the proximal vertebral artery, distal vertebral/basilar artery, and internal carotid artery was analyzed. Results: The prevalence of stenosis of the proximal vertebral artery, distal vertebral/basilar artery, and internal carotid artery was 12.9%, 5.5%, and 7.2%, respectively, in the study population, and rose as the age increased (P <0.0001 for all arteries). The prevalence of stenosis of the proximal vertebral artery, distal vertebral/basilar artery, and internal carotid artery was 3.3%, 0.5%, and.1%, respectively, in the asymptomatic group; 8.3%, 2.1%, and 3.7%, respectively, in the minor symptom group; 13.3%, 6.7%, and 6.7%, respectively, in the cardiac group; 19.2%, 7.7%, and 7.7%, respectively, in the hemorrhagic group; 27.3%, 8.3%, and 25.6%, respectively, in the anterior circulation infarct group; and 44.4%, 36.1%, and 16.7%, respectively, in the posterior circulation infarct group. This increasing tendency of stenosis accordingly was statistically significant ( P <0.0001 for all arteries). Conclusion: The prevalence of proximal vertebral artery stenosis was highest, compared with those of the distal vertebral/basilar artery and

  18. Retrograde flow in the dural sinuses detected by three-dimensional time-of-flight MR angiography

    International Nuclear Information System (INIS)

    Uchino, Akira; Nomiyama, Keita; Takase, Yukinori; Nakazono, Takahiko; Tominaga, Yukiko; Imaizumi, Takeshi; Kudo, Sho

    2007-01-01

    Retrograde flow in the left dural sinuses is sometimes detected by three-dimensional time-of-flight (3D-TOF) magnetic resonance (MR) angiography. The purpose of this study was to evaluate the incidence of this phenomenon and its characteristic features on 3D-TOF MR angiograms. We retrospectively reviewed cranial MR angiography images of 1,078 patients examined at our institution. All images were obtained by the 3D-TOF technique with one of two 1.5-T scanners. Maximum intensity projection (MIP) images in the horizontal rotation view were displayed stereoscopically. We reviewed the source images, inferosuperior MIP images, and horizontal MIP images and identified retrograde flow in the dural sinuses. We found retrograde flow in the dural sinuses of 67 patients on the source images from 3D-TOF MR angiography; the incidence was 6.2%. In 47 of the 67 patients, retrograde flow was identified in the left inferior petrosal sinus, in 13, it was seen in the left sigmoid sinus, and in 6, it was seen in the left inferior petrosal and left sigmoid sinuses. The remaining patient had retrograde flow in the left inferior petrosal and left and right sigmoid sinuses. The mean age of the patients with retrograde flow was slightly greater than that of the patients without this phenomenon (70 years vs 63 years). Retrograde flow in the dural sinuses frequently occurs on the left side in middle-aged and elderly patients during 3D-TOF MR angiography performed with the patient in the supine position. This phenomenon should not be misdiagnosed as a dural arteriovenous fistula. (orig.)

  19. New method of digital angiography

    International Nuclear Information System (INIS)

    Hashiya, Junichi; Korenaga, Takeo; Sakurai, Kenji; Sakai, Fumikazu; Kato, Hisatoyo; Takano, Masao.

    1982-01-01

    New experience of digital angiography using Fuji Intelligent Diagnostic X-ray System was reported. The system utilizes newly developed high sensitivity imaging plate in conjunction with computerized image processor instead of image intensifier-TV series, thus drastically improving image quality. Initial clinical trial was made in 46 cases including intravenous digital subtraction angiography and transcatheter digital arteriography. The advantages of this method were summerized as: 1. better resolution, 2. wider field size, 3. more sophisticated image manipulation program. (author)

  20. The pattern of renal vessels in live related potential donors pool. A multislice computed tomography angiography review

    International Nuclear Information System (INIS)

    Mishra, A.; Ehtuish, Ehtuish F.

    2006-01-01

    To assess the renal vessel anatomy, compare the findings with the perioperative findings, to determine the sensitivity of multislice computed tomography (CT) angiography in the work-up of live potential donors and to discuss and compare the results of the present study with the reported results using single slice CT, magnetic resonance (MRI) and conventional angiography (CA).Retrospective analysis of the angiographic data of 118 of prospective live related kidney donors was carried out from October 2004 to August 2005 at the National Organ Transplant Centre, Tripoli Central Hospital, Libya. All donors underwent renal angiography on multislice (16-slice) CT scan using 80 cc intravenous contrast with 1.25 mm slice thickness followed by maximum intensity projection (MIP) and volume rendering techniques (VRT) post-processing algorithms. The number of vessels, vessel bifurcation, vessel morphology and venous anatomy were analyzed and the findings were compared with the surgical findings. Multislice spiral CT angiography (MSCTA) showed clear delineation of the main renal arteries in all donors with detailed vessel morphology. The study revealed 100% sensitivity in detection of accessory renal vessels, with an overall incidence of 26.7%, which is the most common distribution in the parahilar region. The present study showed 100% sensitivity in the visualization and detection of main and accessory renal vessels. These results were comparable with conventional angiography which has so far been considered as the gold standard and were found superior in specificity and accuracy to the use of single slice CT (SSCT) and MR in the angiographic work-up of live renal donors. Due to improved detection of accessory vessels less than 2 mm in diameter, a higher incidence of aberrant vessels was seen on the right side as has been suggested so far. (author)

  1. Contrast-enhanced magnetic resonance angiography for the detection of crossing renal vessels in children with symptomatic ureteropelvic junction obstruction: comparison with operative findings

    Energy Technology Data Exchange (ETDEWEB)

    Calder, Alistair D.; Hiorns, Melanie P.; Olsen, Oystein E. [Hospital for Children NHS Trust, Department of Radiology, London (United Kingdom); Abhyankar, Aruna; Mushtaq, Imran [Hospital for Children NHS Trust, Department of Urology, London (United Kingdom)

    2007-04-15

    Crossing renal vessels (CRV) are associated with ureteropelvic junction (UPJ) obstruction, particularly when presentation is beyond the neonatal period. Their presence may influence surgical management. To evaluate the accuracy of contrast-enhanced magnetic resonance angiography (CE-MRA) in the identification of CRV in children requiring surgical treatment of symptomatic UPJ obstruction, against a gold standard of laparoscopic or open surgical findings. We reviewed CE-MRA studies (3-D T2-weighted turbo spin-echo and multiphase 3-D spoiled gradient echo following intravenous gadolinium administration) of 14 children, age range 6-15 years, performed prior to surgery for suspected CRV-related UPJ obstruction. Consensus reviews of the CE-MRA studies were compared with surgical findings. CE-MRA demonstrated CRV at the level of the obstruction in nine and no crossing vessels in five children. These were all verified intraoperatively ({chi}{sup 2} = 14.0; P < 0.001). In eight of the nine patients with CRV there was no evidence of intrinsic obstruction at surgery. In the remaining patient there was fibrosis of the upper ureter. CE-MRA is an accurate means of identifying CRV in children older than 6 years with symptomatic UPJ obstruction. (orig.)

  2. Contrast-enhanced magnetic resonance angiography for the detection of crossing renal vessels in children with symptomatic ureteropelvic junction obstruction: comparison with operative findings

    International Nuclear Information System (INIS)

    Calder, Alistair D.; Hiorns, Melanie P.; Olsen, Oystein E.; Abhyankar, Aruna; Mushtaq, Imran

    2007-01-01

    Crossing renal vessels (CRV) are associated with ureteropelvic junction (UPJ) obstruction, particularly when presentation is beyond the neonatal period. Their presence may influence surgical management. To evaluate the accuracy of contrast-enhanced magnetic resonance angiography (CE-MRA) in the identification of CRV in children requiring surgical treatment of symptomatic UPJ obstruction, against a gold standard of laparoscopic or open surgical findings. We reviewed CE-MRA studies (3-D T2-weighted turbo spin-echo and multiphase 3-D spoiled gradient echo following intravenous gadolinium administration) of 14 children, age range 6-15 years, performed prior to surgery for suspected CRV-related UPJ obstruction. Consensus reviews of the CE-MRA studies were compared with surgical findings. CE-MRA demonstrated CRV at the level of the obstruction in nine and no crossing vessels in five children. These were all verified intraoperatively (χ 2 = 14.0; P < 0.001). In eight of the nine patients with CRV there was no evidence of intrinsic obstruction at surgery. In the remaining patient there was fibrosis of the upper ureter. CE-MRA is an accurate means of identifying CRV in children older than 6 years with symptomatic UPJ obstruction. (orig.)

  3. CT Angiography in the Diagnosis of Brain Death

    International Nuclear Information System (INIS)

    Sawicki, Marcin; Bohatyrewicz, Romuald; Walecka, Anna; Sołek-Pastuszka, Joanna; Rowiński, Olgierd; Walecki, Jerzy

    2014-01-01

    Summary Brain death is defined as the irreversible cessation of functioning of the entire brain, including the brainstem. Brain death is principally established using clinical criteria including coma, absence of brainstem reflexes and loss of central drive to breathe assessed with apnea test. In situations in which clinical testing cannot be performed or when uncertainty exists about the reliability of its parts due to confounding conditions ancillary tests (i.a. imaging studies) may be useful. The objective of ancillary tests in the diagnosis of brain death is to demonstrate the absence of cerebral electrical activity (EEG and evoked potentials) or cerebral circulatory arrest. In clinical practice catheter cerebral angiography, perfusion scintigraphy, transcranial Doppler sonography, CT angiography and MR angiography are used. Other methods, like perfusion CT, xenon CT, MR spectroscopy, diffusion weighted MRI and functional MRI are being studied as potentially useful in the diagnosis of brain death. CT angiography has recently attracted attention as a promising alternative to catheter angiography – a reference test in the diagnosis of brain death. Since 1998 several major studies were published and national guidelines were introduced in several countries (e.g. in France, Austria, Switzerland, the Netherlands and Canada). This paper reviews technique, characteristic findings and criteria for the diagnosis of cerebral circulatory arrest in CT angiography

  4. Head and Neck Veins of the Mouse. A Magnetic Resonance, Micro Computed Tomography and High Frequency Color Doppler Ultrasound Study.

    Directory of Open Access Journals (Sweden)

    Marcello Mancini

    Full Text Available To characterize the anatomy of the venous outflow of the mouse brain using different imaging techniques. Ten C57/black male mice (age range: 7-8 weeks were imaged with high-frequency Ultrasound, Magnetic Resonance Angiography and ex-vivo Microcomputed tomography of the head and neck. Under general anesthesia, Ultrasound of neck veins was performed with a 20 MHz transducer; head and neck Magnetic Resonance Angiography data were collected on 9.4 T or 7 T scanners, and ex-vivo Microcomputed tomography angiography was obtained by filling the vessels with a radiopaque inert silicone rubber compound. All procedures were approved by the local ethical committee. The dorsal intracranial venous system is quite similar in mice and humans. Instead, the mouse Internal Jugular Veins are tiny vessels receiving the sigmoid sinuses and tributaries from cerebellum, occipital lobe and midbrain, while the majority of the cerebral blood, i.e. from the olfactory bulbs and fronto-parietal lobes, is apparently drained through skull base connections into the External Jugular Vein. Three main intra-extracranial anastomoses, absent in humans, are: 1 the petrosquamous sinus, draining into the posterior facial vein, 2 the veins of the olfactory bulb, draining into the superficial temporal vein through a foramen of the frontal bone 3 the cavernous sinus, draining in the External Jugular Vein through a foramen of the sphenoid bone. The anatomical structure of the mouse cranial venous outflow as depicted by Ultrasound, Microcomputed tomography and Magnetic Resonance Angiography is different from humans, with multiple connections between intra- and extra-cranial veins.

  5. Night-time restricted feeding normalises clock genes and Pai-1 gene expression in the db/db mouse liver.

    Science.gov (United States)

    Kudo, T; Akiyama, M; Kuriyama, K; Sudo, M; Moriya, T; Shibata, S

    2004-08-01

    An increase in PAI-1 activity is thought to be a key factor underlying myocardial infarction. Mouse Pai-1 (mPai-1) activity shows a daily rhythm in vivo, and its transcription seems to be controlled not only by clock genes but also by humoral factors such as insulin and triglycerides. Thus, we investigated daily clock genes and mPai-1 mRNA expression in the liver of db/db mice exhibiting high levels of glucose, insulin and triglycerides. Locomotor activity was measured using an infrared detection system. RT-PCR or in situ hybridisation methods were applied to measure gene expression. Humoral factors were measured using measurement kits. The db/ db mice showed attenuated locomotor activity rhythms. The rhythmic expression of mPer2 mRNA was severely diminished and the phase of mBmal1 oscillation was advanced in the db/db mouse liver, whereas mPai-1 mRNA was highly and constitutively expressed. Night-time restricted feeding led to a recovery not only from the diminished locomotor activity, but also from the diminished Per2 and advanced mBmal1 mRNA rhythms. Expression of mPai-1 mRNA in db/db mice was reduced to levels far below normal. Pioglitazone treatment slightly normalised glucose and insulin levels, with a slight reduction in mPai-1 gene expression. We demonstrated that Type 2 diabetes impairs the oscillation of the peripheral oscillator. Night-time restricted feeding rather than pioglitazone injection led to a recovery from the diminished locomotor activity, and altered oscillation of the peripheral clock and mPai-1 mRNA rhythm. Thus, we conclude that scheduled restricted food intake may be a useful form of treatment for diabetes.

  6. MR angiography of the iliofemoral artery system

    International Nuclear Information System (INIS)

    Steffens, J.C.; Link, J.; Brinkmann, G.; Reuter, M.; Heller, M.

    1997-01-01

    During the last years, magnetic resonance angiography (MRA) has become a widely used modality for intracerebral and carotid artery imaging. Due to technical limitations, the clinical impact of MRA in the iliofemoral arteries has been rather poor. New developments in MRA like ECG-triggered sequences and the occurrence of contrast-enhanced MRA has overcome most of these limitations. Therefore, a major advance in clinical use of these diagnostic tools can be predicted. This paper discussed the advantages of ECG-gated 2D-Phase contrast, ECG-gated 2D-Time-of-Flight and contrast enhanced FLASH 3D angiography sequences from a clinical point of view. 2D-PC-MRA is a robust technique, which provides an overview of the iliofemoral artery system in less than 5 minutes. Limitations are the true 2D impression of the sequence and the partial venous overlay. 2D-TOF-MRA on the other hand is time consuming, however it enables 3D reconstruction and effective venous suppression can be applied. Contrast enhanced MRA as the third sequence discussed provides high resolution images in less than 30 sec. However contrast bolus timing might be a problem. In conclusion the authors suggest a combination of 2D-PC-MRA and additional 2D-TOF sequences at questionable vacular areas as the modality of choice, due to the fact, that MRA of the iliofemoral arteries is mostly only one step of a complete lower limb examination. Contrast MRA might become the method of choice in the future however problems with multiple contrast injections and upper limits of contrast dose have to be solved. (orig.) [de

  7. GC/TOFMS analysis of metabolites in serum and urine reveals metabolic perturbation of TCA cycle in db/db mice involved in diabetic nephropathy.

    Science.gov (United States)

    Li, Mengjie; Wang, Xufang; Aa, Jiye; Qin, Weisong; Zha, Weibin; Ge, Yongchun; Liu, Linsheng; Zheng, Tian; Cao, Bei; Shi, Jian; Zhao, Chunyan; Wang, Xinwen; Yu, Xiaoyi; Wang, Guangji; Liu, Zhihong

    2013-06-01

    Early diagnosis of diabetic nephropathy (DN) is difficult although it is of crucial importance to prevent its development. To probe potential markers and the underlying mechanism of DN, an animal model of DN, the db/db mice, was used and serum and urine metabolites were profiled using gas chromatography/time-of-flight mass spectrometry. Metabolic patterns were evaluated based on serum and urine data. Principal component analysis of the data revealed an obvious metabonomic difference between db/db mice and controls, and db/db mice showed distinctly different metabolic patterns during the progression from diabetes to early, medium, and later DN. The identified metabolites discriminating between db/db mice and controls suggested that db/db mice have perturbations in the tricarboxylic acid cycle (TCA, citrate, malate, succinate, and aconitate), lipid metabolism, glycolysis, and amino acid turnover. The db/db mice were characterized by acidic urine, high TCA intermediates in serum at week 6 and a sharp decline thereafter, and gradual elevation of free fatty acids in the serum. The sharp drop of serum TCA intermediates from week 6 to 8 indicated the downregulated glycolysis and insulin resistance. However, urinary TCA intermediates did not decrease in parallel with those in the serum from week 6 to 10, and an increased portion of TCA intermediates in the serum was excreted into the urine at 8, 10, and 12 wk than at 6 wk, indicating kidney dysfunction occurred. The relative abundances of TCA intermediates in urine relative to those in serum were suggested as an index of renal damage.

  8. Getting started with OrientDB

    CERN Document Server

    Tesoriero, Claudio

    2013-01-01

    A standard tutorial aimed at making you an OrientDB expert, through the use of practical examples, explained in a step-by-step format.Getting Started with OrientDB 1.3.0 is great for database designers, developers, and systems engineers. It is assumed that you are familiar with NoSQL concepts, Java, and networking principles.

  9. Digital subtraction angiography (DSA)

    International Nuclear Information System (INIS)

    Ludwig, J.W.; Eikelboom, B.C.; Van Schaik, C.C.; Taams, A.J.; Teeuwen, C.

    1985-01-01

    Besides the non-invasive techniques, angiography remains essential. The disadvantages of angiography are the complexity of the procedure and the possibility of complications. Digital subtraction angiography (DSA) is a considerable improvement in the examination of vessels. In DSA, subtraction combined with enhancement of the signals allows the use of intravenous injection to obtain good images of the arteries. However, when the contrast material is supplied intravenously, a rather large amount of contrast material is necessary to obtain images of good quality. Quantities of 30-40 cc of contrast material are required. The advantage of the intravenous injection of contrast material rather than the use of a catheter to deliver the contrast material in loco is that it is almost non-invasive thus circumventing the complications caused by catheter manipulation in the arterial system. This makes it possible to apply this method on an out-patient basis. DSA can also be applied with intra-arterial selective injection of the contrast material. In this case, the strong enhancement with DSA allows the use of a small quantity of contrast material while still obtaining images of the vessels with good contrast definition

  10. Wide-range tuning of polymer microring resonators by the photobleaching of CLD-1 chromophores

    Science.gov (United States)

    Poon, Joyce K. S.; Huang, Yanyi; Paloczi, George T.; Yariv, Amnon; Zhang, Cheng; Dalton, Larry R.

    2004-11-01

    We present a simple and effective method for the postfabrication trimming of optical microresonators. We photobleach CLD-1 chromophores to tune the resonance wavelengths of polymer microring resonator optical notch filters. A maximum wavelength shift of -8.73 nm is observed. The resonators are fabricated with a soft-lithography molding technique and have an intrinsic Q value of 2.6×10^4 and a finesse of 9.3. The maximum extinction ratio of the resonator filters is -34 dB, indicating that the critical coupling condition has been satisfied.

  11. Overactivity of Liver-Related Neurons in the Paraventricular Nucleus of the Hypothalamus: Electrophysiological Findings in db/db Mice.

    Science.gov (United States)

    Gao, Hong; Molinas, Adrien J R; Miyata, Kayoko; Qiao, Xin; Zsombok, Andrea

    2017-11-15

    Preautonomic neurons in the paraventricular nucleus (PVN) of the hypothalamus play a large role in the regulation of hepatic functions via the autonomic nervous system. Activation of hepatic sympathetic nerves increases glucose and lipid metabolism and contributes to the elevated hepatic glucose production observed in the type 2 diabetic condition. This augmented sympathetic output could originate from altered activity of liver-related PVN neurons. Remarkably, despite the importance of the brain-liver pathway, the cellular properties of liver-related neurons are not known. In this study, we provide the first evidence of overall activity of liver-related PVN neurons. Liver-related PVN neurons were identified with a retrograde, trans-synaptic, viral tracer in male lean and db/db mice and whole-cell patch-clamp recordings were conducted. In db/db mice, the majority of liver-related PVN neurons fired spontaneously; whereas, in lean mice the majority of liver-related PVN neurons were silent, indicating that liver-related PVN neurons are more active in db/db mice. Persistent, tonic inhibition was identified in liver-related PVN neurons; although, the magnitude of tonic inhibitory control was not different between lean and db/db mice. In addition, our study revealed that the transient receptor potential vanilloid type 1-dependent increase of excitatory neurotransmission was reduced in liver-related PVN neurons of db/db mice. These findings demonstrate plasticity of liver-related PVN neurons and a shift toward excitation in a diabetic mouse model. Our study suggests altered autonomic circuits at the level of the PVN, which can contribute to autonomic dysfunction and dysregulation of neural control of hepatic functions including glucose metabolism. SIGNIFICANCE STATEMENT A growing body of evidence suggests the importance of the autonomic control in the regulation of hepatic metabolism, which plays a major role in the development and progression of type 2 diabetes mellitus

  12. Nonlinear effects in varactor-tuned resonators.

    Science.gov (United States)

    Everard, Jeremy; Zhou, Liang

    2006-05-01

    This paper describes the effects of RF power level on the performance of varactor-tuned resonator circuits. A variety of topologies are considered, including series and parallel resonators operating in both unbalanced and balanced modes. As these resonators were designed to produce oscillators with minimum phase noise, the initial small signal insertion loss was set to 6 dB and, hence, QL/Q0 = 1/2. To enable accurate analysis and simulation, S parameter and PSPICE models for the varactors were optimized and developed. It is shown that these resonators start to demonstrate nonlinear operation at very low power levels demonstrating saturation and lowering of the resonant frequency. On occasion squegging is observed for modified bias conditions. The nonlinear effects are dependent on the unloaded Q (Q0), the ratio of loaded to unloaded Q (QL/Q0), the bias voltage, and circuit configurations with typical nonlinear effects occurring at -8 dBm in a circuit with a loaded Q of 63 and a varactor bias voltage of 3 V. Analysis, simulation, and measurements that show close correlation are presented.

  13. Uterine artery embolization angiography and fertility related aspects

    Directory of Open Access Journals (Sweden)

    Irina A. Horhoianu

    2016-05-01

    Full Text Available Purpose. Uterine artery embolization is a minimally invasive technique. It applies the principle of targeted anatomical structure devascularisation with utility in fibroid conservative therapy, including for future fertility preserving status. The objective of our paper represents a description and evaluation of angiography utility as a predictive method for fertility maintenance. Material and Methods. The angiography and ultrasound aspects obtained from a prospective study in which selected patients have undergone uterine artery embolization for fertility preservation are detailed. Results. The following angiography aspects have been detected: left- right shunt and utero-ovarian collaterals; these have been compared with the ultrasound aspects related to the fibroid evolution form a volumetric and Doppler ultrasound point of view. The angiographical description predicts the impact on post embolization fibroid evolution and upon fertility. An analysis is made in order to assess the way in which angiography can contribute to fertility alteration. Conclusions. The angiography aspects during embolization and the following ultrasound aspects can represent predictive factors as to fertility evolution after uterine artery embolization.

  14. Comparison of wavelength conversion efficiency between silicon waveguide and microring resonator

    DEFF Research Database (Denmark)

    Xiong, Meng; Ding, Yunhong; Ou, Haiyan

    2016-01-01

    Wavelength conversion based on degenerate four-wave mixing (FWM) was demonstrated and compared between silicon nanowire and microring resonator (MRR). 15 dB enhancement of conversion efficiency (CE) with relatively low input pump power (5 mW) was achieved experimentally in an MRR. The impacts...

  15. Pitavastatin suppresses diethylnitrosamine-induced liver preneoplasms in male C57BL/KsJ-db/db obese mice

    International Nuclear Information System (INIS)

    Shimizu, Masahito; Tanaka, Takuji; Moriwaki, Hisataka; Yasuda, Yoichi; Sakai, Hiroyasu; Kubota, Masaya; Terakura, Daishi; Baba, Atsushi; Ohno, Tomohiko; Kochi, Takahiro; Tsurumi, Hisashi

    2011-01-01

    Obesity and related metabolic abnormalities, including inflammation and lipid accumulation in the liver, play a role in liver carcinogenesis. Adipocytokine imbalances, such as decreased serum adiponectin levels, are also involved in obesity-related liver tumorigenesis. In the present study, we examined the effects of pitavastatin - a drug used for the treatment of hyperlipidemia - on the development of diethylnitrosamine (DEN)-induced liver preneoplastic lesions in C57BL/KsJ-db/db (db/db) obese mice. Male db/db mice were administered tap water containing 40 ppm DEN for 2 weeks and were subsequently fed a diet containing 1 ppm or 10 ppm pitavastatin for 14 weeks. At sacrifice, feeding with 10 ppm pitavastatin significantly inhibited the development of hepatic premalignant lesions, foci of cellular alteration, as compared to that in the untreated group by inducing apoptosis, but inhibiting cell proliferation. Pitavastatin improved liver steatosis and activated the AMPK-α protein in the liver. It also decreased free fatty acid and aminotransferases levels, while increasing adiponectin levels in the serum. The serum levels of tumor necrosis factor (TNF)-α and the expression of TNF-α and interleukin-6 mRNAs in the liver were decreased by pitavastatin treatment, suggesting attenuation of the chronic inflammation induced by excess fat deposition. Pitavastatin is effective in inhibiting the early phase of obesity-related liver tumorigenesis and, therefore, may be useful in the chemoprevention of liver cancer in obese individuals

  16. An improved ultra-wideband bandpass filter design using split ring resonator with coupled microstrip line

    Science.gov (United States)

    Umeshkumar, Dubey Suhmita; Kumar, Manish

    2018-04-01

    This paper incorporates an improved design of Ultra Wideband Bandpass filter by using split ring resonators (SRR) along with the coupled microstrip lines. The use of split ring resonators and shunt step impedance open circuit stub enhances the stability due to transmission zeroes at the ends. The designing of filter and simulation of parameters is carried out using Ansoft's HFSS 13.0 software on RT/Duroid 6002 as a substrate with dielectric constant of 2.94. The design utilizes a frequency band from 22GHz to 29GHz. This band is reserved for Automotive Radar system and sensors as per FCC specifications. The proposed design demonstrates insertion loss less than 0.6dB and return loss better than 12dB at mid frequency i.e. 24.4GHz. The reflection coefficient shows high stability of about 12.47dB at mid frequency. The fractional bandwidth of the proposed filter is about 28.7% and size of filter design is small due to thickness of 0.127mm.

  17. Dysregulation of the unfolded protein response in db/db mice with diet induced steatohepatitis

    OpenAIRE

    Rinella, Mary E.; Siddiqui, M. Shaddab; Gardikiotes, Konstantina; Gottstein, Jeanne; Elias, Marc; Green, Richard M.

    2011-01-01

    In humans with non-alcoholic fatty liver, diabetes is associated with more advanced disease. We have previously shown that diabetic db/db mice are highly susceptible to methionine choline deficient diet (MCD) induced hepatic injury. Since activation of the unfolded protein response (UPR) is an important adaptive cellular mechanism in diabetes, obesity and fatty liver, we hypothesized that dysregulation of the UPR may partially explain how diabetes could promote liver injury.

  18. Selective angiography in fifty patients with primary hepatocellular carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Shou-Zhong, Wang; Xing-Rong, Chen; Gong-Xian, Wang

    1983-06-01

    Selective angiography is of great importance in the diagnosis of primary hepatocellular carcinoma. It offers information on the findings, multicentricity, localisation, extension, and type of growth. This paper discusses angiography from the methodical point of view, the findings to be obtained, the types of hepatocellular carcinoma, and the diagnostic efficiency of selective angiography in the evaluation of this type of tumour.

  19. Novel anti-diabetic effect of SCM-198 via inhibiting the hepatic NF-κB pathway in db/db mice.

    Science.gov (United States)

    Huang, Hui; Xin, Hong; Liu, Xinhua; Xu, Yajun; Wen, Danyi; Zhang, Yahua; Zhu, Yi Zhun

    2012-04-01

    There are reports of early evidence that suggest the involvement of chronic low-grade inflammation in the pathogenesis of Type 2 diabetes. Thus, substances that have effects in reducing inflammation could be potential drugs for Type 2 diabetes. Leonurine (4-guanidino-n-butyl syringate; SCM-198) is an alkaloid in HL (Herba leonuri), which was reported to possess anti-inflammatory properties. We hypothesize that SCM-198 may have beneficial effects on Type 2 diabetes. In the present study, we attempted to test this hypothesis by evaluating the anti-diabetic effect of SCM-198 and the possible underlying mechanisms of its effects in db/db mice. SCM-198 (50, 100 and 200 mg/kg of body weight), pioglitazone (50 mg/kg of body weight, as a positive control) or 1% CMC-Na (sodium carboxymethylcellulose) were administered to the db/db or db/m mice once daily for 3 weeks. After 3 weeks, SCM-198 (200 mg/kg of body weight) treatment significantly reduced the fasting blood glucose level and increased the plasma insulin concentration in the db/db mice, meanwhile it significantly lowered the plasma TAG (triacylglycerol) concentration and increased the HDL (high-density lipoprotein)-cholesterol concentration. Moreover, the dysregulated transcription of the hepatic glucose metabolic enzymes, including GK (glucokinase), G6Pase (glucose-6-phosphatase) and PEPCK (phosphoenolpyruvate carboxykinase), was recovered by an Akt-dependent pathway. The pro-inflammatory mediators {such as TNFα (tumour necrosis factor α), IL (interleukin)-6, IL-1β, degradation of IκB [inhibitor of NF-κB (nuclear factor-κB)] α and thereafter activation of NF-κB} were reversed by SCM-198 treatment in the db/db mice. The present study provides first evidence that SCM-198 exhibits anti-inflammatory activity and has an ameliorating effect on diabetic symptoms via inhibiting of NF-κB/IKK (IκB kinase) pathway. Consequently, we suggest that SCM-198 may be a prospective agent for prevention and

  20. Digital angiography and surgery in the same room

    International Nuclear Information System (INIS)

    Goldman, M.L.; Hack, S.N.; Sarrafizadeh, M.S.; Marar, H.G.; Behar, D.J.; Chigurupati, R.C.; Klein, S.I.; Widlus, D.M.; Fortune, J.B.

    1986-01-01

    Albany Medical Center and private industries (XRE and United X-ray corporations) have collaborated to develop a room within the operating suite that allows high-speed and high-resolution digital angiography and surgery to be performed simultaneously. Patients who have sustained massive trauma can be transferred directly from the ambulance to this new facility. While the patient is undergoing exploratory laparotomy, other vital areas of the body can be evaluated by angiography. This combined approach of surgery and angiography has also led to improved management of patients with massive or occult intestinal hemorrhage and patients with peripheral vascular disease. Other patients undergoing difficult emergency or elective surgery, as in the biliary tract, can now have available the benefits of an operating room facility that also allows high-resolution fluoroscopy and complete angiography to be undertaken

  1. Exploratory use of cardiovascular magnetic resonance imaging in liver transplantation: a one-stop shop for preoperative cardiohepatic evaluation.

    Science.gov (United States)

    Reddy, Sahadev T; Thai, Ngoc L; Fakhri, Asghar A; Oliva, Jose; Tom, Kusum B; Dishart, Michael K; Doyle, Mark; Yamrozik, June A; Williams, Ronald B; Grant, Saundra B; Poydence, Jacqueline; Shah, Moneal; Singh, Anil; Nathan, Swami; Biederman, Robert W W

    2013-11-15

    Preoperative cardiovascular risk stratification in orthotopic liver transplantation candidates has proven challenging due to limitations of current noninvasive modalities. Additionally, the preoperative workup is logistically cumbersome and expensive given the need for separate cardiac, vascular, and abdominal imaging. We evaluated the feasibility of a "one-stop shop" in a magnetic resonance suite, performing assessment of cardiac structure, function, and viability, along with simultaneous evaluation of thoracoabdominal vasculature and liver anatomy. In this pilot study, patients underwent steady-state free precession sequences and stress cardiac magnetic resonance (CMR), thoracoabdominal magnetic resonance angiography, and abdominal magnetic resonance imaging (MRI) on a standard MRI scanner. Pharmacologic stress was performed using regadenoson, adenosine, or dobutamine. Viability was assessed using late gadolinium enhancement. Over 2 years, 51 of 77 liver transplant candidates (mean age, 56 years; 35% female; mean Model for End-stage Liver Disease score, 10.8; range, 6-40) underwent MRI. All referred patients completed standard dynamic CMR, 98% completed stress CMR, 82% completed late gadolinium enhancement for viability, 94% completed liver MRI, and 88% completed magnetic resonance angiography. The mean duration of the entire study was 72 min, and 45 patients were able to complete the entire examination. Among all 51 patients, 4 required follow-up coronary angiography (3 for evidence of ischemia on perfusion CMR and 1 for postoperative ischemia), and none had flow-limiting coronary disease. Nine proceeded to orthotopic liver transplantation (mean 74 days to transplantation after MRI). There were six ascertained mortalities in the nontransplant group and one death in the transplanted group. Explant pathology confirmed 100% detection/exclusion of hepatocellular carcinoma. No complications during CMR examination were encountered. In this proof-of-concept study, it

  2. Correlation of angiography and MR imaging in cerebral vasculitis

    International Nuclear Information System (INIS)

    Cloft, H.J.; Phillips, C.D.; Dix, J.E.; McNulty, B.C.; Kallmes, D.F.; Zagardo, M.T.

    1999-01-01

    Purpose: MR imaging and cerebral angiography were correlated in patients with primary angiitis of the central nervous system (PACNS) to assess the relative roles of these imaging modalities in the diagnosis. Material and Methods: In 9 patients, MR imaging and angiography were compared with regard to the relative involvement of each major vascular territory. Vascular territories assessed were the anterior, middle, and posterior cerebral arteries, and the posterior fossa. Results: All patients had angiographic findings consistent with vasculitis in multiple vascular territories. MR findings ranged from normal to diffusely abnormal. One patient had a completely normal MR investigation. Of 50 territories affected by vasculitis on angiography, 17 (34%) were normal on MR. Conclusion: Relative to cerebral angiography, MR imaging is a poor indicator of the presence or absence of PACNS. Angiography is indicated when clinical suspicion of PACNS is strong, regardless of the findings on MR. (orig.)

  3. Pluronic L-81 ameliorates diabetic symptoms in db/db mice through transcriptional regulation of microsomal triglyceride transfer protein

    Science.gov (United States)

    Au, Wo-Shing; Lu, Li-Wei; Tam, Sidney; Ko, Otis King Hung; Chow, Billy KC; He, Ming-Liang; Ng, Samuel S; Yeung, Chung-Man; Liu, Ching-Chiu; Kung, Hsiang-Fu; Lin, Marie C

    2009-01-01

    AIM: To test whether oral L-81 treatment could improve the condition of mice with diabetes and to investigate how L-81 regulates microsomal triglyceride transfer protein (MTP) activity in the liver. METHODS: Genetically diabetic (db/db) mice were fed on chow supplemented with or without L-81 for 4 wk. The body weight, plasma glucose level, plasma lipid profile, and adipocyte volume of the db/db mice were assessed after treatment. Toxicity of L-81 was also evaluated. To understand the molecular mechanism, HepG2 cells were treated with L-81 and the effects on apolipoprotein B (apoB) secretion and mRNA level of the MTP gene were assessed. RESULTS: Treatment of db/db mice with L-81 significantly reduced and nearly normalized their body weight, hyperphagia and polydipsia. L-81 also markedly decreased the fasting plasma glucose level, improved glucose tolerance, and attenuated the elevated levels of plasma cholesterol and triglyceride. At the effective dosage, little toxicity was observed. Treatment of HepG2 cells with L-81 not only inhibited apoB secretion, but also significantly decreased the mRNA level of the MTP gene. Similar to the action of insulin, L-81 exerted its effect on the MTP promoter. CONCLUSION: L-81 represents a promising candidate in the development of a selective insulin-mimetic molecule and an anti-diabetic agent. PMID:19554651

  4. A comparison of patient dose levels between 3/4 vessel conventional angiography and computed tomography angiography during examinations to investigate subarachnoid haemorrhage

    International Nuclear Information System (INIS)

    Spanton, David; Strudwick, Ruth M.

    2007-01-01

    The aim of this study was to investigate and compare the levels of ionising radiation dose received by patients whilst undergoing radiological examination for Subarachnoid haemorrhage by conventional angiography (single and bi plane) and computed tomography angiography. The results obtained from previous examinations have been compared to consider which method of investigation delivers the lowest ionising radiation dose to the patient. Consideration was also given to comparing single plane angiography to bi plane angiography as empirical evidence suggested that radiologists received no formal training and only a small amount of informal training on newly installed equipment at the hospital in which the research was carried out. Would this lead to patients being inadvertently exposed to increased radiation as radiologists familiarised themselves with the equipment? The dose received by 30 patients examined for SAH by each modality was converted to effective dose (mSv) for comparison. These results were then further compared by removing the lowest and highest recorded doses to eliminate any bias that may have been caused by skewed data. The results showed that CTA consistently delivered a lower dose to patients than single or bi plane angiography and that bi plane delivered a lower mean average dose than single plane angiography, with or without any skewed data

  5. Fluorescence angiography in retinal tumours

    Energy Technology Data Exchange (ETDEWEB)

    Fuhrmann, M [Staedtisches Klinikum Berlin-Buch (German Democratic Republic)

    1980-01-01

    On the basis of the available photographic material the results of fluorescein angiography are reported in 4 cases of retinoblastoma and 3 cases of Bourneville's disease. The clinical diagnosis of retinoblastoma was confirmed histologically in all cases since the first eye had been removed for the same reason previously. One child had not yet been treated, and in 3 cases radioactive isotopes were used in the treatment. In the group of phacomatosis the patients had only periodical outpatient examinations. The importance of this angiography in the diagnosis and follow-up of these diseases is stressed.

  6. Cerebrovascular reactivity by quantitative magnetic resonance angiography with a co2 challenge. Validation as a new imaging biomarker

    International Nuclear Information System (INIS)

    Caputi, Luigi; Ghielmetti, Francesco; Faragò, Giuseppe; Longaretti, Fabio; Lamperti, Massimo; Anzola, Gian Paolo; Carriero, Maria Rita; Charbel, Fady T.; Bruzzone, Maria Grazia; Parati, Eugenio; Ciceri, Elisa

    2014-01-01

    Assessment of cerebrovascular reactivity (CVR) is essential in cerebrovascular diseases, as exhausted CVR may enhance the risk of cerebral ischemic events. Transcranial Doppler (TCD) with a vasodilatory stimulus is currently used for CVR evaluation. Scanty data are available for Quantitative Magnetic Resonance Angiography (QMRA), which supplies higher spatial resolution and quantitative cerebral blood flow values. Aims of our pilot study were: (a) to assess safety and feasibility of CO 2 administration during QMRA, (b) evaluation of CVR under QMRA compared to TCD, and (c) quantitative evaluation of blood flow from the major intracranial arterial vessels both at rest and after CO 2 . CVR during 5% CO 2 air breathing was measured with TCD as a reference method and compared with QMRA. Fifteen healthy subjects (age 60.47 ± 2.24; male 11/15) were evaluated at rest and during CO 2 challenge. Feasibility and safety of QMRA under CO 2 were ensured in all subjects. CVR from middle cerebral artery territory was not statistically different between TCD and MRI (p > 0.05). Mean arterial pressure (MAP) and heart rate (HR) increased during QMRA and TCD (MAP p = 0.007 and p = 0.001; HR p = 0.043 and p = 0.068, respectively). Blood flow values from all intracranial vessels increased after CO 2 inhalation (p < 0.001). CO 2 administration during QMRA sessions is safe and feasible. Good correlation in terms of CVR was obtained comparing TCD and QMRA. Blood flow values significantly increased from all intracranial arterial vessels after CO 2 . Studies regarding CVR in physiopathological conditions might consider the utilization of QMRA both in routine clinical settings and in research projects

  7. Dapagliflozin Aggravates Renal Injury via Promoting Gluconeogenesis in db/db Mice.

    Science.gov (United States)

    Jia, Yingli; He, Jinzhao; Wang, Liang; Su, Limin; Lei, Lei; Huang, Wei; Geng, Xiaoqiang; Zhang, Shun; Meng, Xiaolu; Zhou, Hong; Yang, Baoxue

    2018-01-01

    A sodium-glucose co-transporter-2 inhibitor dapagliflozin is widely used for lowering blood glucose and its usage is limited in type 2 diabetes mellitus patients with moderate renal impairment. As its effect on kidney function is discrepant and complicated, the aim of this study is to determine the effect of dapagliflozin on the progression of diabetic nephropathy and related mechanisms. Twelve-week-old male C57BL/6 wild-type and db/db mice were treated with vehicle or 1 mg/kg dapagliflozin for 12 weeks. Body weight, blood glucose, insulin tolerance, glucose tolerance, pyruvate tolerance and 24-hour urine were measured every 4 weeks. At 24 weeks of age, renal function was evaluated by blood urea nitrogen level, creatinine clearance, urine output, urinary albumin excretion, Periodic Acid-Schiff staining, Masson's trichrome staining and electron microscopy. Changes in insulin signaling and gluconeogenic key regulatory enzymes were detected using Western blot analysis. Dapagliflozin did not alleviate but instead aggravated diabetic nephropathy manifesting as increased levels of microalbuminuria, blood urea nitrogen, and glomerular and tubular damage in db/db mice. Despite adequate glycemic control by dapagliflozin, urinary glucose excretion increased after administration before 24 weeks of age and was likely associated with renal impairment. Increased urinary glucose excretion was mainly derived from the disturbance of glucose homeostasis with elevated hepatic and renal gluconeogenesis induced by dapagliflozin. Although it had no effect on insulin sensitivity and glucose tolerance, dapagliflozin further induced the expression of gluconeogenic key rate-limiting enzymes through increasing the expression levels of FoxO1 in the kidney and liver. These experimental results indicate that dapagliflozin aggravates diabetes mellitus-induced kidney injury, mostly through increasing gluconeogenesis. © 2018 The Author(s). Published by S. Karger AG, Basel.

  8. Design of Compact Wilkinson Power Divider with Harmonic Suppression using T-Shaped Resonators

    Science.gov (United States)

    Siahkamari, Hesam; Yasoubi, Zahra; Jahanbakhshi, Maryam; Mousavi, Seyed Mohammad Hadi; Siahkamari, Payam; Nouri, Mohammad Ehsan; Azami, Sajad; Azadi, Rasoul

    2018-04-01

    A novel scheme of a shrunken Wilkinson power divider with harmonic suppression, using two identical resonators in the conventional Wilkinson power divider is designed. Moreover, the LC equivalent circuit and its relevant formulas are provided. To substantiate the functionality and soundness of design, a microstrip implementation of this design operating at 1 GHz with the second to eighth harmonic suppression, is developed. The proposed circuit is relatively smaller than the conventional circuit, (roughly 55% of the conventional circuit). Simulation and measurement results for the proposed scheme, which are highly consistent with one another, indicate a good insertion loss about 3.1 dB, input return loss of 20 dB and isolation of 20 dB, while sustaining high-power handling capability over the Wilkinson power divider.

  9. CT and MR angiography

    International Nuclear Information System (INIS)

    Bert, A.L.; Marshal, G.

    1995-01-01

    CT-angiography is a new vessel imaging technique based on the volumetric scanning of the region of interst during the first pass of IV bolus injection of contrast medium. MR-angiography is a titally noninvasive technique. The differentiation of flowing blood from the adjecent stationary tissues is based on the detection of blood motion. The flowing blood is highlighted with white light. CT- and MR-angiographic techniques are used to establish% stenoses and occlusions in intracranial arteries; aneurisms; trombosis of intracranial veins and venous angioma; diseases of neck vessels, thoracic vessels, abdominal vessels. Blood flow direction in cirrotic patients with portal hypertension can be determined in the portal vein, as well as the presence of thrombosis

  10. The antidiabetic effects of a dry powder of dietary vegetable and fruit mixtures in diabetic db/db mice

    Directory of Open Access Journals (Sweden)

    Chung-Man Yeung

    2008-09-01

    Full Text Available Chung-Man Yeung1, Yi Tan1, Sidney Tam2, Liwei Lu3, King-Hung Ko3, Pai-Hao Yang1,4, Hsiang-Fu Kung4, Marie C Lin11Department of Chemistry, Open Laboratory of Chemical Biology of the Institute of Molecular Technology, 2Clinical Biochemistry Unit, 3Department of Pathology, The University of Hong Kong, Hong Kong, China; 4Centre of Emerging Infectious Diseases, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, ChinaAbstract: We evaluated the antidiabetic effects of a mixed vegetable powder-formula I (MVP-FI, which is a dry powder mixture of over 65 kinds of vegetables and fruits, using the db/db type 2 diabetes mouse model. The db/db mice at 8–10 weeks of age were randomly divided into three groups: vehicle treatment, 1.575 g/kg MVP-FI treatment, and 3.15 g/kg MVP-FI treatment. During 12 days of treatment, we measured food intake and body weight changes, fasting blood glucose levels, and plasma lipid levels. Our results showed that the food intake and the body weight of MVP-FI-treated group were decreased gradually. Moreover, the fasting blood glucose level of the treated group was significantly dropped to a normal level comparable to that of the lean mice. Furthermore, we also found that the plasma triglyceride level in the treated group was dropped, whereas the high-density lipoprotein (HDL level was increased and total cholesterol/HDL-cholesterol ratio was decreased. Taken together, these results suggest that the diabetic conditions of the db/db mice have been improved after 12 days treatment with MVP-FI. The antihyperglycemic and antiobese activities of the MVP-FI, as demonstrated in the present study, may have important clinical implications for improving the management of type 2 diabetic patients.Keywords: traditional Chinese medicine (TCM, db/db mice, diabetes

  11. The role of MR angiography before transjugular placement of a portosystemic stent shunt (TIPS)

    International Nuclear Information System (INIS)

    Mueller, M.F.; Siewert, B.; Kim, D.; Edelman, R.R.; Stokes, K.R.; Finn, J.P.

    1994-01-01

    The authors employed magnetic resonance angiography (MRA) to guide catheter placement for transjugular intrahepatic portosystemic stent shunt (TIPS) procedures in 14 of 24 patients, and compared the results to the 10 patients who did not have prior panning based on MRA. Two-dimensional time-of-flight venography was performed during breath holding, and projection venograms were formatted in sagittal, coronal and axial planes. MRA defined venous anatomy sufficiently well to shorten the procedure and helped to minimize invasiveness. With MRA guidance, intrahepatic needle punctures were significantly fewer (without MRA guidance: mean 12.1; with MRA guidance: mean 3.5, p [de

  12. Transient Global Amnesia following Neural and Cardiac Angiography May Be Related to Ischemia

    Directory of Open Access Journals (Sweden)

    Hongzhou Duan

    2016-01-01

    Full Text Available Introduction. Transient global amnesia (TGA following angiography is rare, and the pathogenesis has not been illustrated clearly till now. The aim of this research is to explore the pathogenesis of TGA following angiography by analyzing our data and reviewing the literature. Methods. We retrospectively studied 20836 cases with angiography in our hospital between 2007 and 2015 and found 9 cases with TGA following angiography. The data of these 9 cases were analyzed. Results. We found all 9 cases with TGA following neural angiography (5 in 4360 or cardiac angiography (4 in 8817 and no case with TGA following peripheral angiography (0 in 7659. Statistical difference was found when comparing the neural and cardiac angiography group with peripheral group (p=0.022. Two cases with TGA were confirmed with small acute infarctions in hippocampus after angiography. This might be related to the microemboli which were rushed into vertebral artery following blood flow during neural angiography or cardiac angiography. There was no statistical difference when comparing the different approaches for angiography (p=0.82 and different contrast agents (p=0.619. Conclusion. Based on the positive findings of imaging study and our analysis, we speculate that ischemia in the medial temporal lobe with the involvement of the hippocampus might be an important reason of TGA following angiography.

  13. The comparative study on diagnostic validity of cerebral aneurysm by computed tomography angiography versus digital subtraction angiography after subarachnoid hemorrhage

    Directory of Open Access Journals (Sweden)

    Masih Saboori

    2011-01-01

    Full Text Available Background: In order to declare the preoperative diagnostic value of brain aneurysms, two radiological modalities, computed tomographic angiography and digital subtraction angiography were compared. Methods: In this descriptive analytic study, diagnostic value of computed tomographic angiography (CTA was com-pared with digital subtraction angiography (DSA. Sensitivity, specificity, positive and negative predictive values were calculated and compared between the two modalities. All data were analyzed with SPSS software, version 16. Results: Mean age of patients was 49.5 ± 9.13 years. 57.9 % of subjects were female. CTA showed 89% sensitivity and 100% specificity whereas DSA demonstrated 74% sensitivity and 100% specificity. Positive predictive value of both methods was 100%, but negative predictive value of CTA and DSA was 85% and 69%, respectively. Conclusions: Based on our data, CTA is a valuable diagnostic modality for detection of brain aneurysm and su-barachnoid hemorrhage.

  14. Diet supplementation with green tea extract epigallocatechin gallate prevents progression to glucose intolerance in db/db mice

    Directory of Open Access Journals (Sweden)

    Ortsäter Henrik

    2012-02-01

    Full Text Available Abstract Background Green tea was suggested as a therapeutic agent for the treatment of diabetes more than 70 years ago, but the mechanisms behind its antidiabetic effect remains elusive. In this work, we address this issue by feeding a green tea extract (TEAVIGO™ with a high content of epigallocatechin gallate (EGCG or the thiazolidinedione PPAR-γ agonist rosiglitazone, as positive control, to db/db mice, an animal model for diabetes. Methods Young (7 week-old db/db mice were randomized and assigned to receive diets supplemented with or without EGCG or rosiglitazone for 10 weeks. Fasting blood glucose, body weight and food intake was measured along the treatment. Glucose and insulin levels were determined during an oral glucose tolerance test after 10 weeks of treatment. Pancreata were sampled at the end of the study for blinded histomorphometric analysis. Islets were isolated and their mRNA expression analyzed by quantitative RT-PCR. Results The results show that, in db/db mice, EGCG improves glucose tolerance and increases glucose-stimulated insulin secretion. EGCG supplementation reduces the number of pathologically changed islets of Langerhans, increases the number and the size of islets, and heightens pancreatic endocrine area. These effects occurred in parallel with a reduction in islet endoplasmic reticulum stress markers, possibly linked to the antioxidative capacity of EGCG. Conclusions This study shows that the green tea extract EGCG markedly preserves islet structure and enhances glucose tolerance in genetically diabetic mice. Dietary supplementation with EGCG could potentially contribute to nutritional strategies for the prevention and treatment of type 2 diabetes.

  15. Oligonol, a low-molecular-weight polyphenol derived from lychee fruit, attenuates diabetes-induced renal damage through the advanced glycation end product-related pathway in db/db mice.

    Science.gov (United States)

    Park, Chan Hum; Yokozawa, Takako; Noh, Jeong Sook

    2014-08-01

    This study was conducted to examine whether oligonol, a low-molecular-weight polyphenol derived from lychee fruit, has an ameliorative effect on diabetes-induced alterations, such as advanced glycation end product (AGE) formation or apoptosis in the kidneys of db/db mice with type 2 diabetes. Oligonol [10 or 20 mg/(kg body weight · d), orally] was administered every day for 8 wk to prediabetic db/db mice, and its effect was compared with vehicle-treated db/db and normal control mice (m/m). The administration of oligonol decreased the elevated renal glucose concentrations and reactive oxygen species in db/db mice (P factor-α (P related variables, representing renoprotective effects against the development of diabetic complications in db/db mice with type 2 diabetes. © 2014 American Society for Nutrition.

  16. Magnetic resonance imaging of the coronary arteries: clinical results from three dimensional evaluation of a respiratory gated technique

    NARCIS (Netherlands)

    R.J.M. van Geuns (Robert Jan); H.G. de Bruin (Hein); B.J.W.M. Rensing (Benno); P.A. Wielopolski (Piotr); M.D. Hulshoff; P.M.A. van Ooijen (Peter); M. Oudkerk (Matthijs); P.J. de Feyter (Pim)

    1999-01-01

    textabstractBACKGROUND: Magnetic resonance coronary angiography is challenging because of the motion of the vessels during cardiac contraction and respiration. Additional challenges are the small calibre of the arteries and their complex three dimensional course. Respiratory

  17. Development of serial magnification angiography and its clinical significance

    International Nuclear Information System (INIS)

    Sasaki, Tsuneo; Matsubara, Kazuhito; Ishiguchi, Tsuneo; Mashita, Shinichi; Kaii, Osamu

    1979-01-01

    In order to apply serial magnification angiography to clinical examinations so easily, a serial cardioangiography apparatus was equipped with a tube having 0.1 mm focal spot and with DRX-431HD diode. A CAT-FK Type catheter bed (Toshiba) was used as a roentgenographic table and a PUCK film changer was used. Thus, serial magnification angiography can be easily used to clinical examinations, and can be set in a usual x-ray photographic studio. Serial magnification angiography was used to examine the cerebral vessels in 6 patients, vessels of the pulmonary circulation in 1 patient, bronchial arteries in 6 patients, the celiac artery in 18 patients, the superior mesenteric artery in 2 patients, inferior mesenteric artery in 2 patients, the renal artery in 2 patients, and the adrenal vein in 7 patients. Owing to this angiography, minute changes in the vessel in the lesion can be observed and fine neovascularity can be detected. Thus, serial magnification angiography makes diagnoses of vascular disorders easier. (Ichikawa, K.)

  18. Standardized cardiovascular magnetic resonance imaging (CMR protocols, society for cardiovascular magnetic resonance: board of trustees task force on standardized protocols

    Directory of Open Access Journals (Sweden)

    Kim Raymond J

    2008-07-01

    Full Text Available Index 1. General techniques 1.1. Stress and safety equipment 1.2. Left ventricular (LV structure and function module 1.3. Right ventricular (RV structure and function module 1.4. Gadolinium dosing module. 1.5. First pass perfusion 1.6. Late gadolinium enhancement (LGE 2. Disease specific protocols 2.1. Ischemic heart disease 2.1.1. Acute myocardial infarction (MI 2.1.2. Chronic ischemic heart disease and viability 2.1.3. Dobutamine stress 2.1.4. Adenosine stress perfusion 2.2. Angiography: 2.2.1. Peripheral magnetic resonance angiography (MRA 2.2.2. Thoracic MRA 2.2.3. Anomalous coronary arteries 2.2.4. Pulmonary vein evaluation 2.3. Other 2.3.1. Non-ischemic cardiomyopathy 2.3.2. Arrhythmogenic right ventricular cardiomyopathy (ARVC 2.3.3. Congenital heart disease 2.3.4. Valvular heart disease 2.3.5. Pericardial disease 2.3.6. Masses

  19. Angiography of the upper extremity

    International Nuclear Information System (INIS)

    Janevski, B.K.

    1982-01-01

    This thesis provides a description of the technical and medical aspects of arteriography of the upper extremity and an extensive analysis of the angiographic anatomy and pathology of 750 selective studies performed in more than 500 patients. A short historical review is provided of angiography as a whole and of arteriography of the hand in particular. The method of percutaneous transfemoral catheterization of the arteries of the upper extremity and particularly the arteries of the hand is considered, discussing the problems the angiographer encounters frequently, describing the angiographic complications which may occur and emphasizing the measures to keep them to a minimum. The use of vasodilators in hand angiography is discussed. A short description of the embryological patterns persisting in the arteries of the arm is included in order to understand the congenital variations of the arteries of the upper extremity. The angiographic patterns and clinical aspects of the most common pathological processes involving the arteries of the upper extremities are presented. Special attention is paid to the correlation between angiography and pathology. (Auth.)

  20. Effective selection of hypertensive patients for angiography

    International Nuclear Information System (INIS)

    van der Voorde, F.; Derkx, F.H.M.; Bossuyt, P.M.M.; Segaar, R.W.; de Wind, A.; Pieterman, H.

    1989-01-01

    The authors prospectively observed 373 severe hypertensives with either diastolic blood pressure (BP) ≥ 105 and age ≤ 40, or BP with three drugs ≥ 105 (regardless of age). Excluded were patients who were older than 75 or who had creatinine >400. History, physical examination, and laboratory data were used to identify high-yield criteria for arteriography. All patients underwent angiography as the gold standard; angiography showed 127 unilateral renal artery stenoses, 73 bilateral renal artery stenoses, and 173 (nonstenosed) essential hypertensives. The authors constructed a logistic regression model of height, weight, age, smoking, and hypertension duration, which could be used to identify 90% of stenosed patients with 50% fewer angiographies in the essential hypertensives

  1. MiR-138 promotes smooth muscle cells proliferation and migration in db/db mice through down-regulation of SIRT1

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Juan [Department of Gynecology, Changzhou Maternity and Children Health Hospital, Changzhou, Jiangsu 213003 (China); Li, Li; Yun, Hui-fang [Department of Anesthesiology, Changzhou No. 2 People' s Hospital, Changzhou, Jiangsu 213003 (China); Han, Ye-shan, E-mail: yeshanhan123@163.com [Department of Anesthesiology, Changzhou No. 2 People' s Hospital, Changzhou, Jiangsu 213003 (China)

    2015-08-07

    Background: Diabetic vascular smooth muscle cells (VSMCs) exhibit significantly increased rates of proliferation and migration, which was the most common pathological change in atherosclerosis. In addition, the study about the role for miRNAs in the regulation of VSMC proliferation is just beginning to emerge and additional miRNAs involved in VSMC proliferation modulation should be identified. Methods: The expression of miR-138 and SIRT1 were examined in SMCs separated from db/db mice and in SMC lines C-12511 exposed to high glucose with qRT-PCR and western blot. The regulation of miR-138 on the expression of SMCs was detected with luciferase report assay. VSMCs proliferation and migration assays were performed to examine the effect of miR-138 inhibitor on VSMCs proliferation and migration. Results: We discovered that higher mRNA level of miR-138 and reduced expression of SIRT1 were observed in SMCs separated from db/db mice and in SMC lines C-12511. Moreover, luciferase report assay showed that the activity of SIRT1 3′-UTR was highly increased by miR-138 inhibitor and reduced by miR-138 mimic. In addition, we examined that the up-regulation of NF-κB induced by high glucose in SMCs was reversed by resveratrol and miR-138 inhibitor. MTT and migration assays showed that miR-138 inhibitor attenuated the proliferation and migration of smooth muscle cells. Conclusion: In this study, we revealed that miR-138 might promote proliferation and migration of SMC in db/db mice through suppressing the expression of SIRT1. - Highlights: • Higher mRNA level of miR-138 was observed in SMCs from db/db mice. • The mRNA and protein level of SIRT1 in SMCs from db/db mice were greatly reduced. • miR-138 could regulate the expression of SIRT1 in SMCs. • SIRT1 overexpression reversed the up-regulation of acetylized p65 and NF-κB induced by high glucose. • MiR-138 inhibitor reversed VSMCs proliferation and migration induced by high glucose.

  2. Bilateral renal cell carcinoma in a horseshoe kidney: preoperative assessment with MRI and digital subtraction angiography

    International Nuclear Information System (INIS)

    Schubert, R.A.; Soeldner, J.; Kaiser, W.A.; Steiner, T.; Schubert, J.

    1998-01-01

    Renal cell carcinoma in a horseshoe kidney is an unusual entity. To our knowledge, only 123 cases have been published to date. We report the first bilateral case of two clear-cell carcinomas in an asymmetrically fused kidney. Optimum preservation of renal function after radical tumor removal requires accurate preoperative imaging. Since the vascular supply in fusion anomalies is extremely variable, angiography is mandatory. Magnetic resonance imaging was most suitable to predict the tumor extent and localization, because it simultaneously gave the most comprehensive anatomical overview of the malformation. (orig.)

  3. Digital subtraction cerebral angiography by intraarterial injection: comparison with conventional angiography

    International Nuclear Information System (INIS)

    Brant-Zawadzki, M.; Gould, R.; Norman, D.; Newton, T.H.; Lane, B.

    1983-01-01

    For 4 months, a prototype digital subtraction system was used to obtain images of the cerebral vasculature after intraarterial contrast injections. In 12 instances, the intraarterial injections were recorded with both a digital subtraction unit and conventional direct magnification film-screen system. The digital subtraction and conventional film subtraction images were compared and graded for quality and information content by three skilled observers. In addition, quantitative measurements of contrast-detail performance and spatial resolution were obtained on both the digital system and the screen-film imaging chain. In a clinical setting, both the digital subtraction and conventional film-screen systems provided similar quality images and angiographic information. Contrast-detail curves demonstrated that digital subtraction angiography outperformed conventional film technique for low-contrast objects. Digital subtraction angiography also reduced the time required to obtain the angiogram, markedly reduced film cost, and lowered the contrast agent burden

  4. Fluorescence angiography in retinal tumours

    International Nuclear Information System (INIS)

    Fuhrmann, M.

    1980-01-01

    On the basis of the available photographic material the results of fluorescein angiography are reported in 4 cases of retinoblastoma and 3 cases of Bourneville's disease. The clinical diagnosis of retinoblastoma was confirmed histologically in all cases since the first eye had been removed for the same reason previously. One child had not yet been treated, and in 3 cases radioactive isotopes were used in the treatment. In the group of phacomatosis the patients had only periodical outpatient examinations. The importance of this angiography in the diagnosis and follow-up of these diseases is stressed. (author)

  5. Optimization of Ecg Gating in Quantitative Femoral Angiography

    International Nuclear Information System (INIS)

    Nilsson, S.; Berglund, I.; Erikson, U.; Johansson, J.; Walldius, G.

    2003-01-01

    Purpose: To determine which phase of the heart cycle would yield the highest reproducibility in measuring atherosclerosis-related variables such as arterial lumen volume and edge roughness. Material and Methods: 35 patients with hypercholesterolemia underwent select ive femoral angiography, repeated four times at 10-min intervals. The angiographies were performed with Ecg-gated exposures. In angiographies 1 and 2 the delay from R-wave maximum to each exposure was 0.1 s, in angiographies 3 and 4 the delay was 0.1, 0.3, 0.5 or 0.7 s or the exposures were performed 1/s without Ecg gating. Arterial lumen volume and edge roughness were measured in a 20-cm segment of the superficial femoral artery using a computer-based densitometric method. Measurement reproducibility was determined by comparing angiographies 1-2 and angiographies 3-4. Results: When measuring arterial lumen volume and edge roughness of a 20-cm segment of the femoral artery, reproducibility was not dependent on Ecg gating. In measuring single arterial diameters and cross-sectional areas, the reproducibility was better when exposures were made 0.1 s after the R-wave maximum than when using other settings of the Ecg gating device or without Ecg gating. Conclusion: The influence of pulsatile flow upon quantitative measurement in femoral angiograms seems to be the smallest possible in early systole, as can be demonstrated when measuring single diameters and cross-sectional areas. In variables based on integration over longer segments, measurement reproducibility seems to be independent of phase

  6. Optimization of Ecg Gating in Quantitative Femoral Angiography

    Energy Technology Data Exchange (ETDEWEB)

    Nilsson, S.; Berglund, I.; Erikson, U. [Univ. Hospital, Uppsala (Sweden). Dept. of Oncology, Radiology and Clinical Immunology; Johansson, J.; Walldius, G. [Karolinska Hospital, Stockholm (Sweden). King Gustav V Research Inst.

    2003-09-01

    Purpose: To determine which phase of the heart cycle would yield the highest reproducibility in measuring atherosclerosis-related variables such as arterial lumen volume and edge roughness. Material and Methods: 35 patients with hypercholesterolemia underwent select ive femoral angiography, repeated four times at 10-min intervals. The angiographies were performed with Ecg-gated exposures. In angiographies 1 and 2 the delay from R-wave maximum to each exposure was 0.1 s, in angiographies 3 and 4 the delay was 0.1, 0.3, 0.5 or 0.7 s or the exposures were performed 1/s without Ecg gating. Arterial lumen volume and edge roughness were measured in a 20-cm segment of the superficial femoral artery using a computer-based densitometric method. Measurement reproducibility was determined by comparing angiographies 1-2 and angiographies 3-4. Results: When measuring arterial lumen volume and edge roughness of a 20-cm segment of the femoral artery, reproducibility was not dependent on Ecg gating. In measuring single arterial diameters and cross-sectional areas, the reproducibility was better when exposures were made 0.1 s after the R-wave maximum than when using other settings of the Ecg gating device or without Ecg gating. Conclusion: The influence of pulsatile flow upon quantitative measurement in femoral angiograms seems to be the smallest possible in early systole, as can be demonstrated when measuring single diameters and cross-sectional areas. In variables based on integration over longer segments, measurement reproducibility seems to be independent of phase.

  7. Spiral CT angiography of middle cerebral artery stenoses

    International Nuclear Information System (INIS)

    Lehmann, K.J.; Neff, K.W.; Ries, S.; Sommer, A.; Steinke, W.; Georgi, M.

    1996-01-01

    Transcranial Doppler ultrasonography (TCD) and magnetic resonance angiography (MRA) are well-established techniques for ascertaining intracranial obstructive artery disease. The short examination time required for additional helical CT angiography (CTA) allows quick management of emergency patients already undergoing native CT. However, today the ability of CTA to detect stenoses of the middle cerebral artery (MCA) has not been proven. To analyse the value of CTA in the classification of atherosclerotic disease 23 MCA stenoses confirmed by TCD and MRA were investigated. CTA was performed on a Hispeed advantage scanner (GE) using a bolus injection of 70 ml KM and 40 ml NaCl with a flow rate of 2.5 ml/s, a thickness of 1 mm, a pitch of 1.5 and a 1 mm increment. CTA was presented as maximum intensity projection (MIP) and as multi-projection volume reconstruction (MPVR). A three-step classification of stenosis was compared with the results of TCD and MRA. Good opacification of the MCA was achieved in M1 and M2 segments in all patients. Classification of stenosis by CTA agreed with MRA and TCD in 14 cases; 7 stenoses were assigned to a lower classification by CTA. Two lowgrade stenoses could not be proven by CTA. Although MIP and MPVR yield the same result in stenosis classification MPVR showed a sharper image quality. In contrast to MRA, veins were highly opacified in CTA. Artery and vein were sometimes superimposed, which had to be avoided by changing the projection angle. Medium- and high-grade MCA stenoses can be demonstrated by CTA quickly and reliably. Compared to MRA and TCD, CTA provides lower grading of stenosis. (orig.) [de

  8. FungiDB: An Integrated Bioinformatic Resource for Fungi and Oomycetes

    Directory of Open Access Journals (Sweden)

    Evelina Y. Basenko

    2018-03-01

    Full Text Available FungiDB (fungidb.org is a free online resource for data mining and functional genomics analysis for fungal and oomycete species. FungiDB is part of the Eukaryotic Pathogen Genomics Database Resource (EuPathDB, eupathdb.org platform that integrates genomic, transcriptomic, proteomic, and phenotypic datasets, and other types of data for pathogenic and nonpathogenic, free-living and parasitic organisms. FungiDB is one of the largest EuPathDB databases containing nearly 100 genomes obtained from GenBank, Aspergillus Genome Database (AspGD, The Broad Institute, Joint Genome Institute (JGI, Ensembl, and other sources. FungiDB offers a user-friendly web interface with embedded bioinformatics tools that support custom in silico experiments that leverage FungiDB-integrated data. In addition, a Galaxy-based workspace enables users to generate custom pipelines for large-scale data analysis (e.g., RNA-Seq, variant calling, etc.. This review provides an introduction to the FungiDB resources and focuses on available features, tools, and queries and how they can be used to mine data across a diverse range of integrated FungiDB datasets and records.

  9. Protective effects of SGLT2 inhibitor luseogliflozin on pancreatic β-cells in obese type 2 diabetic db/db mice

    Energy Technology Data Exchange (ETDEWEB)

    Okauchi, Seizo, E-mail: okauchi@med.kawasaki-m.ac.jp; Shimoda, Masashi; Obata, Atsushi; Kimura, Tomohiko; Hirukawa, Hidenori; Kohara, Kenji; Mune, Tomoatsu; Kaku, Kohei; Kaneto, Hideaki

    2016-02-12

    It is well known that Sodium-Glucose Co-transporter 2 (SGLT2) inhibitors, new hypoglycemic agents, improve glycemic control by increasing urine glucose excretion, but it remained unclear how they exert protective effects on pancreatic β-cells. In this study, we examined the effects of SGLT2 inhibitor luseogliflozin on β-cell function and mass using obese type 2 diabetic db/db mice. Ten-week-old male diabetic db/db mice were treated with luseogliflozin 0.0025% or 0.01% in chow (Luse 0.0025% or Luse 0.01%) or vehicle (control) for 4 weeks. Urinary glucose excretion was increased in Luse groups (0.0025% and 0.01%) compared to control mice 3 days after the intervention. Fasting blood glucose levels were significantly lower in mice treated with Luse compared to control mice. Fasting serum insulin concentrations were significantly higher in mice treated with Luse compared to control mice. Triglyceride levels tended to be lower in Luse groups compared to control mice. In immunohistochemical study using pancreas tissues, β-cell mass was larger in Luse groups compared to control group which was due to the increase of β-cell proliferation and decrease of β-cell apoptosis. Furthermore, in gene analysis using isolated islets, insulin 1, insulin 2, MafA, PDX-1 and GLUT2 gene expression levels were significantly higher in Luse groups compared to control group. In contrast, expression levels of fibrosis-related gene such as TGFβ, fibronectin, collagen I and collagen III were significantly lower in Luse groups. In conclusion, SGLT2 inhibitor luseogliflozin ameliorates glycemic control and thus exerts protective effects on pancreatic β-cell mass and function. - Highlights: • SGLT2 inhibitor luseogliflozin ameliorates glycemic control in db/db mice. • Luseogliflozin increases β-cell proliferation and decreases β-cell apoptosis. • Luseogliflozin preserves various β-cell-specific gene expression. • Luseogliflozin decreases various fibrosis-related factors in db/db

  10. Protective effects of SGLT2 inhibitor luseogliflozin on pancreatic β-cells in obese type 2 diabetic db/db mice

    International Nuclear Information System (INIS)

    Okauchi, Seizo; Shimoda, Masashi; Obata, Atsushi; Kimura, Tomohiko; Hirukawa, Hidenori; Kohara, Kenji; Mune, Tomoatsu; Kaku, Kohei; Kaneto, Hideaki

    2016-01-01

    It is well known that Sodium-Glucose Co-transporter 2 (SGLT2) inhibitors, new hypoglycemic agents, improve glycemic control by increasing urine glucose excretion, but it remained unclear how they exert protective effects on pancreatic β-cells. In this study, we examined the effects of SGLT2 inhibitor luseogliflozin on β-cell function and mass using obese type 2 diabetic db/db mice. Ten-week-old male diabetic db/db mice were treated with luseogliflozin 0.0025% or 0.01% in chow (Luse 0.0025% or Luse 0.01%) or vehicle (control) for 4 weeks. Urinary glucose excretion was increased in Luse groups (0.0025% and 0.01%) compared to control mice 3 days after the intervention. Fasting blood glucose levels were significantly lower in mice treated with Luse compared to control mice. Fasting serum insulin concentrations were significantly higher in mice treated with Luse compared to control mice. Triglyceride levels tended to be lower in Luse groups compared to control mice. In immunohistochemical study using pancreas tissues, β-cell mass was larger in Luse groups compared to control group which was due to the increase of β-cell proliferation and decrease of β-cell apoptosis. Furthermore, in gene analysis using isolated islets, insulin 1, insulin 2, MafA, PDX-1 and GLUT2 gene expression levels were significantly higher in Luse groups compared to control group. In contrast, expression levels of fibrosis-related gene such as TGFβ, fibronectin, collagen I and collagen III were significantly lower in Luse groups. In conclusion, SGLT2 inhibitor luseogliflozin ameliorates glycemic control and thus exerts protective effects on pancreatic β-cell mass and function. - Highlights: • SGLT2 inhibitor luseogliflozin ameliorates glycemic control in db/db mice. • Luseogliflozin increases β-cell proliferation and decreases β-cell apoptosis. • Luseogliflozin preserves various β-cell-specific gene expression. • Luseogliflozin decreases various fibrosis-related factors in db/db

  11. Intra-arterial digital subtraction angiography (IA-DSA) with carbon dioxide

    International Nuclear Information System (INIS)

    Takeda, Toshiaki; Ido, Kunio; Yuasa, Yuji

    1988-01-01

    Intra-Arterial Digital Subtraction Angiography (IA-DSA) with Carbon Dioxide (CO 2 ) was performed on 41 patients mainly with liver or renal diseases, and its angiographic manifestation was compared with that of conventional angiography. Although the image quality of the arterial or capillary phase was inferior to that of conventional angiography with iodinated contrast media, the detectablity of arterio-venous shunting was excellent. In fact, DSA with CO 2 revealed the presence of A-V (A-P) shunt in 26 patients (26/41:63.4 % HCC, 13/15:86.7% metastatic liver tumor, 2/3:66.7 % RCC, 1/5:20 %). On the other hand, conventional angiography was able to show in only 5 cases. DSA with CO 2 will become an effective method for detecting minute arterio-venous shunting which can not be demonstrated with conventional angiography. (author)

  12. Comparison between angiography and CT scan in the urologic field

    Energy Technology Data Exchange (ETDEWEB)

    Fujioka, Toshio; Takao, Masaya; Odajima, Kunio; Nakamura, Hiroshi

    1988-02-01

    Seventy-five consecutive patients with urological diseases were examined preoperatively by means of computerized tomography and renal angiography. Classification of the diseases were 53 renal diseases which included renal cell carcinoma, sarcoma, cyst, renal bleeding, arteriovenous fistula, trauma, hydronephrosis and tuberculosis, 11 vesical diseases which included bladder tumor and endometriosis, 9 adrenal diseases which included primary aldosteronism, Cushing syndrome, pheochromocytoma, and metastatic tumor, and 1 case of intra-abdominal testes. For renal diseases, both angiography and CT were useful imaging tools. For vesical diseases, CT was a more useful imaging method but, for adrenal diseases, angiography was superior to CT. CT offers certain advantages over conventional techniques but, in the near future, it may be replaced by MRI. On the contrary, angiography will remain popular for a long time, because angiography is the only way to show which vessels feed organs.

  13. The Role of Intraoperative Cerebral Angiography in Transorbital Intracranial Penetrating Trauma: A Case Report and Literature Review.

    Science.gov (United States)

    Riley, Jonathan P; Boucher, Andrew B; Kim, Denise S; Barrow, Daniel L; Reynolds, Matthew R

    2017-01-01

    Transorbital intracranial penetrating trauma with a retained intracranial foreign body is a rare event lacking a widely accepted diagnostic and therapeutic algorithm. Intraoperative catheter angiography (IOA) has been advocated by some authorities to rule out cerebrovascular injury before and/or after removal of the object, but no standard of care currently exists. A 19-year-old man was involved in a construction site accident whereby a framing nail penetrated the left globe, traversed the lateral bony orbit, and terminated in the midtemporal lobe. No hematoma or injury to the middle cerebral arteries (MCAs) was apparent on noncontrast head computed tomography (CT) or CT angiography, respectively. The foreign body was removed in the operating room under direct visualization after a frontotemporal craniotomy without incident. No significant venous or arterial bleeding was encountered. All visualized MCA branches appeared intact. Indocyanine green videoangiography performed immediately after object removal showed adequate filling of the MCA branches. Given these uneventful clinical and radiographic findings, IOA was not performed. Postoperative head CT and CT angiography showed no obvious neurovascular injury. On postoperative day 2, the patient was noted to have an expressive aphasia. Cerebral angiography showed absent antegrade filling of the angular artery with some retrograde perfusion. Magnetic resonance imaging confirmed an ischemic infarction in the midtemporal lobe. The patient's expressive aphasia improved to near baseline during his hospitalization and he made an excellent clinical recovery. In transorbital intracranial penetrating trauma with a retained intracranial object, we advocate microsurgical removal of the object under direct visualization followed immediately by IOA. IOA should be strongly considered even in the setting of minimal intraoperative bleeding and normal findings on videoangiography (a course of action that was not followed in the

  14. Incidence and predictors of silent embolic cerebral infarction following diagnostic coronary angiography.

    Science.gov (United States)

    Kim, In-Cheol; Hur, Seung-Ho; Park, Nam-Hee; Jun, Dong-Hwan; Cho, Yun-Kyeong; Nam, Chang-Wook; Kim, Hyungseop; Han, Seong-Wook; Choi, Sae-Young; Kim, Yoon-Nyun; Kim, Kwon-Bae

    2011-04-14

    Coronary angiography (CAG) is an invasive diagnostic procedure, which could lead to procedure related complications. One of the well known post-procedural complications is cerebral embolic infarction with or without symptoms. Silent embolic cerebral infarction (SECI) has clinical significance because it can progress to a decline in cognitive function and increase the risk of dementia in the long term. The aim of this study was to detect the incidence and predictors of SECI after diagnostic CAG using diffusion-weighted magnetic resonance imaging (DW-MRI). A total of 197 patients with coronary artery disease who underwent DW-MRI for evaluation of intracranial vasculopathy before coronary artery bypass graft surgery were retrospectively enrolled in the present study. DW-MRI was performed within 48 h after diagnostic CAG. SECI was diagnosed as presence of focal bright high signal intensity in DW-MRI. Patients were divided into groups according to presence/absence of SECI (+ SECI vs. - SECI, respectively). The clinical and angiographic characteristics were analyzed and independent predictors were evaluated. Of the 197 patients, SECI occurred in 20 patients (10.2%) after diagnostic CAG. Age, female gender, frequency of underlying atrial fibrillation, extent of coronary disease, and fluoroscopic time during diagnostic CAG were not different between the + SECI and - SECI groups. Left ventricular ejection fraction was significantly lower in the + SECI group than in the - SECI group (45.9 ± 8.5% vs. 51.4 ± 13.1%, p=0.014) and performance rate of internal mammary artery (IMA) angiography was significantly higher in the + SECI group compared with the - SECI group (85% vs. 37.2%, pSECI (OR=14.642; 95% CI=3.201 to 66.980, p=0.001). The incidence of SECI after diagnostic CAG was not infrequent. Diagnostic CAG with IMA angiography may increase the risk of SECI. Copyright © 2009 Elsevier Ireland Ltd. All rights reserved.

  15. Magnetic resonance imaging of the coronary arteries : clinical results from three dimensional evaluation of a respiratory gated technique

    NARCIS (Netherlands)

    van Geuns, R J; de Bruin, H G; Rensing, B J; Wielopolski, P A; Hulshoff, M D; van Ooijen, P M; Oudkerk, M; de Feyter, P J

    1999-01-01

    BACKGROUND: Magnetic resonance coronary angiography is challenging because of the motion of the vessels during cardiac contraction and respiration. Additional challenges are the small calibre of the arteries and their complex three dimensional course. Respiratory gating, turboflash acquisition, and

  16. Spiral CT angiography of renal arteries: comparison with angiography

    International Nuclear Information System (INIS)

    Wittenberg, G.; Kenn, W.; Tschammler, A.; Sandstede, J.; Hahn, D.

    1999-01-01

    A prospective study was carried out to determine the accuracy of spiral CT angiography (CTA) in the detection of renal artery stenosis (RAS). Eighty-two patients with arterial hypertension underwent CTA and digital subtraction angiography (DSA) to exclude RAS. For CTA a contrast medium bolus of 100-150 ml (flow rate 3 ml/s) was injected. A 24 or 40 s CTA was started at the origin of the superior mesenteric artery after a delay time determined by test bolus injection (collimation = 2 mm, pitch = 1/1.5). For stenosis detection transverse images supported by maximum intensity projections (MIP) or multiplanar reconstruction projections were used. Of 197 renal arteries examined (including 33 accessory arteries), 34 RAS were visualized using DSA. With CTA, one hemodynamic RAS was missed and one additional hemodynamic RAS was found. Sensitivity/specificity was calculated to be 94 %/98 %. For hemodynamically relevant RAS (> 50 %) the sensitivity/specificity was 96 %/99 %. CTA additionally depicted five adrenal masses. The high accuracy rate of RAS detection thus allows the use of CTA as a screening method in patients with arterial hypertension to exclude a renovascular cause. (orig.)

  17. Access of vehicles to DB netz infrastructure; Zugang von Fahrzeugen zur DB-Netz-Infrastruktur

    Energy Technology Data Exchange (ETDEWEB)

    Resch, U. [DB Systemtechnik, Frankfurt am Main (Germany); Ruch, M. [DB Energie GmbH, Frankfurt am Main (Germany)

    2003-05-01

    For line access it is necessary to take into account and observe the requirements of the infrastructure. The requirements and certifications for the power supply system and pantograph-overhead contact line interaction are described in the DB guidelines 810.0241 and 810.0242. (orig.) [German] Fuer den Netzzugang muessen die Anforderungen der Infrastruktur beachtet und eingehalten werden. Die Anforderungen und die erforderlichen Nachweise fuer den Bereich Energieversorgung und Zusammenwirken von Stromabnehmer und Oberleitung sind in den Richtlinien 810.0241 und 810.0242 der DB enthalten. (orig.)

  18. Time-resolved magnetic resonance angiography (MRA) at 3.0 Tesla for evaluation of hemodynamic characteristics of vascular malformations: description of distinct subgroups

    Energy Technology Data Exchange (ETDEWEB)

    Hammer, Simone; Fellner, Claudia; Wohlgemuth, Walter A. [University Hospital Regensburg, Department of Radiology, Regensburg (Germany); Uller, Wibke [Boston Children' s Hospital and Harvard Medical School, Division of Vascular and Interventional Radiology, Boston, MA (United States); University Hospital Regensburg, Department of Radiology, Regensburg (Germany); Manger, Florentine [University Hospital Wuerzburg, Department of Nuclear Medicine, Wuerzburg (Germany); Zeman, Florian [University Hospital Regensburg, Center for Clinical Trials, Regensburg (Germany)

    2017-01-15

    Quantitative evaluation of hemodynamic characteristics of arteriovenous and venous malformations using time-resolved magnetic resonance angiography (MRA) at 3.0 Tesla. Time-resolved MRA with interleaved stochastic trajectories (TWIST) at 3.0 Tesla was studied in 83 consecutive patients with venous malformations (VM) and arteriovenous malformations (AVM). Enhancement characteristics were calculated as percentage increase of signal intensity above baseline over time. Maximum percentage signal intensity increase (signal{sub max}), time intervals between onset of arterial enhancement and lesion enhancement (t{sub onset}), and time intervals between beginning of lesion enhancement and maximum percentage of lesion enhancement (t{sub max}) were analyzed. All AVMs showed a high-flow hemodynamic pattern. Two significantly different (p < 0.001) types of venous malformations emerged: VMs with arteriovenous fistulas (AVF) (median signal{sub max} 737 %, IQR [interquartile range] = 511 - 1182 %; median t{sub onset} 5 s, IQR = 5 - 10 s; median t{sub max} 35 s, IQR = 26 - 40 s) and without AVFs (median signal{sub max} 284 %, IQR = 177-432 %; median t{sub onset} 23 s, IQR = 15 - 30 s; median t{sub max} 60 s, IQR = 55 - 75 s). Quantitative evaluation of time-resolved MRA at 3.0 Tesla provides hemodynamic characterization of vascular malformations. VMs can be subclassified into two hemodynamic subgroups due to presence or absence of AVFs. (orig.)

  19. Angiography in tumors of cartilaginous genesis

    International Nuclear Information System (INIS)

    Korolev, V.I.

    1986-01-01

    Angiography was used for 122 patients with tumors and tumor-like processes of the cartilage. Angiography was carried out by the S. Seldinger method. Normal angioarchitecture was observed in 16 patients with benign tumors (20 patients), characters of malignant tumor are determined in 4 patients. Normal angioarchitecture is determined in 9.4% of patients with chondrosarcoma (102 patients). The examination carried out showed that angiographic symptotics in chondrosarcomas varied depending on the stage, localization and the degree of morphologic differentiation

  20. Compact Dual-Band Bandpass Filter Using Stubs Loaded Ring Resonator

    Science.gov (United States)

    Xu, Jin

    2016-01-01

    This paper presents a novel second-order dual-band bandpass filter (BPF) by using proposed stubs loaded ring resonator. The resonant behavior of proposed stubs loaded ring resonator is analyzed by even-/odd-mode method, which shows its multiple-mode resonant characteristic. Parameters sweep is done so as to give the design guidelines. As an example, a second-order dual-band BPF operating at 1.8/5.2 GHz for GSM and WLAN applications is designed, fabricated and measured. The fabricated filter has a very compact size of 0.05λg×0.15λg. Measured results also show that the proposed dual-band BPF has a better than 20 dB rejection upper stopband from 5.47 GHz to 12.56 GHz. Good agreement is shown between the simulated and measured results.