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Sample records for angiography intrakranielle mr-angiographie

  1. MR angiography

    International Nuclear Information System (INIS)

    Masaryk, T.J.; Ross, J.S.

    1991-01-01

    This paper reports on preliminary research and recent clinical experience which indicates that MR angiography can play a role in routine scanning by providing useful information regarding the anatomy of the cerebral circulation. Used in conjunction with conventional spin-echo studies it may improve the overall sensitivity and specificity of MRI in a cost-effective fashion. It does not, however, replace conventional arteriography at this time for either extracranial or intracranial disease. The use of intravascular contrast agents with new fast-scan techniques also provides dynamic information regarding tissue perfusion in a fashion analogous to that of xenon CT. While this work is preliminary, and the exact agents and mathematical models have yet to be defined, the ability to perform parenchymal, angiographic, and physiologic imaging at a single setting is potentially very powerful. Clearly, the role of MR flow techniques deserves further investigation into possible technical refinements, so that accuracy relative to other diagnostic studies and impact upon patient management can be assessed in a meaningful way

  2. 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

  3. 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

  4. MR angiography with Vasovist

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    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.

  5. 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

  6. Nonenhanced MR angiography techniques

    International Nuclear Information System (INIS)

    Lanzman, R.S.; Kroepil, P.; Blondin, D.; Schmitt, P.

    2011-01-01

    Especially in regard to the potential risks for the development of nephrogenic systemic fibrosis (NSF) following the administration of Gadolinium-based contrast material, nonenhanced MR angiography (MRA) methods are becoming ever more important. Besides well-established time-of-flight (TOF) and phase-contrast (PC) MRA, alternative imaging techniques based on balanced steady-state free precession (bSSFP) and turbo-spin-echo (TSE) sequences are increasingly used in combination with or without arterial spin labeling (ASL) strategies. This article provides an overview of the principles and clinical values of different nonenhanced MRA techniques. In addition, recent nonenhanced MRA developments are presented. (orig.)

  7. 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

  8. MR angiography (MRA)

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    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).

  9. 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.)

  10. Vasovist-enhanced MR angiography

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    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.)

  11. Electrocardiographically gated snapshot MR angiography

    International Nuclear Information System (INIS)

    Brown, D.G.; Holsinger, A.E.; Riederer, S.J.

    1990-01-01

    The purpose of this paper is to evaluate the effectiveness of applying ultrashort (∼12 msec) TR times and measuring the central phase encodings first in improving the accuracy of vascular depiction in MR angiography. The imaging method combines ultrashort TR imaging techniques with time-of-flight MR angiography. The central phase-encoding views are acquired first, and an inversion-recovery contrast preparation pulse is applied prior to image acquisition to null signal from static tissues. In initial studies, the method was tested on phantoms and volunteers. The contrast-preparation phase effectively nulls static spins at the start of image acquisition. During the TL period fresh blood flows into the imaging section; even slowly moving blood is fully replaced

  12. Contrast-enhanced MR angiography

    International Nuclear Information System (INIS)

    Bosmans, H.; Marchal, G.

    1996-01-01

    Despite many optimizations, the current limitations of plain MR angiography include: Saturation that impairs the visualization of veins and arteries with slow flow and spin-dephasing signal voids in locations with turbulent flow. Recently, the use of contrast agents has been proposed to cope with these remaining problems. Because of induced shortening of the T1 of the blood, saturation in the blood vessels is overcome. As a result, arteries and veins are visualized with the same signal intensity, which makes the technique less flow-dependent. In combination with short T1-weighted acquisitions, today CE MRA can be obtained while the patient is holding his breath. This last approach is most promising for abdominal applications since the respiratory motion can be frozen. As these acquisitions also use very short echo times, spin dephasing can be reduced. In conclusion, the use of contrast agents has greatly increased the clinical usefulness of MR angiography. (orig.) [de

  13. 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

  14. Rapid line scan MR angiography

    International Nuclear Information System (INIS)

    Frahm, J.; Merboldt, K.D.; Hanicke, W.; Bruhn, H.

    1987-01-01

    Direct MR angiography may be performed using line scan imaging techniques combined with presaturation of stationary spins. Thus, a single line scan echo yields a projection of vessels due to the signal from reflowing unsaturated spins. Reconstruction of an angiographic image is performed line by line at slightly incremented positions. In particular, line scan angiography is direct and fast without a sensitivity to artifacts even for high flow rates. Image resolution and field of view may be chosen without restrictions, and zoom images using enhanced gradients may be recorded without aliasing artifacts. The method is robust with respect to eddy currents and pulsatile flow. Line scan MR angiograms of phantoms, animals, and human volunteers have been recorded using 90 0 radio frequency pulses and gradient-recalled echoes

  15. MR angiography in tuberculous meningitis

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    Kalita, Jayantee; Prasad, Sreeram; Maurya, Pradeep K.; Misra, Usha K. (Dept. of Neurology, Sanjay Gandhi Post Graduate Inst. of Medical Sciences, Lucknow (India)), Email: drukmisra@rediffmail.com; Kumar, Sunil (Dept. of Radiodiagnosis, Sanjay Gandhi Post Graduate Inst. of Medical Sciences, Lucknow (India))

    2012-04-15

    Background: Infarctions in tuberculous meningitis (TBM) are common but there is a paucity of studies on MR angiography (MRA). Purpose: To evaluate the pattern and predictors of MRA abnormality in patients with TBM. Material and Methods: Sixty-seven patients with TBM were subjected to clinical, laboratory, magnetic resonance imaging (MRI), and MRA evaluation. The severity of meningitis, focal deficit, CSF findings, and stroke co-morbidities were recorded. Presence of exudates, infarction, hydrocephalous, and tuberculoma on MRI were noted. On intracranial MRA, occlusion or more than 50% narrowing of proximal middle cerebral artery (MCA), anterior cerebral artery (ACA) and posterior cerebral artery (PCA), and basilar artery were considered abnormal. The MRA abnormality was correlated with clinical, laboratory, and MRI findings. Results: Sixty-seven patients, aged 3-75 years (median 34 years) were included. MRI was abnormal in 61 (91%) patients; basal exudates in 24, hydrocephalous in 23, tuberculoma in 33, and infarction in 40. MRA was abnormal in 34 (50.7%); MCA was most commonly involved (n = 21), followed by PCA (n = 14), ICA (n = 8), ACA (n 5), basilar artery (n = 5), and vertebral and superior cerebellar artery (1 each). One-fourth of the patients had abnormality in both anterior and posterior circulations. MRA abnormality was related to hydrocephalous and infarction; corresponding infarct was present in 61.8% patients; 41.7% patients with abnormal MRA developed infarct at 3 months but none with normal MRA. Conclusion: Half the patients with TBM had MRA abnormality involving both anterior and posterior circulations and 61.8% of them had corresponding infarcts

  16. MR angiography of cerebral aneurysms

    International Nuclear Information System (INIS)

    Miki, Hitoshi; Tanada, Shuji; Sakaki, Saburo; Hamamoto, Ken; Sadamoto, Kazuhiko.

    1992-01-01

    Time-of-flight (TOF) MR angiography (MRA) and phase-contrast (PC) MRA are examined clinically for evaluating cerebral aneurysms. In the morphological diagnosis of cerebral aneurysms, three-dimensional (3D) MRA is superior to two-dimensional (2D) MRA because 3D MRA has a higher S/N ratio and a higher spatial resolution. However, it is difficult to decide which, 3D TOF MRA or 3D PC MRA, is superior, for both methods have many scan parameters. In our study, 3D PC MRA was performed using two methods; one had the same acquisition time as 3D TOF MRA, while the other had the same spatial resolution as 3D TOF MRA. The detectability of aneurysms by each MRA method was evaluated in comparison with 3D TOF MRA. In fifteen patients (6 males and 9 females), a total of 16 cerebral aneurysms (3 ruptured and 13 unruptured) were studied. The lesion sizes ranged from 2.5 to 18 mm. All the 16 lesions were examined by means of 3D TOF MRA, 3D PC MRA, and conventional angiography. MR imaging was performed with a 1.5 tesla MRI system (Signa). All of the 16 cerebral aneurysms were detected by 3D TOF MRA, while only 11 of them were detected by 3D PC MRA. When 3D PC MRA was performed with the same acquisition time as 3D TOF MRA, 3D PC MRA was superior in showing one of the 7 aneurysms. When 3D PC MRA was performed with same spatial resolution as 3D TOF MRA, 3D PC MRA was superior in showing two of the 10 aneurysms. 3D TOF MRA was superior to 3D PC MRA in the detection of cerebral aneurysms because of the long acquisition times and the different flow velocity, which induced different signal intensities between the aneurysms and parent arteries in 3D PC MRA. 3D PC MRA was superior to 3D TOF MRA in patients with large thrombotic aneurysms of the internal carotid artery. We consider that 3D TOF MRA should be the first choice for screening and following-up cerebral aneurysms. 3D PC MRA should then be performed for large cerebral aneurysms in addition to 3D TOF MRA. (author)

  17. 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.)

  18. Usefulness of MR angiography in renal tumor

    International Nuclear Information System (INIS)

    Oka, Toshitsugu; Morimoto, Kouji; Nishimura, Kenji; Tsujimura, Akira; Yasunaga, Yutaka; Matsumiya, Kiyomi; Takaha, Minato

    1992-01-01

    MR angiography using a gradient-echo, pulse sequence FLASH (fast, low-angle shot) method during breath-hold with a 'MAGNETOM H-15' scanner (1.5 Tesla; Siemens Medical System) was performed on 27 patients with renal tumor at our clinic between Feburary 20, 1990 and September 30, 1991 and we studied to evaluate its usefulness. Of these 27 patients, 22 patients including one patient under hemodialysis treatment had renal cell carcinoma and one patient had oncocytoma pathologically proven from the excised specimens. The remaining four patients including two patients associated with inferior vena cava tumor thrombus were clinically diagnosed as renal cell carcinoma based on the result of imaging examinations such as excretory urography, ultrasonography, computed tomography and conventional angiography. However, they could not be operated on because their tumors were too advanced. By reconstruction of the data of consecutive coronal scans of the abdominal blood vessels such as the abdominal aorta, inferior vena cava and renal arteries and veins simultaneously without any intravenous contrast materials. Our present study revealed that MR angiography has some advantages, especially with regard to preoperative angiographic information about the abdomen of patients with renal tumor. That is, MR angiography can delineate many kinds of arteries and veins of the abdomen simultaneously and in a broader range, as well as it can be performed on the patients with hypersensitivity to iodinate contrast materials or renal insufficiency in a usual fashion. Furthermore, our present study suggested that the MR angiography is useful for assessing the presence and extent of inferior vena caval tumor thrombus of renal cell carcinoma and for clearly distinguishing tumor lesion and the surrounding normal renal parenchyma in the patients with renal tumor. (author)

  19. Usefulness of MR angiography in renal tumor

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    Oka, Toshitsugu; Morimoto, Kouji; Nishimura, Kenji; Tsujimura, Akira; Yasunaga, Yutaka; Matsumiya, Kiyomi; Takaha, Minato (Osaka National Hospital (Japan))

    1992-11-01

    MR angiography using a gradient-echo, pulse sequence FLASH (fast, low-angle shot) method during breath-hold with a MAGNETOM H-15 scanner (1.5 Tesla; Siemens Medical System) was performed on 27 patients with renal tumor at our clinic between Feburary 20, 1990 and September 30, 1991 and we studied to evaluate its usefulness. Of these 27 patients, 22 patients including one patient under hemodialysis treatment had renal cell carcinoma and one patient had oncocytoma pathologically proven from the excised specimens. The remaining four patients including two patients associated with inferior vena cava tumor thrombus were clinically diagnosed as renal cell carcinoma based on the result of imaging examinations such as excretory urography, ultrasonography, computed tomography and conventional angiography. However, they could not be operated on because their tumors were too advanced. By reconstruction of the data of consecutive coronal scans of the abdominal blood vessels such as the abdominal aorta, inferior vena cava and renal arteries and veins simultaneously without any intravenous contrast materials. Our present study revealed that MR angiography has some advantages, especially with regard to preoperative angiographic information about the abdomen of patients with renal tumor. That is, MR angiography can delineate many kinds of arteries and veins of the abdomen simultaneously and in a broader range, as well as it can be performed on the patients with hypersensitivity to iodinate contrast materials or renal insufficiency in a usual fashion. Furthermore, our present study suggested that the MR angiography is useful for assessing the presence and extent of inferior vena caval tumor thrombus of renal cell carcinoma and for clearly distinguishing tumor lesion and the surrounding normal renal parenchyma in the patients with renal tumor. (author).

  20. 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

  1. Striatocapsular infarction: MRI and MR angiography

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    Croisille, P. (Dept. of Neuroradiology, Hopital Neurologique et Neurochirurgical Pierre Wertheimer, Lyon (France)); Turjman, F. (Dept. of Neuroradiology, Hopital Neurologique et Neurochirurgical Pierre Wertheimer, Lyon (France)); Croisile, B. (Dept. of Neurology, Hopital Neurologique et Neurochirurgical Pierre Wertheimer, Lyon (France)); Tournut, P. (Dept. of Neuroradiology, Hopital Neurologique et Neurochirurgical Pierre Wertheimer, Lyon (France)); Laharotte, J.C. (Dept. of Neuroradiology, Hopital Neurologique et Neurochirurgical Pierre Wertheimer, Lyon (France)); Aimard, G. (Dept. of Neurology, Hopital Neurologique et Neurochirurgical Pierre Wertheimer, Lyon (France)); Trillet, M. (Dept. of Neurology, Hopital Neurologique et Neurochirurgical Pierre Wertheimer, Lyon (France)); Duquesnel, J. (Dept. of Neuroradiology, Hopital Neurologique et Neurochirurgical Pierre Wertheimer, Lyon (France)); Froment, J.C. (Dept. of Neuroradiology, Hopital Neurologique et Neurochirurgical Pierre

    1994-08-01

    We present a case of left striatocapsular infarction manifest clinically as a transient right hemiparesis. MRI showed a left striatocapsular infarct. Striatocapsular infarction, unlike lacunar infarction, is often associated with occlusive disease of the carotid artery. In order to screen the carotid vessels, cervical MR angiography (MRA) was performed during the same examination, demonstrating a left internal carotid artery occlusion, confirmed by contrast arteriography. MRA, a noninvasive modality, can be a useful adjunct to MRI, when diagnostic information concerning the cervical carotid artery is needed. (orig.)

  2. 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

  3. Value of MR-angiography in brain infarction

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    Pirronello, Veronica; Capizzano, Aristides A.; Chouela, Carolina L.; Ternak, Alejandro; Ramirez, Susana; Mazzuco, Juan C.

    2004-01-01

    A retrospective study has been performed in a series of 237 patients, with brain and neck MR and MR angiography techniques. 108/237 (45.5%) patients presented either hemorrhage or lacunar and non lacunar ischemic stroke, 67 of which showed restricted diffusion. Diffusion and perfusion techniques can significantly contribute to study acute stroke. In our series MR angiography showed a 4% sensitivity to detect small arteries pathology. (author)

  4. 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)

  5. Clinical application of pelvic MR angiography for gynecologic diseases

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    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)

  6. 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)

  7. 2D MR angiography of the aortic aneurysm

    International Nuclear Information System (INIS)

    Amanuma, Makoto; Hasegawa, Makoto; Watabe, Tsuneya; Heshiki, Atsuko

    1992-01-01

    2D time-of-flight MR angiography was performed in 6 cases of thoracic aortic aneurysm. Oblique saturation pulses were used to suppress the signals of the pulmonary artery and SVC, providing excellent selective MR aortograms. Three dimensional extension of the aneurysm and its relation with cervical branches were easily assessed. It could be possible to replace invasive aortography by this technique. (author)

  8. 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.)

  9. MR angiography of in situ and transplanted renal arteries

    International Nuclear Information System (INIS)

    Smith, H.J.; Bakke, S.J.

    1993-01-01

    Three-dimensional (3D) time-of-flight (TOF) MR angiography (MRA) was performed in 34 patients with suspected renal artery disease. In situ (i.e., nontransplanted) renal arteries were studied with MRA in 14 patients. Of these, 12 had conventional angiography for comparison. Twenty-four MRAs of transplanted renal arteries were obtained in 20 patients; 8 of these had angiography as well. Significant stenoses of in situ renal arteries were diagnosed with a sensitivity of 100% and a specificity of 95%. The stenoses were all proximal; 3D TOF MRA proved inadequate for depiction of peripheral renal arteries. MRA and angiography showed good agreement between findings in 7 of 8 patients with renal transplants. In one patient with a renal transplant, MRA showed a significant stenosis of the arterial anastomosis which appeared completely normal at i.a. DSA, indicating that findings at MRA still need to be confirmed by more established alternative methods. (orig.)

  10. 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

  11. Gadolinium-enhanced MR angiography of the thoracoabdominal aorta diseases

    International Nuclear Information System (INIS)

    D'Ippolito, Giuseppe; Wolosker, Nelson; Galvao Filho, Mario; Kalil, Jorge A.; Wolosker, Angela; Borri, Maria Lucia

    1998-01-01

    Gadolinium-enhanced MR angiography (GEMRA) of the thoracoabdominal aorta is a noninvasive technique that can rapidly delineate the branch vessels diseases, without flow or respiration artifacts, obtained with non contrast MRA. The objective of this paper is to show the main clinical applications of GEMRA, compared to non contrast sequences. We have evaluated 30 patients with thorocoabdominal aorta diseases. These patients have been examined with GEMRA (3D, FFE sequences) obtained after 30 mlIV contrast injection and non contrast MRA (2D-TOF sequences). In our experience, gadolinium-enhanced MRA is a high resolution and speedy technique with advantages over non contrast MRA. (author)

  12. MRI and MR angiography of persistent trigeminal artery

    International Nuclear Information System (INIS)

    Piotin, M.; Miralbes, S.; Cattin, F.; Marchal, H.; Amor-Sahli, M.; Moulin, T.; Bonneville, J.F.

    1996-01-01

    We describe the MRA and MR angiography (MRA) features of persistent trigeminal artery (PTA) found incidentally in eight patients, with special attention to its origin, site and course. The different patterns of posterior communicating arteries were also noted. The PTA were shown on sagittal, coronal and axial MRI and on MRA. In four cases, the PTA arose from the lateral aspect of the intracavernous internal carotid artery, ran caudally, passing round the bottom of the dorsum sellae to join the basilar artery. In the other four cases, it arose from the medial aspect, ran caudally through the sella turcica and pierced the dorsum sellae to join the basilar artery. The posterior communicating arteries were present unilaterally in five cases and bilaterally in one, and absent bilaterally in two. Identification of a PTA with a trans-sellar course is crucial if a trans-sphenoidal surgery is planned. (orig.). With 3 figs

  13. Usefulness of MR angiography in cases of central vertigo.

    Science.gov (United States)

    Fujita, Nobuya; Yamanaka, Toshiaki; Hosoi, Hiroshi

    2002-07-01

    Syndromal vertigo is defined as a combination of vestibular function disturbance and cranial nerve or cerebral function disturbance. There is evidence that MR angiography (MRA), providing angiogram-like images of the intracranial and extracranial arterial flow, could replace invasive methods for diagnosing central vertigo. The purpose of this study was to provide simplified MRA criteria for identifying morbidity and to analyze the relation between imaging findings and clinical manifestations. Thirty-three individuals with symptoms of syndromal vertigo and vertebrobasilar territory disease were examined by equilibriometry, MR imaging (MRI) and MRA. Under MRA, vertebral artery (VA) stenosis was more common than VA occlusion (23 vs. nine cases, respectively). A basilar artery (BA) deviation was found in eight cases (24.2%). Twenty-five VA or BA abnormalities (75.8%) were found, and eight combined VA and BA abnormalities (24.2%) were found. We emphasize three points as follows. MRA is advantageous over conventional angiography for less invasive method. MRA can reveal abnormalities even in cases of 'solo-vertigo' with no observed neurologic abnormalities. In our series, abnormalities were confirmed by MRA even in cases with no concomitant such as hypertension, coronary heart disease, or diabetes mellitus, which are regarded as latent risk factors for stroke.

  14. Prevalence of Unruptured Intracranial Aneurysm on MR Angiography

    International Nuclear Information System (INIS)

    Jeon, Tae Yeon; Jeon, Pyoung; Kim, Keon Ha

    2011-01-01

    To evaluate the prevalence of incidentally found unruptured intracranial aneurysms (UIAs) on the brain MR angiography (MRA) from a community-based general hospital. This was a prospectively collected retrospective study, carried out from January 2004 to December 2004. The subjects included 3049 persons from a community-based hospital in whom MRA was performed according to a standardized protocol in an outpatient setting. Age- and sex-specific prevalence of UIAs was calculated. The results by MRA were compared with intra-arterial digital subtraction angiography (DSA) findings. Unruptured intracranial aneurysms were found in 137 (5%) of the 3049 patients (M:F 43:94; mean age, 60.2 years). The prevalence of UIAs was 5% (n = 94) in women and 4% (n = 43) in men, respectively (p = 0.2046) and showed no age-related increase. The most common site of aneurysm was at the distal internal carotid artery (n = 64, 39%), followed by the middle cerebral artery (n = 40, 24%). In total, 99% of aneurysms measured less than 12 mm, and 93% of aneurysms measured less than 7 mm. Direct comparisons between MRA and DSA were available in 70 patients with 83 UIAs; the results revealed two false positive and two false negative results. This community-hospital based study suggested a higher prevalence of UIAs observed by MRA than previously reported. These findings should be anticipated in the design and use of neuroimaging in clinical practice.

  15. Evaluation of diagnostic accuracy of cerebral aneurysms on MR angiography

    International Nuclear Information System (INIS)

    Miki, Hitoshi

    1996-01-01

    The purpose of this study was to evaluate the diagnostic accuracy of MR angiography (MRA) for detection of intracranial aneurysms (IAs) by prospective and retrospective examinations. The detection rates for MRA were: 3D time-of-flight (TOF), 94.2% (n=69); 3D phase contrast (PC), 75% (n=20); 2D TOF, 68% (n=25); and 2D PC, 59.4% (n=32). In aneurysms smaller than 5-mm, the detection rates were: 3D TOF, 87.9% (n=33); 3D PC, 42.9% (n=7); 2D TOF, 0% (n=8); and 2D PC, 14.3% (n=14). In the detection of IAs smaller than 5-mm, 3D TOF was superior to other MRA methods. Four IAs could not be detected by 3D TOF with a standard voxel size. These four IAs smaller than 3-mm were detected by 3D TOF with a small voxel size. In the blinded examination, the detection rate of IAs using MIP images was 71.8%, however, it using MIP and source images was 93.5%. False positive cases were reduced by using source images. In prospective study including 200 cases, IAs smaller than 5-mm were detected in 12 individuals underwent conventional angiography or CT angiography. Seven of them were true positive, however, 5 smaller than 2-mm on MRA were false positive. In conclusions, IAs 3-mm or larger can be identified by 3D TOF MRA with a small voxel size; however, IAs smaller than 2-mm on MRA are difficult to detect without false positive. (author)

  16. Phase-contrast MR angiography of intracranial dural arteriovenous fistulae

    International Nuclear Information System (INIS)

    Cellerini, M.; Mascalchi, M.; Mangiafico, S.; Ferrito, G.P.; Scardigli, V.; Pellicano, G.; Quilici, N.

    1999-01-01

    MRI and phase-contrast MR angiography (PC MRA) were obtained in 13 patients with angiographically confirmed intracranial dural arteriovenous fistulae (DAVF). Three- and two-dimensional PC MRA was obtained with low (6-20 cm/s) and high (>40 cm/s) velocity encoding along the three main body axes. MRI showed focal or diffuse signal abnormalities in the brain parenchyma in six patients, dilated cortical veins in seven, venous pouches in four with type IV DAVF and enlargement of the superior ophthalmic vein in three patients with DAVF of the cavernous sinus. However, it showed none of the fistula sites and did not allow reliable identification of feeding arteries. 3D PC MRA enabled identification of the fistula and enlarged feeding arteries in six cases each. Stenosis or occlusion of the dural sinuses was detected in six of eight cases on 3D PC MRA with low velocity encoding. In six patients with type II DAVF phase reconstruction of 2D PC MRA demonstrated flow reversal in the dural sinuses or superior ophthalmic vein. (orig.)

  17. Maximum intensity projection MR angiography using shifted image data

    International Nuclear Information System (INIS)

    Machida, Yoshio; Ichinose, Nobuyasu; Hatanaka, Masahiko; Goro, Takehiko; Kitake, Shinichi; Hatta, Junicchi.

    1992-01-01

    The quality of MR angiograms has been significantly improved in past several years. Spatial resolution, however, is not sufficient for clinical use. On the other hand, MR image data can be filled at anywhere using Fourier shift theorem, and the quality of multi-planar reformed image has been reported to be improved remarkably using 'shifted data'. In this paper, we have clarified the efficiency of 'shifted data' for maximum intensity projection MR angiography. Our experimental studies and theoretical consideration showd that the quality of MR angiograms has been significantly improved using 'shifted data' as follows; 1) remarkable reduction of mosaic artifact, 2) improvement of spatial continuity for the blood vessels, and 3) reduction of variance for the signal intensity along the blood vessels. In other words, the angiograms looks much 'finer' than conventional ones, although the spatial resolution is not improved theoretically. Furthermore, we found the quality of MR angiograms dose not improve significantly with the 'shifted data' more than twice as dense as ordinal ones. (author)

  18. Preoperative MR angiography evaluation of transjugular intrahepatic portosystemic shunt

    International Nuclear Information System (INIS)

    Guo Li; Yang Dakuan; Yuan Shuguang; Yan Dong; Wang Jiaping; Li Yingchun

    2010-01-01

    Objective: To discuss the application of MR angiography (MRA) in deciding the puncture points of transjugular intrahepatic portosystemic shunt (TIPS). Methods: Preoperative MRA was performed in 59 patients with portal hypertension (study group) in order to search for the causes of portal hypertension, to observe the patterns and route of the hepatic and portal veins and to measure the vascular diameter at the scheduled puncture site. MRA was also performed in 50 healthy subjects, which was served as the control group. The results were compared between two groups. Results: The diseases in the study group included simple cirrhosis (n=49), cirrhosis accompanied with hepatocellular carcinoma (n=4), pure portal vein thrombosis (n=3), splenic vein stenosis (n=1) and Budd-Chiari syndrome (n=2). In study group the type I, II and III of the hepatic vein classification were seen in 14, 39 and 12 cases respectively,while in control group in 12, 34 and 14 cases respectively. In study group, the right, middle and left hepatic vein which had the diameter larger enough for puncturing existed in 52, 40 and 28 cases respectively, while in control group in 46, 34 and 23 cases respectively. The safe point for puncture via the right and the left branch of the portal vein was located beyond the distance of (16.2 ± 3.1) mm and (14.2 ± 3.8) mm respectively. Conclusion: MRA is a valuable non-invasive examination, which is of great value in determining the causes of portal hypertension and in planning the puncturing sites before performing TIPS. (authors)

  19. MRI and MR angiography of vertebral artery dissection

    International Nuclear Information System (INIS)

    Mascalchi, M.; Bianchi, M.C.; Mangiafico, S.; Ferrito, G.; Puglioli, M.; Marin, E.; Mugnai, S.; Canapicchi, R.; Quilici, N.; Inzitari, D.

    1997-01-01

    A review of 4,500 angiograms yielded 11 patients with dissection of the vertebral arteries who had MRI and (in 4 patients) MR angiography (MRA) in the acute phase of stroke. One patient with incidental discovery at arteriography of asymptomatic vertebral artery dissection and two patients with acute strokes with MRI and MRA findings consistent with vertebral artery dissection were included. Dissection occurred after neck trauma or chiropractic manipulation in 4 patients and was spontaneous in 10. Dissection involved the extracranial vertebral artery in 9 patients, the extra-intracranial junction in 1, and the intracranial artery in 4. MRI demonstrated infarcts in the brain stem, cerebellum, thalamus or temporo-occipital regions in 7 patients with extra- or extra-intracranial dissections and a solitary lateral medullary infarct in 4 patients (3 with intracranial and 1 with extra-intracranial dissection). In 2 patients no brain abnormality related to vertebral artery dissection was found and in one MRI did not show subarachnoid haemorrhage revealed by CT. Intramural dissecting haematoma appeared as crescentic or rounded high signal on T1-weighted images in 10 patients examined 3-20 days after the onset of symptoms. The abnormal vessel stood out in the low signal cerebrospinal fluid in intracranial dissections, whereas it was more difficult to detect in extracranial dissections because of the intermediate-to-high signal of the normal perivascular structures and slow flow proximal and distal to the dissection. In two patients examined within 36 h of the onset, mural thickening was of intermediate signal intensity on T1-weighted images and high signal on spin-density and T2-weighted images. MRA showed abrupt stenosis in 2 patients and disappearance of flow signal at and distal to the dissection in 5. Follow-up arteriography, MRI or MRA showed findings consistent with occlusion of the dissected vessel in 6 of 8 patients. (orig.). With 7 figs., 3 tabs

  20. MR angiography in diagnosing and following up the treatment result: arteria lusoria

    International Nuclear Information System (INIS)

    Vogl, T.J.; Juergens, M.; Harms, J.; Pegios, W.; Zimmermann, A.; Hetzer, R.; Felix, R.

    1994-01-01

    Diagnostic and therapeutic procedures are presented in a 29-year-old female patient who suffered from severe dysphagia and rapid loss in weight. In the conventional X-ray examination and barium swallow an aberrant right subclavian artery was suspected. MR imaging (MRI) and MR angiography (MRA) were done to plan the surgical correction. Post-operative MRA documented exactly the complex topography after surgical correction and the flow pattern in the implanted Gore-Tex stretch graft prosthesis. Non-invasive MR angiography renders possible the concrete planning of complex corrections of thoracic vessels replacing invasive catheter angiography. (orig.) [de

  1. 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

  2. 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.

  3. Comparison between fast contrast-enhanced MR angiography and DSA in diagnosing spinal cord vascular malformations

    International Nuclear Information System (INIS)

    Wang Wu; Li Minghua; Fang Chun; Wang Jue; Xiao Yunfeng

    2007-01-01

    Objective: To evaluate the diagnostic and clinical value of fast contrast-enhanced MR angiography (CE-MRA) with elliptic centric phase-encoding in spinal cord vascular malformations. Methods Fast three-dimensional contrast-enhanced MR angiography with elliptic centric phase-encoding and superconducting 1.5T system was applied prospectively in twenty-five consecutive patients with clinically suspected of spinal cord vascular malformations. All cases were performed with selective spinal digital subtraction angiography, including 18 cases treated by surgery and 2 of them with embolization before surgery, MR angiography follow up were undertaken in ten patients after surgery. Comparing fast contrast-enhanced MR angiography with DSA in diagnosing spinal cord vascular malformations included the origin of feeding artery, the feeding artery, the fistula or the nidus, the draining vein, and the vessel image quality based on the gold standard of selective spinal digital subtraction angiography. Results: Surgically proven diseases included spinal arteriovenous malformations(3 cases), spinal cord perimedullary arteriovenous fistulas (5 cases), spinal dural arteriovenous fistulas (8 cases), paravertebral arteriovenous fistulas (1 case), and spontaneous spinal epidural hematomas (2 eases). Comparing with DSA, the accuracy of MR angiography in diagnosing spinal cord vascular malformations; and detecting the origin of the feeding artery, the feeding artery, the shunt or the nidus and the draining vein were 93.8%, 92%, 96.2%, 100% and 100%, respectively. Overall the degree vascular enhencement were judged to be similar(P>0.05), but the vessel continuity of MRA was inferior to DSA (P<0.05). However, 9 cases of MRA showed no abnormal vascular malformation coinciding with those of surgery. Posttreatment MR angiography did not depict any abnormal vessels again. Conclusions: Fast three-dimensional contrast-enhanced MR angiography with elliptic centric phase-encoding may provide

  4. 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

  5. MR angiography in the diagnosis of tumors in the head and neck

    International Nuclear Information System (INIS)

    Vogl, T.J.; Balzer, J.O.; Juergens, M.; Lissner, J.; Grevers, G.

    1992-01-01

    40 normal individuals and 153 patients with lesions in the head and neck were examined by conventional imaging methods and by means of MR angiography (1.5 Tesla Magnetome). The problems to be solved concerned the ralationship between tumors and vessels and vascular anomalies and abnormalities at the skull base (56 cases), the facial skeleton (62 cases) and the neck (35 cases). Digital subtraction angiography was performed in 54 patients and the findings corelated with MR angiography. Optimal results were obtained by using a FISP 3D sequence; in this way arterial structures could be rendered reproducibly down to a diameter of 2 mm. The venous system in the head and neck was best shown by a FLASH 2D sequence. Correlation with arterial DSA showed high accuracy of MR angiography (91%) concerning displacement of vessels, the topography and the recognition of vascular occlusions. Our results indicate that MR angiography is a rapid and reliable procedure for evaluating the arterial and venous changes due to tumors in the head and neck region. (orig.) [de

  6. Software-triggered contrast-enhanced three-dimensional MR angiography of the intracranial arteries.

    Science.gov (United States)

    Isoda, H; Takehara, Y; Isogai, S; Takeda, H; Tanaka, T; Takahashi, M; Nozaki, A; Sun, Y

    2000-02-01

    We investigated the effectiveness of software-triggered contrast-enhanced three-dimensional (3D) MR angiography in evaluating intracranial arteries. We studied 38 patients with suspected brain lesions. Imaging was performed using a 1.5-T superconducting MR system with a commercially available head coil. To monitor signal intensity changes we used software to place a tracker volume at the basilar artery or the internal carotid artery. A 20-ml bolus of gadodiamide hydrate was administered through the antecubital vein at a rate of 2-4 ml/sec, followed by a saline flush. Three-dimensional MR angiography using a spoiled gradient-echo sequence with centric K-space ordering was triggered by the arrival of the contrast bolus in the tracker volume. Imaging times ranged from 12 to 20 sec. We used MR images to assess the effectiveness of contrast-enhanced 3D MR angiography in revealing intracranial arteries with minimal venous overlap. The software triggered imaging on the arrival of the contrast bolus in 81.6% of examinations. In 77.6% of examinations, the resulting MR angiograms revealed intracranial arteries with minimal venous overlap. Software-triggered contrast-enhanced 3D MR angiography with centric K-space ordering is a promising technique for viewing intracranial arteries.

  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. Evaluation of the portal venous system using MR angiography in patients with severe liver dysfunction

    International Nuclear Information System (INIS)

    Fukatsu, Hiroshi; Ando, Yoko; Yamakawa, Koji; Ishigaki, Takeo

    1994-01-01

    Fifteen patients of chronic liver dysfunction were examined with 2D TOF MR angiography to assess the portal venous system condition. All of the collateral pathways except esophageal varices were clearly demonstrated in all cases, portal vein thromboses were accurately diagnosed in two cases. Portal vein visualization index were determined as follows: good delineation of the main portal vein only; good delineation of the first tributaries of the intrahepatic portal vein; good delineation of the second or further tributaries. This index showed good correlation with the clinical stage proposed by Japan liver cancer study group. These results suggested that MR angiography has a potential for the evaluation of the portal system in patients with severe liver dysfunction. (author)

  9. Three-dimensional MR angiography of the intracranial circulation in neonates following extracorporeal membrane oxygenation

    International Nuclear Information System (INIS)

    Lewin, J.S.; Masaryk, T.J.; Wiznitzer, M.; Ross, J.S.; Modic, M.T.; Stork, E.K.; Bryan, P.J.; Butler, H.

    1988-01-01

    Extracorporeal membrane oxygenation (ECMO) is a neonatal systemic oxygenation technique that involves cannulation and subsequent ligation of the right internal jugular vein and common carotid artery. The purpose of this study was to implement a comprehensive neurovascular evaluation in these patients by means of a new three-dimensional MR angiography technique that used reduced echo time and voxel size, gradient refocusing, and time-of-flight effects to maximize vascular contrast. A standard T2-weighted multiecho MR imaging study was also performed. The patient population consisted of 12 infants who had undergone ECMO. Vascular examinations of diagnostic quality were performed in 80% of patients. The findings indicate that MR angiography is a reliable method for evaluation of the intracranial circulation in patients following ECMO therapy

  10. 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

  11. Anomalous vessel in the middle ear: the role of CT and MR angiography

    International Nuclear Information System (INIS)

    Caldas, J.G.M.P.; Iffenecker, C.; Lasjaunias, P.; Doyon, D.; Attal, P.

    1998-01-01

    An 8-year-old child was examined because of conductive hearing loss with a retrotympanic mass on otoscopy. CT and MR angiography showed a large inferior tympanic artery traversing the hypotympanum and joining a thin, irregular internal carotid artery with a normal middle meningeal artery. These investigations, coupled with knowledge of the embryological development allowed a diagnosis of a complex vascular anomaly in the middle ear and avoided potential surgical complications. (orig.)

  12. 3D-shaded surface rendering of gadolinium-enhanced MR angiography in congenital heart disease

    International Nuclear Information System (INIS)

    Okuda, S.; Kikinis, R.; Dumanli, H.; Geva, T.; Powell, A.J.; Chung, T.

    2000-01-01

    Background. Gadolinium-enhanced three-dimensional (3D) MR angiography is a useful imaging technique for patients with congenital heart disease. Objective. This study sought to determine the added value of creating 3D shaded surface displays compared to standard maximal intensity projection (MIP) and multiplanar reformatting (MPR) techniques when analyzing 3D MR angiography data. Materials and methods. Seventeen patients (range, 3 months to 51 years old) with a variety of congenital cardiovascular defects underwent gadolinium-enhanced 3D MR angiography of the thorax. Color-coded 3D shaded surface models were rendered from the image data using manual segmentation and computer-based algorithms. Models could be rotated, translocated, or zoomed interactively by the viewer. Information available from the 3D models was compared to analysis based on viewing standard MIP/MPR displays. Results. Median postprocessing time for the 3D models was 6 h (range, 3-25 h) compared to approximately 20 min for MIP/MPR viewing. No additional diagnostic information was gained from 3D model analysis. All major findings with MIP/MPR postprocessing were also apparent on the 3D models. Qualitatively, the 3D models were more easily interpreted and enabled adjacent vessels to be distinguished more readily. Conclusion. Routine use of 3D shaded surface reconstructions for visualization of contrast enhanced MR angiography in congenital heart disease cannot be recommended. 3D surface rendering may be more useful for presenting complex anatomy to an audience unfamiliar with congenital heart disease and as an educational tool. (orig.)

  13. Carotid Artery Stenosis: Comparison of 3D Time-of-Flight MR Angiography and Contrast-Enhanced MR Angiography at 3T

    Directory of Open Access Journals (Sweden)

    Ivan Platzek

    2014-01-01

    Full Text Available Purpose. The aim of this study was to assess the correlation of 3D time-of-flight MR angiography (TOF MRA and contrast-enhanced MR angiography (CEMRA for carotid artery stenosis evaluation at 3T. Material and Methods. Twenty-three patients (5 f, 18 m; mean age 61 y, age range 45–78 y with internal carotid artery stenosis detected with ultrasonography were examined on a 3.0T MR system. The MR examination included both 3D TOF MRA and CEMRA of the carotid arteries. MR images were evaluated independently by two board-certified radiologists. Stenosis evaluation was based on a five-point scale. Stenosis grades determined by TOF and CEMRA were compared using Spearman’s rank correlation coefficient and the Wilcoxon test. Cohen’s Kappa was used to evaluate interrater reliability. Results. CEMRA detected stenosis in 24 (52% of 46 carotids evaluated, while TOF detected stenosis in 27 (59% of 46 carotids. TOF MRA yielded significantly higher results for stenosis grade in comparison to CEMRA (P=0.014. Interrater agreement was very good for both TOF MRA (κ=0.93 and CEMRA (κ=0.93. Conclusion. At 3T, 3D TOF MRA should not be used as replacement for contrast-enhanced MRA of the carotid arteries, as it results in significantly higher stenosis grades.

  14. Inflammatory aortic arch syndrome: contrast-enhanced, three-dimensional MR - angiography in stenotic lesions

    International Nuclear Information System (INIS)

    Both, M.; Mueller-Huelsbeck, S.; Biederer, J.; Heller, M.; Reuter, M.

    2004-01-01

    Purpose: To determine the value of contrast-enhanced, three-dimensional MR angiography for the evaluation of stenotic and occlusive vascular lesions in inflammatory aortic arch syndrome. Materials and Methods: 14 patients with inflammatory aortic arch syndrome (giant cell arteritis: n = 8, Takayasu arteritis: n = 4, ankylosing spondylitis: n = 1 sarcoidosis: n = 1) underwent MR angiography of the aortic arch and the supra-aortic vessels (n = 15,2 patients were examined twice) and of the abdominal aorta (n = 2). MRA was performed using a 3D-FLASH sequence (TR/TE 4.6/1.8 ms, flip angle 30 ) on a 1.5T system. MRA imaging was compared with the findings of DSA, which served as gold standard. Results: In a total of 467 examined vascular territories, DSA revealed 50 stenoses and 35 occlusions. All lesions were detected by MRA. In 23 segments, the degree of stenosis was overestimated by MRA. Sensitivity and specificity of MRA were 100% and 94,3%, positive and negative predictive values were 73.6 and 100%, and the accuracy was 95,1%. Conclusions: Despite a tendency to overestimate stenoses, contrast-enhanced three-dimensional MR angiography is a valid, non-invasive technique in the assessment of inflammatory aortic arch syndrome. (orig.) [de

  15. Three-dimensional black blood MR angiography of the liver during breath holding. A comparison with two-dimensional time-of-flight MR angiography

    International Nuclear Information System (INIS)

    Suto, Y.; Ohuchi, Y.; Kimura, T.; Shirakawa, T.; Mizuuchi, N.; Takizawa, O.; Yamane, T.; Kamba, M.; Moriyama, S.; Ohta, Y.

    1994-01-01

    In 2-D time-of-flight MR angiography (2-D TOF MRA) of the liver, artifacts caused by respiratory motion are unavoidable. Therefore, a 3-D black blood MRA of the liver was attempted in 7 healthy volunteers, using a 3-D gradient echo sequence which allows imaging during breath holding. 2-D TOF MRA was performed as well. In all subjects, 3-D MRA allowed visualization of the trunk, 1st-, and 2nd-order branches of the portal vein without interruption. Right 3rd-order branches were visualized without interruption in 6 of 7 subjects (85%). However, with 2-D MRA, the transverse portion of the left main portal vein could not be visualized in any subject, and the periphery of the portal vein was less clear than with 3-D MRA. (orig.)

  16. 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

  17. MR angiography of eddy-current-free MR imaging system with a 3T permanent magnet

    International Nuclear Information System (INIS)

    Nishimura, H.; Watanabe, S.; Takeuchi, H.

    1991-01-01

    This paper reports that, the authors main purpose was to evaluate two-dimensional time flight MR angiography in the visualization of vascular structure by using an eddy-current-free 0.3-T permanent magnet MR imaging system. The authors have developed multisection acquisition technique for two-dimensional time-of-flight MR angiography with the use of velocity-compensated gradient echoes. MR angiograms were obtained with a ray-tracing algorithm of the new modified maximum intensity projection at various viewing angles. These angiograms are displayed on cathode-ray tubes in a high-speed cyclic mode to depict the front-rear relation of vessels for better recognition. With an eddy-current-free permanent magnet system, two-dimensional time-of-flight angiography could clearly depict intracranial vascular structure, cervical vessels, and vessels of the extremities with thin-section (2 or 3 mm) acquisition. A high flip angle (90 degrees) with a short TR enabled better differentiation between blood flow and stationary tissues. Stenosis of the carotids could be detected in accordance with digital subtraction angiography

  18. 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.)

  19. 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)

  20. MR angiography in portal hypertension: state of the art

    International Nuclear Information System (INIS)

    Vosshenrich, R.; Fischer, U.; Grabbe, E.

    2001-01-01

    When imaging the portal vascular system colour-coded sonography and CT angiography are used as an alternative to intraarterial DSA. Today fast CE 3D- MRA is the imaging modality of choice in the diagnostic of patients with portal hypertension. It enables a clear picture of the portalvenous vascular system and portalsystemic shunts. Statements regarding velocity and direction of blood flow can be made with additional use of TOF and PC techniques. CE-3D MRA can be used preoperatively before liver transplantation or shunt surgery. In the follow-up of interventional or surgical procedures exact statements concerning haemodynamically significant pathologies e.g. vascular thromboses, stenoses and occlusions can be made. Patient consent is symplify and the numbers of complications can be reduced as well as duration of surgery minimized applying this technique (orig.) [de

  1. 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)

  2. A simulation study of enhancement duration in three-dimensional contrast-enhanced MR angiography

    International Nuclear Information System (INIS)

    Ohkubo, Masaki; Ohgoshi, Yukio; Inoue, Tomoko; Naito, Kenichi; Suzuki, Kiyotaka

    2001-01-01

    In our study on three-dimensional (3D) contrast-enhanced MR angiography we performed a computer simulation to investigate quantitative vessel visibility. In the simulation, we evaluated the relative loss of signal intensity in a vessel due to shortened duration of contrast-enhancement. The mid-point of enhancement-duration was assumed to be at the point in which the data in the center of k-space (k y axis) was acquired. Signal intensity of a vessel decreased as the enhancement-duration was shortened and the diameter of the vessel was decreased. When the duration was shortened 40%, the signal intensity of a vessel in which the diameter was more than 2 pixels was preserved by approximately 70% or more. This suggests that the vessel visibility is high. When the duration was shortened 20%, the signal intensity of a vessel in which the diameter was less than 2 pixels decreased to less than approximately 40% or less. The simulation was confirmed by using 3D MR angiography with a tube phantom filled with Gd-DTPA to simulate a vessel model. At anytime during data acquisition, we could set the phantom on the region being scanned or take it out by using the ''pause'' function of the MR scanner. This made it possible to change the enhancement-duration to match the simulation. Results of the phantom study were comparable to those of the simulation, suggesting that the simulation was valid. Our results and simple techniques for both the simulation and the phantom study using the ''pause'' function, were considered useful in the study of 3D MR angiography. (author)

  3. Hemodynamics of ovarian veins: MR angiography in women with uterine leiomyomata

    International Nuclear Information System (INIS)

    Kin, Yoko; Katsumori, Tetsuya; Kasahara, Toshiyuki; Nozaki, Taiki; Ito, Hirotoshi; Nishimura, Tsunehiko

    2007-01-01

    Purpose: The passive reflux into ovarian veins (OVs) is well known as a common finding in normal asymptomatic women. The purpose of this study was to investigate the hemodynamics of OVs in women with myomatous uterus. Materials and methods: Thirty-two women with symptomatic uterine leiomyomata underwent time-of-flight MR (TOF-MR) angiography, including venography and arteriography, and contrast-enhanced MRI. The frequency of reflux into OVs on TOF-MR angiography was retrospectively assessed with uterine volume, and compared to that of normal women in previous publication. The statistical evaluation was performed using Fisher's exact test. Results: The mean uterine volume was 932 ± 612 ml (range, 301-2627 ml). The reflux into left OVs was observed in 4 of 32 women (13%) and that into right OVs was noted in 0 of 32 women (0%). These rates were significantly lower than those of normal asyptomatic women in the previous publication (p < 0.05). The reflux into OVs was observed in 0 of 19 women (0%) with 600 ml or larger myomatous uterus, whereas it was noted in 4 of the remaining 13 women (31%) with less than 600 ml myomatous uterus, with significant difference between the two groups (p = 0.02). Conclusions: We found that reflux into OVs was infrequent in the vast majority of women with myomatous uterus, especially those with larger uterus due to leiomyomata on the basis of TOF-MR angiography. These findings suggested myomatous uterus could affect the flow direction of OVs, and passive reflux into OVs might be prevented due to the influence of antegrade flow of OVs

  4. Non-contrast MR angiography for diagnosis of congenital heart disease

    International Nuclear Information System (INIS)

    Matsuo, Mikaru; Yoshioka, Kunihiro; Takahashi, Shin; Oyama, Kotaro

    2006-01-01

    Fast imaging employing steady state acquisition (FIESTA) has been reported to be suitable for cardiac imaging in adolescents and adults. The purpose of this study was to establish the applicability and limitation of MR Angiography using FIESTA in the diagnosis of congenital heart disease. Thirty-five patients with congenital heart disease underwent MR Angiography using FIESTA and the 3D Gd-enhanced fast spoiled gradient recalled acquisition in the steady state (SPGR) technique. The measurements of the vascular diameters and diagnostic quality of the two techniques were compared. Correlations between FIESTA and the 3D Gd-fast SPGR technique were excellent in vascular diameter (aAo 0.90, arch 0.78, dAo 0.92, SCA 0.70, RPA 0.90, LPA 0.95). The agreement of the vascular diameters in the Bland-Altman method was good (aAo 0.22 mm, arch 0.07 mm, dAo 0.14 mm, SCA 0.31 mm, RPA 0.45 mm, LPA 0.12 mm). However, MR angiography (MRA) by 3D Gd-enhanced SPGR had a higher resolution than that by FIESTA. Due to signal loss caused at the regions of vascular stenosis or Blalock-Taussig shunt on FIESTA, we could not evaluate the vascular diameter or patency at those lesions. FIESTA is a useful technique of non-enhanced MRA for non-invasive diagnosis of congenital heart disease. However, MRA by FIESTA was not adequate for multiplanar reconstruction. (author)

  5. MR Angiography for the Evaluation of Non-Systemic Vasculitic Neuropathy

    International Nuclear Information System (INIS)

    Sanada, M.; Terada, M.; Yasuda, H.; Suzuki, E.; Kashiwagi, A.

    2003-01-01

    Peripheral neuropathy due to vasculitis without any complications of vasculitis in other organs was first reported in 1987. This condition was termed non-systemic vasculitic neuropathy (NSVN). Although vasculitis is believed to develop in small arteries and arterioles in this disease, the level of vascular involvement has not been fully established. We present a case of NSVN followed up by MR angiography, which was thought to be useful to assess the level as well as the state of vascular lesions in this condition

  6. MR Angiography for the Evaluation of Non-Systemic Vasculitic Neuropathy

    Energy Technology Data Exchange (ETDEWEB)

    Sanada, M.; Terada, M.; Yasuda, H. [Shiga Univ. of Medical Science (Japan). Div. of Neurology; Suzuki, E.; Kashiwagi, A. [Shiga Univ. of Medical Science (Japan). Div. of Endocrinology and Metabolism

    2003-05-01

    Peripheral neuropathy due to vasculitis without any complications of vasculitis in other organs was first reported in 1987. This condition was termed non-systemic vasculitic neuropathy (NSVN). Although vasculitis is believed to develop in small arteries and arterioles in this disease, the level of vascular involvement has not been fully established. We present a case of NSVN followed up by MR angiography, which was thought to be useful to assess the level as well as the state of vascular lesions in this condition.

  7. Prognostic significance of MR angiography in patients with cerebral infarction

    International Nuclear Information System (INIS)

    Moon, Woong Jae; Kim, Jun Ho; Seo, Jeong Jin; Cho, Ki Hyun; Kim, Yun Hyeon; Kim, Jae Kyu; Kang, Heoung Keun

    1994-01-01

    This study was designed to evaluate the prognostic significance of Magnetic resonance angiography(MRA) in patients with cerebral infarction. Magnetic Resonance Imaging(MRI) and 2 dimensional or 3 dimensional Time-of-Flight MRA were performed subsequently in 83 patients with cerebral infarction proven by brain CT and clinical manifestations, using GE Signa Advantage 1.5 T. We classified the size of infarction on MRI as Extent I( 6 cm) and classified the intracranial vascular occlusion according to visualizations of intracranial vascular branches on MRA as Grade 0, Grade I, Grade II, Grade III. And we evaluated clinical outcomes of these patients according to Rankin's disability scale, compared with MRI and MRA. In 72 cases(86.8%), the larger the size of infarction on MRI, the more severe vascular occlusion on MRA, the worse the clinical outcomes were noted(p < 0.01). However, in 7 cases(8.4%) who showed huge cerebral infarction on MRI with low grade intracranial vascular occlusion on MRA, the clinical outcomes were improved. In 4 cases(4.8%) who noted small sized cerebral infarction on MRI with high grade vascular occlusion on MRA, the clinical outcomes were worsened. MRA provides additional useful information to that provided by MRI in predicting the prognosis of patients with cerebral infarction

  8. High-resolution coronary MR angiography for evaluation of patients with anomalous coronary arteries: visualization of the intramural segment

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    Biko, David M. [UCSF Benioff Children' s Hospital Oakland, Department of Diagnostic Imaging, Oakland, CA (United States); The Children' s Hospital of Philadelphia, Department of Radiology, Philadelphia, PA (United States); Chung, Claudia; Chung, Taylor [UCSF Benioff Children' s Hospital Oakland, Department of Diagnostic Imaging, Oakland, CA (United States); Hitt, David M. [Philips Healthcare, Cleveland, OH (United States); Kurio, Gregory [UCSF Benioff Children' s Hospital Oakland, Department of Cardiology, Oakland, CA (United States); Reinhartz, Olaf [UCSF Benioff Children' s Hospital Oakland, Department of Cardiac Surgery, Oakland, CA (United States)

    2015-08-15

    Anomalous origin of the coronary artery from the contralateral coronary sinus is a rare coronary anomaly associated with sudden death. The inter-arterial course is most closely associated with sudden death, but it has been suggested that the presence of an intramural segment of a right anomalous coronary is associated with more symptoms and therefore may be an important criterion for intervention in these patients. To demonstrate that MR angiography can accurately determine the presence or absence of an intramural segment in an anomalous coronary artery. All studies of children who underwent MR angiography for the evaluation of an anomalous coronary artery were retrospectively reviewed by two pediatric radiologists in consensus. Criteria for an intramural anomalous coronary artery were the presence of a small or slit-like ostium and the relative smaller size of the proximal intramural portion of the coronary artery in relation to the more distal epicardial coronary artery. The anomalous coronary artery was classified as not intramural if these two findings were absent. These findings were correlated with operative reports confirming the presence or absence of an intramural segment. Twelve patients (86%) met MR angiography criteria for the presence of an intramural course. Only 2 patients (14%) met MR angiography criteria for a non-intramural course. When correlating with intraoperative findings, MR angiography was successful in distinguishing between intramural and non-intramural anomalous coronary arteries in all cases (P = 0.01). MR angiography may be able to reliably identify the intramural segment of an anomalous coronary artery in older children using the imaging criteria of a small or slit-like ostium and relative decrease in size of the proximal portion of the anomalous coronary artery compared to the distal portion of the anomalous coronary artery. Determining the presence of the intramural segment may help with surgical planning and may be an important

  9. Dynamic contrast-enhanced subtraction MR angiography in intracranial vascular abnormalities

    International Nuclear Information System (INIS)

    Takano, K.; Ono, H.; Utsunomiya, H.; Okazaki, M.; Tanaka, A.

    1999-01-01

    We present our clinical experience with dynamic contrast-enhanced MR angiography (MRA) with subtraction for assessing intracranial vascular abnormalities. Ten patients with various cerebrovascular disorders underwent dynamic contrast-enhanced MRA on a 1.0-T system. Thirty sections (2 mm) were acquired in 29-30 s. Maximum intensity projection images and subtracted source images were compared with those obtained by conventional angiography. In all cases, the presence or absence of abnormalities in the targeted vessels, as well as the morphology of the sagittal sinuses, was clearly visualized as in conventional angiography, without any obstructions such as hyperintense hematomas or thrombi, or intraluminal turbulence. Although the temporal and spatial resolutions with current hardware are insufficient, these preliminary results suggest that dynamic contrast-enhanced MRA with subtraction may be useful for assessing vascular lesions with hemorrhage or thrombus, and the dural sinuses. (orig.)

  10. Time-resolved MR angiography of the renal artery: morphology and perfusion

    International Nuclear Information System (INIS)

    Krause, U.J.; Pabst, T.; Koestler, H.; Helbig, C.; Kenn, W.; Hahn, D.

    2002-01-01

    Purpose: To prove the hypothesis that renal artery stenosis and changes in renal perfusion can be detected with contrast-enhanced time-resolved MR angiography in a single examination. Material and Methods: In 71 patients, 137 renal arteries and 14 accessory renal arteries were studied. The examinations were performed on a 1.5 T system. A T 1 -weighted gradient echo sequence with a temporal resolution of 7 s was used. Single dose of contrast material (0.1 mmol/kg Gd-DTPA) was injected with a power injector with a flow rate of 2 ml/s. Criterion for the assessment of renal perfusion was the slope ratio of the signal intensity time curve in both kidneys. Results: Forty renal artery stenoses and one occlusion of a renal artery were detected. In 48 kidneys (35%) segmental arteries were evaluated. The accuracy of the slope ratio (limit value 0.75) concerning the detection of unilateral renal artery stenosis was 92.6% (sensitivity 75%, specificity 95.7%). Conclusion: Time-resolved MR angiography can detect changes in renal perfusion in patients with unilateral renal artery stenosis. (orig.) [de

  11. Carotid-anterior cerebral artery anastomosis on MR angiography: a university hospital-based study

    Energy Technology Data Exchange (ETDEWEB)

    Uchino, Akira; Saito, Naoko; Okada, Yoshitaka; Inoue, Kaiji [Saitama Medical University International Medical Center, Department of Diagnostic Radiology, Hidaka, Saitama (Japan)

    2012-01-15

    Rarely in the anterior circulation, an anastomosis of the carotid and anterior cerebral arteries occurs when an anomalous branch arises from the ophthalmic segment of the internal carotid artery and anastomoses with the A1-A2 junction of the anterior communicating artery. Right-side predominance is known. To our knowledge, the incidence of carotid-anterior cerebral artery anastomosis has not been reported, so we researched cases in our institution records to determine incidence and investigated characteristic features of the condition on magnetic resonance (MR) angiography. To isolate such cases, we retrospectively reviewed cranial MR angiographic images of 3,491 consecutive patients in our institution. We found three cases with carotid-anterior cerebral artery anastomosis (two men, one woman), representing an incidence of 0.086%. The anastomosis was on the right in all three cases. A normal A1 segment of the anterior cerebral artery (ACA) was present in two cases but could not be identified in the remaining case on MR angiographic images that included source images. Two of the three patients demonstrated associated arterial variations in their carotid systems. On MR angiography, we observed a 0.086% incidence of carotid-anterior cerebral artery anastomosis in our institution and reaffirmed the right-side predominance of this anomaly. We found a high frequency of other associated arterial variations in the carotid system. (orig.)

  12. Diagnosis of the hypothenar hammer syndrome by high-resolution contrast-enhanced MR angiography

    Energy Technology Data Exchange (ETDEWEB)

    Winterer, J.T.; Ghanem, N.; Schaefer, O.; Lehnhardt, S.; Thuerl, C.; Laubenberger, J. [Department of Diagnostic Radiology, University of Freiburg, Hugstetter Strasse 55, 79106 Freiburg (Germany); Roth, M. [Center of Geriatric Medicine and Gerontology Freiburg, University of Freiburg, Hugstetter Strasse 55, 79106 Freiburg (Germany); Horch, R.E. [Department of Plastic and Hand Surgery, University of Freiburg, Hugstetter Strasse 55, 79106 Freiburg (Germany)

    2002-10-01

    Our objective was to describe the imaging features of hypothenar hammer syndrome using minimally invasive contrast-enhanced MR angiography in comparison with oscillography study. In five patients with hypothenar hammer syndrome Gd-BOPTA-enhanced elliptically reordered 3D pulse sequence MR was compared with oscillography findings and clinical symptoms focusing on angiographic appearance of vessel injury, distribution pattern of hand vasculature and joining branches between the radial and ulnar artery supply. All patients showed segmental occlusion at the site of trauma impact with varying involvement of the superficial palmar arch, common volar digital arteries. Embolic disease was present in 50% of patients and could be clearly identified with MRA. Good correspondence was found between angiographic appearance including the presence of collaterals, clinical symptoms and oscillography. Bilateral comparison was helpful in distinguishing between vessel variants and pathology. Bilateral Gd-BOPTA-enhanced MR angiography is a minimally invasive method to depict clearly the localization and extent of vessel injury in hypothenar hammer syndrome providing valuable information about distribution pattern of hand vasculature and presence of collaterals; however, no flow data can be obtained. (orig.)

  13. Enhanced MR angiography of the lower extremities with synergy spine coil

    International Nuclear Information System (INIS)

    Takashima, Hiroyuki; Watanabe, Naoki

    2002-01-01

    A synergy spine coil is a phased-array coil designed for spine imaging. The coil's sensitive area is narrow in both the x-axis and y-axis directions but very wide in the z-axis direction. It is therefore suitable for using in long parts of the body, such as the spine. We used the coil for enhanced MR angiography in the lower extremities, which requires a very long field of view on the z-axis direction. Using on the NEMA (National Electrical Manufacturers Association) standard test for special-purpose coils, the sensitive volume of the synergy spine coil was first measured by using a phantom. It was found that the sensitive lengths along x-axis and y-axis were 300 mm and 120 mm, respectively, while that along z-axis could set at any length required for the examination by modifying the element number. The above area was confirmed to be sufficient for obtaining enhanced MR angiograms of the lower extremities. The results of this study showed the use of the synergy spine coil in enhanced MR angiography of the lower extremities is superior to the use of a conventional whole body coil for obtaining good MR angiograms with a good single-to-noise ratio (SNR). (author)

  14. Diagnosis of the hypothenar hammer syndrome by high-resolution contrast-enhanced MR angiography

    International Nuclear Information System (INIS)

    Winterer, J.T.; Ghanem, N.; Schaefer, O.; Lehnhardt, S.; Thuerl, C.; Laubenberger, J.; Roth, M.; Horch, R.E.

    2002-01-01

    Our objective was to describe the imaging features of hypothenar hammer syndrome using minimally invasive contrast-enhanced MR angiography in comparison with oscillography study. In five patients with hypothenar hammer syndrome Gd-BOPTA-enhanced elliptically reordered 3D pulse sequence MR was compared with oscillography findings and clinical symptoms focusing on angiographic appearance of vessel injury, distribution pattern of hand vasculature and joining branches between the radial and ulnar artery supply. All patients showed segmental occlusion at the site of trauma impact with varying involvement of the superficial palmar arch, common volar digital arteries. Embolic disease was present in 50% of patients and could be clearly identified with MRA. Good correspondence was found between angiographic appearance including the presence of collaterals, clinical symptoms and oscillography. Bilateral comparison was helpful in distinguishing between vessel variants and pathology. Bilateral Gd-BOPTA-enhanced MR angiography is a minimally invasive method to depict clearly the localization and extent of vessel injury in hypothenar hammer syndrome providing valuable information about distribution pattern of hand vasculature and presence of collaterals; however, no flow data can be obtained. (orig.)

  15. MR imaging and MR angiography in preoperative evaluation of intracranial meningiomas

    International Nuclear Information System (INIS)

    Goldmann, A.; Kunz, U.; Bader, C.; Leibing, U.; Friedrich, J.M.; Oldenkott, P.

    1994-01-01

    A group of 41 patients with intracranial meningiomas were examined by MR imaging (MRI) and MR angiography (MRA) to assess the clinical value of MRA in the preoperative evaluation of these patients. The results of MRA were compared with the results of intraarterial cerebral catheter X-ray angiography (XRA; n 19) and with the operative findings (n = 41). Our results showed a good correlation between MRA and XRA/surgery in demonstrating the relationship between the tumor and adjacent venous and arterial structures. Use of MRA was also helpful in demonstrating the degree of intrinsic tumor vascularity. It also supplied important information for operative planning. Adjunct XRA was mandatory if detailed information about tumor-feeding vessels was requested by the neurosurgeon, especially in highly vascularized angiomatous meningiomas and in meningiomas suspected of tumor feeding by vessels of the internal carotid artery. (orig.)

  16. MR imaging and MR angiography in preoperative evaluation of intracranial meningiomas

    Energy Technology Data Exchange (ETDEWEB)

    Goldmann, A. [Dept. of Diagnostic Radiology, Univ. of Ulm (Germany); Kunz, U. [Dept. of Neurosurgery, Military Hospital, Academic Hospital of the University, Ulm (Germany); Bader, C. [Dept. of Diagnostic Radiology, Univ. of Ulm (Germany); Leibing, U. [Dept. of Diagnostic Radiology, Univ. of Ulm (Germany); Friedrich, J.M. [Dept. of Diagnostic Radiology, Univ. of Ulm (Germany); Oldenkott, P. [Dept. of Neurosurgery, Military Hospital, Academic Hospital of the University, Ulm (Germany)

    1994-12-01

    A group of 41 patients with intracranial meningiomas were examined by MR imaging (MRI) and MR angiography (MRA) to assess the clinical value of MRA in the preoperative evaluation of these patients. The results of MRA were compared with the results of intraarterial cerebral catheter X-ray angiography (XRA; n = 19) and with the operative findings (n = 41). Our results showed a good correlation between MRA and XRA/surgery in demonstrating the relationship between the tumor and adjacent venous and arterial structures. Use of MRA was also helpful in demonstrating the degree of intrinsic tumor vascularity. It also supplied important information for operative planning. Adjunct XRA was mandatory if detailed information about tumor-feeding vessels was requested by the neurosurgeon, especially in highly vascularized angiomatous meningiomas and in meningiomas suspected of tumor feeding by vessels of the internal carotid artery. (orig.)

  17. MR angiography in the evaluation of a renovascular cause of neonatal hypertension

    International Nuclear Information System (INIS)

    Mustafa, Amira E.; Valentini, Rudolph P.; Mattoo, Tej K.; Bloom, David A.; Imam, Abubakr A.

    2006-01-01

    Neonatal hypertension occurs in 2% of all infants and it is caused by renovascular abnormalities in 70% of these infants. The gold standard for diagnosing renovascular disease is conventional renal angiography. However, in neonates the procedure is not commonly used because of its invasive and technically challenging nature. MRI and MR angiography (MRA) are less invasive yet reliable means of detecting renovascular disease in adults. There is minimal literature on the use of MRI/MRA in neonatal hypertension. We report a neonate with hypertension secondary to a renovascular abnormality in which MRI/MRA was helpful in uncovering segmental renal artery stenosis. The infant underwent partial nephrectomy with subsequent resolution of his hypertension. Further studies are needed to validate the use of MRI/MRA in the evaluation of neonatal hypertension. (orig.)

  18. Clinical application of gadolinium-enhanced three-dimensional pulmonary MR angiography

    International Nuclear Information System (INIS)

    Takano, Katsuyuki

    1999-01-01

    Twenty-nine patients with suspected pulmonary lesions, and three normal volunteers, underwent gadolinium-enhanced three-dimensional (3D) pulmonary MR angiography (MRA). The MRA were obtained during intravenous administration of gadolinium-based contrast material, in a single breath-hold. Conspicuity of the normal pulmonary segmental arteries was estimated on the MRA. Abnormal findings such as ''vascular involvement'', ''abnormal connection'', stenosis'', or ''dilatation'' on the MRA were compared with those on conventional angiography or CT. Normal pulmonary segmental arteries, except for A 4,5,6,8and9 of the left pulmonary artery, could be clearly visualized. Blind reading of four different findings lead to characteristic findings for each pulmonary disease that can be aid in their differential diagnoses. This technique shows promise as a noninvasive diagnosis of lung diseases. (author)

  19. TOF MR angiography of cerebral arteriovenous malformations before and after radiotherapy

    International Nuclear Information System (INIS)

    Schlemmer, H.P.; Hess, T.; Debus, J.; Knopp, M.V.; Schad, L.R.; Engenhart, R.

    1994-01-01

    We studied whether 3D time-of-flight (TOF) MR angiography can be used for therapy planning and monitoring. MRI and TOF-MRA studies of 28 patients undergoing radiotherapy were evaluated. They were compared to conventional angiography to assess the MRA study. A correct identification of the arterial feeder and the nidus was possible in about 75% of the patients. In combination with the MRI study, an important 3D dataset for treatment planning could be obtained that includes therapeutically relevant information on the localization and spatial structure of the AVM as well as the adjacent brain tissue. As a noninvasive technique, close-meshed follow-up studies could be performed with MRA. (orig./MG) [de

  20. 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)

  1. Analysis of flow dynamics of main pulmonary artery by cine phase contrast MR angiography

    International Nuclear Information System (INIS)

    Honda, Norinari; Machida, Kikuo; Mamiya, Toshio

    1996-01-01

    Nineteen studies of cine phase contrast MR angiography (PCMRA) of main pulmonary artery (MPA) entered the study. Cine PCMRA was obtained by a 1.5T MR imager with a gradient echo sequence coupled with velocity encoding bipolar pulses. Retrospective EKG gating was used. Mean velocity, maximum velocity, and maximum flow rate of MPA were 6.2 to 28 cm/s (mean/SD 13/5.1, n=18), 61 to 148 cm/s (mean/SD 102/30, n=13), and 12,561 to 30,113 ml/min (mean/SD 18,730/5,464, n=18), respectively. Retrograde flow in the MPA was noted to begin at late-to mid-systole. Retrograde flow occurred first in the posterior part (15/19) or occurred from periphery (4/19). Thus hemodynamic parameters and velocity maps of MPA can be obtained by cine PCMRA. (author)

  2. Dynamic coronary MR angiography in a pig model with hyperpolarized water

    DEFF Research Database (Denmark)

    Lipsø, Hans Kasper Wigh; Hansen, Esben Søvsø Szocska; Tougaard, Rasmus Stilling

    2018-01-01

    To investigate dynamic coronary MR angiography using hyperpolarized water as a positive contrast agent. Hyperpolarization can increase the signal by several orders of magnitude, and has recently been translated to human cardiac application. The aim was to achieve large 1 H signal enhancement...... to allow high-resolution imaging of the coronary arteries. Protons in D2 O were hyperpolarized by dissolution dynamic nuclear polarization. A total of 18 mL of hyperpolarized water was injected into the coronary arteries of healthy pigs (N = 9; 3 injections in 3 animals). The MRI images were acquired...... with a gradient-echo sequence in an oblique slab covering the main left coronary arteries with 0.55 mm in-plane resolution. The acquisition time was 870 ms per frame. A more than 200-fold signal enhancement compared with thermally polarized water at 3 T was obtained. Coronary angiographic images with a signal...

  3. MR angiography of the carotid arteries and intracranial circulation: advantage of a high relaxivity contrast agent

    International Nuclear Information System (INIS)

    Anzalone, N.; Scotti, R.; Iadanza, A.

    2006-01-01

    Several studies have shown the usefulness of contrast-enhanced MR angiography (CE-MRA) for imaging the supraortic vessels, and, as a consequence, it has rapidly become a routine imaging modality. The main advantage over unenhanced techniques is the possibility to acquire larger volumes, allowing demonstration of the carotid artery from its origin to the intracranial portion. Most published studies on CE-MRA of the carotid arteries have been performed with standard Gd-based chelates whose T1 relaxivity values are similar. Recently new gadolinium chelates such as gadobenate dimeglumine (Gd-BOP-TA, MultiHance; Bracco Imaging, Milan, Italy) have been developed which have markedly higher intravascular T1 relaxivity values. When administered at an equivalent dose to that of a standard agent, these newer contrast agents produce significantly greater intravascular signal enhancement. The availability of an appropriate high-relaxivity contrast agent might also help to overcome some of the intrinsic technical problems (e. g. those related to flow) that affect time-of-flight (TOF) and phase contrast (PC) MR angiography of the intracranial vasculature. To avoid the problem of superimposition of veins, ultrafast gradient echo MRA techniques with very short TR and TE have been developed. Although the precise sequence parameters vary between manufacturers, they are basically similar. The choice between performing a time-resolved or high spatial resolution CE-MRA examination depends upon the precise clinical application. The most common applications include the study of cerebral aneurysms, arteriovenous malformations, dural arteriovenous fistulas and dural venous diseases

  4. Renal contrast-enhanced MR angiography: timing errors and accurate depiction of renal artery origins.

    Science.gov (United States)

    Schmidt, Maria A; Morgan, Robert

    2008-10-01

    To investigate bolus timing artifacts that impair depiction of renal arteries at contrast material-enhanced magnetic resonance (MR) angiography and to determine the effect of contrast agent infusion rates on artifact generation. Renal contrast-enhanced MR angiography was simulated for a variety of infusion schemes, assuming both correct and incorrect timing between data acquisition and contrast agent injection. In addition, the ethics committee approved the retrospective evaluation of clinical breath-hold renal contrast-enhanced MR angiographic studies obtained with automated detection of contrast agent arrival. Twenty-two studies were evaluated for their ability to depict the origin of renal arteries in patent vessels and for any signs of timing errors. Simulations showed that a completely artifactual stenosis or an artifactual overestimation of an existing stenosis at the renal artery origin can be caused by timing errors of the order of 5 seconds in examinations performed with contrast agent infusion rates compatible with or higher than those of hand injections. Lower infusion rates make the studies more likely to accurately depict the origin of the renal arteries. In approximately one-third of all clinical examinations, different contrast agent uptake rates were detected on the left and right sides of the body, and thus allowed us to confirm that it is often impossible to optimize depiction of both renal arteries. In three renal arteries, a signal void was found at the origin in a patent vessel, and delayed contrast agent arrival was confirmed. Computer simulations and clinical examinations showed that timing errors impair the accurate depiction of renal artery origins. (c) RSNA, 2008.

  5. Acute chest pain: The role of MR imaging and MR angiography

    Energy Technology Data Exchange (ETDEWEB)

    Hunold, Peter, E-mail: peter.hunold@uk-sh.de [Clinic for Radiology and Nuclear Medicine, University Hospital Schleswig-Holstein, Campus Lübeck, Ratzeburger Allee 160, 23538 Lübeck (Germany); Bischoff, Peter, E-mail: peter.bischoff@uk-sh.de [Clinic for Radiology and Nuclear Medicine, University Hospital Schleswig-Holstein, Campus Lübeck, Ratzeburger Allee 160, 23538 Lübeck (Germany); Barkhausen, Jörg, E-mail: joerg.barkhausen@uk-sh.de [Clinic for Radiology and Nuclear Medicine, University Hospital Schleswig-Holstein, Campus Lübeck, Ratzeburger Allee 160, 23538 Lübeck (Germany); Vogt, Florian M., E-mail: florian.vogt@uk-sh.de [Clinic for Radiology and Nuclear Medicine, University Hospital Schleswig-Holstein, Campus Lübeck, Ratzeburger Allee 160, 23538 Lübeck (Germany)

    2012-12-15

    MR imaging (MRI) and MR angiography (MRA) have gained a high level of diagnostic accuracy in cardiovascular disease. MRI in cardiac disease has been established as the non-invasive standard of reference in many pathologies. However, in acute chest pain the situation is somewhat special since many of the patients presenting in the emergency department suffer from potentially life-threatening disease including acute coronary syndrome, pulmonary embolism, and acute aortic syndrome. Those patients need a fast and definitive evaluation under continuous monitoring of vital parameters. Due to those requirements MRI seems to be less suitable compared to X-ray coronary angiography and multislice computed tomography angiography (CTA). However, MRI allows for a comprehensive assessment of all clinically stable patients providing unique information on the cardiovascular system including ischemia, inflammation and function. Furthermore, MRI and MRA are considered the method of choice in patients with contraindications to CTA and for regular follow-up in known aortic disease. This review addresses specific features of MRI and MRA for different cardiovascular conditions presenting with acute chest pain.

  6. 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)

  7. Accuracy of 3 T MR angiography in vertebral artery stenosis and coincidence with other cerebrovascular stenoses

    International Nuclear Information System (INIS)

    Choi, Hyun Seok; Kim, Dong Ik; Kim, Dong Joon; Kim, Jinna; Kim, Eun Soo; Lee, Seung-Koo

    2010-01-01

    Ostium of vertebral artery (VA) is a common site of pseudostenosis on contrast-enhanced MR angiography (CE-MRA). The purpose of this study was to determine the diagnostic accuracy of CE-MRA at 3 T in the evaluation of ostial stenosis of VA and to find associated coincidental stenoses using logistic regression analysis. One hundred and thirty-five VA ostial regions from 72 patients who received CE-MRA of neck vessels, intracranial time of flight (TOF) MRA, and digital subtraction angiography (DSA) were retrospectively reviewed. The sensitivity and specificity of the CE-MRA in detection of ostial stenosis were calculated with reference standard of DSA. Ostial stenosis on MRA was correlated with coincidental lesions in intracranial and cervical arteries by logistic regression analysis. The sensitivity and specificity of the CE-MRA were 100% and 80.4% for detection of significant stenosis. In case of significant stenoses, CE-MRA showed a tendency of overestimation with a false-positive rate of 52.5%. Logistic regression analysis showed that the stenoses of middle cerebral artery (MCA) on TOF MRA was associated with significant stenoses of VA ostia (OR = 5.84, 95% confidence intervals 1.41-24.17). CE-MRA is sensitive in detection of VA ostial stenosis although it has high false-positive rate. True positive ostial stenosis should be considered in cases of coincidental stenoses of MCA on TOF MRA. (orig.)

  8. Evaluation of MR angiography and blood flow measurement in abdominal and peripheral arterial occlusive disease

    Energy Technology Data Exchange (ETDEWEB)

    Tabuchi, Kenji [Dokkyo Univ. School of Medicine, Mibu, Tochigi (Japan)

    2000-03-01

    To assess the characteristics of blood flow measurement with MR Angiography (MRA) to evaluate the status of vascular stenoses, two or three dimensional time-of-flight MRA and velocity-encoded cine MR were performed in the 230 segments of 35 patients, with abdominal and peripheral arterial occlusive diseases. In 11 of these 35 patients digital subtraction angiography was additionally underwent, and the stenotic findings was compared with MRA. There were 17 segments in which the velocity could not be measured, because the blood flow exceeded the upper limit of peak-encoded velocity (VENC) which was set at 120 cm/sec. Therefore, it is necessary to set the upper limit of VENC at higher than 120 cm/sec. There were 11 stenotic findings in DSA and 20 stenotic findings in MRA. Pulsatility Index (PI=(max velocity-min. velocity)/average velocity) were used for evaluating the blood flow waveform, and there were significant difference between the 11 stenotic findings of DSA and the others'. In summery, MRA was considered as useful examination to assess the degree of the vascular stenoses in abdominal and peripheral arterial occlusive disease. (author)

  9. Comparison of two-dimensional MR angiography and microsphere measurement of renal blood flow for detection of renal artery stenosis

    International Nuclear Information System (INIS)

    Powers, T.A.; Lorenz, C.H.; Shetty, A.N.; Holburn, G.E.; Price, R.R.

    1990-01-01

    This paper compares depiction of the renal arteries by MR angiography to renal blood flow as determined with microspheres in a dog model of renal artery stenosis. A left renal artery stenosis was created by placement of a silk ligature. Nb-95-labeled microspheres were injected into the left ventricle and a reference blood sample was drawn. The dog was imaged in the 1.5-T MR imager with two-dimensional MR angiography sequences. The kidneys were excised, weighted, divided into sections, and counted. Two dogs were studied to date. In dog 1, left renal blood flow (RBF) was 42 mL/min/100 g and right RBF was 337 mL/min/100 g. In dog 2 left RBF was 44 mL/min/100 g and right RBF was 608 mL/min/100 g

  10. Preoperative evaluation of neurovascular relationship by using contrast-enhanced and unenhanced 3D time-of-flight MR angiography in patients with trigeminal neuralgia

    International Nuclear Information System (INIS)

    Qin, Zhou; Zhiling, Liu; Chuanfu, Li; Qingshi Zeng; Chuncheng, Qu; Shilei, Ni

    2011-01-01

    Background Microvascular decompression is an etiological strategy for the therapy of trigeminal neuralgia (TN). Preoperative identification of neurovascular compression, therefore, could have an impact on the determination of appropriate treatment for TN. Purpose To evaluate the value of contrast-enhanced and unenhanced three-dimensional (3D) time-of-flight (TOF) MR angiography in the visualization of neurovascular relationship in patients with TN. Material and Methods Thirty-seven patients with unilateral TN underwent unenhanced and contrast-enhanced 3D TOF MR angiography with a 3.0-T MR system. Images were reviewed by a radiologist blinded to clinical details. Vascular contact with the trigeminal nerve was identified, and the nature of the involved vessels (artery or vein) was determined. All patients underwent microvascular decompression. Results In 37 patients with TN, contrast-enhanced 3D TOF MR angiography identified surgically verified neurovascular contact in 35 of 36 symptomatic nerves, and there was no false-positive. Based on surgical findings, the sensitivity of MR imaging was 97.2% and specificity 100%. The nature of the offending vessel was correctly identified in 94.4% of the patients by using the combination of contrast-enhanced and unenhanced MR angiography. Conclusion Contrast-enhanced 3D TOF MR angiography is useful in the detection of vascular contact with the trigeminal nerve in patients with TN, and this MR imaging in combination with unenhanced MR angiography could help in the identification of the nature of the responsible vessels

  11. 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.)

  12. Technique for arterial-phase contrast-enhanced three-dimensional MR angiography of the carotid and vertebral arteries.

    Science.gov (United States)

    Isoda, H; Takehara, Y; Isogai, S; Takeda, H; Kaneko, M; Nozaki, A; Sun, Y; Foo, T K

    1998-08-01

    Our goal was to evaluate whether contrast-enhanced three-dimensional MR angiography using the MR Smartprep technique would enable us to obtain arterial-phase MR angiograms of the carotid and vertebral arteries. The study included 35 patients with suspected lesions of the neck in whom the MR Smartprep technique was used for MR angiography performed with a 1.5-T superconducting system. The tracker volume was placed primarily in the middle part of the right common carotid artery. The imaging volume was placed in a coronal direction to include the carotid and vertebral arteries from the aortic arch to the skull base. A centric phase-ordering scheme was used. Imaging times were 20 to 38 seconds for 14 patients and 11 to 16 seconds for 21 patients. By using a smaller tracker volume and an imaging time of less than 16 seconds, we were able to achieve a 100% successful triggering rate and to delineate selectively arterial-phase carotid and vertebral arteries with almost no venous contamination. Contract-enhanced 3-D MR angiography with the MR Smartprep technique was useful for showing arterial-phase carotid and vertebral arteries selectively.

  13. Pulmonary MR angiography and perfusion imaging—A review of methods and applications

    Energy Technology Data Exchange (ETDEWEB)

    Johns, Christopher S.; Swift, Andrew J.; Hughes, Paul J.C. [University of Sheffield (United Kingdom); Ohno, Yoshiharu [Division of Functional and Diagnostic Imaging Research, Department of Radiology, KobeUniversity Graduate School of Medicine, Kobe, Hyogo (Japan); Schiebler, Mark [UW-Madison School of Medicine and Public Health, Madison, WI (United States); Wild, Jim M., E-mail: j.m.wild@sheffield.ac.uk [University of Sheffield (United Kingdom)

    2017-01-15

    Highlights: • This article represents an overview of the methodology and clinical applications of pulmonary MRA and perfusion imaging. • Both contrast enhanced and non-contrast enhanced metholodology for MRA and perfusion are covered. • The current clinical uses and future directions of MRA and MR perfusion are discussed. - Abstract: The pulmonary vasculature and its role in perfusion and gas exchange is an important consideration in many conditions of the lung and heart. Currently the mainstay of imaging of the vasculature and perfusion of the lungs lies with CT and nuclear medicine perfusion scans, both of which require ionizing radiation exposure. Improvements in MRI techniques have increased the use of MRI in pulmonary vascular imaging. Here we review MRI methods for imaging the pulmonary vasculature and pulmonary perfusion, both using contrast enhanced and non-contrast enhanced methodology. In many centres pulmonary MR angiography and dynamic contrast enhanced perfusion MRI are now well established in the routine workflow of patients particularly with pulmonary hypertension and thromboembolic disease. However, these imaging modalities offer exciting new directions for future research and clinical use in other respiratory diseases where consideration of pulmonary perfusion and gas exchange can provide insight in to pathophysiology.

  14. MR angiography in the diagnosis of cerebral venous angiomas: 3D TOF versus phase contrast

    International Nuclear Information System (INIS)

    Choi, Hye Young; Kim, Myung Hyen; Park, Hyung Chun; Lee, Min Hee; Kim, Yoo Kyung; Lee, Sun Wha

    1995-01-01

    To seek adequate sequence of MR angiography (MRA) on developmental venous anomaly in the brain. We collected ten cases who demonstrated developmental venous anomaly on MR image. Eight patients among them, both 3D time-of-fight (TOF) with or without Gadolinium-DTPA enhancement and phase contrast(PC) were performed: TOF without enhancement in five. TOF with enhancement in six, and PC with 10 cm/sec in five, PC with 30 cm/sec in three, and PC with 5 cm/sec velocity encoding (VNEC) in two cases. On enhanced 3D TOF, both dilated collecting veins and medullary veins were well depicted in five of six cases, however, the signal intensity of the collecting and medullary veins are less than arteries. Dilated hyperintense collecting veins were well demonstrated on 3D PC with below the 10 cm/sec VNEC in all seven cases, but the medullary veins were poorly defined. Unenhanced 3D TOF MRA could not reveal any dilated collecting and medullary veins in all five cases. Enhanced 3D TOF could demonstrate the collecting and medullary veins of developmental venous anomaly, however, 3D PC with below the 10 cm/sec VNEC could show the dilated collecting and larger draining veins. We considered that combined enhanced 3D TOF MRA and PC with VENC 10 cm/sec can substitute for conventional angiogram in the diagnosis of developmental venous anomaly

  15. Contrast-enhanced thoracic 3D-MR angiography in infants and children

    International Nuclear Information System (INIS)

    Holmqvist, C.; Larsson, E.M.; Staahlberg, F.; Laurin, S.

    2000-01-01

    To optimise breath-hold contrast-enhanced MR angiography (MRA) in infants and children with suspected congenital heart or thoracic vessel malformation. Thirty-nine children (median age 1 year) were examined, using five different ultrafast MRA sequences with a TR between 3.2 and 5.0 ms and the contrast agent meglumine gadoterate. A test injection was used to determine contrast travel time. Different parameters for contrast injection were evaluated. Signal-to-noise ratio (SNR) measurements were performed and image quality and injection timing were evaluated. MRA was successful in all patients and image quality was considered very good in 52%. Adequate SNR was achieved with no significant differences between the MR sequences. SNR decreased only 25 - 30% between subsequent scans. The mean contrast dose was 0.23 mmol/kg. The mean scan time was 12.5±3.8 s; the shorter scan times made dynamic examinations possible with high temporal resolution. Highest spatial resolution was obtained with TR 4.6/5.0 sequences. A contrast dose of 0.2 mmol/kg b.w. is recommended with an injection rate of 0.5 to 1.2 ml/s, depending on patient size and scan time. The scan delay time should equal the contrast travel time for optimal vessel enhancement. In the future, contrast-enhanced MRA may be a potential alternative to angiocardiography in infants and children

  16. Pulmonary MR angiography and perfusion imaging—A review of methods and applications

    International Nuclear Information System (INIS)

    Johns, Christopher S.; Swift, Andrew J.; Hughes, Paul J.C.; Ohno, Yoshiharu; Schiebler, Mark; Wild, Jim M.

    2017-01-01

    Highlights: • This article represents an overview of the methodology and clinical applications of pulmonary MRA and perfusion imaging. • Both contrast enhanced and non-contrast enhanced metholodology for MRA and perfusion are covered. • The current clinical uses and future directions of MRA and MR perfusion are discussed. - Abstract: The pulmonary vasculature and its role in perfusion and gas exchange is an important consideration in many conditions of the lung and heart. Currently the mainstay of imaging of the vasculature and perfusion of the lungs lies with CT and nuclear medicine perfusion scans, both of which require ionizing radiation exposure. Improvements in MRI techniques have increased the use of MRI in pulmonary vascular imaging. Here we review MRI methods for imaging the pulmonary vasculature and pulmonary perfusion, both using contrast enhanced and non-contrast enhanced methodology. In many centres pulmonary MR angiography and dynamic contrast enhanced perfusion MRI are now well established in the routine workflow of patients particularly with pulmonary hypertension and thromboembolic disease. However, these imaging modalities offer exciting new directions for future research and clinical use in other respiratory diseases where consideration of pulmonary perfusion and gas exchange can provide insight in to pathophysiology.

  17. Usefulness of MR angiography with fat- and water-suppression technique

    International Nuclear Information System (INIS)

    Ohta, Fumihito; Kagawa, Takato; Kawamitsu, Hideaki; Fukuma, Atsushi; Nagao, Seiichi; Takaya, Mikio; Kimura, Reishin; Yamasaki, Toshiki; Moritake, Kouzo

    1994-01-01

    The purpose of this study was to improve visualization of intracranial vessels by the use of time-of-flight MR angiography with the fat- and water-suppression technique (TOF-MRA-presat). Two groups of individuals were studied. They were 35 patients with ischemic cerebrovascular disorders (lacunar group) and 22 volunteers (control group). TOF-MRA-presat suppressed the signal of the background tissue, including fat and brain parenchyma. The contrast between background tissue and blood vessels was thus improved. The visibility of the ophthalmic artery, the posterior communicating artery, and the superior cerebellar artery in the control group increased noticeably in the TOF-MRA-presat images as compared with the TOF-MRA images. Similarly, the visibility of the insular segment of the middle cerebral artery, the posterior temporal artery, and the calcarine artery in the lacunar group was also better in TOF-MRA-presat images than in TOF-MRA-images. These results indicate that TOF-MRA-presat dose improve the visualization of intracranial vessels. (author)

  18. Evaluation of paraclinoid aneurysm by using contrast-enhanced MR angiography

    International Nuclear Information System (INIS)

    Tsuboi, Toshiyuki; Takahashi, Kazuya; Date, Isao; Mandai, Shinya; Kinugasa, Kazushi; Nishimoto, Akira

    2004-01-01

    Juxta-dural ring aneurysms of the internal carotid artery have different clinical courses and risks of subarachnoid hemorrhage (SAH) depending upon their positions in the intradural or extradural spaces. The goal of this study was to localize such aneurysms using contrast enhanced-MR Angiography (CE-MRA). CE-MRA studies were performed in 18 patients with juxta-dural ring aneurysms using three-dimensional time-of-flight spoiled gradient-recalled acquisition in the steady state (3D-TOF-SPGR) sequence. Imaging parameters were as follows: 33/3.4/1 (repetition time/echo time/number of excitation (TR/TE/NEX)), flip angle 25 deg, 256 x 192 matrix, 0.8-mm slice thickness, 60 sections in total (one slab), 180-mm field of view, with no magnetization transfer contrast (MTC), superior saturation (S sat) pulse, total imaging time 6 minutes 53 seconds. We evaluated both the source images of CE-MRA and multiplanar reconstruction (MPR) images. When the hyperintensity of the aneurysm was located within the hyperintensity of the contrast-enhanced cavernous sinus, we diagnosed the lesion as an intracavernous, ''extradural'' aneurysm. In addition, we compared CE-MRA with operative findings. Seven patients out of 18 were treated surgically. In all, MRI findings corresponded well with the operative findings. We believe CE-MRA and its MPR images using 3D-TOF-SPGR sequence is a useful technique to evaluate juxta-dural ring aneurysms. (author)

  19. Branching pattern of lenticulostriate arteries observed by MR angiography at 3.0 T

    International Nuclear Information System (INIS)

    Akashi, Toshiaki; Taoka, Toshiaki; Ochi, Tomoko; Miyasaka, Toshiteru; Wada, Takeshi; Sakamoto, Masahiko; Kichikawa, Kimihiko; Takewa, Megumi

    2012-01-01

    We hypothesized that the pattern of branching of the lenticulostriate arteries (LSAs) is involved in the variation of the distribution of the infarction within the LSA region. Our purpose was to evaluate the visibility of LSAs in 3D time-of-flight (TOF) MR angiography (MRA) with a 3.0 T scanner and to investigate the branching patterns of LSAs. We performed 3D TOF MRA at 3.0 T for 100 healthy subjects. We assessed the number of LSAs and the number of branches arising from each LSA by evaluating MRA source images. In 200 hemispheres, 330 LSAs were visualized (mean=1.65/hemisphere). In 3.5% of all hemispheres, no LSA was depicted; one LSA was depicted in 39%, two in 46.5%, and three in 11%. The maximum number of depicted LSA branches was five in 2% of all subjects, four in 7%, three in 26%, and two in 49% (mean=2.3/subject). A large LSA trunk with three or more branches was found in 35% of subjects. Visualization of LSAs was possible in 96.5% of subjects by use of 3.0 T MRA. LSA branching patterns were variable, and a large LSA trunk with three or more branches was common. (author)

  20. 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

  1. The diagnostic value of three-dimensional dynamic contrast-enhanced MR angiography for intracranial aneurysms

    International Nuclear Information System (INIS)

    Liu Qi; Lu Jianping; Wang Fei; Wang Li; Tian Jianming; Jin Aiguo; Zeng Hao

    2003-01-01

    Objective: To assess the clinical value of three-dimensional dynamic contrast-enhanced MR angiography (3D DCE-MRA) in the detection for intracranial aneurysm. Methods: 3D DCE-MRA was performed in 54 patients highly suspected with intracranial aneurysms. Then conventional digital subtraction angiography (DSA) and feasible endovascular treatment were performed simultaneously. A three-dimensional fast imaging with steady state precession (3D FISP) was used for 3D DCE-MRA(Gd-DTPA dose, 0.2 mmol per kilogram for body weight; acquisition time, 10 seconds). The source images were subtracted from mask images and transferred to computer workstation. All images were subsequently post-processed using three-dimensional reconstruction. 3D DCE-MRA images and DSA images were compared for demonstration of the aneurysm, its neck, and relationship with parent artery, and the usefulness for endovascular treatment was evaluated. Results: There were 39 cases with 45 intracranial aneurysms. The sensitivity, specificity, and accuracy of 3D DCE-MRA were 96%, 73% and 90%, respectively. Aneurysm and its neck depiction at 3D DCE-MRA was significantly better than that at DSA, especially for aneurysms adjacent to the cavernous sinus and near the PICA of vertebral artery. 3D DEC-MRA could guide neurosurgeons to the desired DSA projection, and helped them make plan for interventional or surgical treatment in advance. But the diagnosis should be very carefully made for small aneurysms located in the periphery and the arterial bifurcation. Conclusion: 3D DEC-MRA is a fast, noninvasive and efficient technique for diagnosing intracranial aneurysms. Its three dimensional information is helpful for DSA demonstration and treatment planning. Any uncertain diagnosis requires DSA confirmation

  2. 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.

  3. Contrast-enhanced MR angiography vs intra-arterial digital subtraction angiography for carotid imaging: activity-based cost analysis

    International Nuclear Information System (INIS)

    U-King-Im, Jean Marie; Cross, Justin J.; Higgins, Nicholas J.; Graves, Martin J.; Antoun, Nagui M.; Gillard, Jonathan H.; Hollingworth, William; Trivedi, Rikin A.; Kirkpatrick, Peter J.

    2004-01-01

    The aim of this study was to compare the costs of performing contrast-enhanced MR angiography (CE MRA) with intra-arterial digital subtraction angiography (DSA) for the evaluation of carotid atherosclerotic disease. Activity-based cost analysis was used to identify the costs of performing each procedure. The variable direct costs of performing CE MRA and DSA were determined in 20 patients by using detailed time and motion studies. All personnel directly involved in the cases were tracked to the nearest minute and all consumable items used were recorded. Moreover, procedure times were prospectively recorded for an additional 80 patients who underwent both DSA and CE MRA. The variable direct costs of bed usage in the angiography day-case unit, all direct fixed costs as well as indirect costs were assessed from hospital and departmental accounting records. Total costs for each procedure were calculated and compared using Wilcoxon signed-rank sum test. Mean aggregate costs were and euro;721 for DSA and and euro;306 for CE MRA, resulting in potential savings of and euro;415 per patient (p<0.0001). On average, a DSA procedure thus cost approximately 2.4 (95% confidence intervals: 2.2-2.6) times more than CE MRA to our medical institution. Sensitivity analyses confirmed the robustness of our conclusions across wide ranges of plausible values for various parameters. Assuming equal diagnostic performance, institutions may have substantial cost savings if CE MRA is used instead of DSA for carotid imaging. (orig.)

  4. Contrast-enhanced MR angiography vs intra-arterial digital subtraction angiography for carotid imaging: activity-based cost analysis

    Energy Technology Data Exchange (ETDEWEB)

    U-King-Im, Jean Marie; Cross, Justin J.; Higgins, Nicholas J.; Graves, Martin J.; Antoun, Nagui M.; Gillard, Jonathan H. [University Department of Radiology, Addenbrooke' s Hospital, CB2 2QQ, Cambridge (United Kingdom); Hollingworth, William [Department of Radiology, University of Washington, WA 98103, Seattle (United States); Trivedi, Rikin A. [University Department of Radiology, Addenbrooke' s Hospital, CB2 2QQ, Cambridge (United Kingdom); Academic Department of Neurosurgery, Addenbrooke' s Hospital, CB2 2QQ, Cambridge (United Kingdom); Kirkpatrick, Peter J. [Academic Department of Neurosurgery, Addenbrooke' s Hospital, CB2 2QQ, Cambridge (United Kingdom)

    2004-04-01

    The aim of this study was to compare the costs of performing contrast-enhanced MR angiography (CE MRA) with intra-arterial digital subtraction angiography (DSA) for the evaluation of carotid atherosclerotic disease. Activity-based cost analysis was used to identify the costs of performing each procedure. The variable direct costs of performing CE MRA and DSA were determined in 20 patients by using detailed time and motion studies. All personnel directly involved in the cases were tracked to the nearest minute and all consumable items used were recorded. Moreover, procedure times were prospectively recorded for an additional 80 patients who underwent both DSA and CE MRA. The variable direct costs of bed usage in the angiography day-case unit, all direct fixed costs as well as indirect costs were assessed from hospital and departmental accounting records. Total costs for each procedure were calculated and compared using Wilcoxon signed-rank sum test. Mean aggregate costs were and euro;721 for DSA and and euro;306 for CE MRA, resulting in potential savings of and euro;415 per patient (p<0.0001). On average, a DSA procedure thus cost approximately 2.4 (95% confidence intervals: 2.2-2.6) times more than CE MRA to our medical institution. Sensitivity analyses confirmed the robustness of our conclusions across wide ranges of plausible values for various parameters. Assuming equal diagnostic performance, institutions may have substantial cost savings if CE MRA is used instead of DSA for carotid imaging. (orig.)

  5. Preoperative evaluation of the artery of adamkiewicz by MR angiography and CT angiography in patients with a thoracic aortic aneurysm

    International Nuclear Information System (INIS)

    Niinuma, Hiroyuki; Ohira, Atsushi; Makita, Shinji; Moriai, Yoshiteru; Hiramori, Katsuhiko; Yoshioka, Kunihiro; Nakajima, Takayuki; Kawazoe, Kohei

    2002-01-01

    Paraplegia is known as an extremely serious and important complication of surgical repair in patients with a thoraco-abdominal aortic aneurysm. It is important to evaluate the artery of Adamkiewicz (AdA) before surgical repair to prevent paraplegia. But the AdA is difficult to visualize by the invasive and hazardous, conventional selective angiography. The aim of this study was to visualize AdA by MR angiography (MRA) and CT angiography (CTA). Twenty-one consecutive patients with a thoracic aortic aneurysm underwent both gadolinium-enhanced, three-dimensional MRA and CTA using multislice helical CT. The AdA was successfully visualized in 15 of the 21 patients (71.4%) by MRA, and in 17 of those 21 patients (80.9%) by CTA. Its continuity was depicted in 12 of 15 patients (80%) by MRA, and in 9 of 17 patients (47%) by CTA. AdA was visualized at 85.7% by MRA or CTA, respectively. This study shows that CTA is a much more sensitive method to detect AdA than MRA. On the other hand, MRA is better to evaluate the continuity of AdA from the descending aorta to the anterior spinal artery, than CTA. Therefore, MRA and CTA are both useful for a preoperative evaluation of AdA and its detailed vascular anatomy from the aorta to the anterior spinal artery. (author)

  6. The value of applying nitroglycerin in 3D coronary MR angiography with real-time navigation technique

    International Nuclear Information System (INIS)

    Hackenbroch, M.; Meyer, C.; Schmiedel, A.; Hofer, U.; Flacke, S.; Kovacs, A.; Schild, H.; Sommer, T.; Tiemann, K.; Skowasch, D.

    2004-01-01

    Purpose: Nitroglycerin administration results in dilation of epicardial coronary vessels and in an increase in coronary blood flow, and has been suggested to improve MR coronary angiography. This study evaluates systematically whether administration of nitroglycerin improves the visualization of coronary arteries and, as a result, the detection of coronary artery stenosis during free breathing 3D coronary MR angiography. Materials and Methods: Coronary MR angiography was performed in 44 patients with suspected coronary artery disease at a 1.5 Tesla System (Intera, Philips Medical Systems) (a) with and (b) without continuous administration of intravenous nitroglycerin at a dose rate of 2.5 mg/h, using an ECG gated gradient echo sequence with real-time navigator correction (turbo field echo, in-plane resolution 0.70 x 0.79 mm 2 , acquisition window 80 ms). Equivalent segments of the coronary arteries in the sequences with and without nitroglycerin were evaluated for visualized vessel length and diameter, qualitative assessment of visualization using a four point grading scale and detection of stenoses >50%. Catheter coronary angiography was used as a gold-standard. Results: No significant differences were found between scans with and without nitroglycerin as to average length of the contiguously visualized vessel length (p>0.05) and diameter (p>0.05). There was also no significant difference in the coronary MR angiography with and without nitroglycerin in the average qualitative assessment score of the visualization of LM, proximal LAD, proximal CX, and proximal and distal RCA (2.1±0.8 and 2.2±0.7; p> 0.05). Sensitivity (77% [17/22] vs. 82% [18/22] p>0.05) and specificity (72% [13/18] vs. 72% [13/18] p>0.05) for the detection of coronary artery stenosis also did not differ significantly between scans with and without intravenous administration of nitroglycerin. Conclusion: Administration of nitroglycerin does not improve visualization of the coronary arteries and

  7. Evaluation of renal vascular in living donors before transplantation using dynamic contrast enhanced MR angiography

    International Nuclear Information System (INIS)

    Wang Hong; Mu Xuetao; Zhong Xin; Dong Yuru; Dong Yue; Ma Yi; Wu Chunnan

    2010-01-01

    Objective: To explore whether dynamic contrast-enhanced MRA (DCE MRA) can provide an effective assessment of renal vascular in living donors before transplantation. Methods: Thirty five healthy living renal donor candidates were scanned on MR system before transplantation. After injection of Gd-DTPA 1 ml in vein, a test-bolus scan was used to get the time delay of Gd-DTPA reaching renal artery. Then, a 3D T 1 -weighted fast low-angle shot sequence (3D FLASH) was performed in the coronal plane. The 3D FLASH scan would repeat four times with an inter-phase of 10 seconds. Thus, the imaging of the renal arterial, venous and collecting systems were got. Two radiologists observed renal arteries and veins on original imaging and MIP reconstmcted imaging. The quality of MR angiography was evaluated on a five- point scale and the vascular anatomy or variations of the arterial and venous systems were recorded, using intraoperative findings as a standard of reference. Results: The quality for all MRA was good or very good for the most of living renal donors. Among 70 renals, several variations of vascular were found, including 5 left accessory artery, 9 right accessory artery, 3 left proximal arterial branch and 6 right proximal arterial branch. Among 70 renal veins, 1 right accessory veins and 2 left varicocele were observed. One small accessory artery of right kidney was missed with DCE MRA, but identified by operation. Conclusion: DCE MRA was noninvasive tool for evaluation of the renal vasculature and variations with high accuracy. It would be a good modality in preoperative evaluation of living renal donors. (authors)

  8. Variations of the posterior cerebral artery diagnosed by MR angiography at 3 tesla

    Energy Technology Data Exchange (ETDEWEB)

    Uchino, Akira; Saito, Naoko; Takahashi, Masahiro; Okano, Nanami; Tanisaka, Megumi [Saitama Medical University International Medical Center, Department of Diagnostic Radiology, Hidaka, Saitama (Japan)

    2016-02-15

    Fenestration, early bifurcation, and duplication of the posterior cerebral artery (PCA) and the so-called hyperplastic anterior choroidal artery (AChA), considered a variation of the PCA, are rare. We evaluated the prevalence and characteristic features of these PCA variations on magnetic resonance (MR) angiography. We reviewed intracranial MR angiographic images of 2402 patients examined using a 3-tesla scanner. Images from the skull base to the intracranial region were obtained using the standard time-of-flight technique. We excluded images of 52 patients with insufficient image quality or occlusion of the PCA(s) and retrospectively evaluated the images of 2350 patients using a picture archiving and communication system. We observed PCA fenestration in eight (0.34 %) patients, most at the P1 segment and P1-P2 junction and all small in size, early bifurcation at the P1-P2 junction or proximal P2A segment in eight (0.34 %) patients, complete duplication in one patient, and hyperplastic AChA in 13 (0.55 %) patients. Eleven of the 13 hyperplastic AChAs supplied only the territory of the temporal branch of the PCA, and the remaining two supplied the entire territory of the PCA. We observed PCA variations in 30 (1.28 %) patients. We believe the name ''hyperplastic AChA'' inaccurately describes variations of the PCA in which the AChA supplies part of or all of the territory of the PCA and propose ''accessory PCA'' to describe an AChA that supplies part of the territory of the PCA or ''replaced PCA'' to describe that vessel that supplies the territory all branches of the PCA. (orig.)

  9. The evaluation of three-dimensional dynamic contrast enhanced MR angiography in portal hypertension

    International Nuclear Information System (INIS)

    Wu Zhuo; Liang Biling; Liu Qingyu; Zhong Jinglian; Ye Ruixin; Ling Yunbiao; Ou Qingjia

    2006-01-01

    Objective: To evaluate the techniques of three-dimensional dynamic contrast enhanced MR angiography (3D DCE MRA)with normative timing of sequences, enhancive 3D slab thickness and subtraction in portosystemic collaterals. Methods: Before April 2003, 12 patients were performed with 75-90 mm of 3D slab thickness and 3-5 repeated sequences estimated by breath, after April 2003, 18 patients were performed with 150-180 mm of 3D slab thickness and 5 normative repeated sequences respectively at 0, 20, 40, 60 and 90 s. After subtracting selective arterial phase images from subsequent portal venous phase images, two radiologists assessed visualization of portal collaterals independently with a four - point scale for ranking of image quality in maximum intensity projection (MIP) images with and without subtraction. Results: Average scores for image quality in visualization of the portal vein with subtraction were significantly depressed compared with the scores without subtraction (2.53±0.49 versus 2.74±0.31, P<0.05). However, subtraction three dimension-maximum intensity projection (3D-MIP) gave superior visualization of portal collaterals compared with non-subtraction 3D-MIP(2.58±0.30 versus 1.63±0.50). A statistically significant difference (P<0.01) was found between the two groups of esophageal varices. Most of portosystemic shunts demonstrated in the same time as the portal vein at about 20s, but some of collaterals demonstrated in delay time. Conclusion: Subtraction 3D-MIP demonstrates portosystemic collaterals more clearly than non-subtraction; normative timing of sequences ensure against omitting varices displayed late, 3 D slab thickness provides details about paraumbilical vein and retroperitoneal collaterals. (authors)

  10. Evaluation of the early enhancement of coronary atherosclerotic plaque by contrast-enhanced MR angiography

    Energy Technology Data Exchange (ETDEWEB)

    Li Tao [Department of Radiology, The General Hospital of Chinese People' s Armed Police Forces, Number 69, Yong Ding Road, Hai Dian District, Beijing (China); Department of Radiology, Chinese People' s Liberation Army General Hospital, Number 28, Fu Xing Road, Hai Dian District, Beijing (China); Zhao Xihai [Department of Radiology, Chinese People' s Liberation Army General Hospital, Number 28, Fu Xing Road, Hai Dian District, Beijing (China); Liu Xin [Paul C. Lauterbur Biomedical Imaging Center, Institute of Biomedical and Health Engineering, Shenzhen Institute of Advanced Technology, Chinese Academy of Science, Shenzhen 518067 (China); Gao Jianhua [Department of Radiology, The General Hospital of Chinese People' s Armed Police Forces, Number 69, Yong Ding Road, Hai Dian District, Beijing (China); Zhao Shaohong [Department of Radiology, Chinese People' s Liberation Army General Hospital, Number 28, Fu Xing Road, Hai Dian District, Beijing (China); Li Xin; Zhou Weihua [Department of Radiology, The General Hospital of Chinese People' s Armed Police Forces, Number 69, Yong Ding Road, Hai Dian District, Beijing (China); Cai Zulong [Department of Radiology, Chinese People' s Liberation Army General Hospital, Number 28, Fu Xing Road, Hai Dian District, Beijing (China); Zhang Weiguo [Cardiovascular and Neurological Consulting Institute, 6771 San Fernando, Irving, TX 75039 (United States); Yang Li, E-mail: Yangli301@yahoo.com [Department of Radiology, Chinese People' s Liberation Army General Hospital, Number 28, Fu Xing Road, Hai Dian District, Beijing (China)

    2011-10-15

    Purpose: To evaluate the early enhancement of coronary atherosclerotic plaque using contrast-enhanced MR angiography (CE-MRA) and investigate the association between unstable angina pectoris (UAP) and early enhancement of the plaque. Methods: Forty-one patients presenting with angina pectoris and demonstrating single-vessel disease with non-calcified plaque and significant coronary stenosis ({>=}50%) on CTA were consecutively recruited for coronary CE-MRA. Contrast-to-noise ratio of the culprit plaque guided by CTA was measured on a cross-sectional multi-planar reconstruction image of the plaque on both pre- and post-CE-MRA. A 50% increasing of CNR was defined as plaque enhancement. The association between early enhancement of the plaques and UAP was analyzed. Results: Thirty-seven non-calcified plaques with significant coronary stenosis were detected in the 37 patients on MRA. 4 subjects were excluded because coronary atherosclerotic plaques were inadequate for identification on MRA. Of the 37 patients, 18 patients had UAP and other 19 patients presented stable angina pectoris (SAP). Of the 37 plaques on CE-MRA, 13 and 24 plaques presented early enhancement and no enhancement, respectively. Of the 13 early-enhanced plaques, 11 (85%) and 2 (15%) were found in the patients with UAP and SAP, respectively (p < 0.01). Of the 37 patients, 11 (61%) with UAP and 2 (11%) with SAP had early-enhanced plaques, respectively (p < 0.01). Conclusion: CE-MRA allows detection of early enhancement of coronary atherosclerotic plaque. The early enhancement is common in unstable angina and could be a sign of vulnerability.

  11. Evaluation of carotid vessel wall enhancement with image subtraction after gadobenate dimeglumine-enhanced MR angiography

    International Nuclear Information System (INIS)

    Sardanelli, Francesco; Di Leo, Giovanni; Aliprandi, Alberto; Flor, Nicola; Papini, Giacomo D.E.; Roccatagliata, Luca; Cotticelli, Biagio; Nano, Giovanni; Cornalba, Gianpaolo

    2009-01-01

    Objectives: This study was aimed at testing the value of image subtraction for evaluating carotid vessel wall enhancement in contrast-enhanced MR angiography (MRA). Materials and methods: IRB approval was obtained. The scans of 81 consecutive patients who underwent carotid MRA with 0.1 mmol/kg of gadobenate dimeglumine were reviewed. Axial carotid 3D T1-weighted fast low-angle shot sequence before and 3 min after contrast injection were acquired and subtracted (enhanced minus unenhanced). Vessel wall enhancement was assigned a four-point score using native or subtracted images from 0 (no enhancement) to 3 (strong enhancement). Stenosis degree was graded according to NASCET. Results: With native images, vessel wall enhancement was detected in 20/81 patients (25%) and in 20/161 carotids (12%), and scored 2.0 ± 0.6 (mean ± standard deviation); with subtracted images, in 21/81 (26%) and 22/161 (14%), and scored 2.5 ± 0.6, respectively (P < 0.001, Sign test). The overall stenosis degree distribution was: mild, 41/161 (25%); moderate, 77/161 (48%); severe, 43/161 (27%). Carotids with moderate stenosis showed vessel wall enhancement with a frequency (17/77, 22%) significantly higher than that observed in carotids with mild stenosis (1/41, 2%) (P = 0.005, Fisher exact test) and higher, even though with borderline significance (P = 0.078, Fisher exact test), than that observed in carotids with severe stenosis (4/43, 9%). Conclusion: Roughly a quarter of patients undergoing carotid MRA showed vessel wall enhancement. Image subtraction improved vessel wall enhancement conspicuity. Vessel wall enhancement seems to be an event relatively independent from the degree of stenosis. Further studies are warranted to define the relation between vessel wall enhancement and histopathology, inflammatory status, and instability.

  12. MR-Guided PTA in Experimental Bilateral Rabbit Renal Artery Stenosis and MR Angiography Follow-Up Versus Histomorphometry

    International Nuclear Information System (INIS)

    Le Blanche, Alain-Ferdinand; Rossert, Jerome; Wassef, Michel; Levy, Bernard; Bigot, Jean-Michel; Boudghene, Frank

    2000-01-01

    Purpose: To assess in vivo 1) MR-guided percutaneous transluminal renal angioplasty (PTRA) in experimental bilateral rabbit renal artery stenosis (RAS); 2) postprocedural follow-up by gadolinium-enhanced MR angiography versus histomorphometry.Methods: Fifteen male NZW rabbits of mean weight 4.0 kg (range 3.5-4.2 kg) underwent bilateral RAS induction by combined overdilation-deendothelialization with a gadolinium-filled balloon, passively MR-guided by the artifact of a 0.014-inch guidewire. After 4 weeks the rabbits were randomized into two groups: group A (n = 8) underwent right-sided PTRA for treatment of RAS, group B (n = 7) underwent left-sided PTRA. After another 4 weeks the rabbits were killed to assess by histomorphometry recurrent stenosis and contralateral induction injury stenosis lesions. Each step was preceded by gadolinium-enhanced three-dimensional MR angiography, and the cortex-to-aorta (C/A) signal intensity ratio was calculated.Results: RAS induction was successful in all cases. Fourteen arteries developed restenosis and 13 only initial stenosis. MR-guided PTRAs were feasible in 22 arteries (73%). For a successful catheterization of the ostium (20 arteries, 66% success rate), 10-25 steps were required. Five to eight steps were required for balloon localization and inflation for each PTRA. The restenosis effect was reflected by a 16% (12%-27%) decrease in C/A values on MR angiograms (p < 0.05).Conclusion: MR guidance and MR angiography represent a feasible, less invasive alternative for performing and assessing experimental PTRA in RAS

  13. The clinical value of three-dimensional contrast-enhanced MR angiography in abdominal aortic aneurysms

    International Nuclear Information System (INIS)

    Liu Qi; Lu Jianping; Tian Jianming; Wang Fei; Wang Li; Jin Aiguo; Zeng Hao; Gong Jianguo

    2004-01-01

    Objective: To evaluate the clinical value of three-dimensional contrast-enhanced MR angiography (3D CE-MRA) and its 3D reconstruction in the diagnosis of abdominal aortic aneurysms (AAA). Methods: Sixty-three patients with clinically diagnosed AAA underwent 3D CE-MRA combined with other sequences. 3D CE-MRA was performed with a 3D FISP sequence(TR, TE, FA=3.64 ms, 1.44 ms, 25 degrees, matrix=196 x 512, eff. slice=1.8 mm, FOV 30 cm x 40 cm, acquisition time=18-20 s) after injection of 0.2 mmol Gd-DTPA per kg b. w. A bolus-test was done before angiography to optimize imaging delay time. After 3D CE-MRA a T 1 -weighted sequence was acquired on the axial plane. The source images were subtracted from mask images and transferred to computer workstation, and subsequently post-processed using 3D reconstruction. All sequences were used to depict the type, location, extent, and thrombosis of the AAA, the morphology of its proximal neck, the distal aortoiliac inflow tract, and the relationship with the branches of aorta. The length, diameter, and angle of the aneurysm sac, and proximal and distal arteries were measured. The clinical role was evaluated for treatment planning. Results: High-quality 3D CE-MRA/MRI images were obtained in all patients. Among them, fifty-six had infrarenal AAA, five juxtarenal AAA, and two AAA with suprarenal extension. The mean diameter of aneurysms was 5.3 cm. The thrombosis was thicker than 2.0 cm in 26 patients. 3D CE-MRA clearly demonstrated the morphology and extent of AAA, and its proximal neck and distal aortoiliac inflow tract. The accurate parameters needed by endovascular treatment were gained simultaneously. Aneurysm and its neck depiction at 3D CE-MRA was better than that at DSA. The endovascular and surgical treatment were selected according the images (31 endovascular treatment, 4 surgical treatment, 28 conservative treatment only). The parameters at 3D CE-MRA coincided well with those at DSA in all cases (P>0.1). Conclusion: 3D CE

  14. MR angiography of the cerebral vessels with inflow-increased visualization by overcontiguous imaging and advanced processing

    International Nuclear Information System (INIS)

    McLachian, S.; Simon, H.E.; de Graaf, R.; Ho, A.M.; Ruccio, W.J.; Steidley, J.W.; Pradhan, R.B.

    1989-01-01

    The purpose of this study was to increase the visualization of cerebral vessels with MR angiography by using an inflow technique from transverse sections. Difficulties with visualization include the tortuous nature of the vessels and slow blood flow. The MR method is a transverse two-dimensional multiple single-section sequence with a velocity-compensated gradient echo and presaturation. A S15 imager with 10-mTm gradients and a prototype angiographic package is used. Overcontiguous acquisition yields smaller effective center-to-center sections. Interpolation is used to generate interleaved plane projections. A combination of image parameter swill reduce the level of the stationary tissue relative to the flowing blood. For vessels that are not perpendicular to the section, overlapping the sections by 25%--33% is shown to reduce the staircase appearance without affecting the apparent size of the vessels. Interpolation of the MR images will further reduce this artifact, giving the vessels a smooth structure. MR angiography of the brain performed with an inflow technique allows the visualization of vessels in the brain even if the vessels follow tortuous paths. Presaturation and user-defined regions of interest can be used for ease of interpretation

  15. Coronary Artery Anomalies and Variants: Technical Feasibility of Assessment with Coronary MR Angiography at 3 T1

    Science.gov (United States)

    Gharib, Ahmed M.; Ho, Vincent B.; Rosing, Douglas R.; Herzka, Daniel A.; Stuber, Matthias; Arai, Andrew E.; Pettigrew, Roderic I.

    2008-01-01

    The purpose of this study was to prospectively use a whole-heart three-dimensional (3D) coronary magnetic resonance (MR) angiography technique specifically adapted for use at 3 T and a parallel imaging technique (sensitivity encoding) to evaluate coronary arterial anomalies and variants (CAAV). This HIPAA-compliant study was approved by the local institutional review board, and informed consent was obtained from all participants. Twenty-two participants (11 men, 11 women; age range, 18–62 years) were included. Ten participants were healthy volunteers, whereas 12 participants were patients suspected of having CAAV. Coronary MR angiography was performed with a 3-T MR imager. A 3D free-breathing navigator-gated and vector electrocardiographically–gated segmented k-space gradient-echo sequence with adiabatic T2 preparation pulse and parallel imaging (sensitivity encoding) was used. Whole-heart acquisitions (repetition time msec/echo time msec, 4/1.35; 20° flip angle; 1 × 1 × 2-mm acquired voxel size) lasted 10–12 minutes. Mean examination time was 41 minutes ± 14 (standard deviation). Findings included aneurysms, ectasia, arteriovenous fistulas, and anomalous origins. The 3D whole-heart acquisitions developed for use with 3 T are feasible for use in the assessment of CAAV. © RSNA, 2008 PMID:18372470

  16. Assessment of the signal intensity distribution pattern within the unruptured cerebral aneurysms using color-coded 3D MR angiography

    International Nuclear Information System (INIS)

    Satoh, Toru; Omi, Megumi; Ohsako, Chika

    2005-01-01

    To evaluate the interaction between the MR signal intensity distribution pattern and bleb formation/deformation of the aneurysmal dome, fifty cases of the unruptured cerebral aneurysms were investigated with the color-coded 3D MR angiography. Patterns were categorized into central-type, neck-type and peripheral-type according to the distribution of MR signals with low-, moderate- and high signal intensity areas. Imaging analysis revealed the significant relationship (P<0.02) of the peripheral-type aneurysms to the bleb formation and deformation of the dome, compared with those of central- and neck-type. Additionally, peripheral-type signal intensity distribution pattern was shown with aneurysms harboring relatively large dome size and lateral-type growth including internal carotid aneurysms. Prospective analysis of intraaneurysmal flow pattern with the color-coded 3D MR angiography may provide patient-specific analysis of intraaneurysmal flow status in relation to the morphological change of the corresponding aneurysmal dome in the management of unruptured cerebral aneurysms. (author)

  17. The value of MR angiography in the diagnosis of deep vein thrombosis of the lower limbs: comparative study with DSA

    International Nuclear Information System (INIS)

    Feng Min; Wang Shuzhi; Gu Jianping; Sun Jun; Mao Cunnan; Lu Lingquan; Yin Xindao

    2007-01-01

    Objective: To assess the clinical values of MR angiography (MRA) in the detection of deep vein thrombosis of the lower limbs. Methods: Two-dimensional time of flight (2D TOF) MRA was performed in thirty patients who were suspected of having deep vein thrombosis in the lower limbs. The findings of MRA were compared to that of digital subtraction angiography (DSA). Results: twenty-five cases showed deep vein thrombosis in the lower limbs, the MRA findings included venous filling defect (14 cases), occlusions and interruptions of veins (8 cases), venous recanalizations (3 cases), collateral veins (25 cases). Taking the results of DSA as a golden standard, MRA detected all of the affected cases with only one case as the false positive. Conclusion: 2D TOF MRA is a method of choice in the diagnosis of deep vein thrombosis of the lower limbs. (authors)

  18. Usefulness of three-dimensional contrast-enhanced MR angiography in the evaluation of pelvic and lower extremity arteries

    International Nuclear Information System (INIS)

    Kim, Young Kon; Han, Young Min; Lee, Jeong Min

    2002-01-01

    To evaluate the feasibility and clinical usefulness of three-dimensional contrast-enhanced MR angiography (3D-CE-MRA) as a screening test in the evaluation of pelvic and lower extremity arterial diseases. Forty-four patients who underwent 3D-CE-MRA were included in this study. Coronal 3-dimensional gradient-echo, pre-and post contrast image were acquired with a dedicated peripheral vascular coil and moving-bed technique on a 1.5T MR system. Timing of start of data acquisition was determined by MR fluoroscopy technique, and 0.2 mmol/kg Gd-DTPA was injected into an antecubital vein, at a rate of 1cc/sec with an autoinjector. For quantitative analysis, signal to noise ratio (SNR) and artery to soft tissue contrast to noise ratio (CNR) of lower extremities arterial system including lower abdominal aorta were calculated. For qualitative analysis, arterial systems were divided into six segments, and were evaluated in terms of conspicuity of arterial systems and the degree of venous enhancement by three- and four-point scale respectively. In eight patients who underwent both MR angiography and conventional angiography as standard reference. Imaging analysis was done by means of consensus between two experienced radiologists. The mean time for the examination was about 15 min (± 5 min). The mean SNR of arterial system was 26.5±11.6, and mean artery to soft tissue contrast to noise ratio (CNR) was 24.6±11.2. Among the total 525 arterial segments 498 arterial segments (94.5%) could be demonstrated with good delineation of entire arterial tree. Good arterial imaging without or with minimal venous enhancement were demonstrated in 98.5% (260/264) in above knee and 89% (211/261) in below knee (p<0.01). Ten of 525 segments (1.9%) demonstrated severe venous overlapping and it mostly occurred in the calf region. In comparison with DSA, the sensitivity and the specificity for MR angiography for the detection of occlusions were 96% and 98.8%, respectively, and for the detection of

  19. 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

  20. Ferumoxytol as an off-label contrast agent in body 3T MR angiography: a pilot study in children

    Energy Technology Data Exchange (ETDEWEB)

    Ruangwattanapaisarn, Nichanan [Mahidol University, Department of Diagnostic and Therapeutic Radiology, Ramathibodi Hospital, Bangkok (Thailand); Stanford University, Department of Radiology, Stanford, CA (United States); Hsiao, Albert; Vasanawala, Shreyas S. [Stanford University, Department of Radiology, Stanford, CA (United States)

    2015-06-15

    Ferumoxytol is an ultrasmall superparamagnetic iron oxide (USPIO) nanoparticle agent used to treat iron deficiency anemia in adults with chronic kidney disease. We aim to determine the feasibility of using ferumoxytol for clinical pediatric cardiac and vascular imaging. We retrospectively identified 23 consecutive children who underwent MRI with ferumoxytol (11 males; mean age: 7.4 years, range: 3 days-18 years), yielding 12 abdominal MR angiography and 15 cardiac MRI studies. Medical records were reviewed for the clinical indication, ferumoxytol dose, injection rate, sedation and any complication. A two-reader consensus scored the images on a five-point scale for overall image quality and delineation of various anatomical structures. Signal-to-background ratios for abdominal aorta and inferior vena cava for abdominal cases and blood pool-myocardium contrast ratios for cardiac cases were calculated. The confidence intervals for obtaining a score of three or above for each image parameter were calculated by using adjusted Wald method. For abdominal MR angiography, average scores for overall image quality, as well as delineation of the hepatic artery, superior mesenteric artery, renal artery and veins were 4.5, 4.3, 4.3, 3.7 and 4.7, respectively. For cardiac exams, the average scores for overall image quality, systemic arteries, pulmonary arteries, pulmonary veins, valves and ventricles were 4.4, 4.6, 4.1, 4.8, 4.1 and 4.7, respectively. For all parameters, the lower bound for the proportion of cases to have a score of 3 or above was 65%. Signal-to-background ratios for aorta and abdominal veins averaged 86 +/- 74 and 86 +/- 77 for full-dose images, and 23 and 18 for half-dose images, respectively. Mean blood pool to myocardium contrast ratio was 3:3. Ferumoxytol can provide excellent image quality for pediatric body MR angiography/MR venography at a dose of 1.5 or 3 mg Fe/kg. Further investigation should be directed toward understanding the lowest dose that can be

  1. Contrast-enhanced MR angiography of abdominal vessels: Is there still a role for angiography?

    Energy Technology Data Exchange (ETDEWEB)

    Vosshenrich, R.; Fischer, U. [Department of Radiology, Georg-August-Universitaet Goettingen (Germany)

    2002-01-01

    The purpose of this review article is to describe recent advantages in contrast-enhanced (CE) three-dimensional (3D) magnetic resonance angiography (MRA) in comparison with other vascular imaging techniques, and to discuss their current clinical applications for the imaging of abdominal vessels. Principles and technical considerations are presented and clinical applications are reviewed for different vascular diseases. In ruptured aortic aneurysms and acute dissections CT is the method of first choice. Contrast-enhanced 3D MRA can be well used for therapeutic planning and follow-up in patients with stable disease. A comprehensive MR examination including CE 3D MRA, MR urography and MR nephrogram has the potential to replace the conventional studies for the evaluation of renal vascular disease. It is an accurate method for imaging the origins of coeliac and superior mesenteric arteries, although the image resolution is too low for reliable assessment of the inferior mesenteric artery. Contrast-enhanced 3D MRA has emerged as the method of choice for studying the portal venous system in liver transplant recipients, in patients with portal hypertension and in cases with abdominal tumours for preoperative evaluation. Additional non-invasive flow measurements are useful in monitoring portal hypertension. The abdominal veins can be well imaged using unenhanced MR techniques. Imaging may be facilitated with intravascular contrast media. Contrast-enhanced 3D MRA can replace intra-arterial DSA for diagnosis, therapy planning and follow-up in patients with abdominal vascular disease. Catheter-based arteriography will still be used for interventional procedures such as percutaneous transluminal angioplasty, stent placement and embolisation. (orig.)

  2. Clinical performance of a free-breathing spatiotemporally accelerated 3-D time-resolved contrast-enhanced pediatric abdominal MR angiography.

    Science.gov (United States)

    Zhang, Tao; Yousaf, Ufra; Hsiao, Albert; Cheng, Joseph Y; Alley, Marcus T; Lustig, Michael; Pauly, John M; Vasanawala, Shreyas S

    2015-10-01

    Pediatric contrast-enhanced MR angiography is often limited by respiration, other patient motion and compromised spatiotemporal resolution. To determine the reliability of a free-breathing spatiotemporally accelerated 3-D time-resolved contrast-enhanced MR angiography method for depicting abdominal arterial anatomy in young children. With IRB approval and informed consent, we retrospectively identified 27 consecutive children (16 males and 11 females; mean age: 3.8 years, range: 14 days to 8.4 years) referred for contrast-enhanced MR angiography at our institution, who had undergone free-breathing spatiotemporally accelerated time-resolved contrast-enhanced MR angiography studies. A radio-frequency-spoiled gradient echo sequence with Cartesian variable density k-space sampling and radial view ordering, intrinsic motion navigation and intermittent fat suppression was developed. Images were reconstructed with soft-gated parallel imaging locally low-rank method to achieve both motion correction and high spatiotemporal resolution. Quality of delineation of 13 abdominal arteries in the reconstructed images was assessed independently by two radiologists on a five-point scale. Ninety-five percent confidence intervals of the proportion of diagnostically adequate cases were calculated. Interobserver agreements were also analyzed. Eleven out of 13 arteries achieved acceptable image quality (mean score range: 3.9-5.0) for both readers. Fair to substantial interobserver agreement was reached on nine arteries. Free-breathing spatiotemporally accelerated 3-D time-resolved contrast-enhanced MR angiography frequently yields diagnostic image quality for most abdominal arteries in young children.

  3. Clinical performance of a free-breathing spatiotemporally accelerated 3-D time-resolved contrast-enhanced pediatric abdominal MR angiography

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Tao; Cheng, Joseph Y. [Stanford University, Department of Radiology, Stanford, CA (United States); Stanford University, Department of Electrical Engineering, Stanford, CA (United States); Yousaf, Ufra; Alley, Marcus T.; Vasanawala, Shreyas S. [Stanford University, Department of Radiology, Stanford, CA (United States); Hsiao, Albert [University of California, San Diego, Department of Radiology, San Diego, CA (United States); Lustig, Michael [Stanford University, Department of Electrical Engineering, Stanford, CA (United States); University of California, Berkeley, Department of Electrical Engineering and Computer Sciences, Berkeley, CA (United States); Pauly, John M. [Stanford University, Department of Electrical Engineering, Stanford, CA (United States)

    2015-10-15

    Pediatric contrast-enhanced MR angiography is often limited by respiration, other patient motion and compromised spatiotemporal resolution. To determine the reliability of a free-breathing spatiotemporally accelerated 3-D time-resolved contrast-enhanced MR angiography method for depicting abdominal arterial anatomy in young children. With IRB approval and informed consent, we retrospectively identified 27 consecutive children (16 males and 11 females; mean age: 3.8 years, range: 14 days to 8.4 years) referred for contrast-enhanced MR angiography at our institution, who had undergone free-breathing spatiotemporally accelerated time-resolved contrast-enhanced MR angiography studies. A radio-frequency-spoiled gradient echo sequence with Cartesian variable density k-space sampling and radial view ordering, intrinsic motion navigation and intermittent fat suppression was developed. Images were reconstructed with soft-gated parallel imaging locally low-rank method to achieve both motion correction and high spatiotemporal resolution. Quality of delineation of 13 abdominal arteries in the reconstructed images was assessed independently by two radiologists on a five-point scale. Ninety-five percent confidence intervals of the proportion of diagnostically adequate cases were calculated. Interobserver agreements were also analyzed. Eleven out of 13 arteries achieved acceptable image quality (mean score range: 3.9-5.0) for both readers. Fair to substantial interobserver agreement was reached on nine arteries. Free-breathing spatiotemporally accelerated 3-D time-resolved contrast-enhanced MR angiography frequently yields diagnostic image quality for most abdominal arteries in young children. (orig.)

  4. Clinical performance of a free-breathing spatiotemporally accelerated 3-D time-resolved contrast-enhanced pediatric abdominal MR angiography

    International Nuclear Information System (INIS)

    Zhang, Tao; Cheng, Joseph Y.; Yousaf, Ufra; Alley, Marcus T.; Vasanawala, Shreyas S.; Hsiao, Albert; Lustig, Michael; Pauly, John M.

    2015-01-01

    Pediatric contrast-enhanced MR angiography is often limited by respiration, other patient motion and compromised spatiotemporal resolution. To determine the reliability of a free-breathing spatiotemporally accelerated 3-D time-resolved contrast-enhanced MR angiography method for depicting abdominal arterial anatomy in young children. With IRB approval and informed consent, we retrospectively identified 27 consecutive children (16 males and 11 females; mean age: 3.8 years, range: 14 days to 8.4 years) referred for contrast-enhanced MR angiography at our institution, who had undergone free-breathing spatiotemporally accelerated time-resolved contrast-enhanced MR angiography studies. A radio-frequency-spoiled gradient echo sequence with Cartesian variable density k-space sampling and radial view ordering, intrinsic motion navigation and intermittent fat suppression was developed. Images were reconstructed with soft-gated parallel imaging locally low-rank method to achieve both motion correction and high spatiotemporal resolution. Quality of delineation of 13 abdominal arteries in the reconstructed images was assessed independently by two radiologists on a five-point scale. Ninety-five percent confidence intervals of the proportion of diagnostically adequate cases were calculated. Interobserver agreements were also analyzed. Eleven out of 13 arteries achieved acceptable image quality (mean score range: 3.9-5.0) for both readers. Fair to substantial interobserver agreement was reached on nine arteries. Free-breathing spatiotemporally accelerated 3-D time-resolved contrast-enhanced MR angiography frequently yields diagnostic image quality for most abdominal arteries in young children. (orig.)

  5. Variation in form on the circle of Willis as studied by 3D-TOF MR angiography

    International Nuclear Information System (INIS)

    Hoshino, Haruhiko; Takagi, Makoto; Inafuku, Tetsuya; Adachi, Tomohide; Segawa, Hiroshi

    1996-01-01

    The circles of Willis in 2011 patients were examined by 3-dimensional time-of-flight MR angiography in order to evaluate the variations. The A1 segment of the anterior cerebral artery was not found in 4.8% on the right side and in 3.4% on the left side. In the older patients, MRA failed to demonstrate either the right or left A1 segment. A fetal configuration, whereby P1 segments had a smaller diameter than the posterior communicating artery and the posterior cerebral artery derived predominantly from the carotid artery, occurred in 19.8% on the right side and in 16.7% on the left side. MRA did not reveal the posterior communicating artery to be more common in the elderly. The circulatory states in the circle of Willis may alter with aging. (author)

  6. The value of MR angiography in predicting the risk of torsion of a pelvic spleen during pregnancy

    Energy Technology Data Exchange (ETDEWEB)

    Karantanas, A.H. [Department of CT-MRI, Larissa General Hospital (Greece); Stagianis, K.D. [Department of Obstetrics and Gynecology, University Hospital, Larissa (Greece)

    2002-02-01

    A case of an enlarged pelvic spleen, studied with MRI and MR angiography (MRA), is presented in a 32-year-old female wishing to become pregnant. An ectopic located spleen may be complicated by an acute abdomen due to torsion of the splenic vascular pedicle, resulting in splenic infarction. Displacement of the spleen and splenic pedicle during pregnancy may further increase the risk of torsion. Urgent splenectomy during pregnancy is associated with a high fetal and maternal mortality and morbidity. On the other hand, elective splenectomy of a pelvic spleen before pregnancy can result in adhesion formation, compromising the patient's fertility. The abilities of MRI and MRA in predicting the risk of these life-threatening complications during pregnancy are discussed, in order to evaluate the benefit-risk ratio of surgical treatment by splenectomy of splenopexia. (orig.)

  7. The value of MR angiography in predicting the risk of torsion of a pelvic spleen during pregnancy

    International Nuclear Information System (INIS)

    Karantanas, A.H.; Stagianis, K.D.

    2002-01-01

    A case of an enlarged pelvic spleen, studied with MRI and MR angiography (MRA), is presented in a 32-year-old female wishing to become pregnant. An ectopic located spleen may be complicated by an acute abdomen due to torsion of the splenic vascular pedicle, resulting in splenic infarction. Displacement of the spleen and splenic pedicle during pregnancy may further increase the risk of torsion. Urgent splenectomy during pregnancy is associated with a high fetal and maternal mortality and morbidity. On the other hand, elective splenectomy of a pelvic spleen before pregnancy can result in adhesion formation, compromising the patient's fertility. The abilities of MRI and MRA in predicting the risk of these life-threatening complications during pregnancy are discussed, in order to evaluate the benefit-risk ratio of surgical treatment by splenectomy of splenopexia. (orig.)

  8. Poststenotic signal attenuation on 3 D phase-contrast MR angiography: a useful finding in haemodynamically significant carotid artery stenosis

    International Nuclear Information System (INIS)

    Iseda, T.; Nakano, S.; Miyahara, D.; Uchinokura, S.; Goya, T.; Wakisaka, S.

    2000-01-01

    We performed blinded visual evaluation of MR angiography (MRA) films in 44 patients with unilateral carotid artery stenosis to determine whether a flow gap and poststenotic signal attenuation on 3 D-PC MRA were useful signs of severe carotid artery stenosis. Although nine patients with a flow gap alone had various degrees of stenosis ranging from 22.2 to 77.3 % without any decrease in regional cerebral blood flow (rCBF), 13 patients with both a flow gap and poststenotic signal attenuation had severe stenoses of 80 % or more, with a definite decrease in baseline rCBF. The presence of both a flow gap and poststenotic signal attenuation on 3 D-PC MRA appeared to be a reliable marker of severe carotid artery stenosis with a decrease in rCBF. (orig.)

  9. 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.

  10. 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

  11. Diagnostic accuracy of contrast-enhanced MR angiography and unenhanced proton MR imaging compared with CT pulmonary angiography in chronic thromboembolic pulmonary hypertension

    Energy Technology Data Exchange (ETDEWEB)

    Rajaram, Smitha [Unit of Academic Radiology, University of Sheffield, Sheffield (United Kingdom); Academic Unit of Radiology, C Floor, Royal Hallamshire Hospital, Sheffield (United Kingdom); Swift, Andrew J.; Wild, Jim M. [Unit of Academic Radiology, University of Sheffield, Sheffield (United Kingdom); Sheffield Cardiovascular Biomedical Research Unit, Sheffield (United Kingdom); Capener, David; Telfer, Adam [Unit of Academic Radiology, University of Sheffield, Sheffield (United Kingdom); Davies, Christine; Hill, Catherine [Sheffield Teaching Hospitals Trust, Department of Radiology, Sheffield (United Kingdom); Condliffe, Robin; Elliot, Charles; Kiely, David G. [Sheffield Pulmonary Vascular Disease Unit, Royal Hallamshire Hospital, Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield (United Kingdom); Sheffield Cardiovascular Biomedical Research Unit, Sheffield (United Kingdom); Hurdman, Judith [Sheffield Pulmonary Vascular Disease Unit, Royal Hallamshire Hospital, Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield (United Kingdom)

    2012-02-15

    To evaluate the diagnostic accuracy of contrast-enhanced MR angiography (CE-MRA) and the added benefit of unenhanced proton MR angiography compared with CT pulmonary angiography (CTPA) in patients with chronic thromboembolic disease (CTE). A 2 year retrospective study of 53 patients with chronic thromboembolic pulmonary hypertension who underwent CTPA and MRI for suspected pulmonary hypertension and a control group of 36 patients with no CT evidence of pulmonary embolism. The MRI was evaluated for CTE and the combined diagnostic accuracy of ce-MRA and unenhanced proton MRA was determined. CE-MRA generated lung perfusion maps were also assessed. The overall sensitivity and specificity of CE-MRA in diagnosing proximal and distal CTE were 98% and 94%, respectively. The sensitivity improved from 50% to 88% for central vessel disease when CE-MRA images were analysed with unenhanced proton MRA. The CE-MRA identified more stenoses (29/18), post-stenosis dilatation (23/7) and occlusions (37/29) compared with CTPA. The CE-MRA perfusion images showed a sensitivity of 92% for diagnosing CTE. CE-MRA has high sensitivity and specificity for diagnosing CTE. The sensitivity of CE-MRA for visualisation of adherent central and lobar thrombus significantly improves with the addition of unenhanced proton MRA which delineates the vessel wall. (orig.)

  12. Diagnostic accuracy of contrast-enhanced MR angiography and unenhanced proton MR imaging compared with CT pulmonary angiography in chronic thromboembolic pulmonary hypertension

    International Nuclear Information System (INIS)

    Rajaram, Smitha; Swift, Andrew J.; Wild, Jim M.; Capener, David; Telfer, Adam; Davies, Christine; Hill, Catherine; Condliffe, Robin; Elliot, Charles; Kiely, David G.; Hurdman, Judith

    2012-01-01

    To evaluate the diagnostic accuracy of contrast-enhanced MR angiography (CE-MRA) and the added benefit of unenhanced proton MR angiography compared with CT pulmonary angiography (CTPA) in patients with chronic thromboembolic disease (CTE). A 2 year retrospective study of 53 patients with chronic thromboembolic pulmonary hypertension who underwent CTPA and MRI for suspected pulmonary hypertension and a control group of 36 patients with no CT evidence of pulmonary embolism. The MRI was evaluated for CTE and the combined diagnostic accuracy of ce-MRA and unenhanced proton MRA was determined. CE-MRA generated lung perfusion maps were also assessed. The overall sensitivity and specificity of CE-MRA in diagnosing proximal and distal CTE were 98% and 94%, respectively. The sensitivity improved from 50% to 88% for central vessel disease when CE-MRA images were analysed with unenhanced proton MRA. The CE-MRA identified more stenoses (29/18), post-stenosis dilatation (23/7) and occlusions (37/29) compared with CTPA. The CE-MRA perfusion images showed a sensitivity of 92% for diagnosing CTE. CE-MRA has high sensitivity and specificity for diagnosing CTE. The sensitivity of CE-MRA for visualisation of adherent central and lobar thrombus significantly improves with the addition of unenhanced proton MRA which delineates the vessel wall. (orig.)

  13. MR-angiography in vasculitis and benign angiopathy of the central nervous system; MR-Angiographie in der Diagnostik von Vaskulitiden und benignen Angiopathien des Zentralnervensystems

    Energy Technology Data Exchange (ETDEWEB)

    Schlueter, A.; Hirsch, W.; Jassoy, A.; Behrmann, C.; Spielmann, R.P. [Klinik fuer Diagnostische Radiologie, Martin-Luther-Univ. Halle-Wittenberg (Germany); Kornhuber, M. [Klinik fuer Neurologie, Martin-Luther-Univ. Halle-Wittenberg (Germany); Keysser, G. [Klinik fuer Innere Medizin I, Martin-Luther-Univ. Halle-Wittenberg (Germany)

    2001-06-01

    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{sub 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.) [German] Ziel der Studie war es, den Wert der TOF 3D Magnetresonanzangiographie (MRA) bei Patienten mit Vaskulitis oder vaskulitisaehnlichen, benignen Angiopathien des Zentralnervensystems (ZNS) zu erfassen. Methoden: Die MRA-Aufnahmen von 20 Patienten mit klinisch und bildgebend nachgewiesener Vaskulitis (17/20) oder vaskulitisaehnlicher, benigner Angiopathie (3/20) des ZNS wurden retrospektiv ausgewertet. Eingeschlossen wurden Patienten mit Laesionen des Hirnparenchymsgroessen 3 mm in den T{sub 2}-gewichteten Sequenzen der MRT, wobei diese Veraenderungen aufgrund umfangreicher klinischer Untersuchungen nicht auf das Vorliegen neurodegenerativer, anderweitig entzuendlicher, metastatischer oder embolischer Ursachen zurueckzufuehren waren. Fuer die MRA wurde eine TOF 3D FISP-Sequenz auf einem 1,5T MR-Geraet verwendet. Ergebnisse: MR-angiographisch wurden bei 15/20 Patienten (75

  14. Image quality and diagnostic accuracy of unenhanced SSFP MR angiography compared with conventional contrast-enhanced MR angiography for the assessment of thoracic aortic diseases

    Energy Technology Data Exchange (ETDEWEB)

    Krishnam, Mayil S. [University of California, Cardiovascular and Thoracic Imaging, UCI Medical Center, Irvine, CA (United States); Tomasian, Anderanik; Malik, Sachin; Ruehm, Stefan G. [University of California at Los Angeles, Department of Radiological Sciences, Ronald Reagan Medical Center, Los Angeles, CA (United States); Desphande, Vibhas; Laub, Gerhard [Siemens Medical Solutions, Los Angeles, CA (United States)

    2010-06-15

    The purpose of this study was to determine the image quality and diagnostic accuracy of three-dimensional (3D) unenhanced steady state free precession (SSFP) magnetic resonance angiography (MRA) for the evaluation of thoracic aortic diseases. Fifty consecutive patients with known or suspected thoracic aortic disease underwent free-breathing ECG-gated unenhanced SSFP MRA with non-selective radiofrequency excitation and contrast-enhanced (CE) MRA of the thorax at 1.5 T. Two readers independently evaluated the two datasets for image quality in the aortic root, ascending aorta, aortic arch, descending aorta, and origins of supra-aortic arteries, and for abnormal findings. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were determined for both datasets. Sensitivity, specificity, and diagnostic accuracy of unenhanced SSFP MRA for the diagnosis of aortic abnormalities were determined. Abnormal aortic findings, including aneurysm (n = 47), coarctation (n = 14), dissection (n = 12), aortic graft (n = 6), intramural hematoma (n = 11), mural thrombus in the aortic arch (n = 1), and penetrating aortic ulcer (n = 9), were confidently detected on both datasets. Sensitivity, specificity, and diagnostic accuracy of SSFP MRA for the detection of aortic disease were 100% with CE-MRA serving as a reference standard. Image quality of the aortic root was significantly higher on SSFP MRA (P < 0.001) with no significant difference for other aortic segments (P > 0.05). SNR and CNR values were higher for all segments on SSFP MRA (P < 0.01). Our results suggest that free-breathing navigator-gated 3D SSFP MRA with non-selective radiofrequency excitation is a promising technique that provides high image quality and diagnostic accuracy for the assessment of thoracic aortic disease without the need for intravenous contrast material. (orig.)

  15. Image quality and diagnostic accuracy of unenhanced SSFP MR angiography compared with conventional contrast-enhanced MR angiography for the assessment of thoracic aortic diseases

    International Nuclear Information System (INIS)

    Krishnam, Mayil S.; Tomasian, Anderanik; Malik, Sachin; Ruehm, Stefan G.; Desphande, Vibhas; Laub, Gerhard

    2010-01-01

    The purpose of this study was to determine the image quality and diagnostic accuracy of three-dimensional (3D) unenhanced steady state free precession (SSFP) magnetic resonance angiography (MRA) for the evaluation of thoracic aortic diseases. Fifty consecutive patients with known or suspected thoracic aortic disease underwent free-breathing ECG-gated unenhanced SSFP MRA with non-selective radiofrequency excitation and contrast-enhanced (CE) MRA of the thorax at 1.5 T. Two readers independently evaluated the two datasets for image quality in the aortic root, ascending aorta, aortic arch, descending aorta, and origins of supra-aortic arteries, and for abnormal findings. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were determined for both datasets. Sensitivity, specificity, and diagnostic accuracy of unenhanced SSFP MRA for the diagnosis of aortic abnormalities were determined. Abnormal aortic findings, including aneurysm (n = 47), coarctation (n = 14), dissection (n = 12), aortic graft (n = 6), intramural hematoma (n = 11), mural thrombus in the aortic arch (n = 1), and penetrating aortic ulcer (n = 9), were confidently detected on both datasets. Sensitivity, specificity, and diagnostic accuracy of SSFP MRA for the detection of aortic disease were 100% with CE-MRA serving as a reference standard. Image quality of the aortic root was significantly higher on SSFP MRA (P 0.05). SNR and CNR values were higher for all segments on SSFP MRA (P < 0.01). Our results suggest that free-breathing navigator-gated 3D SSFP MRA with non-selective radiofrequency excitation is a promising technique that provides high image quality and diagnostic accuracy for the assessment of thoracic aortic disease without the need for intravenous contrast material. (orig.)

  16. Peripheral Vasculature: High-Temporal- and High-Spatial-Resolution Three-dimensional Contrast-enhanced MR Angiography1

    Science.gov (United States)

    Haider, Clifton R.; Glockner, James F.; Stanson, Anthony W.; Riederer, Stephen J.

    2009-01-01

    Purpose: To prospectively evaluate the feasibility of performing high-spatial-resolution (1-mm isotropic) time-resolved three-dimensional (3D) contrast material–enhanced magnetic resonance (MR) angiography of the peripheral vasculature with Cartesian acquisition with projection-reconstruction–like sampling (CAPR) and eightfold accelerated two-dimensional (2D) sensitivity encoding (SENSE). Materials and Methods: All studies were approved by the institutional review board and were HIPAA compliant; written informed consent was obtained from all participants. There were 13 volunteers (mean age, 41.9; range, 27–53 years). The CAPR sequence was adapted to provide 1-mm isotropic spatial resolution and a 5-second frame time. Use of different receiver coil element sizes for those placed on the anterior-to-posterior versus left-to-right sides of the field of view reduced signal-to-noise ratio loss due to acceleration. Results from eight volunteers were rated independently by two radiologists according to prominence of artifact, arterial to venous separation, vessel sharpness, continuity of arterial signal intensity in major arteries (anterior and posterior tibial, peroneal), demarcation of origin of major arteries, and overall diagnostic image quality. MR angiographic results in two patients with peripheral vascular disease were compared with their results at computed tomographic angiography. Results: The sequence exhibited no image artifact adversely affecting diagnostic image quality. Temporal resolution was evaluated to be sufficient in all cases, even with known rapid arterial to venous transit. The vessels were graded to have excellent sharpness, continuity, and demarcation of the origins of the major arteries. Distal muscular branches and the communicating and perforating arteries were routinely seen. Excellent diagnostic quality rating was given for 15 (94%) of 16 evaluations. Conclusion: The feasibility of performing high-diagnostic-quality time-resolved 3D

  17. The accuracy and utility of contrast-enhanced MR angiography for localization of spinal dural arteriovenous fistulas: the Toronto experience

    Energy Technology Data Exchange (ETDEWEB)

    Lindenholz, Arjen [University Medical Center Groningen, Department of Neurosurgery AB71, PO Box 30001, Groningen (Netherlands); Toronto Western Hospital, Department of Medical Imaging, Division of Neuroradiology, Toronto, ON (Canada); TerBrugge, Karel G.; Farb, Richard I. [Toronto Western Hospital, Department of Medical Imaging, Division of Neuroradiology, Toronto, ON (Canada); Dijk, J.M.C. van [University Medical Center Groningen, Department of Neurosurgery AB71, PO Box 30001, Groningen (Netherlands)

    2014-11-15

    The purpose of this study was to determine the accuracy and utility of contrast-enhanced MR angiography (CE-MRA) in spinal dural arteriovenous fistulas (SDAVF). A retrospective analysis from 1999-2012 identified 70 patients clinically suspected of harboring a SDAVF. Each patient underwent consecutive conventional MR-imaging, CE-MRA, and digital subtraction angiography (DSA). The presence or absence of serpentine flow voids, T2-weighted hyperintensity, and cord enhancement were evaluated, as well as location of the fistula as predicted by CE-MRA. DSA was used as the reference standard. Of the 70 cases, 53 were determined to be a SDAVF, 10 cases were shown to be other forms of vascular malformation, and 7 were DSA-negative. On MRI, all reported cases of SDAVF showed serpentine flow voids (100 %). T2-weighted hyperintensity was seen in 48 of 50 cases (96 %), extending to the conus in 41 of 48 cases (85 %). Cord enhancement was seen in 38 of 41 cases (93 %). CE-MRA correctly localized the SDAVF in 43 of the 53 cases (81 %). CE-MRA is a useful non-invasive examination for the detection and localization of SDAVF. CE-MRA facilitates but does not replace DSA as confirmation of location, fistula type, and arterial detail, which are required before treatment. (orig.)

  18. MR angiography in the follow-up of coiled cerebral aneurysms after treatment with Guglielmi detachable coils

    International Nuclear Information System (INIS)

    Nome, T.; Bakke, S. J.; Nakstad, P. H.

    2002-01-01

    Purpose: Intra-arterial digital subtraction angiography (DSA) has been considered the gold standard examination in the follow-up of patients treated with Guglielmi detachable coils (GDCs). However, DSA is an invasive and expensive investigation and results in exposure to ionising radiation to both patient and operator. The aim of this study was to compare MR angiography (MRA) with DSA with regard to patency of the occlusion of aneurysms following GDC treatment. Material and Methods: We performed 75 MRA and DSA examinations on 51 patients treated with GDCs. The examinations were performed 3-36 months after embolisation and the interval between MRA and DSA was less than 1 week. Hard copies of both studies were interpreted retrospectively and independently for residual flow within the aneurysm, residual aneurysmal neck, and parent and branch vessel flow. Results: Patency status of parent and branch vessel flow was correctly identified with MRA in all patients except 1. The sensitivity of MRA in revealing residual flow within the aneurysm was 97%. The specificity in ruling out residual flow within the aneurysm was 91%. Conclusion: MRA may replace DSA in the long-term follow-up of coiled cerebral aneurysms. The initial follow-up examination should, however, include both modalities

  19. Assessment of chronic thromboembolic pulmonary hypertension by three-dimensional contrast-enhanced MR angiography - comparison with selective intraarterial DSA

    International Nuclear Information System (INIS)

    Kreitner, K.F.; Ley, S.; Kauczor, H.U.; Kalden, P.; Pitton, M.B.; Thelen, M.; Mayer, E.; Laub, G.

    2000-01-01

    Purpose: This study compares contrast-enhanced 3D-MR angiography (MRA) of the pulmonary arteries with selective intraarterial DSA in patients with chronic thromboembolic pulmonary hypertension. Materials and methods: 20 patients preoperatively underwent a contrast-enhanced 3D-MRA of the pulmonary arteries at 1.5 T using the phased-array body coil. For MRA, we used a 3D-Flash-sequence after bolus timing. 2 radiologists analyzed the acquired image material in consensus with respect to the detection of central thromboembolic material and the visualization of the pulmonary arterial tree. Finally, the MR angiograms were compared with selective DSA images using surgical findings as the definitive standard. Results: MRA demonstrated central thromboembolic material, vessel cut-offs and abnormal proximal-to-distal tapering in all patients. Compared to DSA, MRA depicted the pulmonary vessels up to the segmental level in all cases, it was inferior to DSA in delineation of the subsegmental arteries (sensitivity 87%, specificity 100%). The central beginning of the thromboembolic occlusions seen at MRA corresponded to the beginning of the deobliteration procedure during pulmonary thromboendarterectomy in every case. (orig.) [de

  20. Pancreatic adenocarcinoma: combination of MR imaging, MR angiography and MR cholangiopancreatography for the diagnosis and assessment of resectability

    International Nuclear Information System (INIS)

    Catalano, C.; Pavone, P.; Laghi, A.; Panebianco, V.; Scipioni, A.; Fanelli, F.; Brillo, R.; Passariello, R.

    1998-01-01

    The purpose of this study was to determine the possibility of integrating MR cholangiopancreatography (MRCP) and MR angiography (MRA) to conventional MR images in the diagnosis and assessment of resectability of pancreatic adenocarcinoma. Twenty-three patients with pancreatic adenocarcinoma were prospectively examined with MR. Conventional MR images were acquired in all patients. Three-dimensional MRCP and MRA images were acquired in all patients with suspected biliary and vascular involvement. Acquisition time was less than 45 min in all cases. Images were independently evaluated by two radiologists, with final reading decided by consensus among readers. Diagnosis was confirmed with surgery in 16 patients and with percutaneous biopsy in 7. Concordance among readers was high with a kappa value of 0.83. Pancreatic adenocarcinoma was observed in all patients. Correct assessment of unresectability due to vascular involvement was found in 22 of 23 patients. Biliary obstruction was evident in 13 patients, involving the biliary and pancreatic ducts in 9 and the biliary ducts only in 4. Technical advances permit extensive use of MRI in the evaluation of abdominal pathologies. The combination of MR imaging, MRCP, and MRA can provide sufficient information for the diagnosis and assessment of resectability of pancreatic adenocarcinoma, which otherwise would require three different exams. (orig.)

  1. Time of flight MR angiography assessment casts doubt on the association between transient global amnesia and intracranial jugular venous reflux

    International Nuclear Information System (INIS)

    Kang, Yeonah; Kim, Eunhee; Kim, Jae Hyoung; Choi, Byung Se; Jung, Cheolkyu; Bae, Yun Jung; Lee, Kyung Mi; Lee, Dong Hoon

    2015-01-01

    Evidence of intracranial venous reflux flow due to jugular venous reflux (JVR) on time of flight (TOF) MR angiography (MRA) is thought to be highly associated with transient global amnesia (TGA) - evidence that supports the venous congestion theory of TGA pathophysiology. However, recent studies indicate that intracranial JVR on TOF MRA is occasionally observed in normal elderly. Therefore, the purpose of this study was to compare the prevalence of intracranial JVR on TOF MRA in patients with TGA and two control groups. Three age- and sex-matched groups of subjects that received MRI and MRA were enrolled. The groups comprised 167 patients with TGA, 167 visitors to the emergency room (ER) and 167 visitors to a health promotion centre (HPC). Intracranial JVR was defined as abnormal venous signals in the inferior petrosal, sigmoid and/or transverse sinuses on TOF MRA. The prevalence of intracranial JVR was assessed across the three groups. Intracranial JVR was seen in seven (4.2 %) TGA patients, eight (4.8 %) ER visitors and three (1.8 %) HPC visitors, respectively. No statistically significant differences were observed among the three groups. TGA patients showed a low prevalence of intracranial JVR on TOF MRA, and no statistical differences were found in comparison with control groups. (orig.)

  2. Evaluation of Contrast MR Angiography in the Study of Internal Carotid Artery Stenosis. Systematic Review of the Literature

    International Nuclear Information System (INIS)

    Rodriguez Perez, P.; Martinez Cantarero, J.; Ruiz Diaz, M.; Blazquez Morera, J. A.; Llano Senaris, J. E. de

    2004-01-01

    To evaluate the diagnostic benefit of using contrast MR Angiography (MRA) in the study of extracranial internal carotid artery stenosis as opposed to intraarterial digital subtraction arteriography (LADSA). A search for relevant articles from 1990 to 2000 using MDLINE and EMBASE databases. Initial selection criteria: 1. articles which compare MRA and IADSA in the study of extracranial internal carotid artery stenosis; and 2, sample size of 10 or more subjects. Studies employing contrast MRA were subsequently selected. Contrast MRA diagnostic results were studied, as were those of non-contrast MRA (TOF) if included. Roc curves and 95% confidence intervals were calculated. In the studies, 324 patients and 648 extracranial internal carotid arteries were evaluated (12 articles). The diagnostic results in carotid artery stenosis discrimination using contrast MRA as opposed to IADSA were sensitivity and specificity=97.28% and 96.08%. With regard to contrast MRA vs. non-contrast MRA (TOF), significant differences favoring contrast MRA in both sensitivity and specificity were observed. (p=0.08 and p<0.001, respectively). MRA techniques demonstrate very high diagnostic capabilities in the detection of carotid stenosis, with contrast MRA being more effective than non-contrast. MRA. In spite of not being superior to IADSA, given the morbimortality risk which the latter is associated (0.7-1.2%). many authors defend contrast MRA (in association with Doppler echography) having become the method of choice for presurgical study of extracranial internal carotid artery stenosis. (Author) 53 refs

  3. Towards risk stratification in systemic atherosclerosis: value of myocardial function and viability imaging as an adjunct to MR angiography

    Energy Technology Data Exchange (ETDEWEB)

    Seeger, Achim; Fenchel, Michael; Kramer, Ulrich; Bretschneider, Christiane; Grimm, Florian; Klumpp, Bernhard; Claussen, Claus D.; Miller, Stephan [Eberhard Karls University Tuebingen, Department of Diagnostic and Interventional Radiology, Tuebingen (Germany); Scheule, Albertus [Eberhard Karls University Tuebingen, Department for Thorax, Cardiac and Vascular Surgery, Tuebingen (Germany); Balletshofer, Bernd [Eberhard Karls University Tuebingen, Department of Internal Medicine IV, Tuebingen (Germany)

    2010-04-15

    To longitudinally assess the value of cardiac functional and viability imaging as a supplement to MR angiography in patients with atherosclerotic disease. Cardiac MRI was performed in 195 consecutive patients with symptomatic peripheral arterial disease. Of these, 186 patients were followed for 22 {+-} 5 months for the presence of cardiac events (cardiac death, acute coronary syndrome and hospitalisation as a result of congestive heart failure). Myocardial viability imaging showed a high prevalence of known (n = 31) and occult myocardial infarctions (MI) (n = 26). Cardiac events occurred more often in patients with reduced ventricular function (ejection fraction (EF) less than 40%, cardiac event in 4/8 patients; EF 40-55%, cardiac event in 10/40 patients; EF greater than 55%, cardiac event in 15/138 patients) as well as in patients with occult MI (8/25 patients) and known MI (11/30 patients). In patients with normal function, the detection of a previous MI was of high relevance to prognosis. Both reduced EF and the presence of MI influence patients' prognoses. Performing cardiac MRI in this patient population may influence further patient management including intensified risk factor intervention. (orig.)

  4. Validation of new 3D post processing algorithm for improved maximum intensity projections of MR angiography acquisitions in the brain

    Energy Technology Data Exchange (ETDEWEB)

    Bosmans, H; Verbeeck, R; Vandermeulen, D; Suetens, P; Wilms, G; Maaly, M; Marchal, G; Baert, A L [Louvain Univ. (Belgium)

    1995-12-01

    The objective of this study was to validate a new post processing algorithm for improved maximum intensity projections (mip) of intracranial MR angiography acquisitions. The core of the post processing procedure is a new brain segmentation algorithm. Two seed areas, background and brain, are automatically detected. A 3D region grower then grows both regions towards each other and this preferentially towards white regions. In this way, the skin gets included into the final `background region` whereas cortical blood vessels and all brain tissues are included in the `brain region`. The latter region is then used for mip. The algorithm runs less than 30 minutes on a full dataset on a Unix workstation. Images from different acquisition strategies including multiple overlapping thin slab acquisition, magnetization transfer (MT) MRA, Gd-DTPA enhanced MRA, normal and high resolution acquisitions and acquisitions from mid field and high field systems were filtered. A series of contrast enhanced MRA acquisitions obtained with identical parameters was filtered to study the robustness of the filter parameters. In all cases, only a minimal manual interaction was necessary to segment the brain. The quality of the mip was significantly improved, especially in post Gd-DTPA acquisitions or using MT, due to the absence of high intensity signals of skin, sinuses and eyes that otherwise superimpose on the angiograms. It is concluded that the filter is a robust technique to improve the quality of MR angiograms.

  5. Max CAPR: high-resolution 3D contrast-enhanced MR angiography with acquisition times under 5 seconds.

    Science.gov (United States)

    Haider, Clifton R; Borisch, Eric A; Glockner, James F; Mostardi, Petrice M; Rossman, Phillip J; Young, Phillip M; Riederer, Stephen J

    2010-10-01

    High temporal and spatial resolution is desired in imaging of vascular abnormalities having short arterial-to-venous transit times. Methods that exploit temporal correlation to reduce the observed frame time demonstrate temporal blurring, obfuscating bolus dynamics. Previously, a Cartesian acquisition with projection reconstruction-like (CAPR) sampling method has been demonstrated for three-dimensional contrast-enhanced angiographic imaging of the lower legs using two-dimensional sensitivity-encoding acceleration and partial Fourier acceleration, providing 1mm isotropic resolution of the calves, with 4.9-sec frame time and 17.6-sec temporal footprint. In this work, the CAPR acquisition is further undersampled to provide a net acceleration approaching 40 by eliminating all view sharing. The tradeoff of frame time and temporal footprint in view sharing is presented and characterized in phantom experiments. It is shown that the resultant 4.9-sec acquisition time, three-dimensional images sets have sufficient spatial and temporal resolution to clearly portray arterial and venous phases of contrast passage. It is further hypothesized that these short temporal footprint sequences provide diagnostic quality images. This is tested and shown in a series of nine contrast-enhanced MR angiography patient studies performed with the new method.

  6. Three-dimensional coronary MR angiography with continuous administration of Gd-DTPA. Delineation and detection of coronary artery stenosis

    International Nuclear Information System (INIS)

    Yokoyama, Kenichi

    1999-01-01

    Three-dimensional coronary MR angiography (3D coronary MRA) with Gd-DTPA administration was performed in 19 patients to evaluate the vascular delineation and diagnostic capability for stenotic lesions. A 3D fast low-angle shot (FLASH) with a navigator echo respiratory gating technique was used with a superconducting 1.5 tesla MR system (Vision, Siemens Medical Systems, Erlangen, Germany). Administration of the conventional T 1 contrast agent with extra-cellular distribution produced a significant increase in the SNR and CNR of the proximal coronary arterial images. Visual score of both the source images and the multiplanar reconstruction (MPR) images assessed by three radiologists was superior to those on control images (without contrast enhancement). The MRA findings of stenotic lesions of the coronary artery were compared with the results of the conventional coronary angiographic study. Overall sensitivity and specificity for the detection of stenosis were almost the same as those of control images. In conclusion, 3D coronary MRA with Gd-DTPA administration improved coronary artery delineation. However, further technical improvements are required to enhance the value of the technique in detecting stenoses. (author)

  7. Differential diagnosis of benign and malignant intraductal papillary mucinous tumors of the pancreas: MR cholangiopancreatography and MR angiography

    International Nuclear Information System (INIS)

    Choi, Byung Se; Kim, Tae Kyoung; Kim, Ah Young; Kim, Kyoung Won; Park, Sung Won; Kim, Pyo Nyun; Ha, Kyun Kwon; Lee, Moon Gyu; Kim, Song Cheol

    2003-01-01

    To compare the usefulness of magnetic resonance cholangiopancreatography (MRCP) and MR angiography (MRA) in differentiating malignant from benign intraductal papillary mucinous tumors of the pancreas (IPMTs), and to determine the findings which suggest malignancy. During a 6-year period, 46 patients with IPMT underwent MRCP. Morphologically, tumor type was classified as main duct, branch duct, or combined. The diameter of the main pancreatic duct (MPD), the extent of the dilated MPD, and the location and size of the cystic lesion, septum, and communicating channel were assessed. For all types of IPMTs, enhanced mural nodules and portal vein narrowing were evaluated at MRA. Combined-type IPMTs were more frequently malignant (78%) than benign (42%) (p<0.05). Compared with benign lesions, malignant lesions were larger, and the caliber of the communicating channel was also larger (p < 0.05). Their dilated MPD was more extensive and of greater diameter (p<0.05), and the presence of mural nodules was more frequent (p<0.001). Combined MRCP and MRA might be useful for the differential diagnosis of malignant and benign IPMTs of the pancreas

  8. Contrast-enhanced 3D MR angiography of the chest and abdomen with breath-holding using phase reordering

    International Nuclear Information System (INIS)

    Amanuma, Makoto; Sugimoto, Eiichi; Enomoto, Kyoko; Watabe, Tsuneya; Heshiki, Atsuko; Hirata, Hisashi; Kimura, Toshihiko; Takizawa, Osamu.

    1995-01-01

    This report presents the feasibility of phase-reordered contrast-enhanced three-dimensional MR angiography in 32 consecutive patients with vascular abnormalities in the chest and abdomen. To suppress motion artifacts due to respiratory corruption, a phase-reordering technique was introduced so that the low frequency components of the phase data were obtained first during the imaging period. Image quality and degree of motion suppression were assessed by four radiologists independently without information on breath-holding time. Abnormalities were detected in 30 cases (93.8%), and their extent was correctly assessed in 28 cases (87.5%). More confident assessment was possible in abnormalities of the pulmonary vessels and thoracic aorta than in those of the abdominal aorta and portal venous system. With phase reordering, more than 20 seconds of breath-holding ensured image quality sufficient to correctly assess the vascular abnormalities. While this technique is easy and requires only single breath-holding, it can provide excellent MRA without slice-to-slice spatial misregistration. (author)

  9. Evaluation of fast highly undersampled contrast-enhanced MR angiography (sparse CE-MRA) in intracranial applications - initial study

    International Nuclear Information System (INIS)

    Gratz, Marcel; Quick, Harald H.; Schlamann, Marc; Goericke, Sophia; Maderwald, Stefan

    2017-01-01

    To assess the image quality of sparsely sampled contrast-enhanced MR angiography (sparse CE-MRA) providing high spatial resolution and whole-head coverage. Twenty-three patients scheduled for contrast-enhanced MR imaging of the head, (N = 19 with intracranial pathologies, N = 9 with vascular diseases), were included. Sparse CE-MRA at 3 Tesla was conducted using a single dose of contrast agent. Two neuroradiologists independently evaluated the data regarding vascular visibility and diagnostic value of overall 24 parameters and vascular segments on a 5-point ordinary scale (5 = very good, 1 = insufficient vascular visibility). Contrast bolus timing and the resulting arterio-venous overlap was also evaluated. Where available (N = 9), sparse CE-MRA was compared to intracranial Time-of-Flight MRA. The overall rating across all patients for sparse CE-MRA was 3.50 ± 1.07. Direct influence of the contrast bolus timing on the resulting image quality was observed. Overall mean vascular visibility and image quality across different features was rated good to intermediate (3.56 ± 0.95). The average performance of intracranial Time-of-Flight was rated 3.84 ± 0.87 across all patients and 3.54 ± 0.62 across all features. Sparse CE-MRA provides high-quality 3D MRA with high spatial resolution and whole-head coverage within short acquisition time. Accurate contrast bolus timing is mandatory. (orig.)

  10. Towards risk stratification in systemic atherosclerosis: value of myocardial function and viability imaging as an adjunct to MR angiography

    International Nuclear Information System (INIS)

    Seeger, Achim; Fenchel, Michael; Kramer, Ulrich; Bretschneider, Christiane; Grimm, Florian; Klumpp, Bernhard; Claussen, Claus D.; Miller, Stephan; Scheule, Albertus; Balletshofer, Bernd

    2010-01-01

    To longitudinally assess the value of cardiac functional and viability imaging as a supplement to MR angiography in patients with atherosclerotic disease. Cardiac MRI was performed in 195 consecutive patients with symptomatic peripheral arterial disease. Of these, 186 patients were followed for 22 ± 5 months for the presence of cardiac events (cardiac death, acute coronary syndrome and hospitalisation as a result of congestive heart failure). Myocardial viability imaging showed a high prevalence of known (n = 31) and occult myocardial infarctions (MI) (n = 26). Cardiac events occurred more often in patients with reduced ventricular function (ejection fraction (EF) less than 40%, cardiac event in 4/8 patients; EF 40-55%, cardiac event in 10/40 patients; EF greater than 55%, cardiac event in 15/138 patients) as well as in patients with occult MI (8/25 patients) and known MI (11/30 patients). In patients with normal function, the detection of a previous MI was of high relevance to prognosis. Both reduced EF and the presence of MI influence patients' prognoses. Performing cardiac MRI in this patient population may influence further patient management including intensified risk factor intervention. (orig.)

  11. Time of flight MR angiography assessment casts doubt on the association between transient global amnesia and intracranial jugular venous reflux

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Yeonah; Kim, Eunhee; Kim, Jae Hyoung; Choi, Byung Se; Jung, Cheolkyu; Bae, Yun Jung; Lee, Kyung Mi [Seoul National University College of Medicine, Seoul National University Bundang Hospital, Department of Radiology, Seongnam-si, Gyeonggi-do (Korea, Republic of); Lee, Dong Hoon [Seoul Medical Center, Department of Radiology, Seoul (Korea, Republic of)

    2014-10-03

    Evidence of intracranial venous reflux flow due to jugular venous reflux (JVR) on time of flight (TOF) MR angiography (MRA) is thought to be highly associated with transient global amnesia (TGA) - evidence that supports the venous congestion theory of TGA pathophysiology. However, recent studies indicate that intracranial JVR on TOF MRA is occasionally observed in normal elderly. Therefore, the purpose of this study was to compare the prevalence of intracranial JVR on TOF MRA in patients with TGA and two control groups. Three age- and sex-matched groups of subjects that received MRI and MRA were enrolled. The groups comprised 167 patients with TGA, 167 visitors to the emergency room (ER) and 167 visitors to a health promotion centre (HPC). Intracranial JVR was defined as abnormal venous signals in the inferior petrosal, sigmoid and/or transverse sinuses on TOF MRA. The prevalence of intracranial JVR was assessed across the three groups. Intracranial JVR was seen in seven (4.2 %) TGA patients, eight (4.8 %) ER visitors and three (1.8 %) HPC visitors, respectively. No statistically significant differences were observed among the three groups. TGA patients showed a low prevalence of intracranial JVR on TOF MRA, and no statistical differences were found in comparison with control groups. (orig.)

  12. Validation of new 3D post processing algorithm for improved maximum intensity projections of MR angiography acquisitions in the brain

    International Nuclear Information System (INIS)

    Bosmans, H.; Verbeeck, R.; Vandermeulen, D.; Suetens, P.; Wilms, G.; Maaly, M.; Marchal, G.; Baert, A.L.

    1995-01-01

    The objective of this study was to validate a new post processing algorithm for improved maximum intensity projections (mip) of intracranial MR angiography acquisitions. The core of the post processing procedure is a new brain segmentation algorithm. Two seed areas, background and brain, are automatically detected. A 3D region grower then grows both regions towards each other and this preferentially towards white regions. In this way, the skin gets included into the final 'background region' whereas cortical blood vessels and all brain tissues are included in the 'brain region'. The latter region is then used for mip. The algorithm runs less than 30 minutes on a full dataset on a Unix workstation. Images from different acquisition strategies including multiple overlapping thin slab acquisition, magnetization transfer (MT) MRA, Gd-DTPA enhanced MRA, normal and high resolution acquisitions and acquisitions from mid field and high field systems were filtered. A series of contrast enhanced MRA acquisitions obtained with identical parameters was filtered to study the robustness of the filter parameters. In all cases, only a minimal manual interaction was necessary to segment the brain. The quality of the mip was significantly improved, especially in post Gd-DTPA acquisitions or using MT, due to the absence of high intensity signals of skin, sinuses and eyes that otherwise superimpose on the angiograms. It is concluded that the filter is a robust technique to improve the quality of MR angiograms

  13. Evaluation of fast highly undersampled contrast-enhanced MR angiography (sparse CE-MRA) in intracranial applications - initial study

    Energy Technology Data Exchange (ETDEWEB)

    Gratz, Marcel; Quick, Harald H. [University of Duisburg-Essen, Erwin L. Hahn Institute for MR Imaging, Essen (Germany); University Hospital Essen, High Field and Hybrid MR Imaging, Essen (Germany); Schlamann, Marc [University Hospital Giessen and Marburg GmbH, Neuroradiology, Giessen (Germany); University Hospital Essen, Department of Diagnostic and Interventional Radiology and Neuroradiology, Essen (Germany); Goericke, Sophia [University Hospital Essen, Department of Diagnostic and Interventional Radiology and Neuroradiology, Essen (Germany); Maderwald, Stefan [University of Duisburg-Essen, Erwin L. Hahn Institute for MR Imaging, Essen (Germany)

    2017-03-15

    To assess the image quality of sparsely sampled contrast-enhanced MR angiography (sparse CE-MRA) providing high spatial resolution and whole-head coverage. Twenty-three patients scheduled for contrast-enhanced MR imaging of the head, (N = 19 with intracranial pathologies, N = 9 with vascular diseases), were included. Sparse CE-MRA at 3 Tesla was conducted using a single dose of contrast agent. Two neuroradiologists independently evaluated the data regarding vascular visibility and diagnostic value of overall 24 parameters and vascular segments on a 5-point ordinary scale (5 = very good, 1 = insufficient vascular visibility). Contrast bolus timing and the resulting arterio-venous overlap was also evaluated. Where available (N = 9), sparse CE-MRA was compared to intracranial Time-of-Flight MRA. The overall rating across all patients for sparse CE-MRA was 3.50 ± 1.07. Direct influence of the contrast bolus timing on the resulting image quality was observed. Overall mean vascular visibility and image quality across different features was rated good to intermediate (3.56 ± 0.95). The average performance of intracranial Time-of-Flight was rated 3.84 ± 0.87 across all patients and 3.54 ± 0.62 across all features. Sparse CE-MRA provides high-quality 3D MRA with high spatial resolution and whole-head coverage within short acquisition time. Accurate contrast bolus timing is mandatory. (orig.)

  14. Dynamic 3D-MR-angiography for assessing rheumatoid disease of the hand—A feasibility study

    International Nuclear Information System (INIS)

    Notohamiprodjo, Mike; Glaser, Christian; Horng, Annie; Helck, Andreas; Bauner, Kerstin U.; Reiser, Maximilian F.; Hatz, Hans J.; Weckbach, Sabine

    2012-01-01

    Purpose: To investigate highly temporally resolved MR-angiography (MRA) with time-resolved imaging with stochastic trajectories (TWIST) of the hand as supplementary tool for dynamic assessment of synovitis and vascular pathologies in rheumatoid diseases. Material and methods: A coronal dynamic TWIST–MRA-sequence (0.7 mm × 0.7 mm × 1.4 mm, temporal resolution 2.5 s, time of acquisition 4 min) of the predominantly affected hand of 17 patients with suspected rheumatoid disease was acquired after contrast administration (Multihance, Bracco Imaging SpA) at 3 T (Magnetom VERIO, 8-channel-knee-coil, Siemens Healthcare). As standard of reference, contrast enhanced non fat-saturated coronal and fat-saturated axial T1-w sequences were acquired. These static sequences and the dynamic TWIST–MRA–maximum-intensity-projections (MIP) were separately assessed by two readers in consensus, recording the number of synovial lesions (wrist, intercarpal, metacarpophaleangal/proximal/distal interphalangeal joints), signs of tenosynovitis and vasculitis. Diagnostic confidence was rated (4-point-scale: 4 = excellent; 1 = non-diagnostic). Statistical significance was tested using the Wilcoxon-rank-sum-test. Results: An insignificantly lower number of synovial lesions (n = 72 vs. 89; p = 0.1) and only 3/9 cases with tenosynovitis were identified by the TWIST–MRA. For detected lesions, diagnostic confidence was comparable (MRA: 3.64; static T1-w post contrast: 3.47). In patients with high clinical activity dynamic MRA showed very early synovial enhancement. Only dynamic MRA detected 3 cases of vasculitis (subsequently confirmed with digital-subtraction-angiography). Conclusion: TWIST–MRA facilitates fast detection of synovitis. Although dynamic MRA of the hand is inferior to static contrast enhanced sequences in assessing the number of synovitic and tenosynovitic lesions, its high temporal resolution allows for fast visual grading of disease activity and assessment of vasculitis

  15. 3D non-contrast-enhanced ECG-gated MR angiography of the lower extremities with dual-source radiofrequency transmission at 3.0 T: Intraindividual comparison with contrast-enhanced MR angiography in PAOD patients.

    Science.gov (United States)

    Rasper, Michael; Wildgruber, Moritz; Settles, Marcus; Eckstein, Hans-Henning; Zimmermann, Alexander; Reeps, Christian; Rummeny, Ernst J; Huber, Armin M

    2016-09-01

    To compare prospectively image quality and diagnostic confidence of flow-sensitive 3D turbo spin echo (TSE)-based non-contrast-enhanced MR angiography (NE-MRA) at 3.0 T using dual-source radiofrequency (RF) transmission with contrast-enhanced MRA (CE-MRA) in patients with peripheral arterial occlusive disease (PAOD). After consent was obtained, 35 patients (mean age 69.1 ± 10.6 years) with PAOD stage II-IV underwent NE-MRA followed by CE-MRA. Signal-to-noise ratio and contrast-to-noise ratio were calculated. Subjective image quality was independently assessed by two radiologists and stenosis scoring was performed in 875 arterial segments. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for stenosis classification were calculated using CE-MRA as a reference method. Diagnostic agreement with CE-MRA was evaluated with Cohen's kappa statistics. NE-MRA provided high objective and subjective image quality at all levels of the arterial tree. Sensitivity and specificity for the detection of relevant stenosis was 91 % and 89 %, respectively; the NPV was 96 % and the PPV 78 %. There was good concordance between CE-MRA and NE-MRA in stenosis scoring. 3D electrocardiography (ECG)-gated TSE NE-MRA with patient-adaptive dual-source RF transmission at 3.0 T is a promising alternative for PAOD patients with contraindications for gadolinium-based contrast agents. It offers high sensitivity and NPV values in the detection of clinically relevant arterial stenosis. • Flow-sensitive TSE NE-MRA is a promising technique for PAOD evaluation. • Diagnostic accuracy is comparable to contrast-enhanced MRA. • NE-MRA eliminates the risk of NSF in patients with renal insufficiency. • Costs arising from the use of contrast agents can be avoided.

  16. 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

  17. MR angiography, MR imaging and proton MR spectroscopy in-vivo assessment of skeletal muscle ischemia in diabetic rats.

    Directory of Open Access Journals (Sweden)

    Stefano Delli Pizzi

    Full Text Available To prospectively evaluate the feasibility of using magnetic resonance (MR techniques for in-vivo assessing a rat diabetic model of limb ischemia. Unilateral hind limb ischemia was induced by ligation of the iliac-femoral artery in male streptozotocin-treated and non-diabetic control rats. Four weeks after ligation, rats underwent MR Angiography (MRA, T(1-weighted and Short Time Inversion Recovery (STIR sequences and muscle Proton MR Spectroscopy ((1H-MRS on both hind limbs. After MR examinations, immunoblotting and immunofluorescence analysis were performed. MRA showed a signal void due to flow discontinuation distal to the artery ligation. T(1-weighted and STIR images showed, respectively, the presence of tissue swelling (p = 0.018 for non-diabetic; p = 0.027 for diabetic rats and signal hyperintensity in tissue affected by occlusion. Mean total creatine/water for the occluded limb was significantly lower than for the non-occluded limbs in both non-diabetic (5.46×10(-4 vs 1.14×10(-3, p = 0.028 and diabetic rats (1.37×10(-4 vs 1.10×10(-3; p = 0.018. MR Imaging and (1H-MRS changes were more pronounced in diabetic than in non-diabetic occluded limbs (p = 0.032. MR findings were confirmed by using histological findings. Combined MR techniques can be used to demonstrate the presence of structural and metabolic changes produced by iliac-femoral artery occlusion in rat diabetic model of limb ischemia.

  18. Investigation of the saturation pulse artifact in non-enhanced MR angiography of the lower extremity arteries at 7 Tesla.

    Directory of Open Access Journals (Sweden)

    Sören Johst

    Full Text Available When performing non-enhanced time-of-flight MR angiography of the lower extremity arteries at 7 T with cardiac triggering, the acquisition time is a crucial consideration. Therefore, in previous studies, saturation RF pulses were applied only every second TR. In the axial source images a slight artifact with an appearance similar to aliasing could be observed. The purpose of this study was to investigate the origin of this artifact. The reason for the artifact is supposed to be related to the two effective TRs during acquisition caused by the sparsely applied saturation RF pulse. Several sequence variants were simulated and implemented within the sequence source code to examine this hypothesis. An adaptation of the excitation flip angles for each TR as well as a correction factor for the k-space data was calculated. Additionally, a different ordering of the k-space data during acquisition was implemented as well as the combination of the latter with the k-space correction factor. The observations from the simulations were verified using both a static and a flow phantom and, finally, in a healthy volunteer using the same measurement setup as in previous volunteer and patient studies. Of all implemented techniques, only the reordering of the k-space was capable of suppressing the artifact almost completely at the cost of creating a ringing artifact. The phantom measurements showed the same results as the simulations and could thus confirm the hypothesis regarding the origin of the artifact. This was additionally verified in the healthy volunteer. The origin of the artifact could be confirmed to be the periodic signal variation caused by two effective TRs during acquisition.

  19. Investigation of the saturation pulse artifact in non-enhanced MR angiography of the lower extremity arteries at 7 Tesla.

    Science.gov (United States)

    Johst, Sören; Maderwald, Stefan; Fischer, Anja; Quick, Harald H; Ladd, Mark E; Orzada, Stephan

    2015-01-01

    When performing non-enhanced time-of-flight MR angiography of the lower extremity arteries at 7 T with cardiac triggering, the acquisition time is a crucial consideration. Therefore, in previous studies, saturation RF pulses were applied only every second TR. In the axial source images a slight artifact with an appearance similar to aliasing could be observed. The purpose of this study was to investigate the origin of this artifact. The reason for the artifact is supposed to be related to the two effective TRs during acquisition caused by the sparsely applied saturation RF pulse. Several sequence variants were simulated and implemented within the sequence source code to examine this hypothesis. An adaptation of the excitation flip angles for each TR as well as a correction factor for the k-space data was calculated. Additionally, a different ordering of the k-space data during acquisition was implemented as well as the combination of the latter with the k-space correction factor. The observations from the simulations were verified using both a static and a flow phantom and, finally, in a healthy volunteer using the same measurement setup as in previous volunteer and patient studies. Of all implemented techniques, only the reordering of the k-space was capable of suppressing the artifact almost completely at the cost of creating a ringing artifact. The phantom measurements showed the same results as the simulations and could thus confirm the hypothesis regarding the origin of the artifact. This was additionally verified in the healthy volunteer. The origin of the artifact could be confirmed to be the periodic signal variation caused by two effective TRs during acquisition.

  20. Asymmetry of intracranial internal carotid artery on 3D TOF MR angiography: a sign of unilateral extracranial stenosis

    International Nuclear Information System (INIS)

    Naggara, Olivier; Seiller, Nicolas; Gobin-Metteil, Marie-Pierre; Meder, Jean-Francois; Oppenheim, Catherine; Touze, Emmanuel; Mas, Jean-Louis

    2008-01-01

    The purpose of this case-control study was to determine whether an asymmetry of size of the intracranial internal carotid artery (ICA) on 3D time-of-flight MR angiography (MRA) is predictive of a high-grade cervical ICA stenosis. Ninety-six stroke/TIA consecutive patients were recruited for the study, of whom 32 had unilateral high-grade ICA stenosis (≥70% NASCET) and were included into the case group, and the remaining 64 did not have such high-grade stenosis and were included in the control group. On intracranial MRA, two observers, blinded to the characteristics of cervical ICA stenosis, independently searched for qualitative size asymmetry between ICAs and measured the cross-sectional surface of the intracranial ICAs. An intracranial size asymmetry was seen in 28 of the 32 high-grade stenoses by both readers, and in 10 (reader 1 ) and 8 (reader 2 ) of the 64 controls (sensitivity = 88%, specificity = 84-88%). In patients without agenesia of the A1 segment of the circle of Willis (n = 70), sensitivity was ≥90% and specificity = 96%. Surfaces ratios were significantly different (p < 0.001) between cases and controls. However, using ROC curves analysis, the quantitative processing did not improve the detection when compared with the qualitative assessment of intracranial ICA asymmetry. A size asymmetry of the intracranial ICAs reveals the presence of an underlying high-grade cervical stenosis, with a high degree of confidence, especially in patients without anatomical variant of the anterior part of the circle of Willis. This sign may allow an early detection of high-grade cervical carotid stenosis in stroke patients before dedicated neck imaging is performed. (orig.)

  1. Asymmetry of intracranial internal carotid artery on 3D TOF MR angiography: a sign of unilateral extracranial stenosis

    Energy Technology Data Exchange (ETDEWEB)

    Naggara, Olivier; Seiller, Nicolas; Gobin-Metteil, Marie-Pierre; Meder, Jean-Francois; Oppenheim, Catherine [Faculte de Medecine Rene Descartes, Universite Paris 5. Centre Hospitalier Sainte-Anne, Department of Neuroradiology, Paris cedex 14 (France); Touze, Emmanuel; Mas, Jean-Louis [Faculte de Medecine Rene Descartes, Universite Paris 5. Centre Hospitalier Sainte-Anne, Department of Neurology, Paris cedex 14 (France)

    2008-05-15

    The purpose of this case-control study was to determine whether an asymmetry of size of the intracranial internal carotid artery (ICA) on 3D time-of-flight MR angiography (MRA) is predictive of a high-grade cervical ICA stenosis. Ninety-six stroke/TIA consecutive patients were recruited for the study, of whom 32 had unilateral high-grade ICA stenosis ({>=}70% NASCET) and were included into the case group, and the remaining 64 did not have such high-grade stenosis and were included in the control group. On intracranial MRA, two observers, blinded to the characteristics of cervical ICA stenosis, independently searched for qualitative size asymmetry between ICAs and measured the cross-sectional surface of the intracranial ICAs. An intracranial size asymmetry was seen in 28 of the 32 high-grade stenoses by both readers, and in 10 (reader{sub 1}) and 8 (reader{sub 2}) of the 64 controls (sensitivity = 88%, specificity = 84-88%). In patients without agenesia of the A1 segment of the circle of Willis (n = 70), sensitivity was {>=}90% and specificity = 96%. Surfaces ratios were significantly different (p < 0.001) between cases and controls. However, using ROC curves analysis, the quantitative processing did not improve the detection when compared with the qualitative assessment of intracranial ICA asymmetry. A size asymmetry of the intracranial ICAs reveals the presence of an underlying high-grade cervical stenosis, with a high degree of confidence, especially in patients without anatomical variant of the anterior part of the circle of Willis. This sign may allow an early detection of high-grade cervical carotid stenosis in stroke patients before dedicated neck imaging is performed. (orig.)

  2. 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

  3. 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

  4. 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.

  5. Value of contrast-enhanced 3D MR angiography of the renal arteries

    International Nuclear Information System (INIS)

    Hany, T.F.; Pfammatter, T.; Schmidt, M.; Leung, D.A.; Debatin, J.F.

    1997-01-01

    Purpose: To determine the value of gadolinium-enhanced, three-dimensional breath-hold Magnetic Resonance Angiography (MRA) in the assessment of the aorta and renal arteries in comparison to conventional arteriography (CA). Patients and methods: 49 patients were evaluated with both CA and 3D MRA. 0.3 mmol/kg BW gadolinium-DTPA was administered intravenously in a bolus, using an automated injector. A test bolus method was used for timing of the bolus and beginning of the data acquisition. The intraaterial CA was used as the gold standard. Results: MRA-based assessment of renal artery stenosis was identical with CA in 31 of 45 stenoses (68.8%). Senstivity and specificity for assessment of renal arterial disease by MRA were 84% and 96%; for clinically relevant lesions they amounted to 90% and 98%. Conclusion: The presented contrast-enhanced 3D MRA technique allows for the reliable assessment of renal arterial morphology and pathology. (orig.) [de

  6. 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

  7. Noninvasive follow-up of GDC-treated saccular aneurysms by MR angiography

    International Nuclear Information System (INIS)

    Weber, W.; Henkes, H.; Nahser, H.C.; Roer, N.; Kuehne, D.; Yousry, T.A.; Felber, S.R.

    2001-01-01

    The aim of this study was to determine sensitivity and specificity of magnetic resonance angiography (MRA) for the assessment of durable occlusion of intracranial aneurysms with Guglielmi detachable coils (GDC) and to point out the influence of MRA results in re-intervention strategies. Forty-five patients with 54 aneurysms that were previously treated by endovascular occlusion with GDC were selected for this study. All patients underwent digital subtraction angiography (DSA) and MRA examinations on the same day. The time-of-flight MRA studies were performed on a 1-T scanner. The MRA images were first read by radiologists who were not aware of the DSA results. In a second consensus reading by the neuroradiologists who had performed all interventional procedures of this series, the decision was made as to whether re-treatment was necessary. The distribution of aneurysm sizes, configurations and treatment results were sufficient for an unbiased evaluation. The first blinded evaluation revealed a sensitivity of 71% and a specificity of 95% for MRA assessment of aneurysm reperfusion. In the second consensus reading, the sensitivity increased to 92% and the specificity was 98%. The blinded reading indicates that MRA is a useful adjunct to DSA for the assessment of durable results after endovascular treatment of intracranial aneurysms. In the consensus reading it became obvious that sensitivity and specificity of MRA can be increased to 92 and 98%, respectively, if the results were evaluated by experienced neuroradiologists, including prior knowledge of all other examinations. We have already increased the follow-up intervals for DSA and use MRA intermittently, based on these results. (orig.)

  8. Equilibrium-phase MR angiography: Comparison of unspecific extracellular and protein-binding gadolinium-based contrast media with respect to image quality.

    Science.gov (United States)

    Erb-Eigner, Katharina; Taupitz, Matthias; Asbach, Patrick

    2016-01-01

    The purpose of this study was to compare contrast and image quality of whole-body equilibrium-phase high-spatial-resolution MR angiography using a non-protein-binding unspecific extracellular gadolinium-based contrast medium with that of two contrast media with different protein-binding properties. 45 patients were examined using either 15 mL of gadobutrol (non-protein-binding, n = 15), 32 mL of gadobenate dimeglumine (weakly protein binding, n = 15) or 11 mL gadofosveset trisodium (protein binding, n = 15) followed by equilibrium-phase high-spatial-resolution MR-angiography of four consecutive anatomic regions. The time elapsed between the contrast injection and the beginning of the equilibrium-phase image acquisition in the respective region was measured and was up to 21 min. Signal intensity was measured in two vessels per region and in muscle tissue. Relative contrast (RC) values were calculated. Vessel contrast, artifacts and image quality were rated by two radiologists in consensus on a five-point scale. Compared with gadobutrol, gadofosveset trisodium revealed significantly higher RC values only when acquired later than 15 min after bolus injection. Otherwise, no significant differences between the three contrast media were found regarding vascular contrast and image quality. Equilibrium-phase high-spatial-resolution MR-angiography using a weakly protein-binding or even non-protein-binding contrast medium is equivalent to using a stronger protein-binding contrast medium when image acquisition is within the first 15 min after contrast injection, and allows depiction of the vasculature with high contrast and image quality. The protein-binding contrast medium was superior for imaging only later than 15 min after contrast medium injection. Copyright © 2015 John Wiley & Sons, Ltd.

  9. MR Angiography of Peripheral Arterial Stents: In Vitro Evaluation of 22 Different Stent Types

    Directory of Open Access Journals (Sweden)

    Matthias C. Burg

    2011-01-01

    Full Text Available Purpose. To evaluate stent lumen visibility of a large sample of different peripheral arterial (iliac, renal, carotid stents using magnetic resonance angiography in vitro. Materials and Methods. 21 different stents and one stentgraft (10 nitinol, 7 316L, 2 tantalum, 1 cobalt superalloy, 1 PET + cobalt superalloy, and 1 platinum alloy were examined in a vessel phantom (vessel diameters ranging from 5 to 13 mm filled with a solution of Gd-DTPA. Stents were imaged at 1.5 Tesla using a T1-weighted 3D spoiled gradient-echo sequence. Image analysis was performed measuring three categories: Signal intensity in the stent lumen, lumen visibility of the stented lumen, and homogeneity of the stented lumen. The results were classified using a 3-point scale (good, intermediate, and poor results. Results. 7 stents showed good MR lumen visibility (4x nitinol, 2x tantalum, and 1x cobalt superalloy. 9 stents showed intermediate results (5x nitinol, 2x 316L, 1x PET + cobalt superalloy, and 1x platinum alloy and 6 stents showed poor results (1x nitinol, and 5x 316L. Conclusion. Stent lumen visibility varies depending on the stent material and type. Some products show good lumen visibility which may allow the detection of stenoses inside the lumen, while other products cause artifacts which prevent reliable evaluation of the stent lumen with this technique.

  10. Simultaneous static and cine nonenhanced MR angiography using radial sampling and highly constrained back projection reconstruction.

    Science.gov (United States)

    Koktzoglou, Ioannis; Mistretta, Charles A; Giri, Shivraman; Dunkle, Eugene E; Amin, Parag; Edelman, Robert R

    2014-10-01

    To describe a pulse sequence for simultaneous static and cine nonenhanced magnetic resonance angiography (NEMRA) of the peripheral arteries. The peripheral arteries of 10 volunteers and 6 patients with peripheral arterial disease (PAD) were imaged with the proposed cine NEMRA sequence on a 1.5 Tesla (T) system. The impact of multi-shot imaging and highly constrained back projection (HYPR) reconstruction was examined. The propagation rate of signal along the length of the arterial tree in the cine nonenhanced MR angiograms was quantified. The cine NEMRA sequence simultaneously provided a static MR angiogram showing vascular anatomy as well as a cine display of arterial pulse wave propagation along the entire length of the peripheral arteries. Multi-shot cine NEMRA improved temporal resolution and reduced image artifacts. HYPR reconstruction improved image quality when temporal reconstruction footprints shorter than 100 ms were used (P cine NEMRA was slower in patients with PAD than in volunteers. Simultaneous static and cine NEMRA of the peripheral arteries is feasible. Multi-shot acquisition and HYPR reconstruction can be used to improve arterial conspicuity and temporal resolution. Copyright © 2013 Wiley Periodicals, Inc.

  11. Inversion prepared coronary MR angiography: direct visualization of coronary blood flow

    International Nuclear Information System (INIS)

    Katoh, M.; Spuentrup, E.; Buecker, A.; Guenther, R.W.; Stuber, M.; Manning, W.J.; Botnar, R.M.

    2005-01-01

    Purpose: visualization of coronary blood flow by means of a slice-selective inversion pre-pulse in concert with bright-blood coronary MRA. Materials and methods: coronary magnetic resonance angiography (MRA) of the right coronary artery (RCA) was performed in eight healthy adult subjects on a 1.5 Tesla MR system (Gyroscan ACS-NT, Philips Medical Systems, Best, NL) using a free-breathing navigator-gated and cardiac-triggered 3D steady-state free-precession (SSFP) sequence with radial k-space sampling. Imaging was performed with and without a slice-selective inversion pre-pulse, which was positioned along the main axis of the coronary artery but perpendicular to the imaging volume. Objective image quality parameters such as SNR, CNR, maximal visible vessel length, and vessel border definition were analyzed. Results: in contrast to conventional bright-blood 3D coronary MRA, the selective inversion pre-pulse provided a direct measure of coronary blood flow. In addition, CNR between the RCA and right ventricular blood pool was increased and the vessels had a tendency towards better delineation. Blood SNR and CNR between right coronary blood and epicardial fat were comparable in both sequences. (orig.)

  12. Comparative study of coronary plaque and stenosis: CT versus MR angiography

    International Nuclear Information System (INIS)

    Liu Xin; Zhao Xihai; Cheng Liuquan; Zhao Shaohong; Cai Zulong; Cai Youquan; Yang Li

    2006-01-01

    Objective: To investigate the effect of coronary plaque composition on the extent of stenosis and compare the accuracies of coronary CTA and MRA in detecting significant stenosis (≥50%) caused by different composition plaques. Methods: Thirty patients with coronary heart disease were examined with coronary CTA, MRA and conventional coronary, angiography (CAG) within two weeks. CTA and MRA were performed with a 16-slice CT scanner and hreathhold 3D FIESTA sequence respectively. The coronary plaques were grouped as non-calcified and calcified plaque on CTA images. The accuracies and agreement of CTA and MRA in detecting significant stenosis were evaluated by two experienced radiologists independently using CAG as reference. Results: Fifty-three plaques were detected on CTA. Twenty-eight were non-calcified and the other 25 were calcified. Twenty-one of 28 non-calcified plaques caused significant stenosis on CAG. The sensitivity and specificity of CTA and MRA in detecting significant stenosis were 85.7%, 85.7% and 47.6%, 71.4%, respectively, CTA showed good agreement with CAG (K=0.65). Six of 25 calcified plaques caused significant stenosis on CAG. The sensitivity and specificity of CTA and MRA in detecting significant stenosis were 83.3%, 31.6% and 83.3%, 73.7%, respectively, MRA showed moderate agreement with CAG (K=0.46). Conclusion: CTA was accurate for detecting non-calcified plaque and stenosis, while MRA had advantage to evaluate lumen with severe calcified plaque. (authors)

  13. Contrast enhanced renal MR angiography at 7 Tesla: How much gadolinium do we need?

    Energy Technology Data Exchange (ETDEWEB)

    Beiderwellen, Karsten, E-mail: karsten.beiderwellen@uni-due.de [Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Essen (Germany); Erwin L. Hahn Institute for Magnetic Resonance Imaging, University Duisburg-Essen, Essen (Germany); Kraff, Oliver, E-mail: Oliver.kraff@uni-due.de [Erwin L. Hahn Institute for Magnetic Resonance Imaging, University Duisburg-Essen, Essen (Germany); Laader, Anja, E-mail: anja.laader@uk-essen.de [Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Essen (Germany); Erwin L. Hahn Institute for Magnetic Resonance Imaging, University Duisburg-Essen, Essen (Germany); Maderwald, Stefan, E-mail: Stefan.maderwald@uni-due.de [Erwin L. Hahn Institute for Magnetic Resonance Imaging, University Duisburg-Essen, Essen (Germany); Orzada, Stephan, E-mail: Stephan.orzada@uni-due.de [Erwin L. Hahn Institute for Magnetic Resonance Imaging, University Duisburg-Essen, Essen (Germany); Ladd, Mark E., E-mail: mark.ladd@dkfz-heidelberg.de [Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg (Germany); Forsting, Michael, E-mail: Michael.forsting@uk-essen.de [Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Essen (Germany); Erwin L. Hahn Institute for Magnetic Resonance Imaging, University Duisburg-Essen, Essen (Germany); Lauenstein, Thomas C., E-mail: Thomas.Lauenstein@uni-due.de [Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Essen (Germany); Umutlu, Lale, E-mail: Lale.umutlu@uk-essen.de [Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Essen (Germany); Erwin L. Hahn Institute for Magnetic Resonance Imaging, University Duisburg-Essen, Essen (Germany)

    2017-01-15

    Objectives: To investigate whether a dose reduction of Gadobutrol for renal magnetic resonance angiography (MRA) at 7 Tesla (T) is feasible while preserving diagnostic image quality. Methods: Ten healthy volunteers were enrolled for a renal MRA on a 7 T scanner. Fast low angle shot (FLASH) MRA data sets were obtained utilizing three different doses of Gadobutrol (0.1, 0.05 and 0.025 mmol/kg body weight [BW]). Contrast ratios (CR) were measured in the aorta as well as in the intra- and extraparenchymal arteries compared to the psoas muscle. Qualitative analysis regarding the delineation of vessel structures was performed using a four-point-scale. Results: All doses of Gadobutrol allowed for a good delineation of the aorta and renal arteries. For the extra- and intraparenchymal segmental arteries higher values were observed for full and half dose in comparison to quarter dose. No significant difference was observed for full and half dose. A lower CR was observed for quarter compared to half dose (p < 0.05) for the renal arteries. Conclusions: While best results were observed for half and full dose, a dose reduction to 0.025 mmol/kg BW is justifiable, maintaining a diagnostic image quality. This may be of high interest considering patients with renal impairment.

  14. Analysis of the vertebral venous system in relation to cerebral venous drainage on MR angiography

    International Nuclear Information System (INIS)

    Baik, Seung Kug; Sohn, Chul Ho; Kim, Gab Chul; Kim, Yong Sun

    2004-01-01

    In the supine position, cerebral venous drainage occurs primarily through the internal jugular veins, as seen on venous phase cerebral angiography. However, in the erect position, the vertebral venous system represents the major alternative pathway of cerebral venous drainage, while outflow through the internal jugular veins is absent or negligible. The purpose of this study is to evaluate the vertebral venous system and its relationship between the surrounding venous structures using magnetic resonance angiography (MRA) in the case of subjects in the supine position. We retrospectively reviewed the results of 65 patients (M:F = 31: 34, mean age 61.6 years) who underwent multi-phase contrast-enhanced carotid MRA. The imaging studies were performed using a 3.0 T MR unit (TR: 5.2, TE: 1.1, FA: 20, 3.8 thickness, EC: 1). We analyzed the appearance and extent of the vertebral venous system (vertebral venous plexus and vertebral artery venous plexus) and the internal jugular vein on the venous phase images. We also evaluated the main drainage pattern of the cerebral venous drainage and the drainage pattern of the vertebral venous system. The visualized vertebral venous system was defined as either poor, vertebral venous plexus dominant, vertebral artery venous plexus dominant or mixed. In the vertebral venous system, the vertebral artery venous plexus was visualized in 54 cases (83%). The appearance of the visualized vertebral artery venous plexus was symmetrical in 39 cases (72%) and asymmetrical in 15 cases (28%). The extent of the visualized vertebral artery venous plexus was partial in 26 cases (48%) and complete in 28 cases (52%). The vertebral venous plexus was visualized in 62 cases (95%). The appearance of the visualized vertebral artery venous plexus was symmetrical in 43 cases (69%) and asymmetrical in 19 cases (31%). The extent of the visualized vertebral artery venous plexus was partial in 35 cases (56%) and complete in 27 cases (44%). The appearance of the

  15. Slow clearance gadolinium-based extracellular and intravascular contrast media for three-dimensional MR angiography.

    Science.gov (United States)

    Bremerich, J; Colet, J M; Giovenzana, G B; Aime, S; Scheffler, K; Laurent, S; Bongartz, G; Muller, R N

    2001-04-01

    The objective of this study was to assess two new slow-clearance contrast media with extracellular and intravascular distribution for magnetic resonance angiography (MRA). Extracellular Gd-DTPA-BC(2)glucA and intravascular Gd(DO3A)(3)-lys(16) were developed within the European Biomed2 MACE Program and compared with two reference compounds, intravascular CMD-A2-Gd-DOTA and extracellular GdDOTA, in 12 rats. Pre- and post-contrast three-dimensional MR (TR/TE = 5 msec/2.2 msec; isotropic voxel size 0.86 mm(3)) was acquired for 2 hours. Signal-to-noise enhancement (DeltaSNR) was calculated. Two minutes after injection, all contrast media provided strong vascular signal enhancement. The DeltaSNR for Gd-DTPA-BC(2)glucA, Gd(DO3A)(3)-lys(16), CMD-A2-Gd-DOTA, and GdDOTA were 13.0 +/- 1.8, 25.0 +/- 3.2, 25.0 +/- 4.0, and 18.0 +/- 3.4, respectively. Gd-DTPA-BC(2)glucA, Gd(DO3A)(3)-lys(16), and CMD-A2-Gd-DOTA cleared slowly from the circulation, whereas GdDOTA cleared rapidly. Vascular DeltaSNR at 2 hours were 2.9 +/- 0.6, 25.0 +/- 3.2, 25.0 +/- 4.0, and 0.4 +/- 1.0. Gd(DO3A)(3)-lys(16) provided strong vascular and minor background enhancement, and thus may be useful for MRA or perfusion imaging. Gd-DTPA-BC(2)glucA produces persistent enhancement of extracellular water, and thus may allow quantification of extracellular distribution volume and assessment of myocardial viability.

  16. Two-dimensional time-of-flight MR angiography of mediastinum and pulmonary hilar vessels

    International Nuclear Information System (INIS)

    Honda, Norinari; Machida, Kikuo; Mamiya, Toshio

    1992-01-01

    Two-dimensional time-of-flight magnetic resonance angiography (2D TOF MRA) of mediastinal and pulmonary hilar vessels was performed in 10 patients, seven men and three women with a mean age (range) of 65.7 (48-88) years. The rate of visualization of the vessels and the diagnostic ability of 2D TOF MRA were assessed in comparison with contrast-enhanced CT. A radiofrequency-spoiled gradient echo sequence (SPGR) was used during repeated breath-holding (8-27 seconds) in coronal (8 patients) and axial (2 patients) imaging planes on a 1.5 Tesla superconducting scanner under the following conditions: repetition time/echo time/flip angle/excitation: 25-33/7-8 ms/45deg/1, field-of-view: 30 x 30 cm, slice thickness: 2.5 mm, 32 slices, 256 (frequency) x 192 (phase) matrix, with gradient moment nulling technique. Visualization sufficient to enable diagnosis of the vascular lesion was obtained in 95 (52%) vessels, mere visualization in 63 (35%), and non-visualization in 24 (13%) of the 182 evaluable vessels. The rates of good visualization of pulmonary hilar vessels (26/86, 30%) and veins (26/48, 54%) were significantly lower than that of arteries (43/48, 90%, p<0.05). The sensitivity and specificity of 2D TOF MRA were 77% (10/13) and 100% (83/83), respectively, in 96 evaluable vessels of nine patients. 2D TOF MRA of mediastinum and pulmonary hili is clinically feasible, and may be useful because of its high specificity. (author)

  17. Deep neural network-based computer-assisted detection of cerebral aneurysms in MR angiography.

    Science.gov (United States)

    Nakao, Takahiro; Hanaoka, Shouhei; Nomura, Yukihiro; Sato, Issei; Nemoto, Mitsutaka; Miki, Soichiro; Maeda, Eriko; Yoshikawa, Takeharu; Hayashi, Naoto; Abe, Osamu

    2018-04-01

    The usefulness of computer-assisted detection (CAD) for detecting cerebral aneurysms has been reported; therefore, the improved performance of CAD will help to detect cerebral aneurysms. To develop a CAD system for intracranial aneurysms on unenhanced magnetic resonance angiography (MRA) images based on a deep convolutional neural network (CNN) and a maximum intensity projection (MIP) algorithm, and to demonstrate the usefulness of the system by training and evaluating it using a large dataset. Retrospective study. There were 450 cases with intracranial aneurysms. The diagnoses of brain aneurysms were made on the basis of MRA, which was performed as part of a brain screening program. Noncontrast-enhanced 3D time-of-flight (TOF) MRA on 3T MR scanners. In our CAD, we used a CNN classifier that predicts whether each voxel is inside or outside aneurysms by inputting MIP images generated from a volume of interest (VOI) around the voxel. The CNN was trained in advance using manually inputted labels. We evaluated our method using 450 cases with intracranial aneurysms, 300 of which were used for training, 50 for parameter tuning, and 100 for the final evaluation. Free-response receiver operating characteristic (FROC) analysis. Our CAD system detected 94.2% (98/104) of aneurysms with 2.9 false positives per case (FPs/case). At a sensitivity of 70%, the number of FPs/case was 0.26. We showed that the combination of a CNN and an MIP algorithm is useful for the detection of intracranial aneurysms. 4 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2018;47:948-953. © 2017 International Society for Magnetic Resonance in Medicine.

  18. 'NC100150', a preparation of iron oxide nanoparticles ideal for positive-contrast MR angiography.

    Science.gov (United States)

    Kellar, K E; Fujii, D K; Gunther, W H; Briley-Saebø, K; Spiller, M; Koenig, S H

    1999-08-01

    A laboratory-scale synthesis of NC100150 (iron oxide particles with an oxidized starch coating) was characterized by magnetization measurements (vibrating sample magnetometry, VSM), relaxometry (1/T1 NMRD profiles and 1/T2 at 10 and 20 MHz), and dynamic light scattering (photon correlation spectroscopy, PCS). The results were related to give a self-consistent physical description of the particles: a water-impenetrable part making up 12% of the total particle volume, 82% of this volume consisting of an iron oxide core and the remaining 18% consisting of an oxidized starch rind; and, a water-penetrable part making up 88% of the total particle volume, consisting of oxidized starch polymers and entrained water molecules. Relating the magnetization to the relaxometry results required that the oxidized starch coating slows the diffusivity of solvent water molecules in the vicinity of the iron oxide cores. The effect of the organic coating on water diffusivity, not previously considered in the application of relaxation theory to iron oxide nanoparticles, is supported by the much greater (factor of about 2) diameter obtained from the dynamic light scattering measurements in comparison to that obtained from the magnetization measurements. The present work shows that three physical techniques--VSM, relaxometry, and PCS--are needed for properly assessing iron oxide nanoparticles for use as contrast agents for magnetic resonance angiography (MRA). It is also shown that NC100150 has a narrow range of diameters and the smallest value of r2/r1 reported to date, an asset for MRA.

  19. Ultrafast contrast-enhanced 3D MR angiography of the aorta and renal arteries in apnoea

    International Nuclear Information System (INIS)

    Hany, T.F.; Pfammatter, T.; Schmidt, M.; Leung, D.A.; Debatin, J.F.

    1997-01-01

    Purpose: To determine the value of ultrafast, gadolinium-enhanced, three-dimensional breathhold magnetic resonance angiography (MRA) in the assessment of the aorta and renal arteries in comparison to conventional arteriography (CA). Patients and methods: 49 patients (31 m, 18 f) were evaluated with both CA and 3D MRA. The 3D MRA data set consisted of 44 continuous sections, acquired in apnoea (23-28 s) using the following parameters: T R /T E 3.9/1.5 ms, flip angle 40 , 3/4 k-space acquisition. 0.3 mmol/kg BW gadolinium-DTPA were administered intravenously in a bolus, using an automated injector. A test bolus method was used for timing of the bolus and beginning of the data acquisition. Intraarterial CA was used as the gold standard in 47 patients; in two patients the intraoperative findings were employed as the standard of reference. CA and MRA were interpreted separately by two different radiologists, who were blinded to the results of the other examine. Results: All 11 accessory renal arteries were visualised on MRA. MRA-based assessment of renal artery stenosis was identical with CA in 31 of 41 (75%) stenoses. Sensitivity and specificity values for assessment of renal arterial disease were 84,4% and 96,1%, for haemodynamically significant lesions they amounted to 90% and 98,9%, respectively. Conclusion: The presented ultrafast contrast-enhanced 3D MRA technique allows for the reliable assessment of aortic and renal arterial morphology and pathology. (orig.) [de

  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. 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

  2. MR Angiography (MRA)

    Science.gov (United States)

    ... headsets so that the child can watch a movie while the scan is being performed. Thus, the ... the possible charges you will incur. Web page review process: This Web page is reviewed regularly by ...

  3. Diagnosis of occlusive arterial disease and assessment of IVR with fat-suppressed gadolinium-enhanced three-dimensional MR angiography

    Energy Technology Data Exchange (ETDEWEB)

    Amano, Yasuo; Gemma, Kazuhito; Kawamata, Hiroshi; Okajima, Yuhji; Watari, Jun; Kumazaki, Tatsuo [Nippon Medical School, Tokyo (Japan); Maki, Toshio; Tsuchihashi, Toshio

    1996-10-01

    Fat-suppressed gadolinium-enhanced three-dimensional MR angiography (FS-CE-3D-MRA) was performed to make a diagnosis of occlusive arterial disease and evaluate the effectiveness of IVR treatment for it. FS-CE-3D-MRA delineated stenosis of common iliac arteries, which was confirmed by X-ray angiography. FS-CE-3D-MRA also detected ulcerated plaque and arterial wall irregularity. The effectiveness of IVR as atherectomy and stent placement was accurately assessed with FS-CE-3D-MRA. FS-CE-3D-MRA was useful in evaluating occlusive arterial disease with short examination times and high spatial resolution, although iliac circumflexial arteries were not detected by this technique. (author)

  4. Evaluation of three-dimensional gadolinium-enhanced MR angiography using the timing monitoring function of contrast material (Smart Prep technique)

    International Nuclear Information System (INIS)

    Tsuchihashi, Toshio; Sasaki, Sadayuki; Yoshizawa, Satoshi; Maki, Toshio; Kitagawa, Matsuo; Suzuki, Takeshi

    1998-01-01

    The Smart Prep technique for gadolinium-enhanced three-dimensional MR angiography (3D-MRA) was evaluated in clinical practice. By monitoring signal intensity in the region of interest (tracking volume) in the target vessel, start timing after contrast injection can be optimized using the Smart Prep technique. Successful triggering was obtained in the chest, abdomen, and pelvic areas in about 80% of the cases in this study. Failures with this technique were mainly due to changes in tracking volume caused by patient motion and respiration. We noted that the scan started earlier than expected in the thoracic aorta when part of the heart or pulmonary artery was included in the tracking volume. Thus, care must be taken in defining the size and location of the tracking volume in gadolinium-enhanced 3D-MRA using the Smart Prep technique. (author)

  5. MR angiography of the pelvic and lower leg arteries: starting with time-resolved imaging of the lower leg is recommended

    International Nuclear Information System (INIS)

    Schmitt, R.; Christopoulos, G.; Brunner, S.; Froehner, S.; Dobritz, M.; Fellner, F.

    2001-01-01

    58 patients suffering from peripheral arterial vascular disease were examined using contrast-enhanced MR angiography with the intention of optimizing the visualization of lower leg arteries. Different from the customary acquisition order, were first the arteries of the lower legs depicted with three time-resolved phases. Afterwards, the iliacal and femoral vessels were imaged by applying the floating-table technique in two steps. In all cases, the lower leg arteries were depicted without overlying veins. By injecting the contrast agent in two phases, imaging quality of the iliofemoral arteries was not significantly reduced. - In conclusion, we would recommend the hybrid technique of peripheral contrast-enhanced MRA with primarily starting the acquisition of the lower legs in cases of foot infections or ulcerations where the transit time is reduced bi- or unilaterally. (orig.) [de

  6. Validity of computational hemodynamics in human arteries based on 3D time-of-flight MR angiography and 2D electrocardiogram gated phase contrast images

    Science.gov (United States)

    Yu, Huidan (Whitney); Chen, Xi; Chen, Rou; Wang, Zhiqiang; Lin, Chen; Kralik, Stephen; Zhao, Ye

    2015-11-01

    In this work, we demonstrate the validity of 4-D patient-specific computational hemodynamics (PSCH) based on 3-D time-of-flight (TOF) MR angiography (MRA) and 2-D electrocardiogram (ECG) gated phase contrast (PC) images. The mesoscale lattice Boltzmann method (LBM) is employed to segment morphological arterial geometry from TOF MRA, to extract velocity profiles from ECG PC images, and to simulate fluid dynamics on a unified GPU accelerated computational platform. Two healthy volunteers are recruited to participate in the study. For each volunteer, a 3-D high resolution TOF MRA image and 10 2-D ECG gated PC images are acquired to provide the morphological geometry and the time-varying flow velocity profiles for necessary inputs of the PSCH. Validation results will be presented through comparisons of LBM vs. 4D Flow Software for flow rates and LBM simulation vs. MRA measurement for blood flow velocity maps. Indiana University Health (IUH) Values Fund.

  7. Intraobserver and interobserver variability in CT angiography and MR angiography measurements of the size of cerebral aneurysms

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hye Jeong [Hallym University College of Medicine, Department of Radiology, Kangnam Sacred Heart Hospital, Seoul (Korea, Republic of); Yoon, Dae Young; Lee, Hyung Jin [Hallym University College of Medicine, Department of Radiology, Kangdong Seong-Sim Hospital, Seoul (Korea, Republic of); Kim, Eun Soo [Hallym University College of Medicine, Department of Radiology, Hallym University Sacred Heart Hospital, Anyang, Gyeonggi-do (Korea, Republic of); Jeon, Hong Jun; Lee, Jong Young; Cho, Byung-Moon [Hallym University College of Medicine, Department of Neurosurgery, Kangdong Seong-Sim Hospital, Seoul (Korea, Republic of)

    2017-05-15

    Accurate and reliable measurement of aneurysm size is important for treatment planning. The purpose of this study was to determine intraobserver and interobserver variability of CTA and MRA for measurement of the size of cerebral aneurysms. Thirty patients with 33 unruptured cerebral aneurysms (saccular, >3 mm in their maximal dimension, with no daughter sacs or lobulations) who underwent 256-row multislice CTA, 3-D TOF MRA at 3.0T, and 3D rotational angiography (3DRA) were retrospectively analyzed. Three independent observers measured the neck, height, and width of the aneurysms using the CTA and MRA images. Intraobserver and interobserver variability of CTA and MRA measurements was evaluated using the standardized difference and intraclass correlation coefficient, with 3DRA measurements as the reference standard. In addition, the mean values of the measurements using CTA and MRA were compared with those using 3DRA. The overall intraobserver and interobserver standardized differences in CTA/MRA were 12.83-15.92%/13.48-17.45% and 14.08-17.00%/12.08-17.67%, respectively. The overall intraobserver and interobserver intraclass correlation coefficients of CTA/MRA were 0.88-0.98/0.84-0.96 and 0.86-0.98/0.85-0.95, respectively. Compared to the height and width measurements, measurements of the neck dimensions showed higher intraobserver and interobserver variability. The sizes of the cerebral aneurysms measured by CTA and MRA were 1.13-9.26 and 5.20-9.67% larger than those measured by 3DRA, respectively; however, these differences were not statistically significant. There were no noticeable differences between intraobserver and interobserver variability for both CTA- and MRA-based measurements of the size of cerebral aneurysms. (orig.)

  8. Non-enhanced ECG-gated respiratory-triggered 3-D steady-state free-precession MR angiography with slab-selective inversion: initial experience in visualisation of renal arteries in free-breathing children without renal artery abnormality

    International Nuclear Information System (INIS)

    Klee, Dirk; Lanzman, Rotem Shlomo; Blondin, Dirk; Antoch, Gerald; Schaper, Joerg; Schmitt, Peter; Oh, Jun; Salgin, Burak; Mayatepek, Ertan

    2012-01-01

    ECG-gated non-enhanced balanced steady-state free precession (bSSFP) MR angiography requires neither breath-holding nor administration of contrast material. To investigate the image quality of free-breathing ECG-gated non-enhanced bSSFP MR angiography of renal arteries in children. Fourteen boys and seven girls (mean age, 9.7 years; range, 7 weeks-17 years) with no history of renovascular disease were included. MRI was performed at 1.5 T. Subjective image quality of axial and coronal maximum-intensity-projection reconstructions of four segments (I, aorta and renal artery ostium; II, main renal artery; III, segmental branches; IV, intrarenal vessels) was evaluated using a 4-point scale (4 = excellent, 3 = good, 2 = acceptable, 1 = non-diagnostic). Image quality was excellent for segments I (mean ± SD, 3.9 ± 0.3) and II (4.0 ± 0.1), good for segment III (3.4 ± 0.9) and acceptable for segment IV (2.3 ± 1.1). Mean image quality did not differ between sedated and non-sedated children. bSSFP MR angiography enables visualisation of renal arteries in children. (orig.)

  9. 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

  10. Gadolinium-enhanced MR angiography (Gd-MRA) of thoracic vasculature in an animal model using double-dose gadolinium and quiet breathing

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez, R.J.; Strouse, P.J. [Section of Pediatric Radiology, University of Michigan Health System, Ann Arbor (United States); Londy, F.J. [Dept. of Radiology, University of Michigan Hospitals, Ann Arbor, MI (United States); Wakefield, T.W. [Dept. of Surgery, Section of Vascular Surgery, University of Michigan Hospitals, Ann Arbor, MI (United States)

    2001-08-01

    Objective. To evaluate a gadolinium-enhanced MR angiography (Gd-MRA) imaging protocol for the assessment of thoracic vessels using double-dose gadolinium and quiet breathing. An animal model was used to simulate imaging in infants and young children. Material and methods. Six baboons (Papio anubis), mean weight 5.7 kg, were sedated and intubated. After the injection of double-dose Gd-DTPA (0.2 mmol/kg) through a peripheral vein, a coronal spoiled 3D gradient-echo volume acquisition was obtained during quiet breathing. Two radiologists reviewed the images for visualization of aortic arch, brachiocephalic vessel origins, pulmonary arteries (central, upper lobe and descending branches), and pulmonary veins (upper and lower). Results. Visualization was excellent for the aortic arch, brachiocephalic vessel origins, and pulmonary arteries, including the hilar branches. Visualization was excellent for the lower and right upper pulmonary veins and fair for the left upper pulmonary vein. There was excellent agreement between radiologists. Conclusion. Imaging of thoracic vessels with Gd-MRA using double gadolinium during quiet breathing was effective in our animal model. The advantages of this technique include a short imaging time and depiction of vascular segments - branches of pulmonary arteries and intraparenchymal segments of pulmonary veins - not optimally visualized with other non-invasive imaging techniques. (orig.)

  11. Gadolinium-enhanced MR angiography (Gd-MRA) of thoracic vasculature in an animal model using double-dose gadolinium and quiet breathing

    International Nuclear Information System (INIS)

    Hernandez, R.J.; Strouse, P.J.; Londy, F.J.; Wakefield, T.W.

    2001-01-01

    Objective. To evaluate a gadolinium-enhanced MR angiography (Gd-MRA) imaging protocol for the assessment of thoracic vessels using double-dose gadolinium and quiet breathing. An animal model was used to simulate imaging in infants and young children. Material and methods. Six baboons (Papio anubis), mean weight 5.7 kg, were sedated and intubated. After the injection of double-dose Gd-DTPA (0.2 mmol/kg) through a peripheral vein, a coronal spoiled 3D gradient-echo volume acquisition was obtained during quiet breathing. Two radiologists reviewed the images for visualization of aortic arch, brachiocephalic vessel origins, pulmonary arteries (central, upper lobe and descending branches), and pulmonary veins (upper and lower). Results. Visualization was excellent for the aortic arch, brachiocephalic vessel origins, and pulmonary arteries, including the hilar branches. Visualization was excellent for the lower and right upper pulmonary veins and fair for the left upper pulmonary vein. There was excellent agreement between radiologists. Conclusion. Imaging of thoracic vessels with Gd-MRA using double gadolinium during quiet breathing was effective in our animal model. The advantages of this technique include a short imaging time and depiction of vascular segments - branches of pulmonary arteries and intraparenchymal segments of pulmonary veins - not optimally visualized with other non-invasive imaging techniques. (orig.)

  12. Impact of ECG gating in contrast-enhanced MR angiography for the assessment of the pulmonary veins and the left atrium anatomy

    Energy Technology Data Exchange (ETDEWEB)

    Katoh, M.; Buecker, A.; Muehlenbruch, G.; Guenther, R.W.; Spuentrup, E. [Klinik fuer Radiologische Diagnostik, Universitaetsklinikum RWTH Aachen (Germany); Schauerte, P. [Medizinische Klinik 1, Universitaetsklinikum RWTH Aachen (Germany)

    2006-02-15

    Purpose: Implementation of ECG gating in contrast-enhanced MR angiography (ceMRA) for improved visualization of the pulmonary veins, the left atrium, and the thoracic vessels. Materials and Methods: CeMRA was performed on twelve patients with a history of recurrent atrial fibrillation for the purpose of an intra-individual comparison with and without ECG gating on a 1.5 Tesla MR system (Gyroscan Intera, Philips Medical Systems, Best, NL). Objective image quality parameters such as the signal-to-noise ratio (SNR) of the blood and the contrast-to-noise ratio (CNR) between the blood and myocardium or lung parenchyma were analyzed. The contour sharpness of the pulmonary veins, left atrium, ascending aorta, and pulmonary trunk was also measured. In addition, the artifact level was subjectively assessed by two observers blinded with respect to the sequence parameters. Statistically significant differences (p<0.05) between the procedures were analyzed using the Wilcoxon test and Pearson Chi-square test. Results: The use of ECG gating in ceMRA significantly reduced artifacts caused by cardiac motion and vessel pulsation. This in turn lead to a significant increase in the contour sharpness of the left atrium and the thoracic vessels. In addition, higher SNR and CNR were found using ECG-gated ceMRA compared to standard ceMRA. Conclusion: The use of ECG gating in ceMRA results in artifact-free and sharper delineation of the structures of the heart and thoracic vessels. (orig.)

  13. Impact of ECG gating in contrast-enhanced MR angiography for the assessment of the pulmonary veins and the left atrium anatomy

    International Nuclear Information System (INIS)

    Katoh, M.; Buecker, A.; Muehlenbruch, G.; Guenther, R.W.; Spuentrup, E.; Schauerte, P.

    2006-01-01

    Purpose: Implementation of ECG gating in contrast-enhanced MR angiography (ceMRA) for improved visualization of the pulmonary veins, the left atrium, and the thoracic vessels. Materials and Methods: CeMRA was performed on twelve patients with a history of recurrent atrial fibrillation for the purpose of an intra-individual comparison with and without ECG gating on a 1.5 Tesla MR system (Gyroscan Intera, Philips Medical Systems, Best, NL). Objective image quality parameters such as the signal-to-noise ratio (SNR) of the blood and the contrast-to-noise ratio (CNR) between the blood and myocardium or lung parenchyma were analyzed. The contour sharpness of the pulmonary veins, left atrium, ascending aorta, and pulmonary trunk was also measured. In addition, the artifact level was subjectively assessed by two observers blinded with respect to the sequence parameters. Statistically significant differences (p<0.05) between the procedures were analyzed using the Wilcoxon test and Pearson Chi-square test. Results: The use of ECG gating in ceMRA significantly reduced artifacts caused by cardiac motion and vessel pulsation. This in turn lead to a significant increase in the contour sharpness of the left atrium and the thoracic vessels. In addition, higher SNR and CNR were found using ECG-gated ceMRA compared to standard ceMRA. Conclusion: The use of ECG gating in ceMRA results in artifact-free and sharper delineation of the structures of the heart and thoracic vessels. (orig.)

  14. Follow-up of intracranial aneurysms treated by a WEB flow disrupter: a comparative study of DSA and contrast-enhanced MR angiography.

    Science.gov (United States)

    Mine, Benjamin; Tancredi, Illario; Aljishi, Ali; Alghamdi, Faisal; Beltran, Margarita; Herchuelz, Maxime; Lubicz, Boris

    2016-06-01

    To compare contrast-enhanced MR angiography (CE-MRA) and DSA for the follow-up of intracranial aneurysms (IAs) treated with the Woven EndoBridge embolization system DL (WEB DL; Sequent Medical, Aliso Viejo, California, USA). We retrospectively identified all patients treated with a WEB DL between November 2010 and February 2013 in 2 hospitals. The IA occlusion was graded on follow-up CE-MRA and DSA by 4 independent readers and by 2 readers reaching a consensus, respectively. Interobserver agreement for MRA and intertechnique agreement was evaluated by calculating linear weighted κ. Fifteen patients with 16 IAs were included. Mean delay between MRA and DSA was 2 months (range 0-16 months). Interobserver agreement for MRA was substantial to almost perfect (κ=0.686-0.921; mean κ=0.809). Intertechnique agreement was moderate to substantial (κ=0.579-0.724; mean κ=0.669). Only three out of five inadequately occluded IAs were detected by MRA. CE-MRA is a useful tool for the follow-up of IAs treated with a WEB DL. However, early follow-up with DSA remains mandatory to detect inadequately occluded IAs. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  15. In vitro stent lumen visualisation of various common and newly developed femoral artery stents using MR angiography at 1.5 and 3 tesla.

    Science.gov (United States)

    Syha, R; Ketelsen, D; Kaempf, M; Mangold, S; Sixt, S; Zeller, T; Springer, F; Schick, F; Claussen, C D; Brechtel, K

    2013-02-01

    To evaluate stent lumen assessment of various commonly used and newly developed stents for the superficial femoral artery (SFA) using MR angiography (MRA) at 1.5 and 3 T. Eleven nitinol stents and one cobalt-chromium stent were compared regarding stent lumen visualisation using a common three-dimensional MRA sequence. Maximum visible stent lumen width and contrast ratio were analysed in three representative slices for each stent type. A scoring system for lumen visualisation was applied. Nitinol stents showed significantly better performance than the cobalt chromium stent (P stent lumen ranged between 43.4 and 95.5 %, contrast ratio between 7.2 and 110.6 %. Regarding both field strengths, seven of the nitinol stents were classified as "suitable". Three nitinol stents were "limited", and one nitinol stent and the cobalt chromium stent were "not suitable". Intraluminal loss of signal and artefacts of most of the SFA stents do not markedly limit assessment of stent lumen by MRA at 1.5 and 3 T. MRA can thus be considered a valid technique for detection of relevant in-stent restenosis. Applied field strength does not strongly influence stent lumen assessment in general, but proper choice of field strength might be helpful.

  16. MR angiography of the carotid arteries in 3 D TOF-technique with sagittal ''double-slab'' acquisition using a new head-neck coil

    International Nuclear Information System (INIS)

    Link, J.; Mueller-Huelsbeck, S.; Heller, M.

    1996-01-01

    Purpose: The aim of the study was to assess the value of MR angiography (MRA) in sagittal technique compared to DSA in the evaluation of carotid artery stenosis. Methods: 80 Carotid arteries in 40 symptomatic patients were prospectively studied with DSA and MRA. MRA was carried out by means of 3D time-of-flight technique with a FISP sequence (T E 6 ms/T R 80 ms, flip angle 25 , FOV 240x210 mm, matrix 157x256 mm, in-plane resolution 1.34x0.94 mm, partition thickness 1.32 mm, slab thickness 45 mm, acquisition time 7 min) using a new head-neck coil. Data acquisition was performed in sagittal orientation with the 'double-slab' technique. Imaging quality of the extracranial carotid arteries and correctness of quantification of stenosis was performed. Results: Imaging quality was good at the origin of the carotid arteries in 65%, at the bifurcation region in 98% and near the skull base in 81%. The agreement of DSA and MRA was 96% of the normal arteries (24/25), 90% of the severe stenoses (28/31) and 100% of the occluded arteries (9/9). Conclusion: MRA in sagittal 'double-slab' technique is a noninvasive technique allowing to detect normal arteries and candidates for surgery with high degree of certainity. (orig.) [de

  17. Magnetic resonance imaging in children presenting migraine with aura: Association of hypoperfusion detected by arterial spin labelling and vasospasm on MR angiography findings.

    Science.gov (United States)

    Cadiot, Domitille; Longuet, Romain; Bruneau, Bertrand; Treguier, Catherine; Carsin-Vu, Aline; Corouge, Isabelle; Gomes, Constantin; Proisy, Maïa

    2018-04-01

    Objective A child presenting with a first attack of migraine with aura usually undergoes magnetic resonance imaging (MRI) to rule out stroke. The purpose of this study was to report vascular and brain perfusion findings in children suffering from migraine with aura on time-of-flight MR angiography (TOF-MRA) and MR perfusion imaging using arterial spin labelling (ASL). Methods We retrospectively included all children who had undergone an emergency MRI examination with ASL and TOF-MRA sequences for acute neurological deficit and were given a final diagnosis of migraine with aura. The ASL perfusion maps and TOF-MRA images were independently assessed by reviewers blinded to clinical data. A mean cerebral blood flow (CBF) value was obtained for each cerebral lobe after automatic data post-processing. Results Seventeen children were finally included. Hypoperfusion was identified in one or more cerebral lobes on ASL perfusion maps by visual assessment in 16/17 (94%) children. Vasospasm was noted within the intracranial vasculature on the TOF-MRA images in 12/17 (71%) children. All (100%) of the abnormal TOF-MRA images were associated with homolateral hypoperfusion. Mean CBF values were significantly lower ( P < 0.05) in visually hypoperfused lobes than in normally perfused lobes. Conclusion ASL and TOF-MRA are two totally non-invasive, easy-to-use MRI sequences for children in emergency settings. Hypoperfusion associated with homolateral vasospasm may suggest a diagnosis of migraine with aura.

  18. 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

  19. Patency of runoff detected by MR angiography at 3.0 T with cuff-compression: a predictor of successful endovascular recanalization below the knee

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    Zhu, Yue-Qi; Zhao, Jun-Gong; Wang, Jue; Tan, Hua-Qiao; Lu, Hai-Tao; Cheng, Ying-Sheng; Wei, Li-Ming; Zhang, Pei-Lei [Shanghai Jiao Tong University Affiliated Sixth People' s Hospital, Department of Diagnostic and Interventional Radiology, Shanghai (China); Liu, Fang [Shanghai Jiao Tong University Affiliated Sixth People' s Hospital, Department of Endocrinology, Shanghai (China)

    2014-11-15

    Our aim was to assess the reliability of detecting distal runoff vessels using contrast-enhanced MR angiography (CE-MRA) that were occult on digital subtraction angiography (DSA) for predicting the outcome of endovascular recanalization (ER). This retrospective analysis comprised 63 patients with diabetes (98 limbs) who underwent ER for infrapopliteal lesions. Before ER, they underwent CE-MRA and DSA for peripheral arterial disease; runoff vessels were detected with CE-MRA, but not with DSA. Immediate and follow-up postoperative outcomes were assessed. Univariate analysis was performed to identify variables associated with successful ER. Successful ER was achieved in 85.7 % of limbs, and runoff score was significantly lower than in failure limbs (5.1 ± 1.1 vs. 6.2 ± 1.3; P < 0.05). During follow-up, sustained ankle-brachial index (ABI) improvement was found in 76.6 % claudication patients, and walking distance improvement in 86.5 %; pain was relieved in 70.6 % of critical limb ischemia (CLI) limbs, ulceration healed in 81.3 %, and limb-salvage rate was 100 %. Restenosis/occlusion rate was higher for patients with CLI at 12 months (48.8 % vs. 96.3 % in claudication; P < 0.01). Runoff score was associated with a significantly higher likelihood of ER success (odds ratio = 4.096, 95 % confidence interval: 2.056-8.158; P < 0.001). Runoff vessels detected using CE-MRA could indicate immediate success and better outcome of ER for infrapopliteal occlusions. (orig.)

  20. A general protocol of ultra-high resolution MR angiography to image the cerebro-vasculature in 6 different rats strains at high field.

    Science.gov (United States)

    Pastor, Géraldine; Jiménez-González, María; Plaza-García, Sandra; Beraza, Marta; Padro, Daniel; Ramos-Cabrer, Pedro; Reese, Torsten

    2017-09-01

    Differences in the cerebro-vasculature among strains as well as individual animals might explain variability in animal models and thus, a non-invasive method tailored to image cerebral vessel of interest with high signal to noise ratio is required. Experimentally, we describe a new general protocol of three-dimensional time-of-flight magnetic resonance angiography to visualize non-invasively the cerebral vasculature in 6 different rat strains. Flow compensated angiograms of Sprague Dawley, Wistar Kyoto, Lister Hooded, Long Evans, Fisher 344 and Spontaneous Hypertensive Rat strains were obtained without the use of contrast agents. At 11.7T using a repetition time of 60ms, an isotropic resolution of up to 62μm was achieved; total imaging time was 98min for a 3D data set. The visualization of the cerebral arteries was improved by removing extra-cranial vessels prior to the calculation of maximum intensity projection to obtain the angiograms. Ultimately, we demonstrate that the newly implemented method is also suitable to obtain angiograms following middle cerebral artery occlusion, despite the presence of intense vasogenic edema 24h after reperfusion. The careful selection of the excitation profile and repetition time at a higher static magnetic field allowed an increase in spatial resolution to reliably detect of the hypothalamic artery, the anterior choroidal artery as well as arterial branches of the peri-amygdoidal complex and the optical nerve in six different rat strains. MR angiography without contrast agent can be utilized to study cerebro-vascular abnormalities in various animal models. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  1. Sensitivity encoding (SENSE) for high spatial resolution time-or-flight MR angiography of the intracranial arteries at 3.0 T

    International Nuclear Information System (INIS)

    Willinek, W.A.; Falkenhausen, M. von; Born, M.; Hadizadeh, D.; Manka, C.; Textor, H.J.; Schild, H.H.; Kuhl, C.K.

    2004-01-01

    Methods: In a prospective study TOF MR angiography of the circle of Willis was performed with SENSE in 24 patients on a clinical whole body 3.0 T MR system (Intera, Philips Medical Systems, NL). In the SENSE (S-MRA), a SENSE factor of 2.5 was used to shorten acquisition time and to increase the anatomic coverage (5:12 min.; 150 slices). A matrix of 832x 572 was acquired and reconstructed to 1024 yielding a non-zerofilled voxel size of 0.30x0.44x1.00mm 3 (0.13 mm 3 ). Two readers were asked to review the images regarding the presence of vascular disease, and to rate, in consensus, the quality of the angiograms on a 5-point scale (5 = excellent through 1 = non-diagnostic). Results were compared with the results in 15 subjects who underwent intracranial TOF MRA at 3.0 T without SENSE (NS-MRA: acquisition time, 7:57 min.; 100 slices). Digital subtraction angiography (DSA) served as standard of reference in the 4/24 patients in whom vascular disease was identified. Results: S-MRA at 3.0 T was judged to provide image quality that was adequate for diagnosis or better in 24/24. Median score of image quality of S-MRA and NS-MRA were 5 and 5, respectively. In the 4 patients with DSA correlation, a total of 8 pathologic findings (7 steno-occlusive diseases, 1 aneurysm) were correctly identified on S-MRA. (orig.) [de

  2. 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.

  3. Three-dimensional short-range MR angiography and multiplanar reconstruction images in the evaluation of neurovascular compression in hemifacial spasm

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Woo Suk; Kim, Eui Jong; Lee, Jae Gue; Rhee, Bong Arm [Kyunghee Univ. Hospital, Seoul (Korea, Republic of)

    1998-08-01

    To evaluate the diagnostic efficacy of three-dimensional(3D) short-range MR angiography(MRA) and multiplanar reconstruction(MPR) imaging in hemifacial spasm(HS). Materials and Methods : Two hundreds patients with HS were studied using a 1.5T MRI system with a 3D time-of-flight(TOF) MRA sequence. To reconstruct short-range MRA, 6-10 source images near the 7-8th cranial nerve complex were processed using a maximum-intensity projection technique. In addition, an MPR technique was used to investigate neurovascular compression. We observed the relationship between the root-exit zone(REZ) of the 7th cranial nerve and compressive vessel, and identified the compressive vessels on symptomatic sides. To investigate neurovascular contact, asymptomatic contralateral sides were also evaluated. Results : MRI showed that in 197 of 200 patients there was vascular compression or contact with the facial nerve REZ on symptomatic sides. One of the three remaining patients was suffering from acoustic neurinoma on the symptomatic side, while in two patients there were no definite abnormal findings.Compressive vessels were demonstrated in all 197 patients; 80 cases involved the anterior inferior cerebellar artery(AICA), 74 the posterior cerebellar artery(PICA), 13 the vertebral artery(VA), 16 the VA and AICA, eight the VA and PICA, and six the AICA and PICA. In all 197 patients, compressive vessels were reconstructed on one 3D short-range MRA image without discontinuation from vertebral or basilar arteries. 3D MPR studies provided additional information such as the direction of compression and course of the compressive vessel. In 31 patients there was neurovascular contact on the contralateral side at the 7-8th cranial nerve complex. Conclusion : Inpatients with HS, 3D short-range MRA and MPR images are excellent and very helpful for the investigation of neurovascular compression and the identification of compressive vessels.

  4. Experimental evaluation of contrast-enhanced high-reselution MR angiography in the rabbit. Gd-DTPA versus Gd-DTPA polylysin

    International Nuclear Information System (INIS)

    Vogl, T.J.; Hoffmann, Y.; Juergens, M.; Weinmann, H.J.; Muehler, A.; Yucel, S.; Felix, R.

    1996-01-01

    In ten anesthesized rabbits (average weight 4.3 kg) MR angiography was performed using a 1.5 TMR unit (Magnetom SP63; Siemens Erlangen) and a CP head coil. Arterial MRA (FISP 3D TONE, TR/TE=33/8, Flip 20 ) and venous MRA (FLASH 2D, TR/TE=37/10, Flip 60 ) was performed before and after administration of the paramagnetic contrast agents Gd-DTPA (n=5) or Gd-DTPA polylysine (n=5) at a doseage of 0.1 mmol/kg. In all studies the single selections and the MIP reconstructions were evaluated quantitatively by measuring and calculating signal intensity, percentage enhancement, signal-to-noise and contrast-to-noise ratios. All studies were assessed qualitatively for visualization and distinction of the arterial and venous vessel system by three independent observers before and after the administration of contrast agent. Results: Gd-DTPA-enhanced arterial FISP 3D tone led to a percentage enhancement of 30% for the kidneys, 12% for the superior mesenteric artery, 18% for the deep circumfluent iliac artery, and 7% for the internal iliac artery. In FLASH 2D sequences Gd-DTPA led to a good C/N only for venous abdominal vessels like the left renal vein (2.59) and internal iliac vein (1.66); the percentage enhancement of these structures was between 16 and 21%. Qualitative comparison also showed no significant improvement after injection of Gd-DTPA. In FISP 3D TONE sequences Gd-DTPA polylysine led to a strong percentlage enhancement of right and left kidney (21 and 40%) and deep circumfluent iliac artery (17%). Qualitative evaluation showed improved delineation and contrast of low-diameter vessels, while the soft tissue was only slightly enhanced and did not impair vessel visualization. Conclusion: CMRA using Gd-DTPA and Gd-DTPA polylysine significantly improved the delineation of abdominal vessels, with Gd-DTPA polylysine being superior. (orig.) [de

  5. Evaluation of diabetic peripheral arterial disease in lower limb using 3.0 T contrast-enhanced MR angiography with simultaneous calf compression

    International Nuclear Information System (INIS)

    Li Jie; Zhao Jungong; Zhu Yueqi; Li Minghua; Wang Jue; Qiao Ruihua

    2011-01-01

    Objective: To determine the value of 3.0 T contrast-enhanced MR angiography (CE-MRA) with simultaneous calf compression in demonstrating and diagnosing diabetic peripheral vascular disease. Methods: Sixth-one patients with type 2 diabetes mellitus complicating vascular disease of lower limb were enrolled in this study. The patients included 37 males and 24 females with a mean age of (70±7.65) years. The mean duration of disease was (11.6±6.0) years. The patients were randomly divided into compression group (n=31) and conventional group (n=30). CE-MRA with a 3.0 T MR unit was performed in all patients. During CE-MRA, calf compression with a cuff was simultaneously applied to patients of compression group. DSA, which was regarded as gold standard, was conducted within one week after the procedure. The quality of MRA images was separately evaluated by two radiologists, the results were compared between two groups. Results: Taking DSA findings as reference, the image quality of calf and foot in compression group was much better than that in conventional group (P 50% arterial stenosis or occlusion of leg the image in compression group was also better than that in conventional group (P<0.05). CE-MRA with simultaneous calf compression could significantly eliminate the overlapping venous shadow (P<0.05). Conclusion: The 3.0 T CE-MRA with simultaneous calf compression is a simple and practical technique, it can markedly improve the image quality as well as the diagnostic accuracy of peripheral vascular disease of lower limb in diabetic patients. (authors)

  6. Portosystemic collateral circulation in the falciform ligament: evaluation with three dimensional dynamic contrast enhanced MR angiography in patients with portal hypertension

    International Nuclear Information System (INIS)

    Wu Zhuo; Liang Biling; Li Yong; Zhong Jinglian; Ye Ruixin; Zhang Rong

    2009-01-01

    Objective: The purpose of our study was to investigate three dimensional dynamic contrast enhanced MR angiography(3D DCE MRA) in the detection of portosystemic collateral circulation in the falciform ligament in patients with portal hypertension. Methods: From April 2003 to July 2008, 53 portal hypertension patients with varices in the falciform ligament were evaluated with 3D DCE MRA. Two radiologists independently assessed the number, diameter, location and drainages of the portosystemic collateral circulation in the falciform ligament according to the information on the 3D DCE MRA. Results: The veins in the falciform ligament were classified into the superior and inferior groups, and both groups arise from the left trunk of the portal vein. In our study, the number of varices detected on 3D DCE MRA images varied from 1 to 3, and the diameters of these vessels varied from 0.4 to 2.6 cm. The inferior group consisted of paraumbilical/umbilical veins (47 cases), which flowed toward umbilicus and then drained upwards (n=16) including deep superior epigastric veins (n=7), superficial superior epigastric veins (n=9), downwards (n=40) including deep inferior epigastric veins (n=7), superficial inferior epigastric veins (n=33), or upwards and downwards at the same time (n=9). The superior group of vessels in the falciform ligament were directly anastomosed with the internal thoracic vessels (n=6). Conclusion: In patients with portal hypertension, 3D DCE MRA can optimally demonstrate the portosystemic collateral circulation in the falciform ligament, which includes the superior and inferior drainage groups. (authors)

  7. Preoperative mapping of arterial spinal supply using 3.0-T MR angiography with an intravasal contrast medium and high-spatial-resolution steady-state

    International Nuclear Information System (INIS)

    Mordasini, Pasquale; El-Koussy, Marwan; Schmidli, Jürg; Bonel, Harald Marcel; Ith, Michael; Gralla, Jan; Schroth, Gerhard; Hoppe, Hanno

    2012-01-01

    Introduction: Preoperative mapping of the arterial spinal supply prior to thoracoabdominal aortic aneurysm repair is highly relevant because of high risk for postoperative ischemic spinal cord injuries such as paraparesis or paraplegia. Methods: Twenty-four consecutive patients prior to surgical thoracoabdominal aortic aneurysm repair were investigated. All patients underwent steady-state MR angiography (MRA) of the spinal vasculature with 3-T MRI. The sequence used was a steady-state coronary 3D FLASH with 0.7-mm isotropic voxels. MRA was performed using an intravasal contrast agent. Studies were evaluated by three readers including delineation of arterial spinal supply including both aortic origin and spinal canal entry by three readers. Results: Identification and localization of the Adamkiewicz artery and its spinal canal entry was successful in all patients. Overall depiction of the vascular anatomy was graded as very good in 3 (12.5%), good in 14 (58.4%), sufficient in 5 (20.8%), and poor in 2 (8.3%) patients. Depiction of segmental artery aortic exit level was graded as good in 6 (25.0%), sufficient in 10 (41.7%), poor in 4 (16.7%) and not identifiable in 4 (16.7%) patients. Delineation of segmental artery entry level into the spinal canal was graded as very good in 4 (16.7%), good in 11 (45.8%), sufficient in 6 (25.0%), and poor in 3 (12.5%) patients. Conclusions: The use of 3-T MRA with an intravascular contrast agent and steady-state enables AKA localization including its segmental arteries with regard to the level of aortic origin and spinal canal entry in most patients.

  8. Cardiac MRI in addition to MR angiography: a longitudinal study in vascular risk patients; Kardiale MRT als Ergaenzung zur MR-Angiografie: Eine longitudinale Studie bei vaskulaeren Risikopatienten

    Energy Technology Data Exchange (ETDEWEB)

    Seeger, A.; Grimm, F.; Fenchel, M.; Kramer, U.; Doering, J.S.; Klumpp, B.; Claussen, C.D.; Miller, S. [Abt. fuer Radiologische Diagnostik, Eberhard-Karls-Univ. Tuebingen (Germany); Scheule, A. [Abt. fuer Herz-, Thorax- und Gefaesschirurgie, Eberhard-Karls-Univ. Tuebingen (Germany); May, A.E. [Abt. fuer Kardiologie, Eberhard-Karls-Univ. Tuebingen (Germany)

    2008-05-15

    Purpose: the aim of the study was to assess the feasibility and additional diagnostic information of cardiac MRI as a supplement to state-of-the-art MR angiography (MRA) in the case of vascular risk patients. Therefore, the prevalence of delayed myocardial enhancement (DE) was determined in patients suffering from peripheral artery disease (PAD) and a clinical follow-up was evaluated after 2 years. Materials and method: 87 consecutive patients (ages 66 {+-} 10 years, 67 males) with symptomatic peripheral arterial occlusive disease (n = 68) or abdominal aortic aneurysm (n = 19) were examined using delayed cardiac enhancement (DE) within the clinical indication of MRA at a 1.5T system. A follow-up examination was carried out two years later (24 months {+-} 4 months) with regards to cardiac events (cardiac death, myocardial infarction or acute coronary syndrome, heart insufficiency, coronary revascularization). Results: in total, 40/87 patients had myocardial infarctions shown in MRI (46%). In 25 patients (29%), the myocardial infarction was already known, while in 15 patients (17%) an occult progressing infarction was diagnosed (38% of the myocardial infarcts). Follow-up data was able to be obtained after 2 years for 82 patients. 15 patients had a major cardiac event during the follow-up period, and 10 (67%) of them already showed DE in the MRI. In the group with occult progressing infarctions, cardiac events occurred in 40% (6/15 patients, cardiac death n = 1, ischemia n = 4, heart insufficiency n = 1, bypass n = 1), in patients with known infarction in 17% (4/23 patients, cardiac death n = 1, ischemia n = 3, bypass n = 2) and in 11% of patients without myocardial scars (5/44 patients, cardiac death n = 1, ischemia n = 2, heart insufficiency n = 2). (orig.)

  9. 3D pulmonary perfusion MRI and MR angiography of pulmonary embolism in pigs after a single injection of a blood pool MR contrast agent

    International Nuclear Information System (INIS)

    Fink, Christian; Ley, Sebastian; Puderbach, Michael; Plathow, Christian; Kauczor, Hans-Ulrich; Bock, Michael

    2004-01-01

    The purpose of this study was to assess the feasibility of contrast-enhanced 3D perfusion MRI and MR angiography (MRA) of pulmonary embolism (PE) in pigs using a single injection of the blood pool contrast Gadomer. PE was induced in five domestic pigs by injection of autologous blood thrombi. Contrast-enhanced first-pass 3D perfusion MRI (TE/TR/FA: 1.0 ms/2.2 ms/40 ; voxel size: 1.3 x 2.5 x 4.0 mm 3 ; TA: 1.8 s per data set) and high-resolution 3D MRA (TE/TR/FA: 1.4 ms/3.4 ms/40 ; voxel size: 0.8 x 1.0 x 1.6 mm 3 ) was performed during and after a single injection of 0.1 mmol/kg body weight of Gadomer. Image data were compared to pre-embolism Gd-DTPA-enhanced MRI and post-embolism thin-section multislice CT (n=2). SNR measurements were performed in the pulmonary arteries and lung. One animal died after induction of PE. In all other animals, perfusion MRI and MRA could be acquired after a single injection of Gadomer. At perfusion MRI, PE could be detected by typical wedge-shaped perfusion defects. While the visualization of central PE at MRA correlated well with the CT, peripheral PE were only visualized by CT. Gadomer achieved a higher peak SNR of the lungs compared to Gd-DTPA (21±8 vs. 13±3). Contrast-enhanced 3D perfusion MRI and MRA of PE can be combined using a single injection of the blood pool contrast agent Gadomer. (orig.)

  10. Three-dimensional short-range MR angiography and multiplanar reconstruction images in the evaluation of neurovascular compression in hemifacial spasm

    International Nuclear Information System (INIS)

    Choi, Woo Suk; Kim, Eui Jong; Lee, Jae Gue; Rhee, Bong Arm

    1998-01-01

    To evaluate the diagnostic efficacy of three-dimensional(3D) short-range MR angiography(MRA) and multiplanar reconstruction(MPR) imaging in hemifacial spasm(HS). Materials and Methods : Two hundreds patients with HS were studied using a 1.5T MRI system with a 3D time-of-flight(TOF) MRA sequence. To reconstruct short-range MRA, 6-10 source images near the 7-8th cranial nerve complex were processed using a maximum-intensity projection technique. In addition, an MPR technique was used to investigate neurovascular compression. We observed the relationship between the root-exit zone(REZ) of the 7th cranial nerve and compressive vessel, and identified the compressive vessels on symptomatic sides. To investigate neurovascular contact, asymptomatic contralateral sides were also evaluated. Results : MRI showed that in 197 of 200 patients there was vascular compression or contact with the facial nerve REZ on symptomatic sides. One of the three remaining patients was suffering from acoustic neurinoma on the symptomatic side, while in two patients there were no definite abnormal findings.Compressive vessels were demonstrated in all 197 patients; 80 cases involved the anterior inferior cerebellar artery(AICA), 74 the posterior cerebellar artery(PICA), 13 the vertebral artery(VA), 16 the VA and AICA, eight the VA and PICA, and six the AICA and PICA. In all 197 patients, compressive vessels were reconstructed on one 3D short-range MRA image without discontinuation from vertebral or basilar arteries. 3D MPR studies provided additional information such as the direction of compression and course of the compressive vessel. In 31 patients there was neurovascular contact on the contralateral side at the 7-8th cranial nerve complex. Conclusion : Inpatients with HS, 3D short-range MRA and MPR images are excellent and very helpful for the investigation of neurovascular compression and the identification of compressive vessels

  11. Non-enhanced 3D MR angiography of the lower extremity using ECG-gated TSE imaging with non-selective refocusing pulses. Initial experience

    International Nuclear Information System (INIS)

    Lanzman, R.S.; Blondin, D.; Orzechowski, D.; Scherer, A.; Moedder, U.; Kroepil, P.; Godehardt, E.

    2010-01-01

    Purpose: To evaluate non-enhanced 3D MR angiography using turbo spin echo (TSE) imaging with non-selective refocusing pulses (NATIVE SPACE MRA) for the visualization of the arteries of the lower extremity. Materials and Methods: Three-station imaging (iliac arteries, femoral arteries, arteries of the lower leg) was performed in 8 healthy volunteers and 3 patients with peripheral artery disease (PAD) using a 1.5 T MR scanner. In 8 healthy volunteers, 4 different acquisition schemes were performed with the following imaging parameters: S 1: acquisition with every heartbeat (RR = 1), spoiler gradient of 25 % (SG = 25 %); S 2: RR = 1, SG = 0 %; S 3: RR = 2, SG = 25 %; S 4: RR = 2, SG = 0 %. The subjective image quality on a 4-point-scale (4 = excellent to 1 = not diagnostic) and relative SNR were assessed. In 3 patients with peripheral artery disease (PAD), SPACE MRA was performed for assessment of stenosis. Results: The mean subjective image quality was significantly lower for the iliac arteries compared to the femoral arteries and arteries of the lower leg (p < 0.0001). The subjective image quality for acquisition scheme S 1 was significantly lower than the image quality for S 3 and S 4 for the iliac arteries (p < 0.01), while the subjective image quality for acquisition scheme S 2 was significantly lower than S 3 and S 4 for the femoral arteries and the arteries of the lower leg (p < 0.01). The relative SNR was significantly higher for acquisition schemes S 3 and S 4 as compared to S 1 and S 2 (p < 0.0001) for all regions. SPACE MRA disclosed 7 significant stenoses in 3 PAD patients. Conclusion: ECG-gated SPACE MRA is a promising imaging technique for non-enhanced assessment of the arteries of the lower extremity. (orig.)

  12. Utilizing generalized autocalibrating partial parallel acquisition (GRAPPA) to achieve high-resolution contrast-enhanced MR angiography of hepatic artery: Initial experience in orthotopic liver transplantation candidates

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    Xu Pengju [Department of Radiology, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai (China)]. E-mail: xpjbfc@163.com; Yan Fuhua [Department of Radiology, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai (China)]. E-mail: yanfuhua@yahoo.com; Wang Jianhua [Department of Radiology, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai (China); Lin Jiang [Department of Radiology, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai (China); Fan Jia [Liver Cancer Institute, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai (China)

    2007-03-15

    Objective: To evaluate feasibility of using GRAPPA to acquire high-resolution 3D contrast-enhanced MR angiography (CE-MRA) of hepatic artery and value of GRAPPA for displaying vessels anatomy. Materials and methods: High-resolution CE-MRA using GRAPPA was performed in 67 orthotopic liver transplantation recipient candidates. Signal intensity (SI) and relative SI, i.e., Cv-ro (vessel-to-liver contrast) of the aorta and the hepatic common artery (HCA), were measured. The SI and the relative SI were compared and analyzed using T-test. For purpose of qualitative evaluation, the vessel visualization quality and the order of depicted hepatic artery branches were evaluated by two radiologists independently and assessed by weighted kappa analysis. The depiction of hepatic arterial anatomy and variations was evaluated, and results were correlated with the findings in surgery. Results: The mean SI values were 283.29 {+-} 65.07 (mean {+-} S.D.) for aorta and 283.16 {+-} 64.07 for HCA, respectively. The mean relative SI values were 0.698 {+-} 0.09 for aorta and 0.696 {+-} 0.09 for HCA, respectively. Homogeneous enhancement between aorta and HCA was confirmed by statistically insignificant differences (p-values were 0.89 for mean SI values and 0.12 for mean relative SI values, respectively). The average score for vessel visualization ranged from good to excellent for different artery segments. Overall interobserver agreement in the visualization of different artery segments was excellent (kappa value > 0.80). The distal intrahepatic segmental arteries were well delineated for majority of patients with excellent interobserver agreement. Normal hepatic arterial anatomy was correctly demonstrated in 53 patients, and arterial anomalies were accurately detected on high-resolution MRA image of all 14 patients. Conclusion: High-resolution hepatic artery MRA acquired using GRAPPA in a reproducible manner excellently depicts and delineates small vessels and can be routinely used for

  13. MR-angiography allows defining severity grades of cerebral vasospasm in an experimental double blood injection subarachnoid hemorrhage model in rats.

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    Vesna Malinova

    Full Text Available Magnetic resonance (MR imaging has been used for the detection of cerebral vasospasm (VSP related infarction in experimental subarachnoid hemorrhage (eSAH in rats. Conventional angiography is generally used to visualize VSP, which is an invasive technique with a possible increase in morbidity and mortality. In this study we evaluated the validity of MR-angiography (MRA in detecting VSP and its feasibility to define VSP severity grades after eSAH in rats.SAH was induced using the double-hemorrhage model in 12 rats. In two rats, saline solution was injected instead of blood (sham group. MR was performed on day 1, 2 and on day 5. T1-, T2-, T2*-weighted and time-of-flight MR sequences were applied, which were analyzed by two blinded neuroradiologists. Vessel narrowing of 25-50% was defined as mild, 50-75% as moderate and >75% as severe VSP.We performed a total of 34 MRAs in 14 rats. In 14 rats, MRA was performed on day 2 and day 5. In six rats MRA was additionally performed on day1 before the blood injection. A good visualization of cerebral vessels was possible in all cases. No VSP was seen in the sham group neither on day 2 nor on day 5. We found vasospasm on day 2 in 7 of the 14 rats (50% whereas all 7 rats had mild and one rat had additionally moderate and severe vasospasm in one vessel, respectively. On day 5 we found vasospasm in 8 of the 14 rats (60% whereas 4 rats had severe vasospasm, 1 rat had moderate vasospasm and 3 rats demonstrated mild vasospasm. In 4 of the 14 rats (30% an ischemic lesion was detected on day 5. Three of these rats had severe vasospasm and one rat had mild vasospasm. Severe vasospasm on day 5 was statistically significant correlated with the occurrence of ischemic lesions (Fisher's Exact test, OR 19.5, p = 0.03.MRA is a noninvasive diagnostic tool, which allows a good visualization of the cerebral vasculature and provides reproducible results concerning the detection of VSP and the differentiation into three severity

  14. Aortoiliac stenooculusive disease and aneurysms. Screening with non-contrast enhanced two-dimensional cardiac gated cine phase contrast MR angiography with multiple velocity encoded values and cardiac gated two-dimensional time-of-flight MR angiography

    International Nuclear Information System (INIS)

    Naganawa, Shinji; Koshikawa, Tokiko; Kato, Katsuhiko

    2001-01-01

    To evaluate the performance of two-dimensional cine phase contrast MRA with multi-velocity encoded values (multi-VENC cine PC) and ECG-gated two-dimensional time-of-flight MRA (ECG-2D-TOF) for the detection of stenoocclusive lesions and aneurysms in the aortoiliac area, when each method was used individually and when the two methods were used together. Forty-one patients were included in this study. Multi-VENC cine PC and ECG-2D-TOF were obtained first, then contrast enhanced three-dimensional magnetic resonance angiography (CE-3D-MRA) was performed as the standard of reference. Two observers reviewed the images separately without knowledge of patients' symptoms or histories. Sensitivities and specificities were obtained separately for stenooclusive lesions and aneurysms by two reviewers. When the two methods were applied together, high sensitivities (93.0 by observer 1 and 91.9% by observer 2) and adequate specificities (87.6 and 82.3%) were obtained for stenoocclusive lesions. For aneurysms, moderate to high sensitivities (91.1 and 71.1%) and high specificities (98.8 and 99.4%) were obtained. These results suggest that the performance of two non-contrast enhanced MRA techniques may be valuable as a screening tool when the two methods are applied together. (author)

  15. Gadofosveset-enhanced MR angiography of the pedal arteries in patients with diabetes mellitus and comparison with selective intraarterial DSA

    International Nuclear Information System (INIS)

    Roehrl, Boris; Kunz, Rainer Peter; Oberholzer, Katja; Pitton, Michael Bernhard; Dueber, Christoph; Kreitner, Karl-Friedrich; Neufang, Achim

    2009-01-01

    To compare gadofosveset-enhanced magnetic resonance angiography (MRA) of the pedal vasculature with selective intraarterial DSA. Eighteen patients with PAOD and type II diabetes were prospectively examined at 1.5 T. For contrast enhancement, 0.03 mmol/kg body weight gadofosveset was used. MR imaging consisted of dynamic and of high-resolution steady-state imaging. Selective digital subtraction angiography (DSA) was performed within 5 days and served as standard of reference. Image analysis was done by two observers. There were no differences between MRA and DSA regarding overall image quality. First-pass MRA detected significantly more patent vessel segments than did DSA (P < 0.001, kappa = 0.46). Interobserver agreement of MRA was very good with respect to the detection of patent vessel segments and the assessment of hemodynamically relevant stenoses (kappa = 0.97 and 0.89, respectively). Steady-state imaging depicted significantly more patent metatarsal arteries than did dynamic imaging, and delineated inflammatory complications including osteomyelitis, soft-tissue abscesses, and fistulas related to the diabetic foot. Gadofosveset-enhanced MRA of the pedal vasculature proved to be superior to DSA. It offered a long imaging time window, and allowed for better depiction of the pedal outflow. Steady-state imaging delineated inflammatory complications associated with the diabetic foot. (orig.)

  16. Gadofosveset-enhanced MR angiography of the pedal arteries in patients with diabetes mellitus and comparison with selective intraarterial DSA

    Energy Technology Data Exchange (ETDEWEB)

    Roehrl, Boris; Kunz, Rainer Peter; Oberholzer, Katja; Pitton, Michael Bernhard; Dueber, Christoph; Kreitner, Karl-Friedrich [Johannes Gutenberg University Mainz, Department of Diagnostic and Interventional Radiology, Mainz (Germany); Neufang, Achim [Johannes Gutenberg University Mainz, Department of Cardiothoracic and Vascular Surgery, Mainz (Germany)

    2009-12-15

    To compare gadofosveset-enhanced magnetic resonance angiography (MRA) of the pedal vasculature with selective intraarterial DSA. Eighteen patients with PAOD and type II diabetes were prospectively examined at 1.5 T. For contrast enhancement, 0.03 mmol/kg body weight gadofosveset was used. MR imaging consisted of dynamic and of high-resolution steady-state imaging. Selective digital subtraction angiography (DSA) was performed within 5 days and served as standard of reference. Image analysis was done by two observers. There were no differences between MRA and DSA regarding overall image quality. First-pass MRA detected significantly more patent vessel segments than did DSA (P < 0.001, kappa = 0.46). Interobserver agreement of MRA was very good with respect to the detection of patent vessel segments and the assessment of hemodynamically relevant stenoses (kappa = 0.97 and 0.89, respectively). Steady-state imaging depicted significantly more patent metatarsal arteries than did dynamic imaging, and delineated inflammatory complications including osteomyelitis, soft-tissue abscesses, and fistulas related to the diabetic foot. Gadofosveset-enhanced MRA of the pedal vasculature proved to be superior to DSA. It offered a long imaging time window, and allowed for better depiction of the pedal outflow. Steady-state imaging delineated inflammatory complications associated with the diabetic foot. (orig.)

  17. Evaluation of the supraaortic arteries using non-contrast-enhanced Velocity MR Angiography ''Inhance''

    Energy Technology Data Exchange (ETDEWEB)

    Lummel, Nina; Lutz, Juergen; Linn, Jennifer [University of Munich (LMU), Department of Neuroradiology, Munich (Germany); Boeckh-Behrens, Tobias [Technical University Munich, Department of Neuroradiology, Munich (Germany); Burke, Michael [GE Healthcare, Solingen (Germany)

    2012-11-15

    The aim of this study was to compare the recently developed phase contrast-based Inhance 3D Velocity magnetic resonance angiography technique (Inhance) to the contrast-enhanced standard method (CE-MRA) in the evaluation of the supraaortic arteries. Inhance and CE-MRA were performed in ten consecutive patients with a suspected pathology of the supraaortic arteries on a 3-T MR scanner. Two neuroradiologists evaluated in consensus both sequences regarding the visualisation of the supraaortic arteries and their segments on a five-point score. Diagnostic certainty regarding the overall presence of a vascular pathology was rated on the same five-point score. On CE-MRA as well as on Inhance, a vascular pathology of the supraaortic arteries was detected in seven patients. There was no statistically significant difference in the overall diagnostic certainty regarding the presence or absence of pathologic findings for CE-MRA compared to Inhance. Furthermore, no statistically significant difference was found with regard to visualisation of the distal cervical and intracranial arterial segments, while CE-MRA was superior to Inhance in the visualisation of the origins of the cervical vessels from the aortic arch. Non-contrast Inhance proved useful in the evaluation of the supraaortic arteries with limited assessment of the proximal supraaortic branches. Hence, this technique features a valuable alternative to CE-MRA in the visualisation of the supraaortic arteries, particularly in patients with renal insufficiency. (orig.)

  18. The usefulness and the limitation of MR angiography for the evaluation of colateral veins in portal hypertension

    International Nuclear Information System (INIS)

    Komazaki, Toshio

    1994-01-01

    The usefulness and the limitation of magnetic resonance angiography (MRA) for the assessment of the portal vein and its branches, i.e., the collateral veins of portal hypertensive patients, were studied. In a total of 22 patients with portal hypertension, both MRA and percutaneous transhepatic portography (PTP) were done at the same time. MRA and PTP images were read at random by three observers. The discriminative scores, decided from the grades of clearness of images, were calculated for six portal venous vessels. The discrimination of the portal vein, splenic vein, paraumbilical vein and gastrorenal shunt was easy on condition that they were clearly visualized by PTP. Thus the accuracy of MRA, which was calculated by comparing it with PTP, the gold standard, was high and above 95%. Regarding the left gastric vein and short gastric vein, the accuracy of MRA were lower than the former four vessels but were still above 80%. MRA, the noninvasive method, seems useful for the first choice to see the total image of portal venous system. (author)

  19. Contrast-enhanced three-dimensional MR angiography of neck vessels: does dephasing effect alter diagnostic accuracy?

    International Nuclear Information System (INIS)

    Cosottini, M.; Calabrese, R.; Murri, L.; Puglioli, M.; Zampa, V.; Michelassi, M.C.; Ortori, S.; Bartolozzi, C.

    2003-01-01

    The aim of this study was to evaluate diagnostic accuracy of contrast-enhanced MRA (CEMRA) compared with digital subtraction angiography (DSA) in studying neck vessels of 48 patients. In three groups of patients, we used three MRA protocols differing for voxel size to assess if intravoxel dephasing effects could modify accuracy of CEMRA. Accuracy and correlation with DSA results were calculated in all patients and separately in the three groups. A qualitative analysis of the likeness between morphology of the stenosis in CEMRA and DSA images was also assessed. In all patients accuracy and agreement with DSA were 96% and k=0.85 in subclavian arteries, 96% and k=0.84 in vertebral artery, 97% and k=0.88 in common carotid arteries, and 94% and k=0.86 in internal carotid arteries. In the three groups accuracy and agreement with DSA did not show any significant difference. Qualitative analysis of CEMRA and DSA images revealed a better agreement in depicting the morphology of stenosis using a smaller voxel size. The CEMRA represents a powerful tool for the non-invasive evaluation of neck vessels. Overestimation trend of CEMRA is confirmed and the reduction of voxel size, decreasing the dephasing intravoxel effect, allows to have a better overlapping of stenosis morphology on CEMRA compared with DSA, but it does not yield diagnostic gain in the stenosis grading. (orig.)

  20. Reflux venous flow in dural sinus and internal jugular vein on 3D time-of-flight MR angiography

    International Nuclear Information System (INIS)

    Jang, Jinhee; Kim, Bum-soo; Kim, Bom-yi; Choi, Hyun Seok; Jung, So-Lyung; Ahn, Kook-Jin; Byun, Jae Young

    2013-01-01

    Reflux venous signal on the brain and neck time-of-flight magnetic resonance angiography (TOF MRA) is thought to be related to a compressed left brachiocephalic vein. This study is aimed to assess the prevalence of venous reflux flow in internal jugular vein (IJV), sigmoid sinus/transverse sinus (SS/TS), and inferior petrosal sinus (IPS) on the brain and neck TOF MRA and its pattern. From the radiology database, 3,475 patients (1,526 men, 1,949 women, age range 19-94, median age 62 years) with brain and neck standard 3D TOF MRA at 3 T and 1.5 T were identified. Rotational maximal intensity projection images of 3D TOF MRA were assessed for the presence of reflux flow in IJV, IPS, and SS/TS. Fifty-five patients (1.6 %) had reflux flow, all in the left side. It was more prevalent in females (n = 43/1,949, 2.2 %) than in males (n = 12/1,526, 0.8 %) (p = 0.001). The mean age of patients with reflux flow (66 years old) was older than those (60 years old) without reflux flow (p = 0.001). Three patients had arteriovenous shunt in the left arm for hemodialysis. Of the remaining 52 patients, reflux was seen on IJV in 35 patients (67.3 %). There were more patients with reflux flow seen on SS/TS (n = 34) than on IPS (n = 25). Venous reflux flow on TOF MRA is infrequently observed, and reflux pattern is variable. Because it is exclusively located in the left side, the reflux signal on TOF MRA could be an alarm for an undesirable candidate for a contrast injection on the left side for contrast-enhanced imaging study. (orig.)

  1. Fusion of CT Angiography or MR Angiography with Unenhanced CBCT and Fluoroscopy Guidance in Endovascular Treatments of Aorto-Iliac Steno-Occlusion: Technical Note on a Preliminary Experience

    Energy Technology Data Exchange (ETDEWEB)

    Ierardi, Anna Maria; Duka, Ejona [University of Insubria, Interventional Radiology, Department of Radiology (Italy); Radaelli, Alessandro [Philips Healthcare (Netherlands); Rivolta, Nicola; Piffaretti, Gabriele [University of Insubria, Vascular Surgery Department (Italy); Carrafiello, Gianpaolo, E-mail: gcarraf@gmail.com [University of Insubria, Interventional Radiology, Department of Radiology (Italy)

    2016-01-15

    AimTo evaluate the feasibility of image fusion (IF) of pre-procedural arterial-phase CT angiography or MR angiography with intra-procedural fluoroscopy for road-mapping in endovascular treatment of aorto-iliac steno-occlusive disease.Materials and MethodsBetween September and November, 2014, we prospectively evaluated 5 patients with chronic aorto-iliac steno-occlusive disease, who underwent endovascular treatment in the angiography suite. Fusion image road-mapping was performed using angiographic phase CT images or MR images acquired before and intra-procedural unenhanced cone-beam CT. Radiation dose of the procedure, volume of intra-procedural iodinated contrast medium, fluoroscopy time, and overall procedural time were recorded. Reasons for potential fusion imaging inaccuracies were also evaluated.ResultsImage co-registration and fusion guidance were feasible in all procedures. Mean radiation dose of the procedure was 60.21 Gycm2 (range 55.02–63.75 Gycm2). The mean total procedure time was 32.2 min (range 27–38 min). The mean fluoroscopy time was 12 min and 3 s. The mean procedural iodinated contrast material dose was 24 mL (range 20–40 mL).ConclusionsIF gives Interventional Radiologists the opportunity to use new technologies in order to improve outcomes with a significant reduction of contrast media administration.

  2. Fusion of CT Angiography or MR Angiography with Unenhanced CBCT and Fluoroscopy Guidance in Endovascular Treatments of Aorto-Iliac Steno-Occlusion: Technical Note on a Preliminary Experience

    International Nuclear Information System (INIS)

    Ierardi, Anna Maria; Duka, Ejona; Radaelli, Alessandro; Rivolta, Nicola; Piffaretti, Gabriele; Carrafiello, Gianpaolo

    2016-01-01

    AimTo evaluate the feasibility of image fusion (IF) of pre-procedural arterial-phase CT angiography or MR angiography with intra-procedural fluoroscopy for road-mapping in endovascular treatment of aorto-iliac steno-occlusive disease.Materials and MethodsBetween September and November, 2014, we prospectively evaluated 5 patients with chronic aorto-iliac steno-occlusive disease, who underwent endovascular treatment in the angiography suite. Fusion image road-mapping was performed using angiographic phase CT images or MR images acquired before and intra-procedural unenhanced cone-beam CT. Radiation dose of the procedure, volume of intra-procedural iodinated contrast medium, fluoroscopy time, and overall procedural time were recorded. Reasons for potential fusion imaging inaccuracies were also evaluated.ResultsImage co-registration and fusion guidance were feasible in all procedures. Mean radiation dose of the procedure was 60.21 Gycm2 (range 55.02–63.75 Gycm2). The mean total procedure time was 32.2 min (range 27–38 min). The mean fluoroscopy time was 12 min and 3 s. The mean procedural iodinated contrast material dose was 24 mL (range 20–40 mL).ConclusionsIF gives Interventional Radiologists the opportunity to use new technologies in order to improve outcomes with a significant reduction of contrast media administration

  3. MR angiography of stenosis and aneurysm models in the pulsatile flow: variation with imaging parameters and concentration of contrast media

    International Nuclear Information System (INIS)

    Park, Kyung Joo; Park, Jae Hyung; Lee, Hak Jong; Won, Hyung Jin; Lee, Dong Hyuk; Min, Byung Goo; Chang, Kee Hyun

    1997-01-01

    The image quality of magnetic resonance angiography (MRA) varies according to the imaging techniques applied and the parameters affected by blood flow patterns, as well as by the shape of the blood vessels. This study was designed to assess the influence on signal intensity and its distribution of the geometry of these vessels, the imaging parameters, and the concentration of contrast media in MRA of stenosis and aneurysm models. MRA was performed in stenosis and aneurysm models made of glass tubes, using pulsatile flow with viscosity and flow profile similar to those of blood. Slice and maximum intensity projection (MIP) images were obtained using various imaging techniques and parameters;there was variation in repetition time, flip angle, imaging planes, and concentrations of contrast media. On slice images of three-dimensional (3D) time-of-flight (TOF) techniques, flow signal intensity was measured at five locations in the models, and contrast ratio was calculated as the difference between flow signal intensity (SI) and background signal intensity (SIb) divided by background signal intensity or (SI-SIb)/SIb. MIP images obtained by various techniques and using various parameters were also analyzed, with emphasis in the stenosis model on demonstrated degree of stenosis, severity of signal void and image distortion, and in the aneurysm model, on degree of visualization, distortion of contour and distribution of signals. In 3D TOF, the shortest TR (36 msec) and the largest FA (50 deg ) resulted in the highest contrast ratio, but larger flip angles did not effectively demonstrate the demonstration of the peripheral part of the aneurysm. Loss of signal was most prominent in images of the stenosis model obtained with parallel or oblique planes to the flow direction. The two-dimensional TOF technique also caused signal void in stenosis, but precisely demonstrated the aneurysm, with dense opacification of the peripheral part. The phase contrast technique showed some

  4. Advantages of T2 reversed fast spin-echo image and enhanced three-dimensional surface MR angiography for the diagnosis of cerebral arteriovenous malformations

    International Nuclear Information System (INIS)

    Tanabe, Sumiyoshi; Honmou, Osamu; Minamida, Yoshihiro; Hashi, Kazuo

    2001-01-01

    Although the anatomical investigation of cerebral arteriovenous malformation (AVM) with conventional neuro-imagings considerably supports the preoperative evaluation, it is still hard to dissect the detailed anatomical conformations of AVMs such as location of nidus, identification of feeding arteries or draining veins, and the three-dimensional configuration of nidus in sulci or gyri. In this study, we investigated the efficacy of enhanced three-dimensional surface MR angiography (surface MRA) and T2 reversed image (T2R image) in the diagnosis and surgical planning for cerebral AVMs. The diagnostic accuracy was studied in twelve AVMs: four AVMs closed to motor area, one to Broca area, one to Wernicke area, four in temporal lobe, and two in occipital lobe. Images were obtained with a SIGNA HORIZON LX 1.5T VER 8.2. To construct T2R, the brain is scanned by fast SE method with long TR and was displayed with the reversed gray scale, which seemed similar to T1WI. Surface MRA is a fusion image of MRA and surface image in the workstation. The original data was obtained by enhanced 3D-SPGR method. MRA image was reconstructed with MIP method, and surface image was manipulated with a volume rendering method. T2R images demonstrated seven sulcal AVMs, three gyral AVMs, and two sulco-gyral AVMs; five AVMs located on cortex, four extended to subcortex, and three to paraventricular brain. The images clearly showed six AVMs had hypervascular network such as modja-modja vascular formation. Surface MRA represented nidus adjacent to eloquent area. They were present in central sulcus, precentral sulcus, intraparietal sulcus, inferior frontal sulcus, sylvian fissure, superior temporal sulcus, inferior temporal sulcus, superior temporal gyrus, inferior temporal gyrus, medial temporal gyrus, premotor area and superior frontal sulcus, precuneus and parieto-occipital sulcus. It was easy to identify the point of feeding arteries going down into the sulcus and the junction-point of nidus

  5. Advantages of T2 reversed fast spin-echo image and enhanced three-dimensional surface MR angiography for the diagnosis of cerebral arteriovenous malformations

    Energy Technology Data Exchange (ETDEWEB)

    Tanabe, Sumiyoshi; Honmou, Osamu; Minamida, Yoshihiro; Hashi, Kazuo [Sapporo Medical Univ. (Japan). School of Medicine

    2001-09-01

    Although the anatomical investigation of cerebral arteriovenous malformation (AVM) with conventional neuro-imagings considerably supports the preoperative evaluation, it is still hard to dissect the detailed anatomical conformations of AVMs such as location of nidus, identification of feeding arteries or draining veins, and the three-dimensional configuration of nidus in sulci or gyri. In this study, we investigated the efficacy of enhanced three-dimensional surface MR angiography (surface MRA) and T2 reversed image (T2R image) in the diagnosis and surgical planning for cerebral AVMs. The diagnostic accuracy was studied in twelve AVMs: four AVMs closed to motor area, one to Broca area, one to Wernicke area, four in temporal lobe, and two in occipital lobe. Images were obtained with a SIGNA HORIZON LX 1.5T VER 8.2. To construct T2R, the brain is scanned by fast SE method with long TR and was displayed with the reversed gray scale, which seemed similar to T1WI. Surface MRA is a fusion image of MRA and surface image in the workstation. The original data was obtained by enhanced 3D-SPGR method. MRA image was reconstructed with MIP method, and surface image was manipulated with a volume rendering method. T2R images demonstrated seven sulcal AVMs, three gyral AVMs, and two sulco-gyral AVMs; five AVMs located on cortex, four extended to subcortex, and three to paraventricular brain. The images clearly showed six AVMs had hypervascular network such as modja-modja vascular formation. Surface MRA represented nidus adjacent to eloquent area. They were present in central sulcus, precentral sulcus, intraparietal sulcus, inferior frontal sulcus, sylvian fissure, superior temporal sulcus, inferior temporal sulcus, superior temporal gyrus, inferior temporal gyrus, medial temporal gyrus, premotor area and superior frontal sulcus, precuneus and parieto-occipital sulcus. It was easy to identify the point of feeding arteries going down into the sulcus and the junction-point of nidus

  6. Utilizing generalized autocalibrating partial parallel acquisition (GRAPPA) to achieve high-resolution contrast-enhanced MR angiography of hepatic artery: Initial experience in orthotopic liver transplantation candidates

    International Nuclear Information System (INIS)

    Xu Pengju; Yan Fuhua; Wang Jianhua; Lin Jiang; Fan Jia

    2007-01-01

    Objective: To evaluate feasibility of using GRAPPA to acquire high-resolution 3D contrast-enhanced MR angiography (CE-MRA) of hepatic artery and value of GRAPPA for displaying vessels anatomy. Materials and methods: High-resolution CE-MRA using GRAPPA was performed in 67 orthotopic liver transplantation recipient candidates. Signal intensity (SI) and relative SI, i.e., Cv-ro (vessel-to-liver contrast) of the aorta and the hepatic common artery (HCA), were measured. The SI and the relative SI were compared and analyzed using T-test. For purpose of qualitative evaluation, the vessel visualization quality and the order of depicted hepatic artery branches were evaluated by two radiologists independently and assessed by weighted kappa analysis. The depiction of hepatic arterial anatomy and variations was evaluated, and results were correlated with the findings in surgery. Results: The mean SI values were 283.29 ± 65.07 (mean ± S.D.) for aorta and 283.16 ± 64.07 for HCA, respectively. The mean relative SI values were 0.698 ± 0.09 for aorta and 0.696 ± 0.09 for HCA, respectively. Homogeneous enhancement between aorta and HCA was confirmed by statistically insignificant differences (p-values were 0.89 for mean SI values and 0.12 for mean relative SI values, respectively). The average score for vessel visualization ranged from good to excellent for different artery segments. Overall interobserver agreement in the visualization of different artery segments was excellent (kappa value > 0.80). The distal intrahepatic segmental arteries were well delineated for majority of patients with excellent interobserver agreement. Normal hepatic arterial anatomy was correctly demonstrated in 53 patients, and arterial anomalies were accurately detected on high-resolution MRA image of all 14 patients. Conclusion: High-resolution hepatic artery MRA acquired using GRAPPA in a reproducible manner excellently depicts and delineates small vessels and can be routinely used for evaluating

  7. Assessment of renal artery stenosis of transplanted kidney by time resolved gadolinium-enhanced three-dimensional MR angiography. Preliminary phantom study and clinical evaluation

    International Nuclear Information System (INIS)

    Hayano, Toshio

    2001-01-01

    The purpose of this study was to determine a suitable imaging parameters of time-resolved Gd-enhanced three-dimensional MR angiography (TRE3DMRA) for the evaluation of renal artery stenosis of transplanted kidneys and to investigate the usefulness of TRE3DMRA in 166 clinical cases. Source images were obtained 3dFLASH with zero-filling interpolation (turbo MRA) using Siemens Magneton 1.5T. Acrylate tubes with 6 mm inner diameter filled with diluted Gd-DTPA were used as special phantoms. In the tubes, 25%, 50%, and 75% stenosis were made for simulating arterial stenosis, respectively. According to our clinical experiences, we decided 10 seconds or less acquisition time to obtaining renal artery images without overlapping with renal veins. To determine slice thickness, the degrees of stenosis of the phantom images obtained 8-second acquisition time in variable slice thickness were independently interpreted with visual inspection by two experienced diagnostic radiologists. One hundred sixty-six patients underwent renal transplantation were evaluated clinically. Using a power injector, 0.1 mmol/kg Gd-DTPA was injected after the test scan with 1 ml Gd-DTPA for the determination of acquisition timing. MR images were obtained in the following imaging parameters; 4-mm slice thickness and 8-second acquisition time based on the results of phantom studies. Source images were noted in oblique coronal direction encompassing the entire renal arteries from iliac arteries to renal hili. Based on phantom study, slice thickness must be less than 4-mm to demonstrate the significant stenotic portion (>50%) of the phantom simulating transplanted renal artery. In 150 of 166 patients, excellent images of renal arteries were obtained without overlapping with renal veins. Causes of poor images were mainly inadequate timing of image acquisition. We can decide the imaging parameters of TRE3DMRA for the evaluation of renal artery stenosis of transplanted kidneys. Using these parameters, in 150

  8. Turbulence-resistant MR angiography

    International Nuclear Information System (INIS)

    Wolf, R.L.; Brown, D.G.; La Plante, C.C.; Riederer, S.J.; Ehman, R.L.

    1990-01-01

    Current MR angiographic techniques have difficulties in depicting some vascular features due to disordered flow patterns. The signal loss causing these difficulties is commonly attributed to intravoxel phase dispersion. In this paper, the authors test the hypothesis that signal loss is also due to view-to-view changes in the modulus and phase of magnetization in vascular volume elements. A two-dimensional Fourier transform, gradient-echo sequence was modified to apply a constant phase encoding in each repetition. signal from view-to-view variations in modulus or phase of magnetization of vascular volume elements is thus distinct from signal arising from static or constant motion elements and can be enhanced with application of a clipped adaptive histogram equalization filter. Angiographic projection images were created by integrating along pixels in each image, orthogonal to the readout axis

  9. Interventional and intravascular MR angiography

    International Nuclear Information System (INIS)

    Ladd, M.E.; Debatin, J.F.

    2000-01-01

    Magnetic resonance imaging (MRI) has a number of characteristics which make it attractive for guidance of intravascular therapeutic procedures, including high soft tissue contrast, imaging in any arbitrary oblique plane, lack of ionizing radiation, and the ability to provide functional information, such as flow velocity and volume per unit time. For MR guidance of vascular interventions to be safe, catheters and guidewires must be visualized relative to the vascular system and surrounding tissues. A number of approaches for making instruments visible in an MR environment are presented, including both passive and active techniques. Passive techniques depend on contrast agents or susceptibility artifacts, whereas active techniques, including MR tracking, MR profiling, and active field inhomogeneity, use some form of electrical coil built into the instrument. The potential for obtaining high-resolution images of the vessel wall using coils built into a catheter is also discussed. These images provide the capability to distinguish and identify various plaque components. The additional capabilities of MRI could potentially open up new applications beyond those currently performed under X-ray fluoroscopic guidance. (orig.) [de

  10. MR angiography of the abdomen

    International Nuclear Information System (INIS)

    Johnson, C.D.; Ehman, R.L.

    1989-01-01

    Recent developments in MR imaging have included projection images of vascular anatomy. One approach for obtaining these images was based on computer raytracing through a volume set of tomographic source sections in which vascular structures had high signal intensity. The authors investigated whether the final projecting images provided diagnostic information that could not be appreciated in the original (source) tomographic sections. Angiographic images were obtained in 15 patients with chronic liver disease by using a time-of-flight technique based on breathhold gradient-recalled image volume data sets. Films were analyzed by studying projection angiograms alone, tomographic images alone, and both projection and tomographic images. Projection angiographic images alone provided little diagnostic information that could not be appreciated readily in the simple tomographic data sets. Many important diagnostic observations that were apparent in the tomographic images could not be appreciated in the projection MR angiograms

  11. New methods for MR angiography

    International Nuclear Information System (INIS)

    Nishimura, D.G.; Pauly, J.M.; Macovski, A.; Jackson, J.I.; Conolly, S.M.

    1986-01-01

    The authors explored several methods of projection vessel imaging suitable for coronary arteries and vessels in the head and neck. To produce a vessel signal, one subtractive method varies the time-of-flight effects of blood flowing into an imaged slab by tagging different regions between measurements. A second method avoids a subtraction operation by using a sequence of pulses designed to excite flowing blood only. Manipulation of the imaging gradients to create velocity-dependent phase or magnitude changes can augment the flow sensitivity. In humans, these methods have demonstrated excellent static material, vessel contrast, and resolution

  12. The diagnostic value of time-resolved MR angiography with Gadobutrol at 3 T for preoperative evaluation of lower extremity tumors: Comparison with computed tomography angiography

    International Nuclear Information System (INIS)

    Wu, Gang; Jin, Teng; Li, Ting; Li, Xiaoming

    2016-01-01

    To evaluate the diagnostic value of time resolved magnetic resonance angiography with interleaved stochastic trajectory (TWIST) using Gadobutrol for preoperative evaluation of lower extremity tumors. This prospective study was approved by the local Institutional Review Board. 50 consecutive patients (31 men, 19 women, age range 18–80 years, average age 42.7 years) with lower extremity tumors underwent TWIST and computed tomography angiography (CTA). Image quality of TWIST and CTA were evaluated by two radiologists according to a 4-point scale. The degree of arterial stenosis caused by tumor was assessed using TWSIT and CTA separately, and the intra-modality agreement was determined using a kappa test. The number of feeding arteries identified by TWIST was compared with that by CTA using Wilcoxon signed rank test. The ability to identify arterio-venous fistulae (AVF) were compared using a chi-square test. Image quality of TWIST and CTA were rated as 3.88 ± 0.37 and 3.97 ± 0.16, without statistically significant difference (P = 0.135). Intra-modality agreement was excellent for the assessment of arterial stenosis (kappa = 0.806 ± 0.073 for Reader 1, kappa = 0.805 ± 0.073 for Reader 2). Readers identified AVF with TWIST in 27 of 50 cases, and identified AVF with CTA in 14 of 50 (P < 0.001). Mean feeding arteries identified with TWIST was significantly more than that with CTA (2.08 ± 1.72 vs 1.62 ± 1.52, P = 0.02). TWIST is a reliable imaging modality for the assessment of lower extremity tumors. TWIST is comparable to CTA for the identification of AVF and feeding arteries

  13. Noncontrast MR angiography (MRA) of infragenual arteries using flow-sensitive dephasing (FSD)-prepared steady-state free precession (SSFP) at 3.0 Tesla: Comparison with contrast-enhanced MRA.

    Science.gov (United States)

    Zhang, Nan; Fan, Zhaoyang; Luo, Nan; Bi, Xiaoming; Zhao, Yike; An, Jing; Liu, Jiayi; Chen, Zhong; Fan, Zhanming; Li, Debiao

    2016-02-01

    To evaluate the feasibility and diagnostic performance of flow-sensitive dephasing (FSD)-prepared steady-state free precession (SSFP) MR angiography (MRA) for imaging infragenual arteries at 3.0T, with contrast enhanced MR angiography (CE MRA) as reference. Twenty consecutive patients with suspicion of lower extremity arterial disease undergoing routine CE MRA were recruited. FSD MRA was performed at calf before CE MRA. Image quality and stenosis degree of infragenual arteries from both techniques were independently evaluated and compared. Six patients in this study underwent DSA examination. Three undiagnostic segments were excluded with severe venous contamination in CE MRA. A total of 197 calf arterial segments images were analyzed. No significant difference existed in the relative signal intensity (rSI) of arterial segments between FSD MRA and CE MRA techniques (0.92 ± 0.09 versus 0.93 ± 0.05; P = 0.207). However, the subjective image quality score was slightly higher in FSD MRA (3.66 ± 0.81 versus 3.49 ± 0.87; P = 0.050). With CE MRA images as reference standard, slight overestimation existed in FSD MRA (2.19 ± 1.24 versus 2.09 ± 1.18; P = 0.019), with total agreement of 84.3% on the basis of all arterial segments. The sensitivity, specificity, negative predictive value, and positive predictive value of FSD MRA was 96.4%, 93.0%, 98.5%, and 84.1%. No significant difference in the stenosis degree score was detected between MRA (FSD MRA and CE MRA) and DSA (P > 0.05). FSD MRA performed on at 3.0T without the use of contrast medium provides diagnostic images allowing for arterial stenosis assessment of calf arteries that was highly comparable with CE MRA. Moreover, venous contamination was less problematic with FSD MRA. © 2015 Wiley Periodicals, Inc.

  14. Evaluation of Contrast MR Angiography in the Study of Internal Carotid Artery Stenosis. Systematic Review of the Literature; Evaluacion de la estenosis de la arteria carotida interna por angiografia REM con contraste: revision sistematica de la bibliografia

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Perez, P.; Martinez Cantarero, J. [Hospital Universitario 12 de Octubre. Madrid (Spain); Ruiz Diaz, M.; Blazquez Morera, J. A. [Universidad Autonoma de Madrid (Spain); Llano Senaris, J. E. de [Fundacion Gaspar Casal. Madrid (Spain)

    2004-07-01

    To evaluate the diagnostic benefit of using contrast MR Angiography (MRA) in the study of extracranial internal carotid artery stenosis as opposed to intraarterial digital subtraction arteriography (LADSA). A search for relevant articles from 1990 to 2000 using MDLINE and EMBASE databases. Initial selection criteria: 1. articles which compare MRA and IADSA in the study of extracranial internal carotid artery stenosis; and 2, sample size of 10 or more subjects. Studies employing contrast MRA were subsequently selected. Contrast MRA diagnostic results were studied, as were those of non-contrast MRA (TOF) if included. Roc curves and 95% confidence intervals were calculated. In the studies, 324 patients and 648 extracranial internal carotid arteries were evaluated (12 articles). The diagnostic results in carotid artery stenosis discrimination using contrast MRA as opposed to IADSA were sensitivity and specificity=97.28% and 96.08%. With regard to contrast MRA vs. non-contrast MRA (TOF), significant differences favoring contrast MRA in both sensitivity and specificity were observed. (p=0.08 and p<0.001, respectively). MRA techniques demonstrate very high diagnostic capabilities in the detection of carotid stenosis, with contrast MRA being more effective than non-contrast. MRA. In spite of not being superior to IADSA, given the morbimortality risk which the latter is associated (0.7-1.2%). many authors defend contrast MRA (in association with Doppler echography) having become the method of choice for presurgical study of extracranial internal carotid artery stenosis. (Author) 53 refs.

  15. Bilateral ce-MR angiography of the hands at 3.0 T and 1.5 T: intraindividual comparison of quantitative and qualitative image parameters in healthy volunteers

    International Nuclear Information System (INIS)

    Winterer, Jan T.; Markl, Michael; Frydrychowicz, Alexander; Bley, Thorsten A.; Langer, Mathias; Moske-Eick, Olaf

    2008-01-01

    The purpose of this study was to determine the benefit of bilateral contrast-enhanced MR angiography (ce-MRA) of the hands at 3.0 Tesla (T) compared with an established 1.5-T technique in healthy volunteers. Intraindividual bilateral ce-MRA of the hands was performed at 1.5 T and 3.0 T in 14 healthy volunteers using a timed ultra-fast GRE sequence featuring parallel acquisition. The evaluation comprised measurement of the vessel signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR), rating of the image quality and the assessment of artefacts and venous contamination. At 3.0 T, SNR improved up to 95% and CNR up to 129%. The image quality of the larger inflow arteries, the palm arches and common digital arteries was good or sufficient at either magnetic field strengths. However, 3.0-T MRA was clearly superior in the depiction of the digital arteries. Ce-MRA of the hand clearly profits from the use of 3.0 T. Compared with 1.5 T, a substantial increase of CNR is found resulting in a significantly better delineation of the small digital arteries. Saturation affects more the SNR of the perivascular tissue than the contrast-enhanced blood, and thus leads to a marked increase of CNR at 3.0. (orig.)

  16. 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....

  17. 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 ...

  18. 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 ...

  19. 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 ...

  20. 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

  1. 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).

  2. Non-contrast-enhanced 4D MR angiography with STAR spin labeling and variable flip angle sampling: a feasibility study for the assessment of Dural Arteriovenous Fistula

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Jinhee; Kim, Bom-yi; Choi, Hyun Seok; Jung, So-Lyung; Ahn, Kook-Jin; Kim, Bum-soo [The Catholic University of Korea, Department of Radiology, Seoul St. Mary' s Hospital, College of Medicine, Seoul (Korea, Republic of); Schmitt, Peter [Siemens AG, Healthcare Sector, Erlangen (Germany); Kim, Inseong; Paek, Munyoung [Siemens AG, Healthcare, Seoul (Korea, Republic of)

    2014-04-15

    This study aimed to evaluate the feasibility of non-contrast-enhanced 4D magnetic resonance angiography (NCE 4D MRA) with signal targeting with alternative radiofrequency (STAR) spin labeling and variable flip angle (VFA) sampling in the assessment of dural arteriovenous fistula (DAVF) in the transverse sinus. Nine patients underwent NCE 4D MRA for the evaluation of DAVF in the transverse sinus at 3 T. One patient was examined twice, once before and once after the interventional treatment. All patients also underwent digital subtraction angiography (DSA) and/or contrast-enhanced magnetic resonance angiography (CEMRA). For the acquisition of NCE 4D MRA, a STAR spin tagging method was used, and a VFA sampling was applied in the data readout module instead of a constant flip angle. Two readers evaluated the NCE 4D MRA data for the diagnosis of DAVF and its type with consensus. The results were compared with those from DSA and/or CEMRA. All patients underwent NCE 4D MRA without any difficulty. Among seven patients with patent DAVFs, all cases showed an early visualization of the transverse sinus on NCE 4D MRA. Except for one case, the type of DAVF of NCE 4D MRA was agreed with that of reference standard study. Cortical venous reflux (CVR) was demonstrated in two cases out of three patients with CVR. NCE 4D MRA with STAR tagging and VFA sampling is technically and clinically feasible and represents a promising technique for assessment of DAVF in the transverse sinus. Further technical developments should aim at improvements of spatial and temporal coverage. (orig.)

  3. Non-contrast-enhanced 4D MR angiography with STAR spin labeling and variable flip angle sampling: a feasibility study for the assessment of Dural Arteriovenous Fistula

    International Nuclear Information System (INIS)

    Jang, Jinhee; Kim, Bom-yi; Choi, Hyun Seok; Jung, So-Lyung; Ahn, Kook-Jin; Kim, Bum-soo; Schmitt, Peter; Kim, Inseong; Paek, Munyoung

    2014-01-01

    This study aimed to evaluate the feasibility of non-contrast-enhanced 4D magnetic resonance angiography (NCE 4D MRA) with signal targeting with alternative radiofrequency (STAR) spin labeling and variable flip angle (VFA) sampling in the assessment of dural arteriovenous fistula (DAVF) in the transverse sinus. Nine patients underwent NCE 4D MRA for the evaluation of DAVF in the transverse sinus at 3 T. One patient was examined twice, once before and once after the interventional treatment. All patients also underwent digital subtraction angiography (DSA) and/or contrast-enhanced magnetic resonance angiography (CEMRA). For the acquisition of NCE 4D MRA, a STAR spin tagging method was used, and a VFA sampling was applied in the data readout module instead of a constant flip angle. Two readers evaluated the NCE 4D MRA data for the diagnosis of DAVF and its type with consensus. The results were compared with those from DSA and/or CEMRA. All patients underwent NCE 4D MRA without any difficulty. Among seven patients with patent DAVFs, all cases showed an early visualization of the transverse sinus on NCE 4D MRA. Except for one case, the type of DAVF of NCE 4D MRA was agreed with that of reference standard study. Cortical venous reflux (CVR) was demonstrated in two cases out of three patients with CVR. NCE 4D MRA with STAR tagging and VFA sampling is technically and clinically feasible and represents a promising technique for assessment of DAVF in the transverse sinus. Further technical developments should aim at improvements of spatial and temporal coverage. (orig.)

  4. Improving the image quality of contrast-enhanced MR angiography by automated image registration: A prospective study in peripheral arterial disease of the lower extremities

    International Nuclear Information System (INIS)

    Menke, Jan

    2010-01-01

    Objective: If a patient has moved during digital subtraction angiography (DSA), manual pixel shift can improve the image quality. This study investigated whether such image registration can also improve the quality of contrast-enhanced magnetic resonance angiography (MRA) in patients with peripheral arterial disease of the lower extremities. Materials and methods: 404 leg MRAs of patients likely to have peripheral artery disease were included in this prospective study. The standard non-registered MRAs were compared to automatically linear, affine and warp registered MRAs by four image quality parameters, including the vessel detection probability (VDP) in maximum intensity projection (MIP) images and contrast-to-noise ratios (CNR). The different registration types were compared by analysis of variance. Results: All studied image quality parameters showed similar trends. Generally, registration improved the leg MRA quality significantly (P < 0.05). The 12% of lower legs with a body shift of 1 mm or more showed the highest gain in image quality when using linear registration instead of no registration, with an average VDP gain of 20-49%. Warp registration improved the image quality slightly further. Conclusion: Automated image registration can improve the MRA image quality especially in the lower legs, which is comparable to the effect of pixel shift in DSA.

  5. Non-contrast-enhanced MR angiography in critical limb ischemia: performance of quiescent-interval single-shot (QISS) and TSE-based subtraction techniques

    Energy Technology Data Exchange (ETDEWEB)

    Altaha, Mustafa A. [University Health Network, Department of Medical Imaging, Peter Munk Cardiac Centre, Toronto, Ontario (Canada); Jaskolka, Jeffrey D.; Tan, Kongteng; Menezes, Ravi J. [University Health Network, Department of Medical Imaging, Peter Munk Cardiac Centre, Toronto, Ontario (Canada); University of Toronto, Department of Medical Imaging, Toronto, Ontario (Canada); Rick, Manuela; Schmitt, Peter [Siemens Healthcare, Erlangen (Germany); Wintersperger, Bernd J. [University Health Network, Department of Medical Imaging, Peter Munk Cardiac Centre, Toronto, Ontario (Canada); University of Toronto, Department of Medical Imaging, Toronto, Ontario (Canada); Toronto General Hospital, Department of Medical Imaging, Toronto, Ontario (Canada)

    2017-03-15

    The aim of this study was to evaluate diagnostic performance of non-contrast-enhanced 2D quiescent-interval single-shot (QISS) and 3D turbo spin-echo (TSE)-based subtraction magnetic resonance angiography (MRA) in the assessment of peripheral arteries in patients with critical limb ischemia (CLI). Nineteen consecutive patients (74 % male, 72.8 ± 9.9 years) with CLI underwent 2D QISS and 3D TSE-based subtraction MRA at 1.5 T. Axial-overlapping QISS MRA (3 mm/2 mm; 1 x 1 mm{sup 2}) covered from the toes to the aortic bifurcation while coronal 3D TSE-based subtraction MRA (1.3 x 1.2 x 1.3 mm{sup 3}) was restricted to the calf only. MRA data sets (two readers) were evaluated for stenosis (≥50 %) and image quality. Results were compared with digital subtraction angiography (DSA). Two hundred and sixty-seven (267) segments were available for MRA-DSA comparison, with a prevalence of stenosis ≥50 % of 41.9 %. QISS MRA was rated as good to excellent in 79.5-96.0 % of segments without any nondiagnostic segments; 89.8-96.1 % of segments in 3D TSE-based subtraction MRA were rated as nondiagnostic or poor. QISS MRA sensitivities and specificities (segmental) were 92 % and 95 %, respectively, for reader one and 81-97 % for reader two. Due to poor image quality of 3D TSE-based subtraction MRA, diagnostic performance measures were not calculated. QISS MRA demonstrates excellent diagnostic performance and higher robustness than 3D TSE-based subtraction MRA in the challenging patient population with CLI. (orig.)

  6. Non-contrast-enhanced MR angiography in critical limb ischemia: performance of quiescent-interval single-shot (QISS) and TSE-based subtraction techniques

    International Nuclear Information System (INIS)

    Altaha, Mustafa A.; Jaskolka, Jeffrey D.; Tan, Kongteng; Menezes, Ravi J.; Rick, Manuela; Schmitt, Peter; Wintersperger, Bernd J.

    2017-01-01

    The aim of this study was to evaluate diagnostic performance of non-contrast-enhanced 2D quiescent-interval single-shot (QISS) and 3D turbo spin-echo (TSE)-based subtraction magnetic resonance angiography (MRA) in the assessment of peripheral arteries in patients with critical limb ischemia (CLI). Nineteen consecutive patients (74 % male, 72.8 ± 9.9 years) with CLI underwent 2D QISS and 3D TSE-based subtraction MRA at 1.5 T. Axial-overlapping QISS MRA (3 mm/2 mm; 1 x 1 mm 2 ) covered from the toes to the aortic bifurcation while coronal 3D TSE-based subtraction MRA (1.3 x 1.2 x 1.3 mm 3 ) was restricted to the calf only. MRA data sets (two readers) were evaluated for stenosis (≥50 %) and image quality. Results were compared with digital subtraction angiography (DSA). Two hundred and sixty-seven (267) segments were available for MRA-DSA comparison, with a prevalence of stenosis ≥50 % of 41.9 %. QISS MRA was rated as good to excellent in 79.5-96.0 % of segments without any nondiagnostic segments; 89.8-96.1 % of segments in 3D TSE-based subtraction MRA were rated as nondiagnostic or poor. QISS MRA sensitivities and specificities (segmental) were 92 % and 95 %, respectively, for reader one and 81-97 % for reader two. Due to poor image quality of 3D TSE-based subtraction MRA, diagnostic performance measures were not calculated. QISS MRA demonstrates excellent diagnostic performance and higher robustness than 3D TSE-based subtraction MRA in the challenging patient population with CLI. (orig.)

  7. Brain arteriovenous malformation diagnosis: value of time-resolved contrast-enhanced MR angiography at 3.0T compared to DSA

    International Nuclear Information System (INIS)

    Machet, A.; Kadziolka, K.; Robin, G.; Lanoix, O.; Pierot, L.; Portefaix, C.

    2012-01-01

    This study was conducted in order to evaluate the value of time-resolved contrast-enhanced magnetic resonance angiography (TR-CE-MRA) with a 3.0-T magnetic field compared to digital subtraction angiography (DSA) as the reference standard for the diagnosis of brain arteriovenous malformation (bAVM). Nineteen patients with 19 angiographically confirmed untreated bAVM were investigated with both DSA and TR-CE-MRA for the initial diagnosis. Examinations were compared by two independent readers. Interobserver agreement and intermodality agreement with respect to nidus size, arterial feeders, and venous drainage were determined using the K statistic test. Also, the quality of the TR-CE-MRA images was evaluated. Seventeen of the 19 bAVM (89.5%) detected with DSA were diagnosed with TR-CE-MRA. Interobserver agreement for TR-CE-MRA was good for nidus size, venous drainage, and arterial feeders (K = 0.75, 95% CI 0.50-1.00; K = 0.77, 95% CI 0.54-1.00; and K = 0.80, 95% CI 0.59-1.00 respectively). Intermodality agreement was good for nidus size and venous drainage (K = 0.75, 95% CI 0.49-1.00 and K = 0.77, 95% CI 0.54-1.00, respectively) and moderate for arterial feeders (K = 0.44, 95% CI 0.17-0.70). TR-CE-MRA at 3.0 T has a good sensitivity for bAVM detection and good agreement with DSA for determining nidus size and the type of venous drainage, suggesting that TR-CE-MRA is potentially a reliable tool for the diagnosis and assessment of bAVMs. However, it still suffers from low spatial resolution and vessel superposition, making differentiation of the arterial feeders of the nidus difficult at times. (orig.)

  8. Preliminary study of 3.0 T contrast-enhanced whole heart coronary MR angiography using 32-channel coils with high acceleration factor

    International Nuclear Information System (INIS)

    Yang Qi; Li Kuncheng; Du Xiangying; Ma Heng; An Jing; Li Han; Xu Dong; Bi Xiaoming; Li Debiao

    2010-01-01

    Objective: To evaluate the diagnostic accuracy of 3.0 T contrast enhanced (CE) whole-heart coronary MRA (CE MRA) using 32-channel coils with high acceleration factor. Methods: Sixty patients with suspected coronary artery disease who were scheduled for coronary angiography (CAG) underwent CE CMRA at 3.0 T MRI scanner. A 32-channel receiver coil was used for data acquisition. For image acquisition, an ECG triggered,navigator-gated, inversion-recovery prepared, segmented gradient-echo sequence was used with an acceleration factor of three in the phase-encoding direction using GRAPPA reconstruction. Gd-BOPTA (0.15 mmol/kg body weight) was intravenously administered at a rate of 0.3 ml/s. The diagnostic accuracy in detecting significant stenoses (≥50% of vessel lumen) was evaluated using χ 2 test with X-ray angiography as the reference. Results: Whole-heart CE CMRA was successfully completed in 56 patients who were scheduled for CAG. The averaged imaging time was (6.0±1.3) min. 3.0 T CE CMRA using 32 channel coils correctly identified significant CAD in 28 patients and correctly ruled out CAD in 23 patients. The sensitivity and specificity were 93.3% and 88.5% respectively. Conclusion: Combined with dedicated 32-channel coils, 3.0 T CE CMRA allows significant reduction in imaging speed and reduced dose of the contrast agent. These improvements resulted in substantially improved overall accuracy of CE CMRA in detecting coronary artery disease. (authors)

  9. A fundamental study of non-contrast enhanced MR angiography using ECG gated-3D fast spin echo at 3.0 T

    International Nuclear Information System (INIS)

    Nakato, Kengo; Hiai, Yasuhiro; Tomiguchi, Seiji

    2010-01-01

    Contrast-enhanced magnetic resonance angiography (CE-MRA) is frequently performed in body and extremity studies because of its superior ability to detect the vascular stenosis. However, nephrotoxicity of the contrast medium has been emphasized in recent years. Non-contrast MRA using the three-dimensional electrocardiogram-synchronized fast spin echo method (fresh blood imaging (FBI), non-contrast MRA of arteries and veins (NATIVE) and triggered acquisition non contrast enhancement MRA (TRANCE)) is recommended as a substitute for CE-MRA. There are a few reports in the literature that evaluate the detectability of vascular stenosis using non-contrast MRA on 3.0 T MRI. The purpose of this study was to evaluate the detectability of vascular stenosis using non-contrast MRA at 3.0 T with an original vascular phantom. The vascular phantom consisted of silicon tubes. 30% and 70% stenosis of luminal diameter were made. Each silicon tube connected a pump producing a pulsatile flow. A flowing material to was used in this study to show the similarity of the intensity to blood on MRI. MRA without a contrast medium (NATIVE sequence) were performed in the vascular phantom by changing the image matrix, static magnetic field strength and flow velocity. In addition, the NATIVE sequence was used with or without flow compensation. Vascular stenosis was quantitatively estimated by measurement of the signal intensities in non-contrast MRA images. MRA with NATIVE sequence demonstrated an accurate estimation of 30% vascular stenosis at slow flow velocity. However, 30% stenosis was overestimated in cases of high flow velocity. Estimation was improved by using a flow compensation sequence. 70% stenosis was overestimated on MRA with NATIVE sequence. Estimation of 70% stenosis was improved by using a flow compensation sequence. Accurate estimation of vascular stenosis in MRA with a NATIVE sequence is improved by using the flow compensation technique. MRA with NATIVE sequence is considered to

  10. Artefacts induced by coiled intracranial aneurysms on 3.0-Tesla versus 1.5-Tesla MR angiography--An in vivo and in vitro study.

    Science.gov (United States)

    Schaafsma, Joanna D; Velthuis, Birgitta K; Vincken, Koen L; de Kort, Gerard A P; Rinkel, Gabriel J E; Bartels, Lambertus W

    2014-05-01

    To compare metal-induced artefacts from coiled intracranial aneurysms on 3.0-Tesla and 1.5-Tesla magnetic resonance angiography (MRA), since concerns persist on artefact enlargement at 3.0Tesla. We scanned 19 patients (mean age 53; 16 women) with 20 saccular aneurysms treated with coils only, at 1.5 and 3.0Tesla according to standard clinical 3D TOF-MRA protocols containing a shorter echo-time but weaker read-out gradient at 3.0Tesla in addition to intra-arterial digital subtraction angiography (IA-DSA). Per modality two neuro-radiologists assessed the occlusion status, measured residual flow, and indicated whether coil artefacts disturbed this assessment on MRA. We assessed relative risks for disturbance by coil artefacts, weighted kappa's for agreement on occlusion levels, and we compared remnant sizes. For artefact measurements, a coil model was created and scanned with the same protocols followed by 2D MR scans with variation of echo-time and read-out gradient strength. Coil artefacts disturbed assessments less frequently at 3.0Tesla than at 1.5Tesla (RR: 0.3; 95%CI: 0.1-0.8). On 3.0-Tesla MRA, remnants were larger than on 1.5-Tesla MRA (difference: 0.7mm; 95%CI: 0.3-1.1) and larger than on IA-DSA (difference: 1.0mm; 95%CI: 0.6-1.5) with similar agreement on occlusion levels with IA-DSA for both field strengths (κ 0.53; 95%CI: 0.23-0.84 for 1.5-Tesla MRA and IA-DSA; κ 0.47; 95%CI: 0.19-0.76 for 3.0-Tesla MRA and IA-DSA). Coil model artefacts were smaller at 3.0Tesla than at 1.5Tesla. The echo-time influenced artefact size more than the read-out gradient. Artefacts were not larger, but smaller at 3.0Tesla because a shorter echo-time at 3.0Tesla negated artefact enlargement. Despite smaller artefacts and larger remnants at 3.0Tesla, occlusion levels were similar for both field strengths. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  11. Clinical impact of preoperative brain MR angiography and MR imaging in candidates for liver transplantation: a propensity score-matching study in a single institution

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Mi Sun; Kim, Ho Sung; Jung, Seung Chai; Choi, Choong Gon; Kim, Sang Joon [University of Ulsan College of Medicine, Department of Radiology and Research Institute of Radiology, Song pa-gu, Seoul (Korea, Republic of); Lim, Young-Suk [University of Ulsan College of Medicine, Department of Gastroenterology, Seoul (Korea, Republic of); Jeon, Sang-Beom [University of Ulsan College of Medicine, Department of Neurology, Seoul (Korea, Republic of); Kim, Seon-Ok [University of Ulsan College of Medicine, Department of Clinical Epidemiology and Biostatistics, Seoul (Korea, Republic of); Kim, Hwa Jung [University of Ulsan College of Medicine, Department of Preventive Medicine, Seoul (Korea, Republic of); Hwang, Shin [University of Ulsan College of Medicine, Division of Liver Transplantation and Hepatobiliary Surgery, Department of Surgery, Seoul (Korea, Republic of)

    2017-08-15

    To investigate the prevalence of cerebrovascular stenosis and white matter lesions on preoperative magnetic resonance angiography (MRA) and magnetic resonance imaging (MRI) in liver transplantation candidates. This retrospective study included 1,460 consecutive patients with liver cirrhosis (LC) who underwent MRA with/without brain MRI for pretransplantation evaluation. These patients were matched with 5,331 controls using propensity scores, and the prevalences of significant cerebrovascular stenosis and white matter lesions were compared. A matched analysis of 1,264 pairs demonstrated that the prevalence of significant stenosis was comparable between LC patients and controls (2.2% vs. 1.4%, P = 0.143). LC and most of LC-related parameters were not associated with stenosis. Significant white matter lesions were more common in LC patients (2.8% vs. 1.3%, P = 0.036). A high Model for End-Stage Liver Disease (MELD) score (OR 1.11, CI 1.03-1.20, P = 0.008, for infarction; OR 1.1, CI 1.04-1.16, P = 0.001, for haemorrhage) and stroke history (OR 179.06, CI 45.19-709.45, P < 0.001) were predictors of perioperative stroke. LC patients and control subjects demonstrated similar cerebrovascular stenosis prevalences, whereas white matter lesions were more common in LC patients. A high MELD score and stroke history contribute as predictors of perioperative stroke. (orig.)

  12. T2*-weighted MR angiography substantially increases the detection of hemorrhage in the wall of brain abscess: implications in clinical interpretation

    International Nuclear Information System (INIS)

    Gupta, Rakesh Kumar; Tomar, Vaishali; Awasthi, Rishi; Yadav, Abhishek; Husain, Nuzhat; Bharadwaj, Vikas; Ojha, Bal K.; Behari, Sanjay; Prasad, Kashi N.; Singh Rathore, Ram Kishore

    2012-01-01

    The purpose of the present study was to identify the true prevalence of hemorrhage in the abscess using T2*-weighted angiography (SWAN) imaging and to study its influence on diffusion tensor imaging (DTI) metrics. Fifteen patients of brain abscess underwent conventional, SWAN, and DT imaging on a 3-T MRI followed by its confirmation with histology. DTI metrics were quantified by region-of-interest analysis on hemorrhagic and non-hemorrhagic regions of the abscess wall. Prussian blue staining was performed on excised abscess walls to confirm hemorrhage on histology. Eleven of 15 patients showed evidence of hemorrhage on both Prussian blue staining as well as SWAN imaging. Fractional anisotropy (FA) and linear anisotropy (CL) values were significantly higher, while spherical anisotropy was significantly lower in hemorrhagic compared to non-hemorrhagic regions of the abscess wall. Hemorrhage in the abscess wall is a common feature and may not always indicate neoplasm. The presence of intracellular iron in addition to concentrically laid collagen fibers may have synergistic effect on FA and CL values in the abscess wall. Inclusion of SWAN to MRI protocol will define the true prevalence of hemorrhage in brain abscess. (orig.)

  13. Detailed imaging of the normal anatomy and pathologic conditions of the cavernous region at 3 Tesla using a contrast-enhanced MR angiography

    Energy Technology Data Exchange (ETDEWEB)

    Linn, Jennifer; Peters, Friederike; Lummel, Nina; Brueckmann, Hartmut; Yousry, Indra [University Hospital Munich, Department of Neuroradiology, Munich (Germany); Schankin, Christoph [University Hospital Munich, Department of Neurology, Munich (Germany); Rachinger, Walter [University Hospital Munich, Department of Neurosurgery, Munich (Germany)

    2011-12-15

    The purpose of this study was to evaluate the potential of a high-resolution contrast-enhanced magnetic resonance angiography (CE-MRA) at 3 Tesla for the delineation of the cavernous sinus (CS) anatomy both under normal and under pathological conditions. Fifteen patients without pathologies in the CS and ten patients with pituitary adenomas were included. The CE-MRA was performed on a 3-Tesla scanner and analyzed collaboratively by two readers. The cranial nerves (CNs) within the CS, namely CNIII, CNIV, CNV1, CNV2, and CNVI, were identified in both patient groups. In the adenoma patients it was also assessed whether and to which extend the adenoma invaded the CS and the spatial relationship between tumor and CNs was determined. In the patients with normal CS anatomy, CNIII could be identified in 100%, CNIV in 86.7%, and CNV1, CNV2, as well as CNVI in 100% of analyzed sides. Pituitary adenomas invaded the CS unilaterally (right side) in four patients, and bilaterally in six patients. In patients with adenomas, the CN could be identified and differentiated from the tumor in the following percentages: CNIII in 100%, CNIV in 70%, both CNV1 and CNV2 in 90%, and CNVI in 100%. In all these cases, the tumor-nerve spatial relationship could be visualized. 3-Tesla CE-MRA allows detailed imaging of the complex anatomy of the CS and its structures. In adenoma patients, it clearly visualizes the spatial relationship between tumor and CNs, and thus might be helpful to optimize presurgical planning. (orig.)

  14. Cerebral Hemodynamics in Patients with Hemolytic Uremic Syndrome Assessed by Susceptibility Weighted Imaging and Four-Dimensional Non-Contrast MR Angiography.

    Science.gov (United States)

    Löbel, Ulrike; Forkert, Nils Daniel; Schmitt, Peter; Dohrmann, Thorsten; Schroeder, Maria; Magnus, Tim; Kluge, Stefan; Weiler-Normann, Christina; Bi, Xiaoming; Fiehler, Jens; Sedlacik, Jan

    2016-01-01

    Conventional magnetic resonance imaging (MRI) of patients with hemolytic uremic syndrome (HUS) and neurological symptoms performed during an epidemic outbreak of Escherichia coli O104:H4 in Northern Europe has previously shown pathological changes in only approximately 50% of patients. In contrast, susceptibility-weighted imaging (SWI) revealed a loss of venous contrast in a large number of patients. We hypothesized that this observation may be due to an increase in cerebral blood flow (CBF) and aimed to identify a plausible cause. Baseline 1.5T MRI scans of 36 patients (female, 26; male, 10; mean age, 38.2±19.3 years) were evaluated. Venous contrast was rated on standard SWI minimum intensity projections. A prototype four-dimensional (time resolved) magnetic resonance angiography (4D MRA) assessed cerebral hemodynamics by global time-to-peak (TTP), as a surrogate marker for CBF. Clinical parameters studied were hemoglobin, hematocrit, creatinine, urea levels, blood pressure, heart rate, and end-tidal CO2. SWI venous contrast was abnormally low in 33 of 36 patients. TTP ranged from 3.7 to 10.2 frames (mean, 7.9 ± 1.4). Hemoglobin at the time of MRI (n = 35) was decreased in all patients (range, 5.0 to 12.6 g/dL; mean, 8.2 ± 1.4); hematocrit (n = 33) was abnormally low in all but a single patient (range, 14.3 to 37.2%; mean, 23.7 ± 4.2). Creatinine was abnormally high in 30 of 36 patients (83%) (range, 0.8 to 9.7; mean, 3.7 ± 2.2). SWI venous contrast correlated significantly with hemoglobin (r = 0.52, P = 0.0015), hematocrit (r = 0.65, P effect of blood transfusions in patients with HUS and neurological symptoms.

  15. High-resolution blood-pool-contrast-enhanced MR angiography in glioblastoma: tumor-associated neovascularization as a biomarker for patient survival. A preliminary study

    Energy Technology Data Exchange (ETDEWEB)

    Puig, Josep; Blasco, Gerard; Remollo, Sebastian; Hernandez, David; Pedraza, Salvador [Hospital Universitari Dr Josep Trueta, Research Unit of Diagnostic Imaging Institute (IDI), Department of Radiology [Girona Biomedical Research Institute] IDIBGI, Girona (Spain); Daunis-i-Estadella, Josep; Mateu, Gloria [University of Girona, Department of Computer Science, Applied Mathematics and Statistics, Girona (Spain); Alberich-Bayarri, Angel [La Fe Polytechnics and University Hospital, Biomedical Imaging Research Group (GIBI230), La Fe Health Research Institute, Valencia (Spain); Essig, Marco [University of Manitoba, Department of Radiology, Winnipeg (Canada); Jain, Rajan [NYU School of Medicine, Division of Neuroradiology, Department of Radiology, New York, NY (United States); Puigdemont, Montserrat [Hospital Universitari Dr Josep Trueta, Catalan Institute of Oncology (ICO), Hospital Cancer Registry, Girona (Spain); Sanchez-Gonzalez, Javier [Philips Healthcare Iberica, Madrid (Spain); Wintermark, Max [Stanford University, Department of Radiology, Neuroradiology Division, Palo Alto, CA (United States)

    2016-01-15

    The objective of the study was to determine whether tumor-associated neovascularization on high-resolution gadofosveset-enhanced magnetic resonance angiography (MRA) is a useful biomarker for predicting survival in patients with newly diagnosed glioblastomas. Before treatment, 35 patients (25 men; mean age, 64 ± 14 years) with glioblastoma underwent MRI including first-pass dynamic susceptibility contrast (DSC) perfusion and post-contrast T1WI sequences with gadobutrol (0.1 mmol/kg) and, 48 h later, high-resolution MRA with gadofosveset (0.03 mmol/kg). Volumes of interest for contrast-enhancing lesion (CEL), non-CEL, and contralateral normal-appearing white matter were obtained, and DSC perfusion and DWI parameters were evaluated. Prognostic factors were assessed by Kaplan-Meier survival and Cox proportional hazards model. Eighteen (51.42 %) glioblastomas were hypervascular on high-resolution MRA. Hypervascular glioblastomas were associated with higher CEL volume and lower Karnofsky score. Median survival rates for patients with hypovascular and hypervascular glioblastomas treated with surgery, radiotherapy, and chemotherapy were 15 and 9.75 months, respectively (P < 0.001). Tumor-associated neovascularization was the best predictor of survival at 5.25 months (AUC = 0.794, 81.2 % sensitivity, 77.8 % specificity, 76.5 % positive predictive value, 82.4 % negative predictive value) and yielded the highest hazard ratio (P < 0.001). Tumor-associated neovascularization detected on high-resolution blood-pool-contrast-enhanced MRA of newly diagnosed glioblastoma seems to be a useful biomarker that correlates with worse survival. (orig.)

  16. Detailed imaging of the normal anatomy and pathologic conditions of the cavernous region at 3 Tesla using a contrast-enhanced MR angiography

    International Nuclear Information System (INIS)

    Linn, Jennifer; Peters, Friederike; Lummel, Nina; Brueckmann, Hartmut; Yousry, Indra; Schankin, Christoph; Rachinger, Walter

    2011-01-01

    The purpose of this study was to evaluate the potential of a high-resolution contrast-enhanced magnetic resonance angiography (CE-MRA) at 3 Tesla for the delineation of the cavernous sinus (CS) anatomy both under normal and under pathological conditions. Fifteen patients without pathologies in the CS and ten patients with pituitary adenomas were included. The CE-MRA was performed on a 3-Tesla scanner and analyzed collaboratively by two readers. The cranial nerves (CNs) within the CS, namely CNIII, CNIV, CNV1, CNV2, and CNVI, were identified in both patient groups. In the adenoma patients it was also assessed whether and to which extend the adenoma invaded the CS and the spatial relationship between tumor and CNs was determined. In the patients with normal CS anatomy, CNIII could be identified in 100%, CNIV in 86.7%, and CNV1, CNV2, as well as CNVI in 100% of analyzed sides. Pituitary adenomas invaded the CS unilaterally (right side) in four patients, and bilaterally in six patients. In patients with adenomas, the CN could be identified and differentiated from the tumor in the following percentages: CNIII in 100%, CNIV in 70%, both CNV1 and CNV2 in 90%, and CNVI in 100%. In all these cases, the tumor-nerve spatial relationship could be visualized. 3-Tesla CE-MRA allows detailed imaging of the complex anatomy of the CS and its structures. In adenoma patients, it clearly visualizes the spatial relationship between tumor and CNs, and thus might be helpful to optimize presurgical planning. (orig.)

  17. Clinical study on relationship of visualization of the cerebral arteries in MR angiography to age, sex, laterality or lacunar infarction in neurologically normal subjects

    International Nuclear Information System (INIS)

    Kajiya, Yoriko

    1995-01-01

    The purpose of this study is to assess the correlation between the visualization of cerebral peripheral arteries in magnetic resonance angiography (MRA) and aging, sex, laterality or lacunar infarctions in magnetic resonance imaging (MRI). Two hundred forty-four neurologically normal subjects (119 males and 125 females, aged 7 to 82 yrs.) were evaluated with MRA and MRI. A three-dimensional Fourier transformation (3DFT-TOF) pulse sequence with slab thickness of 115 mm was used to obtain axial, sagittal and coronal projection images. The imaging parameters were 30/11/1 (TR/TE/excitations) using a 20 degree flip angle and the voxel size was 0.9 x 1.1 x 0.9 mm. A total of 6 arteries including bilateral anterior cerebral arteries (ACAs), middle cerebral arteries (MCAs) and posterior cerebral arteries (PCAs) for every subject were each graded into 8 scores by the degree of visualization of the arteries. Asymptomatic lacunar infarctions were analyzed in subjects of fifties or more. They were scored as 0-2 based on their size and the scores were summed. An age-related decline of visualization of the cerebral arteries was observed in ACA (r=-0.603, p<0.001), MCA (r=-0.452, p<0.001) and PCA (r=-0.537, p<0.001). Females during the fifth decade had a higher score of visualization of the arteries than males (p<0.01). No substantial relationship was observed between visualization of the arteries and sex in other decades, laterality or lacunar infarctions. The MRA using a 3DFT-TOF pulse sequence with slab thickness of 115 mm disclosed an age-related decline of visualization of the cerebral arteries and a sex-dependent difference of the visualization in the fifth decade probably due to the decline of the blood flow velocity with aging and a difference in it between females and males in the fifth decade, respectively. (J.P.N.)

  18. Clinical study on relationship of visualization of the cerebral arteries in MR angiography to age, sex, laterality or lacunar infarction in neurologically normal subjects

    Energy Technology Data Exchange (ETDEWEB)

    Kajiya, Yoriko [Kagoshima Univ. (Japan). Faculty of Medicine

    1995-08-01

    The purpose of this study is to assess the correlation between the visualization of cerebral peripheral arteries in magnetic resonance angiography (MRA) and aging, sex, laterality or lacunar infarctions in magnetic resonance imaging (MRI). Two hundred forty-four neurologically normal subjects (119 males and 125 females, aged 7 to 82 yrs.) were evaluated with MRA and MRI. A three-dimensional Fourier transformation (3DFT-TOF) pulse sequence with slab thickness of 115 mm was used to obtain axial, sagittal and coronal projection images. The imaging parameters were 30/11/1 (TR/TE/excitations) using a 20 degree flip angle and the voxel size was 0.9 x 1.1 x 0.9 mm. A total of 6 arteries including bilateral anterior cerebral arteries (ACAs), middle cerebral arteries (MCAs) and posterior cerebral arteries (PCAs) for every subject were each graded into 8 scores by the degree of visualization of the arteries. Asymptomatic lacunar infarctions were analyzed in subjects of fifties or more. They were scored as 0-2 based on their size and the scores were summed. An age-related decline of visualization of the cerebral arteries was observed in ACA (r=-0.603, p<0.001), MCA (r=-0.452, p<0.001) and PCA (r=-0.537, p<0.001). Females during the fifth decade had a higher score of visualization of the arteries than males (p<0.01). No substantial relationship was observed between visualization of the arteries and sex in other decades, laterality or lacunar infarctions. The MRA using a 3DFT-TOF pulse sequence with slab thickness of 115 mm disclosed an age-related decline of visualization of the cerebral arteries and a sex-dependent difference of the visualization in the fifth decade probably due to the decline of the blood flow velocity with aging and a difference in it between females and males in the fifth decade, respectively. (J.P.N.).

  19. 3D Whole-Heart Coronary MR Angiography at 1.5T in Healthy Volunteers: Comparison between Unenhanced SSFP and Gd-Enhanced FLASH Sequences

    International Nuclear Information System (INIS)

    Gweon, Hye Mi; Kim, Sang Jin; Lee, Sang Min; Hong, Yoo Jin; Kim, Tae Hoon

    2011-01-01

    To validate the optimal cardiac phase and appropriate acquisition window for three-dimensional (3D) whole-heart coronary magnetic resonance angiography (MRA) with a steady-state free precession (SSFP) sequence, and to compare image quality between SSFP and Gd-enhanced fast low-angle shot (FLASH) MR techniques at 1.5 Tesla (T). Thirty healthy volunteers (M:F 25:5; mean age, 35 years; range, 24-54 years) underwent a coronary MRA at 1.5T. 3D whole-heart coronary MRA with an SSFP was performed at three different times: 1) at end-systole with a narrow (120-msec) acquisition window (ESN), 2) mid-diastole with narrow acquisition (MDN); and 3) mid-diastole with wide (170-msec) acquisition (MDW). All volunteers underwent a contrast enhanced coronary MRA after undergoing an unenhanced 3D true fast imaging with steady-state precession (FISP) MRA three times. A contrast enhanced coronary MRA with FLASH was performed during MDN. Visibility of the coronary artery and image quality were evaluated for 11 segments, as suggested by the American Heart Association. Image quality was scored by a five-point scale (1 = not visible to 5 = excellent). The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were evaluated at the proximal coronary arteries. The SSFP sequence rendered higher visibility coronary segments, higher image quality, as well as higher SNR and CNR than the Gd-enhanced FLASH technique at 1.5T (p < 0.05). The visibility of coronary segments, image quality, SNR and CNR in the ESN, MDN and MDW with SSFP sequence did not differ significantly. An SSFP sequence provides an excellent method for the 3D whole-heart coronary MRA at 1.5T. Contrast enhanced coronary MRA using the FLASH sequence does not help improve the visibility of coronary segments, image quality, SNR or CNR on the 3D whole-heart coronary MRA.

  20. ECG-gated quiescent-interval single-shot MR angiography of the lower extremities: Initial experience at 3 T

    International Nuclear Information System (INIS)

    Knobloch, G.; Gielen, M.; Lauff, M.-T.; Romano, V.C.; Schmitt, P.; Rick, M.; Kröncke, T.J.; Huppertz, A.; Hamm, B.; Wagner, M.

    2014-01-01

    Aim: To evaluate the feasibility of unenhanced electrocardiography (ECG)-gated quiescent-interval single-shot magnetic resonance angiography (QISS-MRA) of the lower extremities at 3 T. Materials and methods: Twenty-five patients with known or suspected peripheral arterial disease underwent ECG-gated QISS-MRA and contrast-enhanced MRA (CE-MRA) at 3 T. Two independent readers performed a per-segment evaluation of the MRA datasets. Image quality was rated on a four-point scale (1 = excellent to 4 = non-diagnostic; presented as medians with interquartile range). Diagnostic performance of QISS-MRA was evaluated using CE-MRA as the reference standard. Results: QISS-MRA and CE-MRA of all patients were considered for analysis, resulting in 807 evaluated vessel segments for each MRA technique. Readers 1 and 2 rated image quality of QISS-MRA as diagnostic in 97.3% and 97% of the vessel segments, respectively. CE-MRA was rated diagnostic in all vessel segments. Image quality of the proximal vessel segments, including the infrarenal aorta, iliac arteries, and common femoral artery, was significantly lower on QISS-MRA compared to CE-MRA [image quality score across readers: 2 (1,3) versus 1 (1,1) p < 0.001]. In the more distal vessel segments, image quality of QISS-MRA was excellent and showed no significant difference compared to CE-MRA [image quality score across readers: 1 (1,1) versus 1 (1,1) p = 0.036]. Diagnostic performance of QISS-MRA was as follows (across readers): sensitivity: 87.5% (95% CI: 80.2–92.4%); specificity: 96.1% (95% CI: 93.6–97.6%); diagnostic accuracy: 94.9% (95% CI: 92.6–96.5%). Conclusions: QISS-MRA of the lower extremities is feasible at 3 T and provides high image quality, especially in the distal vessel segments

  1. A comparison of four dimensional time-resolved with keyhole and three dimensional time-of-flight MR angiography for the evaluation of cerebral aneurysms

    International Nuclear Information System (INIS)

    Wu Qian; Li Minghua; Zhang Jiayin; Li Yongdong

    2012-01-01

    Objective: To evaluate the accuracy and reliability of 4D time-resolved MRA with keyhole (4D-TRAK) for the detection and characterization of cerebral aneurysms (CAs), with a comparison of 3D time-of-flight MRA (3D-TOF-MRA). Methods: 3D-TOF-MRA, 4D-TRAK and 3D-DSA were performed sequentially in 52 patients with suspected CAs. 4D-TRAK was acquired using a combination of sensitivity encoding (SENSE) and contrast-enhanced (CE) timing robust angiography (CENTRA) k-space sampling techniques at a contrast dose of 10 ml at 3 T scanner. Accuracy, sensitivity, specificity of 4D-TRAK and 3D-TOF-MRA were calculated and compared for the detection of CAs on patient-based and aneurysm-based evaluation using 3D-DSA as a reference. Wilcoxon signed rank test were used. Results: The overall image quality of 4D-TRAK was appropriate for the diagnostic purpose, but yet not comparable with that of 3D-TOF-MRA. In 52 patients with suspected GAs, 58 CAs were confirmed on 3D-DSA finally.Fifty-one (with 2 false-positives and 9 false-negatives) and 58 (with 1 false-positive and 1 false-negative) CAs were visualized on 4D-TRAK and 3D-TOF-MRA, respectively. Accuracy, sensitivity and specificity on patient-based evaluation of 4D-TRAK and 3D-TOF-MRA were 92.31% (48/52), 93.33% (42/45), 85.71 % (6/7) and 98.08% (51/52), 100.00% (45/45), 85.71% (6/7), respectively, and 74.07% (20/27), 75.00% (18/24), 66.67% (2/3) and 96.30% (26/27), 95.83% (26/27), 100.00% (3/3) on aneurysm-based evaluation in patients with multiple CAs, respectively. Subgroup analysis revealed that for 19 very small CAs (maximal diameter <3 mm,measured on 3D-DSA), 9 were missed on 4D-TRAK and 1 on 3D-TOF-MRA (Z=-2.464, P0.05). In 4 large CAs with maximal diameter more than 10 mm, 4D-TRAK provided a better characterization of morphology than 3D

  2. Cerebral Hemodynamics in Patients with Hemolytic Uremic Syndrome Assessed by Susceptibility Weighted Imaging and Four-Dimensional Non-Contrast MR Angiography.

    Directory of Open Access Journals (Sweden)

    Ulrike Löbel

    Full Text Available Conventional magnetic resonance imaging (MRI of patients with hemolytic uremic syndrome (HUS and neurological symptoms performed during an epidemic outbreak of Escherichia coli O104:H4 in Northern Europe has previously shown pathological changes in only approximately 50% of patients. In contrast, susceptibility-weighted imaging (SWI revealed a loss of venous contrast in a large number of patients. We hypothesized that this observation may be due to an increase in cerebral blood flow (CBF and aimed to identify a plausible cause.Baseline 1.5T MRI scans of 36 patients (female, 26; male, 10; mean age, 38.2±19.3 years were evaluated. Venous contrast was rated on standard SWI minimum intensity projections. A prototype four-dimensional (time resolved magnetic resonance angiography (4D MRA assessed cerebral hemodynamics by global time-to-peak (TTP, as a surrogate marker for CBF. Clinical parameters studied were hemoglobin, hematocrit, creatinine, urea levels, blood pressure, heart rate, and end-tidal CO2.SWI venous contrast was abnormally low in 33 of 36 patients. TTP ranged from 3.7 to 10.2 frames (mean, 7.9 ± 1.4. Hemoglobin at the time of MRI (n = 35 was decreased in all patients (range, 5.0 to 12.6 g/dL; mean, 8.2 ± 1.4; hematocrit (n = 33 was abnormally low in all but a single patient (range, 14.3 to 37.2%; mean, 23.7 ± 4.2. Creatinine was abnormally high in 30 of 36 patients (83% (range, 0.8 to 9.7; mean, 3.7 ± 2.2. SWI venous contrast correlated significantly with hemoglobin (r = 0.52, P = 0.0015, hematocrit (r = 0.65, P < 0.001, and TTP (r = 0.35, P = 0.036. No correlation of SWI with blood pressure, heart rate, end-tidal CO2, creatinine, and urea level was observed. Findings suggest that the loss of venous contrast is related to an increase in CBF secondary to severe anemia related to HUS. SWI contrast of patients with pathological conventional MRI findings was significantly lower compared to patients with normal MRI (mean SWI score, 1

  3. Subtraction MR venography acquired from time-resolved contrast-enhanced MR angiography: Comparison with phase-contrast MR venography and single-phase contrast-enhanced MR venography

    International Nuclear Information System (INIS)

    Jang, Jin Hee; Kim, Bum Soo; KIm, Bom Yi; Choi, Hyun Seok; Jung, So Lyung; Ahn, Kook Jin; Sung, Ji Kyeong

    2015-01-01

    To evaluate the image characteristics of subtraction magnetic resonance venography (SMRV) from time-resolved contrast-enhanced MR angiography (TRMRA) compared with phase-contrast MR venography (PCMRV) and single-phase contrast-enhanced MR venography (CEMRV). Twenty-one patients who underwent brain MR venography (MRV) using standard protocols (PCMRV, CEMRV, and TRMRA) were included. SMRV was made by subtracting the arterial phase data from the venous phase data in TRMRA. Co-registration and subtraction of the two volume data was done using commercially available software. Image quality and the degree of arterial contamination of the three MRVs were compared. In the three MRVs, 19 pre-defined venous structures (14 dural sinuses and 5 cerebral veins) were evaluated. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of the three MRVs were also compared. Single-phase contrast-enhanced MR venography showed better image quality (median score 4 in both reviewers) than did the other two MRVs (p < 0.001), whereas SMRV (median score 3 in both reviewers) and PCMRV (median score 3 in both reviewers) had similar image quality (p ≥ 0.951). SMRV (median score 0 in both reviewers) suppressed arterial signal better than did the other MRVs (median score 1 in CEMRV, median score 2 in PCMRV, both reviewers) (p < 0.001). The dural sinus score of SMRV (median and interquartile range [IQR] 48, 43-50 for reviewer 1, 47, 43-49 for reviewer 2) was significantly higher than for PCMRV (median and IQR 31, 25-34 for reviewer 1, 30, 23-32 for reviewer 2) (p < 0.01) and did not differ from that of CEMRV (median and IQR 50, 47-52 for reviewer 1, 49, 45-51 for reviewer 2) (p = 0.146 in reviewer 1 and 0.123 in reviewer 2). The SNR and CNR of SMRV (median and IQR 104.5, 83.1-121.2 and 104.1, 74.9-120.5, respectively) were between those of CEMRV (median and IQR 150.3, 111-182.6 and 148.4, 108-178.2) and PCMRV (median and IQR 59.4, 49.2-74.9 and 53.6, 43.8-69.2). Subtraction magnetic

  4. Contrast-enhanced MR angiography of the carotid artery using 3D time-resolved imaging of contrast kinetics. Comparison with real-time fluoroscopic triggered 3D-elliptical centric view ordering

    International Nuclear Information System (INIS)

    Naganawa, Shinji; Koshikawa, Tokiko; Fukatsu, Hiroshi; Sakurai, Yasuo; Ishiguchi, Tsuneo; Ishigaki, Takeo; Ichinose, Nobuyasu

    2001-01-01

    The purpose of this study was to evaluate contrast-enhanced MR angiography using the 3D time-resolved imaging of contrast kinetics technique (3D-TRICKS) by direct comparison with the fluoroscopic triggered 3D-elliptical centric view ordering (3D-ELLIP) technique. 3D-TRICKS and 3D-ELLIP were directly compared on a 1.5-Tesla MR unit using the same spatial resolution and matrix. In 3D-TRICKS, the central part of the k-space is updated more frequently than the peripheral part of the k-space, which is divided in the slice-encoding direction. The carotid arteries were imaged using 3D-TRICKS and 3D-ELLIP sequentially in 14 patients. Temporal resolution was 12 sec for 3D-ELLIP and 6 sec for 3D-TRICKS. The signal-to-noise ratio (S/N) of the common carotid artery was measured, and the quality of MIP images was then scored in terms of venous overlap and blurring of vessel contours. No significant difference in mean S/N was seen between the two methods. Significant venous overlap was not seen in any of the patients examined. Moderate blurring of vessel contours was noted on 3D-TRICKS in five patients and on 3D-ELLIP in four patients. Blurring in the slice-encoding direction was slightly more pronounced in 3D-TRICKS. However, qualitative analysis scores showed no significant differences. When the spatial resolution of the two methods was identical, the performance of 3D-TRICKS was found to be comparable in static visualization of the carotid arteries with 3D-ELLIP, although blurring in the slice-encoding direction was slightly more pronounced in 3D-TRICKS. 3D-TRICKS is a more robust technique than 3D-ELLIP, because 3D-ELLIP requires operator-dependent fluoroscopic triggering. Furthermore, 3D-TRICKS can achieve higher temporal resolution. For the spatial resolution employed in this study, 3D-TRICKS may be the method of choice. (author)

  5. MR angiography after coiling of intracranial aneurysms

    NARCIS (Netherlands)

    Schaafsma, J.D.

    2012-01-01

    Introduction Endovascular occlusion with detachable coils has become an alternative treatment to neurosurgical clipping of intracranial aneurysms over the last two decades. Its minimal invasiveness is the most important advantage of this treatment compared to clipping. The disadvantage of occlusion

  6. MR angiography with a matched filter

    International Nuclear Information System (INIS)

    De Castro, J.B.; Riederer, S.J.; Lee, J.N.

    1987-01-01

    The technique of matched filtering was applied to a series of cine MR images. The filter was devised to yield a subtraction angiographic image in which direct current components present in the cine series are removed and the signal-to-noise ratio (S/N) of the vascular structures is optimized. The S/N of a matched filter was compared with that of a simple subtraction, in which an image with high flow is subtracted from one with low flow. Experimentally, a range of results from minimal improvement to significant (60%) improvement in S/N was seen in the comparisons of matched filtered subtraction with simple subtraction

  7. Hyperpolarized H2O MR angiography

    DEFF Research Database (Denmark)

    Ardenkjær-Larsen, Jan Henrik; Laustsen, Christoffer; Bowen, Sean

    2014-01-01

    polarization followed by dissolution in D2O. A water 1H signal enhancement of 77 times compared with 4.7 Tesla was obtained. This corresponds to a polarization of 3.5% for the 3.9 mol/L 1H in D2O . Moreover, a T1 in excess of 20 s was achieved. The use of hyperpolarized water as a contrast agent presents a new...

  8. Catheter Angiography

    Medline Plus

    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 ...

  9. Feasibility and Diagnostic Accuracy of Whole Heart Coronary MR Angiography Using Free-Breathing 3D Balanced Turbo-Field-Echo with SENSE and the Half-Fourier Acquisition Technique

    International Nuclear Information System (INIS)

    Kim, Young Jin; Seo, Jae Seung; Choi, Byoung Wook; Choe, Kyu Ok; Jang, Yang Soo; Ko, Young Guk

    2006-01-01

    We wanted to assess the feasibility and diagnostic accuracy of whole heart coronary magnetic resonance angiography (MRA) with using 3D balanced turbo-field-echo (b-TFE) with SENSE and the half-Fourier acquisition technique for identifying stenoses of the coronary artery. Twenty-one patients who underwent both whole heart coronary MRA examinations and conventional catheter coronary angiography examinations were enrolled in the study. The whole heart coronary MRA images were acquired using a navigator gated 3D b-TFE sequence with SENSE and the half-Fourier acquisition technique to reduce the acquisition time. The imaging slab covered the whole heart (80 contiguous slices with a reconstructed slice thickness of 1.5 mm) along the transverse axis. The quality of the images was evaluated by using a 5-point scale (0 - uninterpretable, 1 - poor, 2 - fair, 3 - good, 4 - excellent). Ten coronary segments of the heart were evaluated in each case; the left main coronary artery (LM), and the proximal, middle and distal segments of the left anterior descending (LAD), the left circumflex (LCX) and the right coronary artery (RCA). The diagnostic accuracy of whole heart coronary MRA for detecting significant coronary artery stenosis was determined on the segment-bysegment basis, and it was compared with the results obtained by conventional catheter angiography, which is the gold standard. The mean image quality was 3.7 in the LM, 3.2 in the LAD, 2.5 in the LCX, and 3.3 in the RCA, respectively (the overall image quality was 3.0 ± 0.1). 168 (84%) of the 201 segments had an acceptable image quality (≥ grade 2). The sensitivity, specificity, accuracy, negative predictive value and positive predictive value of the whole heart coronary MRA images for detecting significant stenosis were 81.3%, 92.1%, 91.1%, 97.9%, and 52.0%, respectively. The mean coronary MRA acquisition time was 9 min 22 sec (± 125 sec). Whole heart coronary MRA is a feasible technique, and it has good potential to

  10. 0.125 mm(3) spatial resolution steady-state MR angiography of the thighs with a blood pool contrast agent using the quadrature body coil only at 1.5 Tesla.

    Science.gov (United States)

    Boschewitz, Jack M; Hadizadeh, Dariusch R; Kukuk, Guido M; Meyer, Carsten; Wilhelm, Kai; Koscielny, Arne; Verrel, Frauke; Gieseke, Jürgen; Schild, Hans H; Willinek, Winfried A

    2014-10-01

    To implement and evaluate high spatial resolution three-dimensional MR contrast-enhanced angiography (3D-CEMRA) of the thighs using a blood pool contrast agent (BPCA) using the quadrature body coil only in patients with peripheral arterial occlusive disease (PAOD) in cases receiver coils cannot be used at 1.5 Tesla (T). Nineteen patients (mean age: 68.7 ± 11.2 years; range, 38-83 years) with known PAOD (Fontaine stages; III: 16, IV: 3) prospectively underwent 3D-CEMRA at 1.5T with a noninterpolated voxel size of 0.49 × 0.49 × 0.48 mm(3) . Digital subtraction angiography (DSA) was available for comparison in all patients. Two readers independently evaluated movement artifacts, overall image quality of 3D-CEMRA, and grade of stenosis as compared to DSA. SNR and CNR levels were quantified. The 3D-CEMRA was successfully completed in all patients. Patient movement artifacts that affected stenosis grading occurred in 3/38 thighs. Overall image quality was rated excellent in 15/38, good in 12/38, and diagnostic in 8/38 thighs. Stenosis grading matched with that in DSA in 35/38 thighs. High SNR and CNR were measured in all vessels. The 0.125 mm(3) spatial resolution 3D-CEMRA of the thighs with a BPCA is feasible using a quadrature body coil exclusively with excellent image quality despite long acquisition times. J. Magn. Reson. Imaging 2014;40:996-1001. © 2014 Wiley Periodicals, Inc. © 2014 Wiley Periodicals, Inc.

  11. 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 ...

  12. Detection of rotator cuff lesions with indirect MR angiography

    International Nuclear Information System (INIS)

    Rudolph, J.; Lorenz, M.; Schroeder, R.; Felix, R.

    2000-01-01

    Purpose: To determine the value of indirect MR arthrography in lesions of the rotator cuff, prospectively versus arthroscopy. Methods: 63 patients with suspected shoulder pathology were examined: Oblique-coronary and axial T 1 w sequences, axial FLASH-2 D sequences, furthermore oblique-coronary T 2 - and PD-weighted sequences were taken. After intravenous administration of 0.1 mmol Gd-DTPA/kilogram body weight and active motion of the shoulder T 1 w sequences were repeated. Signal intensities (SI) inside the tendon were quantitatively measured by the ROI technique (region-of-interest) and the percentual contrast-enhancement CE was calculated. In 32 patients the results were confirmed by surgical follow-up. Results: The mean SI measured in the supraspinous tendon were higher in lesions (degeneration, impingement, partial and total rupture), before as well as after contrast medium, compared to intact findings (p [de

  13. Expanding role of MR angiography in clinical practice

    International Nuclear Information System (INIS)

    Prince, M.R.; Meaney, J.F.M.

    2006-01-01

    MRA has higher accuracy, less operator dependence, a larger field-of-view, three-dimensionality and superior contrast resolution than ultrasonography. Additionally, MRA offers a safer alternative to the patient than CTA as neither ionizing radiation nor iodinated contrast agents are used. Contrast-enhanced MRA with extra cellular contrast agents is fast and flow-independent, offers substantially higher spatial and temporal resolution compared to non-contrast techniques and has become the standard of practice. The highly accurate but static anatomical road-map thus generated can be supplemented with time-resolved MRA and blood flow measurement techniques for a more comprehensive assessment of systemic vascular disease. In the context of burgeoning technological advances with rapid translation into clinical MRA practice, this review explores the current position of MRA and the potential role for the new and exciting blood-pool contrast agents for diagnosing and characterizing vascular disease. Blood-pool agents offer the potential to take MRA to the next level by combining first-pass arterial phase imaging with steady state high-resolution images that exploit the persistent high intravascular enhancement generated by blood-pool agents and which is significantly greater than with extra cellular agents. Additional benefits derive from the ability to characterize plaque and to detect internal bleeding. (orig.)

  14. 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

  15. Intracranial cystic lesions; Intrakranielle zystische Laesionen

    Energy Technology Data Exchange (ETDEWEB)

    Ahlhelm, F.; Goetschi, S. [Kantonsspital Baden AG, Abteilung fuer Neuroradiologie, Baden (Switzerland); Shariat, K. [Kantonsspital Winterthur, Klinik fuer Neurochirurgie, Winterthur (Switzerland); Ulmer, S. [Universitaetsklinikum Schleswig-Holstein, Klinik fuer Radiologie und Neuroradiologie, Kiel (Germany)

    2018-02-15

    . zerebrale Abszedierungen, die Zystizerkose oder Residuen nach konnataler Zytomegalievirusinfektion. Intrazerebrale zystische Defekte lassen sich auch bei entzuendlichen Erkrankungen des Zentralnervensystems wie der Multiplen Sklerose, aber auch bei Mitochondropathien, bei Leukodystrophien, nach Elektrolytentgleisungen als Residuen einer Myelinolyse oder nach Hirninfarkten z. B. bei alten lakunaeren Infarkten beobachten. Daneben koennen auch andere Defektareale zystisch imponieren, wie z. B. bei zystischen Enzephalomalazien nach einem Schaedel-Hirn-Trauma. Neben den radiologischen Befunden der Zysten in der Magnetresonanztomographie (MRT) bzw. in der Computertomographie (CT) helfen die Lokalisation, das Patientenalter, die Anamnese und die Labordiagnostik bei der Differenzialdiagnose. Neben der morphologischen Beurteilung koennen Advanced-MRT-Techniken wie die Diffusionsbildgebung beim Epidermoid oder der Einsatz der MR-Spektroskopie wertvolle Zusatzinformationen fuer die Differenzialdiagnose liefern. Intrakranielle Zysten koennen unterteilt werden in intra- und periventrikulaere Zysten, intraaxiale Zysten sowie Zysten in den externen Liquorraeumen. Assoziierte Tumornodularitaeten und das Kontrastmittelverhalten der Zystenwand und/oder assoziierter Weichteilanteile sowie die Reaktion des angrenzenden Parenchyms helfen bei der Diagnosefindung und Bewertung. (orig.)

  16. 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)

  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. In Vivo Validation of a Blood Vector Velocity Estimator with MR Angiography

    DEFF Research Database (Denmark)

    Hansen, Kristoffer Lindskov; Udesen, Jesper; Thomsen, Carsten

    2009-01-01

    Conventional Doppler methods for blood velocity estimation only estimate the velocity component along the ultrasound beam direction. This implies that a Doppler angle under examination close to 90° results in unreliable information about the true blood direction and blood velocity. The novel method...... indicate that reliable vector velocity estimates can be obtained in vivo using the presented angle-independent 2-D vector velocity method. The TO method can be a useful alternative to conventional Doppler systems by avoiding the angle artifact, thus giving quantitative velocity information....

  19. High spatial resolution whole-body MR angiography featuring parallel imaging: initial experience

    International Nuclear Information System (INIS)

    Quick, H.H.; Vogt, F.M.; Madewald, S.; Herborn, C.U.; Bosk, S.; Goehde, S.; Debatin, J.F.; Ladd, M.E.

    2004-01-01

    Materials and methods: whole-body multi-station MRA was performed with a rolling table platform (AngioSURF) on 5 volunteers in two imaging series: 1) standard imaging protocol, 2) modified high-resolution protocol employing PAT using the generalized autocalibrating partially parallel acquisitions (GRAPPA) algorithm with an acceleration factor of 3. For an intra-individual comparison of the two MR examinations, the arterial vasculature was divided into 30 segments. Signal-to-noise ratios (SNR) and contrast-to-noise ratios (CNR) were calculated for all 30 arterial segments of each subject. Vessel segment depiction was qualitatively assessed applying a 5-point scale to each of the segments. Image reconstruction times were recorded for the standard as well as the PAT protocol. Results: compared to the standard protocol, PAT allowed for increased spatial resolution through a 3-fold reduction in mean voxel size for each of the 5 stations. Mean SNR and CNR values over all specified vessel segments decreased by a factor of 1.58 and 1.56, respectively. Despite the reduced SNR and CNR, the depiction of all specified vessel segments increased in PAT images, reflecting the increased spatial resolution. Qualitative comparison of standard and PAT images showed an increase in vessel segment conspicuity with more detailed depiction of intramuscular arterial branches in all volunteers. The time for image data reconstruction of all 5 stations was significantly increased from about 10 minutes to 40 minutes when using the PAT acquisition. (orig.) [de

  20. In-vivo evaluation of three ultrasound vector velocity techniques with MR angiography

    DEFF Research Database (Denmark)

    Hansen, Kristoffer Lindskov; Udesen, Jesper; Oddershede, Niels

    2008-01-01

    In conventional Doppler ultrasound (US) the blood velocity is only estimated along the US beam direction. The estimate is angle corrected assuming laminar flow parallel to the vessel boundaries. As the now in the vascular system never is purely laminar, the velocities estimated with conventional...... additionally constructed and mean differences for the three comparisons were: DB/MRA = 0.17 ml; STA/MRA = 0.07 ml; TO/MRA = 0.24 ml. The three US vector velocity techniques yield quantitative insight in to flow dynamics and can potentially give the clinician a powerful tool in cardiovascular disease assessment....

  1. Gadopentate dimeglumine enhanced MR angiography (MRA) for staging AAA: a correlation with DSA and CT

    International Nuclear Information System (INIS)

    Arlart, I.P.; Gerlach, A.; Kolb, M.; Erpenbach, S.; Wuerstlin, S.

    1997-01-01

    Purpose: To evaluate a contrast-enhanced (CE) MRA sequence for staging AAA. Methods: In 24 patients (male=20, female=4, age=44-81 y) with known AAA the abdominal aorta and its branches including the iliac arteries were imaged, using a 3D GRE-FISP sequence (1.5 T, T R /T E /FA=25/6/35, slab=100-140 mm, 32 part., FOV=440-450 mm, matrix=256x256) during an i.v. infusion of 40 ml of gadopentate dimeglumine. In addition, representative axial single slices (2D breathhold FLASH-sequence: T R /T E /FA=82/5/30) were acquired following contrast application. MR-results were correlated with i.a. DSA and CT studies. Results: With CE-MRA, AAA (n=24) and iliac aneurysms (n=17) could be evaluated in all cases (sens.=100%, spec.=100%) including luminal patency and mural thrombus. 50/54 renal arteries could be identified, 4/6 accessory renal arteries (sens=66,6%, spec.=100%), 8/9 renal artery stenoses>50% (sens.=88.8%, spec.=89.3%), 1/1 renal artery occlusion and 7/8 iliac artery stenoses>50% (sens.=87.5%, spec.=97.5%) were depicted correctly. Proximal portion of sup. mes. art. could be detected and evaluated in 21/24 cases. Quantitative determination of therapeutically relevant vascular paramters using MRA was comparable to DSA and CT. (orig./AJ) [de

  2. Coregistration of three dimensional DSA and MR angiography in neuronavigation for neurosurgery

    International Nuclear Information System (INIS)

    Tang Weijun; Jin Yi; Li Ke; Feng Xiaoyuan; Hong Yong

    2007-01-01

    Objective: To assess the accuracy of neuronavigation of 3D DSA and to evaluate the feasibility of 3D DSA neuronavigational neurosurgery through the coregistration of 3D DSA and MRI(A). Methods: A Peg-Board Phantom was used in our study. The phantom consisted of 32 rods which were used for target localization; the height and the location of the rods were in normal distribution. For 3D DSA (Infinix NS/VC, Toshiba), the raw data was reconstructed to 3D images on the DSA workstation, and transferred to a online PC workstation where it was converted to standard 2D DICOM image data using WFU DICOM T oolkit software. For MRI (A), the phantom was scanned with FSPGR sequence on the MRI scanner (GE Signa VH/i 3.0 T), and the DICOM images were also transferred to the online PC workstation. Using the software 3D Slicer registration was performed on the PC workstation by using the location and shape of the rods in the phantom. The localization error of the rods was measured in image space as the Euclidean distance between targets defined in image space and those detected in the physical space. Paired t test was used to evaluate the difference between the accuracy of neuronaviagtion of 3D DSA and that of MRI(A). Results: Through the coregistration of the rods in the phantom from different modality, all the images were better coregistrated. The mean localization error was (0.38 ± 0.24)mm (3D DSA) and (0.31 ± 0.12)mm[MRI(A)]. There was no significant statistical difference between the accuracy of neuronavigation of 3D DSA and MRI(A) (t=-0.601, P=0.55). Conclusion: 3D DSA images can be used in the neuronavigation system through the coregistration of 3D DSA and MRI(A). (authors)

  3. Intraindividual assessment of the thoracic aorta using contrast and non-contrast-enhanced MR angiography

    International Nuclear Information System (INIS)

    Tengg-Kobligk, Hendrik von; Gruenberg, K.M.; Giesel, F.L.; Ley-Zaporozhan, J.; Ley, S.; Henninger, V.; Kauczor, H.U.; Radiologische Universitaetsklinik Heidelberg; Boeckler, D.; Krummenauer, F.

    2009-01-01

    To avoid intravenous contrast media application, new MRA sequences using inherent blood contrast are available. The clinical use of these non-contrast-enhanced MRA (non-CE-MRA) sequences is still limited for the aorta. Thus, the goal was to compare a standard CE-MRA with a non-CE-MRA for the thoracic aorta. Ethics committee approval and informed consent were obtained. CE-MRA and non-CE-MRA (1.5T) were performed in the same 50 healthy volunteers (mean age: 48). CE-MRA: GRE-Turbo-Flash-3D (1.2 x 1.2 x 1.6 mm 3 ), 0.15 mmol Gd/kg, TA 22 ± 2sec. Non-CE-MRA: Respiratory-and cardiac-gated, T 2-prepared 3D-trueFISP (1.2 x 1.2 x 1.3 mm 3 ), TA 14 ± 5 min. Assessment included (3 readers, consensus): image quality (sharpness of vessel wall, signal homogeneity, artifacts) at the ascending aorta, arch, descending aorta and supra-aortic vessels. The image quality in the ascending aorta was rated 'excellent' in 78 %, 'moderate' in 22 %, 'poor' in 0 % for non-CE-MRA versus 22 %, 50 %, and 28 % for CE-MRA (Cohen's kappa = 29 %, McNemar p < 0.001). In a comparison of non-CE-MRA versus CE-MRA, the aortic arch and descending aorta showed no significant difference (kappa = 58 %/p = 0.250 and kappa = 100 %/p 1.000, respectively). Supra-aortic vessels were rated 'excellent' 45 %/49 %, 'moderate' 30 %/49 % and 'poor' 13 %/2 %, 12 % of supra-aortic vessels were visualized < 1 cm at non-CE-MRA. (orig.)

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

    DEFF Research Database (Denmark)

    Lipsø, Hans Kasper Wigh; Hansen, Esben Søvsø Szocska; Tougaard, Rasmus Stilling

    2016-01-01

    at 3 Tesla (T). Approximately 15 mL of hyperpolar-ized water was injected in the renal artery by hand over 4–5 s.Results: A liquid state polarization of 5.3 6 0.9% of 3.8 M pro-tons in 15 mL of deuterium oxide was achieved with a T1of24 6 1 s. This allowed injection through an arterial catheterinto...

  5. 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.

  6. 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

  7. MR inflow angiography for the evaluation of dural sinus patency

    International Nuclear Information System (INIS)

    Poncelet, B.; Baleriaux, D.; Grand, C.; Van Dijk, P.; De Graaf, R.; Segebarth, C.

    1990-01-01

    This paper assesses dural sinus patency with two-dimensional inflow MR angiography. Twelve patients with potential dural sinus (superior sagittal and transverse sinus) involvement related to tumors of the falx or the convexity (meningiomas, metastasis) were examined with digital subtraction angiography (DSA), Mr imaging (1.5-T Gyroscan system), including T1-weighted (pre- and post-agadolinium) and T2-weighted spin-echo imaging, and MR angiography. For the MR angiographic study, a gradient-echo fast field echo sequence with flow compensation was used. Thin (2-mm), contiguous coronal or transverse sections were acquired sequentially. Three-dimensional reconstruction with MIP processing was then performed. CT, DSA, and MR imaging were performed for presurgical evaluation. Surgical confirmation of sinus patency was obtained for all patients

  8. 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.

  9. Angio-RM das artérias carótidas e vertebrais: análise de diferentes técnicas de volume e diluição de contraste em aparelho de 1,0 t e gradiente de 15 mt/m Contrast-enhanced MR angiography of the carotid and vertebral arteries: analysis of different contrast volumes and dilution techniques at 1.0 T with 15 mT/m gradient.

    Directory of Open Access Journals (Sweden)

    Luiz Guilherme C. Hartmann

    2001-08-01

    Full Text Available OBJETIVO: Avaliar as artérias cervicais (carótidas e vertebrais por meio da angio-RM, utilizando-se diferentes dosagens e diluições de contraste paramagnético. MATERIAIS E MÉTODOS: Estudo prospectivo em 15 pacientes, com análise de 30 artérias carótidas comuns, 30 artérias carótidas internas, 30 artérias carótidas externas e 30 artérias vertebrais, utilizando-se diferentes volumes e dosagens de contraste paramagnético: grupo I - dose única (14 ml de Gd-DTPA; grupo II -dose dupla (28 ml de Gd-DTPA; grupo III - dose única e diluída a 50%. A injeção de contraste foi realizada com a utilização de bomba injetora e com velocidades de injeção de 2 ml/s (grupo I e 3 ml/s (grupos II e III. Os segmentos arteriais foram analisados por três examinadores em consenso de forma subjetiva, avaliando-se o grau de visibilidade, intensidade de contrastação e definição de seus contornos. RESULTADOS: Em todos os itens analisados os pacientes do grupo II apresentaram melhor resultado (visibilização total, boa contrastação dos vasos e contornos bem definidos. No grupo I houve boa visibilização das artérias carótidas e vertebrais, porém a intensidade de contraste e a definição dos contornos apresentaram variabilidade qualitativa. O grupo III apresentou os piores resultados, com dificuldade de visibilização, intensidade de contrastação baixa e contornos mal definidos. CONCLUSÃO: Entre os grupos analisados, a técnica utilizando dose dupla de gadolínio é a que permite melhor avaliação das artérias cervicais. A utilização de contraste diluído prejudica a avaliação dos vasos do pescoço.PURPOSE: To evaluate the carotid and vertebral arteries by magnetic resonance angiography, using different contrast volumes and dilution techniques. SUBJECTS AND METHODS: Prospective study of 15 patients, which included the evaluation of 30 common carotid arteries, 30 internal carotid arteries, 30 external carotid arteries and 30

  10. 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)

  11. 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)

  12. 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

  13. Contrast-Enhanced MR Angiography (CEMRA) in Peripheral Arterial Occlusive Disease (PAOD): conventional moving table technique versus hybrid technique; Kontrastverstaerkte MR-Angiographie (CEMRA) bei peripherer AVK (pAVK): konventionelle Tischverschiebetechnik versus Hybrid-Technik

    Energy Technology Data Exchange (ETDEWEB)

    Kalle, T. von; Gerlach, A.; Hatopp, A.; Klinger, S.; Prodehl, P.; Arlat, I.P. [Katharinenhospital, Stuttgart (Germany). Radiologisches Inst.

    2004-01-01

    Patients and Methods: 80 patients (males n = 60, females n = 20, median age = 70 years, diabetics n = 27) with PAOD were examined with a 1,5T system (40 mT/m) using a dedicated phased array peripheral vascular coil. Protocol A consisted of a single injection of Gd-BOPTA with consecutive craniocaudal image acquisition and protocol B of two injections, with the first injection of Gd-BOPTA followed by image acquisition of the popliteocrural and pedal segments and the second injection followed by acquiring the aortoiliac and femoral segments (hybrid technique). The evaluation of the arterial system was directed to the iliac, femoral, popliteocrural and pedal arteries. Results: The visualization of the entire aortopedal vascular system was of diagnostically good or satisfactory quality in 16 of 40 patients using protocol A and in 29 of 40 patients using protocol B (iliac 40 vs. 37, femoral 40 vs. 40, popliteocrural 35 vs. 37, pedal 16 vs. 29); without the pedal station the number increased to 35 of 40 patients for both protocols. The reason of diagnostic limitations was an arteriovenous overlap in 24 of 80 cases, with 19 of 40 cases for protocol A and 5 of 40 for protocol B, located exclusively in the cruropedal region. Conclusion: Moving table hybrid CEMRA is superior to conventional technique in craniocaudal direction by producing less venous overlap of arteries and is especially more suitable for the diagnostic evaluation of the cruropedal region. (orig.) [German] Patienten und Methodik: Untersucht wurden 80 Patienten (maennl. n = 60, weibl. n = 20, mittl. Alter 70 J., Diabetiker n = 27) mit pAVK an einem 1,5-Tesla-Geraet (40 mT/m) mit dedizierter Phased-Array-Oberflaechen-Gefaessspule. Protokoll A beinhaltete eine Kontrastmittel-Injektion (Gd-BOPTA) mit konsekutiver kraniokaudaler Bildakquisition. In Protokoll B erfolgte die Akquisition zunaechst der Unterschenkel- und Fussetage mittels einer ersten, anschliessend der Abdomen-Becken- und Oberschenkeletage mittels einerzzweiten KM-Injektion (Hybrid-Technik). Bewertet wurden die aorto-iliakalen, femoralen, popliteo-kruralen und pedalen Arterien. Ergebnisse: Mit Protokoll A waren 16/40, mit Protokoll B 29/40 der gesamten aorto-pedalen Gefaessstrecken diagnostisch gut oder zufriedenstellend beurteilbar (iliakal 40 vs. 37, femoral 40 vs. 40, popliteo-krural 35 vs. 37, pedal 16 vs. 29); ohne Fussetage erhoehte sich die Zahl auf 35/40 vs. 35/40. Ursache einer diagnostischen Einschraenkung war in 24 der 80 Faelle die Ueberlagerung der Arterien durch kontrastierte Venen (Protokoll A vs. B = 19/40 vw. 5/40), diese betraf ausschliesslich die kruro-pedale Region. Schlussfolgerung: Die CEMRA in Hybridtechnik ist der konventionellen kraniokaudalen Tischverschiebe-Technik hinsichtlich stoerender Ueberlagerung durch kontrastierte Venen deutlich ueberlegen und eignet sich besser vor allem fuer die diagnostische Darstellung der kruro-pedalen Region. (orig.)

  14. Combined T1-based perfusion MRI and MR angiography in kidney: First experience in normals and pathology

    Energy Technology Data Exchange (ETDEWEB)

    Dujardin, Martine [Department of Radiology/BEFY, UZ Brussel, Vrije Universiteit Brussel, Laarbeeklaan 101, 1090 Brussels (Belgium)], E-mail: martine.dujardin@gmail.com; Luypaert, Rob [Department of Radiology/BEFY, UZ Brussel, Vrije Universiteit Brussel, Laarbeeklaan 101, 1090 Brussels (Belgium)], E-mail: rluypaer@vub.ac.be; Vandenbroucke, F. [Department of Radiology/BEFY, UZ Brussel, Vrije Universiteit Brussel, Laarbeeklaan 101, 1090 Brussels (Belgium)], E-mail: frederik.vandenbroucke@uzbrussel.be; Van der Niepen, Patricia [Department of Nephrology, UZ Brussel, Laarbeeklaan 101, 1090 Brussels (Belgium)], E-mail: hemovnnp@az.vub.ac.be; Sourbron, Steven [Institute of Clinical Radiology, Ludwig-Maximilian-University Munich, Marchioninistrasse 15, 81377 Munchen (Germany)], E-mail: Steven.Sourbron@med.uni-muenchen.de; Verbeelen, Dierik [Department of Nephrology, UZ Brussel, Laarbeeklaan 101, 1090 Brussels (Belgium)], E-mail: dierik.verbeelen@uzbrussel.be; Stadnik, T. [Department of Radiology/BEFY, UZ Brussel, Vrije Universiteit Brussel, Laarbeeklaan 101, 1090 Brussels (Belgium)], E-mail: tadeusz.stadnik@uzbrussel.be; Mey, Johan de [Department of Radiology/BEFY, UZ Brussel, Vrije Universiteit Brussel, Laarbeeklaan 101, 1090 Brussels (Belgium)], E-mail: johan.demey@uzbrussel.be

    2009-03-15

    Objectives: To investigate the feasibility of implementing quantitative T1-perfusion in the routine MRA-protocol and to obtain a first experience in normals and pathology. Materials and methods: For perfusion imaging, IR-prepared FLASH (one 4 mm slice at mid-renal level, TR 4.4 ms, TE 2.2 ms, TI 180 ms, FA 50 deg., matrix 128 x 256, bandwidth per pixel 300, 400 dynamics, temporal resolution 0.3 s, total measurement time 2 min) was applied during the injection of 10 ml of standard 0.5 mmol/ml Gadolinium-DTPA solution at 2 ml/s, followed by 3DCE-MRA with bolus tracking (TR 5.4, TE 1.4, FA 40 deg., matrix 192 x 512, NSA 1, slice thickness 1.5 mm), using a second dose of 0.1 mmol Gadolinium-DTPA per kg body weight with a maximum of 20 ml. The T1-weighted signals (perfusion data) were converted to tissue tracer concentrations and deconvolved with an inflow corrected AIF; blood flow, distribution volume, mean transit time and blood flow heterogeneity were derived. Results: MRA quality was uncompromised by the first bolus administered for perfusion purposes. In the normals, average cortical RBF, RVD and MTT were 1.2 ml/min/ml (S.D. 0.3 ml/min/ml), 0.4 ml/ml (S.D. 0.1 ml/ml) and 21 s (S.D. 4 s). These RBF values are lower than those found in the literature, probably due to residual AIF inflow effects. The sensitivity of the technique was sufficient to demonstrate altered perfusion in the examples of pathology. Conclusion: Combined quantitative T1-perfusion and MRA have a potential for noninvasive renovascular screening and may provide an anatomical and physiological evaluation of renal status.

  15. All-phase MR angiography using independent component analysis of dynamic contrast enhanced MRI time series. φ-MRA

    International Nuclear Information System (INIS)

    Suzuki, Kiyotaka; Matsuzawa, Hitoshi; Watanabe, Masaki; Nakada, Tsutomu; Nakayama, Naoki; Kwee, I.L.

    2003-01-01

    Dynamic contrast enhanced magnetic resonance imaging (dynamic MRI) represents a MRI version of non-diffusible tracer methods, the main clinical use of which is the physiological construction of what is conventionally referred to as perfusion images. The raw data utilized for constructing MRI perfusion images are time series of pixel signal alterations associated with the passage of a gadolinium containing contrast agent. Such time series are highly compatible with independent component analysis (ICA), a novel statistical signal processing technique capable of effectively separating a single mixture of multiple signals into their original independent source signals (blind separation). Accordingly, we applied ICA to dynamic MRI time series. The technique was found to be powerful, allowing for hitherto unobtainable assessment of regional cerebral hemodynamics in vivo. (author)

  16. Contrast-Enhanced MR Angiography (CEMRA) in Peripheral Arterial Occlusive Disease (PAOD): conventional moving table technique versus hybrid technique

    International Nuclear Information System (INIS)

    Kalle, T. von; Gerlach, A.; Hatopp, A.; Klinger, S.; Prodehl, P.; Arlat, I.P.

    2004-01-01

    Patients and Methods: 80 patients (males n = 60, females n = 20, median age = 70 years, diabetics n = 27) with PAOD were examined with a 1,5T system (40 mT/m) using a dedicated phased array peripheral vascular coil. Protocol A consisted of a single injection of Gd-BOPTA with consecutive craniocaudal image acquisition and protocol B of two injections, with the first injection of Gd-BOPTA followed by image acquisition of the popliteocrural and pedal segments and the second injection followed by acquiring the aortoiliac and femoral segments (hybrid technique). The evaluation of the arterial system was directed to the iliac, femoral, popliteocrural and pedal arteries. Results: The visualization of the entire aortopedal vascular system was of diagnostically good or satisfactory quality in 16 of 40 patients using protocol A and in 29 of 40 patients using protocol B (iliac 40 vs. 37, femoral 40 vs. 40, popliteocrural 35 vs. 37, pedal 16 vs. 29); without the pedal station the number increased to 35 of 40 patients for both protocols. The reason of diagnostic limitations was an arteriovenous overlap in 24 of 80 cases, with 19 of 40 cases for protocol A and 5 of 40 for protocol B, located exclusively in the cruropedal region. Conclusion: Moving table hybrid CEMRA is superior to conventional technique in craniocaudal direction by producing less venous overlap of arteries and is especially more suitable for the diagnostic evaluation of the cruropedal region. (orig.) [de

  17. Determination of the optimal speed of rotational display through an 180 degree arc in rotatostereoradiography and MR angiography

    International Nuclear Information System (INIS)

    Ottomo, M.; Takekawa, S.D.; Sugawara, K.; Nakamura, T.; Fujimoto, M.; Nakanishi, T.

    1990-01-01

    Rotatostereoradiographic (RSRG) images are displayed in an oscillating, rotational manner. While reviewing these rotating images, the radiologist may become psychologically irritated by the rotation. A rapidly rotating display of linear subjects gives one three-dimensional depth information. This three-dimensional sense is lost if the rotation speed is too slow. The authors of this paper determined the slowest possible rotating display speed that allows perception of three-dimensional depth information minimizing psychological irritation. In the RSRG device (Shimadzu ROTATO-360), an x-ray tube coupled with an image intensifier rotates through a 180 degrees arc in 1.8 or 2.25 seconds. Both rotation times could be doubled. The images were displayed at four different speeds, covering the 180 degrees arc in 1.8, 2.25, 3.6, and 4.5 seconds

  18. A new experimental carotid siphon aneurysm model in canine based on the MR angiography and rapid prototyping technology

    International Nuclear Information System (INIS)

    Xie Jian; Li Minghua; Tan Huaqiao; Zhu Yueqi; Hu Dingjun; Qiao Ruihua; Fan Chunhua

    2009-01-01

    Objective: The aim of the experiment is to make an intracranial aneurysm model in canine. Methods: A digital tube was made based on raw magnetic resonance images of the human intracranial carotid artery. Then 6 tubes were made in the 3D rapid prototyping machine and coated with silicone. Finally we isolated the common carotid arteries of 6 canines and made them go through the tubes and anastomosed them end-to-side to get the aneurysm model. Six stents were implanted after one week. Results: Six aneurysm models were successfully made in canines. The parent artery had similar geometry of the human carotid siphon. All the aneurysms and parent arteries were patent in one week's follow-up. One canine died of excessive anesthesia after stenting. Two vascular models kept patent in one month without stenosis. The other 3 had some stenosis on the bends of the vessel. Conclusions: The aneurysm model in the experiment has high flexibility and reliability. The model provides an effective tool for research and testing neurovascular devices. It's also a useful device to train the neuroradiologists and interventional physicians. (authors)

  19. Prediction of infarction and reperfusion in stroke by flow- and volume-weighted collateral signal in MR angiography.

    Science.gov (United States)

    Ernst, M; Forkert, N D; Brehmer, L; Thomalla, G; Siemonsen, S; Fiehler, J; Kemmling, A

    2015-02-01

    In proximal anterior circulation occlusive strokes, collateral flow is essential for good outcome. Collateralized vessel intensity in TOF- and contrast-enhanced MRA is variable due to different acquisition methods. Our purpose was to quantify collateral supply by using flow-weighted signal in TOF-MRA and blood volume-weighted signal in contrast-enhanced MRA to determine each predictive contribution to tissue infarction and reperfusion. Consecutively (2009-2013), 44 stroke patients with acute proximal anterior circulation occlusion met the inclusion criteria with TOF- and contrast-enhanced MRA and penumbral imaging. Collateralized vessels in the ischemic hemisphere were assessed by TOF- and contrast-enhanced MRA using 2 methods: 1) visual 3-point collateral scoring, and 2) collateral signal quantification by an arterial atlas-based collateral index. Collateral measures were tested by receiver operating characteristic curve and logistic regression against 2 imaging end points of tissue-outcome: final infarct volume and percentage of penumbra saved. Visual collateral scores on contrast-enhanced MRA but not TOF were significantly higher in patients with good outcome. Visual collateral scoring on contrast-enhanced MRA was the best rater-based discriminator for final infarct volume 50% (area under the curve, 0.67; P = .04). Atlas-based collateral index of contrast-enhanced MRA was the overall best independent discriminator for final infarct volume of collateral index combining the signal of TOF- and contrast-enhanced MRA was the overall best discriminator for effective reperfusion (percentage of penumbra saved >50%; area under the curve, 0.89; P collateral assessment, TOF- and contrast-enhanced MRA both contain predictive signal information for penumbral reperfusion. This could improve risk stratification in further studies. © 2015 by American Journal of Neuroradiology.

  20. 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).

  1. 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)

  2. Comparison of contrast enhanced MR-angiography-MRI and digital subtraction angiography in the evaluation of pancreas and/or kidney transplantation patients : initial experience

    NARCIS (Netherlands)

    Boeve, WJ; Kok, T; Tegzess, Adam; van Son, WJ; Ploeg, RJ; Sluiter, WJ; Kamman, RL

    To evaluate whether combined contrast enhanced MRA and MRI (ce-MRA-MRI) has the potential to replace intra-arterial DSA (i.a.DSA) in patients with impaired graft function or suspected of vascular complications after pancreas and/or kidney transplantation. 7 patients after combined pancreas-kidney

  3. 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)

  4. 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 ...

  5. 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

  6. Preoperative examination of potential renal transplant donors: value of gadolinium-enhanced 3D-MR-angiography in comparison with DSA and urography

    International Nuclear Information System (INIS)

    Winterer, J.T.; Paul, G.; Einert, A.; Altehoefer, C.; Uhrmeister, P.; Laubenberger, J.

    2000-01-01

    Purpose: To assess a contrast-enhanced standardized MRA protocol for the presurgical evaluation of potential renal transplant donors. Methods: Twenty-three potential donors for renal transplantations were examined with gadolinium-enhanced, two-phase MR angiograms (1.5 T) and DSA/urography for the number of renal arteries, the presence of aberrant arterial and venous branches, renal artery stenoses and anatomy of the renal collecting system and ureters. The diagnostic value was assessed by evaluating different image processing modalities and interobserver variability. Results: Using maximum intensity projections (MIP) together with multiplanar reformatting (MPR), accessory arteries were detected with a sensitivity/specificity of 100%/98%. Depending on diagnostic experience, exclusive evaluation of MIP yielded a sensitivitiy/specificity of 67-100%/95-100%. Using MIP/MPR, venous depiction was good in 80%, with MIP solely in 30-40%. At least the proximal third of the ureter was visible in 67%. Conclusion: MPR/MIP evaluation of two-phase, contrast-enhanced MRA provides an excellent depiction of renal vessel anatomy for presurgical evaluation of renal transplant donors. Exclusive MIP assessment is less reliable and depends strongly on the examiner's experience. For sufficient visualization of the ureters, either additional measurements or low-dose diuretic injection have to be performed. (orig.) [de

  7. The clinical value of 3D dynamic contrast enhanced MR angiography on haemorrhage of esophageal and gastric varices compared with endoscopy

    International Nuclear Information System (INIS)

    Wu Zhou; Liang Biling; Li Yong; Zhong Jinglian; Ye Ruixin; Wang Dongye; Li Chuqiang; Yuan Yuhong

    2010-01-01

    Objective: To investigate the clinical value of three dimensional dynamic contrast enhanced MRA (3D DCE MRA) on esophageal and gastric varices compared with endoscopy. Methods: From April 2003 to June 2008, 153 patients with portal hypertension who underwent both 3D DCE MRA and endoscopy were reviewed retrospectively. All the patients were divided into bleeding group and non-bleeding group according to the clinical symptoms. The location and degree of the esophagogastric varices on 3D DCE MRA were assessed with postprocessing images, including subtraction, MIP and thin-slab masimum intensity projection (tin-MIP), and were compared with the results of endoscopy. The maximum, minimum and mean diameters of esophagogastric varices inside and outside of the wall were measured on the reformed images. The correlation between the findings of 3D DCE MRA and endoscopy were analyzed with Spearman rank correlation coefficient test. The rates of esophagogastric varices outside of the wall in bleeding and non-bleeding group were compared by means of Chi-square test. Results: In bleeding group, severe esophageal varices were documented in 59 patients, moderate in 6 patients, mild in 5 patients; in non-bleeding group, severe esophageal varices were documented in 32 patients, moderate in 4 patients, mild in 5 patients. Severe, moderate, and mild gastric varices were documented in 28, 34 and 16 in bleeding group, while they were 7, 12 and 9 in non-bleeding group. Esophageal and gastric varices can be wholly pressnted on MIP images after subtraction, while the esophagogastric varices inside and outside of the wall can be differentiated on thin-MIP images. The location and degree of esophagogastric varices on 3D DCE MRA were correlated with the findings of the endoscopy. The range of r was from 0.544 to 0.878 (P 2 =7.199, P<0.01). In 35 patients with severe gastric varices, 22 patients showed adventitial gastric varices in bleeding group (n=28) and 4 patients showed adventitial gastric varices in non-bleeding group (n=7). The ratio of adventitial gastric varices in bleeding group was not significantly different from that of non-bleeding group (P=0.340). Conclusions: 3D DCE MRA can display and differentiate the esophagogastric varices both inside and outside of the wall by three dimensional reconstruction. The esophagogastric varices both inside and outside of the wall by three dimensional reconstruction. The results of 3D DCE MRA and endoscopy have good correlation. It is of importance in evaluating the esophageal varices outside of the wall, because they may indicate decreased risk of haemorrhage in patients with severe degree of esophageal varices. (authors)

  8. Non-contrast-enhanced hepatic MR angiography: Do two-dimensional parallel imaging and short tau inversion recovery methods shorten acquisition time without image quality deterioration?

    Energy Technology Data Exchange (ETDEWEB)

    Shimada, Kotaro, E-mail: kotaro@kuhp.kyoto-u.ac.jp [Department of Diagnostic Imaging and Nuclear Medicine, Kyoto University, Graduate School of Medicine, 54 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507 (Japan); Isoda, Hiroyoshi, E-mail: sayuki@kuhp.kyoto-u.ac.jp [Department of Diagnostic Imaging and Nuclear Medicine, Kyoto University, Graduate School of Medicine, 54 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507 (Japan); Okada, Tomohisa, E-mail: tomokada@kuhp.kyoto-u.ac.jp [Department of Diagnostic Imaging and Nuclear Medicine, Kyoto University, Graduate School of Medicine, 54 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507 (Japan); Kamae, Toshikazu, E-mail: toshi13@kuhp.kyoto-u.ac.jp [Department of Diagnostic Imaging and Nuclear Medicine, Kyoto University, Graduate School of Medicine, 54 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507 (Japan); Arizono, Shigeki, E-mail: arizono@kuhp.kyoto-u.ac.jp [Department of Diagnostic Imaging and Nuclear Medicine, Kyoto University, Graduate School of Medicine, 54 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507 (Japan); Hirokawa, Yuusuke, E-mail: yuusuke@kuhp.kyoto-u.ac.jp [Department of Diagnostic Imaging and Nuclear Medicine, Kyoto University, Graduate School of Medicine, 54 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507 (Japan); Shibata, Toshiya, E-mail: ksj@kuhp.kyoto-u.ac.jp [Department of Diagnostic Imaging and Nuclear Medicine, Kyoto University, Graduate School of Medicine, 54 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507 (Japan); Togashi, Kaori, E-mail: ktogashi@kuhp.kyoto-u.ac.jp [Department of Diagnostic Imaging and Nuclear Medicine, Kyoto University, Graduate School of Medicine, 54 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507 (Japan)

    2011-01-15

    Objective: To study whether shortening the acquisition time for selective hepatic artery visualization is feasible without image quality deterioration by adopting two-dimensional (2D) parallel imaging (PI) and short tau inversion recovery (STIR) methods. Materials and methods: Twenty-four healthy volunteers were enrolled. 3D true steady-state free-precession imaging with a time spatial labeling inversion pulse was conducted using 1D or 2D-PI and fat suppression by chemical shift selective (CHESS) or STIR methods. Three groups of different scan conditions were assigned and compared: group A (1D-PI factor 2 and CHESS), group B (2D-PI factor 2 x 2 and CHESS), and group C (2D-PI factor 2 x 2 and STIR). The artery-to-liver contrast was quantified, and the quality of artery visualization and overall image quality were scored. Results: The mean scan time was 9.5 {+-} 1.0 min (mean {+-} standard deviation), 5.9 {+-} 0.8 min, and 5.8 {+-} 0.5 min in groups A, B, and C, respectively, and was significantly shorter in groups B and C than in group A (P < 0.01). The artery-to-liver contrast was significantly better in group C than in groups A and B (P < 0.01). The scores for artery visualization and overall image quality were worse in group B than in groups A and C. The differences were statistically significant (P < 0.05) regarding the arterial branches of segments 4 and 8. Between group A and group C, which had similar scores, there were no statistically significant differences. Conclusion: Shortening the acquisition time for selective hepatic artery visualization was feasible without deterioration of the image quality by the combination of 2D-PI and STIR methods. It will facilitate using non-contrast-enhanced MRA in clinical practice.

  9. Non-contrast-enhanced hepatic MR angiography: Do two-dimensional parallel imaging and short tau inversion recovery methods shorten acquisition time without image quality deterioration?

    International Nuclear Information System (INIS)

    Shimada, Kotaro; Isoda, Hiroyoshi; Okada, Tomohisa; Kamae, Toshikazu; Arizono, Shigeki; Hirokawa, Yuusuke; Shibata, Toshiya; Togashi, Kaori

    2011-01-01

    Objective: To study whether shortening the acquisition time for selective hepatic artery visualization is feasible without image quality deterioration by adopting two-dimensional (2D) parallel imaging (PI) and short tau inversion recovery (STIR) methods. Materials and methods: Twenty-four healthy volunteers were enrolled. 3D true steady-state free-precession imaging with a time spatial labeling inversion pulse was conducted using 1D or 2D-PI and fat suppression by chemical shift selective (CHESS) or STIR methods. Three groups of different scan conditions were assigned and compared: group A (1D-PI factor 2 and CHESS), group B (2D-PI factor 2 x 2 and CHESS), and group C (2D-PI factor 2 x 2 and STIR). The artery-to-liver contrast was quantified, and the quality of artery visualization and overall image quality were scored. Results: The mean scan time was 9.5 ± 1.0 min (mean ± standard deviation), 5.9 ± 0.8 min, and 5.8 ± 0.5 min in groups A, B, and C, respectively, and was significantly shorter in groups B and C than in group A (P < 0.01). The artery-to-liver contrast was significantly better in group C than in groups A and B (P < 0.01). The scores for artery visualization and overall image quality were worse in group B than in groups A and C. The differences were statistically significant (P < 0.05) regarding the arterial branches of segments 4 and 8. Between group A and group C, which had similar scores, there were no statistically significant differences. Conclusion: Shortening the acquisition time for selective hepatic artery visualization was feasible without deterioration of the image quality by the combination of 2D-PI and STIR methods. It will facilitate using non-contrast-enhanced MRA in clinical practice.

  10. A study of arteries of foot by flow sensitive dephasing prepared balanced steady-state free precession MR angiography in diabetes

    International Nuclear Information System (INIS)

    Zou Liqiu; Liu Xiaoyi; Liu Xin; Feng Fei; Qi Yulong; Liu Pengcheng

    2011-01-01

    Objective: To investigate balanced steady-state free precession with flow-sensitive dephasing magnetization preparation (FSD-bSSFP) in the assessment of arteries of foot in diabetic patients. Methods: The lower-extremity peripheral arteries of 43 diabetic patients were evaluated by FSD-bSSFP no contrast MRA and contrast-enhanced MRA (CE-MRA) in. Two experienced observers assessed the image quality, degree of venous contaminated and visibility of pedal artery branches by FSD-bSSFP and CE-MRA respectively in consensus. The signal intensity (SI), signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of the source images of both groups were measured and Wilcoxon and t tests were performed. Results: The image score of FSD-bSSFP group was 2.7±1.1 and CE-MRA was 2.6±0.8, there was no statistical difference (Z= 0.134, P>0.05). The image score of demonstration of the pedal artery branches and degree of venous contamination on FSD-bSSFP were 3.2±0.9 and 1.8±0.4 respectively which were superior to that of CE-MRA (2.5±0.9 and 2.1±0.8 respectively). Significant statistical difference existed between the two groups in demonstration of pedal artery branches (Z=5.246, P 0.05). But CNR of CE-MRA was superior to that of FSD-bSSFP and significant statistical difference existed between these two methods (t=5.113, P<0.01). Conclusion: FSD-bSSFP without contrast could be used in the evaluation of foot arteries in patients of renal dysfunction and diabetes. (authors)

  11. 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

  12. 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

  13. 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

  14. 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.)

  15. 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.

  16. 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

  17. 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 ...

  18. 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 ...

  19. 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 ...

  20. 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 ...

  1. Catheter Angiography

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    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 ...

  2. 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 ...

  3. Catheter Angiography

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    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 ( ...

  4. 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)

  5. 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.

  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. 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)

  8. Catheter Angiography

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    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 ...

  9. 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.

  10. 3D-CT angiography. Intracranial arterial lesions

    Energy Technology Data Exchange (ETDEWEB)

    Asato, Mikio; Tong, X.Q.; Tamura, Shozo [Miyazaki Medical Coll., Kiyotake (Japan)] [and others

    1997-06-01

    Since its introduction, three dimensional CT angiography (3D-CTA) on spiral (helical) CT has played an important role in clinical imaging. Initially it was reported to be useful in depicting aortic abnormalities, afterwards the merit in detecting intracranial aneurysm by 3D-CTA was also described. We have investigated the usefullness of 3D-CTA in detecting patients of intracranial aneurysm as well as arterio-venous malformation (AVM), Moyamoya disease and stenosis of middle cerebral artery, meanwhile the MR angiography (MRA) and digital subtraction angiography (DSA) examination of these patients were also studied as comparison to the 3D-CTA results. The sensitivity and specificity on investigating intracranial aneurysm were similar with other reports so far. 3D-CTA was possible to identify the feeding artery, nidus and draining vein of AVM, although DSA showed higher detectability. Occlusion of internal carotid artery and post-operative anastomosis in Moyamoya disease were all demonstrated by 3D-CTA, however the Moyamoya collaterals were shown better on MRA. 3D-CTA revealed the site of stenosis of middle cerebral artery in all of our cases, but in general maximum intensity projection (MIP) images can provide more exact information about the degree of stenosis. Five years has passed since the emergence of spiral CT and utilizing of 3D-CTA in clinical applications. With the development of hard and soft ware in the near future, it is possible to delineate more small vessels by 3D-CTA. We predict that 3D-CTA would be widely used for detecting vasculature of the whole body, and may take the place of conventional angiography in many cases. (author)

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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. ...

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    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 ...

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    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 ...

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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 ...

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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, ...

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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 ...

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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 ...

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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 ...

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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 ...

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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 ...

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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 ...

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    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. ...

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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 ...

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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 ...

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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 ...

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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 ...

  1. 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 ...

  2. 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 ...

  3. 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.

  4. MR respiratory navigator echo gated coronary angiography at 3 T

    International Nuclear Information System (INIS)

    Chang Shixin; Wang Yibin; Zong Genlin; Hao Nanxin; Du Yushan

    2007-01-01

    Objective: To investigate the techniques and influence factors for the respiratory navigator echo triggered whole-heart coronary MR angiography (WH-CMRA) and evaluate its application in visualizing coronary arteries and the image quality. Methods: Ninety two volunteers were acquired with WH-CMRA at 3 T MR scanner using respiratory navigator-echo gated TFE sequence. Imaging quality was visually graded as 0-IV grade according to the visual inspection, average length, diameter and sharpness of coronary arteries. The correlation between the imaging quality and respiratory pattern, heart rate and navigator efficiency was analyzed. Results: The imaging quality in 92 cases was that 28 were graded as IV, 53 were graded as III, 9 were graded as II and 2 were graded as I. The successful rate of scan was 88% (81/92). The imaging quality is mainly graded as IV when the heart rate was less than 75 beats per minute (bpm) and the sharpness of vessel was (48±11)%. When heart rate was more than 75 bpm, the image quality was mostly graded as 111 and the sharpness was (33±15)%. The correlation between heart rate and imaging quality score was negative (r= -0.726, P O.05). Conclusion: 3 T WH-CMRA technique could facilitated the visualization of whole coronary arteries at free breathing but having indications on heart rate. (authors)

  5. Significance of MR angiography in the diagnosis of aberrant renal arteries as the cause of ureteropelvic junction obstruction in children; Stellenwert der MR-Angiografie in der Diagnostik aberrierender Nierenarterien als Ursache einer Ureterabgangsstenose bei Kindern

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    Ritter, L.; Sorge, I.; Hirsch, F.W.; Vieweger, A. [Leipzig Univ. (Germany). Dept. of Pediatric Radiology; Goetz, G.; Lehnert, T.; Buehligen, U.; Geyer, C. [Leipzig Univ. (Germany). Dept. of Pediatric Surgery

    2015-01-15

    To determine the importance of MRI with contrast-enhanced MRA for the detection or exclusion of aberrant or obstructing renal arteries in ureteropelvic junction obstruction in children. Key word-based search in RIS database (ureteropelvic junction obstruction/MRI) and retrospective comparison of arterial findings from preoperative contrast-enhanced MRA and intra-operative inspection. From 2007 to 2013, 19 children with ureteropelvic junction obstruction underwent contrast-enhanced MRA. Based on the results of the MRI scan and MAG3 scintigraphy, the children were referred to surgery (Anderson-Hynes-pyeloplasty). An aberrant renal artery was diagnosed with MRI in 14 of 19 children, and intra-operative inspection confirmed 13 of those 14. In the remaining 5 children, no aberrant vessel could be observed in MRI and this was confirmed intra-operatively in 3 of the 5 cases, while in the remaining 2, an aberrant vessel was found. Of the 14 children with aberrant vessels, 12 underwent surgery due to assumed ureteral obstruction, which was confirmed by surgery in 11 cases. In one case, an aberrant artery was found intra-operatively, but obstruction could not be confirmed. In one of the 14 children, the vessel was found in MRI, but its obstructing character was negated via MRA, which was confirmed intra-operatively. In the diagnosis of aberrant and obstructing renal arteries, contrast-enhanced MRA presents 85 % sensitivity and 80 % specificity, with a positive predictive value of 0.8. MRI with contrast-enhanced MRA is suitable to detect aberrant and obstructing renal arteries. An obstructive effect of the aberrant vessel is to be assumed if the vessel has a close relationship to the ureteropelvic junction and if it is linearly stretched.

  6. 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 ...

  7. Catheter Angiography

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    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, ...

  8. Pediatric head and neck lesions: assessment of vascularity by MR digital subtraction angiography.

    Science.gov (United States)

    Chooi, Weng Kong; Woodhouse, Neil; Coley, Stuart C; Griffiths, Paul D

    2004-08-01

    Pediatric head and neck lesions can be difficult to characterize on clinical grounds alone. We investigated the use of dynamic MR digital subtraction angiography as a noninvasive adjunct for the assessment of the vascularity of these abnormalities. Twelve patients (age range, 2 days to 16 years) with known or suspected vascular abnormalities were studied. Routine MR imaging, time-of-flight MR angiography, and MR digital subtraction angiography were performed in all patients. The dynamic sequence was acquired in two planes at one frame per second by using a thick section (6-10 cm) selective radio-frequency spoiled fast gradient-echo sequence and an IV administered bolus of contrast material. The images were subtracted from a preliminary mask sequence and viewed as a video-inverted cine loop. In all cases, MR digital subtraction angiography was successfully performed. The technique showed the following: 1) slow flow lesions (two choroidal angiomas, eyelid hemangioma, and scalp venous malformation); 2) high flow lesions that were not always suspected by clinical examination alone (parotid hemangioma, scalp, occipital, and eyelid arteriovenous malformations plus a palatal teratoma); 3) a hypovascular tumor for which a biopsy could be safely performed (Burkitt lymphoma); and 4) a hypervascular tumor of the palate (cystic teratoma). Our early experience suggests that MR digital subtraction angiography can be reliably performed in children of all ages without complication. The technique provided a noninvasive assessment of the vascularity of each lesion that could not always have been predicted on the basis of clinical examination or routine MR imaging alone.

  9. The clinical application studies of CT spinal angiography with 64-detector row spiral CT in diagnosing spinal vascular malformations

    International Nuclear Information System (INIS)

    Gao Sijia; Zhang Mengwei; Liu Xiping; Zh Yushen; Liu Jinghong; Wang Zhonghui; Zang Peizhuo; Shi Qiang; Wang Qiang; Liang Chuansheng; Xu Ke

    2009-01-01

    Background and purpose: To explore the value of CT spinal angiography with 64-detector row spiral CT in diagnosing spinal vascular malformations. Methods: Seventeen patients with initial MR and clinical findings suggestive of spinal vascular diseases underwent CT spinal angiography. Among these, 14 patients took DSA examination within 1 week after CT scan, 7 patients underwent surgical treatment, and 6 patients underwent vascular intervention embolotheraphy. CT protocol: TOSHIBA Aquilion 64 Slice CT scanner, 0.5 mm thickness, 0.5 s/r, 120 kV and 350 mA, positioned at the aortic arch level, and applied with 'sure start' technique with CT threshold of 180 Hu. Contrast agent Iohexol (370 mg I/ml) was injected at 6 ml/s velocity with total volume of 80 ml. The post-processing procedures included MPR, CPR, MIP, VR, etc. Among the 17 patients, four patients underwent fast dynamic contrast-enhanced 3D MR angiography imaging. CT spinal angiography and three-dimensional contrast-enhanced MR angiography (3D CE-MRA) images were compared and evaluated with DSA and operation results based on disease type, lesion range, feeding arteries, fistulas, draining veins of vascular malformation by three experienced neuroradiologists independently, using double blind method. The data were analyzed using SPSS analytic software with χ 2 -test. We compared the results with DSA and operation results. Results: The statistical analysis of the diagnostic results by the three experienced neuroradiologists had no statistical difference (P > 0.05). All of the 17 patients showed clearly the abnormality of spinal cord vessels and the range of lesions by CT spinal angiography. Among them, one patient was diagnosed as arteriovenous fistulas (AVF) by MRI and CT spinal angiography, which was verified by surgical operation. DSA of the same patient, however, did not visualize the lesion. One case was diagnosed as AVM complicated with AVF by DSA, but CT spinal angiography could only show AVM not AVF. The

  10. The clinical application studies of CT spinal angiography with 64-detector row spiral CT in diagnosing spinal vascular malformations

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    Gao Sijia [Department of Radiology, No. 1 Affiliated Hospital of China Medical University, Shenyang 110001 (China)], E-mail: scarlettgao@126.com; Zhang Mengwei; Liu Xiping; Zh Yushen; Liu Jinghong; Wang Zhonghui [Department of Radiology, No. 1 Affiliated Hospital of China Medical University, Shenyang 110001 (China); Zang Peizhuo [Department of Neurosurgery, No. 1 Affiliated Hospital of China Medical University, Shenyang 110001 (China); Shi Qiang; Wang Qiang [Department of Radiology, No. 1 Affiliated Hospital of China Medical University, Shenyang 110001 (China); Liang Chuansheng [Department of Neurosurgery, No. 1 Affiliated Hospital of China Medical University, Shenyang 110001 (China); Xu Ke [Department of Radiology, No. 1 Affiliated Hospital of China Medical University, Shenyang 110001 (China)

    2009-07-15

    Background and purpose: To explore the value of CT spinal angiography with 64-detector row spiral CT in diagnosing spinal vascular malformations. Methods: Seventeen patients with initial MR and clinical findings suggestive of spinal vascular diseases underwent CT spinal angiography. Among these, 14 patients took DSA examination within 1 week after CT scan, 7 patients underwent surgical treatment, and 6 patients underwent vascular intervention embolotheraphy. CT protocol: TOSHIBA Aquilion 64 Slice CT scanner, 0.5 mm thickness, 0.5 s/r, 120 kV and 350 mA, positioned at the aortic arch level, and applied with 'sure start' technique with CT threshold of 180 Hu. Contrast agent Iohexol (370 mg I/ml) was injected at 6 ml/s velocity with total volume of 80 ml. The post-processing procedures included MPR, CPR, MIP, VR, etc. Among the 17 patients, four patients underwent fast dynamic contrast-enhanced 3D MR angiography imaging. CT spinal angiography and three-dimensional contrast-enhanced MR angiography (3D CE-MRA) images were compared and evaluated with DSA and operation results based on disease type, lesion range, feeding arteries, fistulas, draining veins of vascular malformation by three experienced neuroradiologists independently, using double blind method. The data were analyzed using SPSS analytic software with {chi}{sup 2}-test. We compared the results with DSA and operation results. Results: The statistical analysis of the diagnostic results by the three experienced neuroradiologists had no statistical difference (P > 0.05). All of the 17 patients showed clearly the abnormality of spinal cord vessels and the range of lesions by CT spinal angiography. Among them, one patient was diagnosed as arteriovenous fistulas (AVF) by MRI and CT spinal angiography, which was verified by surgical operation. DSA of the same patient, however, did not visualize the lesion. One case was diagnosed as AVM complicated with AVF by DSA, but CT spinal angiography could only show

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

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    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.)

  12. 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.)

  13. The emerging role of multidetector row CT angiography in the diagnosis of cervical arterial dissection: preliminary study

    International Nuclear Information System (INIS)

    Elijovich, Lucas; Kazmi, Khuram; Gauvrit, Jean Y.; Law, Meng

    2006-01-01

    Cervical artery dissection is an important cause of ischemic stroke, particularly in young patients. The diagnosis can be made with invasive catheter angiography or non-invasive imaging, either with MRI in conjunction with MR angiography (MRA) or CT angiography (CTA). Both modalities have been shown to have a high specificity and sensitivity. New developments such as multi-slice CTA (MSCTA) are emerging as an alternative methods for imaging the cervical and intracranial arteries. However, the contribution of modern MSCTA to carotid artery dissection has not been reported. We present a retrospective series of seven patients in whom both MSCTA and cervical axial T1 MRI and MRA were performed in the acute to subacute setting of internal carotid artery dissection. Carotid artery dissection was identified in all seven patients by MSCTA. The combination of MRI and MRA identified dissection in five of the seven patients. Additionally, a pseudoaneurysm was identified by MSCTA that was missed by MRI and MRA. Our findings confirm that MSCTA is a complementary technique in comparison to cervical axial T1 MRI and cervical MRA for diagnosing carotid artery dissection, and at times may provide additional information that can impact patient management. (orig.)

  14. Aneurysms in the vertebro-basilary flow region: standard protections (town and lateral projections), BASIS projections, and ispilateral inclined exposures; Multiprojektionale Angiographie zur Darstellung zerebraler Aneurysmen

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    Hering, M.; Zwicker, C. [Abt. fueer CT- und MRT-Diagnostik, Hegau-Klinikum Singen (Germany); Wakhloo, A.K.; Schumacher, M. [Sektion Neuroradiologie, Radiologische Universitaetsklinik, Freiburg (Germany)

    1998-07-01

    In spite of procedures such as CT angiography, MR angiography, and rotation angiography, panangiography is still indispensable in therapeutic planning for cerebral aneurysms. It is the only method that provides exact details about the size, anatomic localization, and multiplicity of aneurysms as well as relation to surrounding vessels, the presence of an aneurysmal neck, and for the evaluation of the collateral circulation required to answer the question if endovascular therapy is possible. In addition, panangiography still exhibits the highest selectivity in the detection of cerebral aneurysms. (orig.) [Deutsch] In einer retrospektiven Studie wurden die angiographischen und operativen Daten von 151 Patienten mit insgesamt 167 zerebralen Aneurysmen verglichen. Folgende Parameter wurden ausgewertet: Lokalisation, Multiplizitaet, Rupturzeichen, Morphologie und Groesse der Aneurysmen, ferner die Sensitivitaet der zerebralen Panangiographie im Vergleich zu den OP-Befunden. 47,9% der zerebralen Aneurysmen waren an der ACoA lokalisiert, 22,1% an der ACM und 10,8% an der PCoA. In 13,2% waren multiple Aneurysmen nachweisbar. 61,1% der Aneurysmen waren sackfoermig, 38,9% gelappt. Die Sensitivitaet der Angiographie betrug 95,4%. Fuer eine sichere Aneurysmadiagnostik erwiesen sich Darstellungen im posterio-anterioren, lateralen und beidseitig obliquen Strahlengang als obligates Minimalprogramm. Zusaetzliche Basisprojektionen erhoehten die Sensitivitaet bei Aneurysmen der A. communicans anterior und im vertebrobasilaeren Stromgebiet. Der Karotiskompressionstest war bei Aneurysmen der A. communicans anterior unabdingbar, bei Aneurysmen der A. communicans posterior zur Klaerung anatomischer Details geeignet. (orig.)

  15. Pediatric angiography

    International Nuclear Information System (INIS)

    Fitz, A.R.

    1987-01-01

    Angiography of the cerebral and visceral arterial systems is performed much less frequently than it was before the advent of computed tomographic scanning (CT). Most institutions have experienced at least a 50% reduction in the number of angiograms performed since installing a CT scanner. However, angiography still plays an important role in the confirmation of diagnoses made using a scanner, and in providing valuable information to the surgeon prior to excision of tumors or the repair of traumatized organs. Recently a number of sophisticated therapeutic procedures requiring vascular catheterization and the injection of contrast agents have been developed. In these procedures catheters are selectively placed in blood vessels perfusing a pathological process, such as an arteriovenous malformation, or at the site of an arterial stenosis; embolization of the arteriovenous malformation or tumor, or dilatation of the stenotic segment, is then performed. Whether the vessel catheterization is for diagnostic or therapeutic purposes, the basic approach is the same, and the technologist's duties are similar. The principal difference between a diagnostic and a therapeutic procedure is the length of time required to carry out the study; therapeutic procedures often require significantly longer periods of general anesthesia or sedation than do diagnostic studies

  16. MRI angiography

    International Nuclear Information System (INIS)

    Poncelet, B.; Baleriiaux, D.; struyven, J.; Segebarth, C.

    1989-01-01

    In MRI angiography two basis images are measured which only differ by the signal intensity of the flowing blood in the vessels. Subtraction of these two images produces a high contrast-to-noise representation of the vessels. Contrast between stationary tissues and flowing blood is changed, for one image compared to the second one, using a selective modification of the phase of the signal from the flowing blood, and/or using a selective modification of its longitudinal magnetization: The macroscopic spin motions along the selection and the measurement gradient directions affect the phase of the nuclear signal; assuming constant velocity, the phase is proportional to the velocity and to the first moment of the gradient waveforms applied. This work concentrates on the generarion of MRI angiograms, following a phase-based approach, of the carotid bifurcation and of different intracranical regions including the carotid syphon and the circle of Willis. (author). 21 refs.; 3 figs

  17. Radionuclide angiography

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    Heidenreich, P; Klotz, E

    1983-12-27

    RNA of common and internal carotid arteries as well as main cerebral arteries is the first component of cerebral serial scintigraphy. It should be the first diagnostic step in suspected cerebrovascular disease. In contrast to computed tomography RNA gives valuable information about cerebrovascular processes without morphological defects. RNA is superior of Doppler sonography in the evaluation of intracranial vascular disease. The simple and non-invasive RNA of the kidneys should be performed after renal transplantation (i.e. differential diagnosis of acute rejection and acute tubular necrosis), in suspected renal artery stenosis, renal infarction or in arterio-venous malformation of the kidneys. RNA is valuable in suspected occlusion of the abdominal aorta (infra- or suprarenal), aortic aneurysm or in stenosis of arteries in the pelvis or thighs. Postoperative controls can be carried out as often as desired. However, it cannot replace contrast angiography if vascular reconstruction is planned.

  18. Susceptibility-weighted angiography (SWAN) of cerebral veins and arteries compared to TOF-MRA

    International Nuclear Information System (INIS)

    Boeckh-Behrens, T.; Lutz, J.; Lummel, N.; Burke, M.; Wesemann, T.; Schöpf, V.; Brückmann, H.; Linn, J.

    2012-01-01

    Problem: High resolution, non-contrast imaging of both cerebral veins and arteries by use of gradient echo T2 star weighted angiography (SWAN) is a new method for susceptibility-weighted imaging with short acquisition times. We assessed the potential of this sequence for the depiction of both cerebral veins and arteries. Methods: 15 healthy volunteers were included in the study. MRI was performed on a 3 T MR scanner using the following sequences: (1) a 3D multi-echo gradient echo T2 star weighted angiography (SWAN), (2) an arterial 3D TOF MR angiography and (3) a venous 2D TOF. With regard to the SWAN sequence, both MinIP and MIP images were reconstructed and systematically compared to MIP reconstructions of the artTOF and the venTOF. To suggest possible clinical implications of our findings, we additionally included two illustrative cases. Results: With regard to the visualization of the cerebral veins, the MinIP reconstructions of the SWAN sequence were considerably superior compared to the venTOF. Concerning the depiction of the main segments of the big cerebral arteries the value of the MIP reconstructions of the SWAN was comparable to that of the artTOF with limitations in the homogenity and in the depiction of smaller arteries. Conclusions: SWAN allows for high-resolution visualization of both cerebral veins and arteries in one sequence without application of contrast agent and with significantly shortened scan time compared to the combined scan time of TOF-MRA and TOF-MRV. By use of either MinIP or MIP reconstructions, the arteries can be distinguished from the veins.

  19. Evaluation of intracranial arteriovenous malformations before and after embolization with dynamic MR digital subtraction angiography

    International Nuclear Information System (INIS)

    Chen Shuang; Feng Xiaoyuan; Baleriaux, D.; Metens, T.

    2005-01-01

    Objective: To evaluate the clinical utility and accuracy of dynamic MR digital subtraction angiography (MR-DSA) in the detection of intracranial arteriovenous malformations before and after embolization. Methods: A prospective blinded comparison of MR-DSA, 3D contrast-enhanced T 1 -weighted MR angiography (3D-CEMRA), proton-weighted imaging and conventional digital subtraction angiography (DSA) were underwent in 22 consecutive AVMs patients before and after embolization. Two readers independently interpreted images and compared with DSA images. Results: There was complete agreement between MR-DSA and DSA for classification and size of nidus before and after embolization in all cases. MR-DSA showed the modified hemodynamic features (the time of nidus, early venous enhancement delayed after carotid arteries appearance) in 17 cases, and nidus size were reduced in 13 cases (including 4 complete embolized cases) after embolization, which were 100% consistence compared with DSA. MR-DSA failed to depict 1 intranidal aneurysm and missed 1 less dilated artery and draining vein after embolization respectively, which were demonstrated clearly by 3D-CEMRA confirmed with DSA. The relatively more or less hyperintensity could be seen on proton-weighted imaging in all cases after embolization than before. Conclusion: MR-DSA is a fast, efficient, and noninvasive technique to provide hemodynamic information relevant for AVMs before and after embolization. Proton imaging is sensitive in delineation of the embolized region, MR-DSA, 3D-CEMRA and proton-weighted imaging should be combined in the evaluation and follow-up AVMs after partial embolization. (authors)

  20. 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)

  1. Exploiting magnetic resonance angiography imaging improves model estimation of BOLD signal.

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    Zhenghui Hu

    Full Text Available The change of BOLD signal relies heavily upon the resting blood volume fraction ([Formula: see text] associated with regional vasculature. However, existing hemodynamic data assimilation studies pretermit such concern. They simply assign the value in a physiologically plausible range to get over ill-conditioning of the assimilation problem and fail to explore actual [Formula: see text]. Such performance might lead to unreliable model estimation. In this work, we present the first exploration of the influence of [Formula: see text] on fMRI data assimilation, where actual [Formula: see text] within a given cortical area was calibrated by an MR angiography experiment and then was augmented into the assimilation scheme. We have investigated the impact of [Formula: see text] on single-region data assimilation and multi-region data assimilation (dynamic cause modeling, DCM in a classical flashing checkerboard experiment. Results show that the employment of an assumed [Formula: see text] in fMRI data assimilation is only suitable for fMRI signal reconstruction and activation detection grounded on this signal, and not suitable for estimation of unobserved states and effective connectivity study. We thereby argue that introducing physically realistic [Formula: see text] in the assimilation process may provide more reliable estimation of physiological information, which contributes to a better understanding of the underlying hemodynamic processes. Such an effort is valuable and should be well appreciated.

  2. [Development of an automated processing method to detect coronary motion for coronary magnetic resonance angiography].

    Science.gov (United States)

    Asou, Hiroya; Imada, N; Sato, T

    2010-06-20

    On coronary MR angiography (CMRA), cardiac motions worsen the image quality. To improve the image quality, detection of cardiac especially for individual coronary motion is very important. Usually, scan delay and duration were determined manually by the operator. We developed a new evaluation method to calculate static time of individual coronary artery. At first, coronary cine MRI was taken at the level of about 3 cm below the aortic valve (80 images/R-R). Chronological change of the signals were evaluated with Fourier transformation of each pixel of the images were done. Noise reduction with subtraction process and extraction process were done. To extract higher motion such as coronary arteries, morphological filter process and labeling process were added. Using these imaging processes, individual coronary motion was extracted and individual coronary static time was calculated automatically. We compared the images with ordinary manual method and new automated method in 10 healthy volunteers. Coronary static times were calculated with our method. Calculated coronary static time was shorter than that of ordinary manual method. And scan time became about 10% longer than that of ordinary method. Image qualities were improved in our method. Our automated detection method for coronary static time with chronological Fourier transformation has a potential to improve the image quality of CMRA and easy processing.

  3. Echo-planar MR imaging of dissolved hyperpolarized 129Xe. Potential for M angiography

    International Nuclear Information System (INIS)

    Maansson, S.

    2002-01-01

    Purpose: The feasibility of hyperpolarized 129 Xe for fast MR angiography (MRA) was evaluated using the echo-planar imaging (EPI) technique. Material and Methods: Hyperpolarized Xe gas was dissolved in ethanol; a carrier agent with high solubility for Xe (Ostwald solubility coefficient 2.5) and long relaxation times. The dissolved Xe was injected as a bolus into a flow phantom where the mean flow velocity was 15 cm/s. Ultrafast EPI images with 44 ms scan time were acquired of the flowing bolus and the signal-to-noise ratios (SNR) were measured. Results: The relaxation times of hyperpolarized Xe in ethanol were measured to T1=160±11 s and T2 ≅ 20 s. The resulting images of the flowing liquid were of reasonable quality and had an SNR of about 70. Conclusion: Based on the SNR of the obtained Xe EPI images; it was estimated that rapid in vivo MRA with 129 Xe may be feasible; provided that an efficient; biologically acceptable carrier for Xe can be found and polarization levels of more than 25% can be achieved in isotopically enriched 129 Xe

  4. 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.)

  5. Whole-heart MR coronary angiography - first results

    International Nuclear Information System (INIS)

    Ozgun, M.; Quante, M.; Fischbach, R.; Heindel, W.; Maintz, D.; Hoffmeier, A.; Botnar, R.

    2006-01-01

    Purpose: To evaluate a new coronary MR angiography technique covering the whole coronary artery tree in one data set acquisition. Materials and methods: Six healthy volunteers and 15 patients with known CAD were examined with a navigator gated and corrected (NAV) free-breathing 3D steady-state free precession sequence covering the whole heart (WH-MRA) (TR=5.4, TE-2.7, SENSE factor=2, 160 slices, 0.75 mm reconstructed slice thickness, in-plane resolution =0.99 x 0.99 mm 2 , scan time 14 min [50% NAV efficiency]) and a vessel targeted 3D SSFP MRA sequence (t-MRA) (TR=5.6 ms, TE-2.8 ms, 20 slices of 1.5 mm reconstructed slice thickness, in-plane resolution =0.99 x 0.99 mm 2 , scan time=7 min [50% NAV efficiency]). Subjective image quality (4-point scale) and objective image quality parameters including vessel sharpness, vessel diameter and CNR were calculated for WH-MRA and t-MRA. In patients, the accuracy for detection of stenosis larger than 50% was compared to the accuracy of X-ray coronary angiography (XA), which was considered the standard. Results: WH-MRA demonstrated good vessel visibility in healthy subjects (100%) whereas vessel visibility in patients was limited (78% in an 8 segment evaluation). Vessel sharpness was inferior to that of t-MRA in patients (37 vs. 42%) but equal in healthy subjects (42%). Vessel diameter did not differ significantly between WH-MRA and t-MRA. CNR was significantly reduced for WH-MRA (CNR 7.4 vs. 11.5). The diagnostic accuracy for the detection of CAD was comparable for both MRA approaches (85.5 vs. 86.2%). Conclusion: WH-MRA allows good coronary artery visualization in healthy subjects and patients and provides a simplified scanning procedure and advantages in 3D post-processing. Regarding image parameters and the detection of CAD, the results are comparable to those acquired with t-MRA. The major disadvantage remains the high number of diagnostically insufficient images. (orig.)

  6. Value of high spatial and high temporal resolution magnetic resonance angiography for differentiation between idiopathic and thromboembolic pulmonary hypertension: initial results

    Energy Technology Data Exchange (ETDEWEB)

    Ley, Sebastian; Eichinger, Monika [DKFZ, Department of Radiology (E010), Heidelberg (Germany); Johannes Gutenberg-University, Department of Radiology, University Hospital Mainz, Mainz (Germany); Fink, Christian; Zaporozhan, Julia; Puderbach, Michael; Plathow, Christian; Kauczor, Hans-Ulrich [DKFZ, Department of Radiology (E010), Heidelberg (Germany); Borst, Mathias M.; Meyer, F. Joachim; Gruenig, Ekkehard [University Heidelberg, Department of Internal Medicine, Heidelberg (Germany); Kreitner, Karl-Friedrich [Johannes Gutenberg-University, Department of Radiology, University Hospital Mainz, Mainz (Germany)

    2005-11-01

    Differentiation between different forms of pulmonary hypertension (PH) is essential for correct disease management. The goal of this study was to elucidate the clinical impact of high spatial resolution MR angiography (SR-MRA) and time-resolved MRA (TR-MRA) to differentiate between patients with chronic thromboembolic PH (CTEPH) and idiopathic pulmonary arterial hypertension (IPAH). Ten PH patients and five volunteers were examined. Twenty TR-MRA data sets (TA 1.5 s) and SR-MRA (TA 23 s) were acquired. TR-MRA data sets were subtracted as angiography and perfusion images. Evaluation comprised analysis of vascular pathologies on a segmental basis, detection of perfusion defects, and bronchial arteries by two readers in consensus. Technical evaluation comprised evaluation of image quality, signal-to-noise ratio (SNR) measurements, and contrast-media passage time. Visualization of the pulmonary arteries was possible down to a subsegmental (SR-MRA) and to a segmental (TR-MRA) level. SR-MRA outperformed TR-MRA in direct visualization of intravascular changes. Patients with IPAH predominantly showed tortuous pulmonary arteries while in CTEPH wall irregularities and abnormal proximal-to-distal tapering was found. Perfusion images showed a diffuse pattern in IPAH and focal defects in CTEPH. TR-MRA and SR-MRA resulted in the same final diagnosis. Both MRA techniques allowed for differentiation between IPAH and CTEPH. Therefore, TR-MRA can be used in the clinical setting, especially in dyspneic patients. (orig.)

  7. 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

  8. 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.)

  9. 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.)

  10. 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

  11. MRA versus digital subtraction angiography in acute subarachnoid haemorrhage: a blinded multireader study of prospectively recruited patients

    International Nuclear Information System (INIS)

    Jaeger, H.R.; Hausmann, O.; Moseley, I.F.; Taylor, W.J.; Mansmann, U.; Partzsch, U.

    2000-01-01

    We performed a blinded multireader study comparing MR angiography (MRA) with digital subtraction angiography (DSA) in 34 prospectively recruited patients who presented with acute subarachnoid haemorrhage (SAH). Two observers independently reviewed the MRA and DSA studies some months after clinical presentation. Presence of an aneurysm was rated on a 4-point confidence scale. Cases in which the initial interpretation of the observers varied were jointly reviewed to reach a consensus opinion. DSA was deliberately chosen not to represent the reference standard and the clinical course and surgical findings were used to explain significant differences between the consensus readings of MRA and DSA. Diagnostic confidence and interobserver agreement were, overall, higher on DSA than on MRA studies (κ DSA = 0.64 versus κ MRA = 0.52 with 95 % CI for Δ = κ DSA -κ MRA [-0.06, 0.31]). With both methods, discrepancies between observers were due to aneurysms overlooked rather than false-positive readings by one observer. Diagnostic accuracy therefore improved when the readings of the two observers were combined, particularly for MRA. Intermethod agreement was only fair and similar for both readers (κ reader 1 = 0.37 versus κ reader 2 = 0.32 with 95 % CI for Δ = κ reader 1 -κ reader 2 [-0.02, 0.11]). Both interobserver and intermethod agreements improved when the data were analysed on a per-study (positive or negative study) rather than on a per-aneurysm basis. Differences in the consensus reading were due to five aneurysms (four single and one multiple) detected only with MRA and five (two single and three multiple) detected only with DSA. MRA and DSA should be regarded as complementary in the investigation of patients with acute SAH. DSA can no longer be regarded as the reference standard. (orig.)

  12. Computed tomography angiography intraluminal filling defect is predictive of internal carotid artery free-floating thrombus

    Energy Technology Data Exchange (ETDEWEB)

    Jaberi, A.; Lum, C.; Stefanski, P.; Iancu, D. [University of Ottawa, Faculty of Medicine, Ottawa, Ontario (Canada); The Ottawa Hospital, Department of Radiology, Neuroradiology Section, Ottawa, Ontario (Canada); Thornhill, R. [Neurosciences and Clinical Epidemiology Program/Methods Centre, Ottawa Hospital Research Institute, Ottawa, Ontario (Canada); The Ottawa Hospital, Department of Radiology, Neuroradiology Section, Ottawa, Ontario (Canada); Petrcich, W. [Neurosciences and Clinical Epidemiology Program/Methods Centre, Ottawa Hospital Research Institute, Ottawa, Ontario (Canada); Momoli, F. [Children' s Hospital of Eastern Ontario Research Institute, Ottawa, Ontario (Canada); University of Ottawa, Department of Epidemiology and Community Medicine, Ottawa, Ontario (Canada); Torres, C.; Dowlatshahi, D. [University of Ottawa, Faculty of Medicine, Ottawa, Ontario (Canada); University of Ottawa, Division of Neurology, Department of Medicine, Ottawa, Ontario (Canada)

    2014-01-15

    Filling defects at the internal carotid artery (ICA) origin in the work-up of stroke or transient ischemic attack may be an ulcerated plaque or free-floating thrombus (FFT). This may be challenging to distinguish, as they can appear morphologically similar. This is an important distinction as FFT can potentially embolize distally, and its management differs. We describe a series of patients with suspected FFT and evaluate its imaging appearance, clinical features, and evolution with therapy. Between 2008 and 2013, we prospectively collected consecutive patients with proximal ICA filling defects in the axial plane surrounded by contrast on CT/MR angiography. We defined FFT as a filling defect that resolved on follow-up imaging. We assessed the cranial-caudal dimension of the filling defect and receiver operating characteristics to identify clinical and radiological variables that distinguished FFT from complex ulcerated plaque. Intraluminal filling defects were identified in 32 patients. Filling defects and resolved or decreased in 25 patients (78 %) and felt to be FFT; there was no change in 7 (22 %). Resolved defects and those that decreased in size extended more cranially than those that remained unchanged: 7.3 mm (4.2-15.9) versus 3.1 mm (2.7-3.7; p = 0.0038). Receiver operating characteristic analysis established a threshold of 3.8 mm (filling defect length), sensitivity of 88 %, specificity of 86 %, and area under the curve of 0.86 (p < 0.0001) for distinguishing FFT from plaque. Filling defects in the proximal ICA extending cranially >3.8 mm were more likely to be FFT than complex ulcerated plaque. Further studies evaluating filling defect length as a predictor for FFT are warranted. (orig.)

  13. 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

  14. 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.

  15. 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

  16. 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.)

  17. 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

  18. An investigation of cerebral magnetic resonance angiography (MRA). Part 8: diagnostic ability of cerebral aneurysms with MRA using 1.5 T MRI

    International Nuclear Information System (INIS)

    Ohue, Shiro; Kusunoki, Katsusuke; Kohno, Kanehisa

    1998-01-01

    The ability of MR angiography (MRA) to detect intracranial aneurysms was assessed. Seventy-eight patients, including 21 cases of intracranial aneurysms, underwent three-dimensional time-of-flight (3D TOF) MRA using a 1.5 T MRI system. MRA images were evaluated using maximum intensity projection (MIP) images only, MIP+selective MIP images, and MIP+selective MIP+original images by ten neurosurgeons and neuroradiologists. By receiver operating characteristic (ROC) analysis of the ability to detect the 21 patients with aneurysms, the sensitivity of MIP images was 74±8% (mean±S.D.) while the specificity was 80%. Of 26 aneurysms, the sensitivity of MIP images was 64±9% (mean±S.D.). Although the sensitivity for aneurysms 5 mm or larger, or located at middle cerebral arteries was over 85%, the sensitivity for aneurysms smaller than 5 mm or located at internal carotid arteries was less than 50%. The evaluation of MRA adding selective MIP and original images to MIP images improved the sensitivity in detecting aneurysms and decreased the number of false positive cases. These data indicate that MRA is a useful technique for detecting aneurysms 5 mm or larger, and those located at the middle cerebral arteries. However, by MRA, it remains difficult to detect aneurysms smaller than 5 mm and those located at the internal carotid arteries. (author)

  19. 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.)

  20. High prevalence of intracranial aneurysms in patients with aortic dissection or aneurysm: feasibility of extended aorta CT angiography with involvement of intracranial arteries.

    Science.gov (United States)

    Lee, Dahye; Ahn, Sung Jun; Cho, Eun-Suk; Kim, Yong Bae; Song, Suk-Won; Jung, Woo Sang; Suh, Sang Hyun

    2017-10-01

    Previous studies have suggested a higher prevalence of intracranial aneurysms (IAs) in patients with aortic aneurysms (AAs). To carry out a preliminary study to evaluate the prevalence of IAs in these patients and the diagnostic feasibility of extended aorta CT angiography (CTA), including intracranial arteries as well as the aorta. We retrospectively reviewed all patients with a clinical diagnosis of AA or aortic dissection (AD) who had undergone aorta CTA as well as MR angiography, CTA, and/or DSA of the brain between 2009 and 2014. Since 2012, the extended aorta CTA protocol has been applied in these patients. Characteristics of IAs were classified with baseline clinical data. For quantitative and qualitative assessment by two independent raters, brain images obtained by extended aorta CTA and brain CTA were compared. The radiation dose of the two aorta protocols was compared. The prevalence of IA was 22.2% (35/158). All IAs were detected by extended aorta CTA, except one small aneurysm (product of the extended aorta CTA increased with increment of the scan range (p=0.048). With a high prevalence of IAs in patients with ADs or AAs, extended aorta CTA could be used to evaluate aorta disease and IA in a single session. However, further prospective studies are needed to prove efficacy and safety of the extended aorta CTA protocol in patients with AAs or ADs. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  1. 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

  2. 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.

  3. 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

  4. Angiography in renal tuberculosis

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Doo Suk [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    1974-10-15

    Angiographies on forty cases of renal tuberculosis performed at the National Medical Center during a period 1960 through 1970 were reviewed. Abdominal angiography was performed via the femoral route. Some were followed by selective nephroangiography. All patients were subjected to urographyior to angiography. The results of X-ray findings in the forty cases with renal tuberculosis were follows. 1. The age varied 18 to 57 years, average 30.5 years. Twenty one patients were male, and nineteen were female. 2. The right kidney was involved in 17 cases and the left in 15 cases. Both kidneys were involved in 8 cases. 3. Urographic examination revealed pathologic changes in all patients. 4. Focal destruction in the collecting system was the most common finding in the urography of 16 patients. 5. A varying degree of hydronephrosis was present in 15 patients, of whom nine had complained of palpable mass due to hydronephrosis. 6. In the 7 patients with extensive destruction there was no observable excretion contrast medium from the diseased kidney. 7. Angiographic examination was normal in 6 of the 40 patients. 8. Decreased vascularity in the subsegmental or smaller arteries of the affected kidney was the most frequent finding, being found in 34 patients. 9. Occlusion or abrupt termination of the subsegmental arteries was present in 4 patients. 10. Eighteen of the patients had signs of an expansive process within the cavity, the vessels being displaced and stretched around the lesions.

  5. Estudo da circulação hepatomesentérica pela angiografia por ressonância magnética com gadolínio: comparação entre doses simples e dupla no estudo de pacientes esquistossomóticos Gadolinium-enhanced magnetic resonance angiography for hepatomesenteric vascular evaluation: single and double doses comparison in schistosomiasis patients

    Directory of Open Access Journals (Sweden)

    Rogério Pedreschi Caldana

    2006-08-01

    Full Text Available OBJETIVO: Determinar a freqüência de visualização dos segmentos da circulação hepatomesentérica pela angiografia por ressonância magnética (angio-RM com contraste e comparar o valor do método, utilizando-se duas diferentes dosagens de gadolínio (doses simples e dupla. MATERIAIS E MÉTODOS: Estudo prospectivo de 36 pacientes esquistossomóticos submetidos a angio-RM. Os exames foram realizados em equipamento de RM de 1,5 T, usando-se bobina de corpo e bomba injetora para a administração endovenosa do contraste. Foram utilizadas, de maneira randomizada, dose dupla do contraste paramagnético (0,2 mmol/kg de Gd-DTPA em 21 pacientes e dose simples (0,1 mmol/kg em outros 15 pacientes. Os exames foram interpretados por dois observadores em consenso, que classificaram o grau de visualização de 25 segmentos vasculares estabelecidos para análise, sem conhecimento da dose de gadolínio utilizada. RESULTADOS: Os segmentos vasculares proximais e de maior calibre foram as estruturas com melhor grau de visualização na maioria da amostra em estudo. O tronco celíaco, a artéria hepática comum, a artéria esplênica, a croça e terço médio da artéria mesentérica superior, a veia porta, a veia esplênica e a veia mesentérica superior apresentaram grau 2 de visualização em mais de 70% da amostra. Quanto à comparação das diferentes dosagens, não houve diferença significante (p OBJECTIVE: To evaluate the visibility of hepatomesenteric vascular segments by 3D gadolinium-enhanced magnetic resonance (MR angiography and to compare the method effectiveness between two different gadolinium doses (single and double doses. MATERIALS AND METHODS: A prospective study was performed with 36 schistosomiasis patients who were submitted to 3D contrast-enhanced MR angiography. Scans were performed in a high-field equipment (1.5 T, with body coil and power injector for intravenous contrast administration. Contrast double doses (Gd-DTPA 0.2 mmol/kg and

  6. 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

  7. 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

  8. Intraarterial digital subtraction angiography

    International Nuclear Information System (INIS)

    Davis, P.C.

    1987-01-01

    Digital subtraction angiography (DSA) refers to a radiographic technique of amplifying low levels of contrast from intravascular iodine into an acceptable image of vascular anatomy. Initial enthusiasm suggested that DSA using intravenous injections (IV-DSA) would eliminate most conventional film-screen angiographic studies. It was soon apparent, however, that IV-DSA examinations were often compromised in those patients who most needed a less invasive study. Indeed, only a 70 to 85 percent accuracy rate was achieved with IV-DSA, primarily due to motion artifact, poor cardiac output, overlap of pertinent vessels, and inability to resolve smaller vessels

  9. Digital subtraction angiography

    International Nuclear Information System (INIS)

    Neuwirth, J. Jr.; Bohutova, J.

    1987-01-01

    The quality of radiodiagnostic methods to a great extent depends on the quality of the resulting image. The basic technical principles are summed up of the different parts of digital subtraction angiography apparatus and of methods of improving the image. The instrument is based on a videochain consisting of an X-ray tube, an intensifier of the radiographic image, optical parts, a video camera, an analog-to-digital converter and a computer. The main advantage of the digitally processed image is the possibility of optimizing the image into a form which will contain the biggest amount of diagnostically valuable information. Described are the mathematical operations for improving the digital image: spatial filtration, pixel shift, time filtration, image integration, time interval differentation and matched filtering. (M.D.). 8 refs., 3 figs

  10. 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.)

  11. 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)

  12. 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

  13. 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

  14. 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.

  15. MR imaging of persistent primitive trigeminal artery

    International Nuclear Information System (INIS)

    Ashikaga, Ryuichiro; Araki, Yutaka; Ono, Yukihiko; Ishida, Osamu; Mabuchi, Nobuhisa.

    1997-01-01

    The persistent trigeminal artery is the most common anomaly of the primitive carotid-vertebrobasilar anastomoses. We reviewed MR images and MR angiographies of 11 patients with primitive trigeminal artery. In 8 of the 11 cases, PTA were identified with conventional long TR spin-echo images. In 8 of 11 cases, a hypoplastic basilar trunk associated with PTA was seen on both MR images and MR angiographies. In 7 of 11 cases, a hypoplasia or agenesis of the ipsilateral posterior communicating artery was seen on MR angiographies. (author)

  16. Multislice CT angiography

    Energy Technology Data Exchange (ETDEWEB)

    Prokop, Mathias E-mail: mathias.prokop@univie.ac.at

    2000-11-01

    Multislice CT has overcome past limitations of CT angiography (CTA): Scan length and spatial resolution can be simultaneously optimized with multislice CTA, contrast medium can be saved, and the evaluation of large anatomic areas and vessels smaller than 1 mm become possible. This article describes how to optimize scanning protocols and contrast injection, and discusses the main clinical applications of this new technique. Only three main scanning protocolssuffice for all indications. A high speed / high-volume protocol (using 4*2mm or 4*2.5mm collimation) can be employed to scan the chest or abdomen in 8-10s, or to cover the whole abdominal aorta and the peripheral runoff including the feet within 40-65s. A high resolution protocol (using 4*1mm or 4*1.25mm) can be employed for the aorta and most regional vascular beds. It allows for near isotrophic imaging and depicts fine vascular structures with excellent detail. Ultra-high resolution protocols (using 2*0.5mm or 4*0.5mm collimation) yield totally isotropic data sets, and are mainly reserved for cerebrovascular imaging. Image processing techniques, and, in particular, volume rendering have made image presentation faster and easier. Multislice CTA exceeds MRA in spatial resolution and is now able to display even small vascular side branches. Its main indications will be aortic diseases, suspected pulmonary embolism but also renal artery stenoses, preoperative workup of abdominal or cerebral vessels, and acute vascular diseases. Multisplice CTA will become a strong competitor of other minimally invasive vascular imaging techniques.

  17. Intracranial tumors in pediatric patients; Intrakranielle Tumoren im Kindesalter

    Energy Technology Data Exchange (ETDEWEB)

    Reith, W. [Universitaetsklinikum Saarland, Homburg (Germany). Klinik fuer Diagnostische und Interventionelle Neuroradiologie; Hagen, T. [Radiologengemeinschaft, Augsburg (Germany)

    2007-06-15

    Every year, 400 children suffer from a brain tumor. These are the most frequent solid tumors in the pediatric patient. They represent a very heterogenic group of tumors with different clinical symptoms, pathology, therapy and prognosis. Imaging modalities such as CT and MRI are important for the diagnosis and follow-up after therapy. Brain tumors in children are responsible for 15-20% of all brain tumors. Tumors of the central nervous system are the second most common tumors after leukemia. Infra- and supratentorial tumors occur in equal number, however, there are differences in the age of occurrence: supratentorial tumors occur more often within the first 2-3 years of life, whereas infratentorial tumors reach there peak between 4 and 10 years. After the tenth year, infra- and supratentorial tumors occur with equal frequency. (orig.)

  18. 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)

  19. 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.

  20. 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 ...

  1. Pulmonary vein dimensions and variation of branching pattern in patients with paroxysmal atrial fibrillation using magnetic resonance angiography

    International Nuclear Information System (INIS)

    Takase, Bonpei; Nagata, Masayoshi; Matsui, Takemi

    2004-01-01

    Pulmonary veins are the most frequent origin of focal and paroxysmal atrial fibrillation. Although radiofrequency ablation has been attempted for the treatment of focal and paroxysmal atrial fibrillation, the anatomy of the pulmonary vein is still not fully understood. To investigate the dimensions and anatomical variation of the pulmonary vein in patients with paroxysmal atrial fibrillation, we performed breath-hold gadolinium enhanced magnetic resonance (MR) angiography using a 1.5 T cardiac MR imager (GE CV/i) in 32 patients with paroxysmal atrial fibrillation (61±8 years old), 11 patients with chronic atrial fibrillation (64±9 years old), and 26 patients with normal sinus rhythm (55±15 years old). Three-dimensional images of the pulmonary veins were thus obtained, and the diameters of the most proximal portion of the left or right superior pulmonary vein and left or right inferior pulmonary vein were measured. Pulmonary vein branching variations were determined by a visual qualitative analysis by two separate readers' agreements, who were blinded to any clinical information. We focused on the existence of a complex-branching pattern draining into the orifice of four pulmonary veins. Patients with either paroxysmal atrial fibrillation or chronic atrial fibrillation showed larger superior pulmonary veins than those with normal sinus rhythm (mean±SD; in the left superior pulmonary vein, 20±3 mm 23±3 mm vs 16±3 mm, P<0.05; in right superior pulmonary vein, 19±4 mm, 19±2 mm vs 16±2 mm, P<0.05). Complex-branching pattern was frequently observed in inferior pulmonary veins in patients with either paroxysmal atrial fibrillation or chronic atrial fibrillation; 25/32 patients with paroxysmal atrial fibrillation, 11/11 patients with chronic atrial fibrillation, compared to 7/26 patients with normal sinus rhythm. Complex-branching patterns were not observed in superior pulmonary veins in any patients in this cohort. In patients with paroxysmal atrial fibrillation

  2. Digital subtraction angiography in traumatology

    International Nuclear Information System (INIS)

    Steudel, A.; Harder, T.; Lackner, K.; Schneider, B.; Orellano, L.; Bonn Univ.; Bonn Univ.

    1986-01-01

    The methods, indications and results of digital subtraction angiography in traumatology are presented, based on 56 examinations. The different use of intravenous or intraarterial DSA will be discussed with respect to expanding and localisation of traumatic vascular injury. DSA is recommended as the method of choice for follow-up after vascular reconstructive procedure. (orig.) [de

  3. 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

  4. Intracardiac and intracerebral thrombosis associated with ...

    African Journals Online (AJOL)

    Although thromboembolic events in nephrotic syndrome (NS) are seen less often in ... occurs, causing atherosclerosis and vascular thrombosis. Mutations .... Cranial diffusion magnetic resonance (MR) and MR angiography showed brain.

  5. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... also screened for safety in the magnetic environment. Children will be given appropriately sized earplugs or headphones ... have special pediatric considerations. The teddy bear denotes child-specific content. Related Articles and Media MR Angiography ( ...

  6. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... used in tattoos may contain iron and could heat up during an MRI scan, but this is ... called MR angiography (MRA) provides detailed images of blood vessels in the brain—often without the need ...

  7. 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 | ...

  8. MRI of the Chest

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

  9. MRI of the Chest

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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 MR Angiography (MRA) Magnetic ...

  10. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... MRI) procedure 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 MR Angiography (MRA) Magnetic ...

  11. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... food, or the environment, or if you have asthma. The contrast material most commonly used for an ... have special pediatric considerations. The teddy bear denotes child-specific content. Related Articles and Media MR Angiography ( ...

  12. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... scanner. top of page How does the procedure work? Unlike conventional x-ray examinations and computed tomography ( ... have special pediatric considerations. The teddy bear denotes child-specific content. Related Articles and Media MR Angiography ( ...

  13. MRI of the Chest

    Medline Plus

    Full Text Available ... This detail makes MRI an invaluable tool in early diagnosis and evaluation of cardiovascular conditions. MRI has ... have special pediatric considerations. The teddy bear denotes child-specific content. Related Articles and Media MR Angiography ( ...

  14. Magnetic resonance angiography (MRA) of the calf station at 3.0 T: intraindividual comparison of non-enhanced ECG-gated flow-dependent MRA, continuous table movement MRA and time-resolved MRA

    International Nuclear Information System (INIS)

    Haneder, Stefan; Attenberger, Ulrike I.; Riffel, Philipp; Henzler, Thomas; Schoenberg, Stefan O.; Michaely, Henrik J.

    2011-01-01

    To compare 3D non-enhanced ECG-gated inflow-dependent MRA (NE-MRA) vs. continuous table movement (CTM) MR-angiography and time-resolved TWIST-MRA in the calf station at 3.0 T in a clinical patient collective. 36 patients (27 male/9 female, 66.1 ± 14.4 years) with PAOD (stage II-IV) underwent during a single MRI: NE-MRA, contrast-enhanced CTM-MRA and TWIST-MRA with a single dose of a gadolinium-based contrast agent. The image quality (IQ) and the degree of stenoses were rated on a four-point scale. Positive (PPV) and negative predictive values (NPV), sensitivity (SS) and specificity (SP) for stenoses detection were calculated for NE-MRA vs. CTM-MRA and vs. TWIST-MRA. Values were obtained for overall graduation of wall changes and for severe stenoses (>70%). With NE-MRA 122/288 segments were not assessable. Compared with CTM-MRA and TWIST-MRA the IQ was significantly inferior (p < 0.0001 to p = 0.0426). CTM-MRA/TWIST-MRA detected stenoses in 44.9%/46.1% of the segments, NE-MRA in 53.5%. SS/NPV of the NE-MRA ranged from 97.8 to 100%. The SP and PPV ranged from 72.7 to 85.5% and 66.7 to 78.2%. Contrast-enhanced MRA techniques are superior to NE-MRA regarding IQ and correct identification of stenoses. If technically successful, NE-MRA is characterised by high NPV and overestimation of the degree of stenoses. (orig.)

  15. 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.

  16. Pulmonary angiography with lopamidol 370

    International Nuclear Information System (INIS)

    Braun, S.D.; Saeed, M.; Perlmutt, L.M.; Newman, G.E.; Illescas, F.F.; Cohan, R.H.; Dunnick, N.R.

    1986-01-01

    Fifty-one consecutive patients who underwent pulmonary angiography with iopamidol, 370 mg/ml, were studied prospectively. Patients were asked to grade any heat or pain felt on injection, and were observed for coughing. Right atrial and pulmonary artery pressures were obtained before the first and after the final contrast agent injection. Pressure changes were compared with those in a consecutive group of 25 patients who underwent examinations performed with Na-meglumine diatrizoate, 370 mg/ml. Film quality was evaluated for patient motion. Iopamidol generated marked discomfort in only three patients. Pressure changes were largely unremarkable. In no case was there any significant motion artifact secondary to coughing. Iopamidol is a safe, well-tolerated contrast agent for pulmonary angiography. It improves image quality by nearly eliminating coughing

  17. 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.)

  18. 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.

  19. 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

  20. 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

  1. 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.)

  2. 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 ...

  3. Exercise intravenous digital subtraction angiography

    International Nuclear Information System (INIS)

    Yiannikas, J.

    1986-01-01

    Attempts to use exercise ventriculography have been made, not only to give diagnostic and perhaps even prognostic information in patients with coronary artery disease, but also in patients with valvular heart disease both before and after surgical intervention. Clearly an accurate method of assessing ventricular function under conditions of stress in various cardiac diseases would provide important information that would help in patient management. Exercise ventriculography using gated blood pool equilibrium technetium studies are widely used, but are limited by spatial resolution and by the foreshortening affects of visualizing the left ventricular chamber in the left anterior oblique view. First pass radionuclide studies have the added advantage of being able to visualize the ventricular chamber in the anterior or even the right anterior oblique view, but are even more limited by their spatial resolution problems. Several investigations have shown that digital subtraction angiography produces left ventricular images with a spatial resolution almost identical to that of conventional contrast ventriculography, but without the inherent problems of cardiac arrhythmias, which often limit the assessment of left ventricular function. Because of its ability to accurately delineate wall motion abnormalities, the technique may provide an adequate assessment of global and regional left ventricular function after exercise. Digital subtraction angiography may identify ischemic wall motion abnormalities produced by exercise in patients who already had significant permanent left ventricular damage from myocardial infarction

  4. Minimally invasive superficial temporal artery to middle cerebral artery bypass through a minicraniotomy: benefit of three-dimensional virtual reality planning using magnetic resonance angiography.

    Science.gov (United States)

    Fischer, Gerrit; Stadie, Axel; Schwandt, Eike; Gawehn, Joachim; Boor, Stephan; Marx, Juergen; Oertel, Joachim

    2009-05-01

    The aim of the authors in this study was to introduce a minimally invasive superficial temporal artery to middle cerebral artery (STA-MCA) bypass surgery by the preselection of appropriate donor and recipient branches in a 3D virtual reality setting based on 3-T MR angiography data. An STA-MCA anastomosis was performed in each of 5 patients. Before surgery, 3-T MR imaging was performed with 3D magnetization-prepared rapid acquisition gradient echo sequences, and a high-resolution CT 3D dataset was obtained. Image fusion and the construction of a 3D virtual reality model of each patient were completed. In the 3D virtual reality setting, the skin surface, skull surface, and extra- and intracranial arteries as well as the cortical brain surface could be displayed in detail. The surgical approach was successfully visualized in virtual reality. The anatomical relationship of structures of interest could be evaluated based on different values of translucency in all cases. The closest point of the appropriate donor branch of the STA and the most suitable recipient M(3) or M(4) segment could be calculated with high accuracy preoperatively and determined as the center point of the following minicraniotomy. Localization of the craniotomy and the skin incision on top of the STA branch was calculated with the system, and these data were transferred onto the patient's skin before surgery. In all cases the preselected arteries could be found intraoperatively in exact agreement with the preoperative planning data. Successful extracranial-intracranial bypass surgery was achieved without stereotactic neuronavigation via a preselected minimally invasive approach in all cases. Subsequent enlargement of the craniotomy was not necessary. Perioperative complications were not observed. All bypasses remained patent on follow-up. With the application of a 3D virtual reality planning system, the extent of skin incision and tissue trauma as well as the size of the bone flap was minimal. The

  5. 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

  6. [Nursing care in fluorescein angiography].

    Science.gov (United States)

    Santos-Blanco, Feliciano

    2008-01-01

    Fluoresceinic angiography of the ocular fundus is a diagnostic technique to study retinal and choroidal circulation. This technique consists of parenteral administration of 500 mg of sodium fluorescein 10% and photographing the fluorescence in the eye vessels. Although this substance is fairly safe, it may also produce mild, moderate or severe local and/or general adverse reactions. The nursing process is routinely used in hospital units but not always in outpatient clinics, even through the use of invasive procedures with intravenous medication administration is common. Therefore, nurses, as those reponsible for intravenous administration, should use the nursing process to guarantee the quality of care required by the patient. To do this, we describe an individualized care plan based on evaluation by Marjorie Gordon's functional health patterns, NANDA's nursing diagnoses Taxonomy II, Nursing Outcomes Classification (NOC), Nursing Interventions Classifications (NIC) and potential complications of the procedure.

  7. Angiography of primary bone tumors

    International Nuclear Information System (INIS)

    Keyl, W.; Kunkel, B.

    1982-01-01

    To determine the type of a tumour by means of angiography is problematical. Considering that tumour-simulating lesions (myositis ossificans, modular synoritis) can also show pathological blood vessel formations and AV-shunts the interpretation of vessel-architectonic criteria must be done very carefully. The finding of some individual signs of malignancy does not justify the diagnosis of ''malignant tumour''. Only the ''anarchic vessel picture'' (Freyschmidt) with changing caliber, corkscrew vessels, interrupted vessels, unregular tumour colouring, arteria-venous shunts and possibly also tumour invasion into vessels makes a malignant process very likely. The absence of these criteria, however, does not exclude malignancy. Non-vascularised malignant tumours can only lead to a displacement of vessels without an angiographic proof of the tumour itself. (orig./APR) [de

  8. 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...

  9. 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)

  10. 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

  11. 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

  12. 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 ...

  13. Your Radiologist Explains Magnetic Resonance Angiography (MRA)

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    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 ...

  14. 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 ...

  15. Your Radiologist Explains Magnetic Resonance Angiography (MRA)

    Medline Plus

    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 ...

  16. Your Radiologist Explains Magnetic Resonance Angiography (MRA)

    Medline Plus

    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 ...

  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. 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.

  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. Digital angiography of camel foot

    International Nuclear Information System (INIS)

    Dehghani, S.N.; Kohkiloyehzadeh, M.; Sazmand, A.

    2011-01-01

    In this study, angiography of normal digits of camel has been accomplished, and the vessels of digits and its distribution have been evaluated to be compared with abnormal digits in the future studies. The thoracic and pelvic limb of 16 camels were collected immediately following slaughter. The palmar and plantar arteries were isolated and catheterised by 18-gauge angiocatheter needle; perfused by 40Ð’–50 ml of iodinated compound injected into each vessel. Angiograms were obtained using dorsopalmer, dorsoplanter and latero-medial projections. In the pelvic limb, above the fetlock joint, the deep palmar arch communicates with the median artery via the anastomotic branch, forming the superfcial palmar arch, from which two branches were clear, 1-palmar common digital artery IV that divides into palmar proper digital arteries IV and V, close to the lateral accessory (ffth) digit. 2-Palmar common digital artery III, produces the first branch and continues distally near the middle of the proximal phalanx, it gives off two palmar branches of the proximal phalanx. Vascular distribution of the pelvic limb was similar to thoracic limb, carrying the name of plantar instead of palmar

  1. 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

  2. Correlation between coronary computed tomographic angiography and fractional flow reserve

    DEFF Research Database (Denmark)

    Kristensen, Thomas Skaarup; Engstrøm, Thomas; Kelbæk, Henning

    2010-01-01

    Coronary CT angiography (CCTA) has become an important modality to evaluate the presence of coronary artery disease. Coronary artery stenosis of intermediate severity remains a therapeutic dilemma. Measurement of fractional flow reserve (FFR) during coronary angiography is the most established...

  3. 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

  4. 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.

  5. Digital subtraction angiography of the thoracic aorta

    International Nuclear Information System (INIS)

    Grossman, L.B.; Buonocore, E.; Modic, M.T.; Meaney, T.F.

    1984-01-01

    Forty-three patients with acquired and congenital abnormalities of the thoracic aorta were studied using digital subtraction angiography (DSA) after an intravenous bolus injection of 40 ml of contrast material. Abnormalities studied included coarctation, pseudocoarctation, Marfan syndrome, cervical aorta, double aortic arch, aneurysm, dissection, and tumor. Twenty-four patients also had conventional angiography. DSA was accurate in 95% of cases; in the other 5%, involving patients with acute type I dissection, the coronary arteries could not be seen. The authors concluded that in 92% of their patients, DSA could have replaced the standard aortogram

  6. Digital subtraction angiography of the thoracic aorta

    Energy Technology Data Exchange (ETDEWEB)

    Grossman, L.B.; Buonocore, E.; Modic, M.T.; Meaney, T.F.

    1984-02-01

    Forty-three patients with acquired and congenital abnormalities of the thoracic aorta were studied using digital subtraction angiography (DSA) after an intravenous bolus injection of 40 ml of contrast material. Abnormalities studied included coarctation, pseudocoarctation, Marfan syndrome, cervical aorta, double aortic arch, aneurysm, dissection, and tumor. Twenty-four patients also had conventional angiography. DSA was accurate in 95% of cases; in the other 5%, involving patients with acute type I dissection, the coronary arteries could not be seen. The authors concluded that in 92% of their patients, DSA could have replaced the standard aortogram.

  7. Clinical application of digital subtraction angiography (DSA)

    International Nuclear Information System (INIS)

    Morimoto, Tadashi; Kaku, Suiei; Morikawa, Eiji

    1984-01-01

    Intra-arterial digital subtraction angiography (IA-DSA) by the direct puncture of the carotid artery was described with special reference to its techniques, and cases were presented. This method was safe and painless and could be performed repeatedly. Cerebral angiographic images obtained by this method were either superior or fully compatible to the conventional cerebral angiography. It is therefore of great diagnostic value and can replace the conventional method. Furthermore, since the pretreatment is unnecessary and the time required is short, IA-DSA can be used as an adjuvant method for emergency diagnosis. (Namekawa, K)

  8. 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

  9. 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.

  10. 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)

  11. Hodgkin's disease following thorium dioxide angiography

    Energy Technology Data Exchange (ETDEWEB)

    Gotlieb, A I; Kirk, M E [McGill Univ., Montreal, Quebec (Canada). Dept. of Pathology; Hutchison, J L [Montreal General Hospital, Quebec (Canada)

    1976-09-04

    Hodgkin's disease occurred in a 53-year-old man who, 25 years previously, had undergone cerebral angiography, for which thorium dioxide suspension (Thorotrast) was used. Deposits of thorium dioxide were noted in reticuloendothelial cells in various locations. An association between thorium dioxide administration and the subsequent development of malignant tumours and neoplastic hematologic disorders has previously been reported.

  12. Digital subtraction angiography: myths and reality

    International Nuclear Information System (INIS)

    Levin, D.C.

    1984-01-01

    Some of the claims made about digital subtraction angiography (DSA) when it was first developed have turned out to be greatly exaggerated, and some members of the radiologic community have become disillusioned with its capabilities. The author discusses some of the limitations of DSA, and concludes that the advantages of DSA outweigh its limitations

  13. Spiral CT-angiography of the aorta

    NARCIS (Netherlands)

    Balm, R.; Eikelboom, B. C.; van Leeuwen, M. S.; Noordzij, J.

    1994-01-01

    AIMS: To determine whether the new technique of CT-angiography was accurate in displaying the complex anatomy of the aorta and its major branches. METHODS: Seventeen patients with a variety of aortic pathology were examined. Using a spiral CT-scanner a volumetric scan was made during injection of

  14. 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.)

  15. 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

  16. Digital subtraction angiography of carotid bifurcation

    International Nuclear Information System (INIS)

    Vries, A.R. de.

    1984-01-01

    This study demonstrates the reliability of digital subtraction angiography (DSA) by means of intra- and interobserver investigations as well as indicating the possibility of substituting catheterangiography by DSA in the diagnosis of carotid bifurcation. Whenever insufficient information is obtained from the combination of non-invasive investigation and DSA, a catheterangiogram will be necessary. (Auth.)

  17. 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 ...

  18. Conventional cerebral angiography in occlusive cerebrovascular disease

    International Nuclear Information System (INIS)

    Caplan, L.R.; Wolpert, S.M.

    1987-01-01

    Treatment of the patient with occlusive vascular lesions of the extracranial and intracranial arteries will depend on the location, nature, and severity of the vascular disease and the general and neurologic condition of the patient. At present, standard angiography is the best method of opacifying the vascular system to gain critical information about the vascular lesion

  19. Post-mortem CT-coronary angiography

    DEFF Research Database (Denmark)

    Pøhlsgaard, Camilla; Leth, Peter Mygind

    2007-01-01

    post-mortem coronary angiography and computerized tomography.  We describe how to prepare and inject the contrast medium, and how to establish a CT-protocol that optimizes spatial resolution, low contrast resolution and noise level. Testing of the method on 6 hearts, showed that the lumen...

  20. Intraarterial tolazoline in angiography of the foot

    International Nuclear Information System (INIS)

    Neubauer, B.

    1978-01-01

    Foot angiography was performed in 32 diabetic patients with and without intraarterial injection of tolazoline (Priscoline). The angiographic quality was improved with tolazoline, manifested as an increased flow rate with acceleration of the arteriovenous transit time, a higher incidence of complete arterial filling with contrast medium in clinically important regions, and considerably longer arterial segments demonstrated within defined regions of measurement. (Auth.)

  1. Angiography and angiotherapy of gastrointestinal tract bleeding

    Energy Technology Data Exchange (ETDEWEB)

    Soerensen, R.; Grassot, A.; Souchon, R.

    1982-03-01

    In selected patients with upper and lower gastrointestinal hemorrhage there is an indication for angiography. Vasoconstrictive drugs or embolization materials can be submitted through the catheter to stop the hemorrhage (angiotherapy). 81 patients were diagnosed by this method. Treatment through the angiographic catheter followed the diagnostic procedure in 41 cases. The hemorrhage was controlled in 36 patients.

  2. Digital subtraction angiography: first 900 cases

    International Nuclear Information System (INIS)

    Rodgers, H.

    1984-01-01

    The diagnostic technique of digital subtraction angiography (DSA) is briefly outlined. The operational and technical experiences with a DR-960 DSA system used in the examination of the first 900 cases at St. Thomas' Hospital, London are described. (U.K.)

  3. 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.)

  4. Two new contrast media in coronary angiography

    International Nuclear Information System (INIS)

    Selin, K.; Bjoerk, L.

    1983-01-01

    Amipaque, ioxaglic acid and Isopaque Coronar 300 were compared in a double blind investigation of coronary angiography in patients with ischemic heart disease. Amipaque affected systolic blood pressure and ECG less than the other contrast media. Ioxaglic acid appeared to give more ST and T changes than Isopaque Coronar. (Auth.)

  5. 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.)

  6. 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