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Setsuro Komiya - One of the best experts on this subject based on the ideXlab platform.
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Magnetic Resonance Angiography for vertebral artery evaluation in rheumatoid arthritis patients
Neurosurgery, 2010Co-Authors: Michihisa Zenmyo, Kosei Ijiri, Hiromi Sasaki, Harutoshi Sakakima, Eiji Taketomi, Ryusaku Nagayoshi, Takuya Yamamoto, Setsuro KomiyaAbstract:OBJECTIVE: To examine the radiological features of vertebral artery (VA) displacement/occlusion associated with rheumatoid arthritis (RA) spine using Magnetic Resonance Angiography. METHODS: Forty-seven RA patients with upper cervical lesions were evaluated for patency or abnormality of the VA by extracranial Magnetic Resonance Angiography, with comparison of findings with those of 46 healthy volunteers. RESULTS: VA occlusion occurred in 4 patients (8.5%) and VA stenosis in 9 patients (19.1%). Anomaly of the VA was also observed in 3 patients (6.4%). No occlusion or anomaly was found in healthy volunteers, but 1 case of stenosis was found. Severity of vertical subluxation was correlated with the presence of VA abnormality in RA patients. CONCLUSION: The incidence of VA abnormality was 34% in RA patients and 2% in healthy volunteers. Magnetic Resonance Angiography is useful for screening for abnormality of the entire VA.
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Magnetic Resonance Angiography for vertebral artery evaluation in rheumatoid arthritis patients.
Neurosurgery, 2010Co-Authors: Michihisa Zenmyo, Kosei Ijiri, Hiromi Sasaki, Harutoshi Sakakima, Eiji Taketomi, Ryusaku Nagayoshi, Takuya Yamamoto, Setsuro KomiyaAbstract:OBJECTIVE To examine the radiological features of vertebral artery (VA) displacement/occlusion associated with rheumatoid arthritis (RA) spine using Magnetic Resonance Angiography. METHODS Forty-seven RA patients with upper cervical lesions were evaluated for patency or abnormality of the VA by extracranial Magnetic Resonance Angiography, with comparison of findings with those of 46 healthy volunteers. RESULTS VA occlusion occurred in 4 patients (8.5%) and VA stenosis in 9 patients (19.1%). Anomaly of the VA was also observed in 3 patients (6.4%). No occlusion or anomaly was found in healthy volunteers, but 1 case of stenosis was found. Severity of vertical subluxation was correlated with the presence of VA abnormality in RA patients. CONCLUSION The incidence of VA abnormality was 34% in RA patients and 2% in healthy volunteers. Magnetic Resonance Angiography is useful for screening for abnormality of the entire VA.
James F. M. Meaney - One of the best experts on this subject based on the ideXlab platform.
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Magnetic Resonance Angiography of the head and neck vessels.
European radiology, 2007Co-Authors: Marco Essig, Konstantin Nikolaou, James F. M. MeaneyAbstract:Abstract Stroke, a major cause of death and disability in the developed world, is usually caused by atherosclerosis, most commonly an arterioocclusive lesion at the carotid bifurcation. Numerous multicentre trials have demonstrated that carotid endarterectomy can reduce the risk of stroke in these patients. However, because of the morbidity of catheter Angiography coupled with the risks of surgery, the benefits outweigh the risks of surgery only for those with >70% carotid artery stenosis. The gold standard method for assessing the degree of stenosis is catheter-directed cerebral digital subtraction Angiography; however, this is associated with a small but substantial stroke risk in addition to inherent risks associated with use of ionizing radiation and nephrotoxic contrast agents. The requirement for alternative imaging techniques that do not contribute to morbidity is ideally met by contrast-enhanced Magnetic Resonance Angiography, which eliminates the need for direct catheterization and therefore eliminates stroke risk associated with a patient work-up. Advances in contrast-enhanced Magnetic Resonance Angiography technology have led to a technique that achieves the goals of high spatial and temporal resolution required for stenosis assessment and streamlining of patients along surgical or medical lines. With the advent of a novel contrast agent, gadofosveset trisodium (Vasovist, Bayer Schering Pharma AG, Berlin, Germany), which has a high relaxivity and an extended imaging time, improved diagnosis of carotid artery stenoses with Magnetic Resonance Angiography can be expected. Gadofosveset trisodium facilitates improved first-pass imaging and also delays steady-state imaging with one injection. Although developed for vascular imaging, gadofosveset trisodium may also allow assessment of brain vascularity, blood-brain barrier breakdown and neurodegenerative disease.
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Use of Magnetic Resonance Angiography to select candidates with recently symptomatic carotid stenosis for surgery: systematic review
BMJ (Clinical research ed.), 2002Co-Authors: Marie E. Westwood, Steven Kelly, Elizabeth Berry, John Bamford, Michael J Gough, C. Mark Airey, James F. M. Meaney, Linda Davies, Cullingworth J, Michael A. SmithAbstract:Abstract Objective: To determine if sufficient evidence exists to support the use of Magnetic Resonance Angiography as a means of selecting patients with recently symptomatic high grade carotid stenosis for surgery. Design: Systematic review of published research on the diagnostic performance of Magnetic Resonance Angiography, 1990-9. Main outcome measures: Performance characteristics of diagnostic test. Results: 126 potentially relevant articles were identified, but many articles failed to examine the performance of Magnetic Resonance Angiography as a diagnostic test at the surgical decision thresholds used in major clinical trials on endarterectomy. 26 articles were included in a meta-analysis that showed a maximal joint sensitivity and specificity of 99% (95% confidence interval 98% to 100%) for identifying 70-99% stenosis and 90% (81% to 99%) for identifying 50-99% stenosis. Only four articles evaluated contrast enhanced Magnetic Resonance Angiography. Conclusions: Magnetic Resonance Angiography is accurate for selecting patients for carotid endarterectomy at the surgical decision thresholds established in the major endarterectomy trials, but the evidence is not very robust because of the heterogeneity of the studies included. Research is needed to determine the diagnostic performance of the most recent developments in Magnetic Resonance Angiography, including contrast enhanced techniques, as well as to assess the impact of Magnetic Resonance Angiography on surgical decision making and outcomes. What is already known on this topic Carotid endarterectomy for recently symptomatic carotid stenosis is beneficial in patients with 70-99% stenosis as measured by conventional Angiography It is not known whether the less invasive imaging technique of Magnetic Resonance Angiography can accurately identify patients who will benefit from surgery What this study adds Magnetic Resonance Angiography is highly sensitive and specific in diagnosing 70-99% carotid stenosis However, the studies on which this conclusion is based are of low quality and high heterogeneity
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Diagnosis of Pulmonary Embolism with Magnetic Resonance Angiography
The New England journal of medicine, 1997Co-Authors: James F. M. Meaney, Thomas L. Chenevert, John G. Weg, David B. Stafford-johnson, Brian H. Hamilton, Martin R. PrinceAbstract:Background Diagnosing pulmonary embolism may be difficult, because there is no reliable noninvasive imaging method. We compared a new noninvasive method, gadolinium-enhanced pulmonary Magnetic Resonance Angiography, with standard pulmonary Angiography for diagnosing pulmonary embolism. Methods A total of 30 consecutive patients with suspected pulmonary embolism underwent both standard pulmonary Angiography and Magnetic Resonance Angiography during the pulmonary arterial phase at the time of an intravenous bolus of gadolinium. All Magnetic Resonance images were reviewed for the presence or absence of pulmonary emboli by three independent reviewers who were unaware of the findings on standard angiograms. Results Pulmonary embolism was detected by standard pulmonary Angiography in 8 of the 30 patients in whom pulmonary embolism was suspected. All 5 lobar emboli and 16 of 17 segmental emboli identified on standard angiograms were also identified on Magnetic Resonance images. Two of the three reviewers reporte...
Christopher J. François - One of the best experts on this subject based on the ideXlab platform.
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Abdominal Magnetic Resonance Angiography.
Magnetic resonance imaging clinics of North America, 2020Co-Authors: Christopher J. FrançoisAbstract:MR imaging hardware and software improvements have led to new applications for contrast-enhanced and noncontrast-enhanced Magnetic Resonance Angiography in the abdomen and pelvis. Higher Magnetic field strength MR imaging scanners have greater signal-to-noise ratio and contrast-to-noise ratio, which is used to improve spatial resolution or temporal resolution for these techniques. New noncontrast-enhanced sequences offer high-resolution Magnetic Resonance Angiography without contrast and provide additional hemodynamic information. Magnetic Resonance Angiography is particularly well suited to imaging patients with chronic mesenteric ischemia, renal vascular disease, pelvic congestion syndrome, and vascular malformations.
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Pulmonary Vascular Disease Evaluation with Magnetic Resonance Angiography.
Radiologic clinics of North America, 2020Co-Authors: Bradley D. Allen, Mark L. Schiebler, Christopher J. FrançoisAbstract:Pulmonary vascular assessment commonly relies on computed tomography Angiography (CTA), but continued advances in Magnetic Resonance Angiography have allowed pulmonary Magnetic Resonance Angiography (pMRA) to become a reasonable alternative to CTA without exposing patients to ionizing radiation. pMRA allows the evaluation of pulmonary vascular anatomy, hemodynamic physiology, lung parenchymal perfusion, and (optionally) right and left ventricular function with a single examination. This article discusses pMRA techniques and artifacts; performance in commonly encountered pulmonary vascular diseases, specifically pulmonary embolism and pulmonary hypertension; and recent advances in both contrast-enhanced and noncontrast pMRA.
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Magnetic Resonance Angiography
Cardiac CT and MR for Adult Congenital Heart Disease, 2013Co-Authors: Christopher J. FrançoisAbstract:The clinical use of Magnetic Resonance Angiography (MRA) has rapidly expanded as technological advances in both hardware and imaging techniques overcome previous limitations. This is particularly true for imaging of patients with congenital heart disease (CHD), who are often younger and frequently require continued, lifelong imaging follow-up. In this chapter, we will review recent developments in contrast-enhanced (CE) MRA and non-contrast-enhanced (NCE) MRA techniques applicable to CHD.
Guillem Pons-lladó - One of the best experts on this subject based on the ideXlab platform.
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Morphologic Study of the Pulmonary Veins by Magnetic Resonance Angiography
Revista espanola de cardiologia, 2005Co-Authors: Francesc Carreras, Eva Guillaumet, Sandra Pujadas, Raúl López-salguero, Carme Ligero, Rubén Leta, Guillem Pons-lladóAbstract:Accurate knowledge of the anatomy of the pulmonary veins is important in clinical electrophysiology. In order to evaluate the usefulness of Magnetic Resonance Angiography for this purpose, we studied 17 unselected patients. All the pulmonary veins were visualized in each individual. The diameters of the ostia ranged between 9 mm and 22 mm. The cross-section of the ostium was elliptical in 35% of cases. In 14 patients (82%), the 4 veins each had independent drainage. In 2 patients (12%), there was an additional intermediate right vein and, in 1 patient (6%), both left veins had a common ostium. In 74% of patients, the right pulmonary veins had a short common trunk with early branching. This pattern was seen in only 10% of left veins. Magnetic Resonance Angiography using a contrast medium is an excellent technique for studying the anatomy of the pulmonary veins and for identifying variants. The resulting information is potentially useful for electrophysiologists.
T Thien - One of the best experts on this subject based on the ideXlab platform.
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Magnetic Resonance Angiography has a high reliability in the detection of renal artery stenosis.
American journal of hypertension, 1997Co-Authors: C T Postma, F B Joosten, G Rosenbusch, T ThienAbstract:In this prospective study we examined the value of Magnetic Resonance Angiography (MRA) in the imaging of the proximal renal arteries, with the main aim of detecting renal arterial stenosis, as compared with intraarterial digital subtraction Angiography. The study was done among a group of 38 hypertensive patients seen in the outpatient department of the department of medicine of our university hospital. In all patients a Magnetic Resonance Angiography and an intraarterial subtraction Angiography of the renal arteries was made, and the outcomes of the investigations were compared. Clinical and biochemical data of the patients also were analyzed in relation to the presence or absence of a stenosis. In one patient, MRA resulted in technical failure because of unsuspected claustrophobia. Of the remaining 37 patients, 14 had renal artery stenosis. Of 12 patients in whom the stenoses were >50% of luminal surface on intraarterial digital subtraction Angiography, eight were unilateral and four bilateral. All these stenoses were recognized by Magnetic Resonance Angiography. There was also one false positive result by Magnetic Resonance. Thus, for the identification of stenoses >50%, Magnetic Resonance has a sensitivity of 100% and a specificity of 96%. Of the 12 accessory renal arteries seen on digital subtraction Angiography, only three were identified by Magnetic Resonance Angiography. We conclude that Magnetic Resonance Angiography has great accuracy in depicting the main renal arteries and detecting clinically significant renal artery stenosis; however, the identification of accessory renal arteries is suboptimal and should be improved.