Topics in magnetic resonance imaging : TMRI
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Top Magn Reson Imaging · Apr 2007
ReviewWhole-body contrast-enhanced magnetic resonance angiography: new advances at 3.0 T.
During the past decade, technical improvements and numerous advances in scanner hardware and software have significantly improved image quality, speed, and reliability of 3-dimensional (3-D) contrast-enhanced magnetic resonance angiography (CE-MRA). The accuracy of CE-MRA is now comparable with that of computed tomography angiography or even conventional catheter angiography. Peripheral vascular disease (PVD) accounts for 50,000 to 60,000 cases of percutaneous transluminal angioplasty and for about 100,000 cases of amputation annually in the United States. ⋯ The lack of ionizing radiation and the use of contrast agent with relatively small potential nephrotoxicity in population of PVD with high prevalence of renal impairment are the appealing features for broad acceptance of CE-MRA in initial diagnosis and repeated follow-up studies of patients with PVD. The minimum anatomical coverage for evaluation of PVD comprises the aortic bifurcation to the ankles; however, because of the systemic nature of atherosclerosis hypertension, renal or cerebrovascular disease frequently coexist. Thus, many clinicians regard evaluation of the whole-body arterial vasculature as desirable.
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Top Magn Reson Imaging · Apr 2007
ReviewHigh-field-strength magnetic resonance: potential and limits.
To expatiate on the possible advantages and disadvantages of high magnetic field strengths for magnetic resonance imaging and, in particular, for magnetic resonance angiography. ⋯ The drive toward higher field strengths, both for the purpose of fundamental research and for clinical diagnostic imaging, is likely to continue. New applications using the unique properties of high field strength will almost certainly emerge as researchers gain more experience. The ultimate limiting factor is likely to be the physiological effects at high field strengths. However, this limit seems to lie at field strengths higher than 7 T because early experience shows good tolerance of 7 T examinations.