Current State-of-the-Art 1.5 T and 3 T Extracranial Carotid Contrast-Enhanced Magnetic Resonance Angiography
ABSTRACT Recent advances in magnetic resonance (MR) hardware and software have improved the resolution and spatial coverage of head and neck first-pass contrast-enhanced (CE) MR angiography. Despite these improvements, high-quality submillimeter-resolution 1.5 T and 3 T carotid CE MR angiography is not consistently available in the general radiology practice. This article reviews the important imaging parameters and potential pitfalls that affect carotid CE MR angiography image quality, and the dose and timing of the gadolinium-based contrast agent, and summarizes vendor-specific protocols for high-quality submillimeter-resolution carotid CE MR angiography at 1.5 and 3 T.
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ABSTRACT: High field MRI operating at 3 T is increasingly being used in the field of neuroradiology on the grounds that higher magnetic field strength should theoretically lead to a higher diagnostic accuracy in the diagnosis of several disease entities. This Editorial discusses the exhaustive review by Wardlaw and colleagues of research comparing 3 T MRI with 1.5 T MRI in the field of neuroradiology. Interestingly, the authors found no convincing evidence of improved image quality, diagnostic accuracy, or reduced total examination times using 3 T MRI instead of 1.5 T MRI. These findings are highly relevant since a new generation of high field MRI systems operating at 7 T has recently been introduced. Key Points • Higher magnetic field strengths do not necessarily lead to a better diagnostic accuracy. • Disadvantages of high field MR systems have to be considered in clinical practice. • Higher field strengths are needed for functional imaging, spectroscopy, etc. • Disappointingly there are few direct comparisons of 1.5 and 3 T MRI. • Whether the next high field MR generation (7 T) will improve diagnostic accuracy has to be investigated.European Radiology 07/2012; 22(11):2304-6. DOI:10.1007/s00330-012-2552-9 · 4.34 Impact Factor
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ABSTRACT: Purpose: We evaluated the safety of gadopentetate dimeglumine (Gd-DTPA), the first contrast agent for magnetic resonance imaging, using pharmacovigilance data for spontaneously reported adverse events (AEs) after 120 million cumulative administrations worldwide. Methods: We analyzed spontaneously reported AEs for Gd-DTPA for pre-specified time periods between 1988 and 2011. Results: Since the market introduction of Gd-DTPA in 1988, its global utilization reached 120 million cumulative administrations in 2011, more than 80% of which was by the USA, countries in the European Union (EU), and Japan. The global AE reporting rate was 21.2 in 100,000 administrations in 1988 and 14.4 in 100,000 administrations by 2011. Regional differences included higher reporting rates in the USA and Japan, and reporting rates lower than global rates in the EU. The reported rate of global serious AEs changed from 1.4 in 100,000 administrations in 1988 to 4.0 in 100,000 administrations in 2011. The highest number of reports of nephrogenic systemic fibrosis (NSF) was received from 2006 to 2008. Since 2009, no report of a current onset of NSF has been received. The reduced report rate of NSF may be due to increased awareness about the use of gadolinium-based contrast agents (GBCAs). Conclusion: After more than 120 million cumulative administrations, Gd-DTPA is a widely used GBCA that shows a consistently low and stable incidence of AEs.Magnetic Resonance in Medical Sciences 10/2013; 12(4). DOI:10.2463/mrms.2013-0020 · 1.04 Impact Factor
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ABSTRACT: Background Comprehensive assessment of pediatric congenital heart disease (CHD) at any field strength mandates evaluation of both vascular and dynamic cardiac anatomy for which diagnostic quality contrast-enhanced magnetic resonance angiography (CEMRA) and cardiac cine are crucial. Objective To determine whether high-resolution (HR) CEMRA and steady-state free precession (SSFP) cine can be performed reliably at 3.0 T in children with CHD and to compare the image quality to similar techniques performed at 1.5 T. Materials and methods Twenty-eight patients with a median age of 5 months and average weight 9.0 ± 7.8 kg with suspected or known CHD were evaluated at 3.0 T. SSFP cine (n = 86 series) and HR-CEMRA (n = 414 named vascular segments) were performed and images were scored for image quality and artifacts. The findings were compared to those of 28 patients with CHD of similar weight who were evaluated at 1.5 T. Results Overall image quality on HR-CEMRA was rated as excellent or good in 96% (397/414) of vascular segments at 3.0 T (k = 0.49) and in 94% (349/371) of vascular segments at 1.5 T (k = 0.36). Overall image quality of SSFP was rated excellent or good in 91% (78/86) of cine series at 3.0 T (k = 0.55) and in 81% (87/108) at 1.5 T (k = 0.47). Off-resonance artifact was common at both field strengths, varied over the cardiac cycle and was more prevalent at 3.0 T. At 3.0 T, off-resonance dark band artifact on SSFP cine was absent in 3% (3/86), mild in 69% (59/86), moderate in 27% (23/86) and severe in 1% (1/86) of images; at 1.5 T, dark band artifact was absent in 16% (17/108), mild in 69% (75/108), moderate in 12% (13/108) and severe in 3% (3/108) of cine images. The signal-to-noise ratio and contrast-to-noise ratio of both SSFP cine and HR-CEMRA images were significantly higher at 3.0 T than at 1.5 T (PPediatric Radiology 08/2014; 45(1). DOI:10.1007/s00247-014-3093-y · 1.65 Impact Factor