MR imaging at very high field (3.0 T) is a significant new clinical tool in the modern neuroradiological armamentarium. In this report, we summarize our 40-month experience in performing clinical neuroradiological examinations at 3.0 T and review the relevant technical issues. We report on these issues and, where appropriate, their solutions. Issues examined include: increased SNR, larger chemical shifts, additional problems associated with installation of these scanners, challenges in designing and obtaining appropriate clinical imaging coils, greater acoustic noise, increased power deposition, changes in relaxation rates and susceptibility effects, and issues surrounding the safety and compatibility of implanted devices. Some of the these technical factors are advantageous (eg, increased signal-to-noise ratio), some are detrimental (eg, installation, coil design and development, acoustic noise, power deposition, device compatibility, and safety), and a few have both benefits and disadvantages (eg, changes in relaxation, chemical shift, and susceptibility). Fortunately solutions have been developed or are currently under development, by us and by others, for nearly all of these challenges. A short series of 1.5 T and 3.0 T patient images are also presented to illustrate the potential diagnostic benefits of scanning at higher field strengths. In summary, by paying appropriate attention to the discussed technical issues, high-quality neuro-imaging of patients is possible at 3.0 T.

on behalf of the PREDICT/Sunnybrook ICH-CTA study group Background and Purpose-Reliable quantification of both intracerebral hemorrhage and intraventricular hemorrhage (IVH) volume is important for hemostatic trials. We evaluated the reliability of computer-assisted planimetric volume measurements of IVH. Methods-Computer-assisted planimetry was used to quantify IVH volume. Five raters measured IVH volumes, total (intracerebral hemorrhageϩIVH) volumes, and Graeb scores from 20 randomly selected computed tomography scans twice. Estimates of interrater and intrarater reliability were calculated and expressed as an intrarater correlation coefficient and an absolute minimum detectable difference. Results-Planimetric IVH volume analysis had excellent intra-and interrater agreement (intrarater correlation coefficient, 0.96 and 0.92, respectively), which was superior to the Graeb score (intrarater correlation coefficient, 0.88 and 0.83). Minimum detectable differences for intra-and interrater volumes were 12.1 mL and 17.3 mL, and were dependent on the total size of the hematoma; hematomas smaller than the median 43.8 mL had lower minimum detectable differences, whereas those larger than the median had higher minimum detectable differences. Planimetric total hemorrhage volume analysis had the best intra-and interrater agreement (intrarater correlation coefficient, 0.99 and 0.97, respectively). Key Words: intracerebral hemorrhage Ⅲ intraventricular hemorrhage Ⅲ planimetry H ematoma volume and intraventricular hemorrhage (IVH) are independent predictors of outcome following intracerebral hemorrhage (ICH). 1-2 Early ventricular rupture and subsequent autodecompression of parenchymal hematoma is common in ICH. 3 Ventricular decompression of ICH results in IVH expansion, which is also associated with poor outcome. 2 Given that hematoma expansion is a common surrogate outcome for ICH studies, 4 easy and accurate measurement of IVH and volume dynamics following ventricular rupture is relevant to hemostatic trials. In this study, we sought to evaluate the reliability of computer-assisted planimetric measurements for quantifying IVH volumes. Conclusions-Computer-assisted MethodsThe computer-assisted volume measurement software Quantomo (Cybertrial) 5 was used to quantify IVH volumes. Quantomo provides an interface that enables raters to guide segmentation algorithms with manual planimetric intervention to quantify volumes on computed tomography (CT) and magnetic resonance scans. Raters measured ICH and IVH volumes by selecting a hematoma and adjusting intensity thresholds, adding or removing regions to the computerselected region at their discretion, and manually drawing boundaries to separate IVH from ICH. CT scans of patients with both ICH and IVH were blindly and randomly selected from the ongoing PREDICT study. 6 Five raters (2 neurologists, 1 radiologist, 1 neuroradiologist, and 1 radiology trainee) measured IVH volumes, total (ICHϩIVH) volumes, and Graeb scores from 20 randomly selected CT scans twice, presented in a blind...

MR imaging at very high field (3.0 T) is a significant new clinical tool in the modern neuroradiological armamentarium. In this report, we summarize our 40-month experience in performing clinical neuroradiological examinations at 3.0 T and review the relevant technical issues. We report on these issues and, where appropriate, their solutions. Issues examined include: increased SNR, larger chemical shifts, additional problems associated with installation of these scanners, challenges in designing and obtaining appropriate clinical imaging coils, greater acoustic noise, increased power deposition, changes in relaxation rates and susceptibility effects, and issues surrounding the safety and compatibility of implanted devices. Some of the these technical factors are advantageous (eg, increased signal-to-noise ratio), some are detrimental (eg, installation, coil design and development, acoustic noise, power deposition, device compatibility, and safety), and a few have both benefits and disadvantages (eg, changes in relaxation, chemical shift, and susceptibility). Fortunately solutions have been developed or are currently under development, by us and by others, for nearly all of these challenges. A short series of 1.5 T and 3.0 T patient images are also presented to illustrate the potential diagnostic benefits of scanning at higher field strengths. In summary, by paying appropriate attention to the discussed technical issues, high-quality neuro-imaging of patients is possible at 3.0 T.