Department of Radiology, University Medical Center Utrecht, the Netherlands.
AJNR Am J Neuroradiol. 2011 Jun-Jul;32(6):1043-9. doi: 10.3174/ajnr.A2450. Epub 2011 May 5.
The detection of microbleeds differs strongly between studies, due to differences in scan protocol. This study aims to compare the visualization of microbleeds with 3D T2*-weighted imaging at 1.5T with 3D dual-echo T2*-weighted imaging at 7T.
Thirty-four patients (29 male; mean age, 58 ± 12 years) with atherosclerotic disease from the Second Manifestations of ARTerial Disease study were included. 3D T2*-weighted imaging at 1.5T and dual-echo T2*-weighted imaging at 7T were done in all patients. The presence and number of definite microbleeds were recorded on minimal intensity projections. Inter- and intraobserver reliability was assessed with Cohen κ test and the ICC. The difference in presence and number of microbleeds was tested with the McNemar test and Wilcoxon signed rank test.
The interobserver ICC at 7T was 0.61 and the intraobserver ICC was 0.94, whereas at 1.5T the interobserver ICC was 0.50 and the intraobserver ICC was 0.59. Microbleeds were detected in significantly more patients on 7T (50%) than on 1.5T scans (21%) (P = .001). The number of microbleeds was also higher at 7T (median, 0.5; range, 0-5) than on 1.5T (median, 0.0; range, 0-6) (P = .002).
3D dual-echo T2*-weighted imaging at 7T results in better and more reliable detection of microbleeds compared with 3D T2*-weighted imaging at 1.5T.
由于扫描方案的差异，不同研究之间对微出血的检测结果差异很大。本研究旨在比较在 1.5T 上进行的 3D T2*-加权成像与在 7T 上进行的 3D 双回波 T2*-加权成像对微出血的显示效果。
共纳入 34 例动脉粥样硬化性疾病的 2 型糖尿病患者（29 例男性；平均年龄 58±12 岁），所有患者均进行了 1.5T 3D T2*-加权成像和 7T 双回波 T2*-加权成像。在最小强度投影图上记录明确微出血的存在和数量。采用 Cohen κ 检验和 ICC 评估观察者间和观察者内的可靠性。采用 McNemar 检验和 Wilcoxon 符号秩检验比较微出血的存在和数量差异。
7T 时观察者间 ICC 为 0.61，观察者内 ICC 为 0.94，而 1.5T 时观察者间 ICC 为 0.50，观察者内 ICC 为 0.59。7T 时可检测到微出血的患者比例显著高于 1.5T（50%比 21%，P=0.001）。7T 时微出血的数量也高于 1.5T（中位数 0.5；范围 0-5）（中位数 0.0；范围 0-6）（P=0.002）。
与 1.5T 3D T2*-加权成像相比，7T 3D 双回波 T2*-加权成像可更好、更可靠地检测微出血。
