From the Department of Radiology (A.-L.C., C.R.M., M.L.L., R.F., M.G., E.E.S.), Seaman Family MR Research Centre (S.B., C.R.M., M.L.L., R.F., M.G., E.E.S.), Hotchkiss Brain Institute (R.F., M.G., E.E.S.), and Department of Clinical Neurosciences, University of Calgary, Calgary, Canada (E.E.S.).
Stroke. 2013 Oct;44(10):2782-6. doi: 10.1161/STROKEAHA.113.002267. Epub 2013 Aug 6.
We investigated the sensitivity and reliability of MRI susceptibility-weighted imaging (SWI) compared with routine MRI T2*-weighted gradient-recalled echo (GRE) for cerebral microbleed (CMB) detection.
We used data from a prospective study of cerebral amyloid angiopathy (n=9; mean age, 71±8.3) and healthy non-cerebral amyloid angiopathy controls (n=22; mean age, 68±6.3). Three raters (labeled 1, 2, and 3) independently interpreted the GRE and SWI sequences (using the phase-filtered magnitude image) blinded to clinical information.
In 9 cerebral amyloid angiopathy cases, the raters identified 1146 total CMBs on GRE and 1432 CMBs on SWI. In 22 healthy control subjects, the raters identified ≥1 CMBs in 6/22 on GRE (total 9 CMBs) and 5/22 on SWI (total 19 CMBs). Among cerebral amyloid angiopathy cases, the reliability between raters for CMB counts was good for SWI (intraclass correlation coefficient, 0.87) but only moderate for GRE (intraclass correlation coefficient, 0.52). In controls, agreement on the presence or absence of CMBs in controls was moderate to good on both SWI (κ coefficient ranged from 0.57 to 0.74 across the 3 combinations of rater pairs) and GRE (κ range, 0.31 to 0.70). A review of 114 hypointensities identified as possible CMBs indicated that increased detection and reliability on SWI was related to both increased contrast and higher resolution, allowing better discrimination of CMBs from the background and better anatomic differentiation from pial vessels.
SWI confers greater reliability as well as greater sensitivity for CMB detection compared with GRE, and should be the preferred sequence for quantifying CMB counts.
我们研究了 MRI 磁化率加权成像（SWI）与常规 MRI T2*-梯度回波（GRE）检测脑微出血（CMB）的敏感性和可靠性。
我们使用了一项脑淀粉样血管病（n=9；平均年龄 71±8.3 岁）和健康非脑淀粉样血管病对照（n=22；平均年龄 68±6.3 岁）前瞻性研究的数据。三名阅片者（标记为 1、2 和 3）独立解读 GRE 和 SWI 序列（使用相位滤波的幅度图像），对临床信息进行盲法解读。
在 9 例脑淀粉样血管病病例中，3 名阅片者在 GRE 上共发现 1146 个 CMB，在 SWI 上共发现 1432 个 CMB。在 22 例健康对照中，6/22 在 GRE 上发现≥1 个 CMB（共 9 个 CMB），5/22 在 SWI 上发现≥1 个 CMB（共 19 个 CMB）。在脑淀粉样血管病病例中，SWI 上 CMB 计数的阅片者间可靠性良好（组内相关系数，0.87），而 GRE 上的可靠性仅为中度（组内相关系数，0.52）。在对照中，SWI 上对 CMB 有无的判断一致性在中度到高度之间（3 名阅片者两两组合的 κ 系数范围为 0.57 至 0.74），GRE 上的判断一致性也在中度到高度之间（κ 范围为 0.31 至 0.70）。对 114 个被认为可能是 CMB 的低信号进行复查后表明，SWI 上 CMB 检测的敏感性和可靠性的提高与对比度和分辨率的提高有关，从而能更好地区分 CMB 与背景，更好地从脑膜血管中区分 CMB。
与 GRE 相比，SWI 不仅能提高 CMB 检测的敏感性，还能提高其可靠性，应该成为定量 CMB 计数的首选序列。
