Department of Neuroradiology, University Medical Center Göttingen, Göttingen, Germany.
Department of Neuroradiology, University Medical Center Göttingen, Göttingen, Germany.
Eur J Radiol. 2021 Jun;139:109677. doi: 10.1016/j.ejrad.2021.109677. Epub 2021 Mar 26.
Diffusion-weighted imaging in stimulated echo acquisition mode (STEAM-DWI) is an interesting alternative with less susceptibility artifacts compared to the most commonly used diffusion-weighted echo-planar imaging (EPI-DWI). Sensitivity and specificity of a novel STEAM-DWI, described by Merrem et al. 2017 [1], were assessed in patients with ischemic stroke.
EPI- and STEAM-DWIs were performed in patients with suspected subacute stroke between 01 July 2019 and 30 June 2020 using 3-T MRI. Three neuroradiologists independently and separately rated STEAM-DWI images with respect to (i) signs of an acute/subacute stroke, (ii) the number, size and localization of infarctions and, (iii) the presence of artifacts.
In 55 (23 right, 23 left, 9 both hemispheres) of 85 patients a subacute stroke was confirmed using EPI-DWI. The cerebral vascular territories were affected as follows: anterior cerebral artery 8 %, middle cerebral artery 48 %, posterior cerebral artery 27 %, brainstem 7 %, cerebellum 10 %. In 53 of 55 (96 %) cases the stroke was detected by usage of STEAM-DWI, in 35 of 37 patients microembolic events were noticed (95 %). Results showed a sensitivity and specificity of 100 % (70/70) for major infarcts (>9 mm² in-plane) and a sensitivity of up to 94 % (121/129) for detecting subacute microembolic lesions. No susceptibility artifacts were noticed in STEAM-DWI.
Compared to standard EPI-DWI, STEAM-DWI offers a more robust alternative for diagnosing subacute strokes in areas affected by susceptibility artifacts.
与最常用的扩散加权回波平面成像（EPI-DWI）相比，STEAM-DWI 具有更少的磁化率伪影，是一种很有前途的替代方法。2017 年 Merrem 等人描述的新型 STEAM-DWI 的敏感性和特异性在疑似缺血性脑卒中患者中进行了评估。
2019 年 7 月 1 日至 2020 年 6 月 30 日期间，使用 3T MRI 在疑似亚急性脑卒中患者中进行 EPI 和 STEAM-DWI。三位神经放射科医生独立地分别对 STEAM-DWI 图像进行评估，内容包括（i）急性/亚急性脑卒中的征象，（ii）梗死的数量、大小和定位，（iii）伪影的存在。
在 85 例患者中，有 55 例（右侧 23 例，左侧 23 例，双侧 9 例）通过 EPI-DWI 确诊为亚急性脑卒中。受累的脑血供区域如下：大脑前动脉 8%，大脑中动脉 48%，大脑后动脉 27%，脑干 7%，小脑 10%。在 55 例患者中，53 例（96%）患者通过 STEAM-DWI 检测到脑卒中，37 例患者中（95%）检测到微栓塞事件。结果显示，对于大于 9mm²的大面积梗死（96%），STEAM-DWI 的敏感性和特异性均为 100%（70/70），对于检测亚急性微栓塞病变的敏感性高达 94%（121/129）。在 STEAM-DWI 中未发现磁化率伪影。
与标准的 EPI-DWI 相比，STEAM-DWI 为诊断受磁化率伪影影响的亚急性脑卒中提供了一种更可靠的替代方法。
