Schaefer Pamela W, Hunter George J, He Julian, Hamberg Leena M, Sorensen A Gregory, Schwamm Lee H, Koroshetz Walter J, Gonzalez R Gilberto
Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA.
AJNR Am J Neuroradiol. 2002 Nov-Dec;23(10):1785-94.
Diffusion and perfusion MR imaging have proved useful in the assessment of acute stroke. We evaluated the utility of these techniques in detecting acute ischemic infarction and in predicting final infarct size.
Diffusion and hemodynamic images were obtained in 134 patients within a mean of 12.3 hours of onset of acute ischemic stroke symptoms. We retrospectively reviewed patient radiology reports to determine the presence or absence of lesion identification on initial diffusion- (DW) and perfusion-weighted (PW) images. Radiologists were not blinded to the initial clinical assessment. For determination of sensitivity and specificity, the final discharge diagnosis was used as the criterion standard. Neurologists were not blinded to the DW or PW imaging findings. In 81 patients, acute lesions were compared with final infarct volumes.
Sensitivities of DW imaging and cerebral blood volume (CBV), cerebral blood flow (CBF), and mean transit time (MTT) perfusion parameters were 94%, 74%, 84%, and 84%, respectively. Specificities of DW imaging, CBV, CBF, and MTT were 96%, 100%, 96%, and 96%, respectively. Results were similar in 93 patients imaged within 12 hours. In 81 patients with follow-up, regression analysis yielded r(2) = 0.9, slope = 1.24 for DW imaging; r(2) = 0.84, slope = 1.22 for CBV; r(2) = 0.35, slope = 0.44 for CBF; and r(2) = 0.22, slope = 0.32 for MTT, versus follow-up volume. A DW-CBV mismatch predicted additional lesion growth, whereas DW-CBF and DW-MTT mismatches did not. Results were similar in 60 patients imaged within 12 hours.
Diffusion and hemodynamic images are sensitive and specific for detecting acute infarction. DW imaging and CBV best predict final infarct volume. DW-CBV mismatch predicts lesion growth into the CBV abnormality. CBF and MTT help identify additional tissue with altered perfusion but have lower correlation with final volume.
扩散加权磁共振成像（DW-MRI）和灌注加权磁共振成像已被证明在急性脑卒中评估中很有用。我们评估了这些技术在检测急性缺血性梗死及预测最终梗死体积方面的效用。
对134例急性缺血性卒中症状发作后平均12.3小时内的患者进行了扩散加权成像和血流动力学成像。我们回顾性地查阅了患者的放射学报告，以确定在初始扩散加权（DW）和灌注加权（PW）图像上是否存在病变。放射科医生知晓初始临床评估情况。为确定敏感性和特异性，最终出院诊断被用作标准参照。神经科医生知晓DW或PW成像结果。对81例患者的急性病变与最终梗死体积进行了比较。
DW成像、脑血容量（CBV）、脑血流量（CBF）和平均通过时间（MTT）灌注参数的敏感性分别为94%、74%、84%和84%。DW成像、CBV、CBF和MTT的特异性分别为96%、100%、96%和96%。在症状发作12小时内成像的93例患者中，结果相似。在81例接受随访的患者中，回归分析得出，与随访体积相比，DW成像的r² = 0.9，斜率 = 1.24；CBV的r² = 0.84，斜率 = 1.22；CBF的r² = 0.35，斜率 = 0.44；MTT的r² = 0.22，斜率 = 0.32。DW-CBV不匹配预示着会有额外的病变生长，而DW-CBF和DW-MTT不匹配则不然。在症状发作12小时内成像的60例患者中，结果相似。
扩散加权成像和血流动力学成像在检测急性梗死方面具有敏感性和特异性。DW成像和CBV对最终梗死体积的预测效果最佳。DW-CBV不匹配预示着病变会扩展至CBV异常区域。CBF和MTT有助于识别灌注改变的其他组织，但与最终体积的相关性较低。
