亚急性脑梗塞MR扩散张量的评价

目的　评价MR扩散张量 (DTI)中各向同性成像、表观扩散系数 (ADC)图像、部分各向异性 (FA)图像、各向异性体积比 (VR)图像在诊断亚急性脑梗塞中的作用。方法　随机选取 13个亚急性脑梗塞患者 (共 17个病灶 ) ,利用扩散张量成像 (DTI)、扩散加权成像 (DWI)、T2 加权成像 (T2 WI)FSE序列等技术进行头颅MR扫描 ,并运用原始数据重建出ADC、FA、VR图像。结果　各向同性成像、ADC、FA、VR、DWI、T2 WI均能不同程度地检测出病灶 ,其中各向同性成像技术检测出所有的梗塞病灶 ;而ADC图像由于存在假阴性期 ,所以对部分病灶未能检出。结论　各向同性成像技术能更好的检测出亚急性脑梗塞 ,是各向同性成像、ADC、FA、VR、DWI和T2 WI中最敏感的方法

Assessment of Diffusion Tensor Imaging in Subacute Stroke

Objective To evaluate diffusion tensor imaging (DTI), including isotropic imaging, apparent diffusion coefficient (ADC), fractional anisotropy (FA) and volume ratio (VR), in the diagnosis of subacute stroke. Methods Thirteen patients (seventeen focuses) were scanned by diffusion tensor, diffusion and T 2 weighted FSE pulse sequences, and used the original data were used to reconstruct ADC, FA and VR maps. Results The sensitivities of isotropic imaging, ADC map, FA map, VR map, diffusion weighted imaging and T 2 weighted imaging for the diagnosis of subacute stroke were different. The isotropic imaging was the most sensitive, which could detect all of the focuses. ADC map could not find some lesions, as there was a false negative phase in ADC map. Conclusion Subacute stroke is better shown on isotropic imaging than on ADC map, FA map, VR map, DWI and T 2WI.