伴皮层下梗死和白质脑病的常染色体显性遗传性脑动脉病的MRI表现

目的 探讨伴皮层下梗死和白质脑病的常染色体显性遗传性脑动脉病(CADASIL)的常规MRI扫描及功能成像特征。方法 回顾性分析10例经基因检测诊断为CADASIL的患者临床及MR检查资料。其中,10例均接受常规MRI平扫(4例平扫+增强扫描),8例接受DWI,4例接受磁敏感加权成像(ESWAN),3例接受扩散峰度成像(DKI),3例接受三维动脉自旋标记(ASL)检查,2例接受单体素MRS检查。结果 常规MRI:双侧额叶及外囊受累10例,颞叶、放射冠及基底节受累9例,颞极受累8例,枕叶及顶叶受累8例,脑干受累6例,胼胝体异常改变4例,表现为对称性的长T1长T2信号;其中4例MRI增强扫描均未见强化。DWI:8例中5例可见多发异常增高信号。ESWAN:4例中1例可见右侧豆状核、右侧岛叶、左侧丘脑、左侧颞叶皮层下多发点状低信号。DKI:均见MR平扫所示脑白质信号增高区MK值异常增高。ASL:均见MR平扫所示脑白质信号增高区脑血流量下降。MRS:脑白质高信号区N-乙酰天门冬氨酸(NAA)峰下降,乳酸(Lac)峰可见。结论 CADASIL的MR表现具有一定特征性,以皮层下、颞极、外囊、胼胝体、脑干受累为主。MR功能成像有助于定性诊断。

MRI findings of cerebral autosomal dominant arteriopathy with subcortical infarcts and leucoencephalopathy

Objective To investigate the conventional and functional MRI findings of cerebral autosomal dominant arteriopathy with subcortical infarcts and leucoencephalopathy (CADASIL). Methods Clinical and MRI data of totally 10 patients with CADASIL were retrospectively analyzed. All of 10 cases underwent conventional MRI plan scan, including 4 of them underwent plan scan and enhanced scan. And there were 8 cases underwent DWI, 4 cases underwent enhanced gradient echo T2 star weighted angiography (ESWAN), 3 cases underwent diffusion kurtosis imaging (DKI), 3 cases underwent arterial spin labeling (ASL) scan and 2 cases underwent MRS. Results Conventional MRI: CADASIL lesions manifested as symmetric abnormal signals involved bilateral frontal lobe and external capsule in 10 cases, temporal lobe, corona radiate and basal ganglia in 9 cases, temporal pole in 8 cases, occipital lobe and parietal lobe in 8 cases, brain stem in 6 cases and callosum in 4 cases. No enhancement was found in all 4 cases underwent conventional enhanced scan. DWI: Abnormal high signals were found in totally 5 of 8 cases. ESWAN: Multiple plaguliform low signals of right lentiform nucleus, right lobus insularis, left thalamus and subcortex white matter of left temporal lobe were found in 1 of 4 cases. DKI: The mean kurtosis (MK) was increased in white matter of hyperintensities on conventional MRI plan scan. ASL: The cerebral blood flow was decreased in white matter of hyperintensities on conventional MRI plan scan. MRS: The peak of N-acetylaspartate (NAA) in lesion foci was descend. And the lactic acid (Lac) peak was found. Conclusion MRI findings of CADASIL are characteristic. The lesions mainly involve subcortical structure, temporal pole, external capsule, callosum and brain stem. The functional MRI is helpful for qualitative diagnosis.