桥脑中央髓鞘溶解症的MRI诊断

目的评价MR对桥脑中央髓鞘溶解症(centralpontinemyelinolysis,CPM)的诊断价值。方法收集病例8例。主要病史:肝病史、酗酒、电解质紊乱等。扫描设备siemesmagnetonvision1.5T超导MR,头线圈,TSE序列、FLAIR序列。MAGNETONPLUS螺旋CT扫描。2例在桥脑病灶处行MR单体素1H-MRS点解析波谱法(PRESS)检查。结果MRI显示8例全部有阳性发现,其中桥脑病灶8例,丘脑、尾状核头部、内囊等处异常信号6例,信号呈长T1长T2信号。病灶显示率:FLAIR为100%,T2W为85%,T1W为50%。1H-MRS示:NAA降低,Cho升高,NAA/Cr比值降低,Cho/Cr比值稍高。CT显示阳性5例,阴性3例,阳性病例中双侧基底节、桥脑出现斑片状低密度灶4例、桥脑低密度1例。结论MRI诊断价值明显优于CT,FLAIR序列对病灶显示尤为清楚,结合病史可明确诊断。1H-MRS无特异性,峰值可提示病灶部分组织学变化。

MRI of central pontine myelinolysis

Objective To evaluate the diagnostic value of magnetic resonance imaging in central pontine myelinolysis syndrome. Methods Eight cases suspected of CPM with previous history of hepatic diseases, alcohol abuse or serum electrolyte imbalance were stadied retrospectively. MRI and CT scanning were performed with Siemens plus CT and Magnetom Vision 1.5T. In two cases, single voxel 1H-MRS with PRESS sequence were performed in pontine area also. Results MRI revealed pontine lesions in all cases. In six cases, lesions in thalamus, head of caudate nucleus and internal capsule were noted also. All lesions were long T1 and long T2 signal on MR imagings. Sensitivity of FLAIR, T2W, T1W were 100%, 85% and 50% respectively. 1H-MRS revealed decrease of NAA and increase of Cho within lesions. Ratio of NAA/Cr was slightly decreased and Cho/Cr was increased slightly. CT showed hypointensity lesions in pontine area of 5 cases within which 4 cases accompanied by bilateral basal ganglion hypointensity lesions. Three cases were false negative on CT images. Conclusion MRI is better than CT in depicting lesions of CPM. Lesions can be displayed more clearly on FLAIR images than other sequences. Combined with clinical history, CPM can be diagnosed with MRI clearly. 1H-MRS reveals some metabolic changes within lesions but the specificity still need to be observed.