橄榄脑桥小脑萎缩的磁共振诊断

目的探讨橄榄脑桥小脑萎缩（OPCA）的MRI表现特点，提高对OPCA的认识和早期诊断水平。方法回顾性分析15例OPCA磁共振成像表现。MRI成像采用SE序列，平扫T1wI、T2WI，轴位、冠状位、矢状位成像。结果OPCA的MRI表现有：（1）脑干萎缩变细，以桥脑前后径变小为著，本组15例患者均有此表现；（2）小脑体积变小，小脑沟、裂增宽、加深，半球小叶变细，小脑横径增宽，脑回细，14例为两侧小脑半球对称性缩小，1例为非对称性萎缩，左侧小脑左叶萎缩更明显；（3）15例患者均有四脑室扩大，桥前池、延髓前池增宽。（4）其他表现：3例患者有皮层下多发点状长T1长T2腔隙性脑梗塞；5例患者有大脑皮层萎缩，为轻度萎缩，萎缩程度明显轻于小脑、桥脑。结论OPCA的MRI表现具有特征性，是确诊本病的最佳检查方法。

Clinical magnetic resonance imaging diagnosis of olivopontocerebellar atrophy

Objective To study magnetic resonance imaging（MRI） features of olivopontocerebellar atrophy （OPCA） so that we can elevate recognition of the disease, which is helpful for the early stage diagnosis. Methods MRI findings of fifteen cases of OPCA were studied retrospectively. The sequences included T1WI of spin echo and T2WI of tuber spin echo onaxial, oronal and saittal. Results The main findings of OPCA were showed as the following （1）brain stem encephal atrophy and turns thin, the form of the pons changed more obviously,which can be found in whole group of fifteen examples.（2）the volumes of cerebellum turns small, the anfractuosity and schizencephaly of cerebellum became deep, the diameter transversa of cerebellum enlarged, cerebral convolution became small Among this group, fourteen examples were atrophic symmetrically for two sides of cerebellum, and one example atrophic unsymetrically. （3）the fourth ventricle enlarged, the cisterns in front of pons varolii and bulb widened, which could find in all fifteen cases. （4）other features： severalsubcortical lacunar infarctions could find in three cases, and five cases found pallium atrophy, which was less serve than cerebellum and bridge of Varolius were. Conclusion MR findings of OPCA has characteristic features. MRI is the best imaging examination for OPCA diagnosis.