肥大性下橄榄核变性的MRI表现

目的 总结肥大性下橄榄核变性(hypertrophic olivary degeneration，HOD)的MRI特征.方法 搜集继发于脑干和小脑病变的HOD病例15例，原发病变位于脑干9例，其中血管畸形出血4例，高血压脑干出血2例，梗死2例，脑干挫伤1例；原发病变位于小脑6例，其中小脑半球出血4例，小脑第4脑室肿瘤术后1例，小脑转移瘤1例。15例均做了MR平扫，2例做了增强扫描。结果 HOD表现为延髓腹外侧局部体积稍增大(共6例)，T1WI表现为等或稍低信号(15例)，在T2WI为高信号(15例)。原发性病变导致中脑红核或桥脑被盖束受损者，发生同侧HOD(8例)；原发病变导致小脑齿状核受损者并引起对侧HOD(4例)，双侧中央被盖束受损(1例)或双侧小脑齿状核受累及者(2例)，发生双侧HOD。结论 MRI能非常清晰地显示下橄榄核的继发性变性病变，可以提高对该变性的认识，避免误诊的发生.

MRI appearance of hypertrophic olivary degeneration

Objective To analyze magnetic resonance imaging (MRI) characteristics of hypertrophic olivary degeneration(HOD) Methods Fifteen cases of HOD which were secondary to brain stem or cerebellar lesions were collected retrospectively There were nine cases with primary lesions located in brain stem, including arterial venous malformation (4 cases), hypertensive hemarrhage (2 cases),infarction (2 cases), and head trauma (1 case) Six cases with primary cerebellar lesions included hemarrhage (4 cases), tumor dissection (1 case), and cerebellar metastasis (1 case) There were 10 men and 5 women, aged from 22 to 71 years (mean 47 3 years) Results HOD was showed as enlargement of ventral lateral part of medulla (6 cases) and presented as iso or hypointensity on T 1weighted images and hyperintensity on T 2 weighted images HOD was located ipsilaterally with primary lesions when red nucleus or pontine central tegmental tract was involved (8 cases), while contralaterally to primary lesions when dentate nucleus was involved (4 cases) When both sides of central tegmental tract(1 case) or dentate nucleus (2 cases) were involved, HOD could be observed bilaterally Conclusion This specific degeneration occurring in inferior olivary nucleus could be demonstrated clearly with MRI, thus improving the knowledge to this degeneration and avoiding error in interpretation