胼胝体变性的CT和MRI分析

MarchiafavaBignami Disease: Analysis of CT and MRI Findings

目的：分析胼胝体变性的ＣＴ和ＭＲＩ征象。材料与方法：４例胼胝体变性中，３例为急性发病，１例呈慢性过程。４例均行头颅ＣＴ扫描，２例行ＭＲＩ检查，其中１例同时行ＭＲＩ增强扫描。结果：２例ＣＴ示胼胝体膝部和压部呈片状低密度病变，２例病变仅见于膝部。病变的膝部（３例）和压部（２例）呈膨胀性改变，其中１例发病１６天后，ＭＲＩ平扫和强化未见膨胀性改变和异常强化。结论：（１）ＣＴ和ＭＲＩ是诊断胼胝体变性的有效方法，ＭＲＩ显示胼胝体更全面准确，特别是体部的显示；（２）胼胝体变性ＣＴ主要表现是片状低密度灶，急性发病者以膝部和压部常见，可见膨胀性改变，以膝部尤著；（３）晚期胼胝体病变区萎缩，ＭＲＩ表现为胼胝体中层带状低信号（Ｔ１ＷＩ），无强化。

Objective: To analyze the CT and MRI findings of MarchiafavaBignami disease. Materials and Methods:The clinical features of 4 cases (3 acute form and 1 chronic form) were correlated with the findings on CT (n=4) and MRI (n=2). Results:CT revealed a large lowdensity area in genu and splenium (n=2) or in genu only (n=2). Expansion of the affected genu (n=3) and splenium (n=2) was observed in the early stage. The enlargement and abnormal enhancement of genu in one patient could not demonstrated on both plain and contrastenhanced MRI performed 16 days after onset.Conclusion: (1) Both CT and MRI are effective modalities for diagnosing MarchiafavaBignami disease. MRI shows the corpus callosum, especially its body, more clearly. (2) The main feature of MarchiafavaBignami disease on CT is a lowdensity area. In acute form, enlargement of the splenium, and particularly of the genu, is commonly seen. (3) In the late stage, the lesion becomes atrophied, and abnormal bandshaped low signal zone without enhancement is seen in the middle layer of corpus callosum on T1WI.