腦膜瘤的電腦斷層攝影診斷

Computed Tomographic Findings of Meningiomas

衛優遊(Yau-Yau Wai) ； 黃國茂(Kou-Mou Huang)

《中華放射線醫學雜誌》 6卷3期 (1981/09) Pp. 216-224

摘要

腦膜瘤在電腦斷層攝影有頗為特徵性的形像。在無對比劑常規檢查，它的密度比周圍正常腦組織稍高或者相同。經靜脈注射對比劑後，整個腫瘤均勻的增加密度。腫瘤的界限很清楚。形狀呈圓型或呈小葉狀。腫瘤內時有鈣化。腫瘤的周圍，常有一圈低密度，經注射對比劑後不增加密度的地方。這些特殊的CT形像，和腦膜瘤發生的特殊位置，診斷率相當高。但腦膜瘤的CT表現也有不尋常的時候。若能認識比較常見的不尋常CT形像，對診斷幫忙很大。由於CT的迅速、安全和正確性，可以做為腦膜瘤的第一線檢查工具。但是，在須要手術切除的病例，腦血管攝影檢查是不可缺少的。

並列摘要

The CT scans of 34 proven meningiomas were reviewed in the Department of Diagnostic radiology of Chang Gung Memorial Hospital. They present rather characteristic findings. On the unenhanced CT scans, the tumors appear homogeneous, either slightly high density or isodensity areas with well defmed round or lobulated bonders. After contrast medium injection, the whole tumor increased in density homogeneously. In 64% of the meningiomas, there were a zone of low density surrounding the tumor. Calcifications were occasionally found in the tumor. These characteristic features associated with superficial location of the tumor, it is easy to make an accurate diagnosis of meningioma using CT scans. However, meningioma can produce atypical images. Features such as irregular areas of non.enhanced low density within the tumor or irregularity of tumor edges are reasons for mis-diagnosis. Cerebral angiography sometimes gives some information to the atypical CT images. The reverse is often true: CT scan may occasionally demonstrate a typical meningioma when the angiographi findings are atypical. Since there was no relationship between the degree of enhancement on CT scan and the amount of vascularity as estimated by the surgeon or histology. So, if CT scan is performed first, angiography must follow to demonstrate the blood supply to the tumor and the surrounding vascular anatomy. If angiography is carried out first, CT is still helpful in better definging the size of the tumor. Further more, there was no definite correlation betweeen the CT picture and the histologic pattern of the meningiomas.