Roentgenologic Manifestations of Astrocytoma in Childhood and a Corelation with Histologic Grades

小孩顱內星狀膠質瘤之放射線學徵象與腫瘤惡性度相關性之評估

萬永亮(Yung-Liang Wan) ； 呂鎮中(Chun-Chung Lui) ； 李子瑜(Tze-Yu Lee) ； 蔡長晃(Chang-Huang Tsai) ； 蔡春泉(Chung-Chueng Tsai)

《中華放射線醫學雜誌》 12卷1期 (1987/03) Pp. 1-10

摘要

自1977年12月至1985年8月，在長庚醫院除了原發性腦幹瘤，共有33例經手術及病理證實之小孩顱內星狀膠質瘤，除了回顧患者年齡、腫瘤部位及惡性度，還分析了其手術前之放射線學檢查，包括28例腦部電腦斷層攝影(CT)及19例腦血管攝影，以探討其放射線學表徵與腫瘤惡性度之相關性。
33例中，天幕上者佔17例，其中52.9彩有囊腫，29.4形為惡性。天幕下者佔16例，其中75%有囊腫，僅12.5%的惡性。
注射對比劑前後之CT中，其放線線學之表徵，天幕上者較天幕下者變化多。所有無顯影增強(enhancement)之病灶為良性。所有惡性腫瘤，皆有明顯的顯影增強，幾乎所有小腦星狀膠質瘤，在注射對比劑前之CT為低密度且皆為良性，僅一例為高密度，後證實為惡性。而注射對比劑後CT中，2例毫無顯影增強者為良性。其餘良性腫瘤則有壁節(mural nodule)壁環(rim)或腫瘤實質部份之顯影增強。至於天幕上之星狀膠質瘤，除一例毫無顯影增強為良性腫瘤外，其注射對比劑前後之 CT表現為多樣性，對腫瘤之惡性度無依據可尋。除非壁環之顯影增強為花彩狀(garland-shaped)，通常此表示惡性瘤。
在腦血管攝影中，所有惡性星狀膠質瘤都顯現高血管性(hypervascularity)甚至動靜脈瘦管(arteriovenous shunt)。但此類血管攝影之表徵，亦可出現於良性小腦星狀膠質瘤或腦室膜下巨細胞星狀膠質瘤(subependymal giant cell astrocytoma)。
20例有囊之腫瘤中，其CT表徵如下：15%完全無顯影增強，50%有壁節，20%有壁環之顯影，15%兼有壁環之顯影與壁節。囊腫、壁節或壁環顯影非良性星狀膠質瘤所獨有。然而腫瘤若有鈣化一般多表示良性。

並列摘要

Excluding primary brain stem glioma, the radiographies of 33 cases of childhood intracranial astrocytoma were reviewed and analyzed to correlate with the histologic grades. The radiologic studies included computed tomography (CT) in 28 cases, and cerebral angiography in 19 cases.
In 33 cases, the ratio of supratentorial (ST) and infratentorial (IT) astrocytoma was 17:16, including 7 malignancy by a ratio of 5:2. Cysts were present in 75% of IT astrocytomas, and in 52.9% of ST lesions.
Both pre-and post-enhanced CT revealed much more variable manifestations in cases of ST than IT astrocytomas. All the non-enhanced tumor were low grade. The heterogeneous enhancement is not specific for malignancy. On CT of 20 cystic astrocytomas, there were no enhancement in 15%, only mural nodule in 50%, only rim enhancement in 20%, both rim enhancement and mural nodules in 15%. The presence of cysts, mural nodules or rim enhancement are not helpful in differentiating low and high grade tumors, unless there is garland-shaped rim enhancement which is an indicator sif malignancy-The presence of calcification highly suggests low grade lesions.
Hypervascularity, especially with early draining veins, suggest the tumor to be malignant, except in cases of subependymal giant cell or cerebellar astrocytoma.