Margain D, Peretti-Viton P, Arnaud O, Martini P, Salamon G
Service de Neuroradiologie, CHU Timone, Marseille, France.
J Neuroradiol. 1991;18(2):141-52.
Astrocytic tumours are frequent, accounting for nearly 50% of all brain tumours. They are divided into three groups: benign astrocytomas, anaplastic astrocytomas and malignant glioblastomas. The usual clinical manifestations of benign astrocytic tumours are epileptic seizures, whereas those of glioblastomas are rapidly progressing neurological deficits. These lesions show fairly characteristic neuroradiological features which have been largely studied. Injections of iodine-based or paramagnetic contrast media are important since they help in tumour grading: low-grade tumours are not enhanced, while glioblastomas are almost invariably enhanced. MRI seems to be indispensable for the study of astrocytic tumours: it provides an excellent anatomical analysis of the lesion during preoperative or pretherapeutic evaluation, and it is the only available method to confirm low-grade lesions that have passed unnoticed or have merely been suspected at CT. To avoid missing these tumours, every adult presenting with recent onset epileptic seizures should be explored by MRI using T2-weighted spin-echo sequences.
星形细胞瘤很常见，占所有脑肿瘤的近50%。它们分为三组：良性星形细胞瘤、间变性星形细胞瘤和恶性胶质母细胞瘤。良性星形细胞瘤的常见临床表现为癫痫发作，而胶质母细胞瘤的临床表现为迅速进展的神经功能缺损。这些病变具有相当典型的神经放射学特征，对此已有大量研究。注射碘基或顺磁性造影剂很重要，因为它们有助于肿瘤分级：低级别肿瘤不强化，而胶质母细胞瘤几乎总是强化。MRI似乎是研究星形细胞瘤不可或缺的：它在术前或治疗前评估期间能对病变进行出色的解剖分析，并且是确认那些在CT上未被发现或仅被怀疑的低级别病变的唯一可用方法。为避免漏诊这些肿瘤，每个近期发作癫痫的成年人都应使用T2加权自旋回波序列进行MRI检查。
