Department of Imaging and Interventional Radiology, The Chinese University of Hong Kong, Prince of Wales Hospital, Ngan Shing St, Shatin, New Territories, Hong Kong.
Postgrad Med J. 2013 Jan;89(1047):39-46. doi: 10.1136/postgradmedj-2011-130075. Epub 2012 Sep 12.
Paediatric brain tumours commonly arise in the posterior cranial fossa. Early diagnosis is often challenging due to initial non-specific clinical symptoms, especially in very young children. The typical MR features of tumours in this region including medulloblastoma, ependymoma, juvenile pilocytic subtype of cerebellar astrocytoma, brain stem glioma and atypical teratoid-rhabdoid tumour are illustrated. Diffusion-weighted imaging and apparent diffusion coefficient values combined with signal characteristics on conventional MR sequences can usually differentiate low-grade from high-grade tumours. Prompt diagnosis is crucial as total surgical resection, which is only possible in localised disease, improves prognosis. A practical MR flow chart is introduced for differentiating different types of posterior cranial fossa tumours, which might be useful in clinical practice.
小儿脑肿瘤常发生在后颅窝。由于最初的非特异性临床症状，早期诊断往往具有挑战性，尤其是在非常年幼的儿童中。该区域肿瘤的典型磁共振成像（MR）特征包括髓母细胞瘤、室管膜瘤、小脑星形细胞瘤少年毛细胞型、脑干胶质瘤和非典型畸胎瘤-横纹肌样瘤。弥散加权成像和表观弥散系数值结合常规 MR 序列的信号特征通常可以区分低级别和高级别肿瘤。及时诊断至关重要，因为只有在局限性疾病中才有可能进行完全手术切除，从而改善预后。介绍了一种用于区分不同类型后颅窝肿瘤的实用 MR 流程图，这在临床实践中可能有用。
