扩散加权成像在儿童四脑室区肿瘤诊断中的价值

目的：探讨扩散加权成像（DWI）在儿童四脑室区常见肿瘤诊断中的价值。方法：回顾性分析2003年6月至2012年10 月经手术病理证实的42例儿童四脑室区肿瘤的MRI及临床资料。所有病例均进行了 DWI。结果：42例中，毛细胞型星形细 胞瘤（I级）5例，星形细胞瘤（II级）9例，室管膜瘤12例（I级2例，II级6例，II级4例），髓母细胞瘤16例。在DWI合成图上，毛细胞型星形细胞瘤呈等或低信号，星形细胞瘤呈等或稍高信号，室管膜瘤呈稍高或明显高信号，髓母细胞瘤呈明显高信 号。肿瘤实质部分的ADC值由高到低依次为低级星形细胞瘤（I？II级）、室管膜瘤和髓母细胞瘤，分别为（1.48±0. 16） ×10^-3 mm2/s、（l. 11±0. 12）×10^-3 mm2/s 和（0. 73 ± 0. 09 ） ×10^-3 mm2/s,两两比较差异均有统计学意义（P 〈0.05）。以 ADC值0. 82×10^-3 mmVs和1.32×10^-3 mm2/s作为阈值的诊断正确率为95. 2 % （40/42）。结论：DWI在低级星型细胞瘤、 室管膜瘤及髓母细胞瘤的诊断及鉴别诊断中有重要价值。

THE APPLICATION OF DIFFUSION WEIGHTED IMAGING IN THE DIAGNOSIS OF TU-MORS IN THE FOURTH VENTRICLE REGION IN CHILDREN

Objective：To explore the application of apparent diffusion coefficient （ADC） values in the diag-nosis of tumors in the fourth ventricle region in children. Methods ： Forty-two cases with histologically proved primary tumors in the fourth ventricle region were enrolled this study, from June 2003 to October 2012. The ADC value for each case was analyzed retrospectively. Results： Forty-two cases （5 juvenile pilocytic astrocytomas, 9 astrocytomas, 12 ependymaes and 16 medulloblastomaes） were included. On DWI maps,juvenile pilocytic astrocytomas were hypointense or isointense, astrocytomas were isointense or slightly hyperintense, ependymaes were slightly or obvius hyperintense, and medulloblastomaes were obvi- us hyperintense. The ADC values of the solid part in tumors decreasely were astrocytomas （I？II grade）, ependymaes and medulloblastomaes,and the ADC mean were （1. 48 ±0. 16） ×10^-3 mm2/s, （1. 11 ± 0. 12） ×10^-3 mm2/s and （0. 73 ± 0. 09）×10^-3 mm2/s. Differences of ADC values among these three different types of tumors were statistically significant （ P 〈0. 05）. Conclusion： The application of DWI in the diag-nosis and differential diagnosis of astrocytomas, ependymaes and medulloblastomaes is very important.