单发脑转移瘤MRI诊断价值

MR imaging manifestation of single Brain Metastasis

目的 提高对单发脑转移瘤 (SBM) MRI诊断和鉴别诊断的准确性。方法 回顾性分析经临床及病理证实的 5 1例 SBM的 MRI表现。结果 本组 SBM幕上 3 7例 (72 .5 % ) ,其中右侧大脑半球 1 7例 (4 5 .9% ) ,左侧大脑半球2 0例 (5 4.1 % )。瘤体位于皮质和皮质下区 3 7例 (72 .5 % ) ,双侧大脑半球分布无明显差异。SBM在 T1 WI像上主要表现为等或低信号 ,T2 WI呈高信号 ,增强扫描所有病灶均呈明显环状及结节状强化。环状强化 40例 (78.4% ) ,环壁厚薄不均 ,界限清楚 ,形态多不规则 ;结节状强化 1 1例 (2 1 .6% ) ,多数病灶内部信号不均。幕上病灶 、 度瘤周水肿 3 4例(66.7% ) ,瘤体与水肿比例不对称呈小瘤体、大水肿的表现。结论 SBM患者 MRI具有一定的特征性 ,对比增强 MRI对诊断 SBM有重要价值。

Objective To improve the accuracy of MRI's diagnosis and differential diagnosis of single brain metastasis (SBM).Methods Fifty-one cases of SBM diagnosed by MRI and confirmed by pathology were analyzed retrospectively.Results On the MRI,37 SBM patients' (72.5%) lesion site was located on the supratentorial region of the brain,17 patients' (45.9%) on the right cerebrum,20 patients' (54.1%) on the left cerebrum,37 patients' on the cerebral cortex and subcortical region respectively. The shapes of the lesion site in the patients were circular in 40 cases (78.4%) and nodal in 11cases(21.6%) with obvious enhancement on enhanced scans. There were no apparent differences between the lesion site on the right cerebral hemispere and on the left one. The major demonstration of SBM on T1WI were equal or low signals,while on T2WI high signals. Most lesions were irregularly with nonhomogeneous thickened wall,and markedly enhanced with obvious edema around the metastasis,presenting asymmetrically with big edema and small tumor body.Conclusions Contrast-enhanced MRI scans seen to demonstrate some importance of diagnostic value for SBM because SBM had displayed certain characteristic signs on the MRI scans.