恶性肿瘤颅内转移的规律及磁共振成像的特征

目的 探讨恶性肿瘤颅内转移的规律及磁共振成像(MRI)的影像学特征。方法 对有恶性肿瘤病史且临床可疑颅内转移的1271例患者行MRI检查,采用Philips GyroscanT5．NTMR机型,扫描序列包括平扫横断位T1加权像、FLAIR图像及增强扫描横断位、矢状位、冠状位T1加权像。对全部患者的临床资料及MRI表现进行记录与分析。结果 在547例有脑转移的患者中,393例(71.9％)原发肿瘤为肺癌;约10％的恶性肿瘤患者以脑转移为首发症状而就诊;脑实质内转移526例,单纯脑膜转移21例。526例脑实质转移患者中,单发脑转移164例(31．2％),多发362例(68．8％)。注射造影剂后增强扫描,脑实质内转移瘤多表现为均匀或环形强化,硬脑膜．蛛网膜转移为大脑凸面连续的、较粗的弧线状强化,但不延伸至脑沟内,软脑膜．蛛网膜转移表现为脑表面连续的、可延伸至脑沟内的细线状或结节状强化。结论 发生颅内转移的原发肿瘤中,以肺癌最常见,其次为乳腺癌和消化道来源的肿瘤。应用MRI增强扫描,可以发现颅内早期单发的以及较小的转移病灶。

Intracranial metastasis of malignant tumors: clinical characteristics and MR imaging features

Objective To study the clinical characteristics and MR imaging features of intracranial metastasis from malignant tumors. Methods 1271 patients who had history of primary tumor and suspected of cranial metastasis had MRI on Philips Gyroscan T5-NT MR scanner. The sequences included pre-contrast T_1WI, FLAIR, and postcontrast transversal, sagittal, and coronal T_1WI. All of the clinical data and MRI features of the patients were recorded and analyzed. Results Of 547 patients with intracranial metastasis, 393 came from lung cancer( 71.9%), 10% of 547 patients were found to have the presenting symptoms of cranial metastasis. 526 had parenchymal cerebral metastasis, and 21 only meningeal metastasis. Of these 526 patients found to have brain metastasis, 164 had single metastasis (31.2%), and 362 multiple (68.8%). Most of the cerebral metastatic lesions showed uniform or ring enhancement after intravenous injection of contrast medium, dura-arachnoid metastasis showed continuous and thick-curve enhancement at the cerebral convex, but not extending to the sulcus, while pia-dura metastasis displayed as thin and linear or nodular enhancement extending to the adjacent sulci. Conclusion The most common primary lesion with metastasis to the brain were lung cancers, followed by breast and gastrointestinal cancers. By using gadolinium-DTPA enhanced MR imaging, many single and small cerebral metastasis could be found earlier.