磁共振灌注成像对脑内占位性病变鉴别诊断的价值

摘要

目的：探讨磁共振灌注成像对脑内占位性病变鉴别诊断的价值。方法：选取55例经临床病理检查证实的脑内肿瘤病人,回顾性分析其磁共振灌注图像、随访结果,并绘制时间-信号强度曲线,比较不同类型肿瘤相对脑血容量图、相对脑血流量,和相对平均通过时间参考图及灌注曲线的特点。结果：所有入组病例经灌注成像扫描后,19例病人诊断为胶质瘤,8例诊断为脑转移瘤,5例诊断为脑原发性淋巴瘤,并经病理证实。23例胶质瘤术后放疗后病人中,15例诊断为胶质瘤术后复发,最终经二次手术和随访证实；8例诊断为胶质瘤术后放疗后放射性脑坏死,随访3~6mo病变无明显变化。结论：磁共振灌注成像可以揭示相应感兴趣区是否存在肿瘤新生血管,提供组织中微观血流动力学信息,为临床提供病理生理学信息。肿瘤内和肿瘤周围相对局部脑血容量变化及时间-信号强度曲线可对胶质瘤与转移瘤、淋巴瘤和放疗后脑坏死的鉴别诊断提供帮助,具有较高的临床应用价值。%Objective:To discuss the differential diagnosis value of PWI scan for the brain neoplasms. Methods:55 patients were confirmed by clinical pathology examination with the brain neoplasms. According to the Perfusion-weighted imaging ( PWI ) images and follow-up results, 4 parameter maps below were retrospective analyzed:the relative cerebral blood volume( rCBV) images, relative cerebral blood flow( rCBF) images,relative mean transit time( MTT) images and the time-signal intensity curve. Results:After PWI scanning,19 patients were diagnosed with glioma,8 patients with metastatic carcinoma,5 patients with lymphomas,and all of them were confirmed by pathology. In 23 patients who had glioma after operation and radiotherapy,15 of them were confirmed recurrence by the operation and follow-up results,8 of them were diagnosed with radiation-induced brain injury because the neoplasms were not changed obviously after several recheck in 3~6months. Conclusion:The PWI technique can reveal the lesion vascular distribution and quantity angiogenesis of tumor and provide valuable physiopathologic information. The rCBF in tumor and peri-tumor and the time-signal intensity curve have important value in diagnosing tumor recurrence or radiation-induced brain injury. And it has great advantages in the differential diagnosis of the glioma,the metastatic carcinoma and lympho-mas.