鼻咽癌颅内侵犯的CT与MRI诊断

目的 探讨鼻咽癌颅内侵犯的CT与MRI表现及诊断价值。资料与方法 回顾性分析MRI发现颅内肿块,并经病理证实为鼻咽癌颅内侵犯者15例,其中8例作了CT扫描。结果 MRI全部发现颅内病变,并作出正确诊断,表现为中颅凹鞍旁的软组织肿块,有明显强化,冠状位增强扫描可见连接鼻咽部肿块与颅内肿块的条状强化影,2例侵犯岩尖及后颅窝。15例同侧乳突均有炎症。作CT检查的8例中,3例平扫未发现颅内病变,3例增强扫描发现病变但未能作出正确的定性诊断。结论 MRI是诊断鼻咽癌颅内侵犯的首选方法;CT有一定的局限性,可以通过增强扫描、骨窗观察颅底骨质有无破坏、乳突有无炎症及必要时扩大扫描范围、加扫冠状位等方法提高对本病的诊断准确率。

CT and MRI Diagnosis of Intracranial Involvement of Nasopharyngeal Carcinoma

Objective To discuss CT and MRI features of intracranial involvement from nasopharyngeal carcinoma.Materials and Methods Imaging findings in 15 patients with pathologically-proved intracranial involvement due to nasopharyngeal carcinoma were retrospectively analyzed. MRI scanning was performed in all 15 cases, and additional CT scanning in 8.Results All the intracranial lesions could be detected on MRI, and correct diagnosis was made. The lesion presented as soft-tissue mass at para-sella turcia in the middle cranium with obvious enhancement. On enhanced coronal scans, an enhanced narrow strip could be seen, which connected the nasopharyngeal lesion with the intracranial mass. Petrous apex and posterior cranium were affected in 2 cases. Ipsilateral masotiditis occurred in all 15 cases. Of 8 cases receiving CT scanning, no intracranial lesion was found in 3 on plain CT scans, and intracranial lesion was detected on enhanced CT scans in 3, whereas qualitative diagnosis could not be made. Conclusion In diagnosing intracranial involvement of nasopharyngeal carcinoma, MRI is of choice, while CT has some limitations although enhanced CT scanning and bone window can help judge bony destruction and masotiditis.