鼻咽癌放射治疗后脑脊髓损伤的临床和影像学诊断

The clinical and image diagnosis of later radiation-induced encephalopathy and myelopathy after radiotherapy of nasopharyngeal carcinoma.

目的 探讨鼻咽癌患者放射治疗后脑脊髓放射性损伤的临床和影像学诊断。方法 对 32例鼻咽癌放射治疗脑脊髓放射性损伤患者的临床表现、CT及MRI表现进行回顾性分析。结果 32例中共发现 4 5个损伤病灶 ,颞叶 30个 (占脑损伤病灶的 70 % ) ,脑干 13个 ,颈段脊髓 2个。其中 6例放射性颞叶损伤无临床症状。CT对颞叶放射性损伤的检出率为 87% ,对脑干损伤的检出率仅 2 9%。放射性颞叶损伤在CT图象上主要表现为指状低密度。MRI检查T1WI图象上放射性脑脊髓损伤均表现为低或等信号 ,T2 WI图象上为高信号或混合信号 ,颞叶损伤可伴有周围指状分布水肿信号 ,86 %病灶有增强效应 ,中间有不增强区。结论 放射性脑脊髓损伤的临床表现无特征性 ,亦可无症状 ,CT及MRI表现具有一定的特征性 ,结合病史可做出诊断。MRI在诊断脑干、脊膜损伤上优于CT。

Objective To observe the clinical symptoms and CT and MR features of late delayed radiation induced encephalopathy and myelopathy after radiotherapy in nasopharyngeal carcinoma (NPC), and to evaluate the diagnositic modalities. Methods Thirty two patients with radiation induced encephalopathy and myelopathy in NPC were reviewed.All patients were diagnosed by clinical manifestations?CT or MR imaging. Results In these patients 45 lesions were observed, 30 lesions (70% of brain lesions)in temporal lobe, 13 in brain stem, 2 in spinal cord. Six patients with temporal lobe injury had no symptoms. 87% lesions in temporal lobe and only 29% brain stem lesions woold be revealed by CT. The lesions exhilited finger edema or hypodense on CT. The lesions in brain and spinal cord were hypointense or isointense on T1 weighted images, hyperintense or mixed intenses on T2 weighted images, rounded by edematous signal in some temporal lobe lesions. T1WI plus Gd DTPA showed enhancement in 86% lesions, with no enhancement inside the lesion. Conclusion No symptoms can be abserved in clinics for some patients in radiation induced encephalopathy. The CT and MRI findings are characteristic in radiation induced encephalopathy and myelopathy in nasopharyngeal carcinoma patients. MRI is better than CT in the diagnosis of damage to brain stem and spinal cord.