SPECT/CT与MRI对鼻咽癌颅底骨侵犯诊断价值的比较

Comparative study of SPECT/CT and MRI in detecting skull-base bone invasion of nasopharyngeal carcinoma

目的:探讨单光子发射计算机断层显像(single-photon emission computed tomography,SPECT)/CT及磁共振成像(magnetic resonance imaging,MRI)对鼻咽癌(nasopharyngeal carcinoma,NPC)颅底骨侵犯(skull-base bone invasion,SBBI)的诊断价值。方法:回顾性分析83例(男性57例,女性26例;年龄为16～72岁)初诊未治且由病理学检查证实的NPC患者,比较头颅^(99m)Tc-MDP SPECT/CT图像与鼻咽部MRI图像。另设正常对照10例,仅进行头颅SPECT/CT。计算SPECT/CT图像矢状面颅底异常浓集最高计数区域与高位颈椎体处比值(L/S),L/S>1视为SBBI。以临床和鼻咽MRI检查结果为金标准,计算SPECT/CT及MRI判断颅底骨侵犯的灵敏度、特异度、准确率、阳性预测值、阴性预测值。结果:随访确诊为NPC SBBI的患者有64例。MRI检查真阳性64例,假阳性1例,真阴性18例;SPECT/CT检查真阳性60例,假阳性3例,真阴性16例,假阴性4例。61例患者在MRI和SPECT/CT上均表现为SBBI。MRI诊断NPC SBBI的灵敏度、特异度、漏诊率及误诊率分别为100%、94.74%、0及5.26%;SPECT/CT的相应指标分别为93.75%、84.21%、6.25%及15.79%。结论:SPECT/CT与MRI诊断NPC SBBI具有相似的诊断效能,但对各骨的诊断效能不同,尤其在颞骨诊断上有差异。

Objective: To evaluate the value of single-photon emission computed tomography(SPECT)/CT and magnetic resonance imaging(MRI) in the diagnosis of skull-base bone invasion(SBBI) in the patients with nasopharyngeal carcinoma(NPC).Methods: Eighty-three first-visit NPC patients(57 males, 26 females;age range 16-72 years) were enrolled in this retrospective study. The patients underwent SPECT/CT and MRI to confirm whether the skull base was invaded. 99mTc-MDP SPECT and MRI were performed in one week. The region of interest(ROI) was drawn on the area of the suspected skull base and the upper cervical vertebral body on the slices. A lesion-to-spine ratio(L/S) was calculated. L/S>1 indicated malignant. The sensitivity, specificity,positive predictive value, negative predictive value and accuracy of the two imaging modalities were calculated. Results: Sixty-four NPC patients were found SBBI in follow-up imaging. The diagnostic sensitivity, specificity, missed diagnosis rate and misdiagnosis rate of MRI were 100%, 94.74%, 0, 5.26%, respectively. The correspondence parameters of SPECT/CT were 93.75%, 84.21%, 6.25%,15.79%, respectively. There was no significant difference in the diagnostic efficiency between the two imaging modalities(χ2=1.37,P=0.242). Conclusion: SPECT/CT and MRI have similar diagnostic efficiency in detecting SBBI. MRI can detect more lesions than SPECT/CT, but SPECT/CT has potential advantages in detecting tiny bone lesions in the skull.