Study of the uniformity between MRI and 18F-FDG PET/CT in detection of spinal metastatic tumor / 实用放射学杂志

ABSTRACT

Objective To compare the uniformity between spine MRI and 18F-FDG PET/CT in detection of spinal metastatic tumor, and to analyze the reasons for the discrepancy between them.Methods Data of 42 malignant tumor patients underwent spine MRI and 18F-FDG PET/CT were analyzed retrospectively.And the two tests were underwent within 30 days.The author censused and analyzed the number of centrums with metastatic tumor detected by spine MRI and 18F-FDG PET/CT,and supposed that 18F-FDG PET/CT was gold standard,to evaluate the sensitivity and specificity of spine MRI.The inconsistent between two tests was analysed.Results The study included 509 centrums of 42 patients.123 positive centrums (24.2%) were detected on spine MRI,and 114 positive centrums (22.4%) on 18F-FDG PET/CT(P=0.22>0.05).The uniformity between two tests was good (Kappa=0.76).Supposing that 18F-FDG PET/CT was gold standard,the sensitivity,specificity,positive predictive value, negative predictive value,false negative rate and false positive rate of spine MRI was 85.1%(97/114),93.4%(369/395),85.1%(97/114),93.4% (369/395),14.9%(17/114) and 6.6%(26/395) respectively.43 centrums of 14 patients were diagnosed inconsistently by spine MRI and 18F-FDG PET/CT.The main reasons for the inconformity were as following types of primary tumors, insensitivity of spine MRI for diffuse scattered spinal metastatic tumors, the existence of misdiagnosis on spine MRI, misdiagnosis of spine MRI for metastatic lesions located in the vertebral appendix and paramedian vertebral body,misdiagnosis of 18F-FDG PET/CT for metastatic lesions located in the sacral centrum, existence of false positive on 18F-FDG PET/CT and so on.Conclusion The uniformity between spine MRI and 18F-FDG PET/CT is good.The inconformity still existes in some cases.Carefully comparative analysis of them contributes to find metastatic lesions.