Is CT Necessary in the Diagnosis of Soft Tissue Masses?

摘要

Background Computed tomography (CT) is still widely used in the diagnosis of soft tissue masses. However, overuse of CT brings increased radiation exposure and increased medical expenditure. The purpose of this study was to evaluate the necessity for CT in comparison with magnetic resonance (MR) imaging in the diagnosis of soft tissue masses. Methods Forty-seven patients with soft tissue masses who underwent both CT and MR imaging were enrolled in this study. Contrast enhancement was performed in 27 cases out of the total 47 CT studies. Images were analyzed for 1) location; 2) extension; 3) internal structure; 4) benign and malignant differentiation of soft tissue masses. Two musculoskeletal radiologists scored each factor independently. Results MR imaging scores of all four factors were significantly better than plain CT scores. Administration of contrast material in CT, improved agreement and kappa between CT and MR imaging scores to some extent. Diagnosis of benign and malignant differentiation was equivalent in enhanced CT and MR imaging, whereas CT scores were still inferior to MR imaging in terms of location, extension and internal structure. Compared to MR imaging as the gold standard, the sensitivity and specificity of CT diagnosis in terms of location, extension and internal structure were relatively low, but were high in the diagnosis of benign and malignant differentiation. Conclusion These results suggest that MR imaging is superior to CT in the diagnosis of soft tissue masses. Use of CT is considered to be redundant when MR imaging is available.