Application of magnetic resonance imaging in the diagnosis of soft tissue sarcoma

Objective To evaluate the diagnostic value of magnetic resonance imaging (MRI) in the diagnosis of soft tissue sarcoma. Methods Seventy-four soft tissue tumors patients having underwent plain and enhanced MRI scans were selected. A retrospective case-control study was conducted to compare the demographic and MRI characteristics between 32 cases of soft tissue sarcoma and 42 cases of benign soft tissue tumor. The examined MRI characteristics included lesion location, morphology, size, signal uniformity, intratumoral sign, sign outside the tumor and intensity pattern, et al. The MRI characteristics were compared between 2 groups. Results The 32 patients with soft tissue sarcoma included 7 cases with lipoblastoma, 5 cases with pleomorphic undifferentiated sarcoma, 5 cases with fibrosarcoma, 5 cases with synovial sarcoma 5 cases, 4 cases with dermatofibrosarcoma protuberant, 2 cases with low-grade fibromyxoid sarcoma, 2 cases with alveolar soft part sarcoma, 1 case with leiomyosarcoma, and 1 case with histiocytic sarcoma. The 42 patients with benign soft tissue tumor included 15 cases with neurilemmoma, 9 cases with angioma, 8 cases with neurofibroma, 6 cases with lipoma, and 4 cases with angiolipoma. After controlling for the potential confounding effects of sex and age, whether there was high signal on T2WI and whether the tumor boundary was clear can help for distinguishing soft tissue sarcoma and benign tumor. The occurrence of high signal on T2WI was a risk factor for soft tissue sarcomas (OR= 25.05, 95% CI 4.04 to 155.28), and tumors whose boundaries were less clear (OR= 18.84, 95% CI 2.98 to 118.99) and unclear (OR= 26.59, 95% CI 3.79 to 186.71) were more likely to be soft tissue sarcomas compared to those with clear boundaries. Conclusions The MRI characteristics of soft tissue sarcomas can be used for accurate diagnosis of the tumors before treatment. Key words: Tumors of soft tissue; Magnetic resonance imaging; Diagnosis; Identification