Dynamic contrast enhanced MRI in the differential diagnosis of soft tissue tumors

Purpose: The value of the dynamic contrast enhanced-magnetic resonance imaging (DCE-MRI) in differentiating benign and malignant soft tissue tumors was investigated. Materials and methods: Turbo FLASH DCE-MRI was performed on 22 subjects (2–74 years) with soft tissue tumors. Enhancement in the first min ( E max/1), second min ( E max/2) and maximum peak enhancement ( E max), and steepest slope were calculated. Discriminant analyses were performed to reveal parametric differences of benign and malignant lesions. Results: Diagnosis of benign ( N = 10) tumors were hemangioma ( n = 3), neurogenic tumor ( n = 3) lipoma ( n = 2), giant cell tumor ( n = 1) and desmoid ( n = 1), whereas malignant lesions ( N = 12) were classified as liposarcoma ( n = 5), malignant fibrous histiocytoma ( n = 5) and synovial sarcoma ( n = 2). For malignant lesions E max/1 was 65–198%, E max/2 was 65–145%, E max was 78–198%, and steepest slope was 1.45–4.06. For benign lesions these values were 4–98%, 5–105%, 7–125% and 0.67–2.57, respectively. To determine the relation between the variables analysed, Pearson correlation coefficients were calculated. E max was found to be highly correlated with other variables ( rxy>0.86, P < 0.0001). Consequently, this variable was excluded from the discriminant analysis. In order to determine discrimination of malignant and benign tumors using E max/1, E max/2, and steepest slope of the enhancement curve logistic regression was applied to the above mentioned data. When combined these parameters had a 95.5% of overall accuracy in classifying benign and malignant lesions ( P = 0.004). Conclusion: DCE-MRI parameters that thought to be the surrogate markers of tumoral microcirculation and tissue perfusion provides a specific preoperative diagnosis. Dynamic imaging parameters are therefore advocated for monitoring the effect of chemotherapy in soft tissue tumors.