Intravoxel incoherent motion MRI for the differentiation of benign, intermediate, and malignant solid soft‐tissue tumors

Purpose To determine the diagnostic potential of apparent diffusion coefficient (ADC) and intravoxel incoherent motion (IVIM)‐derived parameters for the differentiation of benign, intermediate, and malignant solid soft‐tissue tumors. Materials and Methods The Institutional Review Board approved this prospective study, and informed consent was obtained. IVIM imaging was performed in 64 patients including 44 benign, 6 intermediate, and 14 malignant solid soft‐tissue tumors at 1.5T. The IVIM parameters of the soft‐tissue tumors were assessed using the Kruskal–Wallis test. The diagnostic performance of the parameters was evaluated using receiver operating characteristic (ROC) analysis. Results The ADC and true diffusion coefficient (D) values of malignancies (1.28 ± 0.31, 1.06 ± 0.23 [×10−3 mm2/sec]) were significantly lower than those of intermediate (1.49 ± 0.54, 1.30 ± 0.50 [×10−3 mm2/sec]), or benign soft‐tissue tumors (1.62 ± 0.37, 1.36 ± 0.33 [×10−3 mm2/sec]) (P = 0.007 and P = 0.009, respectively). In the differential diagnosis of malignancies from benign tumors, ADC demonstrated the highest area under the curve (Az) value (Az = 0.793). The perfusion fraction (f) values of intermediate soft‐tissue tumors (8.41 ± 2.73) were significantly different from those of benign and malignant tumors (14.70 ± 5.37 [P = 0.002]; 14.44 ± 5.31 [P = 0.021]). f showed the highest Az value in differentiating intermediate from benign, and malignant soft‐tissue tumors (Az = 0.90, and Az = 0.833, respectively). The pseudodiffusion coefficient (D*) values of malignant soft‐tissue tumors (144.40 ± 24.88 [×10−3 mm2/sec]) were significantly higher than those of benign tumors (124.96 ± 26.24 [×10−3 mm2/sec]) (P = 0.019). Conclusion IVIM imaging may be helpful for differentiating benign, intermediate, and malignant solid soft‐tissue tumors. Level of Evidence: 1 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2017;46:1611–1618.