Evaluation of hepatic focal lesions using diffusion‐weighted MR imaging: Comparison of apparent diffusion coefficient and intravoxel incoherent motion‐derived parameters. Issue 2 (30th April 2013) - Yoon, Jeong Hee
Abstract : Purpose: To determine whether parameters obtained from intravoxel incoherent motion (IVIM)‐diffusion‐weighted imaging (DWI) using multiple b‐values can improve characterization of common focal liver lesions (FLLs), compared with the apparent diffusion coefficient ( ADC total ). Materials and Methods: Our Institutional Review Board approved this retrospective study and informed consent was waived. In all, 142 patients with 169 FLLs underwent liver magnetic resonance imaging (MRI) including IVIM‐DWI with multiple b factors at 3.0T. ADC total and IVIM‐DWI‐derived parameters including true diffusion ( Dt ), pseudodiffusion ( Dp ), and perfusion fraction ( f ) were calculated for each lesion and compared using dedicated software. Results: Dt and ADCtotal were significantly lower in malignancies (0.95 ± 0.21, 1.14 ± 0.24, (×10 −3 mm 2 /sec)) than in benign FLLs (1.61 ± 0.34, 1.72 ± 0.37, (×10 −3 mm 2 /sec)). In the differential diagnosis of malignancies from benign lesions, Dt (Az value: 0.971) showed better diagnostic performance than ADCtotal (Az: 0.933) ( P < 0.0005). Dt (Az: 0.961) also showed better diagnostic performance than ADCtotal (Az: 0.919) in differentiating hypervascular malignancies from benign hypervascular FLLs ( P < 0.0005). In addition, Dp and f were significantly higher in hypervascular FLLs (35.74 ± 20.08 (×10 −3 mm 2 /sec), 28.14 ± 11.82 (%)) than hypovascular FLLs (21.87 ± 13.8 (×10 −3 mm 2 /sec), 12.2 ± 5.92 (%)) ( P < 0.0001). Conclusion: Dt provided better diagnostic performance than ADCtotal in differentiating benign from malignant lesions. Dp and f were significant parameters for diagnosing hypervascular FLLs.J. Magn. Reson. Imaging 2014;39:276–285 . ©2013 Wiley Periodicals, Inc .