Comparison between intravoxel incoherent motion and splenic volumetry to predict liver fibrosis in preoperative patients

Abstract

Abstract Background Hepatic fibrosis (HF) is an important factor in patients for liver surgery, because HF may lead to surgical restrictions and affect the patient's prognosis. Intravoxel incoherent motion (IVIM) is used for HF investigation, and the restricted diffusion observed in patients with cirrhosis may be related to D* variations. Splenic volumetry (SV) has been reported to be effective in the evaluation of severe cirrhosis. Our purpose of this study is to compare the predictive ability of IVIM and SV for HF. Methods This study included 67 patients with pathologically staged HF who underwent magnetic resonance imaging and computed tomography (CT). SV was semi-automatically measured from the CT images. IVIM indices, such as the slow diffusion coefficient related to molecular diffusion (D), fast diffusion coefficient related to perfusion in microvessels (D*), apparent diffusion coefficient (ADC), and perfusion-related diffusion fraction (f), were calculated with 10 b-values by two observers (R1 and R2). Receiver operating characteristic curve analysis was performed to determine the predictive ability of HF for IVIM and SV/body surface area (BSA). The inter-rater agreement was discussed for each IVIM parameter. Results D (P = 0.718 for R1, P = 0.087 for R2) and D* (P = 0.513, P = 0.708, respectively) showed a poor correlation with HF grade. ADC (P = 0.034 and P = 0.528, respectively) and f (P < 0.001 and P = 0.007, respectively) decreased as HF progressed, whereas SV/BSA increased (P = 0.015 for R1). The AUCs of SV/BSA (0.649–0.698 for R1) were higher than those of f (0.575–0.683 for R1 + R2) for severe HF (≥ F3-4 and ≥ F4), although the AUCs of f (0.705–0.790 for R1 + R2) were higher than those of SV/BSA (0.628 for R1) for mild or no HF (≤ F0-1). However, no significant differences in the ability to identify HF were observed between IVIM and SV/BSA. Conclusions SV/BSA allows a higher estimation for evaluating severe HF than IVIM. IVIM is more suitable than SV/BSA for the assessment of mild or no HF.