Comparison of IDEAL-IQ and IVIM-DWI for Differentiating between Alpha Fetoprotein-Negative Hepatocellular Carcinoma and Focal Nodular Hyperplasia

Background: To compare the differential diagnostic value of iterative decomposition of water and fat with theecho asymmetrical and least-squares estimation quantitation sequence (IDEAL-IQ) with that of intravoxel incoherent motion diffusion-weighted imaging (IVIM DWI) in differentiating between alpha fetoprotein (AFP)-negative hepatocellular carcinoma (HCC) and focal nodular hyperplasia (FNH). Materials and Methods: A total of28 AFP-negative HCC cases and 15 FNH cases were scanned using the IDEAL-IQ and IVIM-DWI magnetic resonance imaging (MRI) protocols. Two radiologists independently assessed the fat fraction (FF) and the iron levelsurrogate (R2*) derived from the IDEAL-IQ images and the apparent diffusion coefficient (ADC), pure diffusioncoefficient (D), pseudo-diffusion coefficient (D*), and perfusion fraction (f) derived from the IVIM-DWI images.The intraclass correlation coefficients (ICC) were estimated to evaluate the agreement repeatability between thetwo readers. The area under the curve (AUC) of a receiver operating characteristics curve was used to comparethe diagnostic efficiency of the parameters extracted from the two techniques. Results: The lesions in the HCCgroup had significantly higher FF than the FNH group (8.284 ± 5.756 vs. 2.559 ± 1.247, P < 0.05). ADC and Dvalues were lower in the HCC lesions when compared with the FNH lesions (1.310 ± 0.253 and 0.909 ± 0.192,respectively, vs. 1.624 ± 0.304 and 1.230 ± 0.314; ×10⁻³ mm²/s). The FF parameter had the highest AUC (0.923)followed by D (0.864) and ADC (0.854). Conclusions: FF derived from IDEAL-IQ, and ADC and D derived fromIVIM-DWI were able to differentiate AFP-negative HCC from FNH. IDEAL-IQ showed better performance forthe differentiation of FNH from HCC than the IVIM-DWI-derived parameters.