Enhancing liver diffusion-weighted imaging quality with correlation-weighted averaging: notable benefits in the left hepatic lobe.

PURPOSE: To evaluate the feasibility of correlation-weighted averaging factor (CWAF) in liver diffusion-weighted imaging (DWI). MATERIALS AND METHODS: This prospective study included 103 participants who underwent liver MRI. DWI were reconstructed using both original data (DWI) and CWAF-corrected data (DWI). Two radiologists independently assessed high-b DWI images for overall image quality, image noise, hepatic edge sharpness, and lesion conspicuity in the right and left lobes using five-point scales. Signal intensity ratio (SIR) and apparent diffusion coefficient (ADC) values were measured in four hepatic segments and in liver lesions, with lesion measurements analyzed separately for each lobe. These parameters were compared between the two image sets. RESULTS: The scores for overall image quality (P < 0.001), image noise (P < 0.001), and hepatic edge sharpness in the right lobe P = 0.001 were higher in DWI compared with DWI. In contrast, hepatic edge sharpness (P < 0.001) and lesion conspicuity (P < 0.001) in the left lobe were superior in DWI. Liver and lesion SIRs were higher in DWI across all segments than in DWI (P < 0.007). Liver ADC values were lower in DWI than in DWI in all segments (P < 0.001). Lesion ADC values were also lower in DWI than in DWI in the right lobe (P < 0.001) but were not different in the left lobe P = 0.48. CONCLUSION: CWAF improved hepatic edge sharpness and lesion conspicuity in the left lobe, although overall image quality was slightly reduced. ADC values were generally lower in DWI than in DWI.