Reverse Encoding Distortion Correction of Female Pelvic Diffusion-weighted Imaging on a 1.5-T MR System: Influence on Image Quality and Apparent Diffusion Coefficient Measurements for Both In Vitro and In Vivo Studies

Purpose: To evaluate whether reverse encoding distortion correction (RDC) improves image quality and maintains apparent diffusion coefficient (ADC) measurements in diffusion-weighted imaging (DWI) on female pelvic MRI using a 1.5-T in in vitro and in vivo studies. Methods: This retrospective, institutional review board-approved study included both in vitro and in vivo analyses of 31 women (mean age, 41 ± 15 years; range, 24-80 years) who underwent pelvic MRI between January and March 2022. T2-weighted image (T2WI) and DWI with and without RDC were acquired, and ADC maps were generated. Quantitative metrics included SNR, contrast-to-noise ratio (CNR), ADC values, and deformation ratio (DR), defined as the proportional area discrepancy between DWI and T2WI for the uterine corpus, cervix, ovary, and lesions. Qualitative assessments-overall image quality (OIQ), deformation severity (DS), and diagnostic confidence level (DCL)-were independently scored by 2 blinded radiologists using 5-point scales. Results: In vitro SNR and ADC values showed no significant differences between DWI with and without RDC, with strong correlations to reference measurements (ρ = 0.99, P < 0.001). In vivo, SNR, CNR, and ADC values of the myometrium, cervix, and ovary did not differ significantly between 2 methods (P > 0.05). DRs were significantly lower in DWI with RDC than in DWI without RDC (P ≤ 0.0003). ADC values showed strong correlations between DWI with and without RDC on uterine corpus, cervix, ovary and lesions (ρ = 0.82-0.90, P < 0.001). Qualitative scores improved with RDC: higher OIQ (P = 0.0004), lower DS (P = 0.0004), and higher DCL (P = 0.03). Interobserver agreement ranged from substantial to almost perfect (κ = 0.78-0.97). Conclusion: RDC improves image quality and reduces image distortion in DWI on female pelvic MRI at a 1.5-T, while maintaining ADC measurements in in vitro and in vivo settings.