FOCUS-MUSE DWI in Primary Rectal Cancer: Comparison with FOCUS, MUSE, and Single-shot DWI

Abstract Background To assess the reliability of constrained undistorted single-shot diffusion-weighted imaging (FOCUSDWI), multiplexed sensitivity-encodingDWI (MUSEDWI), single-shot echo planar imaging DWI (SSDWI) and the combination of FOCUS and MUSE (FOCUS-MUSEDWI) in primary rectal cancer by evaluating image quality and T staging performance. Methods Patients with primary rectal cancer underwent 3. 0T MR scans with four DWI sequences. Signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and apparent diffusion coefficient (ADC) values were measured. T stage and subjective image quality were assessed. Statistical analyses included intraclass correlation coefficient (ICC), Fleiss Kappa test, Friedman test, Chi-square tes, Paired t-test, and Spearman correlation analysis. Results A total of 45 patients (mean age: 60. 45 ± 9. 79, 30 men) were evaluated. FOCUS-MUSEDWI exhibited the highest CNR (6. 43 ± 0. 94 and 6. 44 ± 0. 90 for two readers, respectively), adequate SNR (49. 81 ± 6. 60 and 49. 67 ± 6. 09 for two readers, respectively) with the best ADC repeatability (mean absolute difference: 8. 44). No significant T staging differences were observed among DWI sequences (p ≥ 0. 908). FOCUS-MUSEDWI achieved the highest total image quality score (median value: 16) compared with other three sequences (p ≤ 0. 001). Good to excellent agreement observed in both interobserver and intraobserver assessments (kappa > 0. 600). Conclusion FOCUS-MUSEDWI demonstrated good reliability with commendable T staging performance, the best ADC repeatability, sufficient SNR, the best CNR among four DWI sequences and could be the recommended sequence for clinical evaluation.