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 (FOCUS_DWI), multiplexed sensitivity-encoding_DWI (MUSE_DWI), single-shot echo planar imaging DWI (SS_DWI) and the combination of FOCUS and MUSE (FOCUS-MUSE_DWI) 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-MUSE_DWI 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-MUSE_DWI 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-MUSE_DWI 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.