Distortion-Free High-Resolution PROPELLER-DWI: Technical Advances and Initial Demonstration for the Prostate

Abstract

Purpose: To develop and evaluate an integrated acquisition and reconstruction framework for distortion-free, high-resolution prostate diffusion-weighted imaging (DWI). Methods: PROPELLER-DWI combines pulsed-gradient spin-echo diffusion preparation, an interleaved gradient-and-spin-echo PROPELLER acquisition with golden-angle blade rotation, and self-supervised joint reconstruction and denoising. It was compared with conventional NUFFT reconstruction and MPPCA denoising in a NIST/QIBA diffusion phantom, 25 volunteers, and 4 clinical patients undergoing 3T prostate MRI across three spatial-resolution settings and two b-values (50 and 1000 s/mm2). Reader studies compared geometric fidelity, image quality, and overall preference with clinical single-shot EPI-DWI. Results: PROPELLER-DWI preserved prostate geometry in cases where EPI-DWI showed susceptibility-induced distortion, signal loss, and metal-related artifacts. Self-supervised reconstruction improved noise suppression, with the greatest benefit at higher spatial resolution. Across all resolutions, PROPELLER-DWI had significantly higher geometric fidelity than EPI-DWI, and radiologist preference increased with the severity of EPI distortion. ADC measurements remained consistent across resolutions and comparable to clinical EPI-DWI, whereas EPI-DWI ADC varied with increasing resolution. Retrospective reduced-shot reconstruction also supported shorter scan times. Conclusion: PROPELLER-DWI enables distortion-free, high-resolution prostate DWI while preserving quantitative diffusion measurements, providing a practical alternative for technically challenging prostate MRI and applications requiring improved geometric fidelity.