Quality of Head and Neck Diffusion-weighted MR Imaging Using a Combination of the Periodically Rotated Overlapping Parallel Lines with Enhanced Reconstruction (PROPELLER) Sequence and Deep Learning Reconstruction

PURPOSE: To evaluate whether periodically rotated overlapping parallel lines with enhanced reconstruction-diffusion-weighted imaging (PROPELLER-DWI) combined with deep learning-based reconstruction (DLR) improves head and neck DWI, we conducted a primary comparison of PROPELLER-DWI with DLR at varying strengths and without DLR, and a secondary comparison of DLR-processed PROPELLER-DWI with DLR-processed single-shot echo-planar imaging (EPI)-DWI. METHODS: Ten healthy adults (8 males, 2 females) participated in the study. PROPELLER-DWI and single-shot EPI-DWI images were acquired using a 3-Tesla MRI system (Discovery MR750w; GE Healthcare, Waukesha, WI, USA) with various recon deep-learning strength (DLS) values: off (DLS-Off), low (DLS-L), medium (DLS-M), and high (DLS-H). We measured the SNR and contrast ratio on DWI images and value of coefficient of variation (CV) on apparent diffusion coefficient (ADC) maps for a quantitative evaluation. For a qualitative evaluation, we visually evaluated the overall image quality, degree of geometric distortion, and magnetic susceptibility artifacts. RESULTS: The SNRs for PROPELLER and EPI-DWI improved with the increase in the DLS level, with DLS-H showing a significantly higher SNR than DLS-Off. ADC maps demonstrated lower CVs at higher DLS levels, significantly lower in DLS-H than DLS-Off. The qualitative evaluation revealed that PROPELLER-DWI with DLR (at all DLS levels: -L, -M, and -H) provided significantly better overall image quality than that without DLR. In addition, PROPELLER-DWI demonstrated significantly higher qualitative scores across all evaluation items (i.e., overall image quality, geometric distortion, and magnetic susceptibility artifacts) compared with EPI-DWI. CONCLUSION: In head and neck DWI, PROPELLER-based acquisition with DLR enabled the acquisition of visually superior image quality. This approach is clinically useful for the head and neck radiology.