Prospective Evaluation of Accelerated Brain MRI Using Deep Learning-Based Reconstruction: Simultaneous Application to 2D Spin-Echo and 3D Gradient-Echo Sequences

Abstract

Objective: To prospectively evaluate the effect of accelerated deep learning-based reconstruction (Accel-DL) on improving brain magnetic resonance imaging (MRI) quality and reducing scan time compared to that in conventional MRI. Materials and Methods:This study included 150 participants (51 male; mean age 57.3 16.2 years).Each group of 50 participants was scanned using one of three 3T scanners from three different vendors.Conventional and Accel-DL MRI images were obtained from each participant and compared using 2D T1-and T2-weighted and 3D gradient-echo sequences.Accel-DL acquisition was achieved using optimized scan parameters to reduce the scan time, with the acquired images reconstructed using U-Net-based software to transform low-quality, undersampled k-space data into high-quality images.The scan times of Accel-DL and conventional MRI methods were compared.Four neuroradiologists assessed the overall image quality, structural delineation, and artifacts using Likert scale (5-and 3-point scales).Inter-reader agreement was assessed using Fleiss' kappa coefficient.Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated, and volumetric quantification of regional structures and white matter hyperintensities (WMHs) was performed.Results: Accel-DL showed a mean scan time reduction of 39.4% (range, 24.2%-51.3%).Accel-DL improved overall image quality (3.78 0.71 vs. 3.36 0.61, P < 0.001), structure delineation (2.47 0.61 vs. 2.35 0.62, P < 0.001), and artifacts (3.73 0.72 vs. 3.71 0.69, P = 0.016).Inter-reader agreement was fair to substantial ( = 0.34-0.50).SNR and CNR increased in P = 0.02; 12.4 4.1 vs. 4.4 11.2, P = 0.02).Bland-Altman plots revealed no significant differences in the volumetric measurements of 98.2% of the relevant regions, except in the deep gray matter, including the thalamus.Five of the six lesion categories showed no significant differences in WMH segmentation, except for leukocortical lesions (r = 0.64 0.29).Conclusion: Accel-DL substantially reduced the scan time and improved the quality of brain MRI in both spin-echo and gradientecho sequences without compromising volumetry, including lesion quantification.