Accelerated Cine Cardiac MRI Using Deep Learning‐Based Reconstruction: A Systematic Evaluation

Abstract

BackgroundBreath‐holding (BH) for cine balanced steady state free precession (bSSFP) imaging is challenging for patients with impaired BH capacity. Deep learning‐based reconstruction (DLR) of undersampled k‐space promises to shorten BHs while preserving image quality and accuracy of ventricular assessment.PurposeTo perform a systematic evaluation of DLR of cine bSSFP images from undersampled k‐space over a range of acceleration factors.Study TypeRetrospective.SubjectsFifteen pectus excavatum patients (mean age 16.8 ± 5.4 years, 20% female) with normal cardiac anatomy and function and 12‐second BH capability.Field Strength/Sequence1.5‐T, cine bSSFP.AssessmentRetrospective DLR was conducted by applying compressed sensitivity encoding (C‐SENSE) acceleration to systematically undersample fully sampled k‐space cine bSSFP acquisition data over an acceleration/undersampling factor (R) considering a range of 2 to 8. Quality imperceptibility (QI) measures, including structural similarity index measure, were calculated using images reconstructed from fully sampled k‐space as a reference. Image quality, including contrast and edge definition, was evaluated for diagnostic adequacy by three readers with varying levels of experience in cardiac MRI (>4 years, >18 years, and 1 year). Automated DL‐based biventricular segmentation was performed commercially available software by cardiac radiologists with more than 4 years of experience.Statistical TestsTukey box plots, linear mixed effects model, analysis of variance (ANOVA), weighted kappa, Kruskal–Wallis test, and Wilcoxon signed‐rank test were employed as appropriate. A P‐value <0.05 was considered statistically significant.ResultsThere was a significant decrease in the QI values and edge definition scores as R increased. Diagnostically adequate image quality was observed up to R = 5. The effect of R on all biventricular volumetric indices was non‐significant (P = 0.447).Data ConclusionThe biventricular volumetric indices obtained from the reconstruction of fully sampled cine bSSFP acquisitions and DLR of the same k‐space data undersampled by C‐SENSE up to R = 5 may be comparable.Evidence Level3Technical EfficacyStage 1