Evaluation of Image Quality of Compressed Sensing Magnetic Resonance Images

The aim of the study was to compare the image quality of reconstructed images using the 3D T1 variable flip angle (CUBE) sequence with and without compressed sensing (CS). A phantom was prepared by diluting the Gadolinium contrast medium with saline at the concentrations of 0, 0.2, 0.6, 1.0, and 4.0 mM. Moreover, images were obtained using the 3D T1 CUBE sequence with and without the use of CS. When CS was used, images were reconstructed at increasing CS factor values (i.e., 1.2, 1.4, 1.6, 1.8, and 2.0), while all other variables were unaltered. Measurements were analyzed using Student's t-tests and ANOVA. Moreover, the SSIM and RMSE estimates were evaluated using the ICY program and the relative SNR errors were quantified. The scan time reduced by up to 1min 35sec from the conventional 3D T1 CUBE sequence (3min 3sec) to 3D T1 CUBE sequence using CS (CS factor=2.0). The SNR values of the conventional 3D T1 CUBE and 3D T1 CUBE sequences using the CS technique were not significantly (p>0.05) different when the CS factors varied from 1.2 to 2.0. Moreover, the estimated SSIM were similar, while the root mean square error (RMSE) values varied when the CS factor varied from 1.2 to 2.0, based on the use of the conventional 3D T1 CUBE sequence. Therefore, the 3D T1 CUBE sequence using the CS technique can achieve an acceptable image quality that is not considerably different from that of the conventional method.