a: Results of overall image quality assessments for the conventional reconstruction and the proposed data-driven reconstruction from reader 1, reader 2, reader3, and their average scores (from left to right). Grading features include the perceived noise, contrast, sharpness, artifacts, and confidence of detecting liver lesions. Statistically different results with P < 0.05 were marked with (*). Statistically different results with P < 0.005 were marked with (**). Error bars are standard error of the mean. b: Comparison of the total online computation time for the proposed method (dark gray) and conventional reconstruction (light gray). An average reduction factor of 2.1 in computation time was achieved with the proposed method.