Inline automatic quality control of 2D phase‐contrast flow MRI for subject‐specific scan time adaptation.

Purpose: To develop an inline automatic quality control to achieve consistent diagnostic image quality with subject‐specific scan time, and to demonstrate this method for 2D phase‐contrast flow MRI to reach a predetermined SNR. Methods: We designed a closed‐loop feedback framework between image reconstruction and data acquisition to intermittently check SNR (every 20 s) and automatically stop the acquisition when a target SNR is achieved. A free‐breathing 2D pseudo‐golden‐angle spiral phase‐contrast sequence was modified to listen for image‐quality messages from the reconstructions. Ten healthy volunteers and 1 patient were imaged at 0.55 T. Target SNR was selected based on retrospective analysis of cardiac output error, and performance of the automatic SNR‐driven "stop" was assessed inline. Results: SNR calculation and automated segmentation was feasible within 20 s with inline deployment. The SNR‐driven acquisition time was 2 min 39 s ± 67 s (aorta) and 3 min ± 80 s (main pulmonary artery) with a min/max acquisition time of 1 min 43 s/4 min 52 s (aorta) and 1 min 43 s/5 min 50 s (main pulmonary artery) across 6 healthy volunteers, while ensuring a diagnostic measurement with relative absolute error in quantitative flow measurement lower than 2.1% (aorta) and 6.3% (main pulmonary artery). Conclusion: The inline quality control enables subject‐specific optimized scan times while ensuring consistent diagnostic image quality. The distribution of automated stopping times across the population revealed the value of a subject‐specific scan time. [ABSTRACT FROM AUTHOR]