Effect of a motion-correction algorithm on motion-related image quality in mid-diastolic CCTA using 320-detector row CT.

Background

Motion artifacts limit coronary CT angiography (CCTA) when mid-diastolic quiescence is short. RR-PQ estimates the low-motion interval available for reconstruction, whereas motion correction may improve image quality without changing cardiac physiology.

Purpose

To primarily evaluate the incremental effect of Clear Motion Cardiac (CMC) compared with half-scan reconstruction and secondarily characterize the probability of diagnostic image quality across RR-PQ values and derive candidate operational RR-PQ values on a 0.24-s/rotation 320-detector row CT system.

Methods

In 1012 consecutive CCTA examinations, paired half-scan and CMC series were reconstructed from identical raw data. Motion was graded A-D (A/B diagnostic). McNemar tests compared paired rates; logistic models estimated diagnostic probability and candidate RR-PQ values.

Results

Diagnostic image quality increased from 841/1012 (83.1%) with half-scan to 939/1012 (92.8%) with CMC (p < 0.0001). Of 171 half-scan failures, 101 were rescued; degradation occurred in 3/1012. Benefit increased with heart rate and was greatest at ≥70 bpm. RR-PQ was strongly associated with the probability of diagnostic image quality; candidate values at 95% probability were 807 ms for half-scan and 739 ms for CMC.

Conclusion

CMC improved diagnostic image quality, especially at higher heart rates and shorter RR-PQ. The derived values may aid workflow planning but are platform- and cohort-specific.