Improved image quality using a whole-heart motion correction algorithm in coronary computed tomography angiography

SnapShot Freeze 2 (SSF2) is a second-generation whole-heart motion correction algorithm for coronary computed tomography angiography (CCTA), designed to enhance temporal resolution and reduce motion artifacts. Its performance in detailed coronary segmentation and high-heart-rate scenarios remains underexplored.

In this retrospective study, 120 patients with suspected coronary artery disease underwent CCTA reconstructed using standard, first-generation SnapShot Freeze (SSF1), and SSF2 algorithms. The image quality was assessed via signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and a 5-point Likert scale across the American Heart Association (AHA) 15-segment model. We further examined SSF2's performance in patients with heart rates ≥80 beats per minute (bpm) and analysed correlations between computed tomography-derived fractional flow reserve (CT-FFR), ΔCT-FFR, and myocardial injury biomarkers.

SSF2 significantly improved image quality versus standard reconstruction without motion correction (STND) and SSF1, particularly in high-heart-rate patients and distal segments. SNR and CNR were higher for SSF2 in key coronary territories (eg, left anterior descending artery [LAD] diastole: SNR: 21.8 vs 19.0; CNR: 19.0 vs 17.2). Segments rated increased to 60.0% with SSF2. In patients with heart rates ≥80 bpm, SSF2 maintained superior image quality (55.0% vs 35.0% and 40.0% with STND and SSF1). SSF2-derived CT-FFR values showed strong inverse correlations with Coronary Artery Disease - Reporting and Data System (CAD-RADS) stenosis scores (r=-0.58 to -0.65) and moderate negative correlations with Creatine Kinase -Myocardial Band (CK-MB) and cardiac Troponin I (cTnI) (all P<0.001). ΔCT-FFR correlated positively with stenosis grade and myocardial injury markers (P<0.05).

SSF2 provides superior image quality and physiological assessment capabilities in CCTA, particularly in patients with elevated heart rates. These improvements support its potential for enhancing coronary stenosis evaluation, though further validation against invasive standards is warranted.