Systolic prospectively ECG-triggered dual-source CT angiography for evaluation of the coronary arteries in heart transplant recipients

OBJECTIVES
To assess feasibility, image quality, and radiation dose of prospectively ECG-triggered coronary CT angiography (CTA) in orthotopic heart transplant (OHT) recipients.

METHODS
47 consecutive OHT recipients (40 men, mean age 62.1±10.9 years, mean heart rate 86.3±14.4 bpm) underwent dual-source CTA to rule out coronary allograft vasculopathy in a prospectively ECG-triggered mode with data acquisition during 35% to 45% of the cardiac cycle. Two independent observers blindly assessed image quality on a per-segment and per-vessel basis using a four-point scale (1-excellent, 4-not evaluable). Scores 1-3 were considered acceptable for diagnosis. Multivariate analysis was performed to evaluate differences between image quality scores obtained at different reconstruction intervals. Effective radiation doses were calculated.

RESULTS
671 coronary segments were evaluated. Interobserver agreement on the image quality was ?=0.75. Diagnostic image quality was observed in 93.9%, 95.5% and 93.3% of the segments at 35%, 40% and 45% reconstruction intervals. Mean image quality score was 1.5±0.7 for the entire coronary tree, 1.4±0.7 for the RCA, 1.6±0.8 for the LCA and 1.6±0.7 for the Cx at the best reconstruction interval. Estimated mean radiation dose was 4.5±1.2 mSv.

CONCLUSION
Systolic prospectively ECG-triggered CTA allows diagnostic image quality coronary angiograms in OHT recipients at low radiation doses.

CITATION  Eur Radiol. 2011 Apr 12