ECG-gated chest CT angiography with 64-MDCT and tri-phasic IV contrast administration regimen in patients with acute non-specific chest pain

The purpose of this study was to evaluate chest CTA protocol using retrospective ECG-gating and triphasic IV contrast regimen for comprehensive evaluation of patients with acute non-specific chest pain. ECG-triggered dose modulation was used with a 64-MDCT scanner in 56 non-critically ill patients with acute nonspecific chest pain using triphasic IV regimen: 50 ml contrast followed by 50 ml 60% contrast/saline and 30 ml normal saline. Lungs, aorta, pulmonary and coronary arteries were graded on a 5-point scale (5, best). Aorta and pulmonary artery attenuation was measured and three coronary artery groups were evaluated. Comparison with invasive coronary angiography was obtained in nine patients on a per segment (16 total) basis. Dosimetry values were obtained. Studies were satisfactory in all patients (score >3). Aorta and pulmonary artery attenuation was >200 HU in 90.5%. Lung or pleura, non-cardiac vascular and coronary arteries disease were detected in 20, 11 and 16 patients, respectively. Median coronary angiography (grade 5) was significantly higher than acceptable for diagnosis grade 4 (p < 0.001). Per segment, weighted kappa statistic was 0.79 indicating substantial agreement with catheter angiography (p<0.001). Average DLP was 1,490 ± 412 mGy-cm. Gated 64-MDCT angiography with triphasic IV contrast is a robust multipurpose technique for patients with acute non-specific chest pain. (orig.)