A Heart Rate-Dependent Protocol of “One-Stop” Computed Tomography Angiography of Coronary Combined with Pulmonary Arteries Reduces the Dosages of Contrast Agent

BACKGROUND: The personalized, heart rate-dependent computed tomography angiography (CTA) protocol can reduce the use of contrast medium (CM) and the radiation dose. This is especially beneficial for patients with CTA of coronary combined with pulmonary arteries. PURPOSE: To evaluate the feasibility of low CM in one-stop coronary and pulmonary arterial CTA tailored by patients’ heart rate. MATERIAL AND METHODS: 94 patients set to undergo CTA of coronary combined with pulmonary arteries with one-stop scans. Patients were prospectively randomized into two groups: For group A (n = 47), the timing of the scans was determined according to the patient’s HR using 30 mL CM; For group B (n = 47), in which the routine bolus tracking was applied by setting the ascending aortic threshold of 80 HU with 70 mL CM, scans were performed simultaneously. RESULTS: Compared with group B, group A had slightly higher computed tomography (CT) value and image quality of pulmonary artery (CT value: group A 484.7HU; group B 457.9HU; t = 2.446, P = .016; image quality: χ2 = 8.292, P = .016), but in coronary artery wasn’t statistically different between two groups(image quality: χ2 = 2.516, P = .642). CONCLUSION: The heart rate-dependent CM injection protocol can greatly reduce the use of CM, simplify the work-flow, and may obtain comparable or even better image quality compared with the routine bolus tracking.