Feasibility of Low-Dose Contrast Medium High Pitch CT Angiography for the Combined Evaluation of Coronary, Head and Neck Arteries

Purpose To evaluate the image quality and radiation dose of combined heart, head, and neck CT angiography (CTA) using prospectively electrocardiography (ECG)-triggered high-pitch spiral scan protocol, compared with single coronary CTA. Materials and Methods 151 consecutive patients were prospectively included and randomly divided into three groups. Group 1 (n = 47) underwent combined heart, neck, and head CTA using prospectively ECG-triggered high-pitch spiral (Flash) scan protocol with a single-phase intravenous injection of iodinated contrast and saline flush; Group 2 (n = 51) underwent single coronary CTA with Flash scan protocol; and Group 3 (n = 53) underwent single coronary CTA with prospective sequence scan protocol. All patients were examined on a dual source CT (Definition FLASH). The image quality was determined for each CT study. Results Patients of scanning protocol Group 1, 2, and 3 showed no significant differences in age, sex, heart rates, and BMI. Evaluation of coronary artery image quality showed comparable results in the three scanning protocol groups on a per patient-based analysis. In group 1, image quality was found to be sufficient to be diagnostic in all arterial segments of carotid arteries. The mean dose-length product (DLP) for group 1 was 256.3±24.5 mGy×cm and was significantly higher in comparison with group 2 (93.4±19.9 mGy×cm; p < 0.001). However, there was no significant difference of DLP between group 1 and group 3 (254.1±69.9 mGy×cm). Conclusions The combined heart, neck, and head arteries scan using prospectively electrocardiography (ECG)-triggered high-pitch spiral scan protocol in 1 single examination resulted in an excellent opacification of the aorta, the carotid arteries, and the coronary arteries and provided a good image quality with low radiation dose.