Rationale and objectives: The purpose of our study was to compare test bolus techniques using undiluted or diluted contrast material for their ability to predict aortic enhancement on coronary computed tomographic angiography (c-CTA) images.
Materials and methods: We divided 200 consecutive patients who underwent c-CTA on a 64-MDCT scanner into two groups. In group A (n = 100), we used a test bolus of undiluted contrast material and in group B (n = 100), the contrast material was diluted. The injection volume was body weight × 0.2 (contrast material 100%) in group A and body weight × 0.7 (contrast material 30%, saline 70%) in group B. We then compared the CT number in the ascending aorta on c-CTA images obtained with undiluted and diluted contrast media to the CT number on c-CTA images.
Results: The mean CT number in the ascending aorta was significantly higher in group B than group A (217.1 vs. 157.4 HU, P < .001). There was a significant difference in the correlation between the CT number of the ascending aorta on c-CTA images and on images acquired with the test bolus using undiluted or diluted test bolus (P < .001). In group B, the correlation had a strong positive linear relationship (r = 0.72, P < .001), whereas in group A the positive linear relationship was weak (r = 0.36).
Conclusions: The test bolus with diluted contrast material was useful for predicting aortic enhancement before c-CTA scanning.
Keywords: Test bolus technique; aortic enhancement; contrast material; coronary CTA.
Copyright © 2014 AUR. Published by Elsevier Inc. All rights reserved.