Cardiovasc Imaging Asia.  2018 Jul;2(3):123-128. 10.22468/cvia.2017.00192.

Determining Whether Tube Voltages and Contrast Flow Rates have an Impact on a Test Bolus-Based Contrast-Enhancement-Prediction Algorithm during Coronary CT Angiography

• Zhu X
• Yu Y
• Tang L
• Zhang H

• KMID: 2524872
• DOI: http://doi.org/10.22468/cvia.2017.00192

Abstract

Objective
To assess whether tube voltages and contrast flow rates have an impact on a test bolus (TB)-based contrast-enhancement-prediction (CEP) algorithm during coronary computed tomographic angiography (CCTA).
Materials and Methods
A total of 188 anonymized CCTA examinations following TB scans were collected. During TB, a tube voltage of 100 kV and contrast flow rate of 3.5 mL/s were applied for Group 1 and 120 kV and 4.5 mL/s for Group 2. True aortic enhancements were extracted with a region of interest at the ascending aorta (AAo). TB signals and group information were used as independent variables in a stepwise linear regression analysis to predict aortic enhancement. For each patient, the errors in predicted aortic enhancements were calculated.
Results
Time to peak enhancement in the AAo (PT _AAo) and peak enhancement in the descending aorta (PE _DAo) during the TB study had significant correlations with AAo (AAo= -125.627+1.619×PE _DAo+16.236×PT _AAo r=0.782, p<0.001). The CEP algorithm without group information presented a minor systemic underestimation in Group 1 [-8 Hounsfield unit (HU)] and an overestimation in Group 2 (8 HU).
Conclusion
The TB-based CEP of aortic enhancement is feasible. The tube voltages and contrast flow rates during TB scanning were statistically significant, but resulted in a clinical negligible impact on the CEP algorithm.

Keyword

Tube voltage; Contrast agent; Coronary; Computed tomography angiography; Contrast enhancement prediction.