Fully personalized contrast injection optimized for weight and tube voltage in low-dose high-pitch coronary CT angiography.

BACKGROUND

To evaluate the performance of a fully individualized, weight- and tube voltage-tailored contrast media injection protocol (MINDS-CAD) for high-pitch coronary CT angiography (CCTA).

METHODS

This IRB-approved, single-center study included 112 patients undergoing clinically indicated CCTA using third-generation dual-source CT. Fifty-six patients were scanned with the MINDS-CAD protocol, which adapts contrast delivery rate (DR, range: 1.7-9.7 mL/s) and contrast volume (CV, range: 23-97 mL) based on body weight and automatic tube voltage selection, creating 56 pairs of CV and DR and uses high-pitch scanning. Fifty-six matched controls underwent CCTA with an institutional standard protocol (retrospective spiral scan, CV, range: 50-80 mL; DR, range: 3.2-5.0 mL/s). Objective image quality was assessed via coronary artery attenuation (HU) in proximal and distal segments. Subjective image quality was graded on a four-point scale (4: excellent), and multiple linear regression was used to identify predictors of coronary attenuation. Dose-length-product (DLP) was compared between cohorts.

RESULTS

Groups were matched for age, BMI, and heart rate (all p > 0.05); over 60 % were obese (BMI ≥ 30 kg/m2). Coronary attenuation was higher with MINDS-CAD (391.1 ± 88.1 HU vs. 305.6 ± 103.1 HU, p < 0.001). Subjective quality was superior (4 [IQR: 3-4] vs. 3 [IQR: 3-3], p < 0.001), with fewer poor-quality scans (Likert 1, 3.5 % vs. 8.8 %) in the MINDS-CAD cohort. In the standard group, BMI and tube voltage predicted attenuation (β = -7.998 and -2.864; p < 0.001), whereas in the MINDS-CAD group, neither was predictive (p = 0.411). Most importantly, MINDS-CAD achieved superior image quality in a matched cohort while considerably lowering radiation dose (90 ± 50 mG•cm vs 576 ± 386 mG•cm, p < 0.001).

CONCLUSION

A fully individualized, weight- and tube voltage-tailored contrast protocol achieved more consistent coronary attenuation and superior image quality. These results, demonstrated in a predominantly obese cohort, highlight the robustness of the protocol and provide a framework for reliable low-dose, high-pitch CCTA across challenging patient populations.