Low-dose contrast protocol using the test bolus technique for 64-detector computed tomography coronary angiography

Area of Science:

• Cardiovascular imaging
• Radiology
• Medical technology

Background:

• Coronary computed tomography angiography (CTA) is crucial for diagnosing coronary artery disease.
• Optimizing contrast material (CM) usage in CTA is essential for patient safety and reducing costs.
• Traditional CTA protocols may involve higher CM volumes than necessary.

Purpose of the Study:

• To evaluate a low-contrast injection protocol for coronary CTA using a 64-detector scanner.
• To compare the efficacy of a low-dose, short-injection-duration protocol with a conventional protocol.

Main Methods:

• Sixty patients undergoing coronary CTA were randomized into two groups: low-contrast dose (P(low)) and conventional protocol (P(conv)).
• P(low) used 0.7 ml/kg iohexol-350 injected over 9s with a test bolus technique.
• P(conv) used 1.0 ml/kg iohexol-350 injected over 15s with bolus tracking.

Main Results:

• No significant difference in CT attenuation was observed between the low-contrast and conventional protocols in the aorta and coronary arteries.
• The low-contrast protocol significantly reduced the total amount of CM required compared to the conventional protocol (49.7 ± 6.4 ml vs. 57.0 ± 10.1 ml).

Conclusions:

• A low-dose, short-injection-duration protocol with test bolus technique achieves comparable vessel attenuation to standard protocols in 64-detector coronary CTA.
• This optimized protocol offers a significant reduction in contrast material volume without compromising diagnostic image quality.