The use of dual and triple rule-out computerized tomography angiography by using diagnostic low-dose contrast material and radiation in acute chest pain.

Background: Triple rule-out computed tomography angiography (CTA) provides imaging of the coronary arteries, pulmonary arteries, and thoracic aorta filled with contrast material (CM) to exclude or diagnose the pathologies of these three systems. Although dual rule-out adapted to exclude aortic and pulmonary pathologies. Iodinated CM may result in contrast-induced nephropathy, which lengthens hospital stay.

Purpose: To compare image quality of dual/triple rule-out CTA by reducing the radiation dose by using relatively high mAs with less contrast material and low kilovoltage without affecting the diagnostic value.

Methods: We acquired standard dual/triple rule-out CTA 120 kilovoltage peak (kVp) with 95 mL contrast material. The low-dose group acquired 80 Kvp with total 60 contrast material. There were 91 patients in the standard-dose group and 88 patients in the low-dose group.

Results: Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated separately. There was no significant difference in CNR values between the two groups in the aorta and pulmonary and coronary arteries; however, a significant difference was found in SNR values. In subjective image quality evaluation, no significant difference was found between the standard- and low-dose patients. The radiation dose was reduced by 63.80% and the contrast material by 31.5% in the low-dose group in comparison to the standard dose.

Conclusion: Our study showed that dual/triple rule-out CTA can be performed with low-dose radiation and low-volume contrast material. Low-dose CTA may be preferred in emergencies situations that patients with borderline renal function tests or the risk group.