Purpose: To prospectively evaluate the enhancement of coronary, pulmonary, and thoracic aortic vasculature by using biphasic single-acquisition 64-section computed tomographic (CT) angiography and to prospectively evaluate if differences in right side of the heart and coronary venous enhancement interfere with interpretation of coronary arteries.
Materials and methods: With internal review board approval and HIPAA compliance, 50 patients (16 men, 34 women; mean age, 51.5 years; range, 30-75 years) with atypical chest pain were referred from the emergency department and were imaged with a 64-section CT scanner after premedication with oral atenolol and/or intravenous metoprolol. Thoracic CT angiography with retrospective gating was subsequently performed with a single biphasic injection of 130 mL of iso-osmolar contrast material (100 mL at 5 mL/sec and 30 mL at 3 mL/sec) in caudal-to-cranial acquisition. Coronary, aortic, and pulmonary arterial attenuation values were obtained. Coronary venous and right atrial enhancement were evaluated to assess whether there was interference with coronary artery evaluation. A two-tailed Friedman test was used to evaluate differences among segments within each artery.
Results: Mean coronary arterial, pulmonary arterial, and aortic attenuation values were significantly higher than the 250-HU threshold (P < .05). Mean pooled coronary arterial (288.9 HU +/- 64.8), pulmonary arterial (316.4 HU +/- 79.9), and aortic (329.9 HU +/- 63.3) attenuation values were significantly higher than the 250-HU threshold (P < .0001). Coronary venous enhancement did not affect depiction or interpretation of coronary arteries. Right atrial streak artifact focally traversed the right coronary artery in only one study.
Conclusion: The aforementioned thoracic CT angiographic protocol provides enhancement of coronary, aortic, and pulmonary vasculature in a single breath hold without interference from right side of the heart streak artifact or coronary venous enhancement.