The bolus track contrast enhancement protocol for CT pulmonary angiography provides increased enhancement of the pulmonary vessels and aorta and fewer suboptimal scans compared to the test bolus protocol

A retrospective study compared test bolus and bolus track in contrast-enhanced CT pulmonary angiography (CTPA) in terms of vessel enhancement, number of suboptimal scans and radiation dose. The bolus track protocol provided increased opacification of the pulmonary arteries and aorta, a lower suboptimal scan rate and a lower radiation dose, proving that it may be considered the optimal technique for CTPA.