Is the "triple rule-out" study an appropriate indication for cardiovascular CT?

There is interest in using the fast volume coverage of 64-slice cardiovascular CT angiography (CCTA) in patients presenting with undifferentiated acute chest pain to simultaneously evaluate the coronary arteries, thoracic aorta, and pulmonary arteries during a single breathhold, the so-called "triple rule-out." However, it is not clear whether the triple rule-out study is an appropriate indication for cardiovascular CCTA. Initial studies suggest that performing a triple rule-out protocol to comprehensively evaluate patients with acute chest pain presenting to the emergency department (ED) is feasible and that quantitative parameters of image quality may be comparable to the conventional, dedicated coronary and pulmonary CTA protocols. Recent data also suggest that a triple rule-out protocol has the potential to identify a subset of patients presenting with acute chest pain who can safely be discharged from the ED. In addition, new scanner technology has also reduced the contrast and radiation doses necessary for such an examination. However, despite these early encouraging results, randomized control trials designed to determine whether this protocol is safe, cost-effective, and improves clinical decision making are necessary before routine implementation of such an examination can be justified.