Coronary computed tomography angiography (CTA) offers a non-invasive method to detect coronary plaque and stenosis. However, to date, CTA has been most useful as a method of ruling out coronary artery disease (CAD) among patients with low to intermediate pretest probability of significant CAD. The reduced specificity of CTA for detecting physiologically significant stenosis is a known limitation of this technique, particularly since some patients require additional functional testing following CTA. Therefore, intense interest has focused on the development of methods to determine the functional significance of anatomical lesions identified by CTA. This article will discuss two emerging methods: stress myocardial perfusion imaging using CT, or CT perfusion, and computer simulation of fractional flow reserve.