Factors related to diminished accuracy include image quality, the extent of coronary calcification, and body mass index A potential advantage of CCTA over standard functional testing is its very high negative predictive value for obstruc- tive CAD, which can reassure caregivers that providing GDMT and deferring consideration of revascularization con- stitute a sensible strategy. In addition to documentation of stenotic lesions, CCTA can qualitatively visualize arterial remodeling and nonobstructive plaque, including calcified, noncalcified, or mixed plaque.211 216 The presence of nonob- structive plaque has been shown to be helpful to guiding risk assessment and can aid in discerning the etiology of patient symptoms.211,215,216 CT information has been correlated with functional stress testing.203,204,215 Not every obstructive lesion produces ischemia, and ischemia can be present in the absence of a significant stenosis in epicardial vessels, which results in discordance between anatomic imaging with CCTA and functional stress testing. Several series have reported the positive predictive value of an anatomic lesion detected on CCTA to range from 29% to 44% when ischemia on a stress study is used as a reference standard.203,204 The evidence on concordance, however, remains incomplete, with current research showing the highest degree of concordance between ischemia and mixed plaque. Because the presence of signif- icant calcification often can preclude the accurate assessment of lesion severity or cause a false positive study, CCTA should not be performed in patients who have known exten- sive calcification or a high risk of CAD. 2.2.4.2. 