Coronary Artery Computed Tomography Scanning

A 46-year-old woman with diabetes mellitus and a body mass index of 32 kg/m2 reports repeated episodes of chest pain after moderate activity. single photon emission computed tomography myocardial perfusion imaging demonstrates no electrocardiographic (EKG) abnormalities and a small fixed perfusion defect in the posterior left ventricle. Prospectively EKG-triggered coronary CT angiography (CCTA), performed with a radiation dose of 3.5 mSv, demonstrates unremarkable coronary arteries with no evidence of stenosis or atherosclerosis (Figure 1).Figure 1. Unremarkable coronary CT angiography study with no evidence of stenosis or atherosclerosis. Cx indicates circumflex artery; D1, first diagonal; LAD, left anterior descending; LM, left main; OM1, first obtuse marginal; and RCA, right coronary artery.A 63-year-old man with treated hypertension and hyperlipidemia experiences diffuse chest pain and shortness of breath after a long distance flight. Catheter angiography 2 years earlier was normal. At emergency department arrival, his EKG demonstrates no signs of myocardial injury. Cardiac troponin I is 0.04 ng/mL. An EKG-synchronized acute chest pain CCTA examination demonstrates extensive noncalcified plaque of the mid left anterior descending coronary artery causing severe stenosis with signs of acute myocardial hypoperfusion in the anterior and apical left ventricle (Figure 2). The patient undergoes successful revascularization with a drug eluting stent.Figure 2. Coronary CT angiography examination ( A–C ) demonstrates extensive noncalcified plaque of the mid left anterior descending coronary artery causing severe stenosis (arrows) with signs of acute myocardial hypoperfusion in the anterior and apical left ventricle (arrowheads). The obstructive lesion is confirmed by cardiac catheterization ( D ).CCTA has left the early stages of clinical evaluation and matured into a robust diagnostic technique in both elective and emergent settings. Technological innovations are continuously improving the diagnostic performance and decreasing the radiation dose associated with this test. In this Clinician Update, we provide an updated summary on the state-of- …