Clinical Usefulness of Dual-Energy Cardiac Computed Tomography in Acute Coronary Syndrome Using a Dual-Layer Spectral Detector Scanner

Abstract

An 80-year-old woman visited a local hospital because of exertion-induced chest discomfort that lasted several minutes. Although no significant ST-segment changes were observed in an ECG, her troponin-I levels were high. Thus, she was suspected of having ischemic heart disease and was transferred to our university hospital. She had a history of hypertension and was taking antihypertensive drugs, but there had been no chest symptoms. She had no symptoms at the time of visit, no abnormality in her vital signs, and no abnormal findings on physical examination. An ECG obtained after admission revealed no ST-segment changes (Figure 1). Transthoracic echocardiography showed good left ventricular systolic function and no wall motion abnormality. All cardiac enzyme levels were normal, except for the troponin-T level (0.368 ng/mL). We considered acute coronary syndrome or cardiomyopathy and decided to perform imaging evaluations. She underwent cardiac computed tomography (CT) imaging using a dual-layer spectral detector CT (IQon Spectral CT; Philips Healthcare, Best, The Netherlands). Standard coronary CT angiography was performed with intravenous infusion of 550 mg iodine/kg of iodinated contrast medium (iodine 370 mg/mL) for a period of 20 s. After coronary CT angiography, late iodine enhancement (LIE) imaging was performed 8 minutes after the contrast injection. Coronary CT angiography showed severe stenosis of the first diagonal branch (Figure 2A). For more …