Abstract 4209: Adenosine Triphosphate Stress Myocardial Perfusion CT in Comparison with SPECT and MRI
Based on the contrast dynamics and our previous study that multi-slice spiral computed tomography (CT) could describe myocardial ischemia as hypo-perfusion area (HPA) during adenosine triphosphate (ATP) stress test, the ATP stress myocardial perfusion CT was simply arranged and tested in clinical use. This study had institutional review board approval and patients gave informed consent. Eighteen patients with coronary artery disease (CAD) (8 female; mean age, 67 years) underwent ATP stress 16-slice/64-slice CT and 201-Thallium single photon emission computed tomography (SPECT), and coronary angiography (CAG), respectively. Twelve patients underwent gadolinium magnetic resonance imaging (MRI) as required. The ATP-stress perfusion CT was composed as follows; the stress image was acquired without bolus tracking after the contrast-injection (370 mg-iodine/ml, 100 ml, 2 ml/min) in 3 minutes later during intravenous ATP (0.16 mg/kg/min) 5-minutes infusion, and the late image was acquired without additional contrast administration after 15 minutes from the stress image. Semi-quantitative assessment of myocardial perfusion was performed with the CT-attenuation based color coded images (hot color as hyper-enhanced; cold color as hypo-enhanced). The HPA of perfusion CT and early defect (ED) of SPECT in each stress image, late iodine-enhancement (LIE) and gadolinium enhancement (LGE) in each late image were compared, respectively. Eighteen patients had 54 (18*3) coronary territories and 30 stenoses probed by CAG. Perfusion CT described 39 HPAs and SPECT described 29 EDs in the stress images. The agreement between perfusion CT and SPECT was 74% (40/54, p<0.05). CAG probed 21 stenoses in 27 HPA(+)/ED(−) matched territories, 9 stenoses in 12 HPA(+)/ED(−) mismatched territories, no stenosis in 15 HPA(−) territories, respectively. Perfusion CT described 5 LIEs and MRI described 7 LGEs in the late images. The agreement between perfusion CT and MRI was 89% (32/36, p<0.05). The ATP stress myocardial perfusion CT has wide utilities in robust assessment of myocardial ischemia and myocardial infarction (late enhancement) just like SPECT and MRI in patients with CAD.