Abstract
Background: The aim of the present study was to assess semi-quantification of myocardial perfusion using adenosine triphosphate (ATP)-stress myocardial perfusion computed tomography (MPCT) in patients with coronary artery disease (CAD).Methods and Results: Seventeen patients with CAD underwent ATP-stress MPCT, stress myocardial perfusion scintigraphy (MPS) and coronary angiography (CAG). With ATP loading (0.16mg·kg-1·min-1, 5min) and slow infusion of contrast medium (2ml/s, 100ml), stress images were acquired using prospective electrocardiogram-gated 64-slice CT. Stress MPCT images were analyzed according to the transmural perfusion gradient (TMPG; difference between subendocardial and epicardial attenuation, divided by wall thickness; Hounsfield units [HU]/mm) per segment, and summed TMPG was compared with those of stress MPS and CAG per territory and patient, respectively. There were 36 CAG-proved stenotic vessels in 51 (17×3) territories. There were significant correlations between TMPG and MPS stress score per segment, per territory and per patient, respectively (P<0.05). Summed TMPG in territories with and without >70% coronary stenosis was 32.3HU/mm (-1.9~90.9) and 14.5HU/mm (-5.6~38.4; P<0.05). For detecting coronary artery stenosis, sensitivity, specificity, positive and negative predictive values using the summed TMPG were 72%, 87%, 93% and 57%, in comparison with summed MPS (64%, 73%, 85%, and 46%).Conclusions: Semi-quantification of myocardial perfusion using TMPG has great potential to evaluate the severity of myocardial ischemia, similarly to MPS score. (Circ J 2011; 75: 1905-1912)
