Dual-Source Computed Tomographic Coronary Angiography:Image Quality and Stenosis Diagnosis of Patients with High Heart Rates / 医疗卫生装备

ABSTRACT

Objective To prospectively evaluate the effects of heart rate and heart-rate variability on dual-source computed tomographic coronary image quality in patients with high heart rates,and to determine retrospectively the accuracy of dualsource computed tomographic diagnosis of coronary artery stenosis in the same patients.Methods The image quality and diagnostic accuracy were compared between the normal group of 40 patients whose heart rates exceeded 70 beats/min and the control group of 40 patients whose heart rates were 70 beats/min or slower.Results No statistically significant differences between the groups were found in diagnostic-image quality scores of total segments or of any coronary artery,nor were any significant differences found between the groups in the accurate diagnosis of angiographically significant stenosis.Calcification was the chief factor that affected diagnostic accuracy.In high -heart -rate patients,heart -rate variability was significantly related to the diagnostic image quality of all segments(P=0.001) and of the left circumflex coronary artery(P=0.016).Heart-rate variability more than 5 beats/min most strongly contributed to an inability to evaluate segments in both groups.When heart rates rose,the optimal reconstruction window shifted from diastole to systole.Conclusion The image quality of dual -source computed tomographic coronary angiography at high heart rates enables sufficient diagnosis of stenosis,although variability of heart rates significantly deteriorates image quality.