Multiple center study about the reliability of the low-dose dual-source CT coronary angiography in the step-and-shoot mode / 中华放射学杂志

ABSTRACT

Objective To investigate the accuracy of low-dose dual-source computed tomography (DSCT) coronary angiography in the step-and-shoot (SAS) mode for the diagnosis of coronary artery stenosis in comparison with conventional coronary angingraphy (CCA).Methods Prospective multiple-center study, 46 patients[mean age(58±9) years;bedy mass index(BMI) (25±3) kg/m2]underwent both DSCT in the SAS mode and CCA within 14 days.The inclusion criteria for contrast-enhanced CT (1) heart rate less than 65 times/rain (bpm).(2) regular sinus rhythm, heart rate fluctuations within the range of 6 bpm. (3) holding breath well, breath-hold time is about 12-15 s.The exclusion criteria(1) allergy to iodinecontaining contrast medium, nephropathy (serum creatinine level 120 μmol/L), heart failure and serious arrhythmias.(2) patients with coronary stents or bypass grafts.(3) heart rate can not be controlled very well (4)the patient could not take nitroglycerin.(5)BMI 30 kg/m2.(6) other heart disease carcliomyopathy, valvular disease etc.Sensitivity, specificity, negative (NPV) and positive predictive value (PPV) were determined with CCA as standard of reference.The Kappa value between the two modalities and the two observers was calculated.Radiation dose values were measured.Results Mean heart rate during scanning was (61±6)bpm.99.19% (614/619) coronary segments were depicted with a diagnostic image quality. The vessel-based sensitivity, specificity, PPV, and NPV for the diagnosis of coronary artery stenosis were 96.2% (75/78), 88.2% (60/68), 90.4% (75/83), and 95.2% (60/63), respectively.The Kappa value between the two modalities was 0.848 (P=0.000).The mean effective dose of the SAS-CTCA was (2.95± 0.96) rosy(1.26-4.32 mSy).Conclusion In selected patients, DSCT coronary angiography in the SAS mode have good image quality, which allows for the accurate diagnosis of coronary stenosis at a low radiation dose.