The application value of sinogram affirmed iterative reconstruction (SAFIRE) algorithm in the coronary computed tomography angiography(CCTA) with the tri-low scheme of dual source CT / 中华放射医学与防护杂志

ABSTRACT

Objective To investigate the application value of sinogram affirmed iterative reconstruction (SAFIRE) algorithm in the coronary computed tomography angiography(CCTA) with tri-low scheme (low tube voltage,low dose contrast agent,low flow rate injection) of the dual-source CT.Methods Totally 120 patients with body mass index (BMI) of 18.6 to 24.9 kg/m 2,heart rate ＜ 65 b/min were selected continuously and the contrast agent iohexol (350 mgI/ml) was used.The patients were divided equally into two groupsFBP group,using 120 kV tube voltages,contrast media dose of 0.9 ml/kg,and injection rate of 5.0 ml/s to carry out prospective ECG-trigger scanning,and image reconstruction based on filtered back projection (FBP) algorithm;SAFIRE group,using 80 kV tube voltage,contrast media dosage 0.7 ml/kg,injection rate of 3.5 ml/s to carry out prospective ECG-trigger high-pitch scanning,and iterative reconstruction technique.CT values of enhanced images and noise of two groups of arterial lumen and left ventricular bottom muscle were measured,and the signal-to-noise ratio (SNR) and contrast to noise ratio (CNR) were calculated.The method of double blind was used to evaluate coronary artery in 4-point scale (1 =non-diagnostic).The average volume CT dose index (CTDIvol) and the dose length product (DLP) for each patient were recorded and the effective radiation doses were calculated.Results The difference in the CT values,image noise,SNR,CNR between the two groups was not statistically significantly(P ＞ 0.05).The effective dose in SAFIRE group was (0.39 ± 0.02) mSv significantly lower than that in FBP group of (4.99 ± 1.36) mSv (t =26.31,P＜0.01).Conclusions For the patients with body mass index (BMI) 18.6 to 24.9 kg/m2,HR ＜ 65 b/min,the application of prospective ECG-trigger high pitch tri-low scheme combined with the iterative reconstruction algorithm in dual-source CT coronary angiography,can obtain the qualified image with lower radiation dose.