Birinci Jenerasyon Çift Tüplü BT Kullanılarak Prospektif ve Retrospektif EKG Tetikleme Yöntemleriyle Elde Olunan Koroner BT Anjiyografi Tetkiklerinin Karşılaştırılması

Abstract

The purpose of this study is to evaluate radiation dose and image quality of prospective triggering and retrospective electrocardiography (ECG) gated coronary computed tomography (CT) angiography and to establish cut-off values of heart rates (HR) for each technique in first generation dual source CT. 200 patients whom have suspected coronary artery disease, were scanned for our prospective study. Patients were selected randomly for each tehnique (prospective triggering group n=99; 53M, mean age 55.85+/-10.74 and retrospective gating group n=101; 52M, mean age 53.38+/-11.58). Two independent radiologist scored coronary artery segments for image quality with using a five-point scale. Also attenuation values of each coronary artery segment and dose length product (DLP) values were measured. For each technique, cut-off HR values were determined for best image quality. Mean image quality scores and attenuation values were found to be higher in prospective group (P<0.05). Mean radiation dose was 72% lower for prospective group (P<0.01). The cut-off HR values to get a better quality score were ≤67 beat per minute (bpm) and ≤80 bpm for prospective and retrospective group, respectively (P<0.05). In case of increased HR (≥68 and ≥81 bpm respectively), there were negative effect on quality (P<0.05). In conclusion, prospective ECG triggering technique has better image quality scores than retrospective ECG gating, particularly in patients who have HR <68 bpm. Additionally, we recommend to decrease HR to ≤80 bpm before retrospective ECG gating coronary CT angiography to preserve image quality.