Comparison of image quality and radiation dose between prospectively ECG-triggered and retrospectively ECG-gated CT angiography: Establishing heart rate cut-off values in first-generation dual-source CT

Abstract

Objective:To evaluate radiation dose and image quality of prospectively electrocardiography (ECG)-triggered and retrospectively ECG-gated coronary computed tomography (CT) angiography and to establish cut-off values of heart rates (HRs) for each technique in firstgeneration dual-source CT.Methods:A total of 200 consecutive patients with suspected coronary artery disease were accepted into the study. Patients were selected randomly for each technique (prospective triggering group n=99, mean age 55.85±10.74 and retrospective gating group n=101, mean age 53.38±11.58). Two independent radiologists scored coronary artery segments for image quality using a 5-point scale. Also, attenuation values of each coronary artery segment and dose-length product values were measured. For each technique, cut-off HR values were determined for the best image quality.Results:Mean image quality scores and attenuation values were found to be higher in the prospective triggering group (p<0.05). Mean radiation dose was 73% lower for the prospective triggering group (p<0.01). The cut-off HR values for good image quality scores were ≤67 beats per minute (bpm) and ≤80 bpm for the prospective triggering and retrospective gating groups, respectively (p<0.05). Increased HR (≥68 and ≥81 bpm, respectively) had negative effects on image quality (p<0.05).Conclusion:The prospective ECG triggering technique has better image quality scores than retrospective ECG gating, particularly in patients who have an HR of less than 68 bpm. Also, a 73% radiation dose reduction can be achieved with prospective ECG triggering. In patients with higher heart rates, retrospective ECG gating is recommended.

Image quality and radiation dose of dual source high pitch computed tomography in pediatric congenital heart disease

“…In accordance with other similar studies, we found a negative correlation between heart rate and the image quality score (r = − 0.43, p = 0.02), confirming that a lower heart rate leads to an improved image score 25 , 26 . CNR also, unsurprisingly, correlated with image quality (r = 0.63, p = < 0.001).…”

Application of double low dose combined low flow injection in coronary dual‐source coronary computed tomography angiography

“…It had the advantage of high sensitivity and specificity as well as negative predictive value in comparison with invasive CCTA which was served as the standard of reference for the detection of CAD due to its high temporal resolution and spatial resolution. 8,9 More importantly, these following scanning parameters DOI: 10.1111/echo.14036 C A R D I A C C T S e c t i o n E d i t o r s -M i c h a e l T u r n e r , M D a n d N e e r a j J a i n , M D Application of double low dose combined low flow injection in coronary dual-source coronary computed tomography angiography | 1443 TANG including the tube voltage, the contrast medium volume, and velocity of flow injection were closely associated with the radiation dose. For example, Ko et al 7 reported that the average radiation dose for retrospective ECG-triggering was 10.7 ± 2.70 mSv, while the mean radiation dose was 3.83 ± 0.84 mSv for prospective ECG-gating, suggesting that CCTA performed with prospective ECG-triggering had less effective radiation dose as compared to retrospective ECG-triggering.…”

“…Moreover, the prospective ECGtriggered CCTA was considered as the critical technique to reduce effective radiation dose, as a great deal of studies showed that it could acquire high-quality images in the case of relatively low radiation dose. 8,9 More importantly, these following scanning parameters DOI: 10.1111/echo.14036…”

Gender based lung cancer risks for symptomatic coronary artery disease patients undergone cardiac CT

“…For the CTCS cases of present study, use have been made of prospective ECG gating-based tube current modulation, with the scan performed by step-and-shoot acquisition, a situation in which the x-ray tube is energized only during the cardiac phase. Use of ECG-gating has been claimed to decrease radiation dose to the patient by approaching 45% [ 32 ] compared to CCTA examination carried out without ECG-gating [ 33 ]. Mean organ doses to the thyroid, esophagus, lungs, liver, stomach, heart, and other organs have been generated using CT-EXPO dosimetry.…”