Coronary computed tomography angiography with prospective electrocardiography triggering: a systematic review of image quality and radiation dose

Abstract

Singapore Med J 2013; 54(1) : 15 R ev iew A r tic le INTRODUCTIONCoronary computed tomography angiography (CCTA) has been widely used as a valuable diagnostic imaging modality for the noninvasive assessment of coronary artery disease (CAD). It has become a reliable and accurate modality to assess the coronary arteries of patients with suspected CAD.(1) Previous studies have found that retrospective electrocardiography (ECG)-gated CCTA provides high sensitivity (range 86%-99%) and specificity (range 89%-100%) for coronary artery stenosis, and also results in high negative predictive values (NPVs; range 96%-99%).(2,3)Prospective ECG-gated CCTA also promises high sensitivity (range 93.7%-100.0%), specificity (range 82.7%-97.0%) and NPV (range 95%-98%) in the assessment of CAD. (2,3) Although high diagnostic accuracy is achieved with both retrospective and prospective ECG-gated CCTA for detecting CAD (Fig. 1), the radiation doses associated with these two cardiac examinations are significantly different due to the different approaches used for coronary artery scanning.It is well known that CCTA with retrospective ECG gating leads to high radiation doses of up to 31.4 mSv since volumetric data of the heart is acquired during continuous scans in this modality, although only a portion of the data is used for reconstruction. (4,5) In contrast, with exposure taking place at selective phases of the cardiac cycle in patients with low and regular heart rate, prospective ECG triggering is associated with very low radiation doses, which indicates a significant reduction in effective doses of up to 87%. (6) Several studies that used prospective ECG-gated CCTA have reported significantly reduced radiation doses. (7)(8)(9)(10)(11)(12) However, the diagnostic image quality of prospective triggering in the assessment of coronary arteries or CAD has not been systematically studied. Therefore, the purpose of this study was to investigate previous studies that assessed the coronary artery using prospective ECG-triggered CCTA for the detection of CAD, in terms of image quality and radiation dose via a systematic review of the current literature. METHODS Literature searchA ABSTRACT The purpose of this study was to perform a systematic review of the diagnostic accuracy, image quality and radiation dose of prospective electrocardiography (ECG)-triggered coronary computed tomography angiography (CCTA). We searched databases containing studies of CCTA that used prospective ECG-triggering between 2008 and 2011. The effective dose and image quality reported in each study were analysed and compared between the types of multislice CT scanners. We identified 23 studies through this search, with mean assessable coronary segments and effective dose at 96.8% (95% confidence level [CI] 83%, 100%) and 3.6 mSv (95% CI 2.9, 4.3 mSv), respectively. Both quantitative and qualitative assessments of image quality indicated that image quality was achieved in studies using prospective ECG-triggered CCTA, regardless of the type of CT scanners. The pooled es...

Diagnostic performance of low-radiation-dose and low-contrast-dose (double low-dose) coronary CT angiography for coronary artery stenosis

“…There was no significant difference in the IQ between double low- and routine-dose groups, and the image qualifying rate of these 2 groups were higher than the international level (96.8%). [ 20 , 21 ] In the routine-dose group, incorrect diagnosis was due to the dense calcification in 18 segments (64.3%), which was the cause in 17 segments (63%) for the double low-dose group. Obviously, dense calcification represented the primary cause for misdiagnosis.…”

Clinical practice recommendations on lipoprotein apheresis for children with homozygous familial hypercholesterolemia: an expert consensus statement from ERKNet and ESPN

“…50 Radiation dose and hence repeated CTCA assessment is acceptable with the latest generation of CT-scanners. 60 In children, CTCA may result in a median effective dose of only 1 mSv when performed by 128-slice dual source CT. 61 CTCA on the latest generation of CT-scanners also enables image acquisition with a high temporal resolution that allows for application in new- borns and children without sedation. 61 If CTCA is not available, one should consider referring patients to the nearest center with such scanner.…”

Low-Dose Radiation Advances in Coronary Computed Tomography Angiography in the Diagnosis of Coronary Artery Disease

“…A systematic review by Menke et al reported a pooled effective dose of 3.5 mSv with prospective triggering, a factor of 3.5 lower than the pooled effective dose of 12.3 mSv with retrospective gating with comparable CCTA image quality and diagnostic accuracy [ 31 ]. Furthermore, prospective ECG-gating allows extra low-dose cardiac imaging with high sensitivity, specificity, negative predictive value, positive predictive value, and accuracy for detecting CAD [ 32 ]. This method, however, reaches its limits with patients with severe arrhythmia since it relies on the prediction of the patient’s next cardiac cycle.…”