Image Quality and Reconstruction Intervals of Dual-Source CT Coronary Angiography

Abstract

DSCT coronary angiography provides best image quality for various HRs at 70%. The ECG-pulsing window can be adapted according to the HR while maintaining diagnostic image quality.

Dose levels at coronary CT angiography—a comparison of Dual Energy-, Dual Source- and 16-slice CT

“…However this conventional ECG pulsing algorithm was sensitive to arrhythmia or ectopic heart beats and could let to a mismatch of the interval of the full tube current and the desired reconstruction interval and thus to image quality degradation [16]. Modern ECGpulsing algorithms are able to detect arrhythmia and automatically switch off the ECG pulsing during the ectopic heart beats.…”

“…According to a study of phantom measurements, this decrease in scan time translates into linear decrease in patient dose [22]. Recently, the feasibility of applying ECG pulsing has been shown for DSCT coronary angiography and recommendations have been made for the dynamic selection of the ECG-pulsing window width in relation to the patients heart rate [16]. Following these recommendations, Stolzmann et al reported that despite using wider pulsing windows at higher heart rates, the radiation dose of DSCT decreased as the heart rate increased.…”

“…A variety of techniques have focused on reducing the radiation dose delivered during cCTA by modulating the tube current [16,18]. However this conventional ECG pulsing algorithm was sensitive to arrhythmia or ectopic heart beats and could let to a mismatch of the interval of the full tube current and the desired reconstruction interval and thus to image quality degradation [16].…”

“…However, when prospective ECG-triggering is used data is obtained during only a short and predefined data acquisition window that usually is placed in mid-diastole. Therefore, no information on the global and regional ventricular function or valvular function can be obtained [16,40,41]. In contrast using DECT in every patient a full functional dataset was obtained and documented in the clinical report.…”

“…In group 2 and 3 ECG pulsing for radiation dose reduction was used in all retrospectively ECG-gated cCTA protocols, as previously recommended [16]: with mean heart rates below 60 bpm, full tube current was applied from 60% to 70%, at 61-70 bpm from 60% to 80%, at 71-80 bpm from 55% to 80%, and with heart rates above 80 bpm from 30% to 80% of the RR-interval. Data of helical cCTA were reconstructed with a slice thickness of 0.75 mm, a reconstruction increment of 0.4 mm, and using a soft tissue convolution kernel (B26f) and an algorithm for automatic selection of the cardiac phase with the least motion for image reconstruction (Best Phase, Siemens, Forchheim, Germany).…”