Transthoracic Doppler echocardiography to predict optimal tube pulsing window for coronary artery CT angiography
European Journal of Radiology, 08/17/2012
Sun G et al. – Doppler can help detecting the optimal pulsing windows accurately. Prospective ECG–gating incorporating Doppler analysis may narrow pulsing windows significantly while maintaining image quality.
- Doppler was performed on 135 patients before CT scanning.
- For Doppler, the intervals with minimal motion were evaluated during both systole and diastole integrating electrocardiogram (ECG) intervals.
- For CT scanning, the retrospective ECG-gating was applied and the optimal reconstruction intervals were determined.
- The accuracy of Doppler analysis to predict the optimal reconstruction intervals was tested.
- The predicted length of pulsing windows was compared between Doppler analysis and traditional prospective ECG-gating protocol (heart rate ≤ 65 bpm, 60–76%; 66–79 bpm, 30–77%; ≥80 bpm, 31–47%).
- According to Doppler analysis, the mean length of intervals with minimal motion in systole was 106.4 ± 39.2 ms and 125.2 ± 92.0 ms in diastole.
- When the intervals with minimal motion during diastole > 90 ms, the optimal reconstruction intervals were located at diastole; otherwise, at systole (P < 0.001).
- The optimal reconstruction intervals in 93.8% (132/135) patients could be predicted accurately by Doppler analysis.
- If the optimal reconstruction intervals predicted by Doppler were applied as the exposure windows, the mean length of pulsing windows should has been 105.2 ± 69.4 ms (range: 26.9–510.3 ms), which was significantly shorter than that of traditional prospective ECG-gating protocol (232.0 ± 120.2 ms, range: 93.2–427.3 ms, P < 0.001).