Original Article


Superior CT coronary angiography image quality at lower radiation exposure with second generation 320-detector row CT in patients with elevated heart rate: a comparison with first generation 320-detector row CT

Dennis T. L. Wong, Siang Y. Soh, Brian S. H. Ko, James D. Cameron, Marcus Crossett, Arthur Nasis, John Troupis, Ian T. Meredith, Sujith K. Seneviratne

Abstract

Background: This study aims to compare the image quality of second generation versus first generation 320-computed tomography coronary angiography (CTCA) in patients with heart rate ≥65 bpm as it has not been specifically reported.
Methods: Consecutive patients who underwent CTCA using second-generation-320-detector-row-CT were prospectively enrolled. A total of 50 patients with elevated (≥65 bpm) heart rate and 50 patients with controlled (<65 bpm) heart rate were included. Age and gender matched patients who were scanned with the first-generation-320-detector-row-CT were retrospectively identified. Image quality in each coronary artery segment was assessed by two blinded CT angiographers using the five-point Likert scale.
Results: In the elevated heart rate cohorts, while there was no significant difference in heart rate during scan-acquisition (66 vs. 69 bpm, P=0.308), or body mass index (28.5 vs. 29.6, P=0.464), the second generation scanner was associated with better image quality (3.94±0.6 vs. 3.45±0.8, P=0.001), and with lower radiation (2.8 vs. 4.3 mSv, P=0.009). There was no difference in scan image quality for the controlled heart rate cohorts.
Conclusions: The second generation CT scanner provides better image quality at lower radiation dose in patients with elevated heart rate (≥65 bpm) compared to first generation CT scanner.

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