Comparison of chest computed tomography in Turbo FLASH mode with conventional mode for coronary artery disease screening: radiation dose, image quality, and calcium scoring performance.

Abstract

Background: Currently, the traditional chest computed tomography (CT) scan mode presents certain limitations in evaluating the coronary artery calcification score (CACS). Therefore, this study aimed to investigate the impact of using the Turbo FLASH mode to optimize chest CT on radiation dose, image quality, and CACS.

Methods: In this cross-sectional study, a total of 968 patients who simultaneously underwent routine chest CT (using the Turbo FLASH mode or the conventional mode) and cardiac CT [coronary calcium scan (CCS) and coronary CT angiography] were retrospectively collected. A comparative analysis was performed between the FLASH mode (n=493) and the conventional mode (n=475) in terms of radiation dose and image quality. CACS analysis was carried out using a semi-automatic software based on CCS, chest CT (FLASH), and chest CT (conventional). Using the CCS-CACS as a reference, the correlation, consistency, and concordance rate of risk categories based on CACS from the two chest CT modes were independently calculated.

Results: Chest CT (FLASH) reduced the mean radiation dose by 36.47 mGy·cm (11.1%) and exhibited fewer motion artifacts, albeit with a worse signal-to-noise ratio (SNR) (all P<0.05). For CACS quantification, chest CT (FLASH) showed a stronger linear correlation (r, 0.998 vs. 0.941) and higher consistency (mean difference, -5.653 vs. 7.142) compared to chest CT (conventional). For risk categories, chest CT (FLASH) set also demonstrated a higher concordance rate [91.3% (450/493) vs. 84% (399/475)]. Specifically, category 1 (CACS 1-10) exhibited the most significant improvement (78.5% vs. 53.5%). Additionally, chest CT (FLASH) had a lower false-negative rate [1% (5/493) vs. 4.6% (22/475)].

Conclusions: The Turbo FLASH mode of chest CT excels in detecting microcalcifications, reducing false negatives, and improving the accuracy of risk categories. It also lowers radiation exposure, but it may compromise the SNR of images.