High-pitch versus sequential mode for coronary calcium in individuals with a high heart rate: Potential for dose reduction.
J Cardiovasc Comput Tomogr. 2018 Jul - Aug;12(4):298-304. doi: 10.1016/j.jcct.2018.02.005. Epub 2018 Mar 1. Vonder M1, Vliegenthart R2, Kaatee MA3, van der Aalst CM4, van Ooijen PMA5, de Bock GH6, Gratama JW7, Kuijpers D8, de Koning HJ9, Oudkerk M10.
BACKGROUND: To determine the impact of high-pitch spiral acquisition on radiation dose and cardiovascular disease (CVD) risk stratification by coronary artery calcium (CAC) assessment with computed tomography in individuals with a high heart rate.
METHODS: Of the ROBINSCA trial, 1990 participants with regular rhythm and heart rates >65 beats per minute (bpm) were included. As reference, 390 participants with regular heart rates ≤65 bpm were used. All participants underwent prospectively electrocardiographically(ECG)-triggered imaging of the coronary arteries using dual source CT at 120 kVp, 80 ref mAs using both high-pitch spiral mode and sequential mode. Radiation dose, Agatston score, number of positive scores, as well as median absolute difference of the Agatston score were determined and participants were stratified into CVD risk categories.
RESULTS: A similar percentage of participants with low heart rates and high heart rates had a positive CAC score in data sets acquired in high-pitch spiral (low heart rate: 57.7%, high heart rate: 55.8%) and sequential mode (58.0%, 54.7%, p = n.s.). The median absolute difference in Agatston scores between acquisition modes was 14.2% and 9.2%, for the high and low heart rate groups, respectively. Excellent agreement for risk categorization between the two data acquisition modes was found for the high (κ = 0.927) and low (κ = 0.946) heart rate groups. Radiation dose was 48% lower for high-pitch spiral versus sequential acquisitions.
CONCLUSION: Radiation dose for the quantification of coronary calcium can be reduced by 48% when using the high-pitch spiral acquisition mode compared to the sequential mode in participants with a regular high heart rate. CVD risk stratification agreement between the two modes of data acquisition is excellent.