Aims and objectives
Thepatients with atrial fibrillation were a major challenge for coronary CT angiography examinations,
and HR variation may lead to the inappropriate data sampling and severe motion artefacts.
But the new CT scanners can eliminate ‘‘stair-step’’ artefacts.
Jus like the 320-detector row CT or the 2-generation dual source computed tomography,
which could obtain whole heart imaging in one heart cycle.
However,
patients with atrial fibrillation and high heart rates would experience higher radiation exposure.
The purpose of this study is to investigate whether it is possible...
Methods and materials
Thirty-five patients with atrial fibrillation and heart rates (HR) above 65 bpm were enrolled in this study.
Low dose coronary calcium scanning (CACS) (100KV,
300mA) was performed before CT coronary angiography (CCTA).
The traditional prospective CCTA(80~120KV,
300~550mA,
base on the habitus) was performed.
The raw data of all beats were reconstructed using multi-segment algorithm (Fig A).
The raw data of first beat were reconstructed using the half-segment algorithm (Fig B). Two radiologists assessed the image quality of middle right coronary artery for coronary calcium scanning....
Results
According to CACS analysis,
the quality scores was 1.4+/-0.65.
When HR above 65 bpm or HR variability changes 20% during CCTA,
the optimal scan plus window was located at diastole.
The optimal exposure windows and one heartbeat scan acquisition mode in 82.8% (29/35) patients could be predicted accurately by CACS analysis.
The quality scores of half-segment images and multi-segment images on the CCTA correlated with that of the CACS (r = 0.81,
and r = 0.76).
If the optimal exposure windows and one heartbeat scan...
Conclusion
The CACS analysis can predict the quality scores of CCTA in patients with atrial fibrillation.
Prospective ECG-gating incorporating CACS analysis may improve scan protocol for reduction of radiation dose significantly while maintaining image quality.
References
1.
Achenbach S,
Marwan M,
Schepis T et al (2009) High-pitch spiral acquisition: a new scan mode for coronary CT angiography.
J Cardiovasc Comput Tomogr 3(2):117–121
2.
Austen W,
Edwards J,
Frye R et al (1975) A reporting system on patients evaluated for coronary artery disease.
Report of the Ad Hoc Committee for Grading of Coronary Artery Disease,
Council on Cardiovascular Surgery,
American Heart Association.
Circulation 51(4):5–40
3.
Cademartiri F,
Mollet NR,
Runza G et al (2006) Improving diagnostic accuracy of MDCT coronary angiography in...