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Updated: Apr 28, 2026
Identifying Coronary Artery Calcification on Non-gated Computed Tomography Scans
Published on: August 28, 2018
The impact of CT radiation dose reduction and iterative reconstruction algorithms from four different vendors on
Martin J Willemink1, Richard A P Takx, Pim A de Jong
1Department of Radiology, Utrecht University Medical Center, P.O. Box 85500, E01.132, 3508 GA, Utrecht, The Netherlands, m.willemink@umcutrecht.nl.
Insights
Radiation dose reduction up to 80% did not affect coronary calcium scoring (CCS) using filtered back projection (FBP). Iterative reconstruction (IR) showed a trend towards lower scores, suggesting caution with IR for CCS.
Area of Science:
- Radiology
- Medical Imaging
- Cardiovascular Disease
Background:
- Coronary calcium scoring (CCS) is crucial for cardiovascular risk assessment.
- Optimizing radiation dose in computed tomography (CT) is essential.
- Iterative reconstruction (IR) algorithms offer potential for dose reduction.
Purpose of the Study:
- To evaluate the impact of radiation dose reduction on CCS.
- To assess the performance of iterative reconstruction (IR) algorithms in CCS.
- To compare different CT vendors and dose levels for CCS accuracy.
Main Methods:
- Fifteen ex vivo human hearts were scanned using CT across four vendors and four dose levels.
- Unenhanced, prospectively ECG-triggered protocols were employed.
- CT data were reconstructed using filtered back projection (FBP) and IR; Agatston scores, calcification mass, and volume were quantified.
Main Results:
- Dose reduction with FBP did not significantly alter CCS metrics (Agatston scores, volume, mass).
- IR demonstrated a trend towards lower Agatston scores and calcification volumes, with significant differences for one vendor.
- Median relative differences for IR reconstructions remained within clinically acceptable ranges.
Conclusions:
- Up to 80% radiation dose reduction is feasible for CCS using standard FBP.
- IR algorithms may lead to a trend of lower Agatston scores and calcification volumes.
- Caution is advised when using IR for CCS due to potential score variations.
Objectives:
To analyse the effects of radiation dose reduction and iterative reconstruction (IR) algorithms on coronary calcium scoring (CCS).
Methods:
Fifteen ex vivo human hearts were examined in an anthropomorphic chest phantom using computed tomography (CT) systems from four vendors and examined at four dose levels using unenhanced prospectively ECG-triggered protocols. Tube voltage was 120 kV and tube current differed between protocols. CT data were reconstructed with filtered back projection (FBP) and reduced dose CT data with IR. CCS was quantified with Agatston scores, calcification mass and calcification volume. Differences were analysed with the Friedman test.
Results:
Fourteen hearts showed coronary calcifications. Dose reduction with FBP did not significantly change Agatston scores, calcification volumes and calcification masses (P > 0.05). Maximum differences in Agatston scores were 76, 26, 51 and 161 units, in calcification volume 97, 27, 42 and 162 mm(3), and in calcification mass 23, 23, 20 and 48 mg, respectively. IR resulted in a trend towards lower Agatston scores and calcification volumes with significant differences for one vendor (P < 0.05). Median relative differences between reference FBP and reduced dose IR for Agatston scores remained within 2.0-4.6%, 1.0-5.3%, 1.2-7.7% and 2.6-4.5%, for calcification volumes within 2.4-3.9%, 1.0-5.6%, 1.1-6.4% and 3.7-4.7%, for calcification masses within 1.9-4.1%, 0.9-7.8%, 2.9-4.7% and 2.5-3.9%, respectively. IR resulted in increased, decreased or similar calcification masses.
Conclusions:
CCS derived from standard FBP acquisitions was not affected by radiation dose reductions up to 80%. IR resulted in a trend towards lower Agatston scores and calcification volumes.
Key Points:
In this ex vivo study, radiation dose could be reduced by 80% for coronary calcium scoring. Iterative reconstruction resulted in a trend towards lower Agatston scores and calcification volumes. Caution should be taken for coronary calcium scoring with iterative reconstruction.
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