Influence of iterative image reconstruction on CT-based calcium score measurements

Abstract

Iterative reconstruction techniques for coronary CT angiography have been introduced as an alternative for traditional filter back projection (FBP) to reduce image noise, allowing improved image quality and a potential for dose reduction. However, the impact of iterative reconstruction on the coronary artery calcium score is not fully known. In 112 consecutive stable patients with suspected coronary artery disease, the coronary calcium scores were assessed. Comparisons were made between the Agatston, volume and mass scores obtained with traditional FBP, and by using adaptive statistical iterative reconstruction (ASIR). A significant reduction of the Agatston score, volume score and mass score was observed for ASIR when compared to FBP, with median differences of resp. 26, 5 mm(3) and 1 mg. Using the ASIR reconstruction, the number of patients with a calcium score of zero increased by 13 %. Iterative CT reconstruction significantly reduces the Agatston, volume and mass scores. Since the calcium score is used as a prognostic tool for coronary artery disease, caution must be taken when using iterative reconstruction.

Influence of iterative reconstruction on coronary calcium scores at multiple heart rates: a multivendor phantom study on state-of-the-art CT systems

“…This finding is in agreement with recent studies, which show smaller variability for mass scores [26,38,41,42]. Many recent studies have shown that increasing levels of iterative reconstruction causes a reduction in CCS [12,16,40,[43][44][45][46][47][48]. This result was also established in our study.…”

“…The effect of iterative reconstruction on quantitative measurements in cardiovascular imaging has been subject of recent studies [11][12][13][14][15][16][17][18]. One of the most commonly used cardiovascular risk assessment tools in CT is coronary calcium scoring (CCS).…”

Coronary calcium screening with dual-source CT: reliability of ungated, high-pitch chest CT in comparison with dedicated calcium-scoring CT

“…However, the kilovoltage was kept constant for the chest and cardiac CT for each patient and the same threshold was applied for both quantitative approaches. Lastly, we used iterative reconstructions for all reconstructions, while there are contradictory results on their influence on the absolute values of CAC scores [22][23][24][25]. This technical aspect was beyond the scope of our study and it requires further investigation.…”

Impact of Hybrid Iterative Reconstruction on Agatston Coronary Artery Calcium Scores in Comparison to Filtered Back Projection in Native Cardiac CT

“…In contrast to the study by van Osch et al, our study had no patients with a score of 0 following HIR that had been > 0 in FBP. The number of patients with a score of 0 with ASIR increased by 13 % overall [13]. …”