Coronary artery calcium scoring: Influence of adaptive statistical iterative reconstruction using 64-MDCT

Gebhard, Cathérine; Fiechter, Michael; Fuchs, Tobias A.; Ghadri, Jelena R.; Herzog, Bernhard A.; Kuhn, Félix P.; Stehli, Julia; Müller, E.; Kazakauskaitė, Eglė; Gaemperli, Oliver; Kaufmann, Philipp A.

doi:10.1016/j.ijcard.2012.08.003

Cited by 68 publications

(61 citation statements)

References 38 publications

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“…In a phantom study, Murazaki et al demonstrated that there are no significant differences in Agatston score derived from FBP (50 mAs) and iDose (15 mAs) when the same tube voltage is used [15]. Using CT-systems of other manufacturers and their iteration algorithms led in some cases to different results compared to our study (see also [12]). For one, a scanner-toscanner variability of Agatston score is described [26].…”

Section: Radiation Dosecontrasting

confidence: 60%

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

Obmann

Klink

Heverhagen

et al. 2015

Fortschr Röntgenstr

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Purpose: To investigate whether the effects of hybrid iterative reconstruction (HIR) on coronary artery calcium (CAC) measurements using the Agatston score lead to changes in assignment of patients to cardiovascular risk groups compared to filtered back projection (FBP). Materials and Methods: 68 patients (mean age 61.5 years; 48 male; 20 female) underwent prospectively ECG-gated, non-enhanced, cardiac 256-MSCT for coronary calcium scoring. Scanning parameters were as follows: Tube voltage, 120 kV; Mean tube current time-product 63.67?mAs (50???150?mAs); collimation, 2???128???0.625?mm. Images were reconstructed with FBP and with HIR at all levels (L1 to L7). Two independent readers measured Agatston scores of all reconstructions and assigned patients to cardiovascular risk groups. Scores of HIR and FBP reconstructions were correlated (Spearman). Interobserver agreement and variability was assessed with ?-statistics and Bland-Altmann-Plots. Results: Agatston scores of HIR reconstructions were closely correlated with FBP reconstructions (L1, R?=?0.9996; L2, R?=?0.9995; L3, R?=?0.9991; L4, R?=?0.986; L5, R?=?0.9986; L6, R?=?0.9987; and L7, R?=?0.9986). In comparison to FBP, HIR led to reduced Agatston scores between 97?% (L1) and 87.4?% (L7) of the FBP values. Using HIR iterations L1???L3, all patients were assigned to identical risk groups as after FPB reconstruction. In 5.4?% of patients the risk group after HIR with the maximum iteration level was different from the group after FBP reconstruction. Conclusion: There was an excellent correlation of Agatston scores after HIR and FBP with identical risk group assignment at levels 1 - 3 for all patients. Hence it appears that the application of HIR in routine calcium scoring does not entail any disadvantages. Thus, future studies are needed to demonstrate whether HIR is a reliable method for reducing radiation dose in coronary calcium scoring. Key Points: ??Agatston-Scores showed excellent correlation between HIR and FBP. ??The higher the HIR Level, the more Agatston scores deviated to lower values. ??No change in risk group assignment using Level 1???3. ??Change in risk group assignment when using HIR compared to FBP in 1.5?% (Level?4), 5.4?% (Level 5???7). Citation Format: ??Obmann VC, Klink T, Heverhagen JT et?al. Impact of Hybrid Iterative Reconstruction on Agatston Coronary Artery Calcium Scores in Comparison to Filtered Back Projection in Native Cardiac CT. Fortschr R?ntgenstr 2015; 187: 372???379

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Section: Radiation Dosecontrasting

confidence: 60%

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

Obmann

Klink

Heverhagen

et al. 2015

Fortschr Röntgenstr

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“…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).…”

Section: Introductionmentioning

confidence: 99%

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

Werf

Willemink

Willems

et al. 2017

Int J Cardiovasc Imaging

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The objective of this study was to evaluate the influence of iterative reconstruction on coronary calcium scores (CCS) at different heart rates for four state-of-the-art CT systems. Within an anthropomorphic chest phantom, artificial coronary arteries were translated in a water-filled compartment. The arteries contained three different calcifications with low (38 mg), medium (80 mg) and high (157 mg) mass. Linear velocities were applied, corresponding to heart rates of 0, < 60, 60-75 and > 75 bpm. Data were acquired on four state-of-the-art CT systems (CT1-CT4) with routinely used CCS protocols. Filtered back projection (FBP) and three increasing levels of iterative reconstruction (L1-L3) were used for reconstruction. CCS were quantified as Agatston score and mass score. An iterative reconstruction susceptibility (IRS) index was used to assess susceptibility of Agatston score (IRS AS ) and mass score (IRS MS ) to iterative reconstruction. IRS values were compared between CT systems and between calcification masses. For each heart rate, differences in CCS of iterative reconstructed images were evaluated with CCS of FBP images as reference, and indicated as small (< 5%), medium (5-10%) or large (> 10%). Statistical analysis was performed with repeated measures ANOVA tests. While subtle differences were found for Agatston scores of low mass calcification, medium and high mass calcifications showed increased CCS up to 77% with increasing heart rates. IRS AS of CT1-T4 were 17, 41, 130 and 22% higher than IRS MS . Not only were IRS significantly different between all CT systems, but also between calcification masses. Up to a fourfold increase in IRS was found for the low mass calcification in comparison with the high mass calcification. With increasing iterative reconstruction strength, maximum decreases of 21 and 13% for Agatston and mass score were found. In total, 21 large differences between Agatston scores from FBP and iterative reconstruction were found, while only five large differences were found between FBP and iterative reconstruction mass scores. Iterative reconstruction results in reduced CCS. The effect of iterative reconstruction on CCS is more prominent with low-density calcifications, high heart rates and increasing iterative reconstruction strength.

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“…Clinically, accurate and reliable assessment of plaque compositions would be crucial as low attenuation plaques and positive vessel remodelling have been identified as key features of lesions with high risk for rupture causing an acute coronary syndrome [9]. Currently, a new generation of high definition CT scanners (Discovery HD 750, GE Healthcare), are being introduced with substantially improved spatial resolution (0.23 9 0.23 mm in-plane resolution) complemented by a new adaptive statistical iterative reconstruction (ASIR, GE Healthcare) algorithm to compensate for the increased noise due to the higher resolution [10,11]. This may contribute to overcome issues of limited contrast resolution and blooming artefacts from coronary calcifications or stents as ASIR was developed to help reducing noise associated with standard convolution reconstruction algorithms [12,13].…”

Section: Introductionmentioning

confidence: 99%

CT coronary angiography: impact of adapted statistical iterative reconstruction (ASIR) on coronary stenosis and plaque composition analysis

Fuchs

Fiechter

Gebhard

et al. 2012

Int J Cardiovasc Imaging

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To assess the impact of adaptive statistical iterative reconstruction (ASIR) on coronary plaque volume and composition analysis as well as on stenosis quantification in high definition coronary computed tomography angiography (CCTA). We included 50 plaques in 29 consecutive patients who were referred for the assessment of known or suspected coronary artery disease (CAD) with contrast-enhanced CCTA on a 64-slice high definition CT scanner (Discovery HD 750, GE Healthcare). CCTA scans were reconstructed with standard filtered back projection (FBP) with no ASIR (0 %) or with increasing contributions of ASIR, i.e. 20, 40, 60, 80 and 100 % (no FBP). Plaque analysis (volume, components and stenosis degree) was performed using a previously validated automated software. Mean values for minimal diameter and minimal area as well as degree of stenosis did not change significantly using different ASIR reconstructions. There was virtually no impact of reconstruction algorithms on mean plaque volume or plaque composition (e.g. soft, intermediate and calcified component). However, with increasing ASIR contribution, the percentage of plaque volume component between 401 and 500 HU decreased significantly (p \ 0.05). Modern image reconstruction algorithms such as ASIR, which has been developed for noise reduction in latest high resolution CCTA scans, can be used reliably without interfering with the plaque analysis and stenosis severity assessment.

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Coronary artery calcium scoring: Influence of adaptive statistical iterative reconstruction using 64-MDCT

Cited by 68 publications

References 38 publications

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

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

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

CT coronary angiography: impact of adapted statistical iterative reconstruction (ASIR) on coronary stenosis and plaque composition analysis

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