Coronary Artery Calcium: A Multi-institutional, Multimanufacturer International Standard for Quantification at Cardiac CT

McCollough, Cynthia H.; Ulzheimer, Stefan; Halliburton, Sandra S.; Shanneik, Kaiss; White, Richard D.; Kalender, Willi A.

doi:10.1148/radiol.2432050808

Cited by 267 publications

(293 citation statements)

References 20 publications

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“…This might not reflect the optimal tube current with regard to accuracy and radiation dose, which let appear our dose calculations being relatively arbitrary. A recent phantom study on CS has shown that size-specific tube current values yielded comparable data among different patient sizes and thus recommended the implementation of adjusted tube current time product settings for small, medium and large patients [9]. This is in line with the results from the study of Muhlenbruch et al [10] who adjustedsimilar to our protocol E-the tube current to the patients body constitution by means of attenuationbased tube current modulation.…”

Section: Study Limitationssupporting

confidence: 84%

“…In order to keep radiation exposure as low as reasonably achievable (ALARA), recent modifications of multi-slice CT scanning protocols have been implemented, such as the use of a low tube current [8,9], attenuation-based tube current modulation [10], and use of low tube voltage protocols [11,12]. In general, two modes of phase synchronization have been traditionally used, i.e., the retrospective electrocardiography (ECG)-gating technique [13,14] that acquires continuous data in a helical (spiral) mode and the prospective ECGtriggering technique [15,16] that obtains data at predefined time points of the cardiac cycle in an axial step-and-shoot mode, the latter usually being associated with a lower radiation dose.…”

Section: Introductionmentioning

confidence: 99%

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Radiation dose values for various coronary calcium scoring protocols in dual-source CT

Stolzmann

Leschka

Betschart

et al. 2008

Int J Cardiovasc Imaging

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Purpose The purpose of this study was to assess the radiation dose and associated image noise of previously suggested calcium scoring protocols using dual-source CT. Methods One hundred consecutive patients underwent coronary calcium scoring using dual-source CT. Patients were randomly assigned to five different protocols: retrospective ECG-gating and tube current reduction to 4% outside the pulsing window at 120 (protocol A) and 100 kV (B), prospective ECG-triggering at 120 (C) and 100 kV (D), and prospective ECG-triggering at 100 kV with attenuation-based tube current modulation (E). Radiation dose parameters and image noise were determined and compared. Results Protocol A resulted in an effective dose of 1.3 ± 0.2 mSv, protocol B in 0.8 ± 0.2 mSv, protocol C in 1.0 ± 0.2 mSv, protocol D in 0.6 ± 0.1 mSv, and protocol E in 0.7 ± 0.1 mSv. Effective doses were significantly lower (P \ 0.001) with 100 kV when compared to 120 kV protocols, and were significantly lower (P \ 0.001) for prospective versus retrospective ECG-gating. No significant difference was found between protocol D and E. Significant negative correlations were found between the CTDI vol and heart rate for both retrospective ECGgating protocols (protocol A: r = -0.98, P \ 0.001; protocol B: r = -0.83, P \ 0.001). The mean image noise was 29.0 ± 6.7 HU, with no significant differences between the five protocols. The image noise was significantly correlated with the body weight (r = 0.21, P \ 0.05) and BMI (r = 0.31, P \ 0.01). Conclusions Effective dose of calcium scoring using dual-source CT ranges from 0.6 to 1.3 mSv. Prospective triggering and lower tube voltage significantly reduces the radiation but yield similar image noise.

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Section: Study Limitationssupporting

confidence: 84%

Section: Introductionmentioning

confidence: 99%

Radiation dose values for various coronary calcium scoring protocols in dual-source CT

Stolzmann

Leschka

Betschart

et al. 2008

Int J Cardiovasc Imaging

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“…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]. The use of different iteration algorithms is also a possible cause [27].…”

Section: Radiation Dosementioning

confidence: 99%

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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“…Although the standardization of CTHU was done by individual manufacturers, and the calibration procedure was performed before the row data reconstruction, a significant variation between scanners still exists [36,43]. The stabilization of CTHU can be influenced by numerous factors, including the scanner's model, scan algorithm parameters [44], patient's body size [35] and many other factors, which needs to be corrected before any quantitative assessment. Moreover, the attenuation Fig.…”

Section: Phantomless Assessment Of the Thoracic Vertebral Bmd Using Amentioning

confidence: 99%

Application of quantitative computed tomography for assessment of trabecular bone mineral density, microarchitecture and mechanical property

et al. 2016

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a b s t r a c t a r t i c l e i n f oOsteoporosis is a common metabolic bone disease, causing increased skeletal fragility characterized by a low bone mass and trabecular microarchitectural deterioration. Assessment of the bone mineral density (BMD) is the primary determinant of skeletal fragility. Computed tomography (CT)-based trabecular microarchitectural and mechanical assessments are important methods to evaluate the skeletal strength. In this review, we focus the feasibility of QCT BMD measurement using a calibration phantom or phantomless. The application of QCT could extend the bone mineral density assessment to all patients who underwent a heart, lung, whole-body, and as well as all routine clinical implications of CT scan.

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Coronary Artery Calcium: A Multi-institutional, Multimanufacturer International Standard for Quantification at Cardiac CT

Abstract: Standardized quantification of CAC yielded comparable image noise, spatial resolution, and mass scores among different patient sizes and different CT systems and facilitated reduced radiation dose for small and medium-size patients.

Cited by 267 publications

References 20 publications

Radiation dose values for various coronary calcium scoring protocols in dual-source CT

Radiation dose values for various coronary calcium scoring protocols in dual-source CT

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

Application of quantitative computed tomography for assessment of trabecular bone mineral density, microarchitecture and mechanical property

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