Adaptive Iterative Dose Reduction 3D Integrated with Automatic Tube Current Modulation for CT Coronary Artery Calcium Quantification: Comparison to Traditional Filtered Back Projection in an Anthropomorphic Phantom and Patients

Ya-Chun Tang; Yuan-Chang Liu; Ming-Yi Hsu; Hui-Yu Tsai; Chien-Ming Chen

doi:10.1016/j.acra.2017.12.018

Adaptive Iterative Dose Reduction 3D Integrated with Automatic Tube Current Modulation for CT Coronary Artery Calcium Quantification: Comparison to Traditional Filtered Back Projection in an Anthropomorphic Phantom and Patients

Acad Radiol. 2018 Aug;25(8):1010-1017. doi: 10.1016/j.acra.2017.12.018. Epub 2018 Feb 1.

Authors

Ya-Chun Tang¹, Yuan-Chang Liu², Ming-Yi Hsu², Hui-Yu Tsai³, Chien-Ming Chen⁴

Affiliations

¹ Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital Linkou, 5 Fuxing Street, Kwei-Shan, Taoyuan, Taiwan 333.
² Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital Linkou, 5 Fuxing Street, Kwei-Shan, Taoyuan, Taiwan 333; College of Medicine, Chang Gung University, 259 Wen-Hwa 1st Road, Kwei-Shan, Taoyuan, Taiwan 333.
³ Medical Physics Research Center, Institute for Radiological Research, Chang Gung University/Chang Gung Memorial Hospital, Taoyuan, Taiwan; Department of Medical Imaging & Radiological Sciences, Chang Gung University, Taoyuan, Taiwan.
⁴ Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital Linkou, 5 Fuxing Street, Kwei-Shan, Taoyuan, Taiwan 333; College of Medicine, Chang Gung University, 259 Wen-Hwa 1st Road, Kwei-Shan, Taoyuan, Taiwan 333. Electronic address: dr.cmchen@gmail.com.

PMID: 29395796
DOI: 10.1016/j.acra.2017.12.018

Abstract

Rationale and objectives: We aimed to evaluate integrated adaptive iterative dose reduction 3D (AIDR 3D) algorithm in automatic tube current modulation (ATCM) for the quantification of coronary artery calcium score (CACS) and cardiac risk stratification.

Materials and methods: A thoracic phantom with calcium inserts of known densities was scanned with filtered back projection (FBP) and AIDR 3D algorithms in small- and medium-sized phantoms. Twenty-four patients underwent two consecutive scans of CACS with FBP and AIDR 3D algorithms. The absolute Agatston score, Agatston score risk, volume score, and Agatston score percentile-based risk were compared, and concordance coefficients and agreement plots were made.

Results: Agatston and volume scores were significantly different between the phantom sizes (P < .01). There were no significant differences in the Agatston scores between FBP and AIDR 3D for the medium phantoms (P = .25). In the patients, there were no significant differences in Agatston and volume scores between FBP and AIDR 3D (P = .06 and P = .09, respectively). The correlation coefficients of Agatston and volume scores with AIDR 3D were excellent compared to those of FBP. There were no significant differences in Agatston score risk and Agatston score percentile-based risk between FBP and AIDR 3D (P = .74 and P = 1, respectively). There was mean dose reduction of 57.8% ± 18.6% for AIDR 3D.

Conclusion: The absolute Agatston score differed between FBP and AIDR 3D reconstructions. However, the cardiac risk categorizations of the two methods were comparable. An integrated AIDR 3D algorithm with automatic tube current modulation enables radiation dose savings at a consistent noise level without sacrificing CACS.

Keywords: Agatston score; Cardiac CT; coronary calcium scan; iterative reconstruction; radiation dose.

Publication types

Comparative Study
Research Support, Non-U.S. Gov't

MeSH terms

Aged
Aged, 80 and over
Algorithms
Calcium
Coronary Artery Disease / diagnostic imaging*
Coronary Vessels / diagnostic imaging*
Female
Humans
Image Processing, Computer-Assisted / methods*
Male
Middle Aged
Phantoms, Imaging
Radiation Dosage
Tomography, X-Ray Computed / methods*
Vascular Calcification / diagnostic imaging*

Substances

Calcium