Browse > Article
http://dx.doi.org/10.14316/pmp.2015.26.1.28

Effects of Iterative Reconstruction Algorithm, Automatic Exposure Control on Image Quality, and Radiation Dose: Phantom Experiments with Coronary CT Angiography Protocols  

Ha, Seongmin (Yonsei - Cedars-Sinai, Integrative Cardiovascular Imaging Research Center)
Jung, Sunghee (Graduate School of Medical Sciences, College of Medicine, Yonsei University)
Chang, Hyuk-Jae (Graduate School of Medical Sciences, College of Medicine, Yonsei University)
Park, Eun-Ah (Department of Radiology, Seoul National University Hospital)
Shim, Hackjoon (Toshiba Medical Systems Korea)
Publication Information
Progress in Medical Physics / v.26, no.1, 2015 , pp. 28-35 More about this Journal
Abstract
In this study, we investigated the effects of an iterative reconstruction algorithm and an automatic exposure control (AEC) technique on image quality and radiation dose through phantom experiments with coronary computed tomography (CT) angiography protocols. We scanned the AAPM CT performance phantom using 320 multi-detector-row CT. At the tube voltages of 80, 100, and 120 kVp, the scanning was repeated with two settings of the AEC technique, i.e., with the target standard deviations (SD) values of 33 (the higher tube current) and 44 (the lower tube current). The scanned projection data were reconstructed also in two ways, with the filtered back projection (FBP) and with the iterative reconstruction technique (AIDR-3D). The image quality was evaluated quantitatively with the noise standard deviation, modulation transfer function, and the contrast to noise ratio (CNR). More specifically, we analyzed the influences of selection of a tube voltage and a reconstruction algorithm on tube current modulation and consequently on radiation dose. Reduction of image noise by the iterative reconstruction algorithm compared with the FBP was revealed eminently, especially with the lower tube current protocols, i.e., it was decreased by 46% and 38%, when the AEC was established with the lower dose (the target SD=44) and the higher dose (the target SD=33), respectively. As a side effect of iterative reconstruction, the spatial resolution was decreased by a degree that could not mar the remarkable gains in terms of noise reduction. Consequently, if coronary CT angiogprahy is scanned and reconstructed using both the automatic exposure control and iterative reconstruction techniques, it is anticipated that, in comparison with a conventional acquisition method, image noise can be reduced significantly with slight decrease in spatial resolution, implying clinical advantages of radiation dose reduction, still being faithful to the ALARA principle.
Keywords
Iterative reconstruction; AEC; Low-dose CT; CCTA; Phantom experiment;
Citations & Related Records
연도 인용수 순위
  • Reference
1 MEDPAC: A Data Book: Healthcare Spending and the Medicare Program. Medicare Payment Advisory Commission, (2013)
2 Smith-Bindman R, Lipson J, Marcus R, et al: Radiation dose associated with common computed tomography examinations and the associated lifetime attributable risk of cancer, Arch Intern Med 169(22):2079-2086 (2009)
3 ICRP Publication 102: Managing patient dose in multi-detector computed tomography(MDCT).Ann ICRP 37(1):1-79 (2006)   DOI
4 Hsieh J: Computed tomography: principles, design, artifacts, and recent advances, SPIE, (2009)
5 Dougeni E, Faulkner K, Panayiotakis G: A review of patient dose and optimisation methods in adult and paediatric CT scanning, Eur J Radiol 81(4):665-683 (2011)
6 Payne JT: CT radiation dose and image quality, Radiol Clin North Am 43(6):953-962 (2005)   DOI
7 Hara AK, Paden RG, Silva AC, et al: Iterative reconstruction technique for reducing body radiation dose at CT: feasibility study, AJR Am J Roentgenology 193(3):764-771 (2009)   DOI
8 Xu J, Mahesh M, Tsui BM: Is iterative reconstruction ready for MDCT?, J Am Coll Radiol. 6(4):274-276 (2009)   DOI
9 Denis T, Kalra MK, Gevenois PA: Radiation dose from multidetector CT. 2nd ed, Springer (2012), pp 152-154
10 Von Spiczak J1, Morsbach F, Winklhofer S, et al: Coronary artery stent imaging with CT using an integrated electronics detector and iterative reconstructions: first in vitro experience, J Cardiovasc Comput Tomogr 7(4):215-222 (2013)   DOI
11 Ohashi K, Ichikawa K, Hara M: Examination of the optimal temporal resolution required for computed tomography coronary angiography, Radiol Phys Technol 6(2):453-460 (2013)   DOI
12 Gervaise A, Osemont B, Lecocq S: CT image quality improvement using adaptive iterative dose reduction with widevolume acquisition on 320-detector CT, European radiology 22(2):295-301 (2012)   DOI
13 Nakaya Y, Kawata Y, Niki N, et al: A method for determining the modulation transfer function from thick microwire profiles measured with x-ray microcomputed tomography, Medical Physics 39(7):4347-4364 (2012)   DOI
14 Ohkubo M, Wada S, Matsumoto T, et al: An effective method to verify line and point spread functions measured in computed tomography, Medical physics 33(8):2757-2764 (2006)   DOI
15 L. del Risco Norrlid, C. Ronnqvist, K. Fransson, et al: Calculation of the modulation transfer function for the X-ray imaging detector DIXI using Monte Carlo simulation data, Nuclear Instruments and Methods in Physics Research Section A 466(1):209-217, (2001)   DOI
16 Samei E, Ranger NT, Dobbins JT 3rd, et al: Intercomparison of methods for image quality characterization. I. Modulation transfer function, Medical physics 33(5):1454-1465 (2006)   DOI
17 Kenneth AF, Nicholas JH, Beth AS, et al: Measurement of the presampled two-dimensional modulation transfer function of digital imaging systems, Medical physics 29(5) 913-921 (2002)   DOI
18 Halliburton SS, Abbara S, Chen MY, et al: SCCT guidelines on radiation dose and dose-optimization strategies in cardiovascular CT, Journal of Cardiovascular Computed Tomography 5(4):198-224 (2011)   DOI
19 Kalra MK, Maher MM, Toth TL, et al: Strategies for CT radiation dose optimization. Radiology 230(3):619-628 (2004)   DOI
20 ICRP publication 103: The 2007 Recommendations of the International Commission on Radiological Protection, Ann ICRP 37(2-4):(2007)
21 Sharma RK, Voelker DJ, Sharma RK: Coronary computed tomographic angiography (CCTA) in community hospitals: "current and emerging role", Vasc Health Risk Manag 25(6): 307-316 (2010)