Quantification of radiation dose savings in cardiac computed tomography using prospectively triggered mode and ECG pulsing: a phantom study
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To quantify radiation dose reduction in cardiac computed tomography (CT) using a prospectively triggered mode compared with a retrospective ECG-gated helical mode.
Absorbed organ doses in cardiac 64-row multidetector CT were quantified using an anthropomorphic male Alderson phantom with 74 thermoluminescence dosimeters. Three different imaging protocols were applied: retrospective ECG-gating, retrospective ECG-gating with additional ECG-pulsing, and a prospectively triggered mode. The measured organ doses were compared with dose estimation by a mathematical phantom.
Compared with the retrospective ECG-gating mode, the mean relative organ doses were reduced by 44% using ECG pulsing and by 76% using the prospectively triggered mode. The range of dose savings varied from 34% to 49% using ECG pulsing and from 65% to 87% using the prospectively triggered mode. The effective dose was 16.5 mSv using retrospective gating, 9.2 mSv using retrospective gating with ECG pulsing and 4.0 mSv using the prospectively triggered mode.
Our measurements confirm the high dose-saving potential of the prospectively triggered technique in cardiac CT. The reduction in the organ doses measured corresponds to estimates determined by the mathematical phantom. The effective dose calculated by the mathematical phantom was, in some cases, significantly lower than that calculated using the anthropomorphic phantom.
KeywordsComputed tomography Prospective gating Radiation dose Organ dose Phantom
- 2.Budoff MJ, Dowe D, Jollis JG, Gitter M, Sutherland J, Halamert E et al (2008) Diagnostic performance of 64-multidetector row coronary computed tomographic angiography for evaluation of coronary artery stenosis in individuals without known coronary artery disease: results from the prospective multicenter ACCURACY (Assessment by Coronary Computed Tomographic Angiography of Individuals Undergoing Invasive Coronary Angiography) trial. J Am Coll Cardiol 52:1724–1732CrossRefPubMedGoogle Scholar
- 13.Shrimpton PC (2004) Assessment of patient dose in CT. NRPB-PE/1/2004Google Scholar
- 17.Kramer R, Zankl M, Williams G, Drexler G (1982) The calculation of dose from external photon exposures using reference human phantoms and Monte Carlo methods. Part I. The male (Adam) and female (Eva) adult mathematical phantoms. GSF-Report S-885. NeuherbergGoogle Scholar
- 18.International Commission on Radiological Protection (ICRP) 60 (1991) Recommendations of the International Commission on Radiological Protection. Pergamon Press, OxfordGoogle Scholar
- 20.Zankl M, Panzer W, Drexler G (1991) The calculation of dose from external photon exposures using reference human phantoms and Monte Carlo methods. Part VI. Organ doses from computed tomographic examinations. GSF-Report 30/91. Institute for Radiation Biology, NeuherbergGoogle Scholar
- 21.Shleien B (1973) Review of determinations of radiation dose to the active bone marrow from diagnostic X-ray examinations. DHEW publication—no. (FDA) 74–8007, RockvilleGoogle Scholar
- 22.DeMarco JJ, Cagnon CH, Cody DD, Stevens DM, McCollough CH, Zankl M et al (2007) Estimating radiation doses from multidetector CT using Monte Carlo simulations: effects of different size voxelized patient models on magnitudes of organ and effective dose. Phys Med Biol 52:2583–2597CrossRefPubMedGoogle Scholar
- 24.Veit R, Panzer W, Zankl M, Scheurer C (1992) Vergleich berechneter und gemessener Dosen an einem anthropomorphen Phantom. Z Med Phys 2:123–126Google Scholar
- 33.Shuman WP, Branch KR, May JM, Mitsumori LM, Strote JN, Warren BH et al (2009) Whole-chest 64-MDCT of emergency department patients with nonspecific chest pain: radiation dose and coronary artery image quality with prospective ECG triggering versus retrospective ECG gating. AJR Am J Roentgenol 192:1662–1667CrossRefPubMedGoogle Scholar
- 35.The 2007 Recommendations of the International Commission on Radiological Protection (2007) ICRP publication 103, Ann ICRP 37:1–332Google Scholar
- 36.Hart D, Jones DG, Wang M (1994) Normalised organ doses for medical X-ray examinations calculated using Monte-Carlo techniques (NRPB-SR262). National Radiological Protection Board, ChiltonGoogle Scholar