Coronary artery calcium (CAC) scanning is an important tool for risk stratification in intermediate-risk, asymptomatic subjects without previous coronary disease. However, the clinical benefit of improved risk prediction needs to be balanced against the risk of the use of ionizing radiation. Although there is increasing emphasis on the need to obtain CAC scans at low-radiation exposure to the patient, very few practical documents exist to aid laboratories and health care professionals on how to obtain such low-radiation scans.The Tomographic Imaging Council of the Society for Atherosclerosis Imaging and Prevention, in collaboration with the Prevention Council and the Society of Cardiovascular Computed Tomography, created a task force and writing group to generate a practical document to address parameters that can be influenced by careful attention to image acquisition.Patient selection for CAC scanning should be based on national guidelines. It is recommended that laboratories performing CAC examinations monitor radiation exposure (dose-length-product [DLP]) and effective radiation dose (E) in all patients. DLP should be <200 mGy × cm; E should average 1.0-1.5 mSv and should be <3.0 mSv. On most scanner platforms, CAC imaging should be performed in an axial mode with prospective electrocardiographic triggering, using tube voltage of 120 kVp. Tube current should be carefully selected on the basis of patient size, potentially using chest lateral width measured on the topogram. Scan length should be limited for the coverage of the heart only.When patients and imaging parameters are selected appropriately, CAC scanning can be performed with low levels of radiation exposure.
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Conflict of interest : D.S.B. has received grant support from Lantheus, GE/Amersham, Siemens, and Astellas Healthcare ; is a consultant for Astellas Healthcare, Flouro Pharma, and Magellam; has received royalty income from CSMC Software Royalties; and is a shareholder of Spectrum Dynamics stock. M.J.B. is on the speaker's bureau of GE. R.C.C. has received grant support for research from Astellas Pharma, Pfizer, IMC, and GE Healthcare and is consultant for Astellas Pharma. S.S.H. has received grant support for research from Siemens Healthcare and is a consultant for Philips Healthcare. H.S.H. is on the speaker's bureau for Philips Medical System. R.D.S. is on the speaker’s bureau for Pfizer, AstraZeneca, Merck, Novartis, GSK, and BMS and is a consultant for Genzyme and Novo Nordisk. S.V. has received grant support for research from Toshiba America Medical Systems and Vital Images . R.B. M.Y.D., D.D., K.N., J.J.R., M.D.S., A.J.T., U.S.V., G.W., and P.M.Y. report no conflicts of interest.
Copyright 2011 Elsevier B.V., All rights reserved.
- Coronary artery calcium
- Multidetector CT
- Radiation dose
- Radiation exposure