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Dose indices: everybody wants a number

  • Image Gently ALARA CT summit: How to Use New CT Technologies for Children
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Abstract

This paper discusses the merits and weaknesses of the standard terms that have been developed to quantify CT dose: CT dose indices (CTDI), dose length product (DLP) and effective dose. The difference between the measured CTDIvol and the CTDIvol displayed on the CT scanner illustrates a clinical dilemma. Displayed CTDIvol represents the radiation dose delivered to a plastic phantom, which is significantly different from the dose delivered to the patient, depending on the size of the patient. Although effective dose is simple to calculate for an individual patient, it was never intended for this purpose. The need for a simple, appropriate method to estimate pediatric patient doses led to the development of the size-specific dose estimate (SSDE), the newest CT dose index. Here I compare SSDE and its merits to the use of effective dose to estimate patient dose. The discussion concludes with a few sample calculations and basic clinical applications of SSDE to better quantify pediatric patient dose from CT scans.

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Conflicts of interest

Keith Strauss provides paid consulting services to Philips Healthcare (Best, The Netherlands) upon request.

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  1. Department of Radiology, Cincinnati Children’s Hospital Medical Center, MLC 50311, 3333 Burnet Ave., Cincinnati, OH, 45229-3026, USA

    Keith J. Strauss

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  1. Keith J. Strauss
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Correspondence to Keith J. Strauss.

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Strauss, K.J. Dose indices: everybody wants a number. Pediatr Radiol 44 (Suppl 3), 450–459 (2014). https://doi.org/10.1007/s00247-014-3104-z

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  • DOI: https://doi.org/10.1007/s00247-014-3104-z

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