Estimating effective dose for ct using dose-length product compared with using organ doses: Consequences of adopting international commission on radiological protection publication 103 or dual-energy scanning

Jodie A. Christner, James M. Kofler, Cynthia H. McCollough

Research output: Contribution to journalArticle

277 Scopus citations

Abstract

OBJECTIVE. The objective of our study was to compare dose-length product (DLP)- based estimates of effective dose with organ dose-based calculations using tissue-weighting factors from publication 103 of the International Commission on Radiological Protection (ICRP) or dual-energy CT protocols. MATERIALS AND METHODS. Using scanner- and energy-dependent organ dose coefficients, we calculated effective doses for CT examinations of the head, chest, coronary arteries, liver, and abdomen and pelvis using routine clinical single- or dual-energy protocols and tissue-weighting factors published in 1991 in ICRP publication 60 and in 2007 in ICRP publication 103. Effective doses were also generated from the respective DLPs using published conversion coefficients that depend only on body region. For each examination type, the same volume CT dose index was used for single- and dual-energy scans. RESULTS. Effective doses calculated for CT examinations using organ dose estimates and ICRP 103 tissue-weighting factors differed relative to ICRP 60 values by -39% (-0.5 mSv, head), 14% (1 mSv, chest), 36% (4 mSv, coronary artery), 4% (0.6 mSv, liver), and -7% (-1 mSv, abdomen and pelvis). DLP-based estimates of effective dose, which were derived using ICRP 60-based conversion coefficients, were less than organ dose-based estimates for ICRP 60 by 4% (head), 23% (chest), 37% (coronary artery), 12% (liver), and 19% (abdomen and pelvis) and for ICRP 103 by -34% (head), 37% (chest), 74% (coronary artery), 16% (liver), and 12% (abdomen and pelvis). All results were energy independent. CONCLUSION. These differences in estimates of effective dose suggest the need to reassess DLP to E conversion coefficients when adopting ICRP 103, particularly for scans over the breast. For the evaluated scanner, DLP to E conversion coefficients were energy independent, but ICRP 60-based conversion coefficients underestimated effective dose relative to organ dose-based calculations.

Original languageEnglish (US)
Pages (from-to)881-889
Number of pages9
JournalAmerican Journal of Roentgenology
Volume194
Issue number4
DOIs
StatePublished - Apr 1 2010

    Fingerprint

Keywords

  • CT
  • DLP
  • Dose-length product
  • Dual-energy CT
  • Effective dose
  • Effective dose equivalent
  • ICRP publication 103
  • ICRP publication 26
  • ICRP publication 60
  • Organ dose
  • Tissue-weighting factors

ASJC Scopus subject areas

  • Radiology Nuclear Medicine and imaging

Cite this