Conversion coefficients for dose estimation from dose-length product (DLP) in CT examination
Radiation dose from a CT examination in standard body regions can be estimated from the dose-lenght product (DLP) that each CT outputs. This table shows known commonly used coefficients and their adjustment in two particular CT machines. The calculation of the efective dose estimation is:
E(mSv) = coefficient * DLP * 0.001
The most recent recommendation is based on the ICRP 103 publication (last column).
| Scanned body region | Conversion coefficient [10-3mSv.mGy-1.cm-1] | |||
|---|---|---|---|---|
| General | Somatom Sensation 16 | iCT 256 | ICRP-103 | |
| Head | 2.1 | 2.2 | 2.1 | 1.9 |
| Head and neck | 3.1 | |||
| Neck | 5.9 | 5.4 | 5.1 | |
| Thorax | 14 | 17 | 14 | 14.5 |
| Abdomen | 15 | 16 | 12 | 15.3 |
| Pelvis | 15 | 18 | 16 | 12.9 |
| Trunk | 15 | 17 | 15.2 | |
References:
1. McCollough C, Cody D, Edyvean S, et al. AAPM report no. 96: the measurement, reporting, and management of radiation dose in CT—report of AAPM Task Group 23 of the Diagnostic Imaging Council CT Committee. American Association of Physicists in Medicine Website. www.aapm.org/pubs/reports/rpt_96.pdf. Published January 2008.
2. Information from vendors.
3. ICRP, 2007. The 2007 Recommendations of the International Commission on Radiological Protection. ICRP Publication 103. Ann. ICRP 37 (2-4).