Welcome to Classifications and Online Calculators in Radiology

This site was build along with the Atlas of Radiology Images to support your knowledge in radiology.

You will find here:

that are used in radiology and related fields with free access.


  • Some pages are accompanied by illustrations
  • All pages contain tags for easy navigation

The concept

The concept of this website is based on a previous site that was founded in 2008 and is still up and running. The website is composed as a book, where all sources are properly referenced, according to a good practice in scientific publications.

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    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


    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).

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