1.) Understand that CTDI is merely a technical concept for scanner acceptance and constancy testing, but not a measure for patient dose. 2) Learn about concepts for patient- and scanner-specific patient dose estimates. 3) Learn about the concept of diagnostic reference levels and its strengths and weaknesses.
There are no common regulations valid for all of Europe, but there are a number of initiatives and concepts in place which originated here. Among these are primarily the generation of conversion coefficients k for estimating values of the effective dose E from the dose length product (DLP) by E = k×DLP and the concept of dose reference levels (DRL). DRLs for radiological examinations in the European Union were demanded by law in 2000. DRL values are considered advisory and aim at identifying practices with dose levels exceeding the 75 percentile level of reference distributions. Member states have installed the concepts and specific values to different degrees. A drawback is that both the values of k and DRL relate to CTDI and DLP.
There is no major debate regarding the validity of the computed tomography dose index (CTDI) because it is mostly considered as a tool for scanner acceptance and constancy testing. Its use for that purpose is undisputed. More accurate measures for patient dose are still to be established in an international consensus.
The lecture will review the above concepts and will point to both strengths and weaknesses.
http://media.rsna.org/media/abstract/2012/12021229/bxfw635_12021229_RC123B_Kalender_cp.pdf
Kalender, W,
The European Perspective. Radiological Society of North America 2012 Scientific Assembly and Annual Meeting, November 25 - November 30, 2012 ,Chicago IL.
http://archive.rsna.org/2012/12021229.html
