Diana Litmanovich MD, Presenter: Nothing to Disclose

1) Review range of radiation exposure with common CTPA studies. 2) Become familiar with principles of radiation dose assessment in CTPA 3) Become familiar with tools for dose reduction, recording the dose and auditing.

CT radiation exposure has received much attention lately in the medical literature and media, given its relatively high radiation dose per examination. There is a variety of possible strategies to reduce radiation exposure from CT in an individual patient. Optimal scan acquisition requires understanding by the radiologist of new scanner technology and implementation of the most effective methods available for dose reduction while maintaining image quality. Cardiothoracic imaging should be performed according to As Low As Reasonably Achievable (ALARA) principle. CT radiation dose metrics including CT dose index, Dose–length product, effective diameter and size-specific dose estimate are discussed. CT scanner parameters directly and indirectly influencing radiation dose, such as scan length, x-ray tube output, tube current modulation, pitch, image reconstruction technique (including iterative reconstructions), and noise reduction are also discussed in relation to the major MDCT scanners available. The goal of radiation dose reduction is to decrease the radiation dose delivered to the patient. For CT pulmonary angiography, restricted length of scanning, increased pitch, decreased kVp to 100 in the vast majority of patients, and application of automatic exposure control would provide the best combination. Noise reduction techniques afford additional radiation dose reduction. All the parameters are presented according to their respective importance to image quality and the implications of parameter changes on image quality and diagnostic content.  

Litmanovich, D, Optimizing CTPA: Radiation Dose Reduction.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14000781.html