RADIATION EXPOSURE AND MEDICAL IMAGING

Abstract

During last three decades, a tremendous rise has been observed witnessed in utilization of multislice computed tomography (CT) and myocardial perfusion imaging (MPI) in nuclear medicine. It is expected to observe persistent rise in near future as hybrid imaging using PET/CT and PET/MR has become standard of care in many cancers. According to National Council on Radiation Protection and Measurement (NCRP) report published in 2009, in United States (US) over a period of 10 years (1998 to 2008) CT based procedures had increased from 26 million to 70 million and nuclear medicine procedures from 12 million to 20 million[i]. Importantly these numbers are almost 50% of the CT and NM (primarily MPI) procedures performed globally.  In 1980 mean radiation dose to an American was 3.6 mSv (3 mSv from background and 0.6 mSv from medical exposure) but in 2006 medical exposure (primarily CT and MPI studies) contributed 3 mSv¹. This trend and its aftermath indeed have created anxiety among various statutory and non-statutory bodies and obviously in public regarding stochastic effects of radiation like cancers and congenital abnormalities.