Measurement of Radiation Doses in Computed Tomography (CT) and Estimated Radiological Risk of Cancer |Biomedgrid

The abundant observance of CT in medical diagnosis delivers higher radiation doses to patients than other radiological imaging systems which is a great concern for the increased radio sensitivity of certain tissue and radiation related cancer. In the present measurement, we have investigated patient effective doses by CT examination to Neck, Lung, Abdomen and Pelvis and a comparison is also made for the contribution of doses with digital radiography (X-ray) using Alderson Rando Phantom at the tube potential 80 kV-120 kV. Effective Dose (ED) measured using Entrance Surface Dose (ESD) for Neck were ranged from 0.30 mSv to 0.69 mSv, for Lung 0.65 mSv to 1.66 mSv, for Abdomen 0.99 mSv to 3.07 mSv and for Pelvis 1.16 mSv to 3.32 mSv, and the corresponding EDDLP measured using dose-length product were ranged from 0.45 mSv to 1.52 mSv for Neck, 1.99mSv to 6.76 mSv for Lung, 2.14 mSv to 7.51 mSv for Abdomen, 1.70 mSv to 5.95 mSv for Pelvis which lie within the reference level established by some other international institutions. From the present study it is found that CT doses is remarkably higher than digital X-rays i.e. for example; CT dose is 6.2 times higher than that of digital radiography at the same tube voltage 120 kV X-rays for neck imaging. The estimated risk factor and incident per population for both X- ray and CT are presented. It is observed that risk factor decreases with the increase of age and risks were increased with the increasing number of exposure.