Evaluation of Radiation Dose in Computed Tomography, Single Photon Emission Computed Tomography and Planar Radiography

Abstract

Diagnostic radiology is invaluable for the health care but due to the radiation risks, radiation protection of the patient becomes an important issue. Justification of the procedure and examination of the investigation are essential principles for patient protection. Therefore, ionizing radiation should only be used in those situations where it brings more good than risk. This study intended to (i) evaluate patient radiation doses levels during computed tomography(CT) and Nuclear medicine procedures, (ii) assess radiation doses during renal scintigraphy (Tc-99m-DTPA), Computed tomography urography (CTU) and intravenous urography (IVU) and to (iii) reduce the radiation doses during CT chest and abdomen procedures. A total of 1174 patients were evaluated using Orbiter 37 Gamma camera single head, Nucline Gamma camera (Medison) , dual slice and 64 CT scanner conventional X ray machine with computed radiography (CR) processing unit. Patients' radiation and effective doses were estimated using the administered activity, DosCal software, and dose length product (DLP) value for renal scan, IVU and CTU procedures, respectively. Patients’ effective doses during renal scan, CTU and IVU procedures were 0.78±0.18 mSv, 2.53±0.94 mSv and1.81±0.20 mSv, respectively. Patients were exposed to a higher effective dose during CTU compared to other two procedures. Patient doses depend on the size of patient, the type of scanner and the imaging protocol used. Effective doses considered low compared with previous studies. Patient doses were exposed to unnecessary radiation. Therefore, optimization could be achieved through optimal selection of exposure parameters will reduce the dose to its minimal value.