Assessment of Radiation Dose and Image Quality in Computed Tomography

Abstract

This descriptive cross-sectional study aimto assess the radiation dose and image quality in CT in order to explore the potential risk of radiation. This study was conducted on three hospitals during the period from 2015-2019 in Khartoum state .CT machines were used to collect data during this study the manufacture General Electric ,Toshiba and General Electric respectively Detector Type 16,16 and 64 respectively, where the Computed Tomography Dose Index(CTDI vol) mGy,Dose LengthProduct( DLP)mGy.cm, Size specific dose estimate (SSDE)mGy and effective dose (in mSV) were measured for each hospital representing the scanning of head, chest and abdomen as well the image quality that include noise, signal, signal to noise ratio and contrast in high and low intensity areas in CT scan images for the previous parts before and after image enhancement. The main results of this study showed that the maximum CTDIvol was to the head 60.5mGy, the highest DLP was for the abdomen 2121.45mGy.cm, to SSDE was 61.71(mGy) for head as well as the effective dose which is equal to 5.65mSV.alsothe study showed that the image quality in the body areas of high intensity and low intensity before and after the image enhancement is associated with linear relation as the recession coefficients could be used to estimate the values of image enhancement before processing in order to find out the image quality ,and possibility of using the method to decide the best method of image enhancement.The study concludethat, The Effective dose is higher in hospital3 than other hospitals and SSDE dose is higher in hospital2 than other hospitals. And evaluated effective dose in every Exam type is higher brain than other exams, andthe following linear equation can be used to estimate the validity of enhancement before the process which as signal after enhancement (High intensity area) = (1.31× Signal) - 64.5, noise after enhancement (Low intensity area) =(0.824× noise) +0.278 and Signal to noiseratio after enhancement(HIA) = (1.07× SNR) -3.4. Contrast after enhancement = (0.853×contrast) +16.7. This study recommended that CT scan examination for any patient must be justified, QC program are essential to evaluate the patients dose and machine accurate performance, Future studies can be done in order to optimize the radiation dose to establish national diagnostic reference level in Sudan and Application of QC program as a routine task in all x-ray department in order to detect possible future problems.