Abstract
The purpose of this work was to compare two methods used for effective dose (ED) calculation in conventional diagnostic x-ray examinations and to analyze effective dose distributions among radiological departments under study. The study was performed in four major hospitals in Khartoum area, Sudan, covering eight x-ray units and a sample of 325 patients. Two approaches were used for effective dose calculation:
In the first approach, the entrance surface dose (ESD) values were estimated from the x-ray tube output parameters for chest PA, Skull AP/PA, Skull LAT, Pelvis AP, Lumbar Spine AP and Lumbar Spine LAT examinations. The ED values were then calculated from the obtained ESD values using NRPB-SR262 Monte Carlo data and XDOSE software.
In the second approach, the energy imparted to patients in the same x-ray examinations was computed using values for entrance skin exposure, half- value layer and exposure area. Effective doses were then calculated from energy imparted using ED conversion factors proposed by other authors.
The results of ED values calculated using the two approaches were in good agreement between themselves and with data reported in the literature.
The mean ED values calculated using the Monte Carlo data and XDOSE software were found to be 29.9, 44.1, 8.91, 232.5, 224.5 and 93.6 mu Sv for chest PA, Skull AP/PA, Skull LAT, Pelvis AP, Lumbar Spine AP and Lumbar Spine LAT examinations, respectively. Almost all ED values were below the corresponding DRLs established elsewhere, except for chest PA examination which exhibited comparable mean ED values. The study is expected to increase the awareness among the medical professionals and members of the public on the status of radiological protection in Sudan.