Patient Dose-Area Product (DAP) Monitoring in Digital Radiography

The objective of this study was to determine the Dose Area Product (DAP) for sample of 70 patients (40 Females and 30 Males) undergoing different types of digital radiography (DR) examinations at King Abdul-Aziz University Hospital (KAUH), Saudi Arabia. This study was done through implementing a quality control (QC) program initiated by The Center for Training and radiation protection, KAU. It was found that, the majority of the examinations carried out at the university hospital were Chest (46%), lumbar spine (13%), knee (10%), wrist lateral (6%) projection, and the rest for the other projections. For the most frequent value in this survey (Chest PA) the measured dose area product ranged from 0.12 to 0.42 Gy.cm2 with an average value of 0.24 Gy.cm2, for Chest lateral, it ranged from 0.18 to 1.48 Gy.cm2 with an average value of 0.65 Gy.cm2. For Cervical spine the observed DAP values ranged from 0.1 to 0.38 Gy.cm2 with an average value of 0.23 Gy.cm2. For Lumbar spine the value of the DAP ranged from 2.14 Gy.cm2 to 2.93 Gy.cm2 with an average value of 2.44 Gy.cm2. The highest average DAP value (2.44 Gy.cm2) was obtained from lumbar spine projections. The results indicate that, the results of this survey were within the corresponding international values available from the literature. Some additional measures needed to reduce the dose without loss of image quality especially for lumbar spine protocol. Monte Carlo technique was used to calculate the conversion factors that estimate the effective dose used for measuring the DAP or entrance skin dose.