A Mathematical Approach Evaluation of Dose Area Product (DAP) Using to Patients Undergoing Intravenous Urography Examinations in Addis Ababa, Ethiopia

Abstract

Patient dose evaluation is one of the quality assurance programs. Dose area product is a product of surface area of patient that exposed to radiation at the skin entrance multiplied by the radiation dose at the surface. This research focused on a dosimetry, DAP, for specific X-rays examination which is known as Intravenous Urography examination. A cross-sectional study was conducted on 145 adult patients age above 16 years examined using IVU in Addis Ababa, Ethiopia at two public and two private hospitals during February 2012-March 2012. The type of X-ray tubes with their outputs (measured using Unfors Ray Safe XI R/F detector) and the exposure parameters for each patients were recorded. The DAP to patients were estimated using mathematical equation. The recorded data was analyzed using statistical software. It was obtained that mean DAP (Gy cm2) per examination within hospitals ranged from 13.7 Gy cm2 to 32.9 Gy cm2. The mean value of this study DAP (24.7 Gy cm2) per examination which was greater than most of the published results and National diagnostic reference levels. These insure that the Intravenous Urography performed in the some of the hospitals were not capable of acceptable dose levels for patient safety. Therefore, to achieve a lower value of DAP per examination to a patient; a quality assurance program should be done in the hospitals to minimize the number of films per exam and to use appropriate exposure factors to get quality radiographic image for diagnosis.