Design of a database with graphical analysis for X-ray quality assurance and dose information to assist in a...

A database system has been set up on an IBM PC to store X-ray quality assurance (QA) data and patient doses for all X-ray equipment operated by Grampian Health Board. Graphical analysis facilities have been developed to display data in a readily understandable form. Data on equipment specifications, QA test results, exposure factors for standard examinations, and thermoluminescent dosemeter (TLD) measurements of patient skin doses are stored in separate forms. X-ray machine outputs are fitted to a simple polynomial equation, and the data combined with information on exposure factors to calculate entrance doses for selected examinations. Data such as filtration and backscatter factors are derived from look-up tables for use in dose calculations. Histogram comparisons can be made between calculated doses, means of TLD measurements and National Radiological Protection Board reference levels to allow units giving high skin doses to be identified so that corrective actin can be taken.