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AUTOMATED QUALITY ASSURANCE AND PATIENT DOSIMETRY IN DIAGNOSTIC RADIOLOGY

Objective

DEVELOPMENT OF A COMPUTERIZED METHOD FOR AUTOMATICALLY CONTROLER X-RAY TUBE AND GENERATOR PARAMETERS WHICH WILL BE USED FOR PERFORMING ONLINE QUALITY ASSURANCE AND PATIENT DOSIMETRY.
A series of measurements has been undertaken which indicates that the automated quality assurance and patient dosimetry system can measure a number of radiographic exposure parameters with comparable accuracy to standard techniques. The software for separate calculation of the radiation dose to the patient has been utilised to estimate retrospectively foetal doses for radiographic examinations. Dose estimates made using the computer program were comparable with those using manual calculations.
THIS PROPOSAL INVOLVES THE DEVELOPMENT OF A COMPUTERIZED METHOD OF AUTOMATICALLY MONITORING TUBE AND GENERATOR PARAMETERS TO PERFORM ONLINE QUALITY ASSURANCE AND RADIATION DOSIMETRY. THIS INFORMATION WILL BE STORED IN A COMPUTER DATABASE FOR LATER ANALYSIS OF THE CAUSE OF REPEAT EXPOSURES AND THE RADIATION DOSES RECEIVED BY PATIENTS. PRESENT PRACTICE IN QUALITY ASSURANCE IS TO MONITOR EQUIPMENT AT REGULAR INTERVALS AND HOPE THAT THIS SAMPLING RATE IS SUFFICIENT TO DETECT EQUIPMENT MALFUNCTIONS. THE ADOPTION OF ONLINE QUALITY ASSURANCE WILL CHANGE THIS CONCEPT, SINCE IT WOULD BE A CONTINUOUS PROCESS. IT IS NECESSARY TO KNOW THE EXTENT OF THE VARIOUS TYPES OF MALFUNCTIONING BEFORE QUALITY ASSURANCE CAN BE PERFORMED, USING A FEDDBACK TECHNIQUE BY UTILISING A MOCROCOMPUTER LINKED TO X-RAY EQUIPMENT.
QUALITY ASSURANCE WILL BE PERFORMED FOR EVERY X-RAY EXPOSURE BY COMPARING THE MEASURED TUBE AND GENERATOR PARAMETERS AGAINST THEIR RESPECTIVE NOMINAL SETTINGS WITHIN ACCEPTED VALUES. THE SOFTWARE WILL AUTOMATICALLY WARN THE OPERATOR IF ANY PARAMETER IS OUTSIDE A PREDETERMINED LIMITING VALUE.
THE DEVICE WILL ALSO ENABLE PATIENT DOSIMETRY PARAMETERS TO BE COLLECTED FOR EACH RADIOGRAPHIC EXAMINATION. WHEN THE PATIENT IS EXAMINED THE DETAILS OF THE TYPE OF INVESTIGATION AND PROJECTION WILL BE ENTERED ONTO THE DATABASE. IN ADDITION TO THE EXPOSURE-AREA PRODUCT, THE RADIATION OUTPUT IN AIR AND THE FIELD SIZE AT A GIVEN DISTANCE CAN BE DEDUCED. THESE DATA TOGETHER WITH THE INFORMATION ON TUBE POTENTIAL AND EXAMINATION-PROJECTION CAN BE USED TO DEDUCE THE PATIENT ENTRANCE SKIN DOSE USING APPROPRIATE BACK SCATTER FACTORS AND THE ENERGY IMPARTED. DOSES TO A NUMBER OF ORGANS WILL BE ESTIMATED USING NORMALIZED ORGAN DOSE DATA AND A KNOWLEDGE OF TUBE POTENTIAL AND FIELD SIZE. THIS WILL BE EXTENDED TO INCLUDE AN ESTIMATION OF RISK FROM BOTH THE EXPOSURE-AREA PRODUCT AND ORGAN DOSE CALCULATIONS. THE WIDESPREAD USE OF THIS DEVICE WOULD AUTOMATE THE ESTIMATION OF RISKS FROM MEDICAL EXPOSURE. IT IS ANTICIPATED THAT A SMALL SCALE PILOT STUDY IN A RADIOLOGY DEPARTMENT WOULD BE IMPLEMENTED, FOLLOWED BY A TRANSNATIONAL INVESTIGATION INTO THE USE OF THE DEVELOPED PROCEDURE. THE AIM OF THIS INVESTIGATION IS TO DETERMINE THE BENEFIT (QUALITY OF DIAGNOSTIC INFORMATION AND EXPOSURE REDUCTION) FOR THE PATIENT DUE TO THE INTRODUCTION OF AUTOMATED QUALITY CONTROL.

Funding Scheme

CSC - Cost-sharing contracts

Coordinator

Northern Regional Health Authority
Address
Westgate Road
NE4 6BE Newcastle Upon Tyne
United Kingdom