THE EFFECT OF THE IMPLEMENTATION OF THE QUALITY CONTROL PROGRAM OF THE COMPUTED RADIOGRAPHY SYSTEM

Abstract

Objectives: To study the relationship between the patient radiation doses, the image quality and the repeated and rejected rates both before and after the implementation of the quality control (QC) program to the computed radiography (CR) system at the Outpatient Division, Department of Radiology of King Chulalongkorn Memorial Hospital, Thai Red Cross Society.

Materials: Two systems of single-phase x-ray machine (Hitachi model DR-155HM), and another system of the CR system (Fuji model FCR 5000) with standard type of imaging plates, QC accessories, CR workstation with high resolution display system were compared.

Methods: Experimental prospective study, before and after QC program to the CR system were designed; 1,384 examinations of the adult patients, eight projections of CR images, skull PA, lateral cephalometry, cervical spine AP, chest PA, abdomen AP, lumbo-sacral spine AP and lateral and pelvis AP were performed under patient consent form and calculated the entrance skin dose (ESD). The radiographic patient dose was defined as the comparison of the rejected and retaken rates for the before and after QC of equipment. CR image quality evaluation had been done by two of the equivalent experienced radiologists.

Results: There were the significantly differences (P < 0.05) for the decreasing of the rejected and retaken rate and the decreasing of average of ESD after the implementation of the QC program of the CR system.

Conclusion: After the implementation of quality control program for the computed radiography system, the reduction of the rejected and retaken rate was 55 percent and the reduction of the entrance skin dose was 18 percent in PA chest and 16 percent in the lumbo-sacral spines while maintaining optimum image quality. The QC program of the CR system shows the useful parameters benefited for the optimization of the patient doses and the image quality.