Correlation Analysis of the Estimated ESD in Routine X-ray Diagnostic Procedures at a Local Level in Bosnia and Herzegovina

摘要

Health centers in small towns in Bosnia and Herzegovina do not have DAP facility or TLDequipment so that the estimation of entrance surface doses (ESD) could be performed merely from Tube OutputMeasurements. The goal of this work is to evaluate ESD at a local level in X-routine diagnostic radiologyprocedures for standard adult patient, including correlation analysis and comparison the results obtained with therecommended diagnostic reference levels. In a small health center such as the Banovici Health Center in theTuzla Canton, the measurements were focused to high-frequency X-ray examinations: chest (PA) and lumbarspine (AP, Lat). The results obtained indicate that the deviations between ESD values of two radiologistsemployed in the Banovici Health Center are mostly due to very large exposure time during the examinationsdone by the one of radiologists. The value of cross-correlation coefficient between the ESD for chest PAexamination of –0.75 indicates that one data set has a negative linear relationship to another data set. Ahistogram of the result, obtained by the bootstrap procedure establishing the uncertainty of the quantity,represents strong quantitative evidence that both ESD data set are negatively correlated. Also, the correlationcoefficients of 0.12 and 0.41, for the LS examination in PA and LAT projections, respectively, do not indicatestrong linear relation between data set of both radiologists. It was performed ANOVA for comparing the meansof two radiologists data set for the chest AP examination. The very small value of p=1.09*10~(-7) indicates thatdifferences between the two chest ESD results are highly significant. However, p-values of 0.17 and 0.35obtained for LS-examinations in AP and LAT projections, respectively, suggest that the sample means are notsignificantly different. The results indicate that adequate measures should be taken for the benefit of the patients.