274. Multi hospital experiences of Radiation Dose Index Monitoring (RDMI) in mammography

Abstract

Purpose Aim of this work was to use the dose index information from 5 mammography units within USL Toscana Centro, Firenze-Empoli area, analysing and comparing the compression force data and the AGD trend with the thickness of the compressed breast. Methods The RDMI data from Siemens Mammomat Inspiration mammography units were analysed by exploiting the information gathered in a local LOG file that records all the exposure parameters of each single shot. Data in the file are extracted in a spreadsheet tool. All the devices have the same kV-breast thickness compensation curve and work in AEC mode with a W/Rh combination. For the analysis, we focused on data for the year 2015–2016 covering about 40,000 patients for a total of over 169,200 projections. Data are filtered eliminating quality test and manual exposures, breast implants and surgical pieces. Results The average compression force values, for the year 2015, are similar in the first 4 unit. For the Unit 5, it’s found that the breast is significantly less compressed. After a training session on the correct use of the compression paddle, data for year 2016 were analysed. Since then, there are comparable forces with other devices. Nevertheless, for all mammography, there is a very large compression range, with maximum points greater than 200 N and values at the lower limit of 20 N. For the analysis of AGD vs thickness, all devices fall within the EUREF limit values (see Table). Conclusions Data collection has allowed to investigate and compare retrospectively all exams executed in the year 2015 −2016, evaluate anomalies not highlighted with quality assurance tests and take corrective actions to improve performance. Download : Download high-res image (128KB) Download : Download full-size image