Performance differences across the Atlantic when UK and USA radiologists read the same set of test screening cases

Two groups of experienced radiologists from the UK and the USA read the same set of 40 recent FFDM screening cases to examine the effects of mammography experience, volume of cases read per year, screening practice and monitor resolution on performance,. Sixteen American radiologists reported these cases using twin DICOM calibrated monitors which were half the resolution of the clinical mammographic workstations used by 16 UK radiologists. In terms of effects of volume of cases read per year, then when the group of American radiologists were split into high and low volume readers (using 5,000 cases p.a. as a criterion) no difference in any performance measure was found. This may be partly explained by the fact that they were all were very experienced which may have counteracted any case volume effect here. Comparing the two groups of radiologists from both countries, then the UK group performed better in terms of the number of cancers detected although the American group recalled more cases, despite having poorer monitors. This reflects differences in clinical screening practice between the countries, however differences simply due to the reporting monitors used cannot be ruled out. Data from the study were also compared to that from all UK screeners who had read these cases as either soft copy or as mammographic film.