The feasibility of vision-supported computer-based training in digital mammography

Introduction

Full-field digital mammography (FFDM) screening necessitates training more users to interpret digital images, as well as facilitating computer-based training employing a range of display devices. The feasibility of training naïve observers to examine mammographic images using different forms of vision-supported training on a PC monitor was examined.

Methods

A set of recent screening cases were first examined by an experienced radiologist and both his visual search behaviour and verbal commentary recorded. Twenty naive observers were then familiarised with abnormal mammographic appearance, concentrating on masses and calcifications. They were then split into four different training groups (examining mammographic images with: overlay of the radiologist's visual search; playback of the radiologist's commentary; mammographic regions of interest highlighted; or only regions of interest presented) using 20 two-view cases and a control group. Before and after training, each participant was tested on a set of 21 cases and required to identify whether an abnormality was present. Participants' eye-movements were recorded and a 21'' LCD monitor was used throughout to view the images.

Results

Examination of visual search and performance data, pre- and post-training, indicated that only 14% of responses identified the correct features and their locations. Errors were due to search (>60%), detection (<20%) and interpretation (<18%) factors. Approaches that emphasised the region of interest around an abnormality caused observers to fixate these areas for longer periods and produced fewer errors.

Conclusion

The introduction of FFDM allows a variety of displays and computer-based approaches to be used for training purposes.