Mammography soft-copy reading: to digitise priors or not, that is the question

Evidence is accumulating on the use of digital mammography. But there is relatively little published guidance on how to manage hardcopy film-screen prior images in a soft-copy reporting environment. For a population screening program, one pressing question is 'to digitise priors, or not?'.

The BreastScreen Victoria programme screens 200,000 women each year, with two-view mammography at 2-yearly intervals. Many women have completed their fifth round of screening. Ten million films are archived. Existing standards require independent double-blind reporting comparing prior and current images. As digital is introduced, each reader needs to compare soft-copy images with hard-copy priors. How do we merge the two different reading worlds, analogue and digital, or indeed should we even attempt this?

Possibilities include digitising; using a special multi-viewer; using a dental viewing box; or loading an analogue multi-viewer alongside the soft-copy 5 MP monitors. Factors specific to digitising include the following: Is it possible to digitise in such numbers? Is it too time consuming or too expensive? What resolution should be used to digitise? Is the quality of digitised priors sufficient for comparative review? This poster traces the decision-making process to digitise prior images in the context of a digital mammography pilot within BreastScreen Victoria.