The material  presented in this publication was originally  prepared for the Cornett-Assess project, a program to develop health technology assessment activities with industrial organisations in Europe, which was supported by the European Community. The case study evolved as an approach to a self-guided instruction course on the assessment of a particular  area of diagnostic technology. It has been issued as a working paper in view of continuing interest in non-laboratory pathology testing. The diagrams  prepared for the self instruction course have been included  in an appendix.

A shortened version of this material, together with chapters by contributors to the Cornett-Assess project on a number  of other topics, will appear  in Assessment of Health Care Technologies: Case Studies, Key Concepts  and Strategic Issues (A. Szczepura  and J. Kankaanpaa, Eds), to be published by John Wiley, London, during 1995.