Design Management Group

EMI CAT Scanner

The EMI CAT Scanner was a revolutionary medical imaging system developed by Godfrey Hounsfield at EMI. It used Computed Axial Tomography (CAT) to produce cross-sectional images of the brain by scanning a beam of x-rays from many different angles.

EMI had no track record in medical electronics but was sufficiently confident of the success of the product that it decided to invest in order to develop its own scanner business. The first scanner costing around £100k was introduced in 1973 and within 2 years, the scanner market was estimated at £40m.

This growing new market attracted new entrants from the ranks of established imaging companies, such as Technicare and GE. These companies were perhaps better placed to support such complex medical equipment. Although EMI had applied for a number of patents, this did not prevent the appearance of a number of competing machines, and by 1976, EMI had lost market leadership in the crucial US market.

CAT scanners were becoming 'must-have' pieces of equipment, but this was also placing strains on hospital budgets in the US. The US government therefore introduced the requirement for a certificate of need to control the number of applications for new scanners. This had the effect of halving the scanner market.

EMI was beginning to have difficulties in other parts of its business, notably music, and its share price started to come under pressure, making it a take-over target, In 1979, EMI was sold to Thorn. The new Thorn-EMI immediately rationalised and sold off the CAT scanner business to GE at a knockdown price.

Godfrey Hounsfield shared the Nobel prize for medicine in 1979 for the development of computer assisted tomography, and was knighted in 1981. He died in 2004.

Further information

• Hounsfield, G. (1979) Computed Medical Imaging, Nobel lecture, 8 December 1979
• Godfrey Hounsfield autobiography from nobelprize.org
• Mitchell, W. Playing Leap-Frog with Elephants: EMI Ltd. and CT Scanner Competition in the 1970s, University of Michigan case and teaching note
• EMI and the CT Scanner (A), (B) Harvard Busness School cases.
• Teece, D. (1986) Profiting from technological innovation: implications for integration, collaboration, licensing and public policy, Research Policy 15(6): 285-305
• Teece, D. (2000) Managing intellectual capital, Oxford University Press (click here for an excerpt)

All trademarks acknowledged.