There are currently few commercially available clinical products with neural network components-in fact only one has gained FDA approval, and none have yet been certified by the MDA. A major step in the certification process is proving the integrity of the neural network component, which cannot be done by reference to substantially equivalent certified products because they do not exist. Consequently, the case for the use of the new technology has to be made explicitly, by recourse to best practice in its design and evaluation. This paper discusses the use neural networks in medical applications, with reference to a case study from magnetic resonance spectroscopy (MRS). (5 pages)