This let surgeons attend patients spouting blood without removing their coats an important distinction that set them apart from shirt-sleeved tradesmen of the lower orders.
This approach has the advantage that the tissue has a functioning system of blood vessels to deliver nutrients, so it should be possible to grow tissue cultures more than a millimetre thick the current limit.
This, too, can be hyperpolarised but, unlike 3He, it can also be absorbed by blood, and can thus get into the rest of the body, an effect that may be useful for other types of diagnosis.