Radiologists have long been interested in imaging and measuring blood fl ow and in
characterising the structure of blood vessels within pathological tissues. In 1927 Egas
Moniz described the technique of cerebral angiography using injection of radio-opaque
contrast agent combined with conventional radiology. His earlier published work had
focused on the physiology of sex, so the fact that dynamic contrast imaging was able to
divert him is a testament to the excitement intrinsic to the topic. Perhaps it is worrying
that he later went on to invent the technique of prefrontal lobotomy – one can only hope
that it was not his frustration with dynamic contrast imaging that drove him to it.
More seriously, it soon became obvious that dynamic contrast imaging using conventional
radiography (i.e. angiography) was an enormously powerful clinical tool for
the identifi cation, localisation and characterisation of a wide range of pathological tissues.
This was especially true in the head, where alternative radiological tools were not
available, and in vascular and malignant lesions. The angiographer became a mainstay
in many areas of diagnosis, and numerous articles were subsequently published on the
characterisation of tumours based on their angiographic appearances. Even in these
early days before the Second World War it was clear that classifying tumours based
on the number of blood vessels, the density of capillaries, the rate of blood fl ow and
the extent of contrast leakage provided valuable, and at the time unique, information,
although these classifi cation methods remained purely subjective.