Abstract :
This story starts in 1951 when I finished my Ph.D. work in magnetism at Nottingham and became a Hospital Physicist at Liverpool under the late Tom Chalmers (of the Szilard — Chalmers nuclear reaction) and the late Russell Herbert. They showed me, at the very beginning of its use in medicine, how radioactive iodine localised in the thyroid gland and how, by moving a Geiger-Muller counter rectilinearly, centimeter by centimeter over the neck, one could appreciate the size and shape of the gland. In patients with thyroid disorders, tumours in the gland could be detected and localized because they were ‘cold’, in contrast to the surrounding ‘hot’ normal tissue [1]. I extended this contrast, provided by gamma-rays, when I went to Hammersmith Hospital, London, to detect and localize brain tumours by building a mechanized automatic scanner which had a quantitative colour-coded print-out [2]: a clinical accuracy of 85% was achieved [3], far surpassing the x-ray angiography technique of the time.
