MB ChB Edin 1971; FRCR 1978; DMRD Edin 1975.
Turnbull was consultant neuroradiologist to North Manchester General Hospital and Booth Hall Children's Hospital. He had previously held radiological appointments at Edinburgh Royal Infirmary and Southampton General Hospital. Turnbull was also part time lecturer in the department of diagnostic radiology at the University of Manchester. He was a fellow of the Royal Society of Medicine, founder member of the British Society for Interventional Radiology and member of the British Society of Neuroradiologists.