Pioneers and history of Japanese neuroradiology.

Prof Makoto Saito and Prof Kentaro Shimidzu were the two most important pioneers in Japanese neuroradiology. They were also pioneers of Japanese neurosurgery who established neurosurgery as a subspeciality from general surgery. Both professors graduated from Tokyo University School of Medicine, in 1915 and 1929, respectively. Both trained at the First Department of Surgery at Tokyo University Hospital but never worked together, because Prof Saito became a professor of surgery at Aichi Medical College, before Prof Shimidzu started his training in the same department. However, in the final years of their careers, they collaborated to form the Japanese Society of Neurosurgery in 1948, and both contributed to the development of cerebral angiography. In those days, diagnostic radiology was performed by clinicians, and neuroradiologic practice was carried out by surgeons and internists. Radiologists were mostly interested and engaged in radiation therapy.