It is clear that Professor Takahashi understood the principle of modern CT in the 1950s, long before Godfrey N. Hounsfield reported the development of the first CT images in 1972.
“Dr. Shinji Takahashi was the first to advocate the basic concepts of CT in the 1950’s, and is a pioneer that Japan boasts about to the world. He constructed slice images by recording a sinogram of cross sections of parts of a human body onto a film and implementing optical back projection. CT imaging by Hounsfield, who won the Nobel Prize in 1978, was introduced in 1972, and Dr. Takahashi’s research work precedes it by 15 years. His detailed achievements are recorded in his English book titled “Rotation Radiography”, published by the Japan Society for the Promotion of Science in 1957. In praise of his magnificent work, in the 2012 issue of the English journal, “Radiological Physics and Technology”, we put his picture on the cover and summarized his life and achievements as an editorial article.”
“The term “rotation radiography” was used because the X-ray tube and the film were rotated around the subject to be examined through a certain point. “
“The term conformal radiotherapy was coined by Shinji Takahashi. Between 1948 and 1963 he published a series of papers on the use of rotation radiography and in 1959 began to apply these principles to radiotherapy. His seminal work, ‘Conformation radiotherapy: rotation techniques as applied to radiography and radiotherapy of cancer’, described the use of moving geared diaphragms and tables to irradiate irregular volumes. He described three basic techniques, ‘rotational body technique’, ‘column focus´ and ‘hollow-out technique’, which could be used alone or in combination.”
REFERENCES:
https://www.jsrt.or.jp/data/english/news/4480/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3258406/
https://rbc.inca.gov.br/site/arquivos/n_45/v03/atualizacao.html