The magic of math: three-dimensional X-ray vision

Speaker: Professor Samuli Siltanen, University of Helsinki

Abstract: X-ray images were invented in the late 19th century and immediately found applications in medicine: bone fractures could be easily seen in radiographs. In the1970’s a new X-ray based innovation was introduced. Tomography, or slice imaging, revealed the inner structure of a patient point by point as a three-dimensional map of tissues. This opened up a new world for doctors as they could do precise diagnosing based on these “CAT-scans.” Tomography is based on recording X-ray images of the patient along many directions, and then using mathematics in a clever way for combining the information into a 3D image. This talk explains that process in simple terms. An important research topic in modern mathematics is to look for a way to do tomographic imaging with the least possible amount of radiation dose to the patient. Or to compensate for incomplete measurements caused by restrictions in the imaging arrangement. This is based on a process called regularisation, also illustrated in the talk in an easy-to-understand way. Also: there is a fun quiz revealing natural tomographers among the audience.

Please note: This lecture is preceded by the Annual General Meeting of the DMF (Danish Mathematical Society). Everyone is welcome at the talk (but only DMF members can vote at the DMF AGM. If you're not a DMF member, sign up today: https://mathematics.dk ).