SMY:n etäkollokvio 17.4.2024

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

Recording of the talk now available on YouTube


Time and place: Wednesday, April 17 at 16:15, over Zoom and in colloquium watch events at mathematics departments (see bottom of the page)

Speaker: Samuli Siltanen, University of Helsinki

Chaired by: Mikko Salo, University of Jyväskylä

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


In the 1970’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. 

Samuli Siltanen kasvokuvassa
Samuli Siltanen works as professor of industrial mathematics at University of Helsinki. He designs algorithms for medical imaging and other applications, and communicates science to general audiences.


Where to watch?

The colloquium was broadcast over Zoom on Wednesday, April 17, at 16:15.

In addition there were colloquium watch events at most Finnish universities' mathematics departments. See the list below for the location of your own department's event:

  • Aalto University: Hall M1 (Otakaari 1)
  • LUT University: Hall 1318 (Lappeenranta campus, third floor atrium)
  • University of Eastern Finland: Metria M301 (Joensuu campus)
  • University of Helsinki: Exactum A111 (Lars Ahlfors auditorium)
  • University of Jyväskylä: MaD302
  • University of Oulu: Lecture hall L9 (Linnanmaa campus)
  • University of Turku: Quantum M3
  • University of Vaasa: F425
  • Åbo Akademi: Aurum A316 Chromium

A recording of the talk is available on FMS' YouTube channel.