Useful links
How radiology works - an extensive collection of articles and online videos about the physics and mathematics of x-ray imaging. Recommended!
https://howradiologyworks.com/
https://www.youtube.com/channel/UC3MTvd6kJizu7S_2-lyPXuA
An Interactive Guide To The Fourier Transform
https://betterexplained.com/articles/an-interactive-guide-to-the-fourier-transform/
Nuclear physics for medicine
http://www.nupecc.org/npmed/npmed2014.pdf
The Fourier Transform and its Applications
https://see.stanford.edu/materials/lsoftaee261/book-fall-07.pdf