The periodic tuberculosis checkup, done massively in the years of SFRY. They had buses with equipment, which was an x-ray machine with a single burst, which was shot on a camera with 60x60mm film. It was lungs only, of course.
It was done periodically, by year of birth. I think I got checked perhaps three times altogether. The bus was once downtown, twice at Lesnina.
17-II-2021 - 15-IV-2026