One of my best friends was a NUPOC(?) officer in the navy, he was stationed on the Abraham Lincoln her reactors were installed and went through her sea trials there. He was having problems with his hip for some reason and the Dr’s did a test where they injected him with a low level radioactive fluid to see what was going on. He went back to work and later in the day had to use the head. When he peed it set off the radiation detectors, to this day he still laughs that somewhere, buried in some deep lined pit wrapped in plastic, is the urinal cake he whizzed on.
I understand the humor but for those who don't, it probably isn't so. They probably used 99mTc as a tracer for imaging, and that has a six hour half-life.
I had a heart scan a few years ago and thy used about 30 millicuries of 99mTc. I went in to work that afternoon and was setting off radiation alarms whenever I walked by. I did a gamma spectrum of my chest using a high resolution gamma spectrometer and saw they characteristics gamma energies from the 99mTc. It was still in there. By the next day, it was gone (decayed or metabolized and pissed out).