My wife and I needed to go to Deaconess Hospital to visit a relative. Hate to admit it, but I always welcome the idea of going to a hospital, not as a patient, or to visit a family member, but to find radiation. There are rooms with radioisotopes, xray machines, and of course radioactive patients. I have no desire to break into any of these areas either, it is interesting just to see where they can be detected.
When we entered the hospital we went to the sixth floor, unfortunately in the wrong wing. There where plenty of closed offices, no rooms, and a notably low background radiation count, about 5 uR/hr. My wife and I needed to go to the North Side of the hospital.
On our way back down the elevator to the ground floor we passed through the surgical center (again roughly 6 uR/hr), and then as we walked further the alarm on my PM1703M started vibrating. The measurement was between 11 and 13 µR/hr. The first sign on a door read "Bone Density Lab" and then other signs read "Medical Imaging." We passed into a lobby and the count dropped down to 7 µR/hr. We went to the sixth floor, and there where no other alarm events.
After our visit we walked back through the same halls and there were no alarms or abnormally high readings. Measurements where all around 7 uR/hr, with no alarms.
This leads me to speculate that what I may have picked up was a CAT Scan. Normal X-rays may only last a second or two. CAT Scans can last as long as 90 minutes, so the xray tube may energized for a much longer period of time. I would also suspect that medical isotopes would generate a radiation field that would be more persistent then I encountered.
Overall, the experience was sort of disappointing. I have found higher radiation readings at stores and on the city streets! However, it does speak highly of the radiological health of the hospital building. The CT Scanner must be well shielded, and the hospital must take great care where they store medical radioisotopes.