Radiation detectors can be expensive and cumbersome. Here's one alternative, now on the market: Polaris-H, a University of Michigan project that offers handheld gamma-ray vision. 

To use the camera, someone looking for radiation sets it down in a room. (Carefully, I assume.) They can then connect it to an external touchscreen, piloting the camera as it lays a radiation map over an image of the room. Unlike some other detectors, the creators say, the Polaris-H operates well at room temperature, as opposed to detectors that require cryogenically frozen components. Other scanners are simply non-imaging, meaning they have to be carted around to see different parts of the room. Plus, they run for "below $100,000," according to a press release from the university.