Yes - more or less. Laboratory implies that the room will be used to analyse the X-Rays after they've been taken [a place using X-Rays for research, such as a Physics department, would also have a laboratory, for example]. Technically, using the word 'room' implies only that the X-Rays will be *taken* in there, not procressed/analysed as well.
But it's really a technicality - no-one would bat an eyelid if you used them interchangeably.