I remember arriving at Manchester late one winters evening about 19 to 22 years ago and as I came out of customs in Terminal 1 there was a guy with a camera on a tripod and a TV set by the side. Intrigued as to what he was doing I asked him and he replied 'trialling a body scanner'. He very obligingly gave me a demonstration on a following passenger. Very impressive, you could clearly see the shape of quite a number of items being carried in the passengers various pockets but no personal details.
I would expect significant improvements to have been made since then unless the project was shelved.