This X-Ray image was made using a highly modified Scanmax 20 X-Ray mail scanner that I found via eBay (yes, really). I have substantially altered the imaging system; it now comprises a Kodak Lanex Fine fluorescent screen and a Nikon D3100 camera, replacing the original high brightness, low resolution screen and video-based image capture and display. The result is a dramatic increase in resolution, though at the expense of brightness. I usually use 6-second exposures using a 50mm f/1.4 lens stopped down to about f/2.2.
Images are further improved by post-processing multiple captures, usually simply averaging to reduce noise. There is some residual noise, of course, but it would take many more exposures (several dozen) to make any significant improvement in signal to noise ratio or resolution.
Please, please, please don’t think that you can just get an X-Ray machine off eBay or wherever and safely start making images like this. Without proper shielding and other precautions, ionizing radiation such as X-Rays can be seriously hazardous to your health.