Re: Do objects that show up on X-Rays Photos Absorb or Reflect X-rays

>When taking an X-Ray of something, do the things that show up on the 
>x-ray, i.e. the bones, metal, etc.  Reflect the X-rays or do they 
>Absorb Them, and if they absorb them, wouldn't the bone or material 
>then increase in temperature, if so, is it such a minimal amount that 
>it is unnoticable to the person getting X-Rayed?

Excellent question. It sounds like you are thinking quantum mechanically.
Xrays are absorbed by the different tissues of the body to different 
degrees. Bone (or other metal) and any other calcium containing tissue 
absorb xrays best. Tissues that are primarily water(muscle) absorb xrays 
less than bone but more than fat, while air(lung) absorbs them the least. 
The portion of the xray film that gets the highest dose of xrays will 
become black after it is developed. The bones in a properly exposed and 
developed film will be white because they got relatively little radiation 
exposure.

You are correct in thinking that xrays "deposit" energy into the tissues 
where they are absorbed, and they probably do heat them up a little bit. 
The degree of heating is not detectable, however. The higher doses of 
radiation for treatment purposes cause damage to the nuclear structures, 
not by heating them, but by ionizing molecules and creating damaging 
chemical reactions in chromosomal DNA. There is probably some of the same 
damage during diagnostic xrays, but the cells have mechanisms for repair of 
low level chromosomal damage.

There is some scattering of xrays by tissues which can cause haziness of 
images. This occurs when the path of an xrays is only deflected, not 
stopped. The haziness can be reduced by a metallic grid of numerous thin 
metal sheets oriented parallel to the beam of the xray source that absorb 
xrays which have been deflected and are coming at angles from the sides. 
They let pass the xrays that have passed directly through the subject. 
These grids are used when the area of the body is thick, an example being 
abdominal films.

David Winsemius, MD