Biomaterial Database

Prospects for x-ray exposure reduction using rare earth intensifying screens. 1976

R F Wagner, and K E Weaver

From measurements of screen-film sensitometry, Wiener spectra, and x-ray spectra, the speed, mottle, and quantum efficiency of several rare earth screen-film systems have been characterized. These systems offer exposure reductions of from two- to tenfold over conventional calcium tungstate systems. At the slower end, the noise (mottle) and resolution are comparable to what is available with conventional systems. Moreover, films designed to be used in such systems can be made with significantly lower silver content. As the speed advantage is increased from two- to genfold, however, the mottle also increases.

UI	MeSH Term	Description	Entries
D007811	Lanthanum	The prototypical element in the rare earth family of metals. It has the atomic symbol La, atomic number 57, and atomic weight 138.91. Lanthanide ion is used in experimental biology as a calcium antagonist; lanthanum oxide improves the optical properties of glass.
D008674	Metals, Rare Earth	A group of elements that include SCANDIUM; YTTRIUM; and the LANTHANOID SERIES ELEMENTS. Historically, the rare earth metals got their name from the fact that they were never found in their pure elemental form, but as an oxide. In addition, they were very difficult to purify. They are not truly rare and comprise about 25% of the metals in the earth's crust.	Rare Earth Metal,Rare Earth Metals,Earth Metal, Rare,Earth Metals, Rare,Metal, Rare Earth
D013679	Technology, Radiologic	The application of scientific knowledge or technology to the field of radiology. The applications center mostly around x-ray or radioisotopes for diagnostic and therapeutic purposes but the technological applications of any radiation or radiologic procedure is within the scope of radiologic technology.	Radiologic Technology,Technology, Radiological,Radiological Technology