A low-contrast phantom for daily quality control.

A simple phantom is proposed to provide a low-contrast test object for daily quality assurance. The phantom consists of four quarters and five dimes taped to a Plexiglas plate. For daily quality control, the phantom is used with 5 cm of Plexiglas as scattering material and a flood source. Examples of images are presented for several gamma cameras, illustrating some of the information that can be obtained. In particular, we present examples of cameras providing improper imaging performance with the coin phantom but with "normal" floods and bar-phantom images. The major conclusion is that daily quality-control images should include significant of scattering material and low-contrast objects.