Misleading Results with a Bar Phantom Image

Abstract

A bar phantom was imaged in an attempt to measure the resolution of a scintillation camera with a high energy collimator. The image obtained was actually a Moire pattern but it caused some confusion; it resembled a bar phantom image because it had the appearance of different sized bands in different quadrants. On closer examination the image was found to be due to interference patterns between the lead bars and the array of holes in the collimator.