Gamma Cameras
Qualitative resolution
This test is performed using a large flood source, such as the Co-57 or Tc-99m flood tank shown earlier, along with a bar phantom. The bar phantom is a large plastic sheet which contains a number of lead bars. It is split into four segments made of differing, known widths of lead. An image of the phantom is produced by placing the bar phantom on the camera and with the flood source on top. The image is assessed by observing the number of sections in which the lines can be clearly seen. Since the clarity of the lines will depend on the noise in the image the total number of counts acquired has to be kept constant. This allows serial images to be compared. This image is also an easy way to asses non-linearity.
