Development of a simple test object for rapid assessment of fluoroscopic imaging systems

Performance assessment of fluoroscopic systems is done by different groups using a diversity of test protocols and phantoms. This project aims to use a single standard inex pensive phantom for non-invasive, clinically realistic testing acceptable to all test bodies in NSW: hospital physicists, Public Works department and Radiation Health Services personnel, fluoroscopic manufacturing company engineers, and radiographers. phantom and protocol have been developed to assess overall fluoroscopic image quality for clinical conditions. Previous image quality protocols used a prescribed setup (70 kVp, 1mm copper) which is not clinically realistic, and not possible on some units. This is especially the case with the increasing use of automatic brightness control (ABC). The proposed test protocol includes 20 cm water in the imaging phantom, allowing ABC setting of the relevant parameters. It has been found that x-ray beam quality and attenuation produced by the previous protocols differs significantly from that with clinical conditions using 20 cm water under ABC. When used with a range of fluoroscopic units the water phantom was shown to be more diagnostic of image quality performance than copper, using the test protocol. Patient dose rate correlated with image quality results was useful in assessing overall performance