A physical comparison of a fluoroscopic CAT system and the EMI head scanner

A quantitative comparison of the capabilities to produce computerized tomograms was made between the EMI head scanner and reconstructions from images provided by a large screen low light level-TV camera fluoroscopic system. A phantom made from lucite containing rods of various materials and sizes was used. The computer printout of each was analyzed and a correlation of 0.8 was noted between the results of both systems. The differential attenuation detectability of the fluoroscopic system was found to be comparable to or better than the EMI unit. As expected from a consideration of the quantum statistics for each system, the noise in the obtained reconstructions was also comparable. It is concluded that such a fluoroscopic system performs favorably when compared to the presently available commercial systems.