Radionuclides differ in the reliability with which they can be used to detect orbital abnormalities. In our series of 30 patients, positive sodium pertechnetate Tc 99m (TPT) scans were associated with inflammatory, highly vascular, and neoplastic tissues. Chlormerodrin Hg 197 was most frequently taken up by neoplasms. By performing en face scans with both chlormerodrin Hg 197 and TPT lesions can be localized and characterized more accurately than is possible with one tracer or by conventional radiographic methods alone.
Grove AS, Kotner LM. Orbital Scanning With Multiple Radionuclides. Arch Ophthalmol. 1973;89(4):301-305. doi:10.1001/archopht.1973.01000040303009