Thallium-201 uptake in the orbits.

Thallium-201 uptake patterns in the orbits are not widely known. Diffuse, bilateral orbital localization of TI-201 chloride may be an incidental finding because of orbital muscle or other soft tissue uptake. Differences in orbital blood flow and soft tissue mass may be the cause of the varying uptake intensities in most cases. Focal uptakes, even when bilateral, may indicate specific pathology and should be investigated. Sample cases are presented.