Gallium-67/technetium-99m methylene diphosphonate ratio imaging: early rabbit osteomyelitis and fracture.

Simultaneous digital acquisition of [67Ga] and [99mTc]MDP images, and subsequent division of the first by the second to produce a parametric ratio image (G/T), is employed to characterize the relative localization of the two radiopharmaceuticals in early rabbit tibia Staphloccocus aureus osteomyelitis and fracture repair. Images obtained during the first 48 hr of each condition show preferential 67Ga accumulation probably reflecting an initial inflammatory response while G/T images at 5-7 days show predominance of the bone-seeking scan agent, which may indicate that the dominant process is osteoblastic repair.