The role of technetium-99m-HR HMPAO-labeled WBC scintigraphy in the diagnosis of orbital cellulitis

Bacterial orbital cellulitis is an infection of the soft tissues behind the orbital septum. Cellulitis is seen as a poorly defined area of increased C T density or T2 signal intensity within the fat. There is an amorphous enha ncement following contrast infusion. Radiolabeled leukocytes or granulocyte s are now established widely as a means of localizing various forms of infl ammatory disease and infections. We report a case of orbital cellulitis det ected with Tc-99m-HMPAO-labeled WBC scintigraphy and three-phase bone scint igraphy. Tc-99m-HMPAO-labeled WBC scintigraphy was superior to bone scintig raphy in delineating the extension and limits of the infectious process in the orbita. Tc-99m-HMPAO-labeled WBC scintigraphy is appropriate in the inv estigation of such infectious lesions, leading to early diagnosis and thera py to avoid severe complications.