technetium-tc-99m-exametazime and Orbital-Diseases

Bacterial orbital cellulitis is an infection of the soft tissues behind the orbital septum. Cellulitis is seen as a poorly defined area of increased CT density or T2 signal intensity within the fat. There is an amorphous enhancement following contrast infusion. Radiolabeled leukocytes or granulocytes are now established widely as a means of localizing various forms of inflammatory disease and infections. We report a case of orbital cellulitis detected with Tc-99m-HMPAO-labeled WBC scintigraphy and three-phase bone scintigraphy. Tc-99m-HMPAO-labeled WBC scintigraphy was superior to bone scintigraphy in delineating the extension and limits of the infectious process in the orbita. Tc-99m-HMPAO-labeled WBC scintigraphy is appropriate in the investigation of such infectious lesions, leading to early diagnosis and therapy to avoid severe complications.

Topics: Cefotaxime; Cellulitis; Eye Infections, Bacterial; Female; Humans; Leukocytes; Magnetic Resonance Imaging; Metronidazole; Middle Aged; Orbital Diseases; Radionuclide Imaging; Radiopharmaceuticals; Technetium Tc 99m Exametazime; Tomography, X-Ray Computed

Orbital implant infection is a rare cause of anophthalmic socket pain. Because of the potential danger of infection spreading to nearby structures, it is of paramount importance to diagnose the condition as soon as possible. Scintigraphy is a method for diagnosis of graft infections by radioisotopic imaging of inflammatory sites. We report on a patient with socket pain 3 months after implantation of an acrylic implant. The socket appearance was normal and there were no signs of infection other than culture-positive socket exudation. Three consecutive computed tomography scans revealed no abnormalities. 99mTc leukocyte scintigraphy revealed white blood cell accumulation at the implantation site. The implant was removed and cultured. This produced Staphylococcus epidermidis and R. equii. A parenteral antibiotic treatment was instituted with subsequent improvement of symptoms. Four months later, after negative scintigraphy, a hydroxyapatite implant was inserted, demonstrating full vascularization on a bone scan after 2 months. Two months later, the patient developed the previous symptoms, with all of the former findings, including positive scintigraphy. The implant was removed, revealing a microabscess on the anterior aspect, producing S. epidermidis on culture. We conclude that scintigraphy using 99mTc-labeled leukocytes is a useful technique in diagnosing low-grade orbital infection.

Topics: Acrylic Resins; Actinomycetales Infections; Anti-Bacterial Agents; Drug Therapy, Combination; Eye Infections, Bacterial; Female; Follow-Up Studies; Humans; Leukocytes; Middle Aged; Orbital Diseases; Prostheses and Implants; Prosthesis-Related Infections; Radionuclide Imaging; Radiopharmaceuticals; Reoperation; Rhodococcus equi; Staphylococcal Infections; Staphylococcus epidermidis; Technetium Tc 99m Exametazime