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Osteomyelitis of the foot is a well-known complication of diabetes mellitus. In this study, the validity of 111In-labeled human nonspecific immunoglobulin G (IgG) scintigraphy was studied in 16 diabetic patients with foot ulcers, gangrene or painful Charcot joints. In all patients, plain radiographs, conventional bone scan images and 111In-IgG images were recorded. The results were verified by histologic examination of surgical specimens in patients who did not respond to antibiotic treatment within 2-3 wk (10 lesions) or long-term clinical follow-up of at least 6-mo (16 lesions). On the bone scans, all seven osteomyelitic foci were detected. However, 19 additional foci not due to osteomyelitis were seen. The absence of true-negative bone scans in this study resulted in a specificity of 0%. On the plain radiographs, four of seven osteomyelitis foci were detected; for 111In-IgG scintigraphy, six of seven (sensitivity 57% and 86%, respectively). Plain radiographs correctly ruled out osteomyelitis in 15 of 19 lesions, 111In-IgG scintigraphy in 16 of 19 (specificity 79% and 84%, respectively). All imaging procedures gave false-positive results in penetrating ulcers over the calcaneus in two patients and in one patient with a Charcot joint, most likely due to recent fractures. A false-negative 111In-IgG study was observed in a patient with severe arterial angiopathy. Accurate estimation of probable osteomyelitis was not possible from the results of soft-tissue cultures, since in only 6 of 12 positive cultures, osteomyelitic foci could be proven. Indium-111-IgG scintigraphy can contribute to adequate evaluation of osteomyelitis in diabetic foot complications because it improves specificity when compared to bone scan and radiographic findings and improves sensitivity in comparison to plain radiographs.

Indium-111-labeled human nonspecific immunoglobulin G (111In-IgG) is a newly developed radiopharmaceutical for imaging infectious and inflammatory foci. This article presents an overview of the literature concerning 111In-IgG scintigraphy. The current theory about the mechanism of accumulation suggests that 111In-IgG accumulates in lesions as a result of enhanced vascular permeability and subsequent entrapment of the radiolabeled protein. Human studies show excellent results in imaging bone and joint, abdominal, and intravascular infection. Of special interest is the ability to depict infectious foci in granulocytopenic patients. The value of 111In-IgG scintigraphy for detection of infection is compared with that of gallium-67, labeled-leukocyte, and technetium-99m (99mTc) nanocolloid scintigraphy. The significance of differences between 111In-IgG scintigraphy and two other new scintigraphic techniques, 99mTc-labeled IgG and 99mTc-labeled murine monoclonal anti-granulocyte antibody BW 250/183, are discussed.

In 35 patients suspected of an infectious focus, the outcome of scintigraphy with 111In-labeled autologous leukocytes (WBC) and 111In-labeled human nonspecific immunoglobulin G (IgG) was evaluated in a prospective comparative study. Clinical, roentgenologic and microbiologic findings were considered to be proof of the presence of infection or inflammation. In this group of patients with mainly subacute infections, 111In-IgG scintigraphy performed significantly better than 111In-WBC scintigraphy, especially in infections of the locomotor system, but also in various soft-tissue infections. Both techniques showed disappointing results in patients with disseminated yersinia infection and in some patients with tuberculosis. Overall sensitivity and specificity was 74% and 100% for 111In-IgG scintigraphy and 52% and 78% for 111In-WBC scintigraphy, respectively.

This report describes the diagnostic contribution of gallium-67 scintigraphy in 145 cases of fever of unknown origin (FUO) at University Hospital in Leuven, Belgium, in 1980–1989. A final diagnosis was established in 99 (68%) of the 145 cases. Sixty-three scans (43%) were normal, and 82 (57%) were abnormal; only 42 of the abnormal scans (29% of the total number of scans) were considered helpful in diagnosis. Thus 49% of the abnormal scans were considered noncontributory to the diagnosis. In the same population, 15 (6%) of 266 ultrasonograms and 32 (14%) of 233 computed tomograms were helpful in diagnosis. We conclude that gallium scintigraphy remains a valuable screening tool in the investigation of FUO: it yielded diagnostic information in 29% of cases in which the probability of a definitive diagnosis was only 68%. We suggest the use of gallium scintigraphy as a second-step (as opposed to a last-resort) procedure in the evaluation of FUO. [ABSTRACT FROM PUBLISHER]

Nuclear medicine techniques like 99mTc-Leukoscan and 67Ga-citrate scan have been used in localizing infectious pathologies in renal transplant patients. We present an interesting case of febrile renal transplant with discordant findings of tracer uptake in the transplant kidney on 99mTc-Leukoscan and 67Ga-citrate scan. [ABSTRACT FROM AUTHOR]