technetium-tc-99m-exametazime and Diabetic-Foot

Diagnosing diabetic foot infection is often difficult, despite several available diagnostic methods. Amongst these, several imaging modalities exist to evaluate the diabetic foot in case of a suspected osteomyelitis. Nuclear Medicine, in particular, offers a variety of radiopharmaceuticals and techniques. Nowadays the gold standard radionuclide procedure, when an osteomyelitis is suspected, is represented by the use of radiolabelled leukocytes with either. In this review, we describe the correct acquisition and interpretation of white blood cell scintigraphy and we provide an overview of the existing literature data of the use of this technique in the infected diabetic foot. If images are correctly acquired, displayed and interpreted, this modality reaches very high diagnostic accuracy (>95%) in detecting osteomyelitis and it allows the differential diagnosis with a soft tissue infection or inflammation. Single-photon emission computed tomography/computed tomography (SPECT/CT) in addition to planar images is mandatory to determine the extent and exact location of the infective process in both fore foot and midhint foot. With the addition of bone marrow scintigraphy using radiolabelled nanocolloids, radiolabelled white blood cell scintigraphy is also able to differentiate between Charcot neuroarthropathy and osteomyelitis, which is a challenge in the evaluation of diabetic foot. Radiolabelled anti-granulocyte monoclonal antibodies and their fragments can also be used instead of white blood cells although there is a limited experience on their usefulness in diabetic foot infection.

Topics: Diabetic Foot; Humans; Leukocytes; Organometallic Compounds; Oxyquinoline; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Topics: Arthropathy, Neurogenic; Diabetic Foot; Diagnostic Imaging; Humans; Magnetic Resonance Imaging; Osteomyelitis; Positron-Emission Tomography; Radiopharmaceuticals; Sensitivity and Specificity; Technetium Tc 99m Exametazime; Technetium Tc 99m Medronate; Tomography, X-Ray Computed

White blood cell (WBC) scintigraphy is considered the nuclear medicine imaging gold standard for diagnosing osteomyelitis in the diabetic foot. Recent papers have suggested that the use of (18)F-FDG PET/CT produces similar diagnostic accuracy, but clear interpretation criteria have not yet been established. Our aim was to evaluate the role of sequential (18)F-FDG PET/CT in patients with a high suspicion of osteomyelitis to define objective interpretation criteria to be compared with WBC scintigraphy.. Thirteen patients whom clinicians considered positive for osteomyelitis (7 with ulcers, 6 with exposed bone) were enrolled. The patients underwent (99m)Tc-exametazime WBC scintigraphy with acquisition times of 30 min, 3 h, and 20 h and sequential (18)F-FDG PET/CT with acquisition times of 10 min, 1 h, and 2 h. A biopsy or tissue culture was performed for final diagnosis. Several interpretation criteria (qualitative and quantitative) were tested.. At final biopsy, 7 patients had osteomyelitis, 2 had soft-tissue infection without osteomyelitis, and 4 had no infection. The best interpretation criterion for osteomyelitis with WBC scintigraphy was a target-to-background (T/B) ratio greater than 2.0 at 20 h and increasing with time. A T/B ratio greater than 2.0 at 20 h but stable or decreasing with time was suggestive of soft-tissue infection. A T/B ratio of no more than 2.0 at 20 h excluded an infection. Thus, sensitivity, specificity, positive predictive value, negative predictive value, and accuracy for osteomyelitis were 86%, 100%, 100%, 86%, and 92%, respectively. For (18)F-FDG PET/CT, the best interpretation criterion for osteomyelitis was a maximal standardized uptake value (SUVmax) greater than 2.0 at 1 and 2 h and increasing with time. A SUVmax greater than 2.0 after 1 and 2 h but stable or decreasing with time was suggestive of a soft-tissue infection. An SUVmax less than 2.0 excluded an infection. (18)F-FDG PET at 10 min was not useful. Using these criteria, sensitivity, specificity, positive predictive value, negative predictive value, and accuracy for osteomyelitis were 43%, 67%, 60%, 50%, and 54%, respectively. Combining visual assessment of PET at 1 h and CT was best for differentiating between osteomyelitis and soft-tissue infection, with a diagnostic accuracy of 62%.. (18)F-FDG PET/CT, even with sequential imaging, has a low diagnostic accuracy for osteomyelitis and cannot replace WBC scintigraphy in patients with diabetic foot.

Topics: Aged; Aged, 80 and over; Diabetic Foot; Diagnosis, Differential; Fluorodeoxyglucose F18; Humans; Image Processing, Computer-Assisted; Leukocytes; Male; Middle Aged; Osteomyelitis; Positron-Emission Tomography; Sensitivity and Specificity; Soft Tissue Infections; Technetium Tc 99m Exametazime; Time Factors; Tomography, X-Ray Computed

Our aim was to evaluate the role of SPECT/CT for the diagnosis of diabetic foot infection by labeled leukocytes.. Seventeen patients with 19 clinically suspected sites of infection were included. After leukocyte labeling and administration, planar scans were acquired at 30 min, 4 h, and 24 h for 18 consecutive patients. SPECT/CT was obtained at 6 h. The final diagnosis was established by clinical follow-up (24 mo) in all cases and by bone biopsy for 14 sites.. Leukocyte scanning was positive in 16 of 19 lesions and negative in 3. SPECT/CT changed the interpretation of the planar and SPECT images for 10 of 19 suspected sites (52.6%): it excluded osteomyelitis in 6 cases, revealed bone infection in 1 case, and revealed both bone and soft-tissue infection in 3 cases. The hybrid device did not significantly contribute to the evaluation of patients with negative scan results.. SPECT/CT can be useful for a more accurate diagnosis of diabetic foot infection by labeled leukocyte imaging.

Topics: Diabetic Foot; Female; Humans; Leukocytes; Male; Middle Aged; Radiopharmaceuticals; Reproducibility of Results; Sensitivity and Specificity; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed

Foot infections and their sequelae are among the most common and severe complications of diabetes mellitus. As diabetic patients with foot infections develop osteomyelitis and may progress to amputation, early diagnosis of osteomyelitis is critical.. We compared the diagnostic values of labelled leucocyte scanning with Tc(99)m, magnetic resonance imaging (MRI) and microbiological examination of bone tissue specimens with histopathology, the definitive diagnostic procedure. Thirty-one diabetic patients with foot lesions were enrolled in the study and histopathological examination was performed in all. Patients had clinically suspected foot lesions of > or = grade 3 according to the classification of Wagner.. Bone specimens were obtained for histopathological examination. Microbiology had a sensitivity of 92% and specificity of 60%. Labelled leucocyte scanning had a sensitivity of 91%, specificity of 67%, and MRI a sensitivity of 78%, specificity of 60%.. Microbiological examination may be as useful as and less costly than other diagnostic procedures and is the only method which can guide the choice of antibiotic therapy.

Topics: Adult; Aged; Biopsy; Blood Sedimentation; Bone and Bones; Bone Marrow; C-Reactive Protein; Diabetic Foot; Female; Humans; Isotope Labeling; Leukocyte Count; Leukocytes; Magnetic Resonance Imaging; Male; Middle Aged; Osteomyelitis; Radionuclide Imaging; Radiopharmaceuticals; Sensitivity and Specificity; Technetium Tc 99m Exametazime; Technetium Tc 99m Medronate

The aim of this prospective study was to assess the role of 99mTc-HMPAO leucocyte scintigraphy combined with a 99mTc-MDP bone scintigraphy in the diagnosis of the diabetic foot infection (HMPAO-Leu/MDP).. 75 diabetic patients with suspected osteomyelitis were included. The HMPAO-Leu/MDP scan was considered to be consistent with osteomyelitis when the HMPAO-Leu uptake was concordant in all the incidences with an MDP bone uptake. A HMPAO-Leu uptake without concordant bone MDP activity was considered as a soft-tissue infection. The results of the HMPAO-Leu/MDP scan were compared to the following diagnostic criteria: bone infection was confirmed by radiological follow-up or bone biopsy; the absence of bone infection was confirmed by clinical (healing of the ulcer without antibiotherapy) and radiological follow up.. According to these criteria, among the 83 ulcers, bone infection was observed in 41 (49.4%): the HMPAO-Leu/MDP scan was positive in 38 cases, including 14 ulcers with normal or doubtful radiographs at inclusion. In the group of 42 ulcers without proven bone infection, the HMPAO-Leu/MDP scan was negative in 41 cases, including 17 lesions with a soft-tissue infection.. With a sensitivity of 92.6%, a specificity of 97.6%, the HMPAO-Leu/MDP scan is a reliable tool for the diagnosis of osteomyelitis in the diabetic foot. Neuroarthropathy did not affect the performances of the HMPAO-Leu/MDP scan. Owing to a high spatial resolution this test is very helpful to differentiate bone infection from soft-tissue infection especially in case of neuroarthropathy.

Topics: Adult; Age of Onset; Aged; Aged, 80 and over; Diabetic Foot; Female; Humans; Leukocytes; Male; Middle Aged; Osteomyelitis; Radionuclide Imaging; Radiopharmaceuticals; Reproducibility of Results; Technetium Tc 99m Exametazime; Technetium Tc 99m Medronate

The diagnosis of diabetic foot osteomyelitis is often difficult both clinically and radiologically with a delay in radiological sign occurrence and difficulties of imaging interpretation. Bone biopsy is known to be the diagnosis gold standard. However, if negative, the diagnosis of osteomyelitis cannot be excluded and this method is not harmless. An early diagnosis of osteomyelitis is necessary to start an antibiotic treatment in conjunction with conservative surgery. (99m)Tc-HMPAO labelled leucocyte scintigraphy performed in conjunction with bone scintigraphy significantly contributes to the diagnosis of osteomyelitis (sensitivity=100% and specificity > 95%). In case of osteomyelitis suspicion, after plain radiography, the (99m)Tc-MDP bone scintigraphy is the first step. If negative, osteomyelitis is unlikely. If positive, a (99m)Tc-HMPAO leucocyte scintigraphy should be performed in order to exclude or to confirm the diagnosis of bone infection.

Topics: Diabetic Foot; Humans; Osteomyelitis; Radiography; Radionuclide Imaging; Radiopharmaceuticals; Sensitivity and Specificity; Technetium Tc 99m Exametazime

We conducted a prospective study in order to evaluate the contribution of technetium-99m hexamethylpropylene amine oxime (HMPAO) labelled leucocyte scintigraphy to the diagnosis and follow-up of osteomyelitis in the diabetic foot. The study was conducted between October 1992 and November 1996 and included 42 patients (30 men and 12 women; mean age 63 years) with diabetes mellitus (type 1, n = 22, type 2, n = 20) who had a total of 56 diabetic foot ulcers. The initial exploration included standard radiography, three-phase bone scintigraphy and 99mTc-HMPAO labelled leucocyte scintigraphy (HMPAO-LS), performed within a 3-day interval. For the 56 ulceration sites, 26 cases of osteomyelitis were diagnosed: ten on the basis of radiographic and histological/bacteriological criteria after bone biopsy, 11 after radiographic follow-up and five on the basis of biopsy results alone. No osteomyelitis was present at 30 sites, there were seven cases of cellulitis. The sensitivity and specificity of 99mTc-HMPAO-LS were 88.4% and 96.6% respectively (23 true-positives, 29 true-negatives, one false-positive, three false-negatives). The accuracy of radiography, 99mTc-methylene diphosphonate and HMPAO-LS was 69.6%, 62.5%, and 92.9%, respectively. Follow-up scintigraphy (n = 14) 4 months after initial diagnosis and 1 month after antibiotic withdrawal confirmed cure of osteomyelitis despite the absence of complete clinical regression of the ulcers. In conclusion, 99mTc-HMPAO labelled leucocyte scintigraphy was found to be an excellent method for the diagnosis of osteomyelitis in the diabetic foot. It can contribute to follow-up, particularly when clinical regression of perforating ulcers is incomplete and cure of osteomyelitis must be confirmed in order that antibiotic treatment may be discontinued.

Topics: Adult; Aged; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Diabetic Foot; False Negative Reactions; False Positive Reactions; Female; Humans; Leukocytes; Male; Middle Aged; Osteomyelitis; Prospective Studies; Radiography; Radionuclide Imaging; Radiopharmaceuticals; Technetium Tc 99m Exametazime