technetium-tc-99m-exametazime and Infections

This article provides a brief overview of the current state of hybrid single-photon emission computed tomography/computer tomography (SPECT/CT) imaging in musculoskeletal infections. SPECT/CT imaging, compared with conventional planar study and SPECT alone, provides improved anatomic localization of infection and more accurate delineation of the extent of infection. This article emphasizes three clinical aspects where SPECT/CT is found to be most useful: differentiating between soft tissue and bone infections, assessing suspected infected sites with underlying structural bone alterations, and defining infective focus when complex anatomy is involved. The accurate assessment of site of infection is vital for selecting the most appropriate therapeutic strategy. Other advantages of SPECT/CT imaging such as reducing the inconvenience of combination planar studies, providing additional CT information, and increasing interobserver agreement are also discussed.

Topics: Bone Diseases; Child; Foot Diseases; Gallium Radioisotopes; Humans; Indium Radioisotopes; Infections; Musculoskeletal Diseases; Postoperative Complications; Soft Tissue Infections; Spinal Diseases; Technetium Tc 99m Exametazime; Technetium Tc 99m Medronate; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed; Wounds and Injuries

Topics: Fluorodeoxyglucose F18; Gallium Radioisotopes; Humans; Infections; Leukocytes; Nuclear Medicine; Positron-Emission Tomography; Radiopharmaceuticals; Technetium Tc 99m Exametazime; Tomography, Emission-Computed; Tomography, X-Ray Computed

With a current annual mortality rate of around 35% worldwide, infection remains a significant concern, and the diagnosis and localization of infectious foci is an important health issue. As an established infection-imaging modality, nuclear medicine plays a vital health-care role in the diagnosis and subsequent effective treatment of this condition. Despite the development of several newer radiopharmaceuticals, (67)Ga and leukocyte imaging procedures have maintained their established place for infection. Several techniques in nuclear medicine significantly aid infection diagnosis, including imaging with (111)In-oxine-, (99m)Tc-hexamethylpropyleneamine oxime-, and (99m)Tc-stannous fluoride colloid-labeled leukocytes and with (67)Ga-citrate. Each radiopharmaceutical has specific advantages and disadvantages that make it suitable to diagnose different infectious processes (e.g., soft-tissue sepsis, inflammatory bowel disease, osteomyelitis, occult fever, fever of unknown origin, and infections commonly found in immunocompromised patients). After finishing this article, the reader should be able to identify the properties of an ideal radiopharmaceutical for infection imaging, list a range of available infection-imaging radiopharmaceuticals, compare the relative results of a range of radiopharmaceuticals used internationally to detect infection in the body, understand several common infectious processes that can be diagnosed using nuclear medicine techniques, and select an appropriate radiopharmaceutical to image a range of infectious processes.

Topics: Citrates; Fever of Unknown Origin; Gallium; Humans; Infections; Irritable Bowel Syndrome; Leukocytes; Nuclear Medicine; Organometallic Compounds; Osteomyelitis; Oxyquinoline; Practice Patterns, Physicians'; Predictive Value of Tests; Radiopharmaceuticals; Reproducibility of Results; Sensitivity and Specificity; Sepsis; Technetium Compounds; Technetium Tc 99m Exametazime; Tin Fluorides; Tomography, Emission-Computed

Investigators have used various techniques and radionuclides such as 51Cr and 32P-diisofluorophosphate to label blood cells and to study cell survival. Early studies also used these radionuclides to label human leucocytes for cell survival by in-vitro counting. But external imaging could not be done with these agents. Starting with the use of the gamma-emitting radionuclide (111)In-oxine for in-vitro labelling of phagocytic leucocytes, external imaging became possible. This method was the basis of visualisation of cell distribution within the body. Because an abscess consists primarily of leucocytes, leucocytes labelled with (111)In localise within the abscess and are detectable by imaging. Nowadays other radiopharmaceuticals with other underlying uptake mechanisms are also used to detect inflammatory or infectious foci in patients. Nuclear medicine can be most useful in patients with fever of unknown origin, where a focus has to be defined, or in patients where a lesion is known by clinical symptoms or by a radiological imaging and the differentiation between infection and other pathologies has to be made.

Topics: Fever of Unknown Origin; Fluorine Radioisotopes; Gallium Radioisotopes; Humans; Indium Radioisotopes; Infections; Inflammation; Leukocytes; Nuclear Medicine; Organometallic Compounds; Oxyquinoline; Radioimmunodetection; Radiopharmaceuticals; Technetium Tc 99m Exametazime

The spectrum of infectious diseases has changed over the last few years, hence the requirements for radionuclide imaging for the detection of infection are becoming more demanding so that, although gallium-67 and labelled leucocytes remain useful agents, there is currently great interest in the development of new agents especially able to target chronic, non-pyogenic inflammation. Agents can be classified according to the site at which the radiolabel is targeted: pre-endothelial (for example, labelled leucocytes), endothelial (for example, labelled anti-endothelial monoclonal antibodies) or post-endothelial (for example, fluorine-18-fluorodeoxyglucose (FDG)). 67Ga and labelled polyclonal human immunoglobulin (HIG) localize at inflammation initially as a result of increased endothelial permeability, followed by retention of the label through binding to local extravascular receptors. Labelled leucocytes are avidly taken up by acute pyogenic inflammatory foci but perform less well in chronic inflammation. Other indications for labelled leucocytes include bone infection and undiagnosed fever. Nevertheless, since many causes of the latter do not stimulate a neutrophilic infiltrate, a non-specific agent, such as 67Ga, FDG or HIG, may be preferable, especially in patients with no immediate significant medical history. Since endothelial E-selectin expression is closely correlated to lymphocyte migration, labelled anti-E-selectin monoclonal antibody may also have a potential role for imaging chronic inflammation.

Topics: Biomarkers; Fever of Unknown Origin; Fluorodeoxyglucose F18; Gallium Radioisotopes; Humans; Infections; Inflammation; Radionuclide Imaging; Radiopharmaceuticals; Technetium Tc 99m Exametazime

111In or 99mTc-HMPAO labeled leukocyte scintigraphy has been shown to be useful in detection and diagnosis of infections and inflammatory lesions. Results from multiple retrospective series indicate that leukocyte scintigraphy achieves sensitivity and specificity of near 90% in abdominal abscess detection. 99mTc-HMPAO labeled leukocyte scintigraphy is now an accepted technique in the assessment of patients with inflammatory bowel disease and the diagnostic value of early 99mTc-HMPAO labeled leukocyte images has been discussed. It is known that 99mTc-HMPAO labeled leukocytes migrate to a large extent to the bone marrow. 99mTc-HMPAO labeled leukocytes may prove to be a practical agent for bone marrow imaging. In this report, definition, classification and pathological consideration of inflammation, and history, diagnostic efficacy and consideration for clinical application of inflammation scintigraphy are reviewed.

Topics: Bone Marrow Diseases; Contrast Media; Humans; Indium; Infections; Inflammation; Isotope Labeling; Leukocytes; Organotechnetium Compounds; Oximes; Radionuclide Imaging; Sensitivity and Specificity; Technetium Tc 99m Exametazime

Topics: Animals; Horse Diseases; Horses; Infections; Inflammation; Leukocytes; Organotechnetium Compounds; Oximes; Radionuclide Imaging; Technetium Tc 99m Exametazime

Topics: Animals; Chemotactic Factors; Humans; Indium Radioisotopes; Infections; Leukocytes; Liposomes; Organotechnetium Compounds; Oximes; Radioimmunodetection; Technetium Tc 99m Aggregated Albumin; Technetium Tc 99m Exametazime

Topics: Antibodies, Monoclonal; Citrates; Citric Acid; Gallium Radioisotopes; Humans; Indium Radioisotopes; Infections; Inflammation; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

A great deal of effort has been made to evaluate and define the role of various diagnostic imaging techniques in various clinical settings that complicate the diagnosis of osteomyelitis. Except possibly in neonates, bone scintigraphy remains generally recommended when there has been no previous osseous involvement. In other cases of chronic disease, previous fracture or trauma, prosthesis, and diabetic foot, In-WBC scintigraphy is generally accepted as an appropriate imaging technique. MRI will play an increasingly important role in diagnosing osteomyelitis and may prove to be an important adjunct in these cases. Research continues to improve our current diagnostic armamentarium. In-IgG appears to avoid practical deficiencies encountered with 67Ga and In-WBC; it remains to be seen what role this agent will play in routine clinical practice. All agents to date image inflammation, not infection, and most require delayed imaging sessions, usually at 24 hours. These shortcomings necessitate further research to develop new radiotracers that can provide useful images within several hours and that are specific for infection, perhaps ultimately delineating the particular microorganism involved.

Topics: Adult; Bone Diseases; Child; Chronic Disease; Gallium Radioisotopes; Humans; Immunoglobulin G; Indium Radioisotopes; Infant, Newborn; Infections; Magnetic Resonance Imaging; Muscular Diseases; Organotechnetium Compounds; Oximes; Recurrence; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed

The aim of this study was to determine the normal planar and SPET patterns of the thoracic distribution of 99Tcm-hexamethylpropylene amine oxime (99Tcm-HMPAO) in 20 patients who had undergone a previous median sternotomy and without infectious complications at follow-up. The study included anterior and oblique anterior planar views at 4 and 20 h. SPET of the chest was also carried out at 4 and 20 h. At 4 h, the planar views showed low background vascular activity in the lungs and cardiac region in addition to the sternal uptake, which showed two patterns: homogeneous in five patients and heterogeneous in 15. A long and narrow defect of uptake along the sternal midline was the most characteristic finding. At 4 h, in addition to the background vascular activity in the lungs and cardiac region, the greatest uptake on SPET was in the sternum anteriorly and the marrow spine posteriorly without any focal uptake, allowing visualization of the mediastinum free of focal activity. At 20 h, both the planar and SPET images showed a higher organ-to-background ratio. Knowledge of these post-surgical patterns will make it easier to interpret planar and SPET images when 99Tcm-HMPAO-labelled leukocytes are used in the diagnosis of mediastinitis and sternal infections in patients who had previously undergone median sternotomy. Planar views were better for the assessment of sternal uptake, but SPET views were better for the direct visualization of the mediastinum by eliminating overlapping sternal uptake.

Topics: Adult; Aged; Aged, 80 and over; Female; Humans; Infections; Leukocytes; Male; Mediastinal Diseases; Middle Aged; Radiopharmaceuticals; Reference Values; Sternum; Technetium Tc 99m Exametazime; Thoracic Surgical Procedures; Tomography, Emission-Computed, Single-Photon

Leucocytes scintigraphy (LS) is an in-vivo imaging technique investigating infectious foci, performed in our nuclear medicine department after a 99mTc-bisphophonates bone scintigraphy (BS) or an 18F-FDG-PET, in osteoarticular or vascular localizations, respectively. The aim of this study was to reassert the relevance of LS in the diagnostic of occult infections and its impact in therapeutic management.. A 45-month retrospective study (2012-2015), including 34 patients, was conducted. Patients who underwent LS were identified and classified according to the location of the suspected infection and the feature of first-line imaging exploration. The final diagnosis (infected or non-infected lesion) was established regarding patients' follow-up care, including clinical, biological biomarkers and therapeutic interventions. Sensitivity and specificity were calculated for each imaging modality.. LS were conducted for exploration of joint prosthesis (N.=14), vascular prosthesis (N.=7), bone infection or osteitis (N.=8), algoneurodystrophia (N.=2), symphisis infection (N.=1), acute infection on chronicle inflammation (N.=1), and cancer (N.=1). All patients underwent a previous imaging exploration: BS (N.=20, 59%), 18FDG-PET (N.=10, 29%), or another exploration (N.=4, 12%). The sensitivity and specificity of BS were 67% and 36%, respectively, and 100% and 50% for 18FDG-PET, evidencing the lack of specificity of these approaches. Fourteen LS were positive (41%), with sensitivity, specificity and diagnostic accuracy of 85%, 86% and 85%, respectively.. Despite a long, delicate, and costly radiopharmaceutical and nuclear imaging process, the high specificity of LS supports its qualitative added value in the diagnosis of infectious foci, by improving clinical and therapeutic patient's outcomes.

Topics: Cohort Studies; Female; Humans; Infections; Isotope Labeling; Leukocytes; Male; Radionuclide Imaging; Retrospective Studies; Technetium Tc 99m Exametazime

Labeled leukocytes with 99mTc-HMPAO are routinely used for infection imaging. Although cell labeling with 99mTc-HMPAO represents an imaging probe to detect infection sites, the diagnostic efficiency of the probe is largely influenced by cell manipulation, multidisciplinary interventions (i.e., biologist, technicians) and available technology (i.e., SPECT, SPECT/CT). The aim of the study was to assess in vitro and in vivo accuracy of a comprehensive approach for quality assessment (QA) of all steps of the procedure.. Radiochemical purity (RCP), pH, labeling efficiency (LE) were measured in 320 procedures. White Cell Viability Factor (WVF) was determined in consecutive blood samples. Images (490 studies) were scored using a 5-point scale. Training program was evaluated using a Learning Questionnaire and a score system.. Pre/post-labelling WVF was 0.99% (max value 1%) in all blood samples. LE (mean value 72%) and RCP (>80% until 55 minutes) yielded considerably high values. The vast majority of images were scored as diagnostic by three independent observer (90% with score ≥4).. This method appears highly reproducible and easy to use in clinical routine for leukocyte labeling, especially when standardized training and total QA system are implemented.

Topics: Cell Survival; Chemotaxis, Leukocyte; Education, Pharmacy, Continuing; Humans; Infections; Inflammation; Isotope Labeling; Leukocytes; Quality Assurance, Health Care; Radiopharmaceuticals; Reproducibility of Results; Single Photon Emission Computed Tomography Computed Tomography; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

The clinical performance of the Duke Endocarditis Service criteria to establish the diagnosis of infectious endocarditis (IE) can be improved through functional imaging procedures such as radiolabeled leukocytes ((99m)Tc-hexamethylpropyleneamine oxime [HMPAO]-labeled white blood cells [WBC]).. We assessed the value of (99m)Tc-HMPAO-WBC scintigraphy including SPECT/CT acquisitions in a series of 131 consecutive patients with suspected IE. Patients with permanent cardiac devices were excluded. (99m)Tc-HMPAO-WBC scintigraphy results were correlated with transthoracic or transesophageal echocardiography, blood cultures, and the Duke criteria.. Scintigraphy was true-positive in 46 of 51 and false-negative in 5 of 51 cases (90% sensitivity, 94% negative predictive value, and 100% specificity and positive predictive value). No false-positive results were found, even in patients with early IE evaluated within the first 2 mo from the surgical procedure. In 24 of 51 patients with IE, we also found extracardiac uptake, indicating septic embolism in 21 of 24. Despite the fact that septic embolism was found in 11 of 18 cases of Duke-definite IE, most of the added value from the (99m)Tc-HMPAO-WBC scan for decision making was seen in patients in whom the Duke criteria yielded possible IE. The scan was particularly valuable in patients with negative or difficult-to-interpret echocardiographic findings because it correctly classified 11 of 88 of these patients as having IE. Furthermore, 3 patients were falsely positive at echocardiography but correctly negative at (99m)Tc-HMPAO-WBC scintigraphy: these patients had marantic vegetations.. Our results demonstrate the ability of (99m)Tc-HMPAO-WBC scintigraphy to reduce the rate of misdiagnosed cases of IE when combined with standard diagnostic tests in several situations: when clinical suspicion is high but echocardiographic findings are inconclusive; when there is a need for differential diagnosis between septic and sterile vegetations detected at echocardiography; when echocardiographic, laboratory, and clinical data are contradictory; and when valve involvement (especially of a prosthetic valve) needs to be excluded during febrile episodes, sepsis, or postsurgical infections.

Topics: Electrocardiography; Endocarditis; Female; Humans; Infections; Leukocytes; Male; Middle Aged; Multimodal Imaging; Positron-Emission Tomography; Technetium Tc 99m Exametazime; Tomography, X-Ray Computed

We describe here a protocol for labelling autologous white blood cells with (99m)Tc-HMPAO based on previously published consensus papers and guidelines. This protocol includes quality control and safety procedures and is in accordance with current European Union regulations and International Atomic Energy Agency recommendations.

Topics: Cell Separation; Chemotaxis, Leukocyte; Humans; Infections; Inflammation; Isotope Labeling; Leukocytes; Quality Control; Radiation Protection; Radionuclide Imaging; Radiopharmaceuticals; Technetium Tc 99m Exametazime; Tissue Distribution

99mTc-HMPAO-labeled leukocyte scintigraphy (WBCs) is useful in the diagnosis of vascular graft infection. However, false positives can occur in the early postoperative period. There are no data concerning the usefulness of WBCs in detecting endovascular prosthesis infection during this period. The aim of our study was to assess the reliability of WBCs in the diagnosis of early infection after endovascular prosthesis implantation.. 23 patients treated with endovascular grafts were submitted to preoperative diagnostic screening and to 3 WBCs (1 week before, 1 week after, and 1 month after surgery). After the last WBCs, all patients underwent a 14-month follow-up (range 6-37 months, median 12 months).. Three patients died, at 3, 4 and 5 months after surgery respectively. At the end of the follow-up, the presence of infection was demonstrated in one patient. Of the 70 WBCs performed, 4 gave positive results. No positive scintigraphies were obtained in the preoperative period. A positive scintigraphy was found one week after surgery in a patient who showed lymphorrhage at the site of surgical access. In the same patient, the scintigraphic result returned to normal at 1-month scintigraphy. At 12-month follow-up the patient did not present signs of infection. Three positive scintigraphies were obtained in the same patient. In this patient clinical symptoms of graft infection became evident about 19 months after surgery. WBCs was repeated and showed extension of the infection. The infection was confirmed at surgery.. WBCs do not provide false-positives in the first month after endovascular prosthesis implantation.

Topics: Aged; Aged, 80 and over; Angiography; Aorta; Blood Vessel Prosthesis; Blood Vessel Prosthesis Implantation; Female; Femoral Artery; Follow-Up Studies; Humans; Infections; Leukocyte Count; Leukocytes; Male; Middle Aged; Prosthesis-Related Infections; Radiography, Abdominal; Radionuclide Imaging; Radiopharmaceuticals; Technetium Tc 99m Exametazime; Time Factors; Tomography, X-Ray Computed; Treatment Outcome; Ultrasonography, Doppler, Color

Topics: Agranulocytosis; Animals; Gallium Radioisotopes; Humans; Indium Radioisotopes; Infections; Leukocytes; Rabbits; Radionuclide Imaging; Radiopharmaceuticals; Technetium Tc 99m Exametazime; Transplantation, Autologous; Transplantation, Heterologous

The results of the survey carried out in our country during the present year on the nuclear medicine studies in infectious and inflammatory studies during 1999 are presented. They survey was sent to 89 centers with a nuclear medicine service, 45 of which were publicly owned and 44 of which were privately owned. A total of 32 centers (36%) replied to the survey. 51.1% (23 out of 45) of the public hospitals responded but only a 20.5% (9 out of 44) of the private ones did.A total of 70.92% (4,344) out of the 6,125 explorations were carried out to discard and infectious process and 29.07% (1,781) to discard inflammation. The most frequent indication was to discard infections resulting from bone prostheses (2,099 explorations accounting for 48.31% of the total infectious process), followed by bone infection or osteomyelitis (965 explorations, 22.21% of the total). Within the osteomyelitis cases, acute processes motivated the most frequent requests (60.31% of all osteomyelitis cases). Assessment of the scope and localization of the intestinal inflammatory disease was the most frequent request in the inflammation group. Concerning the radiopharmaceuticals used, 99mTc HMAPO or 111I marked-leukocytes were ranked first, these accounting for 47% of the cases. Gallium, used in 44% of all cases, was the second most frequently used, even though it continues to be the more commonly used radiopharmaceuticals for infectious processes.

Topics: Antibodies, Monoclonal; Antibodies, Monoclonal, Murine-Derived; Drug Utilization; Fever of Unknown Origin; Gallium Radioisotopes; Health Care Surveys; Hospitals, Public; Humans; Infections; Inflammation; Intestinal Diseases; Iodine Radioisotopes; Leukocytes; Nuclear Medicine; Osteomyelitis; Prosthesis-Related Infections; Radionuclide Imaging; Radiopharmaceuticals; Spain; Technetium Tc 99m Exametazime

Liposomes encapsulating both glutathione and deferoxamine were labeled with 99mTc-HMPAO and 111In-oxine at the same time. These dual radiolabeled liposomes were intravenously injected in rats with S. aureus infection in thigh. The target-to-background ratio (T/BG) increased from 2.9 at 2 h to 4.4 at 8 h in 99mTc images. In 111In images, T/BG of 5.5 at 8 h increased to 10.5 by 48 h. The 24-h spleen uptake of 111In- and 99mTc-liposomes was 24.14%ID and 8.91%ID. In femur, 99mTc-liposomes remained at approximately 10.5%ID, but 111In-liposomes increased from approximately 11%ID at 4 h to approximately 25.5%ID at 24 h. The simultaneous presence of 99mTc and 111In in the liposomes resulted in good early (2-8 h) as well as delayed (24-48 h) images delineating the infection site.

Topics: Animals; Chelating Agents; Deferoxamine; Glutathione; Image Processing, Computer-Assisted; Indium Radioisotopes; Infections; Inflammation; Liposomes; Radionuclide Imaging; Radiopharmaceuticals; Rats; Rats, Sprague-Dawley; Staphylococcal Infections; Technetium Tc 99m Exametazime; Tissue Distribution

Fever of unknown origin is defined as a temperature above 39.0 degrees C together with a white blood cell count > or = 15,000 mm-3, the duration of fever exceeding 2 weeks and a correct diagnosis not being obtained in the first week of hospitalization. In neonates and infants with fever of unknown origin, the localization of the infectious focus is often difficult and unsatisfactory. In this retrospective study, the clinical value of 99Tcm-labelled antigranulocyte antibodies for this group of patients was investigated. Thirty-two immunoscintigrams were performed using 185-259 MBq 99Tcm-labelled antigranulocyte antibodies (BW 250/183) in 30 neonates and infants (21 boys, 9 girls, mean age 29.4 +/- 2 months), who had fever of unknown origin. Immunoscintigraphy was carried out as whole-body images (n = 7) or single planar images (n = 25) 4 h and 24 h post-injection. In children with known cardiac failure, single photon emission tomography of the thorax was performed to diagnose endocarditis (n = 2). For verification, the results of the immunoscintigrams were compared with radiology (conventional radiography = 14, MRI = 5, CT = 3), biopsy (n = 2), blood culture (n = 10) and clinical follow-up after specific therapy. In 11 of 30 children (36%), the diagnosis of an infective focus was possible with immunoscintigraphy. The sensitivity and specificity of diagnosing infective foci was 72% and 95% respectively (n = 11; colitis = 2, infection of the central permanent catheter tip = 2, middle ear infection = 1, spondylitis/discitis = 3, osteomyelitis = 2, umbilical infection = 1). In vertebral body infections, all lesions were photopenic. In 18 children (60%), no infective focus was found on immunoscintigraphy. In this group of children, the main reason (n = 5) for fever of unknown origin was chronic juvenile rheumatoid arthritis. No uptake was seen in two infants with cardiac failure and suspected endocarditis on SPET. In 3 of the 18 patients (17%), localization of an infective focus was not possible with immunoscintigraphy or on other examinations. In these patients, the fever disappeared spontaneously after a few days of antibiotic therapy. In conclusion, we have shown that 99Tcm-anti-NCA-95 scanning is a safe method with a high sensitivity and specificity for detecting infectious foci in neonates and infants with fever of unknown origin. Furthermore, this method is easy to perform, since no withdrawal of blood is necessary.

Topics: Antibodies, Monoclonal; Child, Preschool; Female; Fever of Unknown Origin; Granulocytes; Humans; Indium Radioisotopes; Infant; Infant, Newborn; Infections; Male; Radioimmunodetection; Retrospective Studies; Sensitivity and Specificity; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Topics: Adult; Child, Preschool; Humans; Infections; Inflammation; Leukocytes; Organotechnetium Compounds; Oximes; Radiation Dosage; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

The aim of this study was to investigate the ability of 111In-labelled human polyclonal immunoglobulin G (111In-IgG) to localize bone and joint infections compared with 99Tcm-HMAPO-labelled leukocytes (99Tcm-WBC). Thirty-four patients routinely referred for investigation of bone and joint infections were studied. In all patients, a bone scan using 99Tcm-MDP was initially obtained. Subsequently, 99Tcm-WBC and 111In-IgG were simultaneously injected and images obtained at 30 min, 4 h and 24 h post-injection. Diagnostic accuracy was established by bacteriology of specimens obtained by needle aspiration and/or surgery, other imaging methods and clinical follow-up. The images were read by three experienced observers blinded to any other information; the clinical suspicion of infection and the diagnosis were established when two observers agreed. Infection was confirmed in 11 patients. The 99Tcm-WBC scans gave 8 true-positive, 5 false-positive, 18 true-negative and 3 false-negative results. With 111In-IgG, the figures were 7, 6, 17 and 4, respectively. The sensitivity, specificity and accuracy were 72.7%, 78.2% and 76.4% respectively for the labelled leukocytes and 63.6%, 73.9% and 70.6% respectively for 111In-IgG. There was greater agreement between the observers with 99Tcm-WBC than 111In-IgG. In this study, 111In-IgG was less sensitive and less specific than 99Tcm-WBC scintigraphy for the diagnosis of chronic infections, but these differences were not significant. Both tracers appear to be useful in the diagnosis of bone and joint infections. However, our results were less reliable for the diagnosis of an infected prosthesis.

Topics: Adult; Aged; Aged, 80 and over; Bone Diseases; Chronic Disease; Diagnostic Errors; Female; Hip Prosthesis; Humans; Immunoglobulin G; Indium Radioisotopes; Infections; Joint Diseases; Knee Prosthesis; Leukocytes; Male; Middle Aged; Organotechnetium Compounds; Oximes; Radioimmunodetection; Technetium Tc 99m Exametazime

Radiolabelled white cell scanning is widely used to detect the presence of infection. We present a case of non-Hodgkin s lymphoma manifesting with signs and symptoms suggestive of infection, in which a technetium-99m hexamethylpropylene amine oxime (99mTc-HMPAO) white cell scan demonstrated high uptake in lymph nodes involved by lymphoma. Differential cell analysis showed preferential lymphocyte labelling. The classification and management of the disease were changed accordingly. Our findings suggest that a future role for 99mTc-HMPAO labelled white cells in the assessment of disease activity of lymphoma should be investigated.

Topics: Diagnosis, Differential; Humans; Infections; Leukocytes; Lymph Nodes; Lymphoma, Non-Hodgkin; Male; Middle Aged; Organotechnetium Compounds; Oximes; Radionuclide Imaging; Technetium Tc 99m Exametazime

Technetium-99m hexamethylpropylene amine oxime (HMPAO)-labeled leukocytes are well established for the investigation of inflammatory disease. Their kinetics and normal distribution are similar to those of indium-111-labeled leukocytes except for nonspecific activity in urine, kidneys, gall bladder, and bowel, which results from the elution of secondary 99mTc-labeled HMPAO complexes. The principal clinical indications for [99mTc]HMPAO-leukocytes include inflammatory bowel disease (IBD), osteomyelitis, soft tissue sepsis, and, to a lesser extent, occult fever. The superior resolution and count density of 99mTc places [99mTc]HMPAO-leukocytes at an advantage over 111In-leukocytes in IBD, especially for the identification of small bowel involvement in patients with Crohn's disease. However, quantification of disease activity is more difficult than with 111In. Technetium-99m HMPAO-leukocytes are indicated for most forms of acute soft tissue and abdominal sepsis, although when compared with 111In, it may be more difficult to demonstrate communication between an abdominal abscess and bowel lumen. Chronic osteomyelitis, including infected joint prostheses, are better approached with 111In-labeled leukocytes. Occult fever and fever of unknown origin (FUO) are more controversial. There is still a place for gallium-67 in FUO, of which there is a wide spectrum of causes. Occult fever implies a pyogenic cause for an undiagnosed fever and should probably be imaged with 111In-leukocytes. With the advances being made in other imaging modalities and in interventional radiology, there is a clear need for radionuclide agents that can be used for whole-body screening in patients with undiagnosed fever. Such agents may include fluorine-18-fluorodeoxy-glucose and radiolabeled monoclonal antibodies to endothelial adhesion molecules activated at the foci of inflammation.

Topics: Bone and Bones; Digestive System; Fever of Unknown Origin; Humans; Infections; Inflammatory Bowel Diseases; Leukocytes; Organotechnetium Compounds; Osteomyelitis; Oximes; Radionuclide Imaging; Technetium Tc 99m Exametazime; Thoracic Diseases

Indium-111 (111In)-labeled leukocyte scanning has been used frequently in patients suspected of having infections. Recently, technetium-99m hexamethylpropylene amine oxime (99mTc-HMPAO) has been used to label leukocytes. This study was undertaken to determine the distribution and dosimetry of 99mTc-HMPAO leukocytes in healthy subjects.. Five healthy volunteers had leukocytes labeled with 99mTc-HMPAO. After injection of the labeled leukocytes, whole body images and blood and urine samples were obtained at multiple time points.. Visual interpretation of the images demonstrated significant bowel activity as early as 2 hours and increasing with time such that one the 8- and 24-hour images, the amount of bowel activity would preclude using 99mTc-HMPAO leukocyte scanning for abdominal processes. The dosimetry for this study is similar to that of other studies and is in an acceptable diagnostic range.. 99mTc-HMPAO leukocyte studies are an acceptable alternative to 111In-labeled leukocyte studies in terms of dosimetry. Use of such studies in the abdomen should be limited to early images, usually before 2 hours, to avoid confusion with the normal route of excretion in the bowel.

Topics: Female; Humans; Infections; Leukocytes; Male; Middle Aged; Organotechnetium Compounds; Oximes; Radiation Dosage; Radiation Protection; Radionuclide Imaging; Reference Values; Technetium Tc 99m Exametazime; Time Factors; Tissue Distribution

Imaging of osteomyelitis and soft-tissue infections can be problematic with currently available agents; bone scans are often false-positive. Indium-111-oxine and 99mTc-HMPAO white blood cell (WBC) scans require ex vivo handling of blood with potential exposure to infectious agents, and 99mTc-antigranulocyte (IgG1) antibodies need 24 hr for final diagnosis.. We investigated the use of 99mTc-murine anti-granulocyte monoclonal Fab' fragment in 20 patients with suspected osteomyelitis of soft-tissue infections. All patients also had 99mTc bone scans and 111In-oxine or 99mTc-HMPAO white blood cell scans. The final diagnosis was confirmed by culture, biopsy, surgery, follow-up, x-rays, CT or MRI. In vitro studies performed on granulocytes demonstrated no effect on their function when the anti-granulocyte monoclonal antibody fragment was added.. Sensitivity, specificity and diagnostic accuracy to detect infection was 88%, 75% and 80%, respectively. All lesions could be detected as early as 1 hr after injection of the antibody fragment. In comparison, WBC scanning had values of 86%, 78% and 81%, respectively. Some lesions could only be detected 24 hr following the injection of labeled WBCs. LeukoScan had three false-positives and WBC scanning had two false-positives.. Immunoscintigraphy with 99mTc-NCA-90 Fab' fragments offers rapid localization of foci, rapid and simple use, a negligible HAMA response rate, no effect on granulocyte function and an accuracy comparable to WBC scanning.

Topics: Adult; Aged; Aged, 80 and over; Antibodies, Monoclonal; Chemotaxis, Leukocyte; Female; Granulocytes; Humans; Infections; Male; Middle Aged; Nitroblue Tetrazolium; Organotechnetium Compounds; Osteomyelitis; Oximes; Phagocytosis; Radionuclide Imaging; Technetium Tc 99m Exametazime; Tetrazolium Salts; Thiazoles

Topics: Acute Disease; Humans; Infections; Leukocytes; Organotechnetium Compounds; Oximes; Radionuclide Imaging; Technetium Tc 99m Exametazime

Accurate diagnosis is essential for the effective management of suspected bone infection. Current imaging techniques have had limited success and further work is required. Although white cell labelling techniques have been available for many years the radiopharmaceuticals employed have disadvantages, particularly in their availability and suitability for imaging. These problems have been overcome by the use of 99Tcm-HMPAO as an in vitro leukocyte labelling agent. The aims of this study were to assess retrospectively its role and accuracy in imaging orthopaedic infection and to compare the results with three-phase bone imaging. 30 patients with suspected bone infection underwent three-phase methylene diphosphonate (MDP) bone imaging and labelled leukocyte imaging on separate occasions. 16 bone scans were positive for infection, of which 14 were subsequently confirmed, and there were no false negatives. There were no false positive white cell studies and only one infection was not identified. 99Tcm-HMPAO white cell imaging has been shown to be an accurate technique for the diagnosis of bone infection but should be performed only following a positive finding on three-phase bone scanning, since the latter is highly sensitive but significantly less expensive, making it a more appropriate screening procedure.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Bone Diseases; Hip Prosthesis; Humans; Infections; Leukocytes; Middle Aged; Organotechnetium Compounds; Oximes; Postoperative Complications; Predictive Value of Tests; Radionuclide Imaging; Retrospective Studies; Sensitivity and Specificity; Technetium Tc 99m Exametazime

Topics: Abdomen; Humans; Infections; Leukocytes; Organotechnetium Compounds; Oximes; Radionuclide Imaging; Technetium Tc 99m Exametazime; Time Factors

Topics: Aged; Female; Humans; Infections; Knee Prosthesis; Leukocytes; Organotechnetium Compounds; Oximes; Postoperative Complications; Radionuclide Imaging; Technetium Tc 99m Exametazime

Tc-99m HMPAO labeled donor leukocytes were used to image the focus of an hepatic infection in a 32-year-old liver transplant patient. Six hours after the administration of labeled leukocytes, radioactivity accumulation was detected in the liver suggesting an intrahepatic infection focus. Diagnosis of infection was confirmed at surgery.

Topics: Adult; Humans; Infections; Leukocytes; Liver Transplantation; Organotechnetium Compounds; Oximes; Radionuclide Imaging; Technetium Tc 99m Exametazime; Transplantation

Topics: Abdomen; Abscess; Humans; Infections; Inflammation; Leukocytes; Organotechnetium Compounds; Oximes; Radionuclide Imaging; Technetium Tc 99m Exametazime

The utility of 99Tcm-HMPAO leucocytes has been studied in combination with 99Tcm-MDP bone scanning in the diagnosis of bone infection in a series of 50 patients with a clinical suspicion of bone infection. Thirty-three patients were referred to our Service from the Department of Orthopaedic Surgery (Group A) and seventeen from the Infectious Disease Unit (Group B). A total of 52 lesion sites were studied. The leucocyte and bone studies were performed within four days. The leucocyte scan was obtained at 30-60 min and 4-6 h after i.v. injection of 370 +/- 74 MBq of 99Tcm-HMPAO leucocytes. After confirming the scintigraphic findings, the results obtained were: Group A, 12 true positive, 21 true negative and 2 false positive; and in Group B, 5 true positive, 9 true negative and 4 false negative. The overall sensitivity was 80.9% with a specificity of 93.7%. Although the high bone marrow activity seen with 99Tcm-HMPAO leucocytes may reduce sensitivity, very good results were obtained in bone infection. The use of 99Tcm means great progress in the radiolabelling of white blood cells in terms of availability and better image quality. The combination of 99Tcm-HMPAO leucocytes and 99Tcm-MDP can be recommended as one of the most suitable methods for use in the diagnosis of bone infection, especially in patients with previous bone disease.

Topics: Adolescent; Adult; Aged; Bone Diseases; Female; Humans; Infections; Leukocytes; Male; Middle Aged; Organotechnetium Compounds; Oximes; Radionuclide Imaging; Sensitivity and Specificity; Technetium Tc 99m Exametazime; Technetium Tc 99m Medronate

Topics: Adult; Antibodies, Monoclonal; Antigen-Antibody Reactions; Female; Granulocytes; Humans; Indium Radioisotopes; Infections; Inflammatory Bowel Diseases; Male; Middle Aged; Organometallic Compounds; Organotechnetium Compounds; Oximes; Oxyquinoline; Radionuclide Imaging; Technetium Tc 99m Exametazime; Tissue Distribution

Topics: Abdomen; Abscess; Adolescent; Adult; Aged; Aged, 80 and over; Arteriovenous Shunt, Surgical; Child; Evaluation Studies as Topic; False Negative Reactions; False Positive Reactions; Female; Fever of Unknown Origin; Humans; Infections; Male; Middle Aged; Organotechnetium Compounds; Osteitis; Oximes; Radionuclide Imaging; Surgical Wound Infection; Technetium Tc 99m Exametazime

Forty-three patients with suspected benign, inflammatory, or infectious diseases were imaged with [99mTc]HM-PAO-labeled leukocytes and [67Ga]citrate. Technetium-99m leukocytes showed 22 true-positive, no false-positive, 19 true-negative, and two false-negative findings and [67Ga]citrate 23, 7, 12 and 1, respectively. The sensitivity, specificity, and accuracy values with 99mTc leukocytes were 92%, 100%, and 95%, and with [67Ga]citrate 96%, 63%, and 81%. Technetium-99m leukocyte scintigraphy has a promising future in comparison with [67Ga]citrate because of the ready availability of [99mTc]HM-PAO, the good image quality, more rapid results (within few hours), and the lower radiation exposure to the patient with 99mTc leukocytes. The usefulness of 99mTc leukocytes in chronic osteomyelitis needs further evaluation.

Topics: Abdomen; Abscess; Adult; Aged; Blood Vessel Prosthesis; Bone Neoplasms; Citrates; Citric Acid; Female; Hip Prosthesis; Humans; Ilium; Infections; Inflammation; Leukocytes; Lymphoma; Male; Middle Aged; Organometallic Compounds; Oximes; Radionuclide Imaging; Technetium; Technetium Tc 99m Exametazime