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

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

In the past 7 years, single photon emission computed tomography (SPECT) has evolved from an interesting nuclear medicine technique rarely performed because of technical difficulties into a valuable clinical tool in the management of cancer cases. The development of stable multidetector instruments with collimators and gantries specifically designed for SPECT and the introduction of new radiopharmaceuticals recently approved by the U.S. Food and Drug Administration have rapidly moved SPECT from the field of clinical investigation to clinical practice. SPECT is a valuable addition to other tomographic modalities capable of displaying the physiology of disease as well as anatomy. In this work the authors describe the role of SPECT in a cancer center and, in particular, how they use it to solve clinical problems. They also review the published literature, when appropriate. The authors have found SPECT of particular value in evaluation of myocardial ischemia, in differentiating tumor recurrence from posttherapy changes in the lymphomas, in tumor diagnosis and surveillance, and in separating hemangioma from malignant lesions in the liver.

Topics: Abdomen; Amphetamines; Antibodies, Monoclonal; Bone Diseases; Brain Diseases; Cardiovascular Diseases; Humans; Neoplasms; Organotechnetium Compounds; Oximes; Quality Control; Technetium Tc 99m Exametazime; Thallium Radioisotopes; 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

Topics: Adult; Bone Diseases; Brain Diseases; Echinococcosis; Echinococcosis, Hepatic; Female; Humans; Magnetic Resonance Imaging; Parietal Bone; Radiopharmaceuticals; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed; Ultrasonography

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

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

Bone marrow scintigrams obtained 2-6 h and/or 20-24 h after injection of 99Tcm-HMPAO-labelled leucocytes (LeuSc) in 16 patients (seven males, nine females, average age 57 years, either with benign or malignant haemopathy, or with benign or metastatic skeletal diseases) have been compared to corresponding pictures obtained 20 min after injection of 99Tcm-labelled human serum albumin nanosized colloids (NanSc, performed within a week thereafter). Overall distribution of the colloids and of the labelled leukocytes at the level of the bone marrow appeared to be the same. Fresh vertebral fractures as well as metastatic lesions of the axial skeleton appeared as cold defects in both investigations. Fractures of the ribs as well as one metastatic lesion involving one trochanter could not be identified. Although all seven lesions involving Th9 to L4 could be clearly investigated with LeuSc, only three could be recognized with NanSc. It is concluded that, in patients with cancerous diseases, LeuSc is better than NanSc in demonstrating lesions in the case of dubious conventional osseous scintigrams as well as in the case of neurological or skeletal symptoms at the level of the lumbar and/or low thoracic regions.

Topics: Bone Diseases; Bone Marrow; Bone Neoplasms; Female; Fractures, Bone; Humans; Leukocytes; Male; Middle Aged; Organotechnetium Compounds; Oximes; Radionuclide Imaging; Technetium Tc 99m Aggregated Albumin; 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

The use of labelled granulocyte scintigraphy is recognized as a reliable method for detecting osteomyelitis and other skeletal sepsis. Tc-99m hexamethyl propyleneamine oxime (Tc-99m HM-PAO), a lipophilic chelate offers the advantages of availability, lower radiation dose and higher image resolution, compared to other labelling agents. We have scanned 36 orthopedic patients with suspected infection, using autologous granulocytes labelled with Tc-99m HM-PAO. In all cases, scans were compared with clinical, microbiological and/or surgical findings. Sensitivity was 94% and specificity was 80%. We therefore believe that Tc-99m HM-PAO leucocyte scanning provides a useful method for detecting osteomyelitis and other skeletal infections.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Bone Diseases; Female; Granulocytes; Hip Prosthesis; Humans; Male; Middle Aged; Organotechnetium Compounds; Osteomyelitis; Oximes; Predictive Value of Tests; Radionuclide Imaging; Surgical Wound Infection; Technetium Tc 99m Exametazime