technetium-tc-99m-medronate and Wounds-and-Injuries

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

A 2.5-year-old female Thoroughbred horse was referred to the veterinary teaching hospital for right front limb lameness of 1 year duration. Physical examination and diagnostic nerve blocks failed to localize the origin of the lameness. Scintigraphy with 99mTc-MDP suggested increased radionuclide uptake in the palmar metacarpal soft tissues of the right front limb. Ultrasonographic examination revealed hypoechoic lesions in the superficial digital flexor tendon and the suspensory ligament, suggesting tendinitis and desmitis. Combined imaging modalities improved detection and characterization of the cause of a long-standing obscure lameness.

Topics: Animals; Female; Forelimb; Horse Diseases; Horses; Metacarpus; Movement Disorders; Radiography; Radionuclide Imaging; Technetium Tc 99m Medronate; Ultrasonography; Wounds and Injuries

We studied the results of bone scans in 50 consecutive patients with symptomatic, unilateral, chronic anterior cruciate ligament (ACL) tears. All patients had failed conservative therapy and underwent radionuclide imaging of the knee prior to arthroscopic ACL reconstruction. The scintigraphic activity in each of the three knee compartments was quantitatively scaled from 1 (normal scintigraphic activity) to 4 (marked activity). Quantitative activity in each of the three compartments was correlated with plain radiographic, arthroscopic, and clinical findings. All but four of the scans (92%) showed abnormal scintigraphic activity. The quantitative activity was highest overall in the medial compartment (2.9), followed by the lateral (2.4) and patellofemoral compartments (1.9). In the subgroup of patients with normal menisci (10 patients), most of the abnormal activity was in the lateral compartment (2.9), implying that when the medial meniscus remains competent in the presence of a torn ACL, there is increased stress on the lateral compartment. There was little correlation with scintigraphy and roentgenographic changes, except in the presence of moderate or severe radiographic degenerative arthritis. Similarly, there was little correlation between increased scintigraphic activity and chondromalacia. These results provide a baseline for future studies that use scintigraphic imaging in monitoring restoration of bone homeostasis following ACL reconstruction.

Topics: Adolescent; Adult; Anterior Cruciate Ligament; Anterior Cruciate Ligament Injuries; Arthroscopy; Cartilage Diseases; Chronic Disease; Evaluation Studies as Topic; Female; Humans; Injury Severity Score; Male; Osteoarthritis; Preoperative Care; Radiography; Radionuclide Imaging; Sensitivity and Specificity; Technetium Tc 99m Medronate; Wounds and Injuries

Scintigraphy with technetium-99m methylene diphosphonate (MDP) delineates a wide spectrum of nonosseous disorders. Neoplastic, hormonal, inflammatory, ischemic, traumatic, excretory, and artifactual entities demonstrate abnormal soft-tissue uptake of Tc-99m MDP. Mechanisms leading to increased extraosseous Tc-99m MDP uptake include extracellular fluid expansion, enhanced regional vascularity and permeability, and elevated tissue calcium concentration. The composition of the calcium deposition and the presence of other metallic ions (eg, iron and magnesium) are important. Soft-tissue Tc-99m MDP uptake is seen in benign (tumoral calcinosis, myositis ossificans) and malignant (sarcomas, adenocarcinomas, metastases) neoplastic entities. Hormonal disturbances in calcium metabolism, especially in hyperparathyroidism, can lead to metastatic calcification, visualized with Tc-99m MDP scintigraphy. Tissue damage from inflammation, infection, or physical trauma results in localized hyperemia, edema, or calcium (and hemosiderin) deposition based on their pathophysiologic characteristics. Urinary tract obstruction, anomalies, or dysfunction are demonstrated by Tc-99m MDP imaging. Common artifacts are related to faulty radiopharmaceutical preparation, Tc-99m MDP administration, and imaging technique. Recognition of these modes of extraskeletal Tc-99m MDP uptake can enhance the diagnostic value of bone scintigraphy.

Topics: Adult; Aged; Artifacts; Bone and Bones; Child; Child, Preschool; Endocrine System Diseases; Female; Humans; Inflammation; Ischemia; Male; Middle Aged; Neoplasms; Radionuclide Imaging; Technetium Tc 99m Medronate; Urologic Diseases; Wounds and Injuries

Topics: Adult; Biopsy; Diagnosis, Differential; Humans; Male; Myositis Ossificans; Soft Tissue Neoplasms; Technetium Tc 99m Medronate; Tomography, X-Ray Computed; Wounds and Injuries