Nuclear scintigraphy in horses

Nuclear scintigraphy has been used successfully for various applications in horses in the past 30 years. Many private practices and most veterinary schools have gamma cameras, which are used to image an injected radionuclide in an equine patient. Unique exercise-related demands place specific physiologic stressors on the musculoskeletal system of horses. Horses are often pushed beyond normal physiologic limits because of specific performance stresses; therefore, injury to their musculoskeletal system is common. Skeletal scintigraphy is exceedingly sensitive but relatively nonspecific for determining a definitive etiology. Equine scintigraphy is best suited for detecting acute soft tissue and osseous abnormalities because radiopharmaceutical uptake often precedes radiographic detection. However, scintigraphy can also be used to locate potential areas of abnormal osseous turnover in horses with chronic, vague lameness. This article reviews the basic principles of equine scintigraphy, with an emphasis on bone scintigraphy and the clinical applications of this technique. Vascular-, soft tissue-, and bone-phase acquisition are described along with basic image interpretation. Potential pitfalls in image acquisition and interpretation are discussed.