Equine bone scintigraphic uptake patterns related to age, breed, and occupation

It is well known that skeletal scintigraphy is an imaging modality with high sensitivity but low specificity. Sites of IRU provide good evidence of increased bone turnover but not its specific cause. Results of lameness workups, blocks, and other imaging techniques are required to determine specific causes. Overinterpretation of causes of IRU is tempting, especially in assigning diagnoses to EIBR--adaptive or non-adaptive. Nevertheless, a quarter of a century's experience with equine skeletal scintigraphy has shown that certain patterns and locations can be fairly predictive of certain pathologic findings. It behooves the equine scintigrapher to know those patterns and how they are affected by the patient's age, breed, and occupation so that he or she can indicate how to best focus other diagnostic procedures toward a definitive diagnosis. Those who are conducting research involving equine skeletal scintigraphy are challenged to help sharpen that focus, especially in evaluating the significance of relatively mild IRUs. Equine clinicians who use scintigraphy in their lameness workups are especially challenged. Working in concert with nuclear medicine imagers, they are in the best position to garner, collate, and analyze the information that is needed to correlate IRUs and the clinical picture. As difficult as they are to design and conduct, such studies are most productive if done prospectively and are most rewarding for those who carry them through.