Nuclear scintigraphy (a.k.a. bone scans or nuke scans) is a diagnostic tool that can be used to help localize issues such as orthopedic concerns like fractures, injuries, joint inflammation and osteoarthritis, as well as a variety of other conditions. Nuclear scintigraphy has very high sensitivity to help uncover regions of interest, but only moderate specificity (as compared to other imaging techniques). Its unique value is that it can help us locate the areas most likely to be causing problems, direct more detailed studies using other diagnostic imaging modalities, and/or develop evidence-based treatment plans.
When is a Bone Scan Useful?
Nuclear scintigraphy is a great diagnostic tool for horses who seem to have subtle or "mystery" lameness. This may include a horse for which nerve blocking hasn't successfully indicated the source of lameness, just doesn't feel right under saddle, shows overall poor performance, or has multiple limb lameness. It helps us figure out where there is active inflammation and can often uncover stress fractures that are not apparent on radiographs.
Benefits of Bone Scans
Nuclear scintigraphy can help:
Consider multiple areas within the body at once
Find problems not seen using other imaging modalities
Look at areas that may be difficult to image using other techniques
We have the option to scan the front end of the horse, the hind end, or even the whole body if multiple issues seem to be involved or when the cause has a completely unknown location. Our nuclear scintigraphy machine is able to explore neck, back and pelvic issues, as well as distal limb issues.
General anesthesia is not necessary; nuclear scintigraphy is performed standing, with mild sedation.
Results can be seen the same day.
How it's Done and How it Works
A small, tracer amount of a radioactive isotope called technetium is injected into the horse intravenously. It takes about three hours for this radiotracer to fully penetrate the bone, where it binds to areas of exposed hydroxyappetite (a naturally occurring, bone-forming mineral) and emits gamma rays. We then mildly sedate the horse and use a special gamma camera to detect the radiation. It can take up to four hours to complete a full-body scan. A computer processes the scan, measuring the amount of radiotracer absorbed in different areas, and produces images offering information on both the structure and function of various internal body parts.
Things to Know About Scheduling a Bone Scan
Nuclear scintigraphy is performed at our Menlo Park facility.
Your horse will need to arrive the day before the scan.
Your horse will receive an IV catheter and will be mildly sedated during the procedure.
Your horse will need to stay for two days after the scan while the radioactivity dissipates. During this time, your horse cannot leave the isolation stall or have visitors inside the stall.
After two days of isolation, your horse will no longer be radioactive, and will be ready for any further diagnostics or therapeutics recommended based on bone scan findings.
Bone Scan Client Form and FAQ
This Nuclear Scintigraphy Form and FAQ is a 2-page PDF that includes a form that must be completed and submitted when scheduling a bone scan, which will provide us with pertinent account information, as well as critical information about your horse to ensure we order the right amount of technetium. It also includes answers to frequently asked questions about the procedure.