Nuclear Scintigraphy (Bone Scanning)
Nuclear scintigraphy is an important diagnostic aid for the examination of lame or poorly performing horses and is useful in cases where:
- An area of lameness has been localised with the use of nerve blocks but there have been no abnormalities detected on radiography or ultrasonography of the area
- Nerve blocks have not revealed the cause of lameness
- There is multi-limb lameness
- An area cannot be easily penetrated by X-ray (e.g. the pelvis)
Ideally, we normally assess the horse the day prior to the scan. However, if a scan is to be performed the same day as the appointment date, the horse must be at the Diagnostic Centre no later than 9am.
A labelled radioactive isotope (technetium 99) is injected into the horse a few hours before the scan is performed to allow sufficient uptake into the bone, where it becomes attached, thus mapping out the skeletal system. Using a gamma camera, the scan will pick up areas of increased bone metabolism as the isotope attaches itself in increased amounts to areas which are undergoing remodelling processes and is a good way of assessing the back, pelvis and upper limbs of the horse. It is particularly useful for identifying stress fractures, which may not be detected on radiographic examination, and for monitoring fracture healing.
Although it is a safe procedure, nuclear scintigraphy examinations are only undertaken when there is a specific indication to do so. In order to satisfy the Radiation Regulations for exposure to the public, we retain the horse under controlled conditions until the radioactive isotope is sufficiently decayed. The horse is unable to leave the hospital until 4pm the following day and visiting is also restricted until this time.
