Nuclear scintigraphy (sometimes known as "bone scanning") is an invaluable diagnostic tool to help us diagnose the cause of lameness in some patients. It is particularly useful in cases where the horse is under performing and lameness is subtle meaning that nerve blocking is not possible. It is also very useful in cases of multi-limb lameness and in difficult to image areas such as the neck, back and pelvis. It is mainly used for imaging bones, although vascular and soft tissue phases are also possible.
The procedure involves injecting the horse with a radioactive "dye" (technetium 99), which is taken up by areas of abnormally increased bone activity. Shortly after this a special gamma camera is used to detect the radioactivity produced and provide detailed images of the skeleton. It is particularly useful to identify causes of back and neck pain, sacro-iliac disease and inflamed joints where radiographs have not diagnosed the problem.
Although it is well known to be a safe procedure, after injection and imaging the horse is kept in controlled conditions for 2 days to comply with radiation safety regulation requirements. Once this time has elapsed further investigations and treatments may be performed before a horse is discharged from the clinic.