Scintigraphy, or bone scan, allows a full body assessment of the horses’ bones to image areas which aren’t accessible with an x ray machine. Bone scan detects areas of bone inflammation, or increased bone activity.
Bone scan involves injecting the horse into the bloodstream with an isotope (Technetium 99) and taking images of the horse 2 hours later with a gamma camera. The isotope attaches to bone building blocks and emits a louder signal in areas of high bone turnover (such as in arthritis or fracture repair). These louder signals appear as 'hot spots' when imaged with the gamma camera.
Bone scans are generally used in lameness investigations when the problem is thought to originate in the back, pelvis or upper limbs. Other diagnostic tools such as nerve blocks are not appropriate in these cases.
Horses are booked in for a bone scan in advance, at the request of the vet who has been examining the horse. The horse will need to arrive the afternoon before the procedure to ensure that it is on site and ready for when the isotope is delivered, and will need to stay for a minimum of 48 hours after the procedure until the radioactive isotope has decayed.