Nuclear scintigraphy (bone scanning) is an established and invaluable diagnostic tool used mainly for equine lameness investigations and poor performance evaluations.
Nuclear scintigraphy provides useful complementary information to other imaging techniques (eg. radiography, ultrasonography and magnetic resonance imaging) that can help the veterinary surgeon reach a diagnosis.
Bone scanning involves the intravenous injection of a labelled radioisotope (Technetium 99m MDP) 2 to 3 hours before scanning. The radioisotope is distributed around the horse’s body in the bloodstream and taken up by the soft tissues and bone. The amount of radioisotope taken up at any particular site depends on a number of factors including time after injection, the blood supply to the area and the rate of bone turnover. Areas of damaged or injured bone (eg. fracture, subchondral bone trauma) or areas of inflammation or injury usually result in an increased amount of radioisotope being taken up in that area.
Scintigraphic scans of the skeleton are acquired using a gamma camera which detects gamma rays emitted from the radioisotope .This enables a picture of the radiation in the horse’s body to be produced and “hot spots” or areas of increased uptake of radioisotope to be recognised. This is a non-invasive, painless procedure. The horse is usually sedated during the scan as each scan image takes 1-3 minutes to acquire, during which time the horse needs to stand completely still. As many as 40 scans may be necessary to image the entire horse.
Although this is a safe and useful diagnostic procedure, the technique involves the use of ionising radiation and therefore strict radiation protection regulations are applied to protect attending personnel. For this reason horses must stay at the hospital for 48 hours after injection of radioisotope and during this time strict guidelines must be followed by personnel attending the horse or its stable.
A new state-of-the-art gamma camera was installed at The Liphook Equine Hospital in 2011 and together with new sophisticated software allows us to produce excellent quality scans.
Other scintigraphic evaluations can also be performed at The Liphook Equine Hospital to assess other parts of the horse’s body including scans to evaluate the soft tissues, vasculature, lungs or to detect sites of infection.