Nuclear scintigraphy, otherwise known as a ‘bone scan’, is a diagnostic procedure that uses a very small amount of radioactive molecules to help diagnose diseases involving bone, soft tissue and blood vessels. Our veterinarians utilize this diagnostic modality in complex or difficult cases where the cause of lameness is not easily identifiable or is originating in multiple different places.

 

The procedure involves injecting a small amount of radioactive isotope into the patient’s vein. These isotope molecules can be attached to different substances that will bind to lesions in bone, soft tissue and sites of inflammation. The circulatory system will carry these molecules throughout the patient’s body, and the molecules will collect wherever there is increased bone turnover or soft tissue inflammation.  A device called a “Gamma camera” is positioned over different portions of the patient’s body – this camera can detect the radioactive energy given off by the isotope. A specialized computer and software system then translates the data received by the gamma camera into an image showing the soft tissue and skeletal structure of the patient. Our veterinarians then interpret these images looking for areas of increased isotope concentration – ‘hot spots’. Once the area of concern has been identified, other diagnostic techniques such as x-ray and ultrasound can be used to further define the underlying disease.

 

Scintigraphy has several advantages in difficult cases, including: 1) It is a much more sensitive indicator of bone damage than x-rays; 2) We can position the gamma camera anywhere on the horse’s body, allowing us to image the back, neck, head, ribs, pelvis and all four limbs easily; 3)We can evaluate areas on the horse that cannot be easily imaged or blocked with routine techniques; 4)Scintigraphy can also be used to evaluate the blood flow to the limbs and soft tissues, allowing us to evaluate for soft tissue injuries at the same time as bone injuries; and 5) We can image the entire horse in a relatively short period of time.

 

Federal radiation regulations require that the patient remain hospitalized for 24 hours after injection of the radioactive material. During this time, the patient will eliminate all of the radioactive material through their urine. Once the patient is no longer considered ‘radioactive’, they are released to go home.

 

Ultimately, nuclear scintigraphy is a very valuable diagnostic tool that can aid veterinarians in diagnosing and treating subtle and complex lamenesses.