A three-phase bone scan is a diagnostic imaging technique in which a radioactive isotope is used to locate areas of increased activity within the bone. At Southern California Veterinary Imaging, we use Tc-99 radionuclide, which is linked with a substance that concentrates in areas of increased bone activity (osteoblastic activity).
This test is very sensitive and detects bone activity before changes can be detected on x-rays. While 30-50% of bone loss must be present in order for the changes to be visible on x-rays, bone scans allow for abnormalities to be identified sooner. This gives clients additional information that will help them make the most informed decisions about their pets.
Bone scans can be used to detect a variety of conditions:
Detecting metastasis to bone from a primary bone tumor such as OSA (osteosarcoma), or from a type of cancer (such as a prostate carcinoma) that has a predilection for metastasizing to bone
Can be performed prior to amputation to stage a patient and make sure occult disease is not present elsewhere
Can localize the cause of a lameness that is difficult to diagnose
For this diagnostic scan, patients simply need to be positioned on their side. Bone scans are non-invasive, but require sedation since the patient must be completely still for one to two hours to acquire images of the entire body. Most of our patients will be released the same day as their procedure, but some may require overnight hospitalization. Due to California State Law, a pet cannot be released immediately after their procedure. A “holding period” is required to allow the radioactivity to decay before a patient is released from the hospital.