What exactly is a Three Phase Bone Scan , and why would my doctor order a Three Phase Bone Scan ?
People with diabetes often have Three Phase Bone Scans to differentiate Osteomyelitis and Cellulitis in Diabetic Ulcers on their feet.
A Three Phase Bone Scan is performed to determine if an infection is in a patient's bone versus their soft tissue … osteomyelitis versus cellulitis , respectfully.
Osteomylitis is an infection in the bone that generally requires an extended period of treatment utilizing intravenous antibiotics, and occasionally surgical intervention. Cellulitis, an infection in the soft tissue is also treated with antibiotics. Historically, cellulitis is easier to treat than osteomyelitis.
A Three Phase Bone Scan as the name implies, is performed in three stages or phases.
The Blood Flow Stage – The blood flow stage is performed with the area of interest under a Nuclear Medicine Gamma Camera. For example, a wound on a patients right foot …
Both feet are placed under the gamma camera, so that the normal foot may be compared to the abnormal foot.
With the patient's feet in position under the camera, the patient will receive an injection of a radioactive imaging agent in their vein.
As the injection flows through the arteries of the patient's legs and feet, the information can be captured on the cameras database by the Nuclear Medicine Technologist.
A Nuclear Medicine Doctor will review the Blood Flow when the entire study is completed to determine the uniformity of the blood flow through the legs. The Doctor will determine if there is an increase in blood flow in one leg versus the other, or a lack of blood flow in one leg compared to the other.
This concludes the Blood Flow Stage of the study.
The Blood Pool Phase – the Second Phase of the study is the Blood Pool Phase.
Blood Pool imaging is done approximately ten minutes after the patient receives the injection of the radiotracer.
The Blood Pool phase of the Three Phase Bone Scan, documents an increase in blood collecting in the area of interest by imaging redness and swelling.
The Bone Imaging Phase of the Scan is the final stage of the study and is performed anywhere from three to five hours following the injection of the radiopharmaceutical. On occasion images may be taken beyond the five hour imaging session; however, this is very seldom.
The bone imaging portion of the scan, documents bone damage by way of imaging bone repair.
The radiopharmaceutical that is used for Nuclear Bone Scans has an affinity to new bone growth.
There is more concentration of the radioisotope in areas of bone damage, and new bone growth, and this shows on the bone delay images.
Following the entire study, a doctor trained in Nuclear Medicine will interpret the images acquired in the Nuclear Medicine Three Phase Bone Scan.
A report will be dictated and sent to your ordering physician.