SNM's Image of the Year: PET/CT of cervical spine hardware

SNM Image of the Year: F18 NaF PET/CT of Cervical Spine Fixation Hardware. Image Source: SNM

The Society of Nuclear Medicine’s (SNM) 2011 Image of the Year illustrates the ability of PET/CT scans to identify abnormal bone reaction in patients who have received spinal fixation hardware implants. Researchers selected this image from more than 1,800 studies presented over the course of four days during SNM’s 58th annual meeting in San Antonio, Texas.

Each year, SNM chooses an image that exemplifies cutting-edge molecular imaging research and demonstrates the ability of molecular imaging to detect and diagnose disease and help select the most appropriate therapy.

“This year’s image demonstrates the clinical utility of PET/CT using the newly approved PET F-18 sodium fluoride bone imaging agent to correctly pinpoint the cause of recurrent pain after surgical placement of spinal fixation hardware,” said Peter Herscovitch, MD, chair of SNM’s scientific program committee.

The study's lead author Andrew Quon, MD, assistant professor of radiology and chief of clinical PET/CT for the molecular imaging program at Stanford University in Stanford, Calif., noted, “The NaF PET/CT image shows the potential of molecular imaging for helping patients with a very common orthopedic problem, and it is available to patients right now. It's very exciting because it reminds us that the future of molecular imaging lies not just in cancer imaging but in a wide range of disease processes beyond oncologic applications.”

Serious spinal instability and disease often necessitate the implantation of hardware such as plates, cages, rods and screws or bone grafts to support the spine. There are many reasons why patients experience pain after initial surgery, including hardware failure and infection, or both. Determining the source of pain can be difficult, especially when patients have complex medical histories.

In this study, a combination of PET/CT and F-18 NaF, an injected radiotracer that uses sodium fluoride to target “hot spots” or areas of high bone turnover and inflammation during imaging, was used to evaluate patients with back pain after spinal surgery. This form of molecular imaging was shown to be highly accurate in determining the culprit of patients' chronic pain by highlighting both the structure of the bone and the physiological processes involved in inflammation, an indication of injury and infection.

For this prospective study, the researchers evaluated 20 patients presenting with spinal pain with PET/CT using F-18 NaF at least eight months after surgery. A total of 24 bone or tissue abnormalities were found in 17 of the 20 subjects. Of the original 20 patients, 12 received exploratory surgery and four participants received local anesthetic nerve blockade, a common and minimally invasive treatment that numbs the affected nerve, providing short-term pain management as an alternative to surgery.

Quon and colleagues found that F-18 NaF PET/CT is highly effective for the evaluation of pain after spinal surgery—in more than 85 percent of cases, this form of molecular imaging was able to identify the exact source of patients' pain.