Joint Program in Nuclear Medicine

Facet Disease and the Future of Bone Imaging

Barry Julius, MD
Scott Britz-Cunningham, MD

October 14, 2003

Presentation

A 65-year-old male with history of prostate cancer presented with neck pain upon rotation.

Imaging Technique

27.0 mCi of Tc-99m MDP was administered intravenously at the right antecubital fossa. Anterior and posterior whole body delayed planar imaging and SPECT imaging of the cervical spine were subsequently performed.

Imaging Findings

Planar bone scan imaging demonstrates a moderate focus of increased uptake at the left aspect of the approximate C3/4 level (shown by arrow) as well as increased uptake at the right knee patella and medial compartment (arrow head) likely related to degenerative changes. There is also mild to moderate increased focal uptake at the right ischial tuberosity most likely related to osseous spurring or entesopathy. And there is bilateral first MCP foci likely related to osteoarthitic changes. SPECT imaging of the cervical spine confirms abnormal uptake overlying the approximate left C3/4 level (shown by arrows).

MRI of the cervical spine demonstrates findings consistent with hypertrophy of the facets at the left C3/4 level (shown by arrows) on the T1 and T2 axial and sagittal images. There is also a T2 dark soft tissue lesion eroding the dens noted on the sagittal image consistent with pannus formation.

Diagnosis

Left C3/4 facet disease, which is the likely cause of the patient’s symptomatology and clinical history.

Discussion

Introduction:

Facet disease is a common cause for chronic back pain with a prevalence of disease ranging from 8-75%. One study demonstrated that it may be the most common cause of back pain based upon osteoporotic patients that were treated for facet disease. The pathophysiology causing the pain is multifactorial and includes pain produced from prostaglandins and inflammatory mediators, facet capsular autonomic nerve irritation, and nociceptive substance P. These factors may be stimulated by a number of different processes including inflammatory arthritis, osteoarthritis, microtrauma, and distension and inflammation of the synovial capsule.

Imaging Modalities:

The primary imaging modalities at the present time are plain film, CT scan, MRI, and Tc-99m–MDP bone scintigraphy.

Plain films, CT scan, and MRI demonstrate anatomic correlation of hypertrophic changes at the facet joint. These imaging modalities have not been correlated with patient symptomatology. Plain film and CT scan can demonstrate abnormal facet joint osseous hypertrophy. MRI will also show osseous hypertrophy that is T1 and T2 dark at the level of the facet joint. These modalities are useful for confirming localization of osseous scinitgraphic findings.
Tc-99m MDP planar imaging is correlated with patient symptomatology in patients with lower back pain and abnormal facet uptake. One study demonstrated a sensitivity of 71% and specificity of 76% for back pain corresponding to the imaging findings of increased uptake at a facet joint. No other studies have correlated imaging of facet disease with patients’ symptoms of back pain. All information is currently extrapolated from this study to imaging of the cervical spine. Imaging of the cervical spine currently suffers from a lack of resolution of anatomy in this region.
Tc-99m MDP imaging also detected multiple additional causes that can simulate the findings of facet disease pain in patients including spinal stenosis, ischial tendonitis, and lumbar strain.
Tc-99m MDP SPECT imaging improves the sensitivity of bone scanning for patients with back pain. The same paper discussed a total sensitivity and specificity for SPECT imaging of the lumbar spine of 100% and 71% respectively.

Treatment:

Multiple treatment modalites are available for patients with facet disease. These include multiple noninvasive and invasive treatments from physical therapy, steroid or local anesthetic injection, radiofrequency ablation of the facet joint, to surgical fusion. The current literature does not support any mitigation of the patient symptoms from the most invasive approach, surgical fusion, or the least invasive approach, physical therapy.

Steroid or local anesthetic is often injected for relief of symptoms from facet disease with a 10-63% success rate over a short term time period. At Brigham and Women Hospital, this is a common procedure for relief of symptoms. Radiofrequency ablation also demonstrates a large range of success rates from 17-86% as well.

Potential Future Facet Imaging with Flouride Ion Positron Emission Tomography:

The mechanism of uptake of fluorine ion is similar to MDP in that it acts through chemisorption. Specifically, F-18 ion replaces the hydroxyl ion on hydroxapatite crystal to form fluoroapatite within the osseous matrix. With this mechanism of chemisorption, the fluorine ion binds more efficiently to the osseous matrix compared to Tc99m-MDP. In fact, one study demonstrated 3 to 10 times greater binding efficiency to metastatic lesions compared to Tc99m-MDP. Twice as many osseous lesions were noted of which several changed patient management. And, positron emission tomography improves the spatial resolution of the study. Therefore, fluoride ion imaging may be a superior imaging agent for detection of symptom specific levels of facet disease. And, this may help to specify the exact level of treatment for the interventionalist that can sometimes be difficult with SPECT Tc99m-MDP. Further study is needed.

References

1. Cook GJ. Hannaford E. See M. Clarke SE Fogelman I. The value of bone scintigraphy in the evaluation of osteoporotic patients with back pain. Scandinavian Journal of Rheumatology. 2002; 314(4)245-8.

2. Holder LE. Marchin JL Asdourian PL. Links JM. Sexton CC. Planar and high resolution SPECT bone imaging in the diagnosis of facet syndrome. J Nucl Med 1995; 36:37-44.

3. Ryan PJ. Evans PA Gibson T. Fogelman I. Chronic low back pain: comparison of bone SPECT with radiography and CT. Radiology 1992; 182:849-854.

4. Schirrmeister H. Guhlmann A. Eisner K, et al: Sensitivity in detecting osseous lesions depends on anatomic localization: Planar bone scintigraphy versus 18F PET. J Nucl Med 1999; 40:1623-1629.

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J. Anthony Parker, MD PhD, Tony_Parker@CareGroup.Harvard.edu