Planar and high-resolution SPECT bone imaging in the diagnosis of facet syndrome

This study's goals were to determine the appearance of potentially symptomatic facet joints on planar and high-resolution SPECT radionuclide bone imaging, relate the relative sensitivity of the two techniques and assess the predictive value in a clinical setting.

Fifty-eight consecutive patients referred with a diagnosis of possible facet syndrome were imaged during the same visit using both a well-established planar and a SPECT technique developed to emphasize high spatial resolution. The standard of reference included facet injections with a marcaine and steroid mixture, with review of a pain journal completed by the patient included in the followup criteria.

In the 43 patients comprising the final study group, 7 were diagnosed with facet syndrome, 5 with abnormal planar images and 7 with abnormal SPECT images. A total of 10 facet joints with abnormal increased uptake were seen on SPECT which were not demonstrated on planar imaging. There was high sensitivity (100% SPECT, 71% planar), but somewhat lower specificity (71% SPECT, 76% planar). The negative predictive value was high (100% SPECT, 93% planar). Radionuclide bone imaging additionally discovered a nonfacet joint etiology for patient symptoms in 16 of the 43 patients.

Higher spatial resolution SPECT images are better accepted by referring physicians who correlate them with CT or MR images. The high negative predictive value allows radionuclide bone imaging to be used to select appropriate patients to undergo the invasive facet injection procedure.