The challenge of identifying the source of pain in patients with both acute and chronic low back pain is well known and motivates our team’s work.1 Specifically, our study focused on defining improved imaging biomarkers for facetogenic low back pain and related disability. Accurately localizing the precise facet joint(s) giving rise to a patient’s symptoms is often elusive, even with thorough history, physical examination, and anatomic imaging.1-2 While diagnostic blocks remain the criterion standard method for identifying symptomatic lumbar facet joints, this is an invasive and time-consuming procedure that is not feasible as a routine screening tool for all patients who present with nonspecific low back pain.
Over the past several decades, structural evaluation of facet joints with CT and MRI has been pursued to guide treating physicians to the source of low back pain. Unfortunately, structural alterations associated with degenerative and painful facet disease, such as cartilage loss, joint space narrowing, bony hypertrophy, synovial and capsular thickening, and intra-articular fluid accumulation, are all commonly observed in an asymptomatic population and may be part of the aging process.3 With dynamic [18F]-sodium fluoride positron emission tomography and MRI (NaF-PET-MRI), we attempted to correlate physiologic measures of bone turnover as a potentially more specific biomarker of facetogenic low back pain and related disability.4
If the preliminary data from our study can be validated in a larger cohort with prospective data collection, we believe dynamic NaF-PET could play a more central role in the diagnosis of facetogenic low back pain. Improved noninvasive diagnosis could potentially decrease the number of unnecessary diagnostic injection procedures, increase the efficiency of therapeutic injection and ablation procedures, and guide levels of surgical fusion for degenerative facet disease treatment.