Magnetic resonance-guided focused ultrasound (MRgFUS) is a noninvasive, incisionless, radiation-free technology used to ablate tissue deep within the body. This technique has gained increased popularity following FDA approval for treatment of pain related to bone metastases and limited approval for treatment of osteoid osteoma. MRgFUS delivers superior visualization of soft tissue targets in unlimited imaging planes and precision in targeting and delivery of thermal dose which is all provided during real-time monitoring using MR thermometry. This paper provides an overview of the common musculoskeletal applications of MRgFUS along with updates on clinical outcomes and discussion of future applications.

Facet joint osteoarthritis/arthropathy of the spine is a common cause of back and neck pain that frequently overlaps clinically with other diseases of the spine. Because of the possible overlap, it is crucial to have an accurate diagnostic strategy, especially when determining the management approach. Various strategies have been suggested and adopted, with several these still being used in clinics. Over the years, because of the disadvantages of single-modality imaging methods (computed tomography, magnetic resonance imaging, single-photon emission computed tomography), the interest in radiologic examination started to move toward hybrid imaging techniques. Although the data are mixed, many initial studies have shown promise. However, there are relatively few data with comparative medial branch blocks, and further investigation is needed. Given the advantages and disadvantages of these new techniques, the imaging results have to be interpreted within clinical context and with consideration of the current state of knowledge in the decision-making process.

BACKGROUND: The pathogenesis of synovial cysts is largely unknown; however, they have been increasingly thought of as markers of spinal facet instability and typically associated with degenerative spondylosis. We specifically investigated the incidence of concomitant synovial cysts with underlying degenerative spondylolisthesis.
METHODS: A literature search was performed using 4 online databases to assess the association between lumbar synovial cysts and degenerative spinal pathological features. Meta-analyses were performed on the prevalence rates of coexisting degenerative spinal pathological entities and treatment modalities. A random effects model was used to calculate the mean and 95% confidence intervals.
RESULTS: A total of 17 studies encompassing 824 cases met the inclusion criteria. The pooled prevalence rates of concurrent spondylolisthesis, facet arthropathy, and degenerative disc disease at the same level of the synovial cysts were 42.5% (range, 39.0%-46.1%), 89.3% (range, 79.0%-94.8%), and 48.8% (range, 43.8%-53.9%), respectively. Among these, patients with coexisting spondylolisthesis were more likely to undergo spinal fusion surgery (vs. laminectomy alone) and reoperation than were patients without spondylolisthesis with a pooled odds ratio of 11.5 (95% confidence interval, 4.5-29.1; P < 0.0001) and 2.0 (95% confidence interval, 0.9-4.2; P = 0.088), respectively.
CONCLUSIONS: Patients with a combination of synovial cysts and degenerative spondylolisthesis are more likely to undergo spinal fusion surgery than laminectomy alone compared with patients with synovial cysts and no preoperative spondylolisthesis. Furthermore, patients with synovial cysts and spondylolisthesis are more likely to require additional fusion surgery. The results from the present review lend credence to the argument that synovial cyst herniation might be a manifestation of an unstable spinal level.

OBJECTIVE: Standard imaging techniques have low predictive value for identifying sources of neck pain. Single-photon emission computed tomography (SPECT) imaging in conjunction with computed tomography (CT) provides the sensitivity of bone scanning for areas of high metabolic activity with the sensitivity of CT for anatomic localization. We evaluated the usefulness of SPECT-CT imaging in identifying pain generators in upper cervical facet arthropathy.
METHODS: In a retrospective study, we reviewed 7 patients (mean age, 68.7 years) who underwent diagnostic SPECT-CT imaging for upper cervical neck pain at our institution from August 2011 to February 2015. We assessed SPECT-CT radiotracer uptake and postoperative neck disability index (NDI) and visual analog scale (VAS) scores.
RESULTS: Mean preoperative NDI and VAS scores were 42% (range, 34%-72%) and 7/10 (range, 5-8), respectively. SPECT-CT showed increased radiotracer uptake and inflammation at the level of pain generation indicated by history and physical examination. Intraoperatively, all patients had corresponding facet hypertrophy with degeneration at the site of increased radiotracer uptake. The mean postoperative NDI and VAS scores at 9 months were 23% (0%-54%) and 2/10 (0-5), respectively, representing improvements of 20% (P = 0.025) and 4 (P = 0.0028), respectively.
CONCLUSIONS: SPECT-CT imaging of the upper cervical spine is a potentially sensitive diagnostic test that can implicate pain generators with increased metabolic activity. We propose that SPECT-CT may be a useful adjunct in the workup for neck pain secondary to facet arthropathy that could obviate diagnostic injections.