Imaging features of intraosseous hemangiomas: beyond the mobile spine and calvarium.

OBJECTIVE: Describe imaging features of intraosseous hemangiomas located outside of the mobile spine and calvarium. MATERIALS AND METHODS: Imaging and medical records were retrospectively reviewed for cases of intraosseous hemangiomas located outside of the calvarium and mobile spine. Evaluation included patient demographics, histologic confirmation, and imaging characteristics. RESULTS: Thirty-six patients were included (25 F, 11 M; mean age 54 ± 17 years, range 10-84 years) with 37 total lesions (70% axial and 30% appendicular skeleton). Mixed lytic and sclerotic features were identified on 83-85% radiographs and CTs. Amorphous increased density mimicking osteoid matrix was present on 38-45% radiographs and CTs. Classic honeycomb or radial pattern was identified on 45% of CTs. Osseous expansion and cortical permeation were common features. CT identified periosteal reaction in 24% of lesions. All hemangiomas had heterogeneous MRI signal and most moderately or avidly enhanced. Intralesional fat was identified on 78% MRIs, often as a minor component and only detected on 24% of CTs. A soft tissue mass was present on 52% of MRIs. FDG PET/CT mean SUVmax of 3.2 ± 0.6 (range 1.9-5.0). Lesional FDG activity relative to background marrow was increased in 75% of lesions. Lesions with cortical permeation had higher metabolic activity versus those without (3.5 ± 0.7 versus 2.2 ± 0.3, p = 0.041). CONCLUSION: Intraosseous hemangiomas outside of the mobile spine and calvarium demonstrate more aggressive imaging features compared to vertebral hemangiomas, including cortical permeation, soft tissue mass, amorphous increased density mimicking osteoid matrix, and increased FDG activity.

Comparison of [18F] FDG-PET/MRI and Clinical Findings for Assessment of Suspected Lumbar Facet Joint Pain: A Prospective Study to Characterize Candidate Nonanatomic Imaging Biomarkers and Potential Impact on Management.

BACKGROUND AND PURPOSE: Prior retrospective studies have suggested that both T2 hyperintensity and gadolinium enhancement on fat-suppressed MR imaging are associated with lumbar facet joint pain, but prospective evaluation of FDG-PET/MR imaging with a standardized protocol and correlation to clinical findings are lacking. The primary aim was to prospectively assess a standardized FDG-PET/MRI protocol in patients with suspected facetogenic low back pain, with determination of the concordance of imaging and clinical findings. MATERIALS AND METHODS: Ten patients with clinically suspected facetogenic low back pain were prospectively recruited with a designation of specific facet joints implicated clinically. Subsequently, patients underwent an FDG-PET/MR imaging examination with gadolinium. Each facet joint was graded for perifacet signal change on MR imaging and FDG activity. The frequency and correlation of MR imaging, FDG-PET, and clinical findings were determined. RESULTS: FDG activity showed high concordance with high overall MR imaging scores (concordance correlation coefficient = 0.79). There was concordance of the clinical side of pain with the side of high overall MR imaging scores and increased FDG activity on 12/20 (60%) sides. Both a high overall MR imaging score (concordance correlation coefficient = 0.12) and FDG-PET findings positive for increased activity (concordance correlation coefficient = 0.10) had low concordance with the specific clinically implicated facet joints. Increased FDG activity or high MR imaging scores or both were present in only 10/29 (34%) facet joints that had been clinically selected for percutaneous intervention. Eleven (11%) facet joints that had not been selected for treatment demonstrated these imaging findings. CONCLUSIONS: There was low concordance of perifacet signal change and FDG activity with clinically implicated facet joints. This could indicate either the potential to change patient management or a lack of biomarker accuracy. Therefore, additional larger randomized studies with the use of comparative medial branch blocks would be useful to further investigate the clinical utility of these findings.