Abstract
ABSTRACTThis study characterized the distribution of [18F]‐sodium fluoride (NaF) uptake and blood flow in the femur and acetabulum in hip osteoarthritis (OA) patients to find associations between bone remodeling and cartilage composition in the presence of morphological abnormalities using simultaneous positron emission tomography and magnetic resonance imaging (PET/MR), quantitative magnetic resonance imaging (MRI) and femur shape modeling. Ten patients underwent a [18F]‐NaF PET/MR dynamic scan of the hip simultaneously with: (i) fast spin‐echo CUBE for morphology grading and (ii) T 1ρ/T 2 magnetization‐prepared angle‐modulated partitioned k‐space spoiled gradient echo snapshots for cartilage, bone segmentation, bone shape modeling, and T 1ρ/T 2 quantification. The standardized uptake values (SUVs) and Patlak kinetic parameter (K pat) were calculated for each patient as PET outcomes, using an automated post‐processing pipeline. Shape modeling was performed to extract the variations in bone shapes in the patients. Pearson's correlation coefficients were used to study the associations between bone shapes, PET outcomes, and patient reported pain. Direct associations between quantitative MR and PET evidence of bone remodeling were established in the acetabulum and femur. Associations of shaft thickness with SUV in the femur (p = 0.07) and K pat in the acetabulum (p = 0.02), cam deformity with acetabular score (p = 0.09), osteophytic growth on the femur head with K pat (p = 0.01) were observed. Pain had increased correlations with SUV in the acetabulum (p = 0.14) and femur (p = 0.09) when shaft thickness was accounted for. This study demonstrated the ability of [18F]‐NaF PET‐MRI, 3D shape modeling, and quantitative MRI to investigate cartilage‐bone interactions and bone shape features in hip OA, providing potential investigative tools to diagnose OA. © 2019 The Authors. Journal of Orthopaedic Research ® published by Wiley Periodicals, Inc. on behalf of Orthopaedic Research Society J Orthop Res 37:2671–2680, 2019
Highlights
Osteoarthritis (OA) is the most common debilitating joint disease, affecting more than 25% of the adult population
The bone marrow edema (BME) lesion score showed a high correlation with the standardized uptake values (SUVs) in the acetabulum, which increased when corrected for age
For some of the cases, elevated SUV was found in regions that did not depict abnormal morphological magnetic resonance imaging (MRI) findings, and these elevations were accompanied by higher T1ρ and T2 values
Summary
Osteoarthritis (OA) is the most common debilitating joint disease, affecting more than 25% of the adult population. T1ρ and T2 relaxation times provide a measure of proteoglycan content and collagen orientation, respectively, reflecting the cartilage biochemistry and composition.[11,12] In a previous longitudinal study, patients with hip OA, who demonstrated elongated T1ρ and T2 relaxation times, developed morphological cartilage degeneration, indicating that T1ρ and T2 relaxation times may be biomarkers for early OA.[13] The three‐dimensional (3D) proximal femur shape variations were shown to have associations with morphological and compositional markers of hip joint degeneration as well as associations with demographics.[6] In addition, studies have shown that [18F]‐ sodium fluoride (NaF) positron emission tomography and magnetic resonance imaging (PET/MR) is capable of imaging significant bone and cartilage interactions in the knee joint.[14,15] Associations between pain and tracer uptake were seen in the absence of morphological lesions in the cartilage.[14] An increase in tracer uptake in the presence of subchondral bone lesions was observed in the knee, concluding that PET/MR may detect metabolic abnormalities in the subchondral bone before they are seen on MRI.[15] the feasibility of [18F]‐NaF PET/MR to image bone cartilage interactions in the knee has been studied, to the best of our knowledge, no previous studies have explored the relationships between bone–cartilage interactions and bone shape in the hip joint using [18F]‐NaF PET/MR. We hypothesized that patients with cartilage lesions would demonstrate higher tracer uptake in the bone surrounding the lesions, indicating bone remodeling accompanying the cartilage degeneration, and that the coxa valga femur shape and cam impingment type abnormalities would show higher tracer uptake on account of bone remodeling
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
