Quantitative Imaging of Bone-Cartilage Interactions in ACL-Injured Patients with PET-MRI
Osteoarthritis (OA) is a degenerative whole-joint disease that affects more than half of the population during their lives and is the leading cause of disability worldwide. Diagnostic imaging of osteoarthritis is often limited to x-ray, but more sensitive and specific imaging is a critical need for development of disease-modifying treatments. Advanced MRI methods have shown promise for assessment of tissue microstructure in OA, but are limited to soft tissues such as cartilage. In this work, we evaluate simultaneous 18F-NaF PET/MR Imaging to study early changes in bone and cartilage in ACL-injured knees, which are at known risk for development of OA. We found that ACL-injured knee joints demonstrated significantly increased 18F-NaF PET uptake, representative of increased metabolic bone activity, compared to their unaffected contralateral knees. This suggests that increased metabolic bone activity detected with 18F-NaF PET can serve as an important marker of early OA and progression of disease. Further we observed a spatial correlation between increased subchondral bone remodeling on 18F-NaF PET and adjacent changes in the cartilage microstructure on MRI T2 relaxation time maps. This result supports the hypothesis of a spatial relationship between early degenerative OA changes across bone and cartilage. 18F-NaF PET-MRI thus holds tremendous potential to provide biomarkers that quantitatively assess early progression of OA, which are crucial to develop and evaluate disease-modifying treatments, and ultimately arrest or reverse the progression of OA.
Kogan F, Fan AP, Monu U, Iagaru A, Hargreaves BA, Gold GE. Quantitative imaging of bone-cartilage interactions in ACL-injured patients with PET-MRI. Osteoarthritis Cartilage. 2018 Jun;26(6):790-6.
Uche Monu is an alumnus of the BMR group