Characterization of bone perfusion by dynamic contrast-enhanced magnetic resonance imaging and positron emission tomography in the Dunkin-Hartley guinea pig model of advanced osteoarthritis.

Publication Type	Academic Article
Authors	Dyke J, Synan M, Ezell P, Ballon D, Racine J, Aaron R
Journal	J Orthop Res
Volume	33
Issue	3
Pagination	366-72
Date Published	11/19/2014
ISSN	1554-527X
Keywords	Bone and Bones, Magnetic Resonance Imaging, Osteoarthritis, Positron-Emission Tomography
Abstract	This study characterizes changes in subchondral bone circulation in OA and examines relationships to bone structure and cartilage degeneration in Dunkin-Hartley guinea pigs. We have used dynamic contrast-enhanced MRI (DCE-MRI) and PET, with pharmacokinetic modeling, to characterize subchondral bone perfusion. Assessments are made of perfusion kinetics and vascular permeability by MRI, and blood volume and flow, and radionuclide incorporation into bone, by PET. These parameters are compared to cartilage lesion severity and bone histomorphometry. Assessments of intraosseous thrombi are made morphologically. Prolonged signal enhancement during the clearance phase of MRI correlated with OA severity and suggested venous stasis. Vascular permeability was not increased indicating that transvascular migration of contrast agent was not responsible for signal enhancement. Intraosseous thrombi were not observed. Decreased perfusion associated with severe OA was confirmed by PET and was associated with reduced radionuclide incorporation and osteoporosis. MRI and PET can be used to characterize kinetic parameters of circulation in OA and correlate them with subchondral bone metabolism of interest to the pathophysiology of OA. The significance of these observations may lie in alterations induced in the expression of cytokines by OA osteoblasts that are related to bone remodeling and cartilage breakdown.
DOI	10.1002/jor.22768
PubMed ID	25410523
PubMed Central ID	PMC4346481