title: Zonal differences in meniscus MR relaxation times in response to in vivo static loading in knee osteoarthritis.
abstract: This study assessed the effects of static loading on MRI relaxation times of menisci in individuals with and without radiographic knee OA. High-resolution fast spin-echo (FSE) and T(1ρ)/T(2) relaxation time MR sequences were obtained with and without loading at 50% body weight in 124 subjects. T(1ρ)/T(2) relaxation times were calculated in menisci, and meniscus lesions were assessed through clinical grading. Student's t-test compared OA and control unloaded relaxation times as well as within-group changes with loading, Generalized Linear Models evaluated zonal variation, and ANCOVA compared loading response between groups. Unloaded T(1ρ) and T(2) in the middle and inner zones of the lateral anterior horn and outer zone of the medial posterior horn were significantly higher in OA and suggest that meniscal OA change occurs unevenly. Zonal T(1ρ) and T(2) showed differing patterns between anterior and posterior horns, suggesting differences in macromolecular organization. Significant increases with loading were seen largely in the T(2) of controls and less frequently in subjects with OA. In the medial posterior horn, T(1ρ) and T(2) decreased with loading in OA but changed negligibly in controls; these significantly different loading responses between groups may indicate load transmission failure in OA menisci.
authors.affiliation: Musculoskeletal Quantitative Imaging Research, Department of Radiology and Biomedical Imaging, University of California, San Francisco, California.
authors.forename: Nathaniel E
authors.initials: NE
authors.lastname: Calixto
authors.affiliation: Musculoskeletal Quantitative Imaging Research, Department of Radiology and Biomedical Imaging, University of California, San Francisco, California.|Division of Physical Therapy, College of Health Professions, Medical University of South Carolina, Charleston, South Carolina.
authors.forename: Deepak
authors.initials: D
authors.lastname: Kumar
authors.affiliation: Musculoskeletal Quantitative Imaging Research, Department of Radiology and Biomedical Imaging, University of California, San Francisco, California.|Engineering Product Development, Singapore University of Technology and Design, Singapore.
authors.forename: Karupppasamy
authors.initials: K
authors.lastname: Subburaj
authors.affiliation: Musculoskeletal Quantitative Imaging Research, Department of Radiology and Biomedical Imaging, University of California, San Francisco, California.
authors.forename: Justin
authors.initials: J
authors.lastname: Singh
authors.affiliation: Musculoskeletal Quantitative Imaging Research, Department of Radiology and Biomedical Imaging, University of California, San Francisco, California.
authors.forename: Joseph
authors.initials: J
authors.lastname: Schooler
authors.affiliation: Musculoskeletal Quantitative Imaging Research, Department of Radiology and Biomedical Imaging, University of California, San Francisco, California.
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Nardo
authors.affiliation: Musculoskeletal Quantitative Imaging Research, Department of Radiology and Biomedical Imaging, University of California, San Francisco, California.
authors.forename: Xiaojuan
authors.initials: X
authors.lastname: Li
authors.affiliation: Musculoskeletal Quantitative Imaging Research, Department of Radiology and Biomedical Imaging, University of California, San Francisco, California.|Department of Physical Therapy, University of California, San Francisco, California.
authors.forename: Richard B
authors.initials: RB
authors.lastname: Souza
authors.affiliation: Musculoskeletal Quantitative Imaging Research, Department of Radiology and Biomedical Imaging, University of California, San Francisco, California.
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Link
authors.affiliation: Musculoskeletal Quantitative Imaging Research, Department of Radiology and Biomedical Imaging, University of California, San Francisco, California.
authors.forename: Sharmila
authors.initials: S
authors.lastname: Majumdar
mesh_terms: D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008592:Menisci, Tibial / Q000473:pathology / Q000503:physiopathology*; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000473:pathology / Q000503:physiopathology*; D016474:Weight-Bearing
keywords: T1ρ; T2; WORMS; imaging; meniscus