title: Functional MR Imaging Mapping of Human Articular Cartilage Response to Loading.
abstract: Purpose To determine if multiparametric magnetic resonance (MR) imaging mapping can be used to quantify the response to loading of histologically intact human knee cartilage. Materials and Methods Institutional review board approval and written informed consent were obtained. Twenty macroscopically intact cartilage-bone samples were obtained from the central lateral femoral condyles in 11 patients undergoing total knee replacement. A clinical 3.0-T MR imaging system was used to generate T1, T1ρ, T2, and T2* maps with inversion recovery, spin-lock multiple gradient-echo, multiple spin-echo, and multiple gradient-echo sequences. Serial mapping was performed at three defined strain levels (strain 0 [δ0], 0%; strain 1 [δ1/2], 19.8% ± 4.6 [standard deviation]; strain 2 [δ1], 39.5% ± 9.3) by using displacement-controlled static indentation loading. The entire sample and specific cartilage zones (superficial zone [SZ], transitional zone [TZ], and deep zone [DZ]) and regions (subpistonal area [SPA] and peripistonal area [PPA]) were defined as regions of interest. Upon log transformation, repeated measures analysis of variance was used to detect groupwise regional and zonal differences. Load-induced relative changes were determined and analyzed by using paired Student t test and Spearman correlation. Biomechanical testing (unconfined compression) and histologic assessment (Mankin score) served as the reference standard. Results All samples were histologically intact. Strain-related decreases were found at the SZ and TZ for T1 and T2*; for T1ρ, increases were seen in all zones; and for T2, increases were seen at the SZ and PPA only. Significant parameter changes in the entire sample depth of SPA versus PPA were found for δ1/2(T1ρ, 14% ± 12 vs 6% ± 9) and δ1(T1, -4% ± 5 vs -1% ± 3; T1ρ, 13% ± 12 vs 7% ± 7; T2*, -9% ± 12 vs -2% ± 8). SPA versus PPA changes were significant at the SZ and TZ (T1), TZ and DZ (T1ρ), and SZ (T2*). No significant correlations were found between relative changes and biomechanical or histologic parameters. Conclusion Serial multiparametric MR imaging mapping can be used to evaluate cartilage beyond mere static analysis and may provide the basis for more refined graduation strategies of cartilage degeneration.©RSNA, 2016 Online supplemental material is available for this article.
authors: From the Department of Orthopaedics (S.N., B.S., S.O., M.T., B.R., H.J.), Department of Diagnostic and Interventional Radiology (S.N., C.K., D.T.), and Department of Dental Materials and Biomaterials Research (S.R., H.F.), Aachen University Hospital, Pauwelsstrasse 30, 52074 Aachen, Germany; and Institute of Anatomy and Cell Biology, RWTH Aachen University, Aachen, Germany (S.N., T.P.).
authors: Sven
authors: S
authors: Nebelung
authors: From the Department of Orthopaedics (S.N., B.S., S.O., M.T., B.R., H.J.), Department of Diagnostic and Interventional Radiology (S.N., C.K., D.T.), and Department of Dental Materials and Biomaterials Research (S.R., H.F.), Aachen University Hospital, Pauwelsstrasse 30, 52074 Aachen, Germany; and Institute of Anatomy and Cell Biology, RWTH Aachen University, Aachen, Germany (S.N., T.P.).
authors: Björn
authors: B
authors: Sondern
authors: From the Department of Orthopaedics (S.N., B.S., S.O., M.T., B.R., H.J.), Department of Diagnostic and Interventional Radiology (S.N., C.K., D.T.), and Department of Dental Materials and Biomaterials Research (S.R., H.F.), Aachen University Hospital, Pauwelsstrasse 30, 52074 Aachen, Germany; and Institute of Anatomy and Cell Biology, RWTH Aachen University, Aachen, Germany (S.N., T.P.).
authors: Simon
authors: S
authors: Oehrl
authors: From the Department of Orthopaedics (S.N., B.S., S.O., M.T., B.R., H.J.), Department of Diagnostic and Interventional Radiology (S.N., C.K., D.T.), and Department of Dental Materials and Biomaterials Research (S.R., H.F.), Aachen University Hospital, Pauwelsstrasse 30, 52074 Aachen, Germany; and Institute of Anatomy and Cell Biology, RWTH Aachen University, Aachen, Germany (S.N., T.P.).
authors: Markus
authors: M
authors: Tingart
authors: From the Department of Orthopaedics (S.N., B.S., S.O., M.T., B.R., H.J.), Department of Diagnostic and Interventional Radiology (S.N., C.K., D.T.), and Department of Dental Materials and Biomaterials Research (S.R., H.F.), Aachen University Hospital, Pauwelsstrasse 30, 52074 Aachen, Germany; and Institute of Anatomy and Cell Biology, RWTH Aachen University, Aachen, Germany (S.N., T.P.).
authors: Björn
authors: B
authors: Rath
authors: From the Department of Orthopaedics (S.N., B.S., S.O., M.T., B.R., H.J.), Department of Diagnostic and Interventional Radiology (S.N., C.K., D.T.), and Department of Dental Materials and Biomaterials Research (S.R., H.F.), Aachen University Hospital, Pauwelsstrasse 30, 52074 Aachen, Germany; and Institute of Anatomy and Cell Biology, RWTH Aachen University, Aachen, Germany (S.N., T.P.).
authors: Thomas
authors: T
authors: Pufe
authors: From the Department of Orthopaedics (S.N., B.S., S.O., M.T., B.R., H.J.), Department of Diagnostic and Interventional Radiology (S.N., C.K., D.T.), and Department of Dental Materials and Biomaterials Research (S.R., H.F.), Aachen University Hospital, Pauwelsstrasse 30, 52074 Aachen, Germany; and Institute of Anatomy and Cell Biology, RWTH Aachen University, Aachen, Germany (S.N., T.P.).
authors: Stefan
authors: S
authors: Raith
authors: From the Department of Orthopaedics (S.N., B.S., S.O., M.T., B.R., H.J.), Department of Diagnostic and Interventional Radiology (S.N., C.K., D.T.), and Department of Dental Materials and Biomaterials Research (S.R., H.F.), Aachen University Hospital, Pauwelsstrasse 30, 52074 Aachen, Germany; and Institute of Anatomy and Cell Biology, RWTH Aachen University, Aachen, Germany (S.N., T.P.).
authors: Horst
authors: H
authors: Fischer
authors: From the Department of Orthopaedics (S.N., B.S., S.O., M.T., B.R., H.J.), Department of Diagnostic and Interventional Radiology (S.N., C.K., D.T.), and Department of Dental Materials and Biomaterials Research (S.R., H.F.), Aachen University Hospital, Pauwelsstrasse 30, 52074 Aachen, Germany; and Institute of Anatomy and Cell Biology, RWTH Aachen University, Aachen, Germany (S.N., T.P.).
authors: Christiane
authors: C
authors: Kuhl
authors: From the Department of Orthopaedics (S.N., B.S., S.O., M.T., B.R., H.J.), Department of Diagnostic and Interventional Radiology (S.N., C.K., D.T.), and Department of Dental Materials and Biomaterials Research (S.R., H.F.), Aachen University Hospital, Pauwelsstrasse 30, 52074 Aachen, Germany; and Institute of Anatomy and Cell Biology, RWTH Aachen University, Aachen, Germany (S.N., T.P.).
authors: Holger
authors: H
authors: Jahr
authors: From the Department of Orthopaedics (S.N., B.S., S.O., M.T., B.R., H.J.), Department of Diagnostic and Interventional Radiology (S.N., C.K., D.T.), and Department of Dental Materials and Biomaterials Research (S.R., H.F.), Aachen University Hospital, Pauwelsstrasse 30, 52074 Aachen, Germany; and Institute of Anatomy and Cell Biology, RWTH Aachen University, Aachen, Germany (S.N., T.P.).
authors: Daniel
authors: D
authors: Truhn
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee; D001696:Biomechanical Phenomena; D002358:Cartilage, Articular / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000601:surgery*; D011446:Prospective Studies; D016474:Weight-Bearing