Thomas Lange1, Benjamin R Knowles1, Michael Herbst1,2, Kaywan Izadpanah3, Maxim Zaitsev1. 1. Department of Radiology, Medical Physics, Medical Center - University of Freiburg, Faculty of Medicine, Freiburg, Germany. 2. John A. Burns School of Medicine, University of Hawaii, Honolulu, Hawaii, USA. 3. Department of Orthopedic and Trauma Surgery, Medical Center - University of Freiburg, Faculty of Medicine, Freiburg, Germany.
Abstract
PURPOSE: To demonstrate improved T2 and T1ρ mapping of patellofemoral cartilage with in situ loading by means of prospective motion correction and to assess load-induced changes in healthy subjects. MATERIALS AND METHODS: Established T2 and T1ρ mapping sequences were augmented with prospective motion correction based on optical tracking. Protocols were optimized for robust imaging of the patellofemoral cartilage at a field strength of 3T. Subjects were positioned in the scanner with knee flexion and in situ loading of the patellofemoral joint was performed with a pneumatic loading device. In a pilot study on a cohort of 10 healthy subjects, load-induced T2 and T1ρ changes were evaluated through measurements with axial loads of 0/20/40 kg. RESULTS: With prospective motion correction and additional lipid saturation, motion artifacts in patellofemoral cartilage magnetic resonance imaging (MRI) with in situ loading could be notably decreased, as demonstrated for T2 mapping. The acquired relaxation maps suggested a T2 /T1ρ decrease in superficial cartilage and a T2 /T1ρ increase in deep cartilage under loading. However, in the quantitative group evaluation of the lateral patellar facet, only T1ρ in superficial cartilage was significantly changed by loading (P ≤ 0.05), while no significant T2 differences for the three loading conditions were observed (P ≥ 0.3). CONCLUSION: Prospective motion correction enables T2 and T1ρ mapping of patellofemoral cartilage with in situ loading and a comparison of the two contrasts in terms of their response to mechanical loading. T1ρ is a more sensitive marker for load-induced patellar cartilage changes than T2 . LEVEL OF EVIDENCE: 3 Technical Efficacy: Stage 1 J. MAGN. RESON. IMAGING 2017;46:452-460.
PURPOSE: To demonstrate improved T2 and T1ρ mapping of patellofemoral cartilage with in situ loading by means of prospective motion correction and to assess load-induced changes in healthy subjects. MATERIALS AND METHODS: Established T2 and T1ρ mapping sequences were augmented with prospective motion correction based on optical tracking. Protocols were optimized for robust imaging of the patellofemoral cartilage at a field strength of 3T. Subjects were positioned in the scanner with knee flexion and in situ loading of the patellofemoral joint was performed with a pneumatic loading device. In a pilot study on a cohort of 10 healthy subjects, load-induced T2 and T1ρ changes were evaluated through measurements with axial loads of 0/20/40 kg. RESULTS: With prospective motion correction and additional lipid saturation, motion artifacts in patellofemoral cartilage magnetic resonance imaging (MRI) with in situ loading could be notably decreased, as demonstrated for T2 mapping. The acquired relaxation maps suggested a T2 /T1ρ decrease in superficial cartilage and a T2 /T1ρ increase in deep cartilage under loading. However, in the quantitative group evaluation of the lateral patellar facet, only T1ρ in superficial cartilage was significantly changed by loading (P ≤ 0.05), while no significant T2 differences for the three loading conditions were observed (P ≥ 0.3). CONCLUSION: Prospective motion correction enables T2 and T1ρ mapping of patellofemoral cartilage with in situ loading and a comparison of the two contrasts in terms of their response to mechanical loading. T1ρ is a more sensitive marker for load-induced patellar cartilage changes than T2 . LEVEL OF EVIDENCE: 3 Technical Efficacy: Stage 1 J. MAGN. RESON. IMAGING 2017;46:452-460.
Authors: Sven Nebelung; Manuel Post; Matthias Knobe; Markus Tingart; Pieter Emans; Johannes Thüring; Christiane Kuhl; Daniel Truhn Journal: Sci Rep Date: 2019-04-11 Impact factor: 4.379
Authors: Oliver Said; Justus Schock; Nils Krämer; Johannes Thüring; Lea Hitpass; Philipp Schad; Christiane Kuhl; Daniel Abrar; Daniel Truhn; Sven Nebelung Journal: MAGMA Date: 2020-04-20 Impact factor: 2.310