Oliver Said1, Justus Schock2,3, Nils Krämer1, Johannes Thüring1, Lea Hitpass1, Philipp Schad1, Christiane Kuhl1, Daniel Abrar2, Daniel Truhn1,3, Sven Nebelung4. 1. Department of Diagnostic and Interventional Radiology, Aachen University Hospital, Aachen, Germany. 2. Department of Diagnostic and Interventional Radiology, Medical Faculty, University Hospital Düsseldorf, University Dusseldorf, Moorenstraße 5, 40225, Düsseldorf, Germany. 3. Institute of Computer Vision and Imaging, RWTH University Aachen, Aachen, Germany. 4. Department of Diagnostic and Interventional Radiology, Medical Faculty, University Hospital Düsseldorf, University Dusseldorf, Moorenstraße 5, 40225, Düsseldorf, Germany. sven.nebelung@med.uni-duesseldorf.de.
Abstract
OBJECTIVE: Beyond static assessment, functional techniques are increasingly applied in magnetic resonance imaging (MRI) studies. Stress MRI techniques bring together MRI and mechanical loading to study knee joint and tissue functionality, yet prototypical axial compressive loading devices are bulky and complex to operate. This study aimed to design and validate an MRI-compatible pressure-controlled varus-valgus loading device that applies loading along the joint line. METHODS: Following the device's thorough validation, we demonstrated proof of concept by subjecting a structurally intact human cadaveric knee joint to serial imaging in unloaded and loaded configurations, i.e. to varus and valgus loading at 7.5 kPa (= 73.5 N), 15 kPa (= 147.1 N), and 22.5 kPa (= 220.6 N). Following clinical standard (PDw fs) and high-resolution 3D water-selective cartilage (WATSc) sequences, we performed manual segmentations and computations of morphometric cartilage measures. We used CT and radiography (to quantify joint space widths) and histology and biomechanics (to assess tissue quality) as references. RESULTS: We found (sub)regional decreases in cartilage volume, thickness, and mean joint space widths reflective of areal pressurization of the medial and lateral femorotibial compartments. DISCUSSION: Once substantiated by larger sample sizes, varus-valgus loading may provide a powerful alternative stress MRI technique.
OBJECTIVE: Beyond static assessment, functional techniques are increasingly applied in magnetic resonance imaging (MRI) studies. Stress MRI techniques bring together MRI and mechanical loading to study knee joint and tissue functionality, yet prototypical axial compressive loading devices are bulky and complex to operate. This study aimed to design and validate an MRI-compatible pressure-controlled varus-valgus loading device that applies loading along the joint line. METHODS: Following the device's thorough validation, we demonstrated proof of concept by subjecting a structurally intact human cadaveric knee joint to serial imaging in unloaded and loaded configurations, i.e. to varus and valgus loading at 7.5 kPa (= 73.5 N), 15 kPa (= 147.1 N), and 22.5 kPa (= 220.6 N). Following clinical standard (PDw fs) and high-resolution 3D water-selective cartilage (WATSc) sequences, we performed manual segmentations and computations of morphometric cartilage measures. We used CT and radiography (to quantify joint space widths) and histology and biomechanics (to assess tissue quality) as references. RESULTS: We found (sub)regional decreases in cartilage volume, thickness, and mean joint space widths reflective of areal pressurization of the medial and lateral femorotibial compartments. DISCUSSION: Once substantiated by larger sample sizes, varus-valgus loading may provide a powerful alternative stress MRI technique.
Authors: K Subburaj; R B Souza; C Stehling; B T Wyman; M-P Le Graverand-Gastineau; T M Link; X Li; S Majumdar Journal: J Orthop Res Date: 2011-12-07 Impact factor: 3.494
Authors: Garry E Gold; Thor F Besier; Christine E Draper; Deanna S Asakawa; Scott L Delp; Gary S Beaupre Journal: J Magn Reson Imaging Date: 2004-09 Impact factor: 4.813
Authors: Hongsheng Wang; Matthew F Koff; Hollis G Potter; Russell F Warren; Scott A Rodeo; Suzanne A Maher Journal: J Biomech Date: 2015-08-13 Impact factor: 2.712
Authors: Lawrence L Buchan; Honglin Zhang; Sujith Konan; Ingrid Heaslip; Charles R Ratzlaff; David R Wilson Journal: J Orthop Res Date: 2015-09-08 Impact factor: 3.494
Authors: Sebastian Cotofana; Felix Eckstein; Wolfgang Wirth; Richard B Souza; Xiaojuan Li; Bradley Wyman; Marie-Pierre Hellio-Le Graverand; Thomas Link; Sharmila Majumdar Journal: Eur Radiol Date: 2011-03-30 Impact factor: 5.315