MR-Compatible Compression Device for In-Vitro Evaluation of Biomechanical Properties of Cartilage

Abstract

Objective: Purpose of the paper is to present and validate a device for cartilage compression for assessment of MR parameters (T1, T2, ADC) in cartilage explants before, during and after compression operating with novel features. Design: This device fits into a BGA-12 micro-imaging gradient system capable of delivering 200mT/m. A 35 mm inner diameter resonator was used. The reproducibility and accuracy of cartilage compression possible with the device were evaluated. Sixteen human cartilage explants from knee joints were examined by delayed Gadolinium enhancement MRI of cartilage (dGEMRIC) for T1 mapping, T2 mapping and ADC measurements.Results: Cartilage compression studies demonstrated both low inter-observer (CV 4.7 %) and intra-observer (CV 11.9 %) variation. No undesired movements were observed. The compressive piston could be moved with high accuracy (error ~ 1.07 %). The waterproof chamber of the compression device allowed contrast enhanced T1 mapping without repositioning the cartilage samples. Preliminary results of MR parameters depending on compression are presented. Conclusions: In vitro MR cartilage compression studies are feasible with the custom-build device with high reproducibility and accuracy. Valuable information about biomechanical cartilage properties can be recorded using this device.

The Relationship between MR Parameters and Biomechanical Quantities of Loaded Human Articular Cartilage in Osteoarthritis: An In-Vitro Study

“…The micro-gradient system is actively shielded and water-cooled with an aperture diameter of 25 mm. In order to fasten the rig into the whole-body 3T scanner two nylon screws fixed the rig to the appropriate holes in the patient table [8].…”