Shiguetomi Medina, Juan Manuel3; Stødkilde-Jørgensen, Hans4; Rahbek, Ole3; Møller-Madsen, Bjarne3
1 Department of Clinical Medicine - The Department of Orthopaedics E, ?AS, Department of Clinical Medicine, Health, Aarhus University2 Department of Clinical Medicine - The MR Research Centre, Department of Clinical Medicine, Health, Aarhus University3 Department of Clinical Medicine - The Department of Orthopaedics E, ?AS, Department of Clinical Medicine, Health, Aarhus University4 Department of Clinical Medicine - The MR Research Centre, Department of Clinical Medicine, Health, Aarhus University
Introduction Magnetic Resonance imaging (MRI) can be used for studies of joint cartilage as well as bone growth plates. A number of MR derived parameters present aspects of viability and growth patterns: the apparent diffusion constant (ADC) is dependent on intracellular as well as extracellular water movements and as such related to cell viability and cell apoptosis. The ADC provides early signs of ischemic lesions; diffusion tensor images provide information on structure of the tissue and finally measurements of water concentration identifies the areas with highest osteoblast activity. Methods Four normal pig frozen tibiae were studied. Tomography, MR T1 and T2 sequences were performed and compared. Apparent Diffusion Coefficient and Surface Tension Images were also performed and analyzed. Finally, methylmethacrylate embedding histology was performed using hematoxylin-eosin, toluidine blue and safranin stains. Results MR ADC and Surface Tension Images are able to provide an overview of the cell metabolism measuring the movement and freedom of the water in the different tissues. These measurements can be interpretated as flow and metabolism respectively. Bony structures seen in high resolution MR images resemble those seen in histological sections. Discussion A number of MR derived sequences can be applied to cartilage-like tissue such as growth plate. These sequences provide images that correspond to flow and cell-metabolism. MR imaging provides enough evidence and information about the structure and behavior of the growth plate to propose a standardized protocol for MRI ADC and Tension Surface Images. This should provide more information about growth disturbances causes and characteristics. MR Apparent Diffusion Constant and Surface Tension Images can provide an overview of the cell metabolism and flow of the bone growth plate. This is a new application for specialized MR sequences.