MR Diffusion Anisotropy Imaging of Spinal Cord Mechanical Compression and Injury on the Rat Model. In Vivo

The aim of this study was the application of magnetic resonance diffusion anisotropy imaging (MR DAI) for assessment of spinal cord compression (SCC) and injury (SCI) in rats depending on the time course from the moment of injury. Twenty rats were used, divided into three groups (five with no surgical operation, five with laminectomy only and ten with SCI produced using a dynamic weight - drop model). MR DAI was performed four times (1, 24, 48 and 168 hours after surgery) at 4.7 T with diffusion gradients applied parallel and perpendicular to the spine. Diffusion parameters (lADC, tADC and AI) were calculated for defined regions of white and gray matter. Epidural hematoma which appeared after laminectomy compressed spinal cord and caused a decrease of apparent diffusion coefficient (ADC) values in GM and WM. SCI in WM produced a decrease of lADC and increase in tADC. In GM an increase in both lADC and tADC values after SCI was observed. MR DAI will disclose dynamic changes in water diffusion during the first days after spinal cord contusion.