Medical Imaging Physics: Quantitative imaging and analysis of the pediatric spinal cord to detect pathologies.*

Diffusion Tensor Imaging (DTI) is a magnetic resonance imaging technique, based on water diffusion in tissue. Using Einstein’s equation of diffusion and the Bloch equation, we can obtain quantitative diffusion indices, such as fractional anisotropy (FA), mean diffusivity (MD), radial diffusivity (RD), and axial diffusivity (AD). We analyzed DTI data from pediatric patients at Vanderbilt Children’s Hospital to quantitatively evaluate the health of the spinal cord. We obtained DTI from 17 pediatric patients, aged 1 to 16 (mean: 7 years, SD: 4 years). Thirteen patients were identified as normal, and four patients were diagnosed with neurological disorders, including Chiari I, tethered cord, and an intra-spinal tumor. We hypothesize that quantitative diffusion indices could assist existing clinical MRI in the diagnosis and prognosis of some pathologies of the cord. We believe that our new data analysis can produce indices that may be able to differentiate between healthy spinal cord and disease. In the presentation, we will review the physics and mathematical concepts utilized in DTI. Then, we will explain how we process the images to obtain DTI metrics. Finally, we will discuss our results, and how they may be potential clinical biomarkers.