April 2017 – Tractography

Three-dimensional fiber tract reconstruction (Tractography) based on Diffusion Tensor Imaging (DTI) is becoming a widely-used tool to study and visualize human white matter (nerve pathways) anatomy. T1 and T2 data sets from MRI studies are used to visualize Optic Radiations (transmit visual information to the visual cortex for interpretation) and Corticospinal Tracts (transmit sensory/motor information to the Medulla Oblongata). These tracts form a critical component of the visual pathway and their visualization aids neurosurgery in the lateral temporal, inferior parietal, and occipital lobes, thereby protecting the structures vital for visual integrity. Their accurate delineation aids clinicians in avoiding interruption of the pathways during tumor removal and epilepsy surgeries, as well as speech alterations.

To accomplish this, intricate Regions of Interest (ROI) schemes were devised to include and exclude white matter tracts in both hemispheres of the brain.

To demonstrate the Corticospinal Motor fibers, ROIs encompass from the Pre-Central Gyrus, to the Anterior Central Sulcus inclusive (Image 1A-B below left). The Optic Radiations are produced from ROIs drawn (Images 1 (C-D)to encompass the ventricles from atria to apices. The other areas demonstrated are the SLF (Superior Longitudinal Fasciculus) which includes the Arcuate fasciculus, and the Uncinate Fasciculus.

The Stanford 3D Technologist utilized advanced 3D software to create Volume Rendered (VR) Fiber Tracts, curved planar reformations (CPRs) and cross-sectional Images from MRI datasets to demonstrate the nerve pathways of interest, which provides detailed diagnostic information to the physicians to aid in their course of treatment.