MRI Diffusion Tensor Imaging (DTI) interpretation:
Locating the corticospinal tract (CST)

Diffusion tensor imaging, or DTI, is an advanced MRI technique in which the asymmetric motion of water is used to map out specific properties in the brain. One application of DTI is called tractography, or identifying the specific tracts of neurons which pass through the brain.

One of the most important fiber tracts in the brain is the corticospinal tract, or CST. This tract connects the motor cortex with the spinal cord, passing through the cerebral peduncles. This fiber tract is important because it is the tract most responsible for voluntary movement. It can be affected by a number of pathologies, such as tumors, cortical malformation, and stroke. For some conditions, such as tumors, it can be critically important to locate the CST before performing surgery, so that the surgeons can properly plan their surgery. That’s where DTI comes in.

In this video, Dr. Michael Hoch demonstrates how to use a two region of interest method to identify the corticospinal tract, first placing a region of interest in the cerebral peduncle and a second in the motor cortex. He also talks about some of the pitfalls of diffusion tensor imaging and what kind of problems to look out for.

The level of this lecture is appropriate for radiology residents, radiology fellows, and trainees in other specialties who have an interest in advanced MRI techniques such as diffusion tensor imaging (DTI) tractography, functional MRI (fMRI), and surgical planning.

For more information, see the whole video playlist on Advanced MRI.