Diffusion MRI basic questions

Hello all,

I am a newbie and I have some basic doubts.

  1. What is ex vivo diffusion MRI ?

  2. Why do we use imaging phantoms for capturing dMRI images and how efficient will it be for implementing tractography algorithms?

Acquiring DWI brain scans of living organisms is tricky. Surrounding tissue like bone and air sinuses hamper the field. homogeneity. Blood flow, respiration and head movement impact the image. Scan times are limited as humans find it hard stay still for long periods and animal anesthesia is hard to prolong.

To summarize this article in vivo DWI is limited by, for example, physiological noise and low signal-to-noise ratio. Therefore, ex vivo allows verification and validation of postprocessing and analysis methods are lacking. Additionally, ex vivo imaging can help identify features that would be impossible to detect in vivo.

Phantoms do not suffer the physiological artifacts of living animals. They can be designed to have good homogeneity. There is a known ground truth.This allows one to objectively identify the best methods.


Hi Chris. Thanks for the reply.