What is diffusion sequence MRI?

What is diffusion sequence MRI?

Diffusion-weighted magnetic resonance imaging (DWI or DW-MRI) is the use of specific MRI sequences as well as software that generates images from the resulting data that uses the diffusion of water molecules to generate contrast in MR images.

How does Diffusion MRI work?

In diffusion MRI, magnetic field gradients are employed to sensitize the image to diffusion in a particular direction. The direction is different for each image, resulting in a different pattern of signal loss (dark areas) due to anisotropic diffusion.

What is diffusion sequence?

Diffusion sequences are actually T2 weighted sequences, sensitized to diffusion by gradients. The contrast of the diffusion image will have both a diffusion and a T2 component, which must be taken into consideration in the interpretation.

What is a diffusion gradient MRI?

A diffusion-weighted image is the unprocessed result of the application of a single pulsed gradient SE sequence in one gradient direction, and it corresponds to one point in q-space. Even though such an image is rather simple, it does contain some information about diffusion.

What are the different MRI sequences?

The most common MRI sequences are T1-weighted and T2-weighted scans. T1-weighted images are produced by using short TE and TR times. The contrast and brightness of the image are predominately determined by T1 properties of tissue. Conversely, T2-weighted images are produced by using longer TE and TR times.

What diffusion restricts on MRI?

Many pathologies cause restricted extracellular diffusion of water protons including infarction, cytotoxic edema, high cellularity within tissue, viscous fluid, demyelination, and metabolic disturbances.

How is DTI performed?

The DTI tractography is performed in an MRI scanner, which is a large tube surrounded by a circular magnet that creates a magnetic field around you. You will lie on a table that slides into the MRI scanner. DTI tractography images rely on your ability to be still in order to create clear images.

What is T1 and T2 and T2 * on MRI?