Structural changes

Brain structural alterations are investigated by using magnetic resonance imaging and other structural imaging techniques, and by assessing structural changes in bodily features. Click on the tabs below, or navigate the topics via the section on the left.
Image: ©efks – Fotolia – stock.adobe.com

Diffusion tensor imaging

What is DTI? Diffusion tensor imaging (DTI) is a specialised imaging technique that uses MRI technology to investigate the movement of water within tissues of interest. By applying a magnetic field, the movement (“diffusivity”) of water molecules can be visualised in vivo. The diffusion of water is influenced by the cellular structure of the surrounding tissues, and measures such as fractional anisotropy (FA) were derived as an approximate measurement for the freedom of movement. In areas of high structural coherence such as white matter, FA is highest, indicating that water is moving in relatively fixed directions. It is lower in…

MRI

What is MRI? The technology of structural magnetic resonance imaging (MRI) is based on the magnetisation properties of cellular protons. The application of a strong magnetic field causes the protons within cells to shift direction, which will return to their original position over time (“precession”). The rate of precession differs across tissue types (such as grey matter and white matter in the brain), which can be interpreted by specialised programs to represent a 3D image. What is the evidence for changes in brain volume in people with PTSD? Moderate quality evidence found small to medium-sized reductions in total brain volume,…

Telomere length

What are telomeres? Telomeres are protective caps on the ends of chromosomes. They are linked to aging as they shorten with each cell division, and when they reach a critical length, the cell stops dividing or dies. Chronic stress has been associated with reduced telomere length, resulting in the recognition of an association between adverse social and environmental influences and accelerated aging. What is the evidence for changes in telomere length in people with PTSD? Moderate to high quality evidence found a small effect of shorter telomere length in people with PTSD compared to controls. August 2021 Image: ©freshidea –…

NeuRA Libraries

Title Colour Legend:
Green - Topic summary is available.
Orange - Topic summary is being compiled.
Red - Topic summary has no current systematic review available.