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The FreeSurfer processing stream is controlled by a shell script called recon-all. [10] The script calls component programs that organize raw MRI images into formats easily usable for morphometric and statistical analysis. FreeSurfer automatically segments the volume and parcellates the surface into standardized regions of interest (ROIs).
For gray matter, this quantity is usually referred to as gray matter density (GMD) or gray matter concentration (GMC), or gray matter probability (GMP). In order to correct for the volume changes due to the registration, the gray matter volume (GMV) in the original brain can be calculated by multiplying the GMD with the Jacobian determinants of ...
Grey matter undergoes development and growth throughout childhood and adolescence. [3] Recent studies using cross-sectional neuroimaging have shown that by around the age of 8 the volume of grey matter begins to decrease. [4] However, the density of grey matter appears to increase as a child develops into early adulthood. [4]
The VBM analysis showed global gray matter was decreased linearly with age, especially for men, whereas global white matter did not decline with age. A key description of the methodology of voxel-based morphometry is Voxel-Based Morphometry—The Methods [ 9 ] —one of the most cited articles in the journal NeuroImage . [ 10 ]
There is a difference between the cerebral blood volume of gray and white matter. The cerebral blood volume value of gray matter is about 3.5 +/- 0.4 ml/100g, and the white matter is about 1.7 +/- 0.4 ml/100g. The gray matter is nearly twice that of white matter. [3] In both white and gray matter, cerebral blood volume decreases by about 0.50% ...
The volume and frequency is strongly associated with increasing age. [2] They are also seen in a number of neurological disorders and psychiatric illnesses . For example, deep white matter hyperintensities are 2.5 to 3 times more likely to occur in bipolar disorder and major depressive disorder than control subjects.
Another possible explanation is that there is an increase in local venous blood volume. In either case, this image suggests that the tissue associated with this vascular territory could be tissue at risk. Future stroke research will involve comparisons of perfusion weighted imaging and SWI to learn more about local flow and oxygen saturation.
The size of the brain is a frequent topic of study within the fields of anatomy, biological anthropology, animal science and evolution.Measuring brain size and cranial capacity is relevant both to humans and other animals, and can be done by weight or volume via MRI scans, by skull volume, or by neuroimaging intelligence testing.