So now just a word about structural morphology.
Structural morphology is essentially a refinement of the volumetric technique.
It is possible of course that the volume of a particular structure does not change
between a patient and a control population.
But the shape changes either over time or
between groups in a way that does not effect the overall volume.
So if the shape changes you could possibly detect without being able to detect any
volume differences.
So, structural morphology is an analysis method to compare shape
differences between groups of subjects or shape over time.
On the left-hand side, you see an example of shape differences between two groups.
At the top, you see the extent or the magnitude of the displacement or
the magnitude of the change.
And on the bottom is indicated in these different colors of purple, red, and
green whether or not the deflection or
the change is inward, outward, or the areas where there are no differences.
So here you can imagine a situation where the overall volume doesn't change because
in certain areas you have inward deflections and
other areas have outward deflections that overall cancel each other out.
But they're certainly shape changes that happened between subject groups
that may be relevant to the symptomatology that these patients or
these subjects are displaying.
On the right-hand side I'm showing an example of longitudinal morphometry.
So you could look over longitudinal period of time if there are shape changes to
a particular structure that could be relevant.
In this particular case,
we're dealing with patients with early Alzheimer's disease.
And if you look, the red colors indicate significant shape changes over time.
So, this is 0, 6, 12, 18, and 24, month scans.
And the red indicates the earliest change.
And you'll see the red progressing from the bottom left-hand side to the top right
side showing a very clear shaped pattern of changes overtime that could have very
significant implications for the behavior that these patients or
the impairments that these patients are showing.
And this is an example of the shape change in the entorhinal cortex specifically
in patients with early Alzheimer's disease.