As in “gyral enhancement”. What the hell does it mean? I’ve been googling like hell, and all it turns up is a bunch of MRI analyses.
gy·rus (jrs)
n. pl. gy·ri (-r)
Any of the prominent, rounded, elevated convolutions on the surfaces of the cerebral hemispheres. source
Take that with your results on MRI analyses, and my WAG would be that “gyral enhancement” refers to some imaging technique used to enhance the MRI image of the gyrus in question.
The term is specific to imaging techniques; “enhancement” refers to any increase in the visibility of a structure, which may have a variety of possible causes, including reaction to injected tracer chemicals. Some disease conditions or injuries can be diagnosed by such enhancement.
Just what I needed. johncole, Nametag, thanks. 
In general, scientists use the word “enhancement” to mean “increase in value.” I think it most commonly means “increase in brightness,” but that may just be my field. In any case, it does not carry the connotation of “improvement”.
Yeah, but just try putting “Medical Enhancement” in the title of an e-mail at work.