An important concept is this: whenever the brain swells, it
means the gyri get larger and the sulci get smaller as illustrated
As in Fig. the sulci and gyri may not be obvious because
of either swelling or compactness as in most young people. However,
it is very important to appreciate that the whole brain surface
is made of sulci and gyri, which is easier to appreciate in
Figs. . ‘All the gyri and sulci of the brain are named.
Some of the CSF spaces are larger (big sulci) and more constant
(present in every scan) and easily identified; therefore they are
used as the compass for navigating the maze of sulci on the surface
of the brain . Can you name some of them?’
Occasionally the presence of air (dark spots in Fig.) in
the sulci allows us to appreciate easily that the homogenouslooking
appearance of the CT scan (Fig. ) actually consists
of sulci and gyri.