[Puddleglum]

How come the sinuses show in the second scan but not the first? Could be comparing apples and oranges?

[DelphiUser]

>>How come the sinuses show in the second scan but not the first?

My Sinus does not extend into my brain, I hope :-)

[AntiGuv]

Beats me, so here's a normal brain with sinuses:

[AntiGuv]

PS. Actually, that above scan indicates a tumor, so it's not a "normal" brain, but it's still in far better shape than Schiavo's was! (and it shows sinuses of course..)

[Polybius]

How come the sinuses show in the second scan but not the first? Could be comparing apples and oranges?

Yes. See Post 94.

They compared third ventricle axial level apples with fourth ventricle axial level oranges.

The frontal para-nasal sinuses, however, are a red herring. Frontal sinuses vary in every individual and are sometimes huge and sometimes congenitally absent. Whether you see them or not at a certain axial level is therefore of little significance as an anatomical landmark.