1 Axial computed tomography (CT) scans of the frontal sinus. A: due to the long lasting pressure of mucus, the bone of the anterior wall of frontal sinus is thinned out and elevated anteriorly, forming a bulge. B: same situation as depicted in fig A: the posterior bony wall of frontal sinus is thinned out and extremely elevated posteriorly towards the frontal lobe of the brain. As depicted on the scan, a thin bony layer covering the dura could be recognized intraoperatively
Kindly provided by Jens Ponikau, Mayo Clinic. Copyright Mayo Foundation 2003.