Abstract
This study discusses the CT findings of pneumosinus dilatans of the sphenoid sinus, highlighting the clinically important CT characteristics. The CT findings of 26 patients with overpneumatization of the sphenoid sinus are presented in correlation with the clinical findings. Twenty-two patients had overpneumatization beyond the boundaries of the body of the sphenoid bone with or without bone remodelling but only two patients reported headaches. Thinning of the bone structures was also present in three patients but only one patient reported headaches. Overpneumatization of the sphenoid sinus with thinning of bunywalls reduced the width of the superior orbital fissure in one patient resulting in a gradual decrease of visual acuity. CT is an accurate method for the evaluation of overpneumatization of the sphenoid sinus due to its high sensitivity in depicting evidence of bone erosion using a bone window as imaging settings.