MRA Evidence of Superior Sagittal Sinus — Torcular Herophili Divisions in a New Type of Occipital Sinus

Abstract

We describe a new type of occipital sinus: absence (or hypoplasy) of the right transverse sinus, patent right sigmoid sinus and a well formed left occipital sinus draining into the left marginal sinus. The lateral and occipital sinus variations were classified into five groups by Kalbag. This classification was modified in 1980 by Dora and Zileli. We speculate on the possible MRA evidence of "divisions" of the superior sagittal sinus (SSS), as reported by Shao et Al (2009) who examined the lumen of the SSS and torcular Herophili with the aid of an endoscope.