Fibrous septa in the straight dural sinus

Postmortem exploration of the straight sinus supplemented in some cases by radiography revealed the presence of single or multiple septa or synechiae in the sinus in 44 of 145 cases. A septum should not be mistaken for a thrombus. The septa are of roentgenologic significance because of their ability to alter the appearance of the sinus from one cerebral angiography to another in one and the same patient.