Brain venous study: the role of TCCD

The use of ultrasound to study cerebral venous circulation is a very recent application of transcranial color coded Doppler sonography (TCCD). Several authors have attempted to use trancranial Doppler (TCD), which is a pulsed blind method, but in this area (the study of venous circulation) TCD reveals all its limitations. The insonation takes place in a blind manner and failure to detect the vessel can readily lead to misinterpretation. Whereas, through compressive tests (whose safety and utility is still debated), we are able to obtain useful information from arterial studies, in venous studies these tests cannot be performed – we absolutely have to “see” the vessel and/or venous sinus in order be completely certain of their insonation. To detect correct peak systolic velocity (PSV) and peak end diastolic velocity (PEDV) values, guided correction is indispensable because a correct angle can change the values enormously (in the venous context, where velocimetric parameters are basically very low, angle correction is vitally important). But this correction is possible only if we can detect the vessel and its direction for about a centimetre at least. Moreover, bi-dimensional imaging is irreplaceable in the search for important reference points (protuberantia occipitalis interna, falx cerebri, tentorium etc.) which, in turn, help us to find suitable insonation planes in which to look for the venous vessels themselves (1,2). Several structures can be insonated. They include: • the deep middle cerebral vein (DMCV) • the vein of Rosenthal (RV) • the vein of Galen (GV) • the sphenoparietal sinus (SPaS) • the superior sagittal sinus (SSS) (distal part) • the straight sinus (SRS) • the superior petrosal sinus (SPS) • the inferior petrosal sinus (IPS) • the transverse sinus (TS) • the sigmoid sinus (SS) • the basal venous plexus (BPV)