I should clarify that stenotic group does not just include those with narrow caliber, or where the measured area of signal is below a certain threshold. It also includes those who may have missing jugular(s), or even abnormally closed jugular(s) in which no signal is generated on contrast-enhanced venography, or time-of-flight venography. Those cases would be considered stenotic. Using MR we have shown ~70% stenotic/anomalous in two sets of data of MS patients in papers. And 55-60% with another paper using similar criteria. Granted, we have our own criteria for stenosis classification, but we have consistent results and there is striking similarity between the normals flow and non-stenotic group flow. It would be very interesting to take stenotic cases classified with catheter venography and compute flow using MR with them to see if the results are similar! And I wonder what explanation can be given to the non-stenotic MS subset with similar total flow and normalized flow to our healthy controls.
Are you going to be at the Sherbrooke conference this weekend? I am eager to present and discuss our latest findings with you. I will have to read up on the Trabbaloussee research in the meanwhile.