Just had to jump in here. Clearly, the point was made that you need
     to use spectral analysis as the primary classification tool. To
     whatever school of thought you subscribe, it is imperative that you
     VERIFY your results, not blindly follow someone else's. Meticulous
     attention and CONSISTENCY is the more important than 50 vs 60
     degrees. I measure the residual lumen routinely but use it
     primarily to confirm the spectral data category. If there is
     disagreement, we call it an image/Doppler mismatch, then one needs
     to look a little more closely, take a few more images, ask why?
     Understand the original velocity data identified stenosis in the
     bulb, hence all the recent "new" criteria for grading the important
     cutoffs. I also believe it is inherently wrong to lessen our
     accuracy or at least our description of what is there (ie: call a
     50% lesion in the bulb normal because the residual lumen is reduced
     to that of the distal ICA?) in order to correlate with an imperfect
     gold standard that will be gone in a few years anyway. Mostly, I
     agree with Kirk's reply. If you could look at the raw data of the
     duplex results in the NASCET trials, throw out residual lumen
     measurements and/or categories and look solely at velocities, I
     believe you would find an obvious break between symptomatic and
     asymptomatic individuals. Go with the flow! (Sorry I couldn't
     resist!)

     Bill Schroedter
     Venice,FL.


______________________________ Reply Separator _________________________________
Subject: Carotid stenosis.
Author:  UVM Flownet <[log in to unmask]> at Internet
Date:    9/3/99 11:16 PM


        Hello Flownetters,

I would like to request some advice on the evaluation of carotid stenosis.
In our Hospital we measure stenosis by ultrasound comparing the diameter of the
lumen with the diameter of the vessel at the point of maximum stenosis (real ste
nosis), but correlation  with the results of arteriography is sometimes poor bec
ause they compare the diameter of the lumen with the distal diameter of the caro
tid.
Do you think that we must do the same by ultrasound?

Carlos Nicolau