April...if you are defining percent diameter stenosis using B-Mode
(image) measurements (vs. Doppler criteria) Bluth et al used:
[1-(residual lumen diameter / vessel lumen diameter) X 100]
Vessel lumen diameter was the intima-to-intima measurement of the
vessel lumen diameter (of the vessel being analyzed), and, Residual
lumen diameter was the corresponding measurement of the narrowest
section of the vessel in question. Vessel measurements were made in
the transverse plane. He also described a percent AREA stenosis
Both of these can be referenced in:
"Carotid duplex sonography: A multicenter recommendation for
standardized imaging and Doppler criteria". RadioGraphics,
Volume 8, #3, May 1988.
Your question, however, appears to be directed to the angiography
methodologies utilized by the North American Symptomatic Carotid
Endarterectomy Trail (NASCET) and the European Carotid Surgery
Trialists' Collaborative Group (ECST).
The NASCET trail used the same equation as stated above, however, the
residual lumen is referenced against the distal, normal diameter of
the cervical ICA.
In contrast, the ECST trail referenced the residual lumen against the
nearest normal ICA lumen--closest to the residual lumen.
Both NASCET and ECST trails measured % stenosis in the longitudinal
What may be most important to you, is how your interventional
radiology department measures percent stenosis. It has been my
experience that vessels with < 50% stenosis are typically referenced
against the distal, normal ICA. However, > 50% stenoses are more
often referenced against the ICA closest to the stenosis.
So, if you want an apples to apples comparison (to your B-Mode
measurements)...1) standardize your ultrasonographic method of
measuring stenosis, and, 2) review / monitor your angiographic
correlation's (best done by remeasuring yourself or with your medical
FYI...interestingly, Bluth et al indicated that when there was
disagreement between image and Doppler data for determining percent
stenosis, image data should be relied upon when the peak systolic
velocity (ICA/CCA) ratio was less than 1.8, which is those stenoses
between 1 to 59%.
Rather long winded, but I hope it helps.
______________________________ Reply Separator
Subject: Bluth's criteria for ICA stenosis
Author: "april stinnett" [SMTP:[log in to unmask]] at PHS
Date: 5/28/99 6:55 PM
If anyone is currently using Bluth,Marich and Baker's criteria for percent
stenosis,could you please tell me how they have defined the percent
stenosis.Is it proximal ICA to the distal ICA?Proximal ICA to the BULB? Or
Proximal ICA to the estimated diameter of the lumen?
I appreciate your reply.