Ability to Use Duplex US to Quantify Internal Carotid Arterial Stenoses: Fact or Fiction?1
Edward G. Grant, MD,
André J. Duerinckx, MD, PhD,
Suzie M. El Saden, MD,
Michelle L. Melany, MD,
Gasser M. Hathout, MD,
Peter T. Zimmerman, MD,
Alan K. Marumoto, MD,
Stanley N. Cohen, MD and
J. Dennis Baker, MD
1 From the Departments of Radiology (E.G.G., A.J.D., S.M.E.S., M.L.M., G.M.H., P.T.Z., A.K.M.), Neurology (S.N.C.), and Surgery (J.D.B.), West Los Angeles Veterans Affairs Medical Center, 11301 Wilshire Blvd, Los Angeles, CA 90073. Received November 25, 1998; revision requested January 18, 1999; revision received April 8; accepted June 28. Address reprint requests to E.G.G. (e-mail: egrant@ucla.edu).
View larger version (43K):
[in a new window]
|
Figure 2a. Histograms display distribution of PSVs (in centimeters per second) in ICAs (carotids) grouped into (a) 10% incremental classifications of stenosis; (b) three broad categories; and (c) two categories, at least and less than 70% stenosis. In a and b, while differentiation may be possible between categories at extreme ends of the spectrum, moderate degrees of stenosis have velocities spread widely across other categories. In c, while some overlap persists, most patients with less than 70% stenoses have PSVs on the left side of the histogram that are less than those in patients with greater than or equal to 70% stenosis. By using a threshold of 225 cm/sec, a peak accuracy of 90.6% can be achieved.
|
|
View larger version (39K):
[in a new window]
|
Figure 2b. Histograms display distribution of PSVs (in centimeters per second) in ICAs (carotids) grouped into (a) 10% incremental classifications of stenosis; (b) three broad categories; and (c) two categories, at least and less than 70% stenosis. In a and b, while differentiation may be possible between categories at extreme ends of the spectrum, moderate degrees of stenosis have velocities spread widely across other categories. In c, while some overlap persists, most patients with less than 70% stenoses have PSVs on the left side of the histogram that are less than those in patients with greater than or equal to 70% stenosis. By using a threshold of 225 cm/sec, a peak accuracy of 90.6% can be achieved.
|
|
View larger version (26K):
[in a new window]
|
Figure 2c. Histograms display distribution of PSVs (in centimeters per second) in ICAs (carotids) grouped into (a) 10% incremental classifications of stenosis; (b) three broad categories; and (c) two categories, at least and less than 70% stenosis. In a and b, while differentiation may be possible between categories at extreme ends of the spectrum, moderate degrees of stenosis have velocities spread widely across other categories. In c, while some overlap persists, most patients with less than 70% stenoses have PSVs on the left side of the histogram that are less than those in patients with greater than or equal to 70% stenosis. By using a threshold of 225 cm/sec, a peak accuracy of 90.6% can be achieved.
|
|
Copyright © 2000 by the Radiological Society of North America.
) and the percentage of stenosis and (b) the mean VICA/VCCA (
) and the percentage of stenosis measured arteriographically. The PSV and VICA/VCCA increase with the increasing severity of stenosis. Error bars show 1 SD about the mean. Note the overlap in adjacent categories of stenosis.