Radiology, Vol 157, 807-811, Copyright © 1985 by Radiological Society of North America
Videodensitometric quantitation of stenosis: in vitro and in vivo validation
JA Seibert, DP Link, HH Hines and HA Baltaxe
Percentage of stenosis of a vascular lumen was quantitated using a digital
subtraction angiography system with videodensitometric analysis. To
validate the algorithm and methods, we used precisely drilled Lucite rods
of three inner diameters and various reduced diameters to give known
luminal reduction. Both in vitro and in vivo results of stenosis
measurements resulted in an excellent correlation between actual and
measured values (correlation coefficient greater than 0.9 for all trials).
Consistent underestimation of stenosis of about 5% was attributed to the
various image degradations inherent with the imaging procedure and
equipment. Errors were greatest with midrange stenoses and less at the
extremes of the lesion values. An insufficient signal-to-noise ratio was
caused by low photon flux and/or low contrast material concentration and
overlying vasculature filled with contrast material. Overall, the
videodensitometric technique is accurate, easy to implement, objective, and
relatively free of errors associated with the geometric/edge detection
method.
