Authors: Zishu Zhang Marja Berg Aki Ikonen Mervi Könönen Reetta Kälviäinen Hannu Manninen Ritva Vanninen
Publish Date: 2005/06/14
Volume: 15, Issue: 11, Pages: 2359-2365
Abstract
The aim of this study was to investigate CT angiography CTA luminal area measurements in the assessment of carotid artery stenosis compared with the current clinically used criteria based on lumen diameter measurements Seventytwo vessels in 36 patients were evaluated by CTA and digital subtraction angiography DSA Two observers measured area and diameter stenosis degrees using automated 3D CTA analysis software The ratio of the largest/smallest luminal diameter at the level of maximal stenosis L/S ratio was used to describe lumen morphology Diagnostic agreement between CTA and DSA was calculated For the assessment of area stenosis interobserver and intraobserver correlation coefficients were 0898 and 0906 p0001 The correlation coefficient between the diameter stenosis and area stenosis was lower in stenoses with extremely noncircular lumen L/S ratio ≥15 r=0797 p0001 compared with stenoses with circular lumen LS ratio 12 r=0978 p0001 Only satisfactory agreement κ 054077 p0001 was obtained between area stenosis on CTA and diameter stenosis on DSA Assessment of stenosis degree with area measurements on 3D CTA proved to be reproducible Area stenosis provides a lesssevere estimate of the degree of carotid stenosis but might theoretically express the real hemodynamic significance of the lesion better than diameter stenosis especially in stenoses with noncircular lumenThe equation A=2NN2 is valid when carotid lumens are circular in shape L/S ratio=10 both at the level of maximal stenosis and at the level of reference Thus for 70 50 and 30 diameter stenosis the corresponding area stenosis values are 91 75 and 51 respectively
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