Detection of internal carotid artery stenosis: comparison of MR angiography, color Doppler sonography, and arteriography.

Abstract

Findings of two-dimensional time-of-flight magnetic resonance (MR) angiography projection angiograms were prospectively compared with those of color Doppler sonography by using angiography as a standard in 23 consecutive patients (42 carotid bifurcations) to evaluate their utility in determining the presence of carotid artery stenosis. MR angiography helped detect 50% or greater lumen diameter stenosis (sensitivity, 0.96; specificity, 0.64). Color Doppler sonography with 1.25 m/sec peak systolic velocity as a threshold had a sensitivity of 0.96 and a specificity of 0.71. Statistical analysis showed a correlation between percentage of lumen diameter narrowing and the length of the zone of signal intensity loss with MR angiography (r = .69; P less than .0001). A stronger relationship was obtained between angiographic narrowing and peak systolic velocity derived from color Doppler sonography (r = .80; P less than .0001). Two-dimensional time-of-flight MR angiography displayed as projection angiograms and combined with carotid artery and combined with carotid artery sonography is a useful approach for helping detect and potentially grade the severity of stenoses of the carotid artery.

Internal carotid artery stenosis: comparison of duplex scan and magnetic resonance angiography with digital subtraction angiography

“…DS was associated with better results, as previously described 14,18,22 . The most important task of the diagnostic tests evaluated here is to determine which should be referred to endarterectomy.…”

“…In this case in which there was a severe ipsilateral stenosis of the external carotid artery -both A B DS and MRA misdiagnosed IC sub-occlusion and DGA correctly showed its occlusion. Some authors indicate endarterectomy only with DS, as this procedure shows a better correlation with DGA than MRA 14,18,22 . Nevertheless, MRA shows anatomic information that can be helpful to the surgeon and is not available in DS studies.…”

“…Also, there is some error related to DGA, as shown when inter-observer concordance is assessed [14][15][16] . The present study compares two non-invasive procedures to DGA, attempting to reduce the risks and costs attributed to DGA, as other authors have done before 14,[16][17][18][19][20][21][22][23] .…”

“…Some studies on this issue divide IC stenosis in categories, from simple dicotomization 22 to five categories 18 . There is also a report distinguishing only occlusion and sub-occlusion 16 .…”

“…There is no agreement about the accuracy of non-invasive methods in the various studies. Some showed bad results 16,18,20,23 , while others obtained good correlation with only limited restrictions, mainly in cases of IC sub-occlusion or when DS and MRA disagree 14,17,19,21,22 .…”