Internal carotid arterial stenosis: CT angiography with volume rendering.
OBJECTIVE
To determine the reliability of helical computed tomography (CT) with volume rendering for evaluation of internal carotid arterial stenosis.


METHODS
In 22 patients, 44 carotid arteries were evaluated with helical CT and selective conventional angiography. CT data were displayed on volume-rendered and maximum intensity projection (MIP) images. Stenoses were measured separately on axial, volume-rendered, and MIP images and on conventional angiograms. Each artery was then graded as having no stenosis, mild (< 30%) stenosis, moderate (30%-70%) stenosis, severe (> 70%) stenosis, near occlusion, or occlusion.


RESULTS
One case of stenosis was not assessable at axial CT because of an inappropriate scanning plane; four cases were not assessable at MIP CT because of mural calcifications. All carotid arteries were assessable on volume-rendered images despite no depiction of the residual lumen at the site of narrowing in three cases of near occlusion. Correlations between angiography and helical CT were good. Axial, volume-rendered, and MIP images enabled correct classification of stenosis in 88%, 89%, and 90% of arteries, respectively. CT with volume rendering was slightly more sensitive for determining candidates for endarterectomy (i.e., those with > 70% stenosis and near occlusion); sensitivity was 100% and specificity, 92%.


CONCLUSIONS
CT angiography with volume rendering enabled accurate evaluation of carotid disease, even when dense calcifications were present. However, no definite advantage over currently available techniques for CT measurement of stenosis severity was found.
Leclerc
X
X
Department of Neuroradiology, Hôpital Roger Salengro, Lille, France.
Godefroy
O
O
Lucas
C
C
Benhaim
J F
JF
Michel
T S
TS
Leys
D
D
Pruvo
J P
JP
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000792:Angiography; D001027:Aortography; D001161:Arteriosclerosis / Q000145:classification / Q000000981:diagnostic imaging* / Q000601:surgery; D001766:Blindness / Q000000981:diagnostic imaging; D002545:Brain Ischemia / Q000000981:diagnostic imaging; D002114:Calcinosis / Q000145:classification / Q000000981:diagnostic imaging; D002343:Carotid Artery, Internal / Q000000981:diagnostic imaging* / Q000601:surgery; D016893:Carotid Stenosis / Q000145:classification / Q000000981:diagnostic imaging* / Q000601:surgery; D016894:Endarterectomy, Carotid; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D002546:Ischemic Attack, Transient / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011856:Radiographic Image Enhancement; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed