[Extracranial carotid artery disease assessed by contrast enhanced three-dimensional MR angiography: correlation with carotid ultrasonography].
OBJECTIVE
To evaluate the imaging features of extracranial carotid stenosis and to compare the findings with contrast enhanced three-dimensional MR angiography(CE 3D-MRA) with those of carotid ultrasonography(CUS).


METHODS
Both studies were performed in 24 patients(48 carotid arteries) with extracranial carotid arteriosclerotic stenosis. Based on the CUS findings, the degree of stenosis was classified into four grades: normal, mild; 1-39%, moderate; 40-69%, severe; and 70-99%, occlusion. The presence or absence of ulceration, as well as high-grade turbulence (HGT) at the stenotic portion, was also assessed by CUS. Furthermore, according to the findings of CE 3D-MRA, stenosis was again classified into four types: normal(n = 4), narrow(n = 26), signal void(n = 10), and occlusion(n = 8).


RESULTS
Both studies correctly identified occlusion in 8 arteries. Of 19 arteries that were classified as having mild or moderate stenosis on CUS, 16(84%) were narrow on CE 3D-MRA. On the other hand, of 20 arteries classified as showing severe stenosis on CUS, 10(50%) and 10(50%) were classified as the narrow type and signal-void type, respectively, on CE 3D-MRA. Signal void was only seen in the severe stenosis group. Ulceration was detected more frequently in the signal-void type than in the narrow type (7/10 vs. 5/10). In addition, the incidence of HGT in the signal-void type was significantly higher than that in the narrow type(9/10 vs. 3/10: p < 0.02).


CONCLUSIONS
CE 3D-MRA shows the features of extracranial carotid stenosis more reliably than CUS. In addition, signal void detected on CE 3D-MRA may reflect severe carotid stenosis with HGT.
Arai
Syouichi
S
Department of Radiology, Fukuoka University School of Medicine.
Utsunomiya
Hidetsuna
H
Tashiro
Tadashi
T
Kuroiwa
Taizo
T
Okazaki
Masatoshi
M
D000368:Aged; D000369:Aged, 80 and over; D016893:Carotid Stenosis / Q000175:diagnosis* / Q000000981:diagnostic imaging; D005260:Female; D006801:Humans; D018810:Magnetic Resonance Angiography; D008297:Male; D008875:Middle Aged; D014463:Ultrasonography