Magnetic resonance plaque imaging to predict the occurrence of the slow-flow phenomenon in carotid artery stenting procedures.
BACKGROUND
The purpose is to investigate the feasibility of magnetic resonance (MR) plaque imaging in predicting the arterial flow impairment (slow-flow phenomenon) during carotid artery stenting (CAS) using a filter-type protection device.


METHODS
Thirty-one carotid artery stenotic lesions in 30 patients (28 men and two women; mean age, 71.8 years) were evaluated by MR plaque imaging with black blood T1- and T2-weighted and time-of-flight sequences before CAS. Main plaque components were classified as vulnerable (intraplaque hemorrhage and lipid-rich/necrotic core) or stable (fibrous tissue and dense calcification) from the signal pattern. The plaque classification was statistically compared with the occurrence of slow-flow phenomenon.


RESULTS
The slow-flow phenomenon was observed in ten CAS procedures (five flow arrests and five flow reductions). Flow arrests consisted of four vulnerable and one stable plaque, and flow reductions consisted of four vulnerable and one stable plaque. The slow-flow phenomenon occurred significantly (P<0.01) more frequently in patients with vulnerable plaque.


CONCLUSIONS
Vulnerable carotid plaques have a significantly higher risk of slow-flow phenomenon than stable plaques. The occurrence of the slow-flow phenomenon can be predicted by MR plaque imaging before CAS.
Sakamoto
Masahiko
M
Department of Radiology, Nara Medical University, 840 Shijo-cho, Kashihara, Nara 634-8522, Japan. masakamoto5@yahoo.co.jp
Taoka
Toshiaki
T
Nakagawa
Hiroyuki
H
Takayama
Katsutoshi
K
Wada
Takeshi
T
Myouchin
Kaoru
K
Akashi
Toshiaki
T
Miyasaka
Toshiteru
T
Fukusumi
Akio
A
Iwasaki
Satoru
S
Kichikawa
Kimihiko
K
D000368:Aged; D000369:Aged, 80 and over; D002339:Carotid Arteries / Q000473:pathology*; D016893:Carotid Stenosis / Q000473:pathology / Q000503:physiopathology* / Q000628:therapy*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D018810:Magnetic Resonance Angiography; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D012039:Regional Blood Flow; D012189:Retrospective Studies; D012306:Risk; D015607:Stents / Q000009:adverse effects*