Reproducibility of fibrous cap status assessment of carotid artery plaques by contrast-enhanced MRI.
OBJECTIVE
Reproducibility in identifying the fibrous cap (FC) of carotid artery plaques by noncontrast-enhanced MRI has been shown to be poor. The objective of this study was to assess the reproducibility of multisequence MRI, including contrast-enhanced images, in assessing FC status.


METHODS
Forty-five symptomatic patients with 30% to 69% carotid artery stenosis underwent a multisequence MRI protocol, which included contrast-enhanced images. FC status (ie, discrimination between fibrotic and/or calcified plaques, plaques with a lipid-rich necrotic core and an intact and thick FC, and plaques with a lipid-rich necrotic core and a thin and/or ruptured FC) was independently assessed by 3 observers of which one also scored all images on a different occasion. Linear weighted kappa coefficients (kappa) were calculated as indicators of inter- and intraobserver agreement.


RESULTS
On a per-slice basis, interobserver agreement was good (kappa=0.60, 0.64, and 0.71), whereas intraobserver agreement was very good (kappa=0.86). On a per-plaque basis, interobserver agreement was good (kappa=0.64, 0.69, and 0.78), whereas intraobserver agreement was very good (kappa=0.96).


CONCLUSIONS
This study found good interobserver and very good intraobserver agreement in assessing FC status of carotid artery plaques. Future studies are warranted to determine the predictive value of FC status assessment by multisequence MRI, including contrast-enhanced images, on the occurrence of (recurrent) cerebral ischemic events.
Kwee
Robert M
RM
Department of Radiology, Maastricht University Medical Center, Maastricht, The Netherlands. rmkwee@gmail.com
van Engelshoven
Jos M A
JM
Mess
Werner H
WH
ter Berg
Johannes W M
JW
Schreuder
Floris H B M
FH
Franke
Cees L
CL
Korten
Arthur G G C
AG
Meems
Bé J
BJ
van Oostenbrugge
Robert J
RJ
Wildberger
Joachim E
JE
Kooi
Marianne E
ME
D000368:Aged; D000369:Aged, 80 and over; D002114:Calcinosis / Q000000981:diagnostic imaging*; D002339:Carotid Arteries / Q000000981:diagnostic imaging*; D016893:Carotid Stenosis / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D011859:Radiography; D015203:Reproducibility of Results