Intravascular MR imaging of atherosclerotic plaque: ex vivo analysis of human femoral arteries with histologic correlation.
OBJECTIVE
To assess the potential role of intravascular magnetic resonance (MR) imaging with receiver coils mounted to an inflatable balloon in characterizing atherosclerotic plaque.


METHODS
Twelve human harvested segmental femoral arteries with atherosclerotic changes were studied with a 5-F imaging balloon catheter equipped with a single-loop wire receiver coil. Imaging was performed with an open-configuration 0.5-T (n = 6) or a 1.5-T (n = 6) MR system, with T1- and T2-weighted sequences. Histologic analysis was the reference standard, and MR images were analyzed with regard to vessel wall thickness, plaque area, and components.


RESULTS
Images acquired at 1.5 T were characterized by better in-plane resolution (117 x 104 microm). Resolution at 0.5 T (234 x 178 microm) was sufficient to discriminate the wall layers. On T2-weighted images, adventitia, media, and thickened intima could be discriminated. T1-weighted images did not permit differentiation between wall layers. There was good correlation between MR and histologic measurements of wall thickness (r = .97) and plaque area (r = .98). Plaque characterization was possible on T2-weighted images. Calcified plaque was identified as areas of low signal intensity (134 +/- 98) and could be differentiated from fibrous structures containing collagen (1,968 +/- 680) or fatty components (762 +/- 394).


CONCLUSIONS
Intravascular MR imaging on the basis of the balloon catheter design enables differentiation of wall layers and plaque components.
Zimmermann
G G
GG
Department of Diagnostic Radiology, University Hospital Zurich, Switzerland.
Erhart
P
P
Schneider
J
J
von Schulthess
G K
GK
Schmidt
M
M
Debatin
J F
JF
D000368:Aged; D000369:Aged, 80 and over; D001161:Arteriosclerosis / Q000175:diagnosis* / Q000473:pathology; D002404:Catheterization / Q000295:instrumentation; D005263:Femoral Artery / Q000473:pathology*; D006801:Humans; D066298:In Vitro Techniques; D018810:Magnetic Resonance Angiography / Q000295:instrumentation; D008875:Middle Aged