Characterization of coronary atherosclerotic plaque using multicontrast MRI acquired under simulated in vivo conditions.
OBJECTIVE
To compare coronary atherosclerotic plaque characterization using multicontrast MRI on: 1) freshly excised vessels under simulated in vivo conditions, and 2) preserved vessels.


METHODS
T1-weighted (T1W), T2-weighted (T2W), proton density-weighted (PDW), and diffusion-weighted (DW) MR images were acquired on 13 freshly excised human coronary arteries from explanted hearts. Vessels were imaged in an MR-compatible tissue culture chamber using a 4.7 Tesla small-bore MR scanner. Eight vessels were then preserved in buffered formalin and rescanned following the same imaging protocol. A three-dimensional spatially penalized fuzzy C-means (3D-SPFCM) technique was applied to classify different plaque constituents. The classification results from vessels under "fresh" and "preserved" conditions were compared with corresponding histological sections.


RESULTS
For most plaque constituents, the plaque characterization results show no significant difference between fresh and preserved scans, and little difference between scans and the histological reference standard. In the case of thrombus, apparent signal changes between fresh and preserved images were identified. Overall, MR scans conducted under preserved conditions provided a 1.8% to 17.5% greater signal-to-noise ratio (SNR) than those conducted in the fresh stage.


CONCLUSIONS
Preservation of coronary vessels did not alter the contrast between plaque tissues on multicontrast MRI, and did not significantly change the results of plaque constituent characterization.
Sun
Binjian
B
Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30322, USA.
Giddens
Don P
DP
Long
Robert
R
Taylor
W Robert
WR
Weiss
Diana
D
Joseph
Giji
G
Vega
David
D
Oshinski
John N
JN
D003324:Coronary Artery Disease / Q000473:pathology*; D003331:Coronary Vessels / Q000033:anatomy & histology / Q000473:pathology*; D017143:Fuzzy Logic; D006801:Humans; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D066298:In Vitro Techniques; D008279:Magnetic Resonance Imaging / Q000379:methods*