TY - JOUR
T1 - Identification of cholesteryl esters in human carotid atherosclerosis by ex vivo image-guided proton MRS
AU - Ruberg, Frederick L.
AU - Viereck, Jason
AU - Phinikaridou, Alkystis
AU - Qiao, Ye
AU - Loscalzo, Joseph
AU - Hamilton, James A.
PY - 2006/2
Y1 - 2006/2
N2 - Vulnerable atherosclerotic plaques may be identified by their large lipid component, particularly liquid cholesteryl ester (CE), covered by a fibrous cap. We hypothesized that image-guided 1H proton magnetic resonance spectroscopy (MRS) would identify mobile CE in discrete, preselected regions of atherosclerotic plaque. Human carotid endarterectomy specimens (n = 10) were imaged ex vivo by magnetic resonance imaging (MRI) at high field (11.7 T) utilizing standard T1- and T2-weighted spin echo protocols. MRS spectra were acquired from 1 mm3 voxels, localized to plaque regions that we judged by MRI to be lipid rich or lipid poor. The spectra revealed methyl and methylene resonances of fatty acyl chains with relative intensities and linewidths characteristic of pure CE, by comparison with lipid standards. Regions judged to be lipid rich by MRI showed much more intense CE resonances than did lipid-poor regions. The integrated intensities of lipid peaks were 5.5 ± 2.0% (lipid-rich regions) versus 0.9 ± 0.6% (lipid-poor regions) of the unsuppressed water peak (P < 0.0001). Lipid distribution by histology, MRS, and MRI showed strong correlation.jlr Image-guided proton MRS accurately identified CE in selected regions of atherosclerotic plaque as small as 1 mm3 in an ex vivo setting. This procedure may permit the noninvasive detection and quantification of CE in atherosclerotic plaque in vivo.
AB - Vulnerable atherosclerotic plaques may be identified by their large lipid component, particularly liquid cholesteryl ester (CE), covered by a fibrous cap. We hypothesized that image-guided 1H proton magnetic resonance spectroscopy (MRS) would identify mobile CE in discrete, preselected regions of atherosclerotic plaque. Human carotid endarterectomy specimens (n = 10) were imaged ex vivo by magnetic resonance imaging (MRI) at high field (11.7 T) utilizing standard T1- and T2-weighted spin echo protocols. MRS spectra were acquired from 1 mm3 voxels, localized to plaque regions that we judged by MRI to be lipid rich or lipid poor. The spectra revealed methyl and methylene resonances of fatty acyl chains with relative intensities and linewidths characteristic of pure CE, by comparison with lipid standards. Regions judged to be lipid rich by MRI showed much more intense CE resonances than did lipid-poor regions. The integrated intensities of lipid peaks were 5.5 ± 2.0% (lipid-rich regions) versus 0.9 ± 0.6% (lipid-poor regions) of the unsuppressed water peak (P < 0.0001). Lipid distribution by histology, MRS, and MRI showed strong correlation.jlr Image-guided proton MRS accurately identified CE in selected regions of atherosclerotic plaque as small as 1 mm3 in an ex vivo setting. This procedure may permit the noninvasive detection and quantification of CE in atherosclerotic plaque in vivo.
KW - Magnetic resonance spectroscopy
KW - Plaque lipids
KW - Stroke
KW - Vulnerable plaque
UR - http://www.scopus.com/inward/record.url?scp=33244481493&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=33244481493&partnerID=8YFLogxK
U2 - 10.1194/jlr.M500431-JLR200
DO - 10.1194/jlr.M500431-JLR200
M3 - Article
C2 - 16317172
AN - SCOPUS:33244481493
SN - 0022-2275
VL - 47
SP - 310
EP - 317
JO - Journal of Lipid Research
JF - Journal of Lipid Research
IS - 2
ER -