Mineral volume and morphology in carotid plaque specimens using high-resolution MRI and CT.
OBJECTIVE
High-resolution MRI methods have been used to evaluate carotid artery atherosclerotic plaque content. The purpose of this study was to assess the performance of high-resolution MRI in evaluation of the quantity and pattern of mineral deposition in carotid endarterectomy (CEA) specimens, with quantitative micro-CT as the gold standard.


RESULTS
High-resolution MRI and CT were compared in 20 CEA specimens. Linear regression comparing mineral volumes generated from CT (VCT) and MRI (VMRI) data demonstrated good correlation using simple thresholding (VMRI=-0.01+0.98VCT; R2=0.90; threshold=4xnoise) and k-means clustering methods (VMRI=-0.005+1.38VCT; R2=0.93). Bone mineral density (BMD) and bone mineral content (BMC [mineral mass]) were calculated for CT data and BMC verified with ash weight. Patterns of mineralization like particles, granules, and sheets were more clearly depicted on CT.


CONCLUSIONS
Mineral volumes generated from MRI or CT data were highly correlated. CT provided a more detailed depiction of mineralization patterns and provided BMD and BMC in addition to mineral volume. The extent of mineralization as well as the morphology may ultimately be useful in assessing plaque stability.
Wolf
Ronald L
RL
Department of Radiology, University of Pennsylvania Medical Center, 3400 Spruce St, Philadelphia, PA 19104, USA. Ronald.Wolf@uphs.upenn.edu
Wehrli
Suzanne L
SL
Popescu
Andra M
AM
Woo
John H
JH
Song
Hee Kwon
HK
Wright
Alexander C
AC
Mohler
Emile R
ER
Harding
John D
JD
Zager
Eric L
EL
Fairman
Ronald M
RM
Golden
Michael A
MA
Velazquez
Omaida C
OC
Carpenter
Jeffrey P
JP
Wehrli
Felix W
FW
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002340:Carotid Artery Diseases / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000473:pathology*; D005069:Evaluation Studies as Topic; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods* / Q000592:standards; D008297:Male; D008875:Middle Aged; D008903:Minerals / Q000378:metabolism*; D015203:Reproducibility of Results; D014057:Tomography, X-Ray Computed / Q000379:methods* / Q000592:standards
D008903:Minerals