MRI of early- and late-stage arterial remodeling in a low-level cholesterol-fed rabbit model of atherosclerosis.
OBJECTIVE
To monitor early- and late-stage arterial remodeling following low-level cholesterol (CH) feeding in rabbits using a standardized MRI protocol.


METHODS
New Zealand White rabbits were fed a CH diet (0.25% w/w) (n = 15) or normal chow (n = 6) and imaged either at 0, 2, 6, 8, and 11 months ("early-stage") or 12, 14, 16, 18, and 20 months ("late-stage"). T2-weighted fast-spin-echo images ( approximately 200 microm in-plane resolution) of aortic lesions were collected using either a 1.5 or 3.0T MR scanner interfaced with a customized surface RF coil. Luminal (LA), outer vessel wall boundary (OVBA), and vessel wall areas (VWA) were assessed.


RESULTS
Among CH-fed animals in the early-stage group, increased VWA associated with decreased OVBA and a more pronounced decrease in LA was first detectable at 8 months. These changes became more evident between 8 and 11 months. In the late-stage group, lesions continued to grow in response to CH-feeding, as VWA significantly increased at regular 2-month intervals. Beyond 16 months, signal intensity differences (reflecting increased lesion complexity) within the vessel wall were noted.


CONCLUSIONS
This often-overlooked rabbit model combined with customized MR technology holds tremendous promise for studying the natural progression, regression, and remodeling of atherosclerotic lesions.
Ronald
John A
JA
Department of Medical Biophysics, University of Western Ontario, London, ON, Canada.
Walcarius
Rhonda
R
Robinson
John F
JF
Hegele
Robert A
RA
Rutt
Brian K
BK
Rogers
Kem A
KA
D000821:Animal Feed; D000818:Animals; D001158:Arteries / Q000473:pathology*; D050197:Atherosclerosis / Q000175:diagnosis* / Q000473:pathology*; D002784:Cholesterol / Q000378:metabolism*; D002791:Cholesterol, Dietary / Q000378:metabolism*; D004867:Equipment Design; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D011817:Rabbits; D013997:Time Factors
D002791:Cholesterol, Dietary; D002784:Cholesterol