title: MRI of rabbit atherosclerosis in response to dietary cholesterol lowering.
abstract: Direct imaging of the atherosclerotic plaque, rather than the angiographic lumen, may provide greater insight into the response of atherosclerosis to cholesterol-lowering therapy. Aortic plaque was studied in vivo by MRI in rabbits undergoing dietary cholesterol intervention. Thirty-one rabbits underwent aortic balloon injury and high-cholesterol diet for 4 months and then were assigned to low-cholesterol versus continued high-cholesterol diet for up to an additional 16 months. High-resolution (310 micrometer) fast spin-echo MRI of the abdominal aorta was performed at 4, 12, and 20 months and compared with histology. MRI demonstrated a significant reduction in % area stenosis in rabbits placed on low-cholesterol diet (44.6+/-2. 1% at 20 months versus 55.8+/-1.5% at 4 months, P=0.0002). In contrast, % area stenosis increased in rabbits maintained on high-cholesterol diet (69.8+/-3.8% at 20 months versus 55.8+/-1.5% at 4 months, P=0.001). Similarly, plaque thickness decreased significantly in the low-cholesterol group (0.60+/-0.05 mm at 20 months versus 0.85+/-0.06 mm at 4 months, P=0.006), with a trend toward increase in the high-cholesterol group (1.02+/-0.08 mm at 20 months versus 0.85+/-0.06 mm at 4 months, P=0.1). Thus, in rabbits undergoing dietary cholesterol lowering, MRI detected regression of aortic atherosclerotic plaque in vivo. Plaque progression was seen with maintenance of high-cholesterol diet. MRI is a promising noninvasive technology for directly imaging atherosclerosis and its response to therapeutic interventions.
authors.affiliation: Noninvasive Laboratory, Vascular Medicine, Atherosclerosis Unit, Brigham and Women's Hospital, Boston, MA 02115, USA. mcconnell@stanford.edu
authors.forename: M V
authors.initials: MV
authors.lastname: McConnell
authors.forename: M
authors.initials: M
authors.lastname: Aikawa
authors.forename: S E
authors.initials: SE
authors.lastname: Maier
authors.forename: P
authors.initials: P
authors.lastname: Ganz
authors.forename: P
authors.initials: P
authors.lastname: Libby
authors.forename: R T
authors.initials: RT
authors.lastname: Lee
mesh_terms: D000818:Animals; D001012:Aorta, Abdominal / Q000473:pathology; D001161:Arteriosclerosis / Q000175:diagnosis* / Q000473:pathology; D002784:Cholesterol / Q000097:blood; D002791:Cholesterol, Dietary / Q000008:administration & dosage*; D008279:Magnetic Resonance Imaging; D008297:Male; D011817:Rabbits; D015203:Reproducibility of Results
chemical_list: D002791:Cholesterol, Dietary; D002784:Cholesterol