title: Liposome-enhanced MRI of neointimal lesions in the ApoE-KO mouse.
abstract: Conventional high-resolution MRI is capable of detecting lipid-rich atherosclerotic plaques in both human atherosclerosis and animal models of atherosclerosis. In this study we induced neointimal lesions in ApoE-KO mice by placing a constrictive collar around the right carotid artery. The model was imaged with conventional multispectral MRI, and the thickened wall could not be distinguished from surrounding tissue. We then tested paramagnetic liposomes (mean size=90 nm) for their ability to improve MRI visualization of induced thickening, using Gd-DTPA as a control. T1-weighted (T1-w), black-blood MRI of the neck area of the mice was performed before and 15 min, 45 min, and 24 hr after intravenous injection of either paramagnetic liposomes or Gd-DTPA. The collared vessel wall of mice that were injected with liposomes showed a pronounced signal enhancement of approximately 100% immediately after injection, which was sustained largely until 24 hr postinjection. In contrast, the vessel wall of all controls (left carotid artery and animals injected with Gd-DTPA) did not show significant contrast enhancement at those time points. This study demonstrates that intimal thickening in ApoE-KO mice can be effectively detected by contrast-enhanced (CE)-MRI upon injection of paramagnetic liposomes.
authors.affiliation: Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands.
authors.forename: Willem J M
authors.initials: WJ
authors.lastname: Mulder
authors.forename: Kim
authors.initials: K
authors.lastname: Douma
authors.forename: Gerben A
authors.initials: GA
authors.lastname: Koning
authors.forename: Marc A
authors.initials: MA
authors.lastname: van Zandvoort
authors.forename: Esther
authors.initials: E
authors.lastname: Lutgens
authors.forename: Mat J
authors.initials: MJ
authors.lastname: Daemen
authors.forename: Klaas
authors.initials: K
authors.lastname: Nicolay
authors.forename: Gustav J
authors.initials: GJ
authors.lastname: Strijkers
mesh_terms: D000818:Animals; D001057:Apolipoproteins E / Q000172:deficiency*; D002340:Carotid Artery Diseases / Q000175:diagnosis*; D003287:Contrast Media; D004195:Disease Models, Animal; D004337:Drug Carriers / Q000737:chemistry*; D019786:Gadolinium DTPA / Q000008:administration & dosage* / Q000737:chemistry; D007089:Image Enhancement / Q000379:methods*; D008081:Liposomes / Q000737:chemistry*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D051379:Mice; D018345:Mice, Knockout; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D017539:Tunica Intima / Q000473:pathology
chemical_list: D001057:Apolipoproteins E; D003287:Contrast Media; D004337:Drug Carriers; D008081:Liposomes; D019786:Gadolinium DTPA