title: Detection of aortic arch calcification in apolipoprotein E-null mice using carbon nanotube-based micro-CT system.
abstract: BACKGROUND
  We performed in vivo micro-computed tomography (micro-CT) imaging using a novel carbon nanotube (CNT)-based x-ray source to detect calcification in the aortic arch of apolipoprotein E (apoE)-null mice.
  
  
  RESULTS
  We measured calcification volume of aortic arch plaques using CNT-based micro-CT in 16- to 18-month-old males on 129S6/SvEvTac and C57BL/6J genetic backgrounds (129-apoE KO and B6-apoE KO). Cardiac and respiratory gated images were acquired in each mouse under anesthesia. Images obtained using a CNT micro-CT had less motion blur and better spatial resolution for aortic calcification than those using conventional micro-CT, evaluated by edge sharpness (slope of the normalized attenuation units, 1.6±0.3 versus 0.8±0.2) and contrast-to-noise ratio of the calcifications (118±34 versus 10±2); both P<0.05, n=6. Calcification volume in the arch inner curvature was 4 times bigger in the 129-apoE KO than in the B6-apoE KO mice (0.90±0.18 versus 0.22±0.10 mm(3), P<0.01, n=7 and 5, respectively), whereas plaque areas in the inner curvature measured in dissected aorta were only twice as great in the 129-apoE KO than in the B6-apoE KO mice (6.1±0.6 versus 3.7±0.4 mm(2), P<0.05). Consistent with this, histological calcification area in the plaques was significantly higher in the 129-apoE KO than in the B6-apoE KO mice (16.9±2.0 versus 9.6±0.8%, P<0.05, 3 animals for each).
  
  
  CONCLUSIONS
  A novel CNT-based micro-CT is a useful tool to evaluate vascular calcifications in living mice. Quantification from acquired images suggests higher susceptibility to calcification of the aortic arch plaques in 129-apoE KO than in B6-apoE KO mice.
authors.affiliation: Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7510, USA.
authors.forename: John M S
authors.initials: JM
authors.lastname: Wait
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Tomita
authors.forename: Laurel M
authors.initials: LM
authors.lastname: Burk
authors.forename: Jianping
authors.initials: J
authors.lastname: Lu
authors.forename: Otto Z
authors.initials: OZ
authors.lastname: Zhou
authors.forename: Nobuyo
authors.initials: N
authors.lastname: Maeda
authors.forename: Yueh Z
authors.initials: YZ
authors.lastname: Lee
mesh_terms: D000818:Animals; D001013:Aorta, Thoracic / Q000000981:diagnostic imaging* / Q000473:pathology; D001018:Aortic Diseases / Q000000981:diagnostic imaging* / Q000209:etiology / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D001027:Aortography / Q000295:instrumentation* / Q000379:methods; D001057:Apolipoproteins E / Q000172:deficiency* / Q000235:genetics; D050197:Atherosclerosis / Q000000981:diagnostic imaging* / Q000209:etiology / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D004195:Disease Models, Animal; D004867:Equipment Design; D005240:Feasibility Studies; D008297:Male; D051379:Mice; D057507:Mice, 129 Strain; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D037742:Nanotubes, Carbon; D058226:Plaque, Atherosclerotic; D011237:Predictive Value of Tests; D015898:Tomography Scanners, X-Ray Computed; D061205:Vascular Calcification / Q000000981:diagnostic imaging* / Q000209:etiology / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D055114:X-Ray Microtomography / Q000295:instrumentation*
chemical_list: D001057:Apolipoproteins E; D037742:Nanotubes, Carbon