title: Flat-panel versus 64-channel computed tomography for in vivo quantitative characterization of aortic atherosclerotic plaques.
abstract: BACKGROUND
  Flat-panel computed tomography (FpCT) provides better spatial resolution than 64-channel CT (64-CT) and may improve in vivo quantitative assessment of atherosclerotic plaques.
  
  
  RESULTS
  Lesions in 184 aortic histology sections from 6 Watanabe heritable hyperlipidemic rabbits were quantitatively compared with 64-CT (image thickness, 0.625 mm) and FpCT (image thickness, 0.150 mm) images. Images were re-oriented perpendicular to the vessel centerline. For detecting plaque, FpCT and 64-CT were not significantly different (sensitivity, 76% vs 66%; P=NS). Although FpCT was significantly more sensitive (42% vs 0%; P=<0.001) for detecting eccentric lesions, the area under the curve (AUC) for FpCT (0.6) was not significantly different from that for 64-CT (0.45; P=NS). In detecting plaques with ≤ 10% lipid (low attenuation foci), FpCT was significantly more sensitive than 64-CT (24% vs 0.7%; P<0.00) and had a significantly greater AUC (0.6 vs 0.5; P<0.006). Additionally, FpCT was more sensitive (65% vs 0%; P<0.00) in detecting plaques with ≤ 5% calcium (high attenuation foci) but not in detecting branch points. Both FpCT and histology allowed us to detect low-attenuation foci as small as 0.3mm in diameter, whereas 64-CT allowed us to detect only low-attenuation foci ≥ 1.5mm in diameter.
  
  
  CONCLUSIONS
  Flat-panel CT seemed to have more potential for quantitatively screening low-risk small atherosclerotic lesions, whereas 64-CT was apparently more useful when imaging established, well-characterized lesions, particularly when measuring the vascular wall thickness in a rabbit model of atherosclerosis.
authors.affiliation: Texas Heart Institute at St. Luke's Episcopal Hospital, Houston, TX, United States. IAboshady@heart.thi.tmc.edu
authors.forename: Ibrahim
authors.initials: I
authors.lastname: Aboshady
authors.forename: Dianna D
authors.initials: DD
authors.lastname: Cody
authors.forename: Evan M
authors.initials: EM
authors.lastname: Johnson
authors.forename: Amir
authors.initials: A
authors.lastname: Gahremanpour
authors.forename: Deborah
authors.initials: D
authors.lastname: Vela
authors.forename: Kamal G
authors.initials: KG
authors.lastname: Khalil
authors.forename: Herbert L
authors.initials: HL
authors.lastname: Dupont
authors.forename: James T
authors.initials: JT
authors.lastname: Willerson
authors.forename: L Maximilian
authors.initials: LM
authors.lastname: Buja
authors.forename: Gregory W
authors.initials: GW
authors.lastname: Gladish
mesh_terms: D000818:Animals; D001011:Aorta / Q000473:pathology; D001027:Aortography / Q000379:methods / Q000592:standards*; D006949:Hyperlipidemias / Q000150:complications / Q000000981:diagnostic imaging; D058226:Plaque, Atherosclerotic / Q000000981:diagnostic imaging* / Q000209:etiology; D011817:Rabbits; D014057:Tomography, X-Ray Computed / Q000379:methods / Q000592:standards*; D014963:X-Ray Intensifying Screens / Q000592:standards*