title: Elasticity imaging of atheroma with transcutaneous ultrasound: preliminary study.
abstract: BACKGROUND
  Knowledge of the physical properties of atherosclerotic plaque is essential when evaluating its vulnerability in a clinical setting. Such knowledge, however, is still difficult to obtain with the various approaches developed to date.
  
  
  RESULTS
  This article describes a noninvasive method for evaluating the regional elasticity (the elastic modulus in the circumferential direction) of tissue surrounding atherosclerotic plaque in which a novel phased tracking method is applied to measure minute changes in thickness of each of the multiple layers of the arterial wall during one heartbeat. By comparing the pathological findings with the distribution of elasticity, average elasticity of lipid and that of a mixture of smooth muscle and collagen fiber can be determined. On the basis of these reference parameters, each point is statistically categorized as lipid, mixture, or other. Thus, the plaque is electronically stained using transcutaneous ultrasound. By applying the method to the common carotid arteries, the presence of thin collagen fiber was clarified along the arterial axis for normal subjects, whereas soft inclusion of lipid was found for every plaque in subjects with hyperlipidemia.
  
  
  CONCLUSIONS
  This novel method offers potential as a diagnostic technique for detection of plaque vulnerability with high spatial resolution.
authors.affiliation: Department of Electronic Engineering, Graduate School of Engineering, Tohoku University, Sendai 980-8579, Japan. hkanai@ecei.tohoku.ac.jp
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kanai
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Hasegawa
authors.forename: Masataka
authors.initials: M
authors.lastname: Ichiki
authors.forename: Fumiaki
authors.initials: F
authors.lastname: Tezuka
authors.forename: Yoshiro
authors.initials: Y
authors.lastname: Koiwa
mesh_terms: D000328:Adult; D000368:Aged; D001161:Arteriosclerosis / Q000150:complications / Q000000981:diagnostic imaging* / Q000473:pathology; D017536:Carotid Artery, Common / Q000000981:diagnostic imaging; D003094:Collagen / Q000032:analysis; D004548:Elasticity; D006801:Humans; D006949:Hyperlipidemias / Q000150:complications; D007083:Iliac Artery / Q000000981:diagnostic imaging / Q000473:pathology; D008055:Lipids / Q000032:analysis; D008297:Male; D008955:Models, Cardiovascular; D009131:Muscle, Smooth, Vascular / Q000000981:diagnostic imaging; D011237:Predictive Value of Tests; D012016:Reference Values; D015203:Reproducibility of Results; D014463:Ultrasonography / Q000379:methods*; D014654:Vascular Patency
chemical_list: D008055:Lipids; D003094:Collagen