title: Vascular intramural strain imaging using arterial pressure equalization.
abstract: Peripheral vascular strain imaging has limited strain dynamic range because arterial wall deformations only exhibit small strains under physiologic pressures. A noninvasive freehand ultrasound (US) scanning procedure was performed to apply external force, comparable to the force generated in measuring a subject's blood pressure, to achieve higher strains by equalizing the internal arterial baseline pressure. When the applied pressure matched the internal baseline diastolic pressure, intramural strain and strain rate increased by a factor of 10 over a cardiac cycle. Radial arterial strain was assessed within the vessel wall over the entire deformation procedure using a phase-sensitive 2-D speckle-tracking algorithm. The feasibility of this technique to assess vascular nonlinear elastic properties is demonstrated in an ex vivo experiment and further supported by in vivo measurements. With some uncertainty associated with the elastic properties of surrounding tissue, an elastic modulus reconstruction procedure was developed to estimate the nonlinear elastic properties of the vascular wall.
authors.affiliation: Department of Biomedical Engineering, University of Michigan, Ann Arbor, 48109-2099, USA. kangkim@umich.edu
authors.forename: Kang
authors.initials: K
authors.lastname: Kim
authors.forename: W F
authors.initials: WF
authors.lastname: Weitzel
authors.forename: J M
authors.initials: JM
authors.lastname: Rubin
authors.forename: Hua
authors.initials: H
authors.lastname: Xie
authors.forename: Xunchang
authors.initials: X
authors.lastname: Chen
authors.forename: M
authors.initials: M
authors.lastname: O'Donnell
mesh_terms: D000328:Adult; D000465:Algorithms; D000818:Animals; D001158:Arteries / Q000000981:diagnostic imaging* / Q000502:physiology*; D001794:Blood Pressure / Q000502:physiology; D002417:Cattle; D004548:Elasticity; D006801:Humans; D008297:Male; D008875:Middle Aged; D011673:Pulsatile Flow / Q000502:physiology; D017534:Radial Artery / Q000000981:diagnostic imaging / Q000502:physiology; D013314:Stress, Mechanical; D014463:Ultrasonography