title: Arterial Stiffness Estimation by Shear Wave Elastography: Validation in Phantoms with Mechanical Testing.
abstract: Arterial stiffness is an independent risk factor found to correlate with a wide range of cardiovascular diseases. It has been suggested that shear wave elastography (SWE) can be used to quantitatively measure local arterial shear modulus, but an accuracy assessment of the technique for arterial applications has not yet been performed. In this study, the influence of confined geometry on shear modulus estimation, by both group and phase velocity analysis, was assessed, and the accuracy of SWE in comparison with mechanical testing was measured in nine pressurized arterial phantoms. The results indicated that group velocity with an infinite medium assumption estimated shear modulus values incorrectly in comparison with mechanical testing in arterial phantoms (6.7 ± 0.0 kPa from group velocity and 30.5 ± 0.4 kPa from mechanical testing). To the contrary, SWE measurements based on phase velocity analysis (30.6 ± 3.2 kPa) were in good agreement with mechanical testing, with a relative error between the two techniques of 8.8 ± 6.0% in the shear modulus range evaluated (40-100 kPa). SWE by phase velocity analysis was validated to accurately measure stiffness in arterial phantoms.
authors.affiliation: Department of Medical Engineering, School of Technology and Health, KTH Royal Institute of Technology, Stockholm, Sweden; Department of Molecular Medicine and Surgery, Karolinska Institutet, Solna, Sweden. Electronic address: elira.maksuti@sth.kth.se.
authors.forename: Elira
authors.initials: E
authors.lastname: Maksuti
authors.affiliation: Department of Medical Engineering, School of Technology and Health, KTH Royal Institute of Technology, Stockholm, Sweden; Department of Molecular Medicine and Surgery, Karolinska Institutet, Solna, Sweden.
authors.forename: Erik
authors.initials: E
authors.lastname: Widman
authors.affiliation: Department of Medical Engineering, School of Technology and Health, KTH Royal Institute of Technology, Stockholm, Sweden.
authors.forename: David
authors.initials: D
authors.lastname: Larsson
authors.affiliation: Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine, Rochester, Minnesota, USA.
authors.forename: Matthew W
authors.initials: MW
authors.lastname: Urban
authors.affiliation: Department of Medical Engineering, School of Technology and Health, KTH Royal Institute of Technology, Stockholm, Sweden; Department of Molecular Medicine and Surgery, Karolinska Institutet, Solna, Sweden.
authors.forename: Matilda
authors.initials: M
authors.lastname: Larsson
authors.affiliation: Department of Medical Engineering, School of Technology and Health, KTH Royal Institute of Technology, Stockholm, Sweden; Department of Molecular Medicine and Surgery, Karolinska Institutet, Solna, Sweden.
authors.forename: Anna
authors.initials: A
authors.lastname: Bjällmark
mesh_terms: D055119:Elastic Modulus; D054459:Elasticity Imaging Techniques / Q000295:instrumentation*; D007090:Image Interpretation, Computer-Assisted; D019047:Phantoms, Imaging; D015203:Reproducibility of Results; D033081:Shear Strength; D059289:Vascular Stiffness
keywords: Accuracy; Arterial phantom; Arterial stiffness; Group velocity; Lamb waves; Mechanical testing; Phase velocity; Poly(vinyl alcohol); Shear modulus; Shear wave elastography