title: In vivo evidence of porcine cornea anisotropy using supersonic shear wave imaging.
abstract: OBJECTIVE
  This work proposes shear wave elastography to quantify the elastic anisotropy of the cornea.
  
  
  METHODS
  Experiments were conducted on enucleated porcine eyeballs and anesthetized swine. We used the supersonic shear wave imaging (SSI) method implemented on a dedicated 15-MHz rotating linear ultrasound array. This setup allows determining the shear wave speed variations for a set of radial propagation directions.
  
  
  RESULTS
  All the results showed a local anisotropy with one main direction of maximal stiffness. The influence of pulsatility was observed in vivo, and electrocardiogram (ECG) gating was consequently performed for all anesthetized swine. On ex vivo corneas, n = 27 acquisitions were performed in the limbus region, where the collagen fibrils are reported to run tangentially to the sclera. A good match was shown between the direction of maximal stiffness and the expected direction of the collagen fibrils.
  
  
  CONCLUSIONS
  This preliminary study demonstrates the potential of SSI for the assessment of corneal anisotropy in both ex vivo and in vivo conditions.
authors.affiliation: Ecole Supérieure de Physique et Chimie Industrielles (ESPCI ParisTech), Paris-Sciences-Lettres Research University (PSL), Institut Langevin, Paris, France.
authors.forename: Thu-Mai
authors.initials: TM
authors.lastname: Nguyen
authors.affiliation: Ecole Supérieure de Physique et Chimie Industrielles (ESPCI ParisTech), Paris-Sciences-Lettres Research University (PSL), Institut Langevin, Paris, France.
authors.forename: Jean-Francois
authors.initials: JF
authors.lastname: Aubry
authors.affiliation: Ecole Supérieure de Physique et Chimie Industrielles (ESPCI ParisTech), Paris-Sciences-Lettres Research University (PSL), Institut Langevin, Paris, France.
authors.forename: Mathias
authors.initials: M
authors.lastname: Fink
authors.affiliation: Supersonic Imagine, Aix-en-Provence, France.
authors.forename: Jeremy
authors.initials: J
authors.lastname: Bercoff
authors.affiliation: Ecole Supérieure de Physique et Chimie Industrielles (ESPCI ParisTech), Paris-Sciences-Lettres Research University (PSL), Institut Langevin, Paris, France.
authors.forename: Mickael
authors.initials: M
authors.lastname: Tanter
mesh_terms: D000818:Animals; D016880:Anisotropy; D003315:Cornea / Q000000981:diagnostic imaging / Q000502:physiology*; D003952:Diagnostic Imaging / Q000379:methods*; D004548:Elasticity; D054459:Elasticity Imaging Techniques; D008027:Light; D013552:Swine
keywords: cornea; elastic anisotropy; shear wave elastography; ultrasound