Title :
An elasticity microscope. Part I: Methods
Author :
Cohn, N. Abraham ; Emelianov, Stanislav Y. ; Lubinski, Mark A. ; O´Donnell, M.
Author_Institution :
Dept. of Biomed. Eng., Michigan Univ., Ann Arbor, MI, USA
Abstract :
An elasticity microscope images tissue stiffness at fine resolution. Possible applications include dermatology, ophthalmology, pathology, and tissue engineering. In addition, if the resolution approaches cellular dimensions, then this system may be very useful in understanding tissue micromorphology. Elasticity images can be reconstructed from displacement and strain fields measured throughout the specimen during controlled external loading. High frequency ultrasound is used to obtain these images by tracking coherent speckle motion during deformation. In this paper, methods are presented to track speckle in two dimensions with near unity correlation coefficients using a high frequency, single element focused transducer. These techniques include improved means for speckle tracking. Procedures to control boundary conditions for consistent specimen deformation and scanning techniques required to obtain a plane-strain state in the imaging plane are also discussed. To test these methods, a 50 MHz elasticity microscope was constructed.
Keywords :
acoustic microscopy; biomechanics; biomedical ultrasonics; elasticity; speckle; 50 MHz; boundary condition; coherent speckle motion; correlation coefficient; displacement field; elasticity microscope; high frequency ultrasound imaging; scanning technique; single element focused transducer; specimen deformation; strain field; tissue stiffness; two dimensional tracking; Displacement measurement; Elasticity; Frequency; Image reconstruction; Image resolution; Microscopy; Pathology; Speckle; Strain measurement; Tissue engineering;
Journal_Title :
Ultrasonics, Ferroelectrics, and Frequency Control, IEEE Transactions on
