Shear wave pulse compression for dynamic elastography using phase-sensitive optical coherence tomography.
Assessing the biomechanical properties of soft tissue provides clinically valuable information to supplement conventional structural imaging. In the previous studies, we introduced a dynamic elastography technique based on phase-sensitive optical coherence tomography (PhS-OCT) to characterize submillimetric structures such as skin layers or ocular tissues. Here, we propose to implement a pulse compression technique for shear wave elastography. We performed shear wave pulse compression in tissue-mimicking phantoms. Using a mechanical actuator to generate broadband frequency-modulated vibrations (1 to 5 kHz), induced displacements were detected at an equivalent frame rate of 47 kHz using a PhS-OCT. The recorded signal was digitally compressed to a broadband pulse. Stiffness maps were then reconstructed from spatially localized estimates of the local shear wave speed. We demonstrate that a simple pulse compression scheme can increase shear wave detection signal-to-noise ratio (>12  dB gain) and reduce artifacts in reconstructing stiffness maps of heterogeneous media.
University of Washington, Department of Bioengineering, 3720 15th Avenue NE, Seattle, Washington 98195.
Thu-Mai
TM
Nguyen
University of Washington, Department of Bioengineering, 3720 15th Avenue NE, Seattle, Washington 98195bUniversity of Dundee, School of Engineering, Physics and Mathematics, Scotland, United Kingdom.
Shaozhen
S
Song
University of Washington, Department of Bioengineering, 3720 15th Avenue NE, Seattle, Washington 98195.
Bastien
B
Arnal
University of Washington, Department of Bioengineering, 3720 15th Avenue NE, Seattle, Washington 98195.
Emily Y
EY
Wong
University of Dundee, School of Engineering, Physics and Mathematics, Scotland, United Kingdom.
Zhihong
Z
Huang
University of Washington, Department of Bioengineering, 3720 15th Avenue NE, Seattle, Washington 98195cUniversity of Washington, Department of Ophthalmology, 325 9th Avenue, Seattle, Washington 98104.
Ruikang K
RK
Wang
University of Washington, Department of Bioengineering, 3720 15th Avenue NE, Seattle, Washington 98195.
Matthew
M
O'Donnell
D000362:Agar / Q000737:chemistry; D001696:Biomechanical Phenomena; D054459:Elasticity Imaging Techniques / Q000379:methods*; D004867:Equipment Design; D006801:Humans; D008863:Microspheres; D019047:Phantoms, Imaging; D033081:Shear Strength; D059629:Signal-To-Noise Ratio; D012867:Skin / Q000473:pathology; D013314:Stress, Mechanical; D013997:Time Factors; D041623:Tomography, Optical Coherence / Q000379:methods*
D000362:Agar