Prostate cancer (PCa) is the most common non-cutaneous malignancy in men. Men suspected with PCa are then offered transrectal ultrasound (TRUS) guided prostate biopsies to confirm the diagnosis, which falls short of making a reliable differentiation between cancer and benign hyperplasia of the gland. Suspected cancerous lesions tend to be stiffer (or harder to feel) than benign tissue. Various elastography modalities such as Ultrasound elastography and MRI elastography are known to have poor spatial resolution, which limits their ability to differentiate small lesions and in identifying early and subtle changes. OCT is an optical imaging technique that enables high-resolution, cross-sectional ...

Investigating the elasticity of ocular tissue (cornea and intraocular lens) could help the understanding and management of pathologies related to biomechanical deficiency. In previous studies, we introduced a setup based on optical coherence tomography for shear wave elastography (SWE) with high resolution and high sensitivity. SWE determines tissue stiffness from the propagation speed of shear waves launched within tissue. We proposed acoustic radiation force to remotely induce shear waves by focusing an ultrasound (US) beam in tissue, similar to several elastography techniques. Minimizing the maximum US pressure is essential in ophthalmology for safety reasons. For this purpose, we propose a ...

We present first quantitative three-dimensional (3D) data sets recorded using optical coherence elastography (OCE) for the diagnosis and detection of prostate cancer (PCa). 120 transrectal ultrasound guided prostate biopsy specimens from 10 men suspected with prostate cancer were imaged using OCE. 3D quantitative mechanical assessment of biopsy specimens obtained in kilopascals (kPa) at an interval of 40 µm was compared with histopathology. Sensitivity, specificity, and positive and negative predictive values were calculated for OCE in comparison to histopathology. The results show OCE imaging could reliably differentiate between benign prostate tissue, acinar atypical hyperplasia, prostatic intraepithelial neoplasia and malignant PCa. The ...

The aqueous outflow system (AOS) is responsible for maintaining normal intraocular pressure (IOP) in the eye. Structures of the AOS have an active role in regulating IOP in healthy eyes and these structures become abnormal in the eyes with glaucoma. We describe a newly developed system platform to obtain high-resolution images of the AOS structures. By incorporating spectral domain optical coherence tomography (SD-OCT), the platform allows us to systematically control, image, and quantitate the responses of AOS tissue to pressure with a millisecond resolution of pulsed flow. We use SD-OCT to image radial limbal segments from the surface of the ...

We combined phase-sensitive optical coherence tomography (PhS-OCT) and acoustic radiation force (ARF) to develop a shear wave elastography (SWE) method that could be used for ophthalmic applications. SWE measures tissue stiffness from the speed of shear waves propagating through tissue. Assessing the elastic properties of the cornea and the intraocular lens can, for example, help the management of refractive surgeries (myopia or presbyopia correction). OCT is a non-contact imaging method easily applicable in vivo that provides micron-scale resolution particularly suitable for characterizing ocular tissues. ARF is commonly used to remotely induce shear waves in tissue by emitting short (∼100 µs ...

Assessing the biomechanical properties of the cornea can provide clinically valuable information in addition to structural images for better management of pathologies (e.g. glaucoma) or refractive surgeries. OCT provides a micron scale and high sensitivity that are ideal for ophthalmic applications. We propose a shear wave elastography (SWE) method for the cornea based on phase-sensitive optical coherence tomography (PhS-OCT). SWE consists in launching a propagating shear wave in tissues and retrieving tissue elasticity from the shear wave speed. We used a piezo-electric actuator in contact with the cornea to induce shear waves that were then tracked using a PhSOCT ...

Optical coherence tomography (OCT) based microangiography is capable of visualizing 3D functional blood vessel networks within microcirculatory tissue beds in vivo. To provide the quantitative information of vasculature from the microangiograms such as vessel diameter and morphology, it is necessary to develop efficient vessel segmentation algorithms. In this paper, we propose to develop a hybrid Hessian/intensity based method to segment and quantify shape and diameter of the blood vessels innervating capillary beds that are imaged by functional OCT in vivo. The proposed method utilizes multi-scale Hessian filters to segment tubular structures such as blood vessels, but compounded by the ...