Real-time, high-resolution tomography over an extended field-of-view in scattering tissues remains an elusive goal for biomedical imaging. The apparent trade-off between the depth-of-field and lateral resolution in optical imaging degrades the image resolution outside the confocal region in OCT. Although a number of approaches have been utilized to overcome these limitations, many of these techniques are plagued by either high computational complexity or complicated optical setups. ISAM is a computational technique that can yield spatially invariant transverse resolution by resampling the Fourier space of the data. However, a full 3D ISAM reconstruction requires extensive manipulation of volumetric datasets, imposing significant ...

Optical coherence tomography (OCT) has long been used as a diagnostic tool in the field of ophthalmology. The ability to observe microstructural changes in the tissues of the eye has proved very effective in diagnosing ocular disease. However, this technology has yet to be introduced into the primary care office, where indications of disease are first encountered. We have developed a portable, handheld imaging probe for use in the primary care setting and evaluated its tissue site accessibility, ability to observe diseased tissue, and screening capabilities in in vivo human patients, particularly for pathologies related to the eye, ear and ...

High-resolution real-time tomography of scattering tissues is important for many areas of medicine and biology 1 , 2 , 3 , 4 , 5 , 6 . However, the compromise between transverse resolution and depth-of-field, in addition to low sensitivity deep in tissue, continues to impede progress towards cellular-level volumetric tomography. Computed imaging has the potential to solve these long-standing limitations. Interferometric synthetic aperture microscopy 7 , 8 , 9 is a computed imaging technique enabling high-resolution volumetric tomography with spatially invariant resolution. However, its potential for clinical diagnostics remains largely untapped because full volume reconstructions required lengthy post-processing, and the phase-stability requirements have been difficult to satisfy ...

Magnetomotive optical coherence tomography (MM-OCT) is a functional extension of OCT which utilizes magnetically responsive materials that are modulated by an external magnetic field for contrast enhancement and for elastography to assess the structural and viscoelastic properties of the surrounding tissues. Traditionally, magnetomotive contrast relies on the interaction between the displacement of magnetic particles induced by an external magnetic field and the micro-environmental restoring (elastic) force acting on the particles. When the restoring force from a sample containing magnetic particles is weak or non-existent, the MM-OCT signal-to-noise ratio (SNR) can degrade significantly. We have developed a novel solenoid configuration to ...

Background: Partial mastectomy is the most commonly performed procedure for invasive breast cancer and is associated with a reexcision rate commonly ranging from 20% to 40% in the literature. This high rate of reexcision is associated with significant additional cost (estimated over $4,000 per reexcision) and lower quality outcomes. Optical coherence tomography (OCT) is a high-resolution imaging technology that images tissue structure with micron-scale resolution – on the same scale as histopathology. It is similar to ultrasound except it uses near infra-red light waves instead of sound waves to create detailed images several millimeters deep into tissue. Although widely used ...

Researchers at the University of Illinois at Urbana-Champaign have a long history of novel work in the field of OCT and related fields.  This includes the very promising area of computational adaptive optics and related methods that offer the promise of dramatically improved images in a wide variety of settings by performing post-acquisition processing of magnitude and phase data.  Below is a summary of some of their recent work.  Aberrations degrade resolution, contrast, and signal-to-noise ratio in optical microscopy. In optical coherence tomography (OCT), aberrations limit the resolution of diagnostic features, notably in retinal OCT. With optical coherence microscopy, which ...

We present a method for the numerical correction of optical aberrations based on indirect sensing of the scattered wavefront from point-like scatterers (“guide stars”) within a three-dimensional broadband interferometric tomogram. This method enables the correction of high-order monochromatic and chromatic aberrations utilizing guide stars that are revealed after numerical compensation of defocus and low-order aberrations of the optical system. Guide-star-based aberration correction in a silicone phantom with sparse sub-resolution-sized scatterers demonstrates improvement of resolution and signal-to-noise ratio over a large isotome. Results in highly scattering muscle tissue showed improved resolution of fine structure over an extended volume. Guide-star-based computational adaptive ...

Modern caries treatment concepts like caries management by risk assessment—CAMBRA—entail diagnosing early caries lesions in a precavitated stage to make it possible to reverse the caries process with remineralization and bacteria reduction efforts. Newer, sensitive caries diagnostic tools can serve not only for early detection but also for monitoring of caries lesions to confirm the success of prevention and remineralization efforts. This article describes light-based caries diagnostic tools, with emphasis on fluorescence-based techniques, and compares the most common available fluorescence-based tools with a standardized visual caries inspection system—the International Caries Detection and Assessment System (ICDAS II). Fluorescence ...

In this thesis, x-ray imaging is evaluated and compared with optical coherence tomography (OCT). It is shown that each individual modality provides information about a sample through different physical characteristics. The preclinical variant of x-ray imaging is explored in the context of breast cancer detection and diagnosis because their clinical use could be augmented by OCT. After comparing them, each modality showed its specialized usage. Micro-CT is useful in detecting microcalcifications, the most apparent target of the screening mammogram. OCT can be utilized in the specific cases where high resolution is desired and penetration depth does not need to be ...