25 research outputs found
Snapshot spectrally encoded fluorescence imaging through a fiber bundle
Fiber optic endomicroscopy is a valuable tool
for clinical diagnostics and animal studies because it can
capture images of tissue in vivo with subcellular resolution.
Current configurations for endomicroscopes have either
limited spatial resolution or require a scanning mechanism
at the distal end of the fiber, which can slow imaging speed
and increase the probe size. We present a novel configuration
that provides high contrast 350 Ă— 350 pixel images at
7.2 frames per second, without the need for mechanical
scanning at the proximal or distal end of the fiber. The proofof-
concept benchtop system is tested in fluorescence mode
and can resolve 1.5 ÎĽm features of a high resolution 1951
USAF target
Multi-Modal Imaging Techniques for Early Cancer Diagnostics
Cancer kills more Americans under the age of 75 than any other disease. Although most cancers occur in epithelial surfaces that can be directly visualized, the majority of cases are detected at an advanced stage. Optical imaging and spectroscopy may provide a solution to the need for non-invasive and effective early detection tools. These technologies are capable of examining tissue over a wide range of spatial scales, with widefield macroscopic imaging typically spanning several square-centimeters, and high resolution in vivo microscopy techniques enabling cellular and subcellular features to be visualized. This work presents novel technologies in two important areas of optical imaging: high resolution imaging and widefield imaging. For subcellular imaging applications, new high resolution endomicroscope techniques are presented with improved lateral resolution, larger field-of-view, increased contrast, decreased background signal, and reduced cost compared to existing devices. A new widefield optical technology called multi-modal spectral imaging is also developed. This technique provides real-time in vivo spectral data over a large field-of-view, which is useful for detecting biochemical alterations associated with neoplasia. The described devices are compared to existing technologies, tested using ex vivo tissue specimens, and evaluated for diagnostic potential in a multi-patient oral cancer clinical trial
Real-time video mosaicing with a high-resolution microendoscope
Microendoscopes allow clinicians to view subcellular features in
vivo and in real-time, but their field-of-view is inherently limited by the
small size of the probe's distal end. Video mosaicing has emerged as an
effective technique to increase the acquired image size. Current
implementations are performed post-procedure, which removes the benefits
of live imaging. In this manuscript we present an algorithm for real-time
video mosaicing using a low-cost high-resolution microendoscope. We
present algorithm execution times and show image results obtained from in
vivo tissue
Automated deep learning segmentation of high-resolution 7 T postmortem MRI for quantitative analysis of structure-pathology correlations in neurodegenerative diseases
Postmortem MRI allows brain anatomy to be examined at high resolution and to
link pathology measures with morphometric measurements. However, automated
segmentation methods for brain mapping in postmortem MRI are not well
developed, primarily due to limited availability of labeled datasets, and
heterogeneity in scanner hardware and acquisition protocols. In this work, we
present a high resolution of 135 postmortem human brain tissue specimens imaged
at 0.3 mm isotropic using a T2w sequence on a 7T whole-body MRI scanner.
We developed a deep learning pipeline to segment the cortical mantle by
benchmarking the performance of nine deep neural architectures, followed by
post-hoc topological correction. We then segment four subcortical structures
(caudate, putamen, globus pallidus, and thalamus), white matter
hyperintensities, and the normal appearing white matter. We show generalizing
capabilities across whole brain hemispheres in different specimens, and also on
unseen images acquired at 0.28 mm^3 and 0.16 mm^3 isotropic T2*w FLASH sequence
at 7T. We then compute localized cortical thickness and volumetric measurements
across key regions, and link them with semi-quantitative neuropathological
ratings. Our code, Jupyter notebooks, and the containerized executables are
publicly available at: https://pulkit-khandelwal.github.io/exvivo-brain-upennComment: Preprint submitted to NeuroImage Project website:
https://pulkit-khandelwal.github.io/exvivo-brain-upen
Analyzing the Bison Gallery Art Community
The Bison village is an experimental community that offers a space for artists and craftsmen to find creative freedom. Throughout our time at Bison we took pictures, recorded our experience and collected the stories of the residents to compile them into a scrapbook to present to them. Through the use of interviews, engaged conversations and working alongside people we were able to learn about their backgrounds and motivation. Throughout our time in the community we picked up on four key discoveries, those being freedom, creativity, sustainability and community. We found that these four act as pillars within not just the current members of the community but also for those who wish to get involved
Media 3: Real-time video mosaicing with a high-resolution microendoscope
Originally published in Biomedical Optics Express on 01 October 2012 (boe-3-10-2428
Media 2: Real-time video mosaicing with a high-resolution microendoscope
Originally published in Biomedical Optics Express on 01 October 2012 (boe-3-10-2428