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Bioimaging and Biomedical Optics

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Articles 1 - 30 of 481

Full-Text Articles in Biomedical Engineering and Bioengineering

Investigation Of The Effect Of Age On Regenerative Outcomes Following Treatment Of Volumetric Muscle Loss Injuries, John Taehwan Kim Aug 2019

Investigation Of The Effect Of Age On Regenerative Outcomes Following Treatment Of Volumetric Muscle Loss Injuries, John Taehwan Kim

Theses and Dissertations

Volumetric muscle loss (VML) is a traumatic injury in skeletal muscle resulting in the bulk loss of more than 20% of the muscle’s volume. Included in the bulk loss of muscle is the skeletal muscle niche comprised of nerve bundles, vasculature, local progenitor cells, basal lamina, and muscle fibers, overwhelming innate repair mechanisms. The hallmark of VML injury is the excessive accumulation of non-contractile, fibrotic tissue and permanent functional deficits. Though predominant in the younger demographic, the elderly population is also captured within VML injuries. There are many factors that change with aging in skeletal muscle that may further ...


Multimodal Quantitative Imaging Of Brain Cancer In Cultured Cells, Xin Feng, Alona Muzikansky, Alonzo H. Ross, Michael R. Hamblin, Peter R. Jermain, Anna N. Yaroslavsky Jul 2019

Multimodal Quantitative Imaging Of Brain Cancer In Cultured Cells, Xin Feng, Alona Muzikansky, Alonzo H. Ross, Michael R. Hamblin, Peter R. Jermain, Anna N. Yaroslavsky

Open Access Articles

Fluorescence emission, polarization and subcellular localization of methylene blue (MB) were studied in four cancerous and two normal human brain cell lines. Fluorescence emission and polarization images were acquired and analyzed. The co-localization of MB with mitochondria, lysosomes and nuclei of the cells was evaluated. Glioblastoma cells exhibited significantly higher MB fluorescence polarization compared to normal astrocytes. Preferential accumulation of MB in mitochondria of glioblastoma cells may explain higher fluorescence polarization values in cancer cells as compared to normal. These findings may lead to the development of a quantitative method for the detection of brain cancer in single cells.


Resolving Intravoxel White Matter Structures In The Human Brain Using Regularized Regression And Clustering, Andrea Hart, Brianna Smith, Sean Smith, Elijah Sales, Jacqueline Hernandez-Camargo, Yarlin Mayor Garcia, Felix Zhan, Lori Griswold, Brian Dunkelberger, Michael R. Schwob, Sharang Chaudhry, Justin Zhan, Laxmi Gewali, Paul Oh Jul 2019

Resolving Intravoxel White Matter Structures In The Human Brain Using Regularized Regression And Clustering, Andrea Hart, Brianna Smith, Sean Smith, Elijah Sales, Jacqueline Hernandez-Camargo, Yarlin Mayor Garcia, Felix Zhan, Lori Griswold, Brian Dunkelberger, Michael R. Schwob, Sharang Chaudhry, Justin Zhan, Laxmi Gewali, Paul Oh

Computer Science Faculty Publications

The human brain is a complex system of neural tissue that varies significantly between individuals. Although the technology that delineates these neural pathways does not currently exist, medical imaging modalities, such as diffusion magnetic resonance imaging (dMRI), can be leveraged for mathematical identification. The purpose of this work is to develop a novel method employing machine learning techniques to determine intravoxel nerve number and direction from dMRI data. The method was tested on multiple synthetic datasets and showed promising estimation accuracy and robustness for multi-nerve systems under a variety of conditions, including highly noisy data and imprecision in parameter assumptions.


Spatial Frequency Domain Imaging Of Short-Wave Infrared Fluorescence For Biomedical Applications, Joseph P. Leonor Jun 2019

Spatial Frequency Domain Imaging Of Short-Wave Infrared Fluorescence For Biomedical Applications, Joseph P. Leonor

ENGS 88 Honors Thesis (AB Students)

Fluorescence imaging has become a standard in many clinical applications, such as tumor and vasculature imaging. One application that is becoming more prominent in cancer treatment is fluorescence-guided surgery (FGS). Currently, FGS allows surgeons the ability to visually navigate tumors and tissue structures intraoperatively. As a result, they can remove tumor more efficiently while maintaining critical structures within the patient, creating better outcomes and lower recovery times. However, background fluorescence and inability to localize depth create challenges when determining resection boundaries.

Different techniques, such as spatially modulating the illumination and imaging at longer light wavelengths, have been developed to accurately ...


Designing A Low-Cost Ultrasound Pulser, Andrea Huey Jun 2019

Designing A Low-Cost Ultrasound Pulser, Andrea Huey

Honors Theses

Ultrasound imaging allows for those studying living beings to see inside a subject without causing it harm. This allows for real-time images to be taken, leading to ease of observational research. However, while this technology is beneficial to those who utilize it, the devices used to create and receive ultrasound pulses can be incredibly complex, allowing for precise adjustment of the output signal and various other functions, and therefore expensive. The focus of this senior project is the design of a low-cost pulser for use with an ultrasound transducer. While it does not have all the high-level functions of the ...


A Multimodal Approach To Investigate Brain Reorganization After Spinal Cord Injury Using Functional Magnetic Resonance Imaging And Functional Near-Infrared Spectroscopy, Keerthana Deepti Karunakaran May 2019

A Multimodal Approach To Investigate Brain Reorganization After Spinal Cord Injury Using Functional Magnetic Resonance Imaging And Functional Near-Infrared Spectroscopy, Keerthana Deepti Karunakaran

Dissertations

Traumatic Spinal Cord Injury (SCI) results in structural and functional neurological changes at both the brain and the level of the spinal cord. Anatomical studies indicate decreased grey matter volume in sensorimotor and non-sensorimotor regions of the cortex following SCI; whereas, neurophysiological findings mostly report altered functional activity in the sensorimotor nodes of the cortex, subcortex, and cerebellum. Therefore, it is currently unknown whether tissue atrophy observed in non-motor related areas has any concomitant functional consequences. Furthermore, the neural underpinnings of adaptive neuroplasticity after SCI is not well-defined in the current literature. Hence, this dissertation is a pioneer study investigating ...


Dual Modality Optical Coherence Tomography : Technology Development And Biomedical Applications, Farzana Rahmat Zaki May 2019

Dual Modality Optical Coherence Tomography : Technology Development And Biomedical Applications, Farzana Rahmat Zaki

Dissertations

Optical coherence tomography (OCT) is a cross-sectional imaging modality that is widely used in clinical ophthalmology and interventional cardiology. It is highly promising for in situ characterization of tumor tissues. OCT has high spatial resolution and high imaging speed to assist clinical decision making in real-time.

OCT can be used in both structural imaging and mechanical characterization. Malignant tumor tissue alters morphology. Additionally, structural OCT imaging has limited tissue differentiation capability because of the complex and noisy nature of the OCT signal. Moreover, the contrast of structural OCT signal derived from tissue’s light scattering properties has little chemical specificity ...


Quantifying Iron Overload Using Mri, Active Contours, And Convolutional Neural Networks, Andrea Sajewski, Stacey Levine May 2019

Quantifying Iron Overload Using Mri, Active Contours, And Convolutional Neural Networks, Andrea Sajewski, Stacey Levine

Undergraduate Research and Scholarship Symposium

Iron overload, a complication of repeated blood transfusions, can cause tissue damage and organ failure. The body has no regulatory mechanism to excrete excess iron, so iron overload must be closely monitored to guide therapy and measure treatment response. The concentration of iron in the liver is a reliable marker for total body iron content and is now measured noninvasively with magnetic resonance imaging (MRI). MRI produces a diagnostic image by measuring the signals emitted from the body in the presence of a constant magnetic field and radiofrequency pulses. At each pixel, the signal decay constant, T2*, can be calculated ...


A Simplified Crossing Fiber Model In Diffusion Weighted Imaging, Sheng Yang, Kaushik Ghosh, Ken Sakaie, Satya S. Sahoo, Sarah J. Ann Carr, Curtis Tatsuoka May 2019

A Simplified Crossing Fiber Model In Diffusion Weighted Imaging, Sheng Yang, Kaushik Ghosh, Ken Sakaie, Satya S. Sahoo, Sarah J. Ann Carr, Curtis Tatsuoka

Math Faculty Publications

Diffusion MRI (dMRI) is a vital source of imaging data for identifying anatomical connections in the living human brain that form the substrate for information transfer between brain regions. dMRI can thus play a central role toward our understanding of brain function. The quantitative modeling and analysis of dMRI data deduces the features of neural fibers at the voxel level, such as direction and density. The modeling methods that have been developed range from deterministic to probabilistic approaches. Currently, the Ball-and-Stick model serves as a widely implemented probabilistic approach in the tractography toolbox of the popular FSL software package and ...


Seeing Eye To Eye: A Machine Learning Approach To Automated Saccade Analysis, Maigh Attre May 2019

Seeing Eye To Eye: A Machine Learning Approach To Automated Saccade Analysis, Maigh Attre

Honors Scholar Theses

Abnormal ocular motility is a common manifestation of many underlying pathologies particularly those that are neurological. Dynamics of saccades, when the eye rapidly changes its point of fixation, have been characterized for many neurological disorders including concussions, traumatic brain injuries (TBI), and Parkinson’s disease. However, widespread saccade analysis for diagnostic and research purposes requires the recognition of certain eye movement parameters. Key information such as velocity and duration must be determined from data based on a wide set of patients’ characteristics that may range in eye shapes and iris, hair and skin pigmentation [36]. Previous work on saccade analysis ...


Investigation Of Acute Radiation-Induced Changes In Oxygenation In A Murine Breast Tumor Model, Alaa Abdelgawad May 2019

Investigation Of Acute Radiation-Induced Changes In Oxygenation In A Murine Breast Tumor Model, Alaa Abdelgawad

Biomedical Engineering Undergraduate Honors Theses

Around 50-60% of all cancer patients undergo radiation therapy. Although some patients show complete response with no recurrence, a significant proportion of the population still develop radiation resistance. It is important to identify tumor resistance at early stages of therapy in order to adjust treatment protocol and avoid extra exposure to radiation. Current methods to assess treatment response are only limited to anatomical measurements of tumor volume after therapy. Novel approaches that shed the light on any functional information during the course of radiotherapy could significantly improve our ability to identify patients who do not respond to radiation therapy. Diffuse ...


Diffuse Reflectance Spectroscopy To Quantify In Vivo Tissue Optical Properties: Applications In Human Epithelium And Subcutaneous Murine Colon Cancer, Gage Joseph Greening May 2019

Diffuse Reflectance Spectroscopy To Quantify In Vivo Tissue Optical Properties: Applications In Human Epithelium And Subcutaneous Murine Colon Cancer, Gage Joseph Greening

Theses and Dissertations

Colorectal cancer is the 4th most common and 2nd deadliest cancer. Problems exist with predicting which patients will respond best to certain therapy regimens. Diffuse reflectance spectroscopy has been suggested as a candidate to optically monitor a patient’s early response to therapy and has been received favorably in experimentally managing other cancers such as breast and skin. In this dissertation, two diffuse reflectance spectroscopy probes were designed: one with a combined high-resolution microendoscopy modality, and one that was optimized for acquiring data from subcutaneous murine tumors. For both probes, percent errors for estimating tissue optical properties (reduced scattering coefficient ...


Biomedical Engineering Or Biomedical Optics: Will The Real Discipline Please Stand Up?, Brian W. Pogue Apr 2019

Biomedical Engineering Or Biomedical Optics: Will The Real Discipline Please Stand Up?, Brian W. Pogue

Open Dartmouth: Faculty Open Access Scholarship

This editorial reflects on the shape of biomedical engineering as a discipline, and its relation to biomedical optics.


Tissue Equivalent Gellan Gum Gel Materials For Clinical Mri And Radiation Dosimetry, Pawel Brzozowski Apr 2019

Tissue Equivalent Gellan Gum Gel Materials For Clinical Mri And Radiation Dosimetry, Pawel Brzozowski

Electronic Thesis and Dissertation Repository

Hydrogels contain high amount of water allowing their use as surrogates to human tissues with specific properties that can be tuned by additives. Gellan gum is a gel-forming material of interest and is a replacement for other common gelling agent with limited use as a tissue phantom. Therefore, this thesis examines the application of gellan gum gels as a novel magnetic resonance imaging (MRI) phantom with a design of experiments model to obtain tunable properties. The analysis was extended to include mechanical and electrical properties with a separate design of experiment. Gels doped with synthesized superparamagnetic iron oxide nanoparticles (SPIONs ...


Characterizing Short-Wave Infrared Fluorescence Of Conventional Near-Infrared Fluorophores, Brook K. Byrd, Margaret R. Folaron, Joseph P. Leonor, Rendall R. Strawbridge, Xu Cao, Petr Bruza, Scott C. Davis Mar 2019

Characterizing Short-Wave Infrared Fluorescence Of Conventional Near-Infrared Fluorophores, Brook K. Byrd, Margaret R. Folaron, Joseph P. Leonor, Rendall R. Strawbridge, Xu Cao, Petr Bruza, Scott C. Davis

Open Dartmouth: Faculty Open Access Scholarship

The observed behavior of short-wave infrared (SWIR) light in tissue, characterized by relatively low scatter and subdiffuse photon transport, has generated considerable interest for the potential of SWIR imaging to produce high-resolution, subsurface images of fluorescence activity in vivo. These properties have important implications for fluorescence-guided surgery and preclinical biomedical research. Until recently, translational efforts have been impeded by the conventional understanding that fluorescence molecular imaging in the SWIR regime requires custom molecular probes that do not yet have proven safety profiles in humans. However, recent studies have shown that two readily available near-infrared (NIR-I) fluorophores produce measurable SWIR fluorescence ...


Automated Microscope Stage, Corin Nishimoto, Alison Flesch, Theo Anastos Mar 2019

Automated Microscope Stage, Corin Nishimoto, Alison Flesch, Theo Anastos

Biomedical Engineering

This document seeks to describe the background information, customer requirements, design specifications, indications for use, selected materials, proposed budget, prototypes, final design, manufacturing processes, and testing methods regarding the CellOptimizer automated microscope stage product.


Long-Term, Super-Resolution Imaging Of Amyloid Structures Using Transient Amyloid Binding Microscopy, Tianben Ding, Kevin Spehar, Jan Bieschke, Matthew D. Lew Feb 2019

Long-Term, Super-Resolution Imaging Of Amyloid Structures Using Transient Amyloid Binding Microscopy, Tianben Ding, Kevin Spehar, Jan Bieschke, Matthew D. Lew

Electrical & Systems Engineering Publications and Presentations

Amyloid fibrils and tangles are signatures of Alzheimer disease, but nanometer-sized aggregation intermediates are hypothesized to be the structures most toxic to neurons. The structures of these oligomers are too small to be resolved by conventional light microscopy. We have developed a simple and versatile method, called transient amyloid binding (TAB), to image amyloid structures with nanoscale resolution using amyloidophilic dyes, such as Thioflavin T, without the need for covalent labeling or immunostaining of the amyloid protein. Transient binding of ThT molecules to amyloid structures over time generates photon bursts that are used to localize single fluorophores with nanometer precision ...


Diagnostic Performance Of Receptor-Specific Surgical Specimen Staining Correlates With Receptor Expression Level, Jasmin M. Schaefer, Connor W. Barth, Scott C. Davis, Summer L. Gibbs Feb 2019

Diagnostic Performance Of Receptor-Specific Surgical Specimen Staining Correlates With Receptor Expression Level, Jasmin M. Schaefer, Connor W. Barth, Scott C. Davis, Summer L. Gibbs

Open Dartmouth: Faculty Open Access Scholarship

Intraoperative margin assessment is imperative to cancer cure but is a continued challenge to successful surgery. Breast conserving surgery is a relevant example, where a cosmetically improved outcome is gained over mastectomy, but re-excision is required in >25  %   of cases due to positive or closely involved margins. Clinical translation of margin assessment modalities that must directly contact the patient or required administered contrast agents are time consuming and costly to move from bench to bedside. Tumor resections provide a unique surgical opportunity to deploy margin assessment technologies including contrast agents on the resected tissues, substantially shortening the path to the ...


Ensuring Scientific Publishing Credibility In Translational Biomedical Optics., Brian W. Pogue Jan 2019

Ensuring Scientific Publishing Credibility In Translational Biomedical Optics., Brian W. Pogue

Open Dartmouth: Faculty Open Access Scholarship

Optics has consistently been the largest singular technology sector used in medicine, and major advances in biomedical optics are documented daily in peer-reviewed publications. However, the academic stature of this field can be damaged by weaknesses in scientific publishing, where a “credibility crisis” has emerged as a popularized and increasingly studied dialogue. While there are still relatively few overt cases of fraud or erroneous research, more insidious aspects are seen in papers with results that have either low statistical power, selective reporting of observations, or data or computer codes that cannot be independently verified. Interestingly, the same solutions that improve ...


Abso2luteu-Net: Tissue Oxygenation Calculation Using Photoacoustic Imaging And Convolutional Neural Networks, Kevin Hoffer-Hawlik, Geoffrey P. Luke Jan 2019

Abso2luteu-Net: Tissue Oxygenation Calculation Using Photoacoustic Imaging And Convolutional Neural Networks, Kevin Hoffer-Hawlik, Geoffrey P. Luke

ENGS 88 Honors Thesis (AB Students)

Photoacoustic (PA) imaging uses incident light to generate ultrasound signals within tissues. Using PA imaging to accurately measure hemoglobin concentration and calculate oxygenation (sO2) requires prior tissue knowledge and costly computational methods. However, this thesis shows that machine learning algorithms can accurately and quickly estimate sO2. absO2luteU-Net, a convolutional neural network, was trained on Monte Carlo simulated multispectral PA data and predicted sO2 with higher accuracy compared to simple linear unmixing, suggesting machine learning can solve the fluence estimation problem. This project was funded by the Kaminsky Family Fund and the Neukom Institute.


Noninvasive Multimodal Diffuse Optical Imaging Of Vulnerable Tissue Hemodynamics, Mingjun Zhao Jan 2019

Noninvasive Multimodal Diffuse Optical Imaging Of Vulnerable Tissue Hemodynamics, Mingjun Zhao

Theses and Dissertations--Biomedical Engineering

Measurement of tissue hemodynamics provides vital information for the assessment of tissue viability. This thesis reports three noninvasive near-infrared diffuse optical systems for spectroscopic measurements and tomographic imaging of tissue hemodynamics in vulnerable tissues with the goal of disease diagnosis and treatment monitoring. A hybrid near-infrared spectroscopy/diffuse correlation spectroscopy (NIRS/DCS) instrument with a contact fiber-optic probe was developed and utilized for simultaneous and continuous monitoring of blood flow (BF), blood oxygenation, and oxidative metabolism in exercising gastrocnemius. Results measured by the hybrid NIRS/DCS instrument in 37 subjects (mean age: 67 ± 6) indicated that vitamin D supplement plus ...


Calibrated Short Tr Recovery Mri For Rapid Measurement Of Brain-Blood Partition Coefficient And Correction Of Quantitative Cerebral Blood Flow, Scott William Thalman Jan 2019

Calibrated Short Tr Recovery Mri For Rapid Measurement Of Brain-Blood Partition Coefficient And Correction Of Quantitative Cerebral Blood Flow, Scott William Thalman

Theses and Dissertations--Biomedical Engineering

The high prevalence and mortality of cerebrovascular disease has led to the development of several methods to measure cerebral blood flow (CBF) in vivo. One of these, arterial spin labeling (ASL), is a quantitative magnetic resonance imaging (MRI) technique with the advantage that it is completely non-invasive. The quantification of CBF using ASL requires correction for a tissue specific parameter called the brain-blood partition coefficient (BBPC). Despite regional and inter-subject variability in BBPC, the current recommended implementation of ASL uses a constant assumed value of 0.9 mL/g for all regions of the brain, all subjects, and even all ...


Quantification Of Myocardial Mechanics In Left Ventricles Under Inotropic Stimulation And In Healthy Right Ventricles Using 3d Dense Cmr, Zhan-Qiu Liu Jan 2019

Quantification Of Myocardial Mechanics In Left Ventricles Under Inotropic Stimulation And In Healthy Right Ventricles Using 3d Dense Cmr, Zhan-Qiu Liu

Theses and Dissertations--Mechanical Engineering

Statistical data from clinical studies indicate that the death rate caused by heart disease has decreased due to an increased use of evidence-based medical therapies. This includes the use of magnetic resonance imaging (MRI), which is one of the most common non-invasive approaches in evidence-based health care research. In the current work, I present 3D Lagrangian strains and torsion in the left ventricle of healthy and isoproterenol-stimulated rats, which were investigated using Displacement ENcoding with Stimulated Echoes (DENSE) cardiac magnetic resonance (CMR) imaging. With the implementation of the 12-segment model, a detailed profile of regional cardiac mechanics was reconstructed for ...


Textured Contact Lens Based Iris Presentation Attack In Uncontrolled Environment, Daksha Yadav Jan 2019

Textured Contact Lens Based Iris Presentation Attack In Uncontrolled Environment, Daksha Yadav

Graduate Theses, Dissertations, and Problem Reports

The widespread use of smartphones has spurred the research in mobile iris devices. Due to their convenience, these mobile devices are also utilized in unconstrained outdoor conditions. At the same time, iris recognition in the visible spectrum has developed into an active area of research. These scenarios have necessitated the development of reliable iris recognition algorithms for such an uncontrolled environment. Additionally, iris presentation attacks such as textured contact lens pose a major challenge to current iris recognition systems.

Motivated by these factors, in this thesis, a detailed analysis of the effect of textured contact lenses on iris recognition in ...


Glioma Grading Using Structural Magnetic Resonance Imaging And Molecular Data, Syed M.S. Reza, Manar D. Samad, Zeina A. Shboul, Karra A. Jones, Khan M. Iftekharuddin Jan 2019

Glioma Grading Using Structural Magnetic Resonance Imaging And Molecular Data, Syed M.S. Reza, Manar D. Samad, Zeina A. Shboul, Karra A. Jones, Khan M. Iftekharuddin

Electrical & Computer Engineering Faculty Publications

A glioma grading method using conventional structural magnetic resonance image (MRI) and molecular data from patients is proposed. The noninvasive grading of glioma tumors is obtained using multiple radiomic texture features including dynamic texture analysis, multifractal detrended fluctuation analysis, and multiresolution fractal Brownian motion in structural MRI. The proposed method is evaluated using two multicenter MRI datasets: (1) the brain tumor segmentation (BRATS-2017) challenge for high-grade versus low-grade (LG) and (2) the cancer imaging archive (TCIA) repository for glioblastoma (GBM) versus LG glioma grading. The grading performance using MRI is compared with that of digital pathology (DP) images in the ...


Optical Vortex And Poincaré Analysis For Biophysical Dynamics, Anindya Majumdar Jan 2019

Optical Vortex And Poincaré Analysis For Biophysical Dynamics, Anindya Majumdar

Dissertations, Master's Theses and Master's Reports

Coherent light - such as that from a laser - on interaction with biological tissues, undergoes scattering. This scattered light undergoes interference and the resultant field has randomly added phases and amplitudes. This random interference pattern is known as speckles, and has been the subject of multiple applications, including imaging techniques. These speckle fields inherently contain optical vortices, or phase singularities. These are locations where the intensity (or amplitude) of the interference pattern is zero, and the phase is undefined.

In the research presented in this dissertation, dynamic speckle patterns were obtained through computer simulations as well as laboratory setups involving scattering ...


Radiolabeled Nanohydroxyapatite As A Platform For The Development Of New Pet Imaging Agents, Stacy Lee Queern Dec 2018

Radiolabeled Nanohydroxyapatite As A Platform For The Development Of New Pet Imaging Agents, Stacy Lee Queern

Arts & Sciences Electronic Theses and Dissertations

Positron emission tomography (PET) imaging utilizes drugs labeled with positron emitters to target and evaluate different biological processes occurring in the body. Tailoring medicine to the individual allows for higher quality of care with better diagnosis and treatment and is a key purpose for advancing research into developing new platforms for PET imaging agents. A PET nuclide of high interest for the development of these agents is 89Zr. This can be attributed to the long half-life of 3.27 days and low positron energy of 89Zr.

In this work, we developed a production method for 89Zr using Y sputtered coins ...


Manganese-Enhanced Magnetic Resonance Imaging: Overview And Central Nervous System Applications With A Focus On Neurodegeneration, Ryan A. Cloyd, Shon A. Koren, Jose F. Abisambra Dec 2018

Manganese-Enhanced Magnetic Resonance Imaging: Overview And Central Nervous System Applications With A Focus On Neurodegeneration, Ryan A. Cloyd, Shon A. Koren, Jose F. Abisambra

Physiology Faculty Publications

Manganese-enhanced magnetic resonance imaging (MEMRI) rose to prominence in the 1990s as a sensitive approach to high contrast imaging. Following the discovery of manganese conductance through calcium-permeable channels, MEMRI applications expanded to include functional imaging in the central nervous system (CNS) and other body systems. MEMRI has since been employed in the investigation of physiology in many animal models and in humans. Here, we review historical perspectives that follow the evolution of applied MRI research into MEMRI with particular focus on its potential toxicity. Furthermore, we discuss the more current in vivo investigative uses of MEMRI in CNS investigations and ...


Morphological Features Of Dysplastic Progression In Epithelium: Quantification Of Cytological, Microendoscopic, And Second Harmonic Generation Images, Sandra Patricia Gordon Dec 2018

Morphological Features Of Dysplastic Progression In Epithelium: Quantification Of Cytological, Microendoscopic, And Second Harmonic Generation Images, Sandra Patricia Gordon

Theses and Dissertations

Advances in imaging technology have led to a variety of available clinical and investigational systems. In this collection of studies, we tested the relevance of morphological image feature quantification on several imaging systems and epithelial tissues. Quantification carries the benefit of creating numerical baselines and thresholds of healthy and abnormal tissues, to potentially aid clinicians in determining a diagnosis, as well as providing researchers with standardized, unbiased results for future dissemination and comparison.

Morphological image features in proflavine stained oral cells were compared qualitatively to traditional Giemsa stained cells, and then we quantified the nuclear to cytoplasm ratio. We determined ...


Cherenkov Excited Short-Wavelength Infrared Fluorescence Imaging In Vivo With External Beam Radiation, Xu Cao, Shudong Jiang, Mengyu Jeremy Jia, Jason R. Gunn, Tianshun Miao, Scott C. Davis, Petr Bruza, Brian W. Pogue Nov 2018

Cherenkov Excited Short-Wavelength Infrared Fluorescence Imaging In Vivo With External Beam Radiation, Xu Cao, Shudong Jiang, Mengyu Jeremy Jia, Jason R. Gunn, Tianshun Miao, Scott C. Davis, Petr Bruza, Brian W. Pogue

Open Dartmouth: Faculty Open Access Scholarship

Cherenkov emission induced by external beam radiation therapy from a clinical linear accelerator (LINAC) can be used to excite phosphors deep in biological tissues. As with all luminescence imaging, there is a desire to minimize the spectral overlap between the excitation light and emission wavelengths, here between the Cherenkov and the phosphor. Cherenkov excited short-wavelength infrared (SWIR, 1000 to 1700 nm) fluorescence imaging has been demonstrated for the first time, using long Stokes-shift fluorophore PdSe quantum dots (QD) with nanosecond lifetime and an optimized SWIR detection. The 1  /  λ2 intensity spectrum characteristic of Cherenkov emission leads to low overlap of ...