Scholars@Duke
Nimmi Ramanujam

Nimmi Ramanujam

Robert W. Carr, Jr., Distinguished Professor of Biomedical Engineering
Biomedical Engineering
Box 90281, 1427 FCIEMAS, Durham, NC 27708-0281
367 Gross Hall, 140 Science Drive, Durham, NC 27708

Scholarly Works - Conferences

Development of Image Pre-processing Toolbox to Boost Cervical Cancer Detection

Conference Progress in Biomedical Optics and Imaging Proceedings of SPIE · January 1, 2025 Globally, inequitable resources and access cause cervical cancer remain the fourth leading cause of death in women. Risk stratification with human papilloma virus (HPV) screening is fundamental in identifying vulnerable populations. Visual inspection with ... Full text Cite

Multi-probe Metabolic Fluorescence Microscopy Captures Poor Tumor Immunogenicity

Conference Optical Molecular Probes Imaging and Drug Delivery Omp 2025 in Proceedings Optica Biophotonics Congress 2025 Part of Optica Biophotonics Congress Optics in the Life Sciences · January 1, 2025 Visualizing complex tumor-immune metabolic interactions is imperative to understanding cancer progression. Cocultures of 4T1 tumor cells and CD8+ T cells were imaged for glucose uptake and mitochondrial metabolism. Results point to poor immunogenic tumor p ... Full text Cite

A Multiplexed Quantitative Spectroscopy Method to Measure Spectrally Overlapping Metabolic Fluorophores

Conference Novel Optical Materials and Applications Noma 2024 in Proceedings Advanced Photonics Congress 2024 Part of Optica Advanced Photonics Congress · January 1, 2024 We have developed and validated an in vivo quantitative spectroscopy method to measure spectrally overlapping fluorophores relevant to cancer metabolism using an inverse Monte Carlo algorithm and linear spectral unmixing. ... Cite

Abstract P6-01-01: Validation of an Optical Imaging Platform to Identify Metabolic Vulnerabilities in Chemo-Resistant and Sensitive Tumors

Conference Cancer Research · March 1, 2023 AbstractLess than 20% of Triple Negative Breast Cancer (TNBC) patients experience long-term responses to mainstay chemotherapy, as tumors develop chemo-resistance. While combinations of chemotherapies and ta ... Full text Cite

In Vivo Metabolic Imaging Reveals Mitochondrial Membrane Potential Reprogramming During Residual Disease Following Chemotherapy

Conference Optical Molecular Probes Imaging and Drug Delivery Omp 2023 · January 1, 2023 We performed intravital fluorescent microscopy in preclinical models of disease regression in Triple Negative Breast Cancer to compare dynamic, long-term in vivo changes across three major metabolic axes in chemotherapy-resistant and chemotherapy-sensitive ... Cite

Development of a multi-scale platform to quantify metabolic heterogeneity in vivo

Conference Optical Molecular Probes Imaging and Drug Delivery Omp 2023 · January 1, 2023 We developed an approach to quantify intratumoral metabolic heterogeneity of in vivo tumor models by leveraging a computationally designed multi-scale microscope and a suite of exogenous fluorescent contrast agents to provide functional and structural info ... Cite

Resetting the tumor microenvironment to favor anti-tumor immunity after local ablation.

Conference Journal of Clinical Oncology · May 20, 2021 2561 Background: Percutaneous tumor ablation is a non-surgical method of tumor destruction that leaves necrotic tumor debris in situ. Tumor associated antigens released after ablation have the potential to initiate a systemic ant ... Full text Cite

A novel treatment for recurrent localized cervical cancer using point-of-care ethyl cellulose ethanol ablation with concurrent cytotoxic therapy.

Conference Journal of Clinical Oncology · May 20, 2021 e17507 Background: Historically, the only curative option for patients with recurrent localized cervical cancer after platinum-based chemotherapy and radiation is pelvic exenteration. For non-surgical candidates, treatment option ... Full text Cite

Combining multiple contrasts for improving machine learning-based classification of cervical cancers with a low-cost point-of-care Pocket colposcope.

Conference Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual International Conference · July 2020 We apply feature-extraction and machine learning methods to multiple sources of contrast (acetic acid, Lugol's iodine and green light) from the white Pocket Colposcope, a low-cost point of care colposcope for cervical cancer screening. We combine features ... Full text Cite

Leveraging surface Hsp90 expression for rapid-on-site breast cancer diagnostics

Conference Optics Infobase Conference Papers · January 1, 2020 We developed a portable, low-cost, handheld fluorescent microscope to perform rapid heat shock protein 90 (Hsp90) molecular imaging. The source of non-specific signal and diffusion kinetics of the probe is studied. ... Cite

In vivo metabolic imaging reveals mitochondrial membrane potential reprogramming following Her2-targeted therapy and dormant disease

Conference Optics Infobase Conference Papers · January 1, 2020 We performed in intravital fluorescent microscopy in a preclinical cancer dormancy model to capture key changes in mitochondrial activity associated with Her2 treated breast cancer both acutely and in a residual disease state. ... Cite

Image processing and machine learning techniques to automate diagnosis of Lugol's iodine cervigrams for a low-cost point-of-care digital colposcope

Conference Progress in Biomedical Optics and Imaging Proceedings of SPIE · January 1, 2018 The world health organization recommends visual inspection with acetic acid (VIA) and/or Lugol's Iodine (VILI) for cervical cancer screening in low-resource settings. Human interpretation of diagnostic indicators for visual inspection is qualitative, subje ... Full text Cite

Optimizing fluorescently-tethered Hsp90 inhibitor dose for maximal specific uptake by breast tumors

Conference Progress in Biomedical Optics and Imaging Proceedings of SPIE · January 1, 2018 Despite improvements in surgical resection, 20-40% of patients undergoing breast conserving surgery require at least one additional re-excision. Leveraging the unique surface expression of heat shock protein 90 (Hsp90), a chaperone protein involved in seve ... Full text Cite

Non-invasive, simultaneous quantification of vascular oxygenation, glucose uptake and mitochondria membrane potential in a flank tumor model

Conference Optics Infobase Conference Papers · January 1, 2018 For the first time, we performed simultaneous in vivo spectroscopy of tissue hemoglobin, 2-NBDG, and TMRE in a preclinical model, to successfully capture vascular and metabolic parameters in vivo in solid tumors. ... Full text Cite

Preventing over treatment through smart health technologies

Conference Optics Infobase Conference Papers · January 1, 2018 The cost of cancer care in the U.S. was $125 billion in 2010 and is projected to increase to $175 billion by 2020. Total spending on cancer care is driven by the cost to treat an individual patient and the number of patients treated. For example, sipuleuce ... Full text Cite

Clinical evaluation of a portable pocket colposcope for cervical cancer screening in the United States, Perú, and Tanzania

Conference 2017 IEEE Healthcare Innovations and Point of Care Technologies Hi Poct 2017 · December 19, 2017 Cervical cancer is the second leading cause of cancer related deaths for women worldwide, despite being both preventable and treatable if detected early enough. The burden of disease persists in part due to a lack of access to early diagnostics and the fac ... Full text Cite

Imaging of 2-NBDG and TMRE reveals glucose uptake and mitochondrial membrane potential in dorsal window chamber models

Conference Optics Infobase Conference Papers · January 1, 2017 For the first time, we performed simultaneous in vivo microscopic imaging of 2-NBDG and TMRE in a preclinical model, to successfully capture glucose and mitochondrial membrane potential on the same tissue site at one time. ... Full text Cite

Label-free vascular imaging in a spontaneous hamster cheek pouch carcinogen model for pre-cancer detection (Conference Presentation)

Conference Optical Biopsy XIV: Toward Real-Time Spectroscopic Imaging and Diagnosis · April 26, 2016 Full text Cite

Portable system for wide-field, sub-millimeter functional imaging of the morphological landscape of breast tumor margins

Conference Optics Infobase Conference Papers · April 18, 2016 We have developed a portable, breast margin assessment probe (BMAP) that surgeons can use to evaluate the breast tumor margin status during surgery. The approach presented here leverages a custom16-channel photodiode array raster-scanning-based system with ... Full text Cite

Hyperspectral imaging of glucose uptake, mitochondrial membrane potential, and vascular oxygenation differentiates breast cancers with distinct metastatic potential in vivo

Conference Optics Infobase Conference Papers · January 1, 2016 We performed in vivo hyperspectral imaging in a preclinical cancer model to capture key metabolic endpoints (glucose uptake, mitochondrial membrane potential, and vascular oxygenation) to successfully distinguish metastatic and non-metastatic tumors. ... Full text Cite

Integrated dual-modal microscope for imaging of key metabolic and vascular endpoints in preclinical cancer models

Conference Optics Infobase Conference Papers · January 1, 2016 We have developed and utilized a wide field, high resolution microscope to capture multiple key metabolic and vascular endpoints to different indolent from metastatic disease. ... Full text Cite

Abstract B48: Optical toolbox for in vivo analysis of glucose uptake, vascular oxygenation, and mitochondrial membrane potential in breast cancer

Conference Molecular Cancer Research · January 1, 2016 AbstractThe goal of this work is development of a fast and repeatable optical assay that uses a novel combination of fluorophores and endogenous contrast to report on the metabolic phenotype of cancers in vi ... Full text Cite

Abstract B45: Optical spectroscopy of tumor oxygenation and metabolism in preclinical head and neck tumors that fail radiation therapy

Conference Molecular Cancer Research · January 1, 2016 AbstractThe purpose of this study was to determine the role of tumor metabolism and its relationship with tumor oxygenation in driving radiation resistance in head and neck cancer. The use of anatomical endp ... Full text Cite

Optical monitoring of glucose demand and vascular delivery in a preclinical murine model

Conference Progress in Biomedical Optics and Imaging Proceedings of SPIE · January 1, 2014 Targeted therapies such as PI3K inhibition can affect tumor vasculature, and hence delivery of imaging agents like FDG, while independently modifying intrinsic glucose demand. Therefore, it is important to identify whether perceived changes in glucose upta ... Full text Cite

Abstract C86: Tethered Hsp90 inhibitors carrying optical or radioiodinated probes reveal selective internalization of ectopic Hsp90 in malignant breast tumor cells.

Conference Molecular Cancer Therapeutics · November 1, 2013 AbstractHsp90 inhibitors have demonstrated unusual selectivity for tumor cells despite its ubiquitous expression. This phenomenon has remained unexplained but could be influenced by ectopically expressed Hsp ... Full text Cite

Image-Guided Oncologic Surgery

Conference MEDICAL PHYSICS · June 2012 Full text Link to item Cite

In Vivo estimation of total hemoglobin concentration and hemoglobin saturation in the detection of cervical epithelial pre-cancers

Conference Optics Infobase Conference Papers · January 1, 2007 Total hemoglobin concentration, hemoglobin saturation and scattering coefficient were extracted from cervical diffuse reflectance spectra (400-600 nm) using a Monte Carlo-based model. Total hemoglobin was shown to distinguish pre-cancerous from normal tiss ... Full text Cite

Physiologic, metabolic, and structural alterations in breast cancer: Assessment via optical technologies

Conference Optics Infobase Conference Papers · January 1, 2006 Optical spectroscopy was used to assess structural and functional changes which occur in breast tissue for the optical diagnosis of cancer in humans in vivo, and characterization of mammary tumor biology in animal models. © 2006 Optical Society of America. ... Full text Cite

Use of genetic algorithms to optimize fiber optic probe design for the extraction of tissue optical properties

Conference Optics Infobase Conference Papers · January 1, 2006 An approach for optimizing the probe geometry for extracting optical properties is developed. It was found that optical properties could be extracted with accuracies of better than 0.5 cm-1, while requiring no a priori assumptions. © 2005 Optica ... Full text Cite

Physiologic, Metabolic, and Structural Alterations in Breast Cancer: Assessment via Optical Technologies

Conference Optics Infobase Conference Papers · January 1, 2006 Optical spectroscopy was used to assess structural and functional changes which occur in breast tissue for the optical diagnosis of cancer in humans in vivo, and characterization of mammary tumor biology in animal models. ... Cite

Monte Carlo based inverse model of diffuse reflectance for determination of UV-VIS optical properties and its application to breast cancer diagnosis

Conference Optics Infobase Conference Papers · January 1, 2004 A method for extracting optical properties from diffuse reflectance spectra is applied to human breast tissue. It was found that using the physically-based model for classification of malignancy performed substantially better than an empirical model. ... Cite

Multiphoton imaging of endogenous fluorescence in neoplastic and non-neoplastic epithelial tissues

Conference Optics Infobase Conference Papers · January 1, 2004 Endogenous fluorescence offers promise for diagnosing oral cancers. This is the first study to use multiphoton imaging to characterize the spatial and depth distribution of endogenous fluorescence in neoplastic and non-neoplastic epithelial tissues. ... Cite

Transabdominal Near-infrared Fetal Brain Oximetry

Conference Optics Infobase Conference Papers · January 1, 2004 The feasibility of transabdominal near-infrared spectroscopy for detecting and quantifying fetal hypoxia in utero is demonstrated in a pregnant ewe model. ... Cite

Imaging collagen in a dermal equivalent using multi-photon microscopy

Conference Optics Infobase Conference Papers · January 1, 2004 Nondestructive imaging of tumor models offers a new tool for cancer research. We have imaged a dermal equivalent and measured a signal decrease using collagenase. This result indicates feasibility for measuring collagen degradation during tumorigenesis. ... Cite

The use of a multi-separation probe for optical diagnosis of breast cancer

Conference Optics Infobase Conference Papers · January 1, 2004 We explored the effects of probe-geometry on UV-VIS fluorescence and diffuse reflectance measurements from breast tissues. It shows that integrated fluorescence intensities measured with a multi-separation probe can be used to discriminate malignant from n ... Cite

Sources of optical contrast in biological tissues

Conference Optics Infobase Conference Papers · January 1, 2003 Cite

Relationship between the depth of a target in a turbid medium and the fluorescence measured using a variable aperture method

Conference Optics Infobase Conference Papers · January 1, 2002 This study shows the relationship between the depth of a target in a turbid medium and the fluorescence ratio profile measured using illumination and collection apertures with variable diameters and the same optical path. The forward problem was studied by ... Cite

Fast and non-invasive fluorescence imaging from biological signals, in vivo using a flying spot scanner

Conference Optics Infobase Conference Papers · January 1, 2000 A flying spot scanner has been developed to image fluorescence from intact tissues in near realtime. The instrument is based on a single-channel detection scheme. The scanner has been used to image fluorescence from living animal tissues undergoing various ... Cite

Comparison between homogeneous and Two-layer model for spectroscopic measurement of fetal cerebral blood oxygenation in-utero

Conference Optics Infobase Conference Papers · January 1, 2000 In order to measure the fetal cerebral oxygenation in utero, a numerical two-layer model data is generated using finite difference method in diffusion regime. The detectibility of photons through the fetal head is estimated and optical properties obtained ... Cite