Download or read book Compact and Robust Ultrasound guided Diffuse Optical Tomography for Breast Imaging System and Algorithm Developments written by Hamed Vavadi and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: According to the World Health Organization, breast cancer is the most common cancer among women worldwide, claiming lives of hundreds of thousands of women each year. Mammography, ultrasound (US) and magnetic resonance imaging (MRI) are widely used to detect and diagnose breast lesions and each of them have some disadvantages which motivates researchers to find a new and high sensitive imaging method. Diffuse optical tomography (DOT) is a noninvasive functional imaging modality that utilizes near-infrared (NIR) light to probe tissue optical properties. Minimal light absorption in the NIR spectrum allows for several centimeters of light penetration in soft tissue. NIR is sensitive to hemoglobin which is directly related to tumor angiogenesis. If multiple wavelengths are used, it can probe tumor oxygen saturation. However, DOT has drawbacks on location uncertainty and low light quantification accuracy due to tissue scattering of NIR light. Ultrasound (US)-guided Diffuse Optical Tomography has overcome these problems. The overall objective of my research is to move US-guided DOT one step closer from a research imaging modality to a commercial prototype for future wide use in clinics. To achieve this goal, I have overcome several challenges in both imaging hardware and software. In this Dissertation, I will discuss the progress we have made on development of two generations of US-guided DOT systems along with the software improvements. The developed systems have been improved in terms of robustness, stability, clinical safety and standards and user friendliness. In terms of software and algorithm development, automated methods for data selection, outlier removal and reference and perturbation filtering are presented. These methods have improved the robustness of the technique and increased speed of image formation by eliminating the need for an expert to perform data preprocessing and data selection. Phantom and clinical experimental results will be demonstrated to evaluate the performance of the developed systems and algorithms.
Download or read book Ultrasound guided Optical Techniques for Cancer Diagnosis written by Atahar Kamal Mostafa and published by . This book was released on 2019 with total page 91 pages. Available in PDF, EPUB and Kindle. Book excerpt: Worldwide, breast cancer is the most common cancer among women. In the United States alone, the American cancer society has estimated there will be 271,270 new breast cancer cases in 2019, and 42,260 lives will be lost to the disease. Ultrasound (US), mammography, and magnetic resonance imaging (MRI) are regularly used for breast cancer diagnosis and therapy monitoring. However, they sometimes fail to diagnose breast cancer effectively. These shortcomings have motivated researchers to explore new modalities. One of these modalities, diffuse optical tomography (DOT), utilizes near-infrared (NIR) light to reveal the optical properties of tissue. NIR-based DOT images the contrast between a suspected lesion's location and the background tissue, caused by the higher NIR absorption of the hemoglobin which characterizes tumors. The limitation of high light scattering inside tissue is minimized by using ultrasound image to find the tumor location.This thesis focuses on developing a compact, low-cost ultrasound guided diffuse optical tomography imaging system and on improving optical image reconstruction by extracting the tumor's location and size from co-registered ultrasound images. Several electronic components have been redesigned and optimized to save space and cost and to improve the user experience. In terms of software and algorithm development, manual extraction of tumor information from ultrasound images has been replaced by using a semi-automated ultrasound image segmentation algorithm that reduces the optical image reconstruction time and operator dependency. This system and algorithm have been validated with phantom and clinical data and have demonstrated their efficacy. An ongoing clinical trial will continue to gather more patient data to improve the robustness of the imaging algorithm.Another part of this research focuses on ovarian cancer diagnosis. Ovarian cancer is the most deadly of all gynecological cancers, with a less than 50% five-year survival rate. This cancer can evolve without any noticeable symptom, which makes it difficult to diagnose in an early stage. Although ultrasound-guided photoacoustic tomography (PAT) has demonstrated potential for early detection of ovarian cancer, clinical studies have been very limited due to the lack of robust PAT systems.In this research, we have customized a commercial ultrasound system to obtain real-time co-registered PAT and US images. This system was validated with several phantom studies before use in a clinical trial. PAT and US raw data from 30 ovarian cancer patients was used to extract spectral and statistical features for training and testing classifiers for automatic diagnosis. For some challenging cases, the region of interest selection was improved by reconstructing co-registered Doppler images. This study will be continued in order to obtain quantitative tissue properties using US-guided PAT.
Download or read book Ultrasound Guided Diffuse Optical Tomography for Breast Cancer Diagnosis written by K. M. Shihab Uddin and published by . This book was released on 2020 with total page 113 pages. Available in PDF, EPUB and Kindle. Book excerpt: According to National Breast Cancer Society, one in every eight women in United States is diagnosed with breast cancer in her lifetime. American Cancer Society recommends a semi-annual breast-cancer screening for every woman which can be heavily facilitated by the availability of low-cost, non-invasive diagnostic method with good sensitivity and penetration depth. Ultrasound (US) guided Diffuse Optical Tomography (US-guided DOT) has been explored as a breast-cancer diagnostic and screening tool over the past two decades. It has demonstrated a great potential for breast-cancer diagnosis, treatment monitoring and chemotherapy-response prediction. In this imaging method, optical measurements of four different wavelengths are used to reconstruct unknown optical absorption maps which are then used to calculate the hemoglobin concentration of the US-visible lesion. This dissertation focuses on algorithm development for robust data processing, imaging reconstruction and optimal breast cancer diagnostic strategy development in DOT. The inverse problem in DOT is ill-posed, ill-conditioned, and underdetermined. This makes the task of image reconstruction challenging, and thus regularization-based method need to be employed. In this dissertation, a simple two-step reconstruction method that can produce accurate image estimates in DOT is proposed and investigated. In the first step, a truncated Moore-Penrose Pseudoinverse solution is computed to obtain a preliminary estimate of the image. This estimate can be reliably determined from the measured data; subsequently, this preliminary estimate is incorporated into the design of a penalized least squares estimator that is employed to compute the final image estimate. Using physical phantoms, the proposed method was demonstrated to yield more accurate reconstruction compared to other conventional reconstruction methods. The method was also evaluated with clinical data that included 10 benign and 10 malignant cases. The capability of reconstructing high contrast malignant lesions improved by the use of the proposed method.Reconstructed absorption maps are prone to image artifacts from outliers in measurement data from tissue heterogeneity, bad coupling between tissue and light guides, and motion by patient or operator. In this dissertation, a new automated iterative perturbation correction algorithm is proposed to reduce image artifacts based on the structural similarity index (SSIM)) of absorption maps of four optical wavelengths. The SSIM was calculated for each wavelength to assess its similarity with other wavelengths. Absorption map was iteratively reconstructed and projected back into measurement space to quantify projection error. Outlier measurements with highest projection errors were iteratively removed until all wavelength images were structurally similar with SSIM values greater than a threshold. Clinical data demonstrated statistically significant improvement in image artifact reduction.US guidance with DOT helps to reduce false positive rate and hence reduce number of unnecessary biopsies. However, DOT data processing and image reconstruction speed remains slow compared to real-time US. Real-time or near real time diagnosis with DOT is an important step toward the clinical translation of the US-guided DOT. In this dissertation, to address this important need, we present a two-stage diagnostic strategy that is computationally efficient and accurate. In the first stage, benign lesions are identified in near real-time by use of a random forest classifier acting on the DOT measurements and radiologists' US diagnostic scores. The lesions that cannot be reliably classified by the random forest classifier will be passed on to the image reconstruction stage. Functional information from the reconstructed hemoglobin concentrations is used by a Support Vector Machine (SVM) classifier for diagnosis in the second stage. This two-step classification approach that combines both perturbation data and functional features results in improved classification, as quantified using the receiver operating characteristic (ROC) curve. Using this two-step approach, area under the ROC curve (AUC) is 0.937 ± 0.009 with sensitivity of 91.4% and specificity of 85.7%. While using functional features and US score, AUC is 0.892 ± 0.027 with sensitivity of 90.2% and specificity of 74.5%. The specificity increased by more than 10% due to the implementation of the random forest classifier.
Download or read book Alternative Breast Imaging written by Keith D. Paulsen and published by Springer Science & Business Media. This book was released on 2005 with total page 280 pages. Available in PDF, EPUB and Kindle. Book excerpt: Medical imaging has been transformed over the past 30 years by the advent of computerized tomography (CT), magnetic resonance imaging (MRI), and various advances in x-ray and ultrasonic techniques. An enabling force behind this progress has been the (so far) exponentially increasing power of computers, which has made it practical to explore fundamentally new approaches. In particular, what our group terms "model-based" modalities-which produce tissue property images from data using nonlinear, iterative numerical modeling techniques-have become increasingly feasible. Alternative Breast Imaging: Four Model-Based Approaches explores our research on four such modalities, particularly with regard to imaging of the breast: (1) MR elastography (MRE), (2) electrical impedance spectroscopy (EIS), (3) microwave imaging spectroscopy (MIS), and (4) near infrared spectroscopic imaging (NIS). Chapter 1 introduces the present state of breast imaging and discusses how our alternative modalities can contribute to the field. Chapter 2 looks at the computational common ground shared by all four modalities. Chapters 2 through 10 are devoted to the four modalities, with each modality being discussed first in a theory chapter and then in an implementation-and-results chapter. The eleventh and final chapter discusses statistical methods for image analysis in the context of these four alternative imaging modalities. Imaging for the detection of breast cancer is a particularly interesting and relevant application of the four imaging modalities discussed in this book. Breast cancer is an extremely common health problem for women; the National Cancer Institute estimates that one in eight US women will develop breast cancer at least once in her lifetime. Yet the efficacy of the standard (and notoriously uncomfortable) early-detection test, the x-ray mammogram, has been disputed of late, especially for younger women. Conditions are thus ripe for the development of affordable techniques that replace or complement mammography. The breast is both anatomically accessible and small enough that the computing power required to model it, is affordable. Alternative Breast Imaging: Four Model-Based Approaches is structured to meet the needs of a professional audience composed of researchers and practitioners in industry. This book is also suitable for graduate-level students in computer science, electrical engineering and biomedical imaging.
Download or read book Physics of Mammographic Imaging written by Mia K. Markey and published by CRC Press. This book was released on 2012-11-09 with total page 321 pages. Available in PDF, EPUB and Kindle. Book excerpt: Due to the increasing number of digital mammograms and the advent of new kinds of three-dimensional x-ray and other forms of medical imaging, mammography is undergoing a dramatic change. To meet their responsibilities, medical physicists must constantly renew their knowledge of advances in medical imaging or radiation therapy, and must be prepared to function at the intersection of these two fields. Physics of Mammographic Imaging gives an overview on the current role and future potential of new alternatives to mammography in the context of clinical need, complementary approaches, and ongoing research. This book provides comprehensive coverage on the fundamentals of image formation, image interpretation, analysis, and modeling. It discusses the use of mammographic imaging in the detection, diagnosis, treatment planning, and monitoring of breast cancer. Expert authors give a balanced summary of core topics such as digital mammography, contrast-enhanced mammography, stereomammography, breast tomosynthesis, and breast CT. The book highlights the use of mammographic imaging with complementary breast imaging modalities such as ultrasound, MRI, and nuclear medicine techniques. It discusses critical issues such as computer-aided diagnosis, perception, and quality assurance. This is an exciting time in the development of medical imaging, with many new technologies poised to make a substantial impact on breast cancer care. This book will help researchers and students get up to speed on crucial developments and contribute to future advances in the field.
Download or read book Profilometry for Diffuse Optical Tomography Breast Imaging System written by Long Xie and published by . This book was released on 2013 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Correlations Among Ultrasound Guided Diffuse Optical Tomography Microvessel Density and Breast Cancer Prognosis written by and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Methods for Improving the Reconstruction of Diffuse Optical Tomography for Breast Cancer Detection written by Murad Mohsen Althobaiti and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Diffuse Optical Tomography written by Huabei Jiang and published by CRC Press. This book was released on 2017 with total page 376 pages. Available in PDF, EPUB and Kindle. Book excerpt: Written by an authority involved in the field since its nascent stages, Diffuse Optical Tomography: Principles and Applications is a long-awaited profile of a revolutionary imaging method. Diffuse Optical Tomography (DOT) provides spatial distributions of intrinsic tissue optical properties or molecular contrast agents through model-based reconstruction algorithms using NIR measurements along or near the boundary of tissue. Despite the practical value of DOT, many engineers from electrical or applied mathematics backgrounds do not have a sufficient understanding of its vast clinical applications and portability value, or its uncommon advantages as a tool for obtaining functional, cellular, and molecular parameters. A collection of the author�s research and experience, this book fuses historical perspective and experiential anecdotes with fundamental principles and vital technical information needed to successfully apply this technology�particularly in medical imaging. This reference finally outlines how to use DOT to create experimental image systems and adapt the results of laboratory studies for use in clinical applications including: Early-stage detection of breast tumors and prostate cancer "Real-time" functional brain imaging Joint imaging to treat progressive diseases such as arthritis Monitoring of tumor response New contrast mechanisms and multimodality methods This book covers almost every aspect of DOT�including reconstruction algorithms based on nonlinear iterative Newton methods, instrumentation and calibration methods in both continuous-wave and frequency domains, and important issues of imaging contrast and spatial resolution. It also addresses phantom experiments and the development of various image-enhancing schemes, and it describes reconstruction methods based on contrast agents and fluorescence DOT. Offering a concise description of the particular problems involved in optical tomography, this reference illustrates DOT�s fundamental foundations and the principle of image reconstruction. It thoroughly explores computational methods, forward mathematical models, and inverse strategies, clearly illustrating solutions to key equations.
Download or read book Optimizing Near infrared Spectral Tomography for Diagnostic Imaging and Monitoring of Breast Cancer Treatment written by Yan Zhao and published by . This book was released on 2017 with total page 332 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Near-infrared spectral tomography (NIRST) has been intensively investigated for clinical application in breast imaging, by providing functional information about physiologically related biomarkers such as oxy- and deoxy-hemoglobin, water, lipid and scatter component. In this thesis, a series of studies on system development and reconstruction algorithm were completed to improve the imaging quality of MR-guide NIRST and to predicate breast cancer response to neo-adjuvant chemotherapy. To optimize image recovery which maximizes difference between malignant and benign lesions, non-linear iterative reconstructions of MR-Guided NISRT images were recovered using an L-curve based algorithm, and applied to clinical trial data. The statistical analyses have shown that the new approach dramatically improved the statistical significance for differentiating malignant from benign lesions. While MRI guide NIRST has been utilized to detect breast cancer, NIRST is also used to predicate and monitor breast tumor responses in patients with locally advanced breast cancer undergoing neoadjuvant treatment. Based on an existing hybrid NIRST system developed at Dartmouth, a compact and portable NIRST system has been developed for imaging patients in the infusion unit while patients are awaiting or undergoing infusion. This system can acquire frequency-domain and continuous-wave data simultaneously at 12 wavelengths in the wavelength range of 660nm to 1064nm. Novel soft gel based homogenous and heterogamous tissue-mimicking phantoms with sphere-shape inclusions have been developed, to mimic human breasts. The phantom experiments indicate that the reconstructed optical images highly depend on the position of imaging plane, especially in the case of small inclusions. Tomographic images of breast collagen content have been recovered for the first time, and image reconstruction approaches with and without collagen content included have been validated in simulation studies, which indicate that including collagen content into the reconstruction procedure can significantly reduce the overestimation in total hemoglobin, water and lipid, and underestimates in oxygen saturation. A group of 10 normal subjects were imaged, and significantly higher (p
Download or read book Computerized Ultrasound Risk Evaluation CURE System written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Our Computerized Ultrasound Risk Evaluation (CURE) system has been developed to the engineering prototype stage and generated unique data sets of both transmission and reflection ultrasound (US). This paper will help define the clinical underpinnings of the developmental process and interpret the imaging results from a similar perspective. The CURE project was designed to incorporate numerous diagnostic parameters to improve upon two major areas of early breast cancer detection. CURE may provide improved tissue characterization of breast masses and reliable detection of abnormal microcalcifications found in some breast cancers and ductal carcinoma in situ (DCIS). Current breast US is limited to mass evaluation, whereas mammography also detects and guides biopsy of malignant calcifications. Screening with CURE remains a distant goal, but improved follow-up of mammographic abnormalities may represent a feasible breakthrough. Improved tissue characterization could result in reduction of the estimated one million benign biopsies each year in the United States, costing up to several billion dollars. Most breast calcifications are benign and comprise-80% of stereotactic biopsies guided by mammography. Ultrasound has the capability of finding some groups of calcifications, but further improvements in resolution should also address tissue characterization to define the soft tissue filling of ducts by DCIS. In this manner, CURE may be able to more accurately identify the malignant calcifications associated with progression of DCIS or early cancers. Currently, high-resolution US images of the breast are performed in the reflection mode at higher frequencies, which also limits depth of penetration. Reconstruction of reflection ultrasound images relies upon acoustic impedance differences in the tissue and includes only direct backscatter of the ultrasound signal. Resolution and tissue contrast of current US continues to improve with denser transducer arrays and image processing, but the operator dependent nature of using a moveable transducer head remains a significant problem for thorough coverage of the entire breast. We have therefore undertaken the development of a whole breast (i.e., including auxiliary tail) system, with improved resolution and tissue characterization abilities. The extensive ultrasound physics considerations, engineering, materials process development and subsequent algorithm reconstruction are beyond the scope of this initial paper. The proprietary nature of these processes will be forthcoming as the intellectual property is fully secured. We will focus here on the imaging outcomes as they apply to eventual expansion into clinical use.
Download or read book Optical Imaging of Breast Cancers written by Yan Xu and published by . This book was released on 2013 with total page 334 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Multimodal Breast Cancer Imaging System Using Coregistered Dynamic Diffuse Optical Tomography and Digital Breast Tomosynthesis written by Bernhard B. Zimmermann and published by . This book was released on 2017 with total page 102 pages. Available in PDF, EPUB and Kindle. Book excerpt: Diffuse optical tomography (DOT) is an emerging noninvasive functional imaging method for breast cancer diagnosis and neoadjuvant chemotherapy monitoring. In particular, the multimodal approach of combining DOT with x-ray digital breast tomosynthesis (DBT) is especially synergistic as DBT prior information can be used to enhance the DOT reconstruction. DOT, in turn, provides a functional information overlay onto the mammographic images, increasing sensitivity and specificity to cancer pathology. We describe a dynamic DOT apparatus designed for tight integration with commercial DBT scanners and providing a fast (1 Hz+) image acquisition rate to enable tracking of hemodynamic changes induced by the mammographic breast compression. The most significant advance enabling fast acquisition was the design and construction of a direct analog-to-digital conversion frequency-domain near-infrared spectroscopy (FD-NIRS) component. It achieves simultaneous dual wavelength operation at 685 nm and 830 nm by concurrent 67.5 MHz and 75 MHz frequency modulation of each laser source, respectively, followed by digitization using a high-speed analog to digital converter and real-time hybrid FPGA-assisted demodulation by discrete Fourier transform (DFT). The overall DOT system integrates 96 CW-NIRS and 24 FD-NIRS source locations, as well as 32 CW-NIRS and 20 FD-NIRS detection locations into low-profile plates that mate to the DBT compression paddle and x-ray detector cover, respectively. The plates and the embedded optical fibers are made of plastic to minimize x-ray absorption and thus allow true simultaneous acquisition of the DBT image. We first characterize each major system component individually, and then demonstrate overall performance using static and dynamic tissue-like phantoms, as well as in vivo images acquired from the pool of patients recalled for breast biopsies at the Massachusetts General Hospital Breast Imaging Division.
Download or read book Biophotonics for Medical Applications written by Igor Meglinski and published by Elsevier. This book was released on 2015-06-29 with total page 402 pages. Available in PDF, EPUB and Kindle. Book excerpt: Biophotonics for Medical Applications presents information on the interface between laser optics and cell biology/medicine. The book discusses the development and application of photonic techniques that aid the diagnosis and therapeutics of biological tissues in both healthy and diseased states. Chapters cover the fundamental technologies used in biophotonics and a wide range of therapeutic and diagnostic applications. - Presents information on the interface between laser optics and cell biology/medicine - Discusses the development and application of photonic techniques which aid the diagnosis and therapeutics of biological tissues in both healthy and diseased states - Presents the fundamental technologies used in biophotonics and a wide range of therapeutic and diagnostic applications
Download or read book Mammography and Beyond written by National Research Council and published by National Academies Press. This book was released on 2001-07-23 with total page 311 pages. Available in PDF, EPUB and Kindle. Book excerpt: Each year more than 180,000 new cases of breast cancer are diagnosed in women in the U.S. If cancer is detected when small and local, treatment options are less dangerous, intrusive, and costly-and more likely to lead to a cure. Yet those simple facts belie the complexity of developing and disseminating acceptable techniques for breast cancer diagnosis. Even the most exciting new technologies remain clouded with uncertainty. Mammography and Beyond provides a comprehensive and up-to-date perspective on the state of breast cancer screening and diagnosis and recommends steps for developing the most reliable breast cancer detection methods possible. This book reviews the dramatic expansion of breast cancer awareness and screening, examining the capabilities and limitations of current and emerging technologies for breast cancer detection and their effectiveness at actually reducing deaths. The committee discusses issues including national policy toward breast cancer detection, roles of public and private agencies, problems in determining the success of a technique, availability of detection methods to specific populations of women, women's experience during the detection process, cost-benefit analyses, and more. Examining current practices and specifying research and other needs, Mammography and Beyond will be an indispensable resource to policy makers, public health officials, medical practitioners, researchers, women's health advocates, and concerned women and their families.
Download or read book Photons Plus Ultrasound written by Alexander A. Oraevsky and published by . This book was released on 2012 with total page 808 pages. Available in PDF, EPUB and Kindle. Book excerpt: Includes Proceedings Vol. 7821
Download or read book Photoacoustic Tomography written by Minghua Xu and published by CRC PressI Llc. This book was released on 2014-09-30 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt:
