Differentiation among Basal Cell Carcinoma, Benign Lesions, and Normal Skin using Electric Impedance

This paper presents a preliminary study showing the diagnostic potential of electrical impedance to detect basal cell carcinoma (BCC). Electrical impedance was measured in vivo from 1 kHz to 1 MHz on 24 human subjects over BCC (19 lesions), over benign tumors (11 lesions), and over normal skin (all 24 patients). Lesions ranged from 2-15 mm in diameter. Indexes based on the magnitude (MIX), phase (PIX), real-part (RIX) and imaginary-part (IMIX) of impedance were calculated for each measurement. Significant differences were found between measurements over BCC, benign lesions and normal skin for indexes MIX, PIX, and IMIX (P = 0.04 to P = 7 x 107. Indexes were generally smaller for measurements of BCC than for benign lesions or normal skin. Differences were not a result of differences in the patient\u27\u27s age or the measurement location. The large size of our measurement electrode (10 mm) probably limited our ability to differentiate lesions because significant amounts of normal skin were included in each lesion measurement. A linear regression fit of data with tumor size suggests that a smaller probe or more sophisticated analysis techniques may improve differentiation. Results suggest that electrical impedance could be used to provide rapid and noninvasive differentiation of BCC from similar looking benign lesions

High Resolution Imaging and Digital Characterization of Skin Pathology By Scanning Acoustic Microscopy

Skin cancer represents the most common worldwide malignancy with a widely varying prognosis. Most of the diagnostic tools used for skin imaging are still limited to provide a definite diagnosis of skin cancer, especially melanoma. Easy access to the skin to biopsy and excision made skin underexplored using ultrasonic diagnostic imaging. Given the fact that speed of sound and acoustic impedance are related to elastic modulus, quantitative acoustic microscopy shows great potential as a useful tool for skin cancer diagnosis. The high-frequency acoustic microscopy method was used to evaluate properties of the cancer lesions for melanoma, basal cell carcinoma, and squamous cell carcinoma. The algorithm for quantitative characterization of individual cells in the histological slices has been developed. All cancer cells regardless of the cancer type have lower sound speed comparing to healthy skin cells. The melanoma cells have the lowest values of sound speed (1360 ± 50 m/s) comparing to basal cell carcinoma and squamous cell carcinoma. It was demonstrated on thickly cut skin specimens that melanoma lesions have lower acoustic impedance compared to healthy skin. These findings may become the basis for a new ultrasonic method for melanoma diagnosis or for margin status verification during the surgery helting to reduce the mortality rate from melanoma and improve healthcare in Canada and worldwide

Microwave Reflectometry as a Novel Diagnostic Method for Detection of Skin Cancers

More than one million people are diagnosed with skin cancer each year in the United States and more than ten thousand people die from the disease. Currently, there are some methods for early detection of skin cancers, like visual inspection, but improvements are needed. This paper presents a method involving microwave reflectometry as a diagnostic tool for detection of skin cancers. The results of measurements and simulations for normal and wet skin have been shown to distinguish among skin samples with different properties. Microwave measurements from lesions have also been presented which are used to distinguish between cancerous and benign lesions

Применение биоимендансной спектроскопии в лучевой терапии

Cancer cells exhibit altered local dielectric properties compared to normal cells because of the difference in shape, size and orientation. These properties are measurable as a difference in electrical conductance using electrical impedance spectroscopy. Electrical impedance is one of the most often used parameters for characterizing material properties, especially in biomedical applications. The electrical parameters of the tissues could be used to distinguish the tissue’s status. Changes in electrical properties at different frequency rate reveal that there exist differences between conductivity of non-irradiated and irradiated tissues

Microwave Reflectometry As a Novel Diagnostic Tool for Detection of Skin Cancers

More than 1 000 000 people are diagnosed with skin cancer each year in the United States, and more than 10 000 people die from the disease. Methods such as visual inspection and dermoscopy are available for early detection of skin cancers, but improvement in accuracy is needed. This paper investigates the use of microwave reflectometry as a potential diagnostic tool for detection of skin cancers. Open-ended coaxial probes were used to measure microwave properties of skin. The influences of measurement parameters such as probe application pressure, power level, and variation in reflection properties of skin with location and hydration were investigated. Using an available electromagnetic formulation, providing for the reflection properties of a layered dielectric structure irradiated by a coaxial probe, measurement and simulation results were compared. The results of the measurements and simulations for normal and moistened skin show that the water content of normal skin and benign and malignant lesions may cause significant differences among their reflection properties and subsequently render a malignant lesion detectable. The results of microwave measurements performed on human subjects are also presented, which show the potential of this technique to distinguish between cancerous and benign lesions

Improving Clinical Diagnosis of Melanocytic Skin Lesions by Raman Spectroscopy

High-quality Raman signals from melanocytic lesions compatible with a possible clinical application have not been demonstrated yet. The objectives of the work described in this thesis were: I: The development of a Raman spectroscopic prototype for objective and fast assessment of melanocytic skin lesions clinically suspicious for melanoma; II: Identification of the main spectroscopic features of melanoma and benign melanocytic lesions suspicious for melanoma; III: Assessment of the feasibility of Raman spectroscopy as an adjunct technique to improve clinical diagnosis of melanocytic skin lesions

Development of a novel probe integrated with a micro-structured impedance sensor for the detection of breast cancer

The work described in this thesis focuses on the development of an innovative bioimpedance device for the detection of breast cancer using electrical impedance as the detection method. The ability for clinicians to detect and treat cancerous lesions as early as possible results in improved patient outcomes and can reduce the severity of the treatment the patient has to undergo. Therefore, new technology and devices are continually required to improve the specificity and sensitivity of the accepted detection methods. The gold standard for breast cancer detection is digital x-ray mammography but it has some significant downsides associated with it. The development of an adjunct technology to aid in the detection of breast cancers could represent a significant patient and economic benefit. In this project silicon substrates were pattern with two gold microelectrodes that allowed electrical impedance measurements to be recorded from intact tissue structures. These probes were tested and characterised using a range of in vitro and ex vivo experiments. The end application of this novel sensor device was in a first-in-human clinical trial. The initial results of this study showed that the silicon impedance device was capable of differentiating between normal and abnormal (benign and cancerous) breast tissue. The mean separation between the two tissue types 4,340 Ω with p < 0.001. The cancer type and grade at the site of the probe recordings was confirmed histologically and correlated with the electrical impedance measurements to determine if the different subtypes of cancer could each be differentiated. The results presented in this thesis showed that the novel impedance device demonstrated excellent electrochemical recording potential; was biocompatible with the growth of cultured cell lines and was capable of differentiating between intact biological tissues. The results outlined in this thesis demonstrate the potential feasibility of using electrical impedance for the differentiation of biological tissue samples. The novelty of this thesis is in the development of a new method of tissue determination with an application in breast cancer detection

Nerve localization techniques for peripheral nerve block and possible future directions

Ultrasound guidance is now a standard nerve localization technique for peripheral nerve block (PNB). Ultrasonography allows simultaneous visualization of the target nerve, needle, local anesthetic injectate and surrounding anatomical structures. Accurate deposition of local anesthetic next to the nerve is essential to the success of the nerve block procedure. Unfortunately, due to limitations in the visibility of both needle tip and nerve surface, the precise relationship between needle tip and target nerve is unknown at the moment of injection. Importantly, nerve injury may result both from an inappropriately placed needle tip and inappropriately placed local anesthetic. The relationship between the block needle tip and target nerve is of paramount importance to the safe conduct of peripheral nerve block. This review summarizes the evolution of nerve localization in regional anesthesia, characterizes a problem faced by clinicians in performing ultrasound guided nerve block and explores the potential technological solutions to this problem

Breast Cancer and Breast Reconstruction

This book has been contrived to gather recent data on a common health problem. As breast cancer imposes a heavy burden for society due to its psychological, social and economic consequences, every step to broaden our understanding is a worthy task. The aim of this book is to provide some insights on this subject through the information given on new perspectives in genetics and diagnosis, exposed in the section on oncologic issues, as well as on recent topics on surgical treatment, presented in the sections on breast conservative and breast reconstructive surgery

Microscopy and Analysis

Microscopes represent tools of the utmost importance for a wide range of disciplines. Without them, it would have been impossible to stand where we stand today in terms of understanding the structure and functions of organelles and cells, tissue composition and metabolism, or the causes behind various pathologies and their progression. Our knowledge on basic and advanced materials is also intimately intertwined to the realm of microscopy, and progress in key fields of micro- and nanotechnologies critically depends on high-resolution imaging systems. This volume includes a series of chapters that address highly significant scientific subjects from diverse areas of microscopy and analysis. Authoritative voices in their fields present in this volume their work or review recent trends, concepts, and applications, in a manner that is accessible to a broad readership audience from both within and outside their specialist area