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Analysis of morphological changes of the peritoneal membrane is an essential part of animal studies when investigating molecular mechanisms involved in the development of peritoneal fibrosis or testing the effects of potential therapeutic agents. Current methods, such as histology and immunohistochemistry, require time consuming sample processing and analysis and result in limited spatial information. In this paper we present a new method to evaluate structural and chemical changes in an animal model of peritoneal fibrosis that is based on hyperspectral imaging and a model of light transport. The method is able to distinguish between healthy and diseased subjects based on morphological as well as physiological parameters such as blood and scattering parameters. Furthermore, it enables evaluation of changes, such as degree of inflammation and fibrosis, that are closely related to histological findings.

Imaging of blood vessel structure in combination with functional information about blood oxygenation can be important in characterizing many different health conditions in which the growth of new vessels contributes to the overall condition. In this paper, we present a method for extracting comprehensive maps of the vasculature from hyperspectral images that include tissue and vascular oxygenation. We also show results from a preclinical study of peritonitis in mice. First, we analyze hyperspectral images using Beer-Lambert exponential attenuation law to obtain maps of hemoglobin species throughout the sample. We then use an automatic segmentation algorithm to extract blood vessels from the hemoglobin map and combine them into a vascular structure-oxygenation map. We apply this methodology to a series of hyperspectral images of the abdominal wall of mice with and without induced peritonitis. Peritonitis is an inflammation of peritoneum that leads, if untreated, to complications such as peritoneal sclerosis and even death. Characteristic inflammatory response can also be accompanied by changes in vasculature, such as neoangiogenesis. We demonstrate a potential application of the proposed segmentation and processing method by introducing an abnormal tissue fraction metric that quantifies the amount of tissue that deviates from the average values of healthy controls. It is shown that the proposed metric successfully discriminates between healthy control subjects and model subjects with induced peritonitis and has a high statistical significance.

Background and Objectives The aim of this study was to determine the temperature depth profiles induced in human skin in vivo by using a pulsed 975 nm diode laser (with 5 ms pulse duration) and compare them with those induced by the more common 532 nm (KTP) and 1,064 nm (Nd:YAG) lasers. Quantitative assessment of the energy deposition characteristics in human skin at 975 nm should help design of safe and effective treatment protocols when using such lasers. Study Design/Materials and Methods Temperature depth profiles induced in the human skin by the three lasers were determined using pulsed photothermal radiometry (PPTR). This technique involves time‐resolved measurement of mid‐infrared emission from the irradiated test site and reconstruction of the laser‐induced temperature profiles using an earlier developed optimization algorithm. Measurements were performed on volar sides of the forearms in seven volunteers with healthy skin. At irradiation spot diameters of 3–4 mm, the radiant exposures were 0.24, 0.36, and 5.7 J/cm2 for the 975, 532, and 1,064 nm lasers, respectively. Results Upon normalization to the same radiant exposure of 1 J/cm 2, the assessed maximum temperature rise in the epidermis averaged 0.8 °C for the 975 nm laser, 7.4 °C for the 532 nm, and 0.6 °C for the 1,064 nm laser. The characteristic subsurface depth to which 50% of the absorbed laser energy was deposited was on average 0.31 mm at 975 nm irradiation, and slightly deeper at 1,064 nm, and 0.15 mm at 532 nm. The experimentally obtained relations were reproduced in a dedicated numerical simulation. Conclusions The assessed energy deposition characteristics show that the pulsed 975 nm diode laser is very suitable for controlled heating of the upper dermis as required, for example, for nonablative skin rejuvenation. The risks of nonselective overheating of the epidermis and subcutis are significantly reduced in comparison with irradiation at 532 and 1,064 nm, respectively. Lasers Surg. Med. © 2019 Wiley Periodicals, Inc.

Understanding tumors and their microenvironment are essential for successful and accurate disease diagnosis. Tissue physiology and morphology are altered in

. Significance: Hyperspectral imaging (HSI) has emerged as a promising optical technique. Besides optical properties of a sample, other sample physical properties also affect the recorded images. They are significantly affected by the sample curvature and sample surface to camera distance. A correction method to reduce the artifacts is necessary to reliably extract sample properties. Aim: Our aim is to correct hyperspectral images using the three-dimensional (3D) surface data and assess how the correction affects the extracted sample properties. Approach: We propose the combination of HSI and 3D profilometry to correct the images using the Lambert cosine law. The feasibility of the correction method is presented first on hemispherical tissue phantoms and next on human hands before, during, and after the vascular occlusion test (VOT). Results: Seven different phantoms with known optical properties were created and imaged with a hyperspectral system. The correction method worked up to 60 deg inclination angle, whereas for uncorrected images the maximum angles were 20 deg. Imaging hands before, during, and after VOT shows good agreement between the expected and extracted skin physiological parameters. Conclusions: The correction method was successfully applied on the images of tissue phantoms of known optical properties and geometry and VOT. The proposed method could be applied to any reflectance optical imaging technique and should be used whenever the sample parameters need to be extracted from a curved surface sample.

Hyperspectral imaging (HSI) is a promising optical modality that is already being used in numerous applications. Further expansion of the capabilities of HSI depends on the modularity and versatility of the systems, which would, inter alia, incorporate profilometry, fluorescence imaging, and Raman spectroscopy while following a rigorous calibration and verification protocols, thus offering new insights into the studied samples as well as verifiable, quantitative measurement results applicable to the development of quantitative metrics. Considering these objectives, we developed a custom-made laboratory HSI system geared toward biomedical applications. In this report, we describe the design, along with calibration, characterization, and verification protocols needed to establish such systems, with the overall goal of standardization. As an additional novelty, our HSI system uses a custom-built broadband LED-based light source for reflectance imaging, which is particularly important for biomedical applications due to the elimination of sample heating. Three examples illustrating the utility and advantages of the integrated system in biomedical applications are shown. Our attempt presents both the development of a custom-based laboratory HSI system with novel LED light source as well as a framework which may improve technological standards in HSI system design.