Search results for "SPECTRA"
showing 10 items of 3542 documents
Multispectral imaging of pigmented and vascular cutaneous malformations: the influence of laser treatment
2010
The paper investigates influence and efficacy of laser therapy on pigmented and vascular cutaneous malformations by multispectral imaging technique. Parameter mapping of skin pigmented and vascular lesions and monitoring of the laser therapy efficacy are performed by multispectral imaging in wavelength range 450-700nm by scanning step - 10nm. Parameter maps of the oxyhemoglobin deoxyhemoglobin and melanin derived from the images are presented. Possibility of laser therapy efficacy monitoring by comparison of the parameter maps before and after laser treatment has been demonstrated. As both cutaneous pigmented and vascular malformations are commonly found lesions, the parameter mapping would…
Benign — A typical nevi discrimination using diffuse reflectance and fluorescence multispectral imaging system
2015
Early diagnostics of skin cancer is of interest for dermatologists. Atypical nevi are not considered to be malignant, but are suspects that should be detected and monitored over time. The multispectral imaging system Nuance operating in spectral range 450–950 nm was adapted for clinical in vivo measurements in diffuse reflectance and fluorescence mode. Mean and standard deviation values of optical density and fluorescence intensity were extracted from segmented pigmented lesions (21 benign and 26 atypical nevi) and used for further analysis. It was possible to achieve 62% sensitivity and 67% specificity for discrimination between atypical and benign lesions using averaged fluorescence mean …
Hyperspectral imaging reveals spectral differences and can distinguish malignant melanoma from pigmented basal cell carcinomas : A pilot study
2021
Pigmented basal cell carcinomas can be difficult to distinguish from melanocytic tumours. Hyperspectral imaging is a non-invasive imaging technique that measures the reflectance spectra of skin in vivo. The aim of this prospective pilot study was to use a convolutional neural network classifier in hyperspectral images for differential diagnosis between pigmented basal cell carcinomas and melanoma. A total of 26 pigmented lesions (10 pigmented basal cell carcinomas, 12 melanomas in situ, 4 invasive melanomas) were imaged with hyperspectral imaging and excised for histopathological diagnosis. For 2-class classifier (melanocytic tumours vs pigmented basal cell carcinomas) using the majority of…
A multispectral imaging approach for diagnostics of skin pathologies
2013
Noninvasive multispectral imaging method was applied for different skin pathology such as nevus, basal cell carcinoma, and melanoma diagnostics. Developed melanoma diagnostic parameter, using three spectral bands (540 nm, 650 nm and 950 nm), was calculated for nevus, melanoma and basal cell carcinoma. Simple multispectral diagnostic device was established and applied for skin assessment. Development and application of multispectral diagnostics method described further in this article.
Evaluation of a multispectral diffuse optical spectroscopy device for assessment of cardiometabolic risk related alterations of body composition
2013
Cardiometabolic diseases encompass a combination of conditions which lead to an increase in the risk of cardiovascular disease and diabetes. With the increasing percentage of the population becoming overweight, it is important to diagnose when the excess adipose tissue becomes malign. The development of a safe, mobile, non-invasive method that would be easy to perform, and low-cost, but also would offer an accurate assessment of subcutaneous adipose tissue (SAT) both in lean and in obese persons is required. A prototype device using an optical method for measurement of the SAT in vivo has been developed, it contains multiple LEDs with four wavelengths (660nm, 780nm, 870nm, 940nm) distribute…
Melanoma-nevus differentiation by multispectral imaging
2011
A clinical trial on multi-spectral imaging of malignant and non-malignant skin pathologies comprising 22 melanomas and 59 pigmented nevi was performed in Latvian Oncology Center. Analysis of data obtained in the spectral range 450–950 nm using multispectral camera have led to a novel image processing algorithm capable to distinguish melanoma from pigmented nevi and different areas of activity of melanoma. The proposed methodology and potential clinical applications are discussed.
Application of principal component analysis to multispectral imaging data for evaluation of pigmented skin lesions
2013
Non-invasive and fast primary diagnostics of pigmented skin lesions is required due to frequent incidence of skin cancer – melanoma. Diagnostic potential of principal component analysis (PCA) for distant skin melanoma recognition is discussed. Processing of the measured clinical multi-spectral images (31 melanomas and 94 nonmalignant pigmented lesions) in the wavelength range of 450-950 nm by means of PCA resulted in 87 % sensitivity and 78 % specificity for separation between malignant melanomas and pigmented nevi.
Evaluation of Skin Vascular Malformations’ Laser Treatment by RGB and Multi-spectral Imaging
2012
RGB imaging system for mapping and monitoring of hemoglobin changes in skin has been tested for evaluation of vascular malformations’ laser treatment. The multi-spectral imaging system was used as the reference.
Clinical evaluation of melanomas and common nevi by spectral imaging
2012
A clinical trial on multi-spectral imaging of malignant and non-malignant skin pathologies comprising 17 melanomas and 65 pigmented common nevi was performed. Optical density data of skin pathologies were obtained in the spectral range 450-950 nm using the multispectral camera Nuance EX. An image parameter and maps capable of distinguishing melanoma from pigmented nevi were proposed. The diagnostic criterion is based on skin optical density differences at three fixed wavelengths: 540nm, 650nm and 950nm. The sensitivity and specificity of this method were estimated to be 94% and 89%, respectively. The proposed methodology and potential clinical applications are discussed.
Measurement of jet suppression in central Pb–Pb collisions at √sNN = 2.76 TeV
2015
The transverse momentum (pT) spectrum and nuclear modification factor (RAA) of reconstructed jets in 0–10% and 10–30% central Pb–Pb collisions at √sNN = 2.76 TeV were measured. Jets were reconstructed using the anti-kT jet algorithm with a resolution parameter of R = 0.2 from charged and neutral particles, utilizing the ALICE tracking detectors and Electromagnetic Calorimeter (EMCal). The jet pT spectra are reported in the pseudorapidity interval of |ηjet| 5 GeV/c to suppress jets constructed from the combinatorial background in Pb–Pb collisions. The leading charged particle requirement applied to jet spectra both in pp and Pb– Pb collisions had a negligible effect on the RAA. The nuclear m…