Hyperspectral imaging with machine learning for in vivo skin carcinoma margin assessment: a preliminary study.

Surgical excision is the most effective treatment of skin carcinomas (basal cell carcinoma or squamous cell carcinoma). Preoperative assessment of tumoral margins plays a decisive role for a successful result. The aim of this work was to evaluate the possibility that hyperspectral imaging could become a valuable tool in solving this problem.

Comparative analysis of denoising techniques in burn depth discrimination from burn hyperspectral images.

This study analyzes and compares the performance of five denoising techniques (Lee filter, gamma filter, principal component analysis, maximum noise fraction, and wavelet transform) in order to identify the most appropriate one that lead to the most accurate classification of burned tissue in hyperspectral images. Fifteen hyperspectral images of burned patients were acquired and denoising techniques were applied to each image. Spectral angle mapper classifier was used for data classification and the confusion matrix was used for quantitative evaluation of the performances of the denoising methods.

Mapping the Distribution of Melanin Concentration in Different Fitzpatrick Skin Types Using Hyperspectral Imaging Technique.

Measuring skin melanin concentration in order to assess skin phototype according to Fitzpatrick's classification is a constant research goal. In this study, a new approach for assessing skin melanin concentration based on hyperspectral imaging combined with an appropriate analytical model that exploits specific spectral bands to generate maps of melanin content distribution on different Fitzpatrick skin phototypes is presented. Hyperspectral images from the proximal inner side of the forearms of 51 young volunteers covering the first four classes of Fitzpatrick's phototypes were acquired using a hyperspectral imaging system.

Burn characterization using object-oriented hyperspectral image classification.

This paper presents a new approach based on hyperspectral imaging combined with an object-oriented classification method that allows the generation of burn depth classification maps facilitating easier characterization of burns. Hyperspectral images of 14 patients diagnosed with burns on the upper and lower limbs were acquired using a pushbroom hyperspectral imaging system. The images were analyzed using an object-oriented classification approach that uses objects with specific spectral, textural and spatial attributes as the minimum unit for classifying information.

New evidence from hyperspectral imaging analysis on the effect of photobiomodulation therapy on normal skin oxygenation.

The aim of this study was to assess the changes induced by photobiomodulation therapy in oxygenation of normal skin and underlying tissue using hyperspectral imaging combined with a chemometric regression approach. Eleven healthy adult volunteers were enrolled in this study. The dorsal side of the left hand of each subject was exposed to photobiomodulation therapy, while the correspondent side of the right hand was used as a control (placebo effect).

Automatic detection of basal cell carcinoma by hyperspectral imaging.

The purpose of this study was to test the ability of hyperspectral imaging (HSI) combined with unsupervised anomaly detectors to automatically differentiate basal cell carcinoma (BCC) from normal skin. Hyperspectral images of the face of a female patient with a BCC of the lower lip were acquired using a visible/near-infrared HSI system and two anomaly detection algorithms (Reed-Xiaoli and Reed-Xiaoli/Uniform Target hybrid anomaly detectors) were used to detect pathological tissue from normal skin. The results revealed that the receiver operating characteristic curve of the Reed-Xiaoli/Uniform Target hybrid detector was higher than that of the Reed-Xiaoli detector in the range of false positive rates between 0 and 0.

Object-oriented classification approach for bone metastasis mapping from whole-body bone scintigraphy.

Purpose: Whole-body bone scintigraphy is the most widely used method for detecting bone metastases in advanced cancer. However, its interpretation depends on the experience of the radiologist. Some automatic interpretation systems have been developed in order to improve diagnostic accuracy.

Computer-aided detection of bone metastasis in bone scintigraphy images using parallelepiped classification method.

Objective: Accurate diagnosis of metastatic tissue on bone scintigraphy images is of paramount importance in making treatment decisions. Although several automated systems have developed, more and better interpretation methods are still being sought. In the present study, a new modality for bone metastasis detection from bone scintigraphy images using parallelepiped classification (PC) as method for mapping the radionuclide distribution is presented.

Fractionated Irradiation in Photobiomodulation Therapy of Ankle Sprain.

Objective: The aim of this study was to test whether fractionated irradiation in photobiomodulation therapy enhances short-term recovery in patients with moderate severity ankle sprain.

Design: Nineteen patients were randomly assigned to one of two groups: one group receiving photobiomodulation therapy combined with the standard rest, icing, compression, and elevation treatment, or a group receiving only standard treatment. Group 1 patients were irradiated using a laser system (635 nm, 15 mW) according to a double-fractionated irradiation scheme consisting of two sessions (4.

Hyperspectral index-based metric for burn depth assessment.

Burn depth objective classification is of paramount importance for decision making and treatment. Despite the wide variety of burn depth assessment methods tested so far, none of them have gained wide clinical application. Here, we introduce a new approach for burn depth assessment based on hyperspectral imaging combined with a spectral index-based technique that exploits specific spectral bands to map skin areas with different burn degrees.

Simulated altitude exposure assessment by hyperspectral imaging.

Testing the human body’s reaction to hypoxia (including the one generated by high altitude) is important in aeronautic medicine. This paper presents a method of monitoring blood oxygenation during experimental hypoxia using hyperspectral imaging (HSI) and a spectral unmixing model based on a modified Beer–Lambert law. A total of 20 healthy volunteers (males) aged 25 to 60 years were included in this study.

An Analysis of Human Dorsal Hand Skin Texture Using Hyperspectral Imaging Technique for Assessing the Skin Aging Process.

Skin texture has become an important issue in recent research with applications in the cosmetic industry and medicine. In this paper, we analyzed the dependence of skin texture features on wavelength as well as on different parameters (age and gender) of human participants using grey-level co-occurrence matrix and hyperspectral imaging technique for a more accurate quantitative assessment of the aging process. A total of 42 healthy participants (men and women; age range, 20-70 years) was enrolled in this study.

Algorithm for mapping cutaneous tissue oxygen concentration using hyperspectral imaging.

The measurement of tissue oxygenation plays an important role in the diagnosis and therapeutic assessment of a large variety of diseases. Many different methods have been developed and are currently applied in clinical practice for the measurement of tissue oxygenation. Unfortunately, each of these methods has its own limitations.

Hyperspectral imaging-based wound analysis using mixture-tuned matched filtering classification method.

Hyperspectral imaging is a technology that is beginning to occupy an important place in medical research with good prospects in future clinical applications. We evaluated the role of hyperspectral imaging in association with a mixture-tuned matched filtering method in the characterization of open wounds. The methodology and the processing steps of the hyperspectral image that have been performed in order to obtain the most useful information about the wound are described in detail.

Characterization of burns using hyperspectral imaging technique - a preliminary study.

Surgical burn treatment depends on accurate estimation of burn depth. Many methods have been used to asses burns, but none has gained wide acceptance. Hyperspectral imaging technique has recently entered the medical research field with encouraging results.

Increased number of fractionated irradiation sessions does not improve the cellular response to methyl aminolevulinate-mediated photodynamic therapy.

Background: In the search to improve the efficacy of photodynamic therapy different approaches have been investigated until now. One of these approaches is the use of double fractionated irradiation schemes. This study aims to investigate the effect of increasing the numbers of fractionated irradiation sessions in methyl aminolevulinate-mediated photodynamic therapy on dysplastic oral keratinocytes by monitoring the changes in optical properties of cell culture.

Optical techniques for the noninvasive diagnosis of skin cancer.

Purpose: The aim of this paper is to provide an overview of the most investigated optical diagnostic techniques: optical coherence tomography, fluorescence spectrometry, reflectance spectrometry, Raman spectroscopy, and confocal microscopy.

Methods: A search of three databases was conducted using specific keywords and explicit inclusion and exclusion criteria for the analysis of the performances of these techniques in the pre- and postoperative diagnosis of skin cancers.

Results: Optical coherence tomography has shown promising results in the assessment of deep margins of skin tumors and inflammatory skin diseases, but differentiating premalignant from malignant lesions proved to be less effective.

Optical method for monitoring of photodynamic inactivation of bacteria.

Photodynamic inactivation is a new promising approach to treat bacterial infections. Usually, the evaluation of the efficacy of this method is done through time-consuming and labor-intensive microbiological test methods. This paper describes the development and implementation of an optical method to evaluate the photodynamic inactivation of bacteria based on non-invasive diffuse reflectance measurements.

In vivo comparison of simple and double-fractionated low-level laser irradiation schemes on the healing of rat skin lesions.

Objective: To compare the efficacy of a simple irradiation scheme with that of a double-fractionated irradiation scheme on the healing of rat skin lesions using in vivo monitoring of tissue diffuse reflectance.

Background Data: Low-level laser therapy (LLLT) is used in medicine for treating a wide range of pathological conditions. The practical benefits of laser treatment of acute and chronic conditions were obtained, using a single session of irradiation per day.

In vivo study of age-related changes in the optical properties of the skin.

The optical properties of the skin (absorption coefficient, scattering coefficient, refractive index) may serve to characterize the skin and are important for correct light dosimetry in many optical diagnostic procedures and laser treatments especially photodynamic therapy and laser therapy. We determined in vivo the optical properties of tissues near the wrist, elbow and knee in subjects of different ages using diffuse reflectance spectroscopy, having in view the establishment of laser system types for the laser treatment of posttraumatic lesions in subjects of different ages. Diffuse reflection of light from biological tissue is due to the variation in refractive index of tissular and cellular components and the surrounding medium and depends on the wavelength of the incident optical radiation.

Light sources for photodynamic inactivation of bacteria.

Bacteria have an important role in human and animal morbidity, and a great number of them have developed antibiotic resistance. In the past recent years a new way of dealing with this problem has been studied: photodynamic inactivation. This method is based on administration of a photosensitizing substance that fixes itself in the bacterial cell followed by exposure to a light source.

Photodynamic therapy of Walker tumors by multiple laser irradiation.

Objective: Photodynamic therapy of Walker tumor after subcutaneous administration of 5-ALA solution using a multiple laser irradiation scheme was monitored by the fluorescence imaging technique to investigate the effectiveness of 5-ALA-PDT.

Background Data: Photodynamic therapy (PDT) is a localized cancer treatment based on the selective uptake and retention of photosensitizer at the tumoral level and on the activation of the photosensitizer by a specific wavelength of light, aiming to induce cytotoxic reactions. As a new photosensitizer, the heme precursor 5- aminolevulinic acid has been introduced recently for photodynamic therapy of tumors and precancerous lesions of the skin.

The monitoring of the accumulation of protoporphyrin IX in Walker tumours by subcutaneous administration of delta-aminolevulinic acid.

Photodynamic therapy with protoporphyrin IX induced by delta-aminolevulinic acid (ALA) is mainly applied for the treatment of human superficial skin cancer. In this paper we present our study on photodynamic therapy (PDT) of the implanted Walker tumours using subcutaneous administration of ALA to improve the availability of ALA in the skin. We determined the accumulation and localization of protoporphyrin IX (PpIX) after subcutaneous administration of different concentrations of ALA in a physiological saline solutions, using fluorescence imaging technique.