Hyperspectral Image Processing for Detection and Grading of Skin Erythema

International audienceVisual assessment is the most common clinical investigation of skin reactions in radiotherapy. Due to the subjective nature of this method, additional noninvasive techniques are needed for more accurate evaluation. Our goal is to evaluate the effectiveness of hyperspectral image analysis for that purpose. In this pilot study, we focused on detection and grading of skin Erythema. This paper reports our proposed processing pipeline and experimental findings. Experiments have been performed to demonstrate the efficacy of the proposed approach for (1) reproducing clinical assessments, and (2) outperforming RGB imaging data

Correlation of Acute Radiation Dermatitis to Tissue Oxygenation in Radiation Therapy treated Breast Cancer Subjects

Over 95% of radiation therapy (RT) treated breast cancer subjects undergo an adverse skin reaction known as radiation dermatitis (RD). Assessment of severity or grading of RD is clinically visual and hence subjective. Our objective is to determine sub-clinical tissue oxygenation (StO2) changes in response to RT treatment in breast cancer subjects using near-infrared spectroscopic imaging and correlate these changes to RD grading. A WIRB approved 6-8 week longitudinal pilot study was carried out on 10 RT-treated subjects at Miami Cancer Institute. Significant changes (p \u3c 0.05) in StO2 of irradiated and contralateral chest wall and axilla regions with weeks of treatment were observed. The overall drop in StO2 was higher in irradiated regions compared to its contralateral region. This drop was negatively correlated to RD scaling. Pre-RT assessment of StO2 also related to severity in RD. The long-term goal is physiological based prediction of RD severity via tissue oxygenation measurements

Hyperspectral Imaging and Classification for Grading Skin Erythema

International audienceErythema is an inflammatory condition of the skin that is commonly used as a feature to monitor the progression of cutaneous diseases or treatment induced side effects. In radiation therapy, skin erythema is routinely assessed visually by an expert using standardized grading criteria. However, visual assessment (VA) is subjective and commonly used grading tools are too coarse to score the onset of erythema. Therefore, an objective method capable of quantitatively grading early erythema changes may help identify patients at higher risk for developing severe radiation induced skin toxicities. The purpose of this study is to investigate the feasibility of using hyperspectral imaging (HSI) for quantitative assessment of early erythema and to characterize its performance against VA documented on conventional digital photographic red-green-blue (RGB) images. Erythema was induced artificially on 3 volunteers in a controlled pilot study; and was subsequently measured using HSI and color imaging. HSI and color imaging data was analyzed using linear discriminant analysis (LDA) to perform classification. The classification results, including accuracy, and precision, demonstrated that HSI is superior to color imaging in skin erythema assessment

Diagnosis and treatment of premalignant changes of photodamaged skin : novel hyperspectral imaging and new therapeutical aspects

ABSTRACT Background and purpose: As the skin cancer burden continues to increase, there is an urgent need for novel methods for the early detection of skin cancers, and for new cost-effective treatments. The hyperspectral imaging system (HIS) is a novel technique which offers the dual advantages of allowing the imaging of large skin areas rapidly and non-invasively. Daylight photodynamic therapy (DL-PDT), with the advantages of excellent tolerability and convenience, is an attaractive therapy for actinic keratoses (AK) and field cancerization.This thesis aimed to enable early and effective treatment of common premalignancies of photo-damaged skin.The first purpose of this thesis was to evaluate the feasibility of HIS in the detection of field cancerized skin and in the detection of ill-defined borders of lentigo maligna (LM) and lentigo maligna melanoma (LMM). In addition, this thesis aimed to further develop the treatment of field cancerized skin with photodynamic therapy using a novel photosensitizer in combination with daylight (DL-PDT), and to evaluate the cost-effectiveness of DL-PDT. Methods: This thesis included four non-sponsored prospective clinical studies. The novel prototype HIS, used in studies I-II, was developed for the study at the VTT Technical Research Centre of Finland. The technique enabled in vivo imaging of the skin prior to surgical procedures and produced abundance maps of the affected skin areas. The results were verified by histopathology. Study III was randomized double-blinded intra-individual split-face trial comparing novel photosensitizer formulation, 5-aminolaevulinate nanoemulsion (BF-200 ALA) with methyl-5-aminolaevulinate (MAL) in DL-PDT of AKs. In addition to blinded clinical and histological treatment efficacy, tolerability of the treatment was assessed. Study IV evaluated the cost-effectiveness of MAL-DL-PDT compared to conventional MAL-LED-PDT. Results: In studies I-II HIS showed its feasibility in both the detection of subclinical borders of ill-defined lentigo malignas (LM) and lentigo maligna melanomas (LMM), and in the detection of early subclinical actinic keratoses (AK). In study I HIS accurately detected 20 of 23 (87%) of the LM/LMM borders as confirmed by histology. HIS was useful i.e. detected the lesion borders more accurately than a clinician using Wood s light in 11 of 23 (47.8%) cases. Six re-excisions could have been avoided with HIS. In 3/23 cases (13%) HIS was not in concordance with the histopathology, which in two cases HIS showed lesion extension which was not verified histologically (wrong positive) and in one case HIS missed the subclinical extension (wrong negative). In study II with 12 patients and 52 clinical AKs, HIS accurately detected all the clinical lesions in addition to numerous areas of subclinical damage. HIS findings matched the histopathological findings in all 33 biopsied areas (AK, n=28, photo-damaged skin, n=5), revealing 16 subclinical lesions of which 10 were not detected by fluorescence diagnosis. In study III (13 patients, 177 lesions) in a per patient (half-face) analysis BF-200 ALA cleared thin AKs more effectively than did MAL (p=0.027). In per lesion analysis the complete clearance rates were 84.5% for BF-200 ALA, and 74.2% for MAL (p=ns). The area response rates, including also the new appeared lesions (i.e.preventive effect), were 79.8% for BF-200 ALA and 65.6% for MAL, p=0.044. Histologically, DL-PDT effectively cleared all the signs of dysplasia in 61.5% lesions treated with BF-200 ALA and in 38.5% with MAL (p=ns). The mean decrease in p53 expression was 54.4% with BF-200 ALA, 34 % with MAL (p=ns). DL-treatment was nearly painless with both photosensitizers. BF-200 ALA and MAL DL-treatments were similarly tolerated as regards to adverse reactions. In study IV 70 patients (210 target lesions) randomized to receive DL-PDT or LED-PDT with MAL, at six months the patient complete response rates were 15 of 35 (42.9%) and 24 of 35 (68.6%), (p=0.030) and lesion clearance rates were 72.4% and 89.2%, respectively (p=0.0025). DL-PDT required significantly less time at the clinic (p less than 0.0001) and could be used with lower total costs ( 132) compared to conventional LED-PDT ( 170), p=0.022. However, in terms of cost-effectiveness MAL-DL-PDT was found to give less value for money compared to MAL-LED-PDT. The incrementl cost-effectiveness ratio (ICER) showed the monetary gain of 147 per unit of effectiveness lost. Thus, the use of DL-PDT instead of LED-PDT would decrease the healing probability but only low incremental cost savings would be achieved. The costs per complete responder were 308 for MAL DL-PDT and 248 for MAL LED-PDT, p= 0.004. Conclusions: The more accurate pre-surgical assessment of the subclinical borders of LM and LMM with HIS could lead to fewer re-excixions, which furthermore could reduce the burden to both patients and clinics. In addition, the early non-invasive detection of skin field cancerization could enhance the treatment process by revealing the as yet subclinical areas in need of treatment, and could possibly aid the monitoring of treatment efficacy. Even though HIS was found to be useful in these two indications, more studies are warranted to qualify the optimal mathematical algorithms for diagnostic use.The use of novel a photosensitizer formulation, BF-200 ALA, in DL-PDT could lead in lower costs and increase the efficacy. Interestingly, the efficacy of DL-PDT with BF-200 ALA was approaching the efficacy achieved with conventional LED-PDT. As field cancerized skin should be treated as a chronic disease requiring repeated treatments, DL-PDT offers a painless and convenient option for this purpose. However, DL-PDT with MAL provided less value for money compared to conventional MAL-PDT. The cost-effectiveness of BF-200 ALA in DL-PDT for AKs needs further studies.TIIVISTELMÄ Ihosyöpien määrä on jatkuvassa räjähdysmäisessä kasvussa maailmanlaajuisesti. Tämä kuormittaa terveydenhuoltoa merkittävästi. Taudinmäärityksen kehittäminen, siten että ihosyövät pystytään tunnistamaan jo varhaisessa vaiheessa sekä hoitoalueiden aiempaa tarkempi määrittäminen lisähoitojen välttämiseksi, ovat keskeisiä keinoja rajoittaa hoitokustannuksia. Lisäksi on tarve uusille, helposti toteutettaville ja kustannusvaikuttaville hoitomuodoille. Väitöstyössä tutkittiin uutta Suomessa kehitettyä hyperspektritekniikkaa ihon okasolusyövän varhaisasteiden, ns. subkliinisten aktiinikeratoosien, tunnistamisessa, sekä huonosti rajautuvien ihon pintamelanoomien, ns. lentigo malignojen, rajojen määrittämisessä lisäleikkausten välttämiseksi. Väitöstyössä selvitettiin myös uuden päivänvalolla toteutettavan fotodynaamisen hoidon (päivänvalo-PDT) tehoa ja turvallisuutta, sekä kustannusvaikuttavuutta ihon okasolusyövän esiasteiden eli aktiinikeratoosien hoidossa. Tutkimuksessa tutkittiin kahta iholle levitettävää valoherkistäjävoidetta, joista toista ei aiemmin ole käytetty tällä indikaatiolla. Tutkimuksella haluttiin kehittää ihosyöpien varhaisvaiheiden hoitoprosessia resursseja ja kustannuksia säästäväksi, sekä löytää uusia, hyvin siedettyjä mutta tehokkaita hoitomuotoja. Väitöskirjatyöhön sisältyi neljä prospektiivista kliinistä tutkimusta. Hyperspektrikuvantaminen todettiin hyödylliseksi varhaisten, silmälle vielä näkymättömien, aktiinikeratoosien havaitsemisessa. Lisäksi hyperspektrikuvantamisen avulla kyettiin havaitsemaan silmälle näkymättömiä lentigo maligna-kasvainten rajoja. Tämä auttaa entistä tarkemmin määrittämään hoitoalueet ja saattaa mahdollistaa entistä tarkemman hoidon seurannan. Turhilta lisäleikkauksilta saatetaan välttyä. Päivänvalo-PDT osoittautui tehokkaaksi, turvalliseksi ja paremmin siedetyksi kuin perinteinen fotodynaaminen hoito (keinovalo-PDT), missä valolähteenä on keinovalo. Päivänvalo-PDT vei vähemmän sekä poliklinikan henkilökunnan että potilaan aikaa. Keinovalo-PDT osoittautui kuitenkin kustannustehokkaammaksi kuin päivänvalohoito, kun lääkkeenä oli perinteinen valoherkistäjä, metyyliaminolevulinaatti (MAL). Uusi valoherkistäjälääkkeet, aminolevulinaatti nanoemulsio (BF-200 ALA), osoittautui tehokkaaksi ja turvallisia aktiinikeratoosien päivänvalo-PDT:ssa. Hyperspektrikuvantaminen on lupaava uusi tekniikka silmälle näkymättömien ihosyöpien varhaisvaiheiden havaitsemissa sekä hoitoa tarvitsevan ihosyöpäalueen määrittämisessä. Päivänvalo-PDT mahdollistaa laajojen valovaurioalueiden hoidon tehokkaasti ja kivuttomasti. Uusien tehokkaiden valoherkistäjien käyttö saattaa parantaa hoitotehoa, laskea hoitokustannuksia ja siten lisätä hoidon kustannustehokkuutta

Medical vision: web and mobile medical image retrieval system based on google cloud vision

The application of information technology is rapidly utilized in the medical system. There is also a massive development in the automatic method for recognizing and detecting objects in the real world. In this study, we present a system called Medical Vision which is designed for people who has no expertise in medical. Medical Vision is a web and mobile-based application to give an initial knowledge in a medical image. This system has 5 features; object detection, web detection, object labeling, safe search, and image properties. These features are run by embedding Google Vision API in the system. We evaluate this system by observing the result of some medical images which inputted into the system. The results showed that our system presents a promising performance and able to give relevant information related to the given image

The role and safety of UVA and UVB in UV-induced skin erythema

BackgroundDifferent wavelengths of ultraviolet (UV) light cause skin damage through different mechanisms. Minimal erythema dose (MED) is usually used to clinically evaluate skin sensitivity to ultraviolet radiation by inducing skin erythema using ultraviolet B (UVB) or ultraviolet A (UVA) + UVB.AimsIn this study, we detected changes in the blood flow at the MED erythema caused by UVB and UVA + UVB radiation through optical coherence tomography (OCT) to explain the role of different bands of ultraviolet rays in erythema induction.MethodsTwo MED irradiation areas on the subjects' back were irradiated with UVB alone or UVA + UVB (UVA: UVB = 8:1). The absolute energy of UVB remained the same in UVB and UVA+UVB. At 24 h after the irradiation, the changes in the blood flow in the MED area were detected using OCT.ResultsCompared with the blank control, the maximum blood flow depth, blood flow peak, and total blood flow of UVB-MED and UVA+UVB-MED were significantly increased. Notably, the maximum blood flow depth and blood flow peak of UVB-MED were higher than UVA+UVB-MED. There was no significant difference in total blood perfusion between UVA+UVB-MED and UVB-MED. Under the same UVB energy, the skin erythema caused by UVA + UVB was weaker than UVB alone.ConclusionsThe analysis of local blood flow by OCT showed that the peak and maximum depth of local blood flow caused by UVB alone were significantly higher than UVA + UVB

Using Domain-Specific Information in Image Processing

With the increasing availability of high resolution imaging tools, even in our pockets (i.e. smartphones), everyday users can do far more than simply digitally capturing a family moment. The ease of new applications available in these portable forms, linked with users who have expert knowledge about the images and tasks, opens the door to new possibilities. With this in mind we propose two new approaches that utilize the user's knowledge for improved results. We apply these approaches to real life problems in medical and scientific image applications. In the first approach, we introduce a class of linear and nonlinear methods which we call Domain-Specific Grayscale (DSGS) methods. A DSGS method transforms a color image into an image analogous to a grayscale image, where user-specified information is used to optimize a specified image processing task and reduce the computational complexity. We introduce new methods based on projection into the space of single-coordinate images, and we adapt support vector machines by using their scores to create a DSGS image. We apply these methods to applications in dermatology, analyzing images of skin tests and skin lesions, and demonstrate their usefulness. In the second approach, we introduce a tool for improved image deblurring that safeguards against bias that can easily be introduced by a user favoring a particular result. This is particularly important in scientific and medical applications used for discovery or diagnosis. We provide real-time results of choices of regularization methods and parameter selection, and we check the statistical plausibility of the results, using three statistical diagnostics, allowing a user to see the results of the choices. Our work demonstrates the utility of domain-specific information, supplied by the user, in improving the results of image processing algorithms

System of System Integration for Hyperspectral Imaging Microscopy

Hyperspectral imaging (HSI) has become a leading tool in the medical field due to its capabilities for providing assessments of tissue pathology and separation of fluorescence signals. Acquisition speeds have been slow due to the need to acquire signal in many spectral bands and the light losses associated with technologies of spectral filtering. Traditional methods resulted in limited signal strength which placed limitations on time sensitive and photosensitive assays. For example, the distribution of cyclic adenosine monophosphate (cAMP) is largely undetermined because current microscope technologies lack the combination of speed, resolution, and spectral ability to accurately measure Forster resonance energy transfer (FRET). The work presented in this dissertation assesses the feasibility of integrating excitation-scanning hyperspectral imaging methods in widefield and confocal microscopy as a potential solution to improving acquisition speeds without compromising sensitivity and specificity. Our laboratory has previously proposed excitation-scanning approaches to improve signal-to-noise ratio (SNR) and showed that by using excitation-scanning, most-to-all emitted light at each excitation wavelength band can be detected which in turn, increases the SNR. This dissertation describes development and early feasibility studies for two novel prototype concepts as an alternative excitation-scanning HSI technology that may xvi increase acquisition speeds without compromising sensitivity or specificity. To achieve this, two new technologies for excitation-scanning HSI were conceptually designed: - LED-based spectral illumination for widefield microscopy - Supercontinuum-laser-based spectral illumination for spinning disk confocal microscopy. Next, design concepts were theoretically evaluated and optimized, leading to prototype testing. To evaluate the performance of each concept, prototype systems were integrated with other systems and subsystems, calibrated and feasibility assays were executed. This dissertation is divided into three main sections: 1) early development feasibility results of an excitation-scanning widefield system of systems prototype utilizing LED-based HSI, 2) Excitation-scanning HSI and image analysis methods used for endmember identification in fluorescence microscopy studies, and 3) early development feasibility of an excitation-scanning confocal SoS prototype utilizing a supercontinuum laser light source. Integration and testing results proved initial feasibility of both LED-based and broadband-based SoSs. The LED-based light source was successfully tested on a widefield microscope, while the broadband light source system was successfully tested on a confocal microscope. Feasibility for the LED-based system showed that further optical transmission optimization is needed to achieve high acquisition rates without compromising sensitivity or specificity. Early feasibility study results for the broadband-based system showed a successful proof of concept. Findings presented in this dissertation are expected to impact the fields of cellular physiology, medical sciences, and clinical diagnostics by providing the ability for high speed, high sensitivity microscopic imaging with spectroscopic discrimination

Hypergranulatory tissue in breast implant surgery and skin scar formation

In this thesis hypergranulation tissue in both the breast after breast implant surgery, as well as in the skin (scar formation) is explored. The histological composition of capsular contracture after breast implant surgery and the role of silicone in this tissue is investigated in multiple papers. Furthermore, the classification used to grade capsular contracture complaints is evaluated. In the second part, the role the systemic immune system has in hypertrophic scarring is examined, and how to use these differences to enable prognostic tools