Hemoglobin Concentration as an Indicator of Skin Radiation Damage During Radiation Therapy Treatments.

PURPOSE: Acute radiation dermatitis (ARD) is the most common side effect reported by patients undergoing radiation therapy (RT). Currently, the assessment of the severity of the reaction is based on the visual assessment of the skin, which is a subjective method, depending on many factors. The main aim of this study was to investigate the usefulness of hyperspectral imaging (HSI) in the assessment of ARD and find physiological factors that could be correlated with ARD. METHODS AND MATERIALS: In this clinical pilot trial, weekly acquisitions of hyperspectral camera images of irradiated skin were performed for 5 weeks of RT and at the posttreatment follow-up visit which took place 30 to 40 days after the last fraction of RT. At the same time, the severity of radiodermatitis was assessed based on the criteria of the National Cancer Institute Common Terminology Criteria for Adverse Events (CTCAE). The content and concentration of chromophores in irradiated skin were quantitatively determined using a hyperspectral camera. RESULTS: The use of HSI supported by image analysis and processing methods allowed for the determination of the content and distribution of hemoglobin and melanin in the irradiated skin. It was found that the hemoglobin concentration is correlated with the subjective assessment made according to the CTCAE protocol. CONCLUSIONS: HSI is a sensitive and specific method of analyzing the concentration of chromophores in the skin, including hemoglobin. A clear correlation was found between hemoglobin concentration and CTCAE v.5 scale because of which HSI can be considered as an objective method of skin assessment during RT.

In vitro hyperspectral analysis of tattoo dyes.

BACKGROUND: There is no method that can guarantee effective, quick, and noninvasive removal of tattoo dyes. Laser methods are considered to be the method of choice. In this study, an attempt was made to determine the in vitro spectral characteristics of selected dyes used in permanent makeup and tattoos and to analyze the obtained parameters in terms of laser treatments optimization. MATERIALS AND METHODS: Hyperspectral analysis was performed to determine the spectral characteristics of the dye on the entire surface of the slide. Seven dyes used in permanent makeup and tattoos were analyzed in vitro. The maximum reflectance and the wavelength for a given dye were determined for the maximum reflectance in the studied wavelength range: 400-1000 nm. The optical properties of the dyes were determined based on visible light imaging using camera. RESULTS: The maximum radiation reflectance ranges from 634 to 732 nm for the tested dyes. Visually very similar colors may differ significantly in the wavelength for which the maximum absorption of the radiation occurs. White and yellow dyes are characterized by the highest reflectance value. The black dye is characterized by the lowest reflectance coefficient. Low reflectance of black dye results in more safe and effective removal treatments. CONCLUSION: The homogeneity of radiation absorption can be identified using methods of analysis and processing of images in visible light. Optimization of the wavelength of which the maximum absorption/reflectance of radiation occurs may allow us to increase the effectiveness of laser treatments for removing permanent makeup and tattoos.

Application of a three-dimensional scanner to the quantitative assessment of the nail plate condition after a hybrid manicure procedure-Preliminary study.

BACKGROUND: About 90% of women worldwide use nail care products, including manicure ones. A manicure procedure results in nail damage, therefore it is necessary to search for new, objective methods of assessing the impact of the procedures and products applied within the nail plate. In this study, an attempt was made to quantify the impact of manicure procedures on the nail plate condition. MATERIALS AND METHODS: Twenty thumb nail plates were examined. Before the manicure procedures, alginate casts were prepared for each of the subjects. The analysis of the three-dimensional (3D) nail surface structure included the assessment of the nail sections and the assessment of differences in the nail structure after superposition of 3D images of the nail plates before and after the manicure procedures. RESULTS: The obtained results show that the nail plate structure changed to a similar extent in each measured section after the manicure procedure. A change in the height of the nails is not a desirable phenomenon as it suggests damage to the nail caused by the substances included in the preparations applied to the nails, acetone, or filing the nail plate. This proves the great influence of the technique of removing artificial nails on the structure of the natural plate. CONCLUSION: The use of a 3D scanner allows for precise, biometric, quantitative, and repeatable measurements of changes in the nail structure after a manicure procedure. The use of the hybrid and gel manicure procedure causes significant damage to the nail plate, especially in its distal portion.

Classification Tree to Analyze Factors Connected with Post Operative Complications of Cataract Surgery in a Teaching Hospital.

BACKGROUND: Artificial intelligence (AI) is becoming ever more frequently applied in medicine and, consequently, also in ophthalmology to improve both the quality of work for physicians and the quality of care for patients. The aim of this study is to use AI, in particular classification tree, for the evaluation of both ocular and systemic features involved in the onset of complications due to cataract surgery in a teaching hospital. METHODS: The charts of 1392 eyes of 1392 patients, with a mean age of 71.3 ± 8.2 years old, were reviewed to collect the ocular and systemic data before, during and after cataract surgery, including post-operative complications. All these data were processed by a classification tree algorithm, producing more than 260 million simulations, aiming to develop a predictive model. RESULTS: Postoperative complications were observed in 168 patients. According to the AI analysis, the pre-operative characteristics involved in the insurgence of complications were: ocular comorbidities, lower visual acuity, higher astigmatism and intra-operative complications. CONCLUSIONS: Artificial intelligence application may be an interesting tool in the physician's hands to develop customized algorithms that can, in advance, define the post-operative complication risk. This may help in improving both the quality and the outcomes of the surgery as well as in preventing patient dissatisfaction.

The use of infrared thermal imaging in tonometry with a Scheimpflug camera.

Infrared thermal imaging is currently used in almost every field of medicine. This paper presents the novel use of thermography in ophthalmology - using a thermal camera to assess correct intraocular pressure measurement depending on the position of the patient's head during non-contact tonometry. For the analysed group of 10 healthy subjects, thermographic images of the face were recorded before and after intraocular pressure testing. Pressure was tested with a non-contact tonometer with a Scheimpflug camera. For the acquired 20: 2D images (thermograms), an analysis of the characteristic areas of the face determined temperature changes of the patient's face in contact with the tonometer frame. Analysis and processing of the acquired thermograms was carried out in MATLAB® with the Image Processing Toolbox. The results clearly showed a decrease in the patient's face temperature where the face was in contact with tonometer supports. Temperature changes in the patient's face provide valuable information about the correct position of their head in the device, which directly translates into measurement quality. Therefore, the analysis of changes in the patient's face temperature both before and after the examination can be a tool for assessing correct patient positioning in the tonometer supports.

Application of Artificial Intelligence in the Analysis of Features Affecting Cataract Surgery Complications in a Teaching Hospital.

Aims: To evaluate the ocular and systemic factors involved in cataract surgery complications in a teaching hospital using artificial intelligence. Methods: One eye of 1,229 patients with a mean age of 70.2 ± 10.3 years old that underwent cataract surgery was selected for this study. Ocular and systemic details of the patients were recorded and then analyzed by means of artificial intelligence. A total of 1.25 billion simulations of artificial intelligence learning and testing were conducted on several variables and a customized model of analysis was developed. Results: A total of 73 complications were recorded in this study. According to the analysis performed, the main factors involved in cataract surgery complications were: a surgeon in training, axial length and intraocular lens power. The model predicted how long surgery would last with an error of <6 min compared to the effective time needed. Conclusions: According to the data here obtained, artificial intelligence could be an interesting option to build customized models able to prevent complications and to predict actual surgery time. The customized algorithm option allows the development of better models adaptable to different units as well as the possibility to be calibrated for the same unit along time.

Diagnosis of Temporomandibular Disorders Using Thermovision Imaging.

Temporomandibular joint dysfunction (TMD) is a chronic disease of various etiologies. Correct TMD diagnosis enables to apply effective treatment and significantly improves the quality of patients' lives. One of the diagnostic methods subjected to evaluation in recent years is thermography, which enables safe, noninvasive, and quick imaging of the temperature distribution of temporomandibular joint-associated tissues. This paper, based on Medline, Dentistry & Oral Sciences Source, Academic Search Ultimate, Medline Complete databases, presents basic information related to thermovision imaging and outlines the direction of research conducted in recent years which fight with difficulties in the interpretation of thermograms that require specialized, dedicated analysis and processing of the obtained images. The problem concerns also no standardized protocol for measuring masticatory muscle temperature.

Corrigendum to "Enamel Thickness before and after Orthodontic Treatment Analysed in Optical Coherence Tomography".

[This corrects the article DOI: 10.1155/2017/8390575.].

A new method for detecting the outer corneal contour in images from an ultra-fast Scheimpflug camera.

BACKGROUND: The Corvis® ST tonometer is an innovative device which, by combining a classic non-contact tonometer with an ultra-fast Scheimpflug camera, provides a number of parameters allowing for the assessment of corneal biomechanics. The acquired biomechanical parameters improve medical diagnosis of selected eye diseases. One of the key elements in biomechanical measurements is the correct corneal contour detection, which is the basis for further calculations. The presented study deals with the problem of outer corneal edge detection based on a series of images from the afore-mentioned device. Corneal contour detection is the first and extremely important stage in the acquisition and analysis of corneal dynamic parameters. RESULT: A total of 15,400 images from the Corvis® ST tonometer acquired from 110 patients undergoing routine ophthalmologic examinations were analysed. A method of outer corneal edge detection on the basis of a series of images from the Corvis® ST was proposed. The method was compared with known and commonly used edge detectors: Sobel, Roberts, and Canny operators, as well as others, known from the literature. The analysis was carried out in MATLAB® version 9.0.0.341360 (R2016a) with the Image Processing Toolbox (version 9.4) and the Neural Network Toolbox (version 9.0). The method presented in this paper provided the smallest values of the mean error (0.16%), stability (standard deviation 0.19%) and resistance to noise, characteristic for Corvis® ST tonometry tests, compared to the methods known from the literature. The errors were 5.78 ± 9.19%, 3.43 ± 6.21%, and 1.26 ± 3.11% for the Roberts, Sobel, and Canny methods, respectively. CONCLUSIONS: The proposed new method for detecting the outer corneal contour increases the accuracy of intraocular pressure measurements. It can be used to analyse dynamic parameters of the cornea.

Corneal deformation amplitude analysis for keratoconus detection through compensation for intraocular pressure and integration with horizontal thickness profile.

BACKGROUND: The Corvis ST provides measurements of intraocular pressure (IOP) and a biomechanically-corrected IOP (bIOP). IOP influences corneal deflection amplitude (DA), which may affect the diagnosis of keratoconus. Compensating for IOP in DA values may improve the detection of keratoconus. METHODS: 195 healthy eyes and 136 eyes with keratoconus were included for developing different approaches to distinguish normal and keratoconic corneas using attribute selection and discriminant function. The IOP compensation is proposed by dividing the DA by the IOP values. The first approaches include DA compensated for either IOP or bIOP and other parameters from the deformation corneal response (DCR). Another approach integrated the horizontal corneal thickness profile (HCTP). The best classifiers developed were applied in a validation database of 156 healthy eyes and 87 eyes with keratoconus. Results were compared with the current Corvis Biomechanical Index (CBI). RESULTS: The best biomechanical approach used the DA values compensated by IOP (Approach 2) using a linear discriminant function and reached AUC 0.954, with a sensitivity of 88.2% and a specificity of 97.4%. When thickness horizontal profile data was integrated (Approach 4), the best function was the diagquadratic, resulting in an AUC of 0.960, with a sensitivity of 89.7% and a specificity of 96.4%. There was no significant difference in the results between approaches 2 and 4 with the CBI in the training and validation databases. CONCLUSIONS: By compensating for the IOP, and with the horizontal thickness profile included or excluded, it was possible to generate a classifier based only on biomechanical information with a similar result to the CBI.

Evaluation of changes in enamel thickness after orthodontic treatment depending on the force applied to remove orthodontic brackets: OCT analysis and universal testing machine.

BACKGROUND: Adhesive materials used in orthodontics have contributed to the broadening of treatment options with fixed braces. The adhesive materials physically and chemically bond to the enamel surface and orthodontic bracket base, which, apart from offering advantages, also entails the risk of enamel damage when removing these materials from the tissue surface after the treatment is complete. OBJECTIVES: The objective of this study was to assess how the bond strength of adhesive materials affects enamel thickness after removing brackets and whether the type of bonding system affects the amount of adhesive strength of the discussed materials. MATERIAL AND METHODS: The tests were carried out on 2 groups of 40 bovine teeth in each group. In the 1st group, the classical orthophosphoric acid and the Transbond Plus self-etching primer (SEP) were used. In the 2nd group, the Transbond XT SEP was applied. In both groups, Transbond XT Light Cure Adhesive was used. The same metal orthodontic brackets were attached to the enamel surface. Optical Coherence Tomography (OCT) scans were made before and after removing brackets, which enabled tissue thickness measurements. The bond strength was evaluated using a universal testing machine. Parametric tests were performed on all obtained variables. Student's t-tests for independent samples and analysis of correlation with Pearson's r were carried out. RESULTS: The bond strength between the orthodontic bracket and enamel is statistically significantly different in the 1st group and the 2nd group, and is higher in the 2nd group. CONCLUSIONS: There are no significant differences in enamel thickness depending on the bonding system type and there is no correlation between the enamel thickness and the bond strength of orthodontic brackets to the enamel.

Novel dynamic corneal response parameters in a practice use: a critical review.

BACKGROUND: Non-contact tonometers based on the method using air puff and Scheimpflug's fast camera are one of the latest devices allowing the measurement of intraocular pressure and additional biomechanical parameters of the cornea. Biomechanical features significantly affect changes in intraocular pressure values, as well as their changes, may indicate the possibility of corneal ectasia. This work presents the latest and already known biomechanical parameters available in the new offered software. The authors focused on their practical application and the diagnostic credibility indicated in the literature. DISCUSSION: An overview of available literature indicates the importance of new dynamic corneal parameters. The latest parameters developed on the basis of biomechanics analysis of corneal deformation process, available in non-contact tonometers using Scheimpflug's fast camera, are used in the evaluation of laser refractive surgery procedures, e.g. LASIK procedure. In addition, the assessment of changes in biomechanically corrected intraocular pressure confirms its independence from changes in the corneal biomechanics which may allow an intraocular pressure real assessment. The newly developed Corvis Biomechanical Index combined with the corneal tomography and topography assessment is an important aid in the classification of patients with keratoconus. CONCLUSION: New parameters characterising corneal deformation, including Corvis Biomechanical Index and biomechanical compensated intraocular pressure, significantly extend the diagnostic capabilities of this device and may be helpful in assessing corneal diseases of the eye. Nevertheless, further research is needed to confirm their diagnostic pertinence.

The use of microtomographic imaging in the identification of counterfeit medicines.

The practice of drug counterfeiting is an important challenge due to the extremely rapid growth rate of this disturbing trend and its immense potential harmfulness. According to WHO even 10% of counterfeit medicines can be exact copies of genuine medicines: they have exactly the same quantitative and qualitative composition in terms of both API and excipients. Thus, the identification of such drugs using chemical analysis methods can be very difficult or even impossible. The aim of this study was to verify the effectiveness of using computed microtomography in the identification of counterfeit medicines. The General Electric v|tome|x s microtomography system was used in the study. The recorded microtomographic scans were subjected to analysis and image processing. The following parameters of image analysis and processing were identified: mean brightness, homogeneity, contrast, quadratic tree decomposition. The original and falsified 100-mg Viagra® tablets (Pfizer) were compared. 8 original Viagra® tablets (hereinafter referred to as T) and 8 falsified tablets (hereinafter referred to as F1-F8) were tested. The range of variation for the genuine medicines against fake products was: brightness: 90.9-117.1 vs 33.8, 50.1, homogeneity: 0.84-0.92 vs 0.94-1.01 and quadratic tree decomposition for the 1 × 1 mask: 55768-58792 vs 0-439. The proposed method of microtomographic image analysis and processing enables to identify solid dosage forms, including those that are an accurate chemical copy, with high sensitivity and specificity, 94.5% and 97%, respectively. The advantage of the µCT method is its high efficiency and speed, whereas the disadvantages include the possibility of using only solid dosage forms and high equipment costs.

In vivo dynamic thermal imaging of skin radiofrequency treatment.

In recent years, popularity of radiofrequency (RF) has increased significantly. They are characterized by a low risk of complications and relatively high effectiveness. RF use high-frequency currents causing oscillating motion of ions resulting in temperature rise stimulating skin regeneration processes. The aim of this work was the thermographic evaluation of the skin exposed to RF of different intensity. The dynamic thermal imaging was used to study the temperature of the skin exposed to RF. The research was carried out in two locations with different adipose tissue content: abdomen (ROI1) and forearm (ROI2). In the ROI1 area, RF was applied at nominal power range from 250 to 1750 W, while in ROI2 area: from 250 to 1000 W. The obtained thermographic data were fitted to exponential functions. A clear dependence of obtained thermokinetic parameters with the anatomical location of exposure to RF was demonstrated. Thicker layer of adipose tissue directly under the skin resulted in obtaining higher maximum temperatures of the skin surface during the procedure (maximum obtained temperature equaled 40.8°C). The temperature of the skin under the head of the device does not translate to subjective patient experiences. In anatomic locations filled with less adipose tissue mass, tolerance to RF is much lower. The dynamics of skin temperature changes, after the RF treatment, can be described by means of a single exponential function where the key parameter is the time constant t1 defining the dynamics of skin temperature changes. The depth of the RF influence is slightly correlated with the RF power.

Optical coherence tomography as a non-invasive method of enamel thickness diagnosis after orthodontic treatment by 3 different types of brackets.

BACKGROUND: Medical digital imaging is the basis of effective medical diagnosis and is now in the mainstream of a dynamically developing branch of science. Optical coherence tomography (OCT) enables real-time in situ imaging of tissues without the need for biopsy, histological procedures or X-rays. OBJECTIVES: The aim of the study was to evaluate the application of OCT in orthodontic diagnostics and clinical practice by assessing the thickness of the enamel before and after orthodontic treatment. MATERIAL AND METHODS: A hundred and eighty teeth in this in vitro study were divided into 3 groups of 60 teeth each. In each group (Group 1 - metal brackets, Group 2 - ceramic brackets and Group 3 - composite brackets), the orthodontic brackets were attached to the enamel using the 5th-generation adhesive system. The image of the enamel tissue was captured with a 3D-OCT camera before installing orthodontic brackets and after debonding and mechanical processing. The obtained OCT scans were subjected to expert IT analysis. For the statistical analysis, the Shapiro-Wilk test, the median test, the Mann-Whitney U test, Friedman 2-way analysis of variance (ANOVA), Wilcoxon matched pairs signed ranks test, the χ2 test of independence with Yates's correction, and Fisher's exact test were used. Maxwell's general principle was followed when using this type of test. The level of significance was set at p = 0.05. RESULTS: The thickness of the enamel varied least when metal brackets were used. The changes in enamel thickness in the composite and ceramic bracket groups were not statistically significant. CONCLUSIONS: Optical coherence tomography is an effective diagnostic tool to evaluate the thickness of the enamel tissue before and after orthodontic treatment. Changes in the enamel layer thickness after orthodontic treatment are determined by the type of material which the orthodontic bracket is made of.

Improving accuracy of corneal power measurement with partial coherence interferometry after corneal refractive surgery using a multivariate polynomial approach.

BACKGROUND: To improve accuracy of IOLMaster (Carl Zeiss, Jena, Germany) in corneal power measurement after myopic excimer corneal refractive surgery (MECRS) using multivariate polynomial analysis (MPA). METHODS: One eye of each of 403 patients (mean age 31.53 ± 8.47 years) was subjected to MECRS for a myopic defect, measured as spherical equivalent, ranging from - 9.50 to - 1 D (mean - 4.55 ± 2.20 D). Each patient underwent a complete eye examination and IOLMaster scan before surgery and at 1, 3 and 6 months follow up. Axial length (AL), flatter keratometry value (K1), steeper keratometry value (K2), mean keratometry value (KM) and anterior chamber depth measured from the corneal endothelium to the anterior surface of the lens (ACD) were used in a MPA to devise a method to improve accuracy of KM measurements. RESULTS: Using AL, K1, K2 and ACD measured after surgery in polynomial degree 2 analysis, mean error of corneal power evaluation after MECRS was + 0.16 ± 0.19 D. CONCLUSIONS: MPA was found to be an effective tool in devising a method to improve precision in corneal power evaluation in eyes previously subjected to MECRS, according to our results.

Corneal Vibrations during Intraocular Pressure Measurement with an Air-Puff Method.

Introduction: The paper presents a commentary on the method of analysis of corneal vibrations occurring during eye pressure measurements with air-puff tonometers, for example, Corvis. The presented definition and measurement method allow for the analysis of image sequences of eye responses-cornea deformation. In particular, the outer corneal contour and sclera fragments are analysed, and 3D reconstruction is performed. Methods: On this basis, well-known parameters such as eyeball reaction or corneal response are determined. The next steps of analysis allow for automatic and reproducible separation of four different corneal vibrations. These vibrations are associated with (1) the location of the maximum of cornea deformation; (2) the cutoff area measured in relation to the cornea in a steady state; (3) the maximum of peaks occurring between applanations; and (4) the other characteristic points of the corneal contour. Results: The results obtained enable (1) automatic determination of the amplitude of vibrations; (2) determination of the frequency of vibrations; and (3) determination of the correlation between the selected types of vibrations. Conclusions: These are diagnostic features that can be directly applied clinically for new and archived data.

Machine learning and medicine: book review and commentary.

This article is a review of the book "Master machine learning algorithms, discover how they work and implement them from scratch" (ISBN: not available, 37 USD, 163 pages) edited by Jason Brownlee published by the Author, edition, v1.10 http://MachineLearningMastery.com . An accompanying commentary discusses some of the issues that are involved with use of machine learning and data mining techniques to develop predictive models for diagnosis or prognosis of disease, and to call attention to additional requirements for developing diagnostic and prognostic algorithms that are generally useful in medicine. Appendix provides examples that illustrate potential problems with machine learning that are not addressed in the reviewed book.