Risks and benefits of dermatological machine learning health care applications-an overview and ethical analysis.

BACKGROUND: Visual data are particularly amenable for machine learning techniques. With clinical photography established for skin surveillance and documentation purposes as well as progress checks, dermatology is an ideal field for the development and application of emerging machine learning health care applications (ML-HCAs). To date, several ML-HCAs have detected malignant skin lesions on par with experts or found overlooked visual patterns that correlate with certain dermatological diseases. However, it is well established that ML-HCAs come with ethical and social implications. OBJECTIVES: Currently, there is a lack of research that establishes model design, training, usage and regulation of such technologies sufficient to ensure ethically and socially responsible development and clinical translation, specifically within the field of dermatology. With this paper, we aim to give an overview of currently discussed ethical issues relating to dermatological ML-HCAs. METHODS: On the basis of a thematic, keyword-based literature search, we performed an ethical analysis against established frameworks of biomedical ethics. We combined our results with current, relevant normative machine learning ethics literature to identify the status quo of the ethics of ML-HCAs in dermatology. We describe the benefits and risks of dermatological ML-HCAs that are currently being developed for clinical purposes. RESULTS: The potential benefits range from better patient outcomes to better knowledge accessibility to decreasing health care disparities, that is, standards of care between different population groups. The risks associated with ML-HCAs range from confidentiality issues to individual patient outcomes as well as the exacerbation of prevalent health care disparities. We discuss the practical implications for all stages of dermatological ML-HCA development. CONCLUSION: We found that ML-HCAs present stakeholder-specific risks for patients, health care professionals and society, which need to be considered separately. The discipline lacks sufficient biomedical ethics research that could standardize the approach to ML-HCA model design, training, use and regulation of such technologies.

Deep learning-based classification of dermatological lesions given a limited amount of labelled data.

BACKGROUND: Artificial intelligence (AI) techniques are promising in early diagnosis of skin diseases. However, a precondition for their success is the access to large-scaled annotated data. Until now, obtaining this data has only been feasible with very high personnel and financial resources. OBJECTIVES: The aim of this study was to overcome the obstacle caused by the scarcity of labelled data. METHODS: To simulate the scenario of label shortage, we discarded a proportion of labels of the training set. The training set consisted of both labelled and unlabelled images. We then leveraged a self-supervised learning technique to pretrain the AI model on the unlabelled images. Next, we fine-tuned the pretrained model on the labelled images. RESULTS: When the images in the training dataset were fully labelled, the self-supervised pretrained model achieved 95.7% of accuracy, 91.7% of precision and 90.7% of sensitivity. When only 10% of the data were labelled, the model could still yield 87.7% of accuracy, 81.7% of precision and 68.6% of sensitivity. In addition, we also empirically verified that the AI model and dermatologists are consistent in visually inspecting the skin images. CONCLUSIONS: The experimental results demonstrate the great potential of the self-supervised learning in alleviating the scarcity of annotated data.

Ex vivo confocal laser scanning microscopy for bullous pemphigoid diagnostics: new era in direct immunofluorescence?

BACKGROUND: Ex vivo confocal laser scanning microscopy (ex vivo CLSM) is a novel diagnostic method allowing rapid, high-resolution imaging of excised skin samples. Furthermore, fluorescent detection is possible using fluorescent-labelled antibodies. OBJECTIVE: To assess the applicability of ex vivo CLSM in the detection of basement membrane (BM) fluorescence in bullous pemphigoid (BP) and to compare its diagnostic accuracy with direct immunofluorescence (DIF) microscopy. METHODS: A total of 81 sections of 49 BP patients with positive DIF microscopy findings were examined using ex vivo CLSM in reflectance and fluorescence mode following staining with fluorescent-labelled IgG and C3 antibodies. RESULTS: Ex vivo CLSM showed an overall performance of 65.3% in identifying BM fluorescence in BP patients. IgG and C3 deposition along the BM was detected in 50% and 45.5% of the patients, respectively. The sensitivity of ex vivo CLSM in detecting BM fluorescence was low (IgG: 50%, C3: 45.5%), but the specificity was high (IgG: 100, C3: 90%). In addition to immunoreactivity, ex vivo CLSM could display subepidermal inflammatory cells similar to histological examination in 84% of patients. CONCLUSIONS: Basement membrane fluorescence could be identified with ex vivo CLSM in the skin sections of BP patients. Ex vivo CLSM enables simultaneous and rapid detection of histopathological and immunofluorescence findings in the same session, albeit with a lower sensitivity than DIF in detecting BM fluorescence.

Robust label-free biosensing using microdisk laser arrays with on-chip references.

Whispering-gallery mode (WGM) microdisk lasers show great potential for highly sensitive label-free detection in large-scale sensor arrays. However, when used in practical applications under normal ambient conditions, these devices suffer from temperature fluctuations and photobleaching. Here we demonstrate that these challenges can be overcome by a novel referencing scheme that allows for simultaneous compensation of temperature drift and photobleaching. The technique relies on reference structures protected by locally dispensed passivation materials, and can be scaled to extended arrays of hundreds of devices. We prove the viability of the concept in a series of experiments, demonstrating robust and sensitive label-free detection over a wide range of constant or continuously varying temperatures. To the best of our knowledge, these measurements represent the first demonstration of biosensing in active WGM devices with simultaneous compensation of both photobleaching and temperature drift.

The invisible basal cell carcinoma: how reflectance confocal microscopy improves the diagnostic accuracy of clinically unclear facial macules and papules.

Difficult to diagnose and early non-melanoma skin cancer lesions are frequently seen in daily clinical practice. Besides precancerous lesions such as actinic keratosis, basal cell carcinomas (BCCs) score the highest frequency in skin tumors. While infiltrative and nodular BCCs require a surgical treatment with a significant impact on the patients' quality of life, early and superficial BCCs might benefit from numerous conservative treatments, such as topical immune-modulators or photodynamic therapy. Dermoscopy has shown a high sensitivity and specificity in the diagnosis of early BCCs, and non-invasive imaging techniques like reflectance confocal microscopy (RCM) have proven to be helpful. The aim of our study was to investigate the importance of RCM in the diagnosis of BCCs with indistinct clinical and dermoscopic features. We retrospectively examined 27 histologically proven BCCs in which diagnosis was not possible based on naked eye examination; we separately reviewed clinical, dermoscopic, and confocal microscopy features and evaluated the lesions meeting the common diagnostic criteria for BCCs, and our diagnostic confidence. All lesions were clinically unclear, with no characteristic features suggestive for BCC; dermoscopy showed in most cases unspecific teleangiectasias (74 %) and micro-erosions (52 %). Confocal microscopy revealed in most of the cases the presence of specific criteria: peripheral palisading of the nuclei (89 %), clefting (70 %), stromal reaction (70 %), dark silhouettes (70 %), inflammatory particles (70 %), and tumor islands (67 %). In the absence of significant diagnostic clinical signs and with unclear dermoscopic features, specific confocal patterns were present in most of the lesions and enabled a correct diagnosis. In the absence of significant clinical features of BCC and in the case of uncertain dermoscopy, striking confocal features are detectable and easy to recognize in most cases. Confocal microscopy can therefore be instrumentful in the diagnosis of the so-called invisible BCCs.

[Ultrasound for surveillance after endovascular repair of abdominal aortic aneurysm--simple and safe?]. / Welche Nachkontrolle ist bei endovaskulärer Versorgung von abdominellen Aortenaneurysmen empfehlenswert?

In the past, multislice computed tomography angiography (CTA) with arterial and venous phase was recommended as the gold standard in follow-up after endovascular abdominal aneurysm repair (EVAR). Iodine-containing contrast agents and frequent radiation exposure are limitations for use in elderly patients with chronic renal insufficiency. Colour-coded Doppler sonography (CCDS) and, especially, contrast-enhanced ultrasound (CEUS) are non-invasive methods that are time and cost effective. Both provide a reliable alternative to CTA in surveillance after EVAR. CEUS seems to be superior in characterisation of the type of endoleaks and can be established in order to reduce iodine-containing contrast agent and radiation exposure in follow-up. In contrast to CTA scans, CEUS can be offered to patients with chronic renal insufficiency and allows a dynamic examination and perfusion analysis (e. g., in fenestrated and branched stentgrafts). Routine combination with X-ray allows control of stentgraft material and location of the branches.

Blood vitamin concentrations in privately owned dogs fed non-standardized commercial diets and after intake of diets with specified vitamin concentrations.

The objective was to investigate in a survey study the blood vitamin concentrations in healthy dogs fed non-specified commercial complete diets and in an intervention study to determine the effects of defined dietary vitamin intakes on blood vitamin levels and hair and skin condition. Sixty-four privately owned dogs, aged from 1 to 8 years, without history of skin or coat problems were included. All animals were fed commercial complete diets with uncertain vitamin concentrations before enrolment. The animals were assigned, according to weight and gender, to four groups with graded vitamin intakes. The blood vitamin levels and skin and coat quality of the dogs were investigated at days 0 and day 122. Coat and hair condition was not influenced by the experimental diets. The retinol concentrations were reduced at the end of the experiment compared with the baseline levels, retinyl esters were not influenced. 25-Hydroxycholecalciferol decreased in all groups, alpha-tocopherol was constant or tended to decrease. Ascorbic acid, thiamine pyrophosphate and riboflavin concentrations were not affected by treatment, flavin adenine dinucleotide and pyridoxal-5'-phosphate were partially reduced on day 122. Cobalamin, pantothenate and biotin concentrations increased with higher dietary intakes, folate levels in tendency. In conclusion, this study gives a survey of blood vitamin concentrations in healthy dogs and provides a data base for the evaluation of the vitamin status in health and disease.

Quality of life following aesthetic plastic surgery: a prospective study.

BACKGROUND: The objective of this study was the prospective evaluation of quality of life in patients undergoing aesthetic plastic surgery procedures. We examined pre- and postoperative changes in quality of life, and performed a comparison of our data with a representative random sample. METHOD: 228 patients agreed to participate in the present study. Measurements were taken preoperatively as well as 3 and 6 months postoperatively. One hundred and thirty two patients completed the three months postoperative evaluation (T1), 82 answered the 6 months follow-up evaluation (T2). The testing instrument included a standardised self-assessment test on satisfaction and quality of life (FLZ(M)), consisting of three modules: satisfaction with general life, health and appearance. Further, a postoperative complication questionnaire was used in order to evaluate the satisfaction with the surgical outcome and to estimate postoperative complications and side effects. RESULTS: Significantly increasing values in two aspects of quality of life were found: health and appearance. Whereas the positive influence on health is persistent, there is a diminishing influence of appearance 6 months postoperatively. Although higher values for some of the individual items of the FLZ(M) modules of the norm data were found in comparison to our study group, a general preoperative lower level of quality of life of the aesthetic surgery patients could not be confirmed. Over 84% were satisfied or very satisfied with the aesthetic result. 85% would undergo the same treatment again and 94% of the patients would further recommend their operation. More than half of the study group did not report a decrease in physical fitness or reduced social contacts in the direct postoperative period. CONCLUSION: Our study reveals that aesthetic plastic surgery increases most aspects of quality of life, especially regarding body satisfaction and health. It is very well tolerated by the patients and is therefore a recommended option.