Comparing Line-Field Confocal Optical Coherence Tomography and Reflectance Confocal Microscopy on the In Vivo Healing Process of Lesions Induced by Fractional Photothermolysis.

BACKGROUND: The advent of ablative fractional photothermolysis has revolutionized laser dermatology by providing a method to produce well-standardized, precise, and repeatable microscopic lesions. These wounds typically heal within 1-3 weeks, depending on the body site, with a minimal risk of permanent scarring. This positions ablative fractional photothermolysis as an exemplary in vivo model for studying the skin's wound healing processes. OBJECTIVES: This study aims to evaluate and compare the effectiveness of two noninvasive imaging techniques, reflectance confocal microscopy (RCM) and line-field confocal optical coherence tomography (LC-OCT), in assessing skin wound healing following microscopic injuries induced by ablative fractional photothermolysis. METHODS: The forearms of participating volunteers were treated and ablated with a CO2-Laser in a fractional pattern using varying power settings (2.5-10 mJ/MTZ). In vivo RCM and LC-OCT images were obtained at predefined time intervals post-laser treatment, ranging from 6 h to 14 days. RESULTS: Vertical visualization of the lesions through both imaging modalities revealed a healing process characterized by the upward and outward movement of microscopic epidermal necrotic debris, thereby reducing the depth of the injury while forming an external crust. LC-OCT imaging demonstrated more comprehensive results with fewer movement artifacts. Conversely, horizontal visualization with both techniques highlighted a gathering of keratinocytes around the wounds, indicating the initiation of the regenerative process. RCM provided superior image clarity in this horizontal plane. CONCLUSIONS: RCM and LC-OCT offer valuable and complementary noninvasive alternatives to conventional biopsy methods for the assessment and characterization of the skin's wound healing process post-ablative fractional photothermolysis. These findings underscore the potential of such imaging techniques in enhancing our understanding of the wound healing process. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT05614557.

The Efficacy and Safety of CollaSel Pro® Hydrolyzed Collagen Peptide Supplementation without Addons in Improving Skin Health in Adult Females: A Double Blind, Randomized, Placebo-Controlled Clinical Study Using Biophysical and Skin Imaging Techniques.

Background: This study aimed to evaluate the efficacy and safety of oral hydrolyzed collagen peptide (HCP) in healthy females by assessing the skin parameters via biophysical and skin imaging techniques. Methods: 112 females were randomly assigned to receive either HCP (n = 57; 10 g CollaSel Pro®) or placebo (n = 55; 10 g maltodextrin) daily for eight weeks. The contribution of HCP to skin elasticity, hydration, and roughness was investigated against a placebo, while the facial soft tissue sagging (RMS) and safety data were also recorded. Results: HCP was associated with significant improvements in skin elasticity (p = 0.009), skin hydration (p ranged from 0.003 to <0.001), and skin roughness (p ranged from 0.002 to <0.001). In the HCP vs. the placebo group, week eight values for skin elasticity (43.0 (7.4) vs. 40.3 (3.3) mPa, p = 0.017), skin hydration (65.8 (18.9) vs. 53.1 (14.9) g/m3, p < 0.001) and skin roughness (40.2 (20.4) vs. 24.9 (20.9) g/m3, p < 0.001) were significantly higher. In the HCP group, week 8 RMS values were significantly lower than baseline values (1.02 (0.21) vs. 1.10 (0.21) mm, p = 0.012). Conclusions: CollaSel Pro® HCP can be considered a well-tolerated, safe product that effectively improves dermal health and the appearance of sagging and ameliorates the signs of the aging process.

Timing of Laser Intervention on Facial Scars: A 3D Imaging and Scar Scale Analysis in a Retrospective Study.

OBJECTIVES: Scars resulting from injuries or surgical procedures often present both physical and aesthetic challenges. Recent studies have indicated promising results in improving postoperative scar outcomes through the combined use of specific laser technologies. Nevertheless, there remains a crucial need for further exploration to ascertain the optimal timing for initiating such treatments. METHODS: In this retrospective investigation, a cohort of 47 adult patients who did not require hospitalization was analyzed. These patients were divided into two distinct groups: Group A, which received intervention beginning 2 weeks after their respective operations, and Group B, which commenced intervention 4 weeks postoperation. Each group underwent a comprehensive treatment protocol consisting of five laser sessions. Initially, patients underwent three sessions of V-beam pulsed-dye laser (PDL) therapy followed by two sessions of ablative fractional CO2 laser (AFL) therapy. Evaluation of outcomes was conducted using advanced imaging techniques such as Antera 3D imaging, in conjunction with established scar assessment tools including the Vancouver Scar Scale (VSS) and the University of North Carolina "4P" Scar Scale (UNC4P). RESULTS: All patients successfully completed the full course of five treatment sessions, with no dropouts and no reported adverse events. Baseline cosmetic assessments of scars were equivalent across both groups. In Group A, the mean VSS scores decreased from 7.04 before treatment to 5.29 at 3 months posttreatment and further to 4.33 at 6 months posttreatment. Meanwhile, in Group B, scores decreased from 7.52 to 6.83 at 3 months and 6.17 at 6 months. There were no statistically significant differences in baseline VSS scores between the two groups (p = 0.34). At both the 3- and 6-month follow-up points, mean VSS scores were significantly lower in Group A compared to Group B (p < 0.05). Similar trends were observed in UNC4P scores. Statistically significant differences were noted across all time points (baseline, 3 months, and 6 months posttreatment) for both VSS and UNC4P scores (p < 0.05). Subset analysis revealed greater improvements in texture and depression volume at 3 months posttreatment, while improvements in depression area, depth, elevation variation, and area were more pronounced at the 6-month mark. CONCLUSIONS: Early intervention using the combined 595-nm pulse dye laser and CO2 ablative fractional laser (AFL) 2- and 4-weeks post-surgery proves to be an effective and safe method for improving scar outcomes, particularly for facial surgical scars when treatment starts 2 weeks after surgery. However, further research is needed to refine our understanding and address potential study limitations.

Radiomic and deep learning analysis of dermoscopic images for skin lesion pattern decoding.

This study aims to explore the efficacy of a hybrid deep learning and radiomics approach, supplemented with patient metadata, in the noninvasive dermoscopic imaging-based diagnosis of skin lesions. We analyzed dermoscopic images from the International Skin Imaging Collaboration (ISIC) dataset, spanning 2016-2020, encompassing a variety of skin lesions. Our approach integrates deep learning with a comprehensive radiomics analysis, utilizing a vast array of quantitative image features to precisely quantify skin lesion patterns. The dataset includes cases of three, four, and eight different skin lesion types. Our methodology was benchmarked against seven classification methods from the ISIC 2020 challenge and prior research using a binary decision framework. The proposed hybrid model demonstrated superior performance in distinguishing benign from malignant lesions, achieving area under the receiver operating characteristic curve (AUROC) scores of 99%, 95%, and 96%, and multiclass decoding AUROCs of 98.5%, 94.9%, and 96.4%, with sensitivities of 97.6%, 93.9%, and 96.0% and specificities of 98.4%, 96.7%, and 96.9% in the internal ISIC 2018 challenge, as well as in the external Jinan and Longhua datasets, respectively. Our findings suggest that the integration of radiomics and deep learning, utilizing dermoscopic images, effectively captures the heterogeneity and pattern expression of skin lesions.

An Update on Non-Invasive Skin Imaging Techniques in Actinic Keratosis-A Narrative Review.

Nonmelanocytic skin cancers (NMSCs) are currently the most common group of human cancers and include all tumors that are not melanomas. Increased exposure to sunlight over the past few years, the lack of regular and proper use of sunscreen, the aging of the population, and better screening techniques are the reasons for the escalation in their diagnosis. Squamous cell carcinoma (SCC) comprises nearly 37% of the tumors in this group and can originate from actinic keratosis (AK), which usually presents as pink, often scaly plaques, usually located on the face or scalp. Advances in dermatoscopy, as well as the development of other non-invasive skin imaging modalities such as high-frequency ultrasound (HFUS), reflectance confocal microscopy (RCM), and optical coherence tomography (OCT), have allowed for greatly increased sensitivity in diagnosing these lesions and monitoring their treatment. Since AK therapy is usually local, and SCCs must be removed surgically, non-invasive imaging methods enable to correctly qualify difficult lesions. This is especially important given that they are very often located on the face, and achieving an appropriate cosmetic result after treatments in this area is very important for the patients. In this review, the authors describe the use of non-invasive skin imaging methods in the diagnosis of actinic keratosis.

High-frequency photoacoustic and ultrasound imaging for skin evaluation: Pilot study for the assessment of a chemical burn.

Skin architecture and its underlying vascular structure could be used to assess the health status of skin. A non-invasive, high resolution and deep imaging modality able to visualize skin subcutaneous layers and vasculature structures could be useful for determining and characterizing skin disease and trauma. In this study, a multispectral high-frequency, linear array-based photoacoustic/ultrasound (PAUS) probe is developed and implemented for the imaging of rat skin in vivo. The study seeks to demonstrate the probe capabilities for visualizing the skin and its underlying structures, and for monitoring changes in skin structure and composition during a 5-day course of a chemical burn. We analayze composition of lipids, water, oxy-hemoglobin, and deoxy-hemoglobin (for determination of oxygen saturation) in the skin tissue. The study successfully demonstrated the high-frequency PAUS imaging probe was able to provide 3D images of the rat skin architecture, underlying vasculature structures, and oxygen saturation, water, lipids and total hemoglobin.

A systematic review investigating the proportion of clinical images shared in prospective randomized controlled trials involving patients with atopic dermatitis and systemic pharmacotherapy.

For individuals with atopic dermatitis (AD), interpreting scientific papers that present clinical outcomes including the Eczema Area and Severity Index (EASI) and Investigators Global Assessment may be difficult. When compared to tabulated data and graphs, images from before and after treatment are often far more meaningful to these patients that ultimately will be candidates for the treatment. This systematic review focused on determining the frequency of clinical image sharing in AD research.Conducted in accordance with PRISMA guidelines, the review concentrated on randomized controlled trials that investigated predefined and available systemic treatments for AD. The search was performed in the MEDLINE database for studies published from the inception until 21 December 2023.The review included 60 studies, encompassing 17,799 randomized patients. Across these studies, 16 images representing 6 patients were shared in the manuscripts, leading to a sharing rate of 0.3‰.The almost missing inclusion of patient images in clinical trial publications hinders patient understanding. Adding images to scientific manuscripts could significantly improve patients' comprehension of potential treatment outcomes. This review highlights the need for authors, the pharmaceutical industry, study sponsors, and publishers to enhance and promote patient information through increased use of visual data.

Quality control in clinical raster-scan optoacoustic mesoscopy.

Optoacoustic (photoacoustic) mesoscopy bridges the gap between optoacoustic microscopy and macroscopy and enables high-resolution visualization deeper than optical microscopy. Nevertheless, as images may be affected by motion and noise, it is critical to develop methodologies that offer standardization and quality control to ensure that high-quality datasets are reproducibly obtained from patient scans. Such development is particularly important for ensuring reliability in applying machine learning methods or for reliably measuring disease biomarkers. We propose herein a quality control scheme to assess the quality of data collected. A reference scan of a suture phantom is performed to characterize the system noise level before each raster-scan optoacoustic mesoscopy (RSOM) measurement. Using the recorded RSOM data, we develop a method that estimates the amount of motion in the raw data. These motion metrics are employed to classify the quality of raw data collected and derive a quality assessment index (QASIN) for each raw measurement. Using simulations, we propose a selection criterion of images with sufficient QASIN, leading to the compilation of RSOM datasets with consistent quality. Using 160 RSOM measurements from healthy volunteers, we show that RSOM images that were selected using QASIN were of higher quality and fidelity compared to non-selected images. We discuss how this quality control scheme can enable the standardization of RSOM images for clinical and biomedical applications.

Digitally Enhanced Methods for the Diagnosis and Monitoring of Treatment Responses in Actinic Keratoses: A New Avenue in Personalized Skin Care.

Non-melanocytic skin cancers represent an important public health problem due to the increasing incidence and the important local destructive potential. Thus, the early diagnosis and treatment of precancerous lesions (actinic keratoses) is a priority for the dermatologist. In recent years, non-invasive skin imaging methods have seen an important development, moving from simple observational methods used in clinical research, to true diagnostic and treatment methods that make the dermatologist's life easier. Given the frequency of these precancerous lesions, their location on photo-exposed areas, as well as the long treatment periods, with variable, imprecise end-points, the need to use non-invasive imaging devices is increasingly evident to complete the clinical observations in the diagnosis and treatment of these lesions, with the aim of increasing accuracy and decreasing the adverse effects due to long treatment duration. This is the first review that brings together all skin imaging methods (dermoscopy, reflectance confocal microscopy, ultrasonography, dermoscopy-guided high frequency ultrasonography, and optical coherence tomography) used in the evaluation of actinic keratoses and their response to different treatment regimens.

Pre-operative high-frequency ultrasound: a reliable management tool in auricular and nasal non-melanoma skin cancer.

BACKGROUND AND OBJECTIVES: The knowledge of depth infiltration in non-melanoma skin cancer (NMSC) using pre-operative ultrasound could enable clinicians to choose the most adequate therapeutic approach, avoiding unnecessary surgeries and expensive imaging methods, delaying diagnosis and treatment. Our single-center retrospective study determined the usefulness of high-frequency ultrasound (HFUS) for depth infiltration assessment in auricular and nasal NMSC and assessed the subsequent change in therapeutic approach. PATIENTS AND METHODS: In 60 NMSC cases, we assessed the accuracy of HFUS in cartilaginous/bone infiltration detection as well as the correlation of sonographic and histological parameters. RESULTS: In 16.6% of cases, a deep cartilaginous/bone involvement or locoregional disease was identified pre-operatively, resulting in a changed therapeutical scheme of radio-immunological treatment rather than surgery. In two cases, pre-operative HFUS identified local cartilage infiltration, reducing the number of surgical procedures. Forty-eight remaining lesions with no depth infiltration were excised; a correlation of > 99% between the histologic and sonographic tumor depth (p<0.001) was found. CONCLUSIONS: Pre-surgical HFUS influences the therapeutic management in NMSC by detecting subclinical involvement of deeper structures, avoiding more extensive diagnostics, reducing costs, and improving healthcare quality. High-frequency ultrasound should be implemented in dermatosurgery before tumor excision for optimized therapy and improved patient counseling.

4D spectral-spatial computational photoacoustic dermoscopy.

Photoacoustic dermoscopy (PAD) is an emerging non-invasive imaging technology aids in the diagnosis of dermatological conditions by obtaining optical absorption information of skin tissues. Despite advances in PAD, it remains unclear how to obtain quantitative accuracy of the reconstructed PAD images according to the optical and acoustic properties of multilayered skin, the wavelength and distribution of excitation light, and the detection performance of ultrasound transducers. In this work, a computing method of four-dimensional (4D) spectral-spatial imaging for PAD is developed to enable quantitative analysis and optimization of structural and functional imaging of skin. This method takes the optical and acoustic properties of heterogeneous skin tissues into account, which can be used to correct the optical field of excitation light, detectable ultrasonic field, and provide accurate single-spectrum analysis or multi-spectral imaging solutions of PAD for multilayered skin tissues. A series of experiments were performed, and simulation datasets obtained from the computational model were used to train neural networks to further improve the imaging quality of the PAD system. All the results demonstrated the method could contribute to the development and optimization of clinical PADs by datasets with multiple variable parameters, and provide clinical predictability of photoacoustic (PA) data for human skin.

Line-Field Confocal Optical Coherence Tomography (LC-OCT) for Skin Imaging in Dermatology.

Line-field confocal optical coherence tomography (LC-OCT) is a non-invasive optical imaging technique based on a combination of the principles of optical coherence tomography and reflectance confocal microscopy with line-field illumination, which can generate cell-resolved images of the skin in vivo. This article reports on the LC-OCT technique and its application in dermatology. The principle of the technique is described, and the latest technological innovations are presented. The technology has been miniaturized to fit within an ergonomic handheld probe, allowing for the easy access of any skin area on the body. The performance of the LC-OCT device in terms of resolution, field of view, and acquisition speed is reported. The use of LC-OCT in dermatology for the non-invasive detection, characterization, and therapeutic follow-up of various skin pathologies is discussed. Benign and malignant melanocytic lesions, non-melanocytic skin tumors, such as basal cell carcinoma, squamous cell carcinoma and actinic keratosis, and inflammatory and infectious skin conditions are considered. Dedicated deep learning algorithms have been developed for assisting in the analysis of LC-OCT images of skin lesions.

Multispectral Imaging Analysis of Skin Lesions in Patients with Neurofibromatosis Type 1.

Neurofibromatosis type 1 (NF1) is a rare disease, affecting around 1 in 3500 individuals in the general population. The rarity of the disease contributes to the scarcity of the available diagnostic and therapeutic approaches. Multispectral imaging is a non-invasive imaging method that shows promise in the diagnosis of various skin diseases. The device utilized for the present study consisted of four sets of narrow-band LEDs, including 526 nm, 663 nm, and 964 nm for diffuse reflectance imaging and 405 nm LEDs, filtered through a 515 nm long-pass filter, for autofluorescence imaging. RGB images were captured using a CMOS camera inside of the device. This paper presents the results of this multispectral skin imaging approach to distinguish the lesions in patients with NF1 from other more common benign skin lesions. The results show that the method provides a potential novel approach to distinguish NF1 lesions from other benign skin lesions.

A systematic review investigating at what proportion clinical images are shared in prospective randomized controlled trials involving patients with psoriasis and biological agents.

For many patients including those with psoriasis, scientific manuscripts comprising clinical outcomes including psoriasis area severity index (PASI) and/or physician global assessment (PGA) may be difficult to understand. However, most patients can relate to images at baseline and follow-up, particularly for dermatological diseases. This study aimed to assess the proportion of shared clinical images in psoriasis trials. A systematic review adhering to the PRISMA guidelines was performed. The review was limited to randomized controlled trials, and among these, only investigations involving biological agents for treatment of psoriasis were included. The Embase, MEDLINE and Scopus databases were searched for eligible studies published from inception to October 26, 2021. In total, 152 studies were included. When combining these, 62,871 patients were randomized. Overall, 203 images were shared depicting 60 patients in the manuscripts yielding an overall sharing rate of 0.1%. Patient images are seldom incorporated in clinical trial manuscripts which impairs interpretation for patients. Inclusion of image material would strengthen the patients' perspective and understanding on what treatment effects that can be expected. As such, this systematic review should be an invitation to the pharmaceutical industry, other sponsors, and editorial offices to improve easy transfer of information to patients using image data.

Handheld cross-polarised microscope for imaging individual pigmented cells in human skin in vivo.

We present the development of a simple, handheld cross-polarised microscope (CPM) and demonstration of imaging individual pigmented cells in human skin in vivo. In the CPM device, the cross-polarised detection approach is used to reduce the specular reflection from the skin surface and preferentially detect multiply-scattered light. The multiply-scattered light works as back illumination from within the tissue towards the skin surface, and superficial pigment such as intraepidermal melanin absorbs some spectral bands of the multiply-scattered light and cast coloured shadows. Since the light that interacted with the superficial pigment only needs to travel a short distance before it exits the skin surface, microscopic details of the pigment can be preserved. The CPM device uses a water-immersion objective lens with a high numerical aperture to image the microscopic details with minimal spherical aberrations and a small depth of focus. Preliminary results from a pilot study of imaging skin lesions in vivo showed that the CPM device could reveal three-dimensional distribution of pigmented cells and intracellular distribution of pigment. Co-registered CPM and reflectance confocal microscopy images showed good correspondence between dark, brown cells in CPM images and bright, melanin-containing cells in reflectance confocal microscopy images.