Search Results (297)

Background/Objectives: Facial discoid dermatosis is a rare inflammatory dermatosis presenting with round, superficial erythematous lesions located on the face. Diagnosis may be challenging and often requires careful clinicopathological correlation due to overlapping clinical and histopathological features. Skin lesions are typically resistant to a wide range of topical and systemic treatments. From the perspective of personalized medicine, improved phenotyping of rare inflammatory dermatoses may support more precise diagnosis, individualized therapeutic decisions, and non-invasive disease monitoring. This study aimed to characterize facial discoid dermatosis using line-field confocal optical coherence tomography and reflectance confocal microscopy and to discuss its differential diagnosis and therapeutic implications. Methods: We report a case of facial discoid dermatosis in a 35-year-old patient examined with line-field confocal optical coherence tomography and reflectance confocal microscopy. The imaging findings were interpreted in correlation with clinical and histopathological features. A literature review was performed to summarize differential diagnoses, therapeutic perspectives, and the proposed relationship between facial discoid dermatosis and pityriasis rubra pilaris. Results: Non-invasive imaging revealed morphological features consistent with a psoriasiform inflammatory dermatosis and provided additional in vivo information supporting the diagnosis. The literature review showed limited evidence for a direct association between facial discoid dermatosis and pityriasis rubra pilaris, with only isolated reports suggesting possible overlap or progression. Conclusions: Facial discoid dermatosis appears to represent a distinct psoriasiform dermatosis. Line-field confocal optical coherence tomography and reflectance confocal microscopy may contribute to a personalized diagnostic approach by supporting differential diagnosis and potentially guiding individualized monitoring in rare inflammatory facial dermatoses. Full article

Magnetic resonance imaging (MRI) uses radiofrequency (RF) energy to generate diagnostic images. RF–tissue interactions lead to energy absorption and tissue heating, quantified by the specific absorption rate (SAR). Although SAR limits are strictly regulated for patient safety, actual in vivo tissue temperature changes during clinical MRI examinations in humans have not been directly measured. A patient with a histologically confirmed soft tissue sarcoma of the thigh underwent a clinically indicated 3 T MRI examination 24 h prior to resection. During imaging with whole-body SAR of 2.27 W/kg, direct temperature measurements (invasive and on the skin) were obtained. Temperatures increased by 2.0 °C within the tumor and at the skin surface was 3.4 °C at the skin surface. No technical difficulties or adverse events were observed, and the patient tolerated the examination well. This first-in-human case demonstrates the feasibility and safety of direct intratumoral temperature measurement during standard 3T MRI. While MRI was performed within safety limits of SAR as a surrogate for true tissue temperature, non-invasive temperature monitoring during MRI needs improvement. Controlled RF-induced heating during MRI may open new therapeutic possibilities, including MR-guided hyperthermia for sarcomas and other solid tumors or modulation of blood–brain barrier through transient RF-induced temperature elevations facilitating drug delivery. Full article

Medical infrared thermography, which involves the use of infrared thermal cameras for the non-invasive assessment of skin surface temperature distribution, has gained increasing interest in recent years as a tool supporting diagnosis and treatment monitoring. The aim of this article is to present the historical background and critically reassess the current role of infrared thermography in medicine, with particular emphasis on standardization as a key determinant of its clinical utility. This Perspective highlights the fundamental impact of methodological variability on diagnostic performance and reproducibility. A structured framework for standardization is proposed, encompassing patient preparation, environmental conditions, device parameters and calibration, image acquisition protocols, region-of-interest definition and analysis, as well as reporting and clinical interpretation. The analysis demonstrates how inconsistencies at each of these levels reduce measurement reliability, limit inter-study comparability, and weaken clinical confidence in infrared thermography. The article also addresses the growing availability of mobile thermal imaging systems and their integration with artificial intelligence, while emphasizing the need for stronger evidence-based support across all methodological domains. The presented analysis suggests that, despite existing limitations, medical infrared thermography holds considerable potential as a supportive clinical tool. However, its broader clinical implementation remains limited by several factors, with the lack of standardized protocols constituting a major and practically addressable translational barrier. Wider adoption will require standardization efforts alongside rigorous validation studies and application-specific interpretative guidelines. Addressing these challenges through technological advances and coordinated international standardization may facilitate meaningful progress over the next decade. Full article

Background/Objectives: Merkel cell carcinoma (MCC) is a rare but aggressive skin cancer with a 40% recurrence rate. However, reliable biomarkers for early recurrence detection or treatment guidance are lacking, especially for virus-negative tumors. Circulating tumor DNA (ctDNA), a fragment of tumor-derived cell-free DNA in blood, has emerged across multiple cancers as a minimally invasive precision biomarker to detect minimal residual disease (MRD); predict recurrence; and monitor treatment response. This review’s objective was to summarize recent advances in ctDNA as a tool for therapeutic decision-making in MCC, contextualized by findings in other malignancies. Methods: A comprehensive literature review was performed, focusing on studies published between 2016 and 2026 that evaluate ctDNA in MCC and other cancers. Key prospective trials, observational studies, and case reports were identified through PubMed and relevant conference proceedings. Data on ctDNA assay methods (tumor-informed vs. tumor-agnostic), clinical sensitivity, lead time for recurrence detection, and predictive value for therapy response were extracted and synthesized. Results: Across cancers such as colorectal, lung, and melanoma, ctDNA positivity after curative treatment predicts relapse months in advance of imaging and can guide adjuvant therapy decisions. In MCC, recent studies demonstrate that ctDNA levels correlate with MCC tumor burden and exhibit high sensitivity and specificity for clinically evident disease. Stage I-III MCC patients who were ctDNA-positive within four months of treatment had a 7.4-fold higher recurrence risk within the subsequent 12–18 months of follow-up. Serial ctDNA monitoring may enable earlier intervention in otherwise asymptomatic ctDNA-positive MCC cases, helping distinguish responders from non-responders. Conclusions: ctDNA is an emerging precision biomarker that offers significant prognostic and surveillance utility in MCC. It enables earlier detection of recurrence, potentially allowing treatment to begin before clinical disease manifests. It also helps stratify patients by risk and treatment response, informing personalized surveillance intensity and therapeutic choices. Integrating ctDNA monitoring into MCC management could improve outcomes by guiding timely interventions, although prospective trials are needed to confirm that ctDNA-guided decisions translate to improved patient survival. Formal cost-effectiveness analyses have not yet been conducted and represent an important area for future investigation. Full article

Optical coherence tomography (OCT) is an optical imaging modality that provides high-resolution cross-sectional imaging of biological tissues noninvasively. In Fourier-domain OCT, axial resolution is governed by both the center wavelength and the spectral bandwidth of the light source; therefore, limited or discontinuous bandwidth degrades depth resolution and introduces sidelobes and artifacts in OCT images. To address these issues in OCT image reconstruction from gapped spectra, a sparse parameter estimation approach based on Sparse Iterative Covariance-based Estimation (SPICE) is proposed in this study. By utilizing a sparse parameter estimation framework to directly resolve depth-dependent components from discontinuous interferograms, SPICE enhances axial resolution while suppressing sidelobe artifacts inherent in standard interpolation. Experiments on multi-layered tape, oral epithelium, and finger skin show that SPICE visually suppresses gap-induced sidelobe artifacts and improves structural interpretability under representative gap conditions. Quantitative evaluations on multi-layer tape and biological tissues show that SPICE reduces axial FWHM by 30–45%, increases SSIM by 0.15–0.25, and achieves significantly lower computational cost than GAPES (p < 0.01). Full article

This paper focuses on the significant potential of specific optical non-invasive methods, such as digital holographic microscopy, digital speckle pattern interferometry, and digital holographic interferometry, as scientific and technological tools for retrieving physical and biomechanical parameters embedded in the optical phase of laser-illuminated biomedical samples. These techniques take advantage of the laser speckle phenomena observed when non-specular surfaces are illuminated, enabling whole-field measurements and reconstruction of 3D images. Their versatility in implementation and application has led to advances in various fields of research and has broadened our understanding in both the basic and applied sciences. In clinical environments, the aforementioned quantitative optical studies are particularly valuable for understanding the behavior of biological samples, as they allow precise characterization of deformations, displacements, stress, strain, refractive index, and morphological features. Applications presented span from soft to hard tissues at both micro- and macro-scales, with results obtained from vocal cords, skin tissues, melanoma cells, and teeth. Furthermore, this overview provides a general perspective of some current speckle-based approaches and their growing relevance in biomedical research. Full article

Neuropathic pain is a debilitating condition lacking objective and quantitative assessment tools, as current evaluations rely largely on subjective reports. Hyperspectral imaging (HSI) is a non-invasive technology that quantifies spatial and spectral tissue characteristics and has been applied in rheumatologic and metabolic disorders. This study investigated whether HSI-detected paw skin alterations correlate with graded nerve injury severity in a chronic constriction injury (CCI) model. Sprague–Dawley rats were assigned to sham or CCI groups with one to four sciatic nerve ligatures. Behavioral assessments (CatWalk XT gait analysis, thermal hyperalgesia, and mechanical allodynia) and paw HSI measurements were performed longitudinally. Histological and molecular analyses were conducted from paw skin to dorsal spinal cord tissues. At 1100 nm, HSI demonstrated progressive and significant spectral deviations proportional to injury severity across all CCI groups, whereas 1300 nm changes were only detected in severe injuries. Histology revealed increased fibrosis, NGF, TNF-α, synaptophysin, and microglial activation with greater injury severity, alongside reduced PGP9.5, neurofilament, AChR, Desmin, GAP-43, Pax3, and BDNF expression. These molecular findings were supported by electrophysiological and behavioral impairments, which correlated with injury grade by HSI. In conclusion, HSI at 1100 nm provides a sensitive and objective indicator of neuropathic pain severity and holds promise as a quantitative translational tool. Full article

Background/Objectives: Accurate differentiation of benign melanocytic nevi from invasive melanoma in dermato-oncology directly informs biopsy decisions and oncological management. Vision–language models (VLMs) are increasingly explored for image-based skin cancer assessment, but their diagnostic reliability and robustness to adversarial input manipulation remain insufficiently characterized. We evaluated three contemporary VLMs for diagnostic performance and susceptibility to single-word adversarial input manipulation (prompt injection) on dermoscopic images of histopathologically confirmed lesions. Methods: Fifty-two dermoscopic images (26 benign melanocytic nevi, 26 invasive melanomas) were analyzed using Claude Opus 4.7, Gemini 3.1 Pro, and GPT-5.4 under four conditions: an unmodified baseline and three adversarial conditions with a single opposite-of-ground-truth label embedded as a visual overlay, in image metadata, or both. Three independent rounds per image × model × condition yielded 1872 classifications across 52 lesions (independent diagnostic units) and 16,848 structured-output observations in total. Results: Baseline diagnostic accuracy ranged from 58.3% to 62.2%, with asymmetric sensitivity and specificity, including a pronounced benign-labeling bias in one model that missed 22 of 26 invasive melanomas. All adversarial conditions reduced accuracy to near-zero levels (0.0–1.9%; all p < 10⁻⁷ after Bonferroni correction). Repeated queries produced identical incorrect outputs in 98–100% of cases (Fleiss’ κ 0.97–1.00). Non-diagnostic outputs remained largely unchanged, and self-reported confidence did not decrease. Conclusions: Contemporary VLMs show limited baseline performance and marked vulnerability to minimal adversarial input in dermoscopic skin cancer assessment. The failure selectively alters the malignancy decision while preserving surrounding outputs and confidence, indicating that, within the conditions evaluated here, these systems do not currently appear suitable for unsupervised clinical use in dermato-oncology in the absence of input-integrity safeguards and qualified human oversight. Full article

Background and Clinical Significance: Primary cutaneous anaplastic large cell lymphoma (C-ALCL) is a CD30-positive T-cell lymphoproliferative disorder that can clinically resemble various non-melanoma skin cancers, making diagnosis challenging. Although histopathology remains the diagnostic gold standard, non-invasive imaging modalities such as dermoscopy and reflectance confocal microscopy (RCM) are increasingly used as complementary tools to support the differential diagnosis. To date, no data on RCM features of C-ALCL have been described. Case Presentation: We report the case of an 80-year-old man presenting with a rapidly enlarging nodule on the lateral aspect of his right eyelid, providing a detailed account of dermoscopic and RCM findings integrated with clinicopathological correlation. Dermoscopy revealed a red-orange homogeneous background with white streaks, and polymorphic vascular structures, while subsequent RCM (Vivascope 3000 probe) demonstrated marked architectural disarray of the epidermis and dermoepidemal junction, with prominent epidermal involvement characterized by aggregates of highly reflective cells. In the absence of alternative diagnostic patterns, these features raised suspicion for a cutaneous lymphoproliferative disorder, which was later confirmed by histopathological and immunohistochemical analyses. Conclusions: Our findings support the value of RCM as a practical tool in guiding differential diagnosis and biopsy, particularly for rapidly growing lesions located in anatomically sensitive areas. Full article

This preliminary study explored circadian variations in meridian-associated skin temperature using infrared thermal imaging (IRTI). Four healthy adults receive a two-hour IRTI measurement alternately over a 24 h period, with thermal images acquired every 15 min. Within the 24 h monitoring period, two-hour intervals corresponding to the predicted peak activity of each meridian according to the ziwu-liuzhu theory were selected for detailed analysis. Specifically, jing-well acupoints exhibited an early increase in temperature at the onset of their predicted active intervals, whereas terminal acupoints showed a decline in temperature, suggesting the initiation and completion of meridian activity. A progressive increase followed by a decrease was observed along both the spleen meridian (9:00–11:00 a.m.) and heart meridian (11:00–1:00 p.m.), suggesting a temporal trend that may be consistent with traditional Chinese medicine (TCM) predictions. These preliminary results indicate that IRTI may provide a non-invasive approach for visualizing circadian features of meridian function, offering potential to bridge TCM concepts with modern biomedical approaches. Full article

This work presents a noninvasive imaging method to locate veins using a tuned microwave loop resonator. It offers a low-cost, fast, and effective solution to the challenges in venipuncture. The sensor features a loop resonator with a 5.2 mm radius, incorporating a self-tuning mechanism, and operates at 2.408 GHz with a reflection coefficient of −48.77 dB. It generates localized high-intensity electric fields that penetrate tissues to sufficient depths, enabling the detection of veins based on shifts in resonant frequencies that are induced by the varied dielectric properties of blood vessels. Two-dimensional raster scan simulations of the cephalic and median cubital veins yielded a ∼25 MHz downward resonant-frequency shift between vein and non-vein positions, with the median cubital vein still detectable at depths up to 6 mm. To quantify generalization to real tissues, a decision tree classifier trained on 63 simulation samples and evaluated on 335 in vivo measurements achieved 82.09% classification accuracy (sensitivity 81.25%, specificity 83.02%), demonstrating that the simulation-derived frequency contrast transfers reliably to experimental data despite inter-subject tissue variability. Extensive tests conducted demonstrate the sensor’s effectiveness, producing consistent and distinguishable frequency shifts when the sensor moves on the skin across veins. This technology holds significant promise for improving venipuncture accuracy, minimizing complications, and enhancing patient comfort. Full article

Background: Centella asiatica has been widely recognized for its dermatological benefits; however, clinical evidence supporting the efficacy of oral supplementation for improving skin aging parameters remains limited. This randomized, double-blind, placebo-controlled study evaluated the effects of oral Centella asiatica extract on skin wrinkles and related skin parameters in middle-aged women. Methods: A total of 112 participants were randomized to receive either Centella asiatica extract (200 mg/day) or placebo for 12 weeks. Skin wrinkle parameters were quantitatively assessed using a three-dimensional skin imaging system (PRIMOS^®). Skin hydration, transepidermal water loss (TEWL), elasticity, and skin color (brightness and redness) were additionally measured using validated non-invasive instruments. Efficacy analyses were performed in the per-protocol population. Results: After 12 weeks of supplementation, the Centella asiatica extract group demonstrated significant improvements in multiple wrinkle parameters compared with the baseline. Average wrinkle depth decreased by 11.1%, and the mean depth of the largest wrinkle decreased by 14.4%. Maximum wrinkle depth and total wrinkle volume were reduced by 13.3% and 13.7%, respectively, while surface roughness (Ra) decreased by 10.4%. In contrast, the placebo group showed minimal or inconsistent changes. Epidermal hydration at the cheek site significantly increased, while transepidermal water loss decreased, indicating improved skin barrier function. However, the magnitude of changes in epidermal hydration (2.7%), skin elasticity (R2; 0.7%), and skin brightness (L*; 0.7%) were relatively small. Skin elasticity and skin brightness showed statistically significant differences compared with the placebo group (p < 0.05), but these changes should be interpreted as modest improvements. No serious adverse events were reported, and all hematological and biochemical safety markers remained within normal reference ranges during the 12-week intervention period. Conclusions: Oral supplementation with Centella asiatica extract for 12 weeks was associated with improvements in wrinkle-related parameters and TEWL, while changes in skin hydration, elasticity, and brightness were modest and of limited magnitude. These findings suggest a potential role for short-term supplementation; however, further studies are required to confirm long-term efficacy and broader applicability. Full article

Intensive salmon farming is associated with high mortality rates, highlighting the need for new welfare indicators that can detect adverse conditions earlier and less invasively than many current approaches. Existing animal-based indicators used in the industry typically depend on subjective scoring and provide information mostly after welfare problems have already developed, thereby raising questions about their efficacy. Examples include emaciation, wounds, or scale loss, etc. Preliminary data and ongoing investigation suggest that melanin-based skin pigmentation may change dynamically with stress and condition in salmonid fishes. In this study, we present a semi-automated methodology for assessing changes in the grayscale intensity of melanin-based skin spots within the operculum region of adult Atlantic salmon (Salmo salar) kept in seawater. The pipeline combines computer vision models to detect the operculum, segment individual spots, and extract grayscale-based features for spot-level analysis over time. The method was applied to out-of-water images collected before and after exposure to a confinement episode. The results showed an overall shift in grayscale intensity from black to pigmentation fading after the challenge, although responses varied among individuals. These findings indicate that the proposed methodology can detect temporal changes in opercular melanin-based spots under applied experimental conditions. We therefore present this work as proof of principle for using computer vision to quantify changes in melanin-based skin spots as a potentially useful, non-invasive indicator of stress and welfare in Atlantic Salmon. Full article

Hair loss, particularly androgenetic alopecia (AGA) and alopecia areata (AA), is a prevalent condition with widespread psychosocial impact. Recently, low-level laser therapy (LLLT) has emerged as a promising non-invasive therapeutic alternative due to its bioregulatory effects and favorable safety profile compared to conventional pharmacological treatments. In this study, we employed fluorescence lifetime imaging microscopy (FLIM) to investigate the effects of red-light irradiation on hair follicle dynamics and the cutaneous microenvironment in a C57BL/6 mouse model. A hair regeneration model was established to evaluate the efficacy of 650 nm red-light irradiation (bandwidth ± 20 nm). Then, the skin tissue was stained with hematoxylin and eosin (H&E) and followed by FLIM analysis to provide a multidimensional assessment of tissue morphology and metabolic status. Results showed that red-light irradiation significantly increased hair follicle numbers and enhanced adenosine triphosphate (ATP) levels in the skin tissue. FLIM analysis further revealed prolonged fluorescence lifetime values across different epidermal and dermal layers in the irradiated group, indicating significant alterations in the skin metabolic microenvironment. Furthermore, phasor plot analysis enabled precise differentiation between hair follicles and their surrounding skin structures, highlighting FLIM’s high sensitivity and accuracy in evaluating hair growth. In conclusion, this study has provided novel imaging-based insights into the mechanisms of LLLT-induced hair regeneration, highlighting the potential of FLIM as a powerful tool for characterizing the cutaneous microenvironment and quantitatively evaluating phototherapeutic efficacy in future translational applications. Full article

Zygomatic implant perforated (ZIP) flap reconstruction offers immediate surgical rehabilitation following maxillectomy, integrating oncologic zygomatic implants with a fascio-cutaneous free flap. A critical technical challenge is safely perforating the free flap skin paddle to accommodate implants’ abutments without damaging its vasculature. Near-infrared (NIR) vein visualization technology provides real-time mapping of subcutaneous vessels and has been widely investigated in settings such as pediatric intravenous (IV) cannulation. By projecting vein pathways onto the skin, NIR visualization facilitates precise vascular identification, potentially reducing complications. We describe a case of ZIP flap reconstruction in a 25-year-old patient utilizing NIR vein visualization to preemptively locate flap vasculature and minimize the risk of vessel puncture. Our discussion places these findings within the context of the existing literature on NIR devices, underscoring their benefits of non-invasive operation, rapid imaging, and minimal need for advanced operator skills, and highlighting their utility in microvascular reconstructive surgery. Full article