Dataset of human skin and fingernails images for non-invasive haemoglobin level assessment.

Anaemia, a decrease in total concentration of haemoglobin (Hb) in blood, affects substantial percentage of the population worldwide. Currently, the gold standard for determining the Hb level is the invasive analysis of venous blood. Yet, more and more research groups demonstrate the possibility of non-invasive Hb assessment using white light imaging of tissue sites where Hb is the main chromophore, in particular, fingernails. Despite the promising declarations, non-invasive Hb assessment via RGB-imaging is still poorly used in practice. The main reason is the difficulty in establishing the true accuracy of the methods presented in different works since they are tested on private datasets collected under different experimental conditions. Here we present an open dataset containing RGB images of skin and fingernails for patients with a known level of Hb, thus providing a single benchmark for researchers and engineers in the field, aimed at fostering translation of non-invasive imaging methods to the bedside.

Nailfold Video-Capillaroscopy in Sarcoidosis: New Perspectives and Challenges.

INTRODUCTION: Nailfold video-capillaroscopy (NVC) is a non-invasive cost-effective technique involving the microscopic examination of small blood vessels of the distal nailfold with a magnification device. It provides valuable information regarding the microcirculation including anomalies such as tortuous or dilated capillaries, hemorrhages, and avascular areas, which can characterize connective tissue diseases. The utility of NVC in the diagnosis and monitoring of systemic sclerosis (SSc) has been investigated in numerous studies allowing the distinction of the specific microvascular pattern of scleroderma from different conditions other than scleroderma (non-scleroderma pattern). Sarcoidosis (SA) is a systemic inflammatory disease that can affect various organs, including the lungs, skin, and lymph nodes. The purpose of our review was to evaluate the current state of the art in the use of NVC in the diagnosis of SA, to understand the indications for its use and any consequent advantages in the management of the disease in different settings in terms of benefits for patients. MATERIALS AND METHODS: We searched for the key terms "sarcoidosis" and "video-capillaroscopy" in a computerized search of Pub-Med, extending the search back in time without setting limits. We provided a critical overview of the literature, based on a precise evaluation. After our analysis, we examined the six yielded works looking for answers to our questions. RESULTS: Few studies have evaluated that microcirculation is often compromised in SA, with alterations in blood flow and consequent tissue damage. DISCUSSION: Basing on highlighted findings, NVC appears to be a useful tool in the initial evaluation of sarcoidosis patients. Furthermore, capillaroscopy is useful in the evaluation of the coexistence of sarcoidosis and scleroderma spectrum disorder or overlap syndromes. CONCLUSIONS: In conclusions, no specific pattern has been described for sarcoidosis, and further re-search is needed to fully understand the implications of nailfold capillaroscopy find-ings in this disease and to establish standardized guidelines for its use in clinical practice.

Ultrasound nail assessment in patients with psoriasic arthritis: is there an association of findings with clinical scores?

BACKGROUND: Psoriatic arthritis can involve several domains. Due to its multifaceted nature and its frequent comorbidities such as depression, obesity, osteoarthritis and fibromyalgia, it is difficult to monitor these patients because the clinical scores involve subjective data. High-resolution ultrasound probes allowed the evaluation of more superficial structures, such as the nails and their synovio-entheseal framework, in close relationship with the enthesis of the distal extensor digitorum tendon. Nail ultrasound studies vary in terms of the parameters and fingers studied and in their findings. OBJECTIVES: To describe the most significant sonographic nail changes and the most affected fingers in psoriatic arthritis and to verify the association of nail ultrasound findings with clinical scores (nail psoriasis severity index (NAPSI), ankylosing spondylitis disease activity score with C-reactive protein (ASDAS-CRP), minimal disease activity (MDA), disease activity index for psoriatic arthritis (DAPSA)). METHODS: This was a cross-sectional study with 52 patients with psoriatic arthritis at the Hospital de Clínicas do Paraná and 50 controls. A total of 1016 nails were analyzed (517 from patients with psoriatic arthritis and 499 from controls). Ultrasonography of the nails of the 10 fingers was performed to assess the trilaminar appearance, measure the distance from the nail bed, identify synovitis of the distal interphalangeal joints and the presence of a power Doppler signal from the nail matrix/nail bed. The captured images were independently evaluated by a rheumatologist with expertise in musculoskeletal ultrasound. Data analysis was performed using IBM SPSS Statistics v.28.0.0 software, and the association of nail plate changes, nail bed distance and power Doppler signal with the NAPSI, DAPSA, MDA and ASDAS-PCR were calculated. Spearman correlation coefficients were estimated to analyze the correlations between pairs of quantitative variables. Student's t test and the Mann‒Whitney U test were used to compare quantitative variables, and Fisher's exact test was used to compare categorical variables between patients and controls. The nonparametric Mann‒Whitney U and Kruskal‒Wallis tests were used to compare groups according to the MDA or DAPSA classification. RESULTS: The Doppler signal of the nail matrix and nail bed was more frequently identified in patients (44.2%) than in controls (6%), and the difference in the mean power Doppler signal between the two groups was significant (p < 0.001). Changes in the nail plate were more common in the right thumb (44.2%), left thumb (36.5%) and second finger on the right hand (32.7%). The number of fingers with nail plate changes, enthesitis, paratendinitis, grayscale synovitis and DIP involvement in the distal interphalangeal joints was higher among patients with psoriatic arthritis (p < 0.001). There were found some correlations between US findings and clinical scores: ultrasound nail involvement and the NAPSI score (p = 0.034), the number of fingers and mean change in the nail plate and the ASDAS-CRP (p = 0.030). DAPSA (remission/low activity versus moderate/high activity) was associated to the mean change in the nail plate (p < 0.013). CONCLUSIONS: Nail ultrasound has the potential to assist in the capturing of the actual disease activity status in patients with psoriatic arthritis.

Differential diagnosis of pigmented nail lesions.

The diagnosis of pigmented nail lesions is a concern for both general practitioners and dermatologists, due to the possibility of indicating nail melanoma. The origin of the dark pigmentation can be either melanocytic or non-melanocytic (fungi, bacteria, or blood), and clinical evaluation alone may not be sufficient for differentiation, requiring additional exams. Onychoscopy provides valuable information prior to biopsy. The causes of nail pigmentation will be described to aid in the differential diagnosis.

Development of a core domain set for nailfold capillaroscopy reporting.

BACKGROUND: The peripheral microangiopathy may be well evaluated and studied by nailfold capillaroscopy (NFC) which is a safe and non-invasive technique. NFC has been reported to have both diagnostic and prognostic values in patients presenting with Raynaud's phenomenon. OBJECTIVE: The overarching objective of this work was to make a consensus on what domains should be included in a capillaroscopy report and that it can be used in daily clinical practice and clinical research in the area of rheumatology. METHODS: A Delphi questionnaire was developed regarding capillaroscopy report from a literature review and expert consensus. The first Delphi round included 14 core areas, its 18 domains with 50 subdomains, derived from a systematic literature review. The level of evidence was determined for each core set using the Oxford Centre for Evidence-based Medicine (CEBM) system. Nine response categories have been set per each item ranging between 1 and 9. Round 2, aimed to reach preliminary consensus "in" or "out" for domains. It included all items that were rated "critical" by at least 80% of the participants as well as any new domains proposed in round 1. RESULTS: The participants to the first, and second round were 11 experts. Fourteen domains were discussed in the two rounds. At the end of the survey, the final report template of NFC in rheumatology reached a consensus. CONCLUSION: A nailfold capillaroscopy report template has been developed by this study, based on outcomes of a Delphi process, by international participants panel. All domains met the 80% voting threshold set in this work. The reporting template can be used for both clinical research as well as day to day practice to provide guidance and standardize the NFC reporting.

Capillaroscopy in the daily clinic of the pediatric rheumatologist.

In the last decade, nailfold capillaroscopy is finding its way to the daily clinic of (pediatric) rheumatologist. This review will provide the necessary knowledge for the clinician performing this easy and non-invasive examination in children. In the first part, background information on type of capillaroscopy device and standardized (internationally validated) interpretations for the different capillary variables compared to healthy pediatric controls will be provided. The second part focusses on capillary changes that are observed in Raynaud's phenomenon with follow-up recommendations. This part will also cover capillaroscopy findings in juvenile systemic sclerosis, childhood-onset systemic lupus erythematosus, juvenile dermatomyositis and -mixed connective tissue disease, as well as correlations with disease severity. Lastly, a research agenda shows the current gaps we have in knowledge in this niche of nailfold capillaroscopy in pediatric connective tissue diseases.

Relationship between nailfold capillaroscopy findings and the etiology and prognosis of interstitial lung disease.

OBJECTIVES: Connective tissue-associated interstitial lung diseases (CTD-ILD) are believed to be caused by microvascular damage. The objective of this study was to assess the nailfold capillaroscopy (NFC) pattern in patients diagnosed with both CTD-ILD and non-CTD-ILD to identify microvascular changes and determine the relation between capillaroscopic parameters, clinical variables, and disease-related measurements. PATIENTS AND METHODS: This cross-sectional study included 95 patients with interstitial lung disease who applied to our Rheumatology and Chest Clinics between September 2021 and July 2023. The patients were divided into two groups based on their diagnosis: non-CTD-ILD (group 1) and CTD-ILD (group 2). Nailfold capillaroscopy was performed. RESULTS: Ninety-five patients, 49 (51% female, mean age 62.31 ± 11.027 years) in group 1 and 46 (69.6% female, mean age 62.09 ± 10.887 years) in group 2, were included in the study. Abnormal capillary morphologies were both detected in the CTD-ILD group and the non-CTD-ILD groups. In patients with a usual interstitial pneumonia (UIP) pattern on chest computed tomography (CT), tortuosity was higher than in patients with non-specific interstitial pneumonia (NSIP) (P = 0.041), and the proportion of tortuosity increased significantly as the duration of the disease increased (P = 0.016). CONCLUSION: Our study highlights capillaroscopic abnormalities alone may not be sufficient to differentiate CTD-ILD (other than systemic sclerosis) from non-CTD-ILD. The presence of NFC abnormalities in non-CTD-ILD may suggest that fibrotic lung disease could potentially play a role in the deterioration of the microvascular structure or abnormal angiogenesis. Our study demonstrated that a multidisciplinary approach, incorporating clinical, morphological, pathological, and serological evaluations, is necessary for interpreting ILD. Key Points • Capillaroscopic abnormalities can also be seen in non-CTD-ILD. • Capillaroscopy findings do not distinguish the non-Ssc etiology of ILD. • Nailfold capillaroscopy may have the potential to serve as a useful tool in predicting prognosis and monitoring the disease progression in patients with idiopathic pulmonary fibrosis (IPF).

Stitching method for panoramic nail fold images based on capillary contour enhancement.

Nail fold capillaroscopy is an important means of monitoring human health. Panoramic nail fold images improve the efficiency and accuracy of examinations. However, the acquisition of panoramic nail fold images is seldom studied and the problem manifests of few matching feature points when image stitching is used for such images. Therefore, this paper presents a method for panoramic nail fold image stitching based on vascular contour enhancement, which first solves the problem of few matching feature points by pre-processing the image with contrast-constrained adaptive histogram equalization (CLAHE), bilateral filtering (BF), and sharpening algorithms. The panoramic images of the nail fold blood vessels are then successfully stitched using the fast robust feature (SURF), fast library of approximate nearest neighbors (FLANN) and random sample agreement (RANSAC) algorithms. The experimental results show that the panoramic image stitched by this paper's algorithm has a field of view width of 7.43 mm, which improves the efficiency and accuracy of diagnosis.

Automatic evaluation of Nail Psoriasis Severity Index using deep learning algorithm.

Nail psoriasis is a chronic condition characterized by nail dystrophy affecting the nail matrix and bed. The severity of nail psoriasis is commonly assessed using the Nail Psoriasis Severity Index (NAPSI), which evaluates the characteristics and extent of nail involvement. Although the NAPSI is numeric, reproducible, and simple, the assessment process is time-consuming and often challenging to use in real-world clinical settings. To overcome the time-consuming nature of NAPSI assessment, we aimed to develop a deep learning algorithm that can rapidly and reliably evaluate NAPSI, thereby providing numerous clinical and research advantages. We developed a dataset consisting of 7054 single fingernail images cropped from images of the dorsum of the hands of 634 patients with psoriasis. We annotated the eight features of the NAPSI in a single nail using bounding boxes and trained the YOLOv7-based deep learning algorithm using this annotation. The performance of the deep learning algorithm (DLA) was evaluated by comparing the NAPSI estimated using the DLA with the ground truth of the test dataset. The NAPSI evaluated using the DLA differed by 2 points from the ground truth in 98.6% of the images. The accuracy and mean absolute error of the model were 67.6% and 0.449, respectively. The intraclass correlation coefficient was 0.876, indicating good agreement. Our results showed that the DLA can rapidly and accurately evaluate the NAPSI. The rapid and accurate NAPSI assessment by the DLA is not only applicable in clinical settings, but also provides research advantages by enabling rapid NAPSI evaluations of previously collected nail images.

Nailfold capillary measurements correlated to NOTCH3 R544C mutation in preclinical CADASIL patients.

BACKGROUND: Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy (CADASIL) is a hereditary disease caused by NOTCH3 mutation. Nailfold capillaroscopy is a non-invasive technique typically used for rheumatic diseases. It has potential in other conditions linked to vascular pathology. However, capillaroscopy in CADASIL has not been explored. This study aims to investigate whether capillaroscopy measurements can correlate with brain vascular changes in preclinical CADASIL patients, specifically those with NOTCH3 mutation. METHODS: This study included 69 participants from the Taiwan Precision Medicine Initiative (TPMI) dataset who visited Taichung Veterans General Hospital from January to December 2022. All individuals underwent genetic studies, brain imaging and nailfold capillaroscopy. The Mann-Whitney U test was used to compare results of brain imaging between carriers and controls. It was also used to compare measurements in nailfold capillaroscopy within each group. Spearman Rank Correlation Analysis was used to explore the relationship between capillary measurements and brain MRI results. RESULTS: White matter hyperintensities (WMH) expression was positively correlated with capillary dimension and negatively correlated with density. Our results presented that R544C carriers exhibited a diffuse increase in WMH (p < 0.001) and a global reduction in gray matter volume but preserved in specific areas. The white matter lesion scores in all brain regions were higher in the mutation carriers than the controls. (p < 0.001). CONCLUSION: This research highlights the association of nailfold capillaroscopy findings with white matter lesions in preclinical CADASIL patients. Capillaroscopy guides an effective screening strategy in individuals with NOTCH3 mutations.

Long-pulsed nd: YAG laser treatment of nail psoriasis: clinical and ultrasonographic assessment.

Nail psoriasis is a chronic, inflammatory condition which is difficult to treat, linked with greater psoriasis severity, and may be associated with anxiety and significant functional impairment of the quality of life. The 1064 nm Nd: YAG laser was reported to yield satisfactory results in the treatment of nail psoriasis.The aim of the study was to assess the clinical and ultrasonographic efficacy of long-pulsed 1064 nm Nd: YAG laser in the treatment of fingernail psoriasis and compare its effect to control fingernails.This intra-patient randomized controlled trial analyzed 86 fingernails collected from 13 patients suffering from cutaneous and nail psoriasis. The nails were randomized into two groups. Group A was treated with Nd: YAG laser once monthly for three sessions while group B served as control. Assessment took place at baseline, 1 and 3 months after the last treatment session. For scoring, the 32-points target NAPSI scoring systems was used. Additionally, two blinded dermatologists' score of improvement, patients' pain assessment by visual analogue score and ultrasonographic assessment were all performed.At the end of follow up, the medians of tNAPSI score, plate definition, matrix thickness, bed thickness and bed vascularity decreased significantly in the Nd: YAG laser treated group in comparison to baseline (p = 0.001, 0.006, 0.039, < 0.001 and 0.010, respectively). While, there was a non-significant reduction in median tNAPSI score in the control group at last follow up, however, ultrasonography recorded a significant reduction in the medians of plate definition, bed thickness and vascularity (p = 0.002, 0.011 and 0.033, respectively) from the baseline. Comparison of the Nd: YAG laser and the control groups showed no significant difference from baseline regarding the medians of tNAPSI, tNAPSI percentile improvement, pits count, blinded evaluation of photographs and ultrasonographic assessments.In conclusion, Nd: YAG laser showed clinical and ultrasonographic improvement in fingernail psoriasis. Ultrasonography is a useful noninvasive tool in diagnosing and monitoring the clinical and even the subclinical changes in nail psoriasis. Nail psoriasis although difficult to treat, may show spontaneous improvement.

Ultrasonographic evaluation of nail matrix topography for preservative nail surgery of nail unit melanoma.

Recently, functional or preservative surgery has been preferred for nail unit melanoma; however, complete resection of the nail unit, particularly the matrix, is challenging because of its complex structure. This study aims to measure the distance of important nail structures through ultrasonography. Herein, 14 patients without nail deformity were included. The length from the nail cuticle to the distal interphalangeal joint (distance X), to the attachment part of the extensor muscle (distance A), to the median proximal end of the nail matrix (distance B), and to the lateral proximal end of the nail matrix (distance C) were measured. In the axial plane, the length from the highest point of the nail plate to the bottom of the distal phalanx (distance Y) and to the lateral tip of the nail plate (distance D) were measured. On the first fingernail, third fingernail, first toenail, and third toenail, the mean ratio A:X, ratio B:X, ratio C:X, and ratio D:Y were 78.6%, 44.3%, 57.2%, 40.1%, and 84.6%; 55.9%, 64.9%, 40.2%, and 66.4%; 35.6%, 50.8%, 34.3%, and 81.9%; and 57.2%, 59.6%, and 31.7%, respectively. Nail units are often invisible to the naked eye; thus, this study will help identify the approximate scope of excision.

Description of the characteristics of the nailfold capillary structure in healthy children: a multi-centric study.

BACKGROUND: Nailfold videocapillaroscopy (NVC) is the primary diagnostic tool for the assessment of microcirculation in the pediatric population. OBJECTIVE: To define and standardize age-specific normal NVC patterns in healthy children and adolescents. METHODS: A cross-sectional observational multicentric study was conducted in 564 participants aged 5-17 years. Dino-Lite CapillaryScope 200 Pro Model MEDL4N Pro was performed at 200× magnification. Quantitative and qualitative NVC parameters were analysed separately for each age group and divided into four groups based on age categories. RESULTS: Of the 564 healthy participants, 54.9% were female. A total of 1184 images and 3384 capillaries were analysed. Positive correlations were observed between age and capillary density (P < 0.001, R = 0.450, CI95% 0.398-0.503). There was also a positive correlation between age and arterial/venous, loop diameter and capillary length, whereas there was a weak negative correlation between intercapillary distance. However, no correlation was found between age and capillary width. In addition, capillary density was significantly lower in the 5-7 age group compared with the other patient groups. Arterial limb diameter was lower in the 5-7 age group, while venous limb diameter was significantly wider in the 15-17 age group compared with the other patient groups. Dilated capillaries (8.7%), capillary tortuosity (14.4%), crossed capillaries (43.1%), micro-haemorrhages (2.7%) and avascular area (4.8%) were present in all age groups. Excellent intra- and interobserver ICC values were obtained for all parameters. CONCLUSION: These findings hold potential significance for future studies, aiding in the analysis and differentiation of children suspected of rheumatological diseases with potential microangiopathy.

Intra-operative dermoscopy (onychoscopy) of the nail unit-A systematic review.

Dermoscopy of the nail unit (onychoscopy) is a method which allows for non-invasive observation of the nail structures, increasing the accuracy of clinical diagnosis. Currently, it is used in evaluation of both inflammatory and neoplastic conditions of the nail unit. However, in contrast to the skin, the anatomy of the nail unit prevents direct observation of nail bed or nail matrix structure during classic onychoscopy. Intra-operative onychoscopy is a variant of the technique which uses direct visualization of the nail unit structures after nail plate avulsion. The aim of this systematic review was to summarize the current state of knowledge on intra-operative onychoscopy. The MEDLINE, EMBASE and Cochrane databases were systematically searched in January 2024. All types of study designs assessing intra-operative dermoscopy of the nail unit were included in this study. The risk of bias in included studies was assessed using the Joanna Briggs Institute critical appraisal tools. The qualitative synthesis of 19 studies totalling a number of 218 cases in 217 patients included the following entities: melanoma, nevus, hypermelanosis (melanocytic activation), melanocytic hyperplasia, melanophages accumulation, squamous cell carcinoma, glomus tumour, lichen planus, onychomatricoma, onychomycosis and subungual exostosis. The main limitation of the study was a relatively low number of identified studies, most with low levels of evidence. Intra-operative onychoscopy does not replace histologic examination, though it may be useful in determining the modality of surgical diagnostic procedures.

Ultrasonographic and power doppler parameters of nails fail to differentiate between onychodystrophy in patients with psoriasis vulgaris or psoriatic arthritis.

BACKGROUND: Nail involvement is frequent in patients with psoriasis (Pso) and psoriatic arthritis (PsA) and there is a relationship between nail involvement and inflammation of the enthesis. The main objective of the present study is to describe the ultrasound findings and clinical characteristics of nails from patients with psoriasis and psoriatic arthritis with and without nail dystrophy. METHODS: A cross-sectional study including consecutive patients with PsO and PsA was carried out. The study patients were divided into 4 groups, totaling 120 participants. Group 1: patients with psoriasis vulgaris and clinically normal nails; Group 2: patients with psoriasis vulgaris and onychodystrophy; Group 3: patients with psoriatic arthritis and clinically normal nails; Group 4: patients with psoriatic arthritis and onychodystrophy; All patients were submitted to dermatological and rheumatological clinical analysis. Ultrasound examinations was performed by a single examiner, blinded to all clinical data, with ultrasound high resolution, in B-mode or gray-scale (GS), Power Doppler (PD) and Spectral Doppler. RESULTS: A significant difference was found between the groups regarding the variable Psoriasis Area and Severity Index (PASI) (p = 0.008) and body surface area (BSA) (p = 0.005), with patients with psoriatic arthritis having lower PASI and BSA compared to patients with only cutaneous psoriasis. A positive relationship was found with the average ultrasound thickness of the nail bed and the Nail Psoriasis Severity Index (NAPSI) in correlation analysis (rho = 0.344). When we grouped patients with psoriasis and psoriatic arthritis, there was no significant difference between the cutaneous psoriasis groups and the psoriatic arthritis groups in terms of nail plate GS (p = 0.442), nail bed PD (p = 0.124). CONCLUSION: Greater nail bed thickness indicates early psoriatic nail disease, as confirmed in our study correlating NAPSI with nail bed thickness. Ultrasonography is a low-cost exam, promising in the evaluation, showing that the ultrasound grayscale is consistent with those who have dystrophic nails, but it can't distinguish psoriasis from psoriatic arthritis, even in those with nail dystrophy.