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Artificial intelligence (AI) and capillaroscopy: new horizons
Vol. 33 No. 3 (2026), Review articles
Vol. 33 No. 3 (2026)

Artificial intelligence (AI) and capillaroscopy: new horizons

Review articles
https://doi.org/10.35465/rbj.rbj.406
Published January 27, 2026
Jaklin Doncheva-Dilova
UMНAТ „Sv. Iv. Rilski“, Department of Occupational Diseases, Medical University – Sofia
Nikolay Stoilov
UMНAТ „Sv. Iv. Rilski“, Medical University – Sofia
Vladimira Boyadzhieva
UMНAТ „Sv. Iv. Rilski“, Medical University – Sofia
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Keywords

Artificial Intelligence
machine learning
capillaroscopy

How to Cite

Doncheva-Dilova, J., Stoilov, N., & Boyadzhieva, V. (2026). Artificial intelligence (AI) and capillaroscopy: new horizons. Rheumatology (Bulgaria), 33(3), 11-23. https://doi.org/10.35465/rbj.rbj.406
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Abstract

Nailfold capillaroscopy (NFC) is a well-established, highly specialized, non-invasive method for assessing microcirculation and represents the “gold standard” in rheumatology for distinguishing primary from secondary Raynaud’s phenomenon (RP). Through analysis of capillary structures in the nailfold region, clinicians can identify diff erent patterns (scleroderma, scleroderma-like, and non-specifi c). Despite its clinical signifi cance, image interpretation remains challenging due to subjectivity and the requirement for substantial examiner expertise. In recent years, artifi cial intelligence (AI) has off ered novel solutions through the automated recognition and analysis of capillary structures. Machine learning and deep learning approaches have demonstrated high eff ectiveness in detecting abnormalities, classifying capillary patterns, and predicting the risk of systemic sclerosis. Projects such as CAPI-Detect, along with various other machine learning, deep learning, and neural network models (DenseNet-121, Effi cientNet-B0, ResNet-34, NFC-Net), have shown that AI can identify novel quantitative parameters not accessible through traditional visual assessment and can increase the objectivity and reproducibility of results up to 90%. Most studies in this fi eld focus on capillaroscopic patterns in systemic sclerosis (SSc); however, pilot studies in juvenile dermatomyositis, diabetes mellitus, and hypertension further highlight the applicability of these technologies. Some AI models are even capable of distinguishing onychomycosis, nail psoriasis, and subungual melanoma. Machine learning and deep learning models based on image analysis (Vision Transformer, ViT) appear to represent an additional valid system for the early and rapid interpretation of NFC images and morphological biomarkers in systemic sclerosis (SSc), integrating EULAR-validated algorithms for distinguishing scleroderma from non-scleroderma patterns with artifi cial intelligence (AI). Beyond its diagnostic applications, AI also holds potential in disease monitoring, assessment of therapeutic response, and the development of personalized treatment strategies. The processing of digital images through validated machine learning algorithms, neural networks, and related approaches is aligned with the priorities of the National Health Strategy 2030 for digitalization and the development of eHealth (Policy 2.5). The establishment of a National Digital Platform for Medical Diagnostics is envisaged, aimed at supporting all medical specialties. This platform will be integrated with the National Health Information System and the electronic patient record, with the primary objective of improving the quality of healthcare services. The integration of AI into medical practice opens new opportunities to support early diagnosis and improved management of patients with microangiopathy, facilitating timely detection and the prevention of complications, with the ultimate aim of ensuring better quality of life and preserved functional capacity.

https://doi.org/10.35465/rbj.rbj.406
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