Diameter-dependent classification of dermal vasculature using optical coherence tomography angiography

• Published in: Quantitative imaging in medicine and surgery 2024-09, Vol.14 (9), p.6238-6249
• Main Authors: Hoshino, Takuma, Cheng, Yuxuan, Ninomiya, Masato, Katsuyama, Masako, Yamashita, Toyonobu, Katagiri, Chika, Wang, Ruikang K, Hara, Yusuke
• Format: Article
• Language: English
• Subjects: Original
• ISSN: 2223-4292; 2223-4306
• DOI: 10.21037/qims-23-1790

Dermal blood vessels beneath the epidermis play critical roles in epidermal homeostasis and are functionally divided into several types, such as capillaries. Optical coherence tomography angiography (OCTA) is a powerful tool for the non-invasive assessment of dermal vasculature. However, the classification of vessel types has been limited. To address this issue, we proposed an algorithm for diameter-dependent classification that preserves three-dimensional (3D) information using OCTA. OCTA data were acquired by a prototype swept-source-type optical coherence tomography (OCT) system, which was processed through several imaging filters: an optical microangiography (OMAG) imaging filter, a vesselness imaging filter, and a diameter map filter. All vessels were visually classified into three types based on their diameters, as micro-vessels, intermediate vessels, and thick vessels. Aging-related alterations and their association with the epidermis were investigated for each vessel type. The measurements were conducted on the cheeks of 124 female subjects aged 20-79 years. The 3D vascular structure was visualized by applying our proposed post-processing filters. Based on visual assessment, the thresholds for the diameters of the micro, intermediate and thick vessels were set at 80 and 160 µm. It was found that micro-vessels were predominantly located in the upper layer of the dermis and thick vessels in the deeper layer. Analysis of vessel metrics revealed that the volume density of the micro-vessels decreased significantly with age (r=-0.36, P