Optical Coherence Tomography in the Evaluation of the Scalp and Hair: Common Features and Clinical Utility

Abstract

Background and Objective Early diagnosis and treatment of hair loss disorders is vital in providing patients with improved psychological outcomes. Non‐invasive imaging with optical coherence tomography (OCT) may be useful in characterizing and managing alopecia. Despite expanding clinical applications of OCT in dermatology, guidelines demonstrating in vivo features of normal and alopecic scalp images remain scant. This pilot study aims to provide an atlas of OCT findings of healthy and alopecia subjects, explore diagnostic quantitative endpoints of alopecia, and compare epidermal thickness and follicular density between scalp regions. Study Design/Materials and Methods A total of 32 patients (19–76 years old) were enrolled in the study, including healthy patients (n = 6), and patients with scarring alopecia (n = 12) or non‐scarring alopecia (n = 14). An in‐line fiber‐based swept source OCT was used to image five scalp locations at baseline and 6‐month visits. Three investigators evaluated each image for gross features, epidermal thickness, and follicular density. Results Only data from baseline imaging analysis is discussed in this manuscript. Qualitative differences of OCT images are identified in sample images from healthy scalp and each subtype of alopecia studied. Scarring alopecia is characterized by significantly increased epidermal thickness (average Image J pixel units 32 ± 2 compared with non‐scarring alopecia [average 28 ± 3] and control [average 27 ± 3]) (P = 0.022) and decreased follicle count (average 35 ± 5 in a 5 × 7 mm2 area compared with control (50 ± 3) and non‐scarring patients (47 ± 6)) (P = 0.0052). Scalp location had no impact on epidermal thickness (P = 0.861) or follicular density (P = 0.15). Conclusion OCT holds promise as a non‐invasive technique to further characterize and objectively measure alopecia. Larger sample sizes and longitudinal data are needed to improve reliability and determine if additional distinction between alopecia subtypes and treatment monitoring is possible. Lasers Surg. Med. © 2020 Wiley Periodicals, Inc.

Recent Advances in Understanding of the Etiopathogenesis, Diagnosis, and Management of Hair Loss Diseases

“…This technique has a hidden potential to replace scalp biopsy by depicting clinically meaningful histological findings, such as the pattern and severity of inflammation and fibrosis, ratio of telogen/anagen hairs, and subcutaneous abnormalities [12]. Other emerging imaging techniques include optical coherence tomography [13,53,54], phototrichogram [55], videodermoscopy [56], and reflectance confocal microscopy [57,58], which have been reported to provide non-invasive and supportive diagnostic tools for hair and scalp diseases.…”

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“…It also provides functionality in addition to structural information, allowing for the assessment of changes in the vasculature network in the skin. On the basis of these abilities, OCT has shown potential for the noninvasive diagnosis and delineation of nonmelanoma skin cancer (Sinx et al, 2020), the evaluation of alopecia (Ekelem et al, 2021), and noninvasive diagnosis and delineation of skin diseases related to dynamic changes in the vasculature (Olsen et al, 2018). RCM has a superior spatial resolution to OCT, and therefore it has been evaluated and proved an efficient imaging approach in dermatology for a broader range of applications such as noninvasive diagnosis of melanoma (Pezzini et al, 2020; Yélamos et al, 2017), nonmelanoma skin cancer (Que, 2016), and other skin conditions (Levine and Markowitz, 2018); monitoring of skin therapy (Malvehy et al, 2016); or evaluation of human skin microcirculation (Saknite et al, 2020).…”

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