Ultra‐high frequency ultrasound detection of the dermo‐epidermal junction: Its potential role in dermatology

Abstract

Traditional high‐frequency ultrasound (HFUS; 20 MHz) is a non‐invasive method used to study skin in vivo but is not able to measure skin thickness accurately and to identify the dermal‐epidermal junction (DEJ). Ultra‐high frequency ultrasound (UHFUS; 70–100 MHz) has sub‐millimetre resolution comparable to histology. The aim of this study was to identify, by UHFUS, the DEJ and to describe skin differences in healthy individuals by providing a measure of skin thickness, based on age and gender. We also described the bullous pemphigoid lesion. We enrolled 42 patients divided into 2 groups: A and B. Group A included 32 healthy volunteers aged 22–74 years. Group B consisted of 10 patients with bullous pemphigoid. For each patient in group A, 8 ultrasound (US) clips by 70 MHz probe were performed at forehead, cheek, nose, forearm, abdomen, chest, back and leg. For each patient in group B, 5 US images were acquired at blisters roofs and edges. In each US image, we measured thickness of stratum corneum (α‐β), epidermis (α‐γ) and epidermis plus dermis (α‐δ). In both groups, we found the presence of 4 lines delimiting: the stratum corneum (the layer between α‐line and β‐line), the epidermis (distance between α‐ and γ‐line), and the boundary between dermis and subcutis (δ‐line). The γ‐line corresponds to the point of detachment of the bullae. The abdominal α‐β layer was thicker in males (p = 0.019) and α‐δ thickness at cheeks (p < 0.001), chest (p = 0.007), back (p = 0.025) and forearm (p < 0.001). In females, α‐γ thickness of the back was greater (p = 0.005). In old people compared to young, we noticed an increase of α‐β layer at forehead and chest (p = 0.014), an increase of α‐γ layer at forearm (p = 0.001), back (p = 0.024) and leg (p = 0.010) and an increase of α‐δ layer at forehead (p = 0.001) and nose (p = 0.049). UHFUS is an advanced imaging technique that can detect both the DEJ and the boundary between dermis and subcutaneous tissue so that epidermal and dermal thickness can be measured with good accuracy. Regarding gender and age, skin differences obtained with UHFUS were comparable to other non‐invasive methods.

Ultra‐High Frequency Ultrasound in Melanoma Management

“…Recently, Granieri et al for the first time identified the dermo‐epidermal junction with UHFUS (70 MHz) 37 . This finding can be useful to improve ultrasonographic pre‐surgical assessment of melanoma in the future.…”

“…Moreover, in case of diagnostic incisional biopsy (eg, large lentigo maligna/ lentigo maligna melanoma on the face), UHFUS can guide the clinicians indicating the point of maximum depth. 37 This finding can be useful to improve ultrasonographic pre-surgical assessment of melanoma in the future.…”

Assessment and Monitoring of Nail Psoriasis with Ultra-High Frequency Ultrasound: Preliminary Results

“…The fingernail examination was performed in a seated position with hands placed on a table. The proper distance of the probe from the skin, to permit imaging of superficial structures, was maintained with an appropriate amount of gel [ 23 ]. The fingernail apparatus was assessed in B-MODE with a longitudinal section on the middle point of the lamina.…”

“…The patients were naive to previous conventional and biologic systemic therapies and were evaluated at baseline and after 1 month and after 3 months from the beginning of biologic therapy. At each visit, the clinical investigation was performed by a dermatologist expert in psoriasis who collected a photographic record of the patient and assessed clinical disease parameters such as the psoriasis area severity index (PASI), NAPSI, modified (m)-NAPSI calculated on Diagnostics 2023, 13, 2716 3 of 11 the nail with major clinical alterations and dermatology life quality index (DLQI) [21][22][23]. For the US examination of the nail apparatus, a UHFUS with a 70 MHz probe was used (Vevo MD ®® FUJIFILM VisualSonics, Toronto, ON, Canada).…”

The Role of Ultra-High-Frequency Ultrasound in Pyoderma Gangrenosum: New Insights in Pathophysiology and Diagnosis

“…UHFUS provides clinicians and researchers with a powerful tool to delve deep into the skin's microanatomy, revealing intricate details that were previously inaccessible without invasive procedures. The technique captures comprehensive images of various skin components, such as the dermo-epidermal junction, hair follicles, pilo-erector muscles, and blood vessels [15][16][17][18][19][20][21]. The distinct patterns observed through UHFUS imaging could assist in the early detection of PG, enabling timely intervention and management.…”