Applications of High-Resolution Ultrasound in Dermatology

Original Article: Seeing beyond skin deep: High-resolution ultrasound in

dermatology—A comprehensive review and future prospects

What are the key takeaways of this article?

High-Resolution Ultrasound (HRUS) is a non-invasive imaging technique that utilizes high-frequency sound waves to produce detailed images of structures beneath the skin. In 2024, Liu et al. conducted a comprehensive literature review on the dermatological application of HRUS and its adjunctive role in diagnosis and management.

Liu et al. found several applications of HRUS in clinical dermatology.

1. In skin exams, HRUS can identify and quantify age-related changes and photodamage in normal skin.

2. In the assessment of skin cancer, HRUS presents a less invasive adjunct to making a diagnosis compared to biopsies which may leave scars or alter the target tissue. In melanomas, HRUS can be used to accurately predict Breslow thickness. The imaging technique can also aid pre-operative tumour assessment, supporting the decision between non-surgical interventions, Mohs micrographic surgery, or wide local excision.

3. HRUS has shown potential to differentiate lesion tomography between actinic keratosis, Bowen's disease, SCC and high-risk BCC.

4. In inflammatory skin conditions, HRUS can be used to assess and monitor diseases such as psoriasis and hidradenitis suppurativa, providing insights into disease progression and therapeutic efficacy.

5. In cosmetic dermatology, HRUS can be utilized to produce real-time visualization of critical structures and tissue planes, thereby improving the safety of injection procedures on the face.

Compared to other diagnostic methods, HRUS offers several advantages. It is safe, portable, quick, and less invasive for the patient. It provides real-time visualization of structures below the skin, allowing for dynamic assessment during clinical examinations and improving the safety of procedures near critical anatomical structures. The real-time visualization has an advantage for tumour characterization over biopsied specimens, where it enables “in-the-moment” clinical decision-making. The high-frequency transducers (20-25 MHz) in HRUS allow for the production of high-resolution images of the epidermis and dermis, which supports detailed assessment of the superficial structures. HRUS devices that include Doppler ultrasound would also allow the characterization of vasculature and assessment of blood flow, which could be beneficial in patients with inflammatory skin conditions or malignancies.

Nevertheless, HRUS also presents known limitations. It has unknown accuracy in measuring total tumour size; HRUS estimation of BCC sizes might be 29% over clinical estimates. Ultrasound assessment of SCCs might also be challenging due to the acoustic shadow artifact that obscures the boundaries of the lesion. HRUS alone also cannot reliably differentiate between melanoma and benign melanocytic naevi; the addition of Doppler ultrasound would be needed to visualize the commonly denser vascularization in melanoma.

To conclude, HRUS is a promising tool that can aid real-time lesion visualization, early detection, pre-operative planning, and easy monitoring of disease progression. Although not yet widely used in clinical dermatology, Liu et al. call for clinician awareness of its benefits and applications, and the upskilling of dermatologists in sonography techniques that could significantly enhance their practice.

Publication Date: February 11, 2025

Reference: Liu, Zhao Feng et al. “Seeing beyond Skin Deep: High‐resolution Ultrasound in Dermatology—A Comprehensive Review and Future Prospects.” Journal of the European Academy of Dermatology and Venereology 38.7 (2024): 1305–1313. Web.

Summary By: Zili Zhou