Diagnostic value of 20 MHz high-frequency ultrasound for skin scars

Abstract

Objective To observe and summarize the differences in ultrasonic characteristics, scar thickness and echo intensity for different types of scar skins by using 20 MHz high-frequency ultrasound. Methods A total of 48 patients with scars admitted to our hospital from 2018 to 2019 were recruited in this study, and were divided into hypertrophic scar group (n=20), keloid scar group (n=18) and atrophic scar group (n=10) according to scar categories. Another 20 volunteers with normal skin living in Luzhou urban area served as normal control group. Ultrasound images of scar skin or normal skin of volunteers were collected by 20 MHz high-frequency ultrasound. Skin thickness was measured by distance measuring tool of this software. At the same time, echo density was analyzed by DFY-Ⅰ ultrasound image quantitative analysis. Results In terms of the structure of skin tissue, compared with normal skin, hypertrophic scar and keloid had uneven epidermis and upward protuberance, and clear boundary between dermis and subcutaneous tissues. Atrophic scar skin had a thin epidermis and the unclear boundary between dermis and subcutaneous tissue. In terms of overall skin thickness, the skin thickness of hypertrophic scar (P < 0.001) and keloid(P=0.001) was significantly thicker than that of atrophic scar and normal skin, while there was no significant difference between atrophic scar and normal skin. In terms of echo density, the echo density of hypertrophic scar(P=0.001) and keloid(P < 0.001) dermis was significantly lower than that of normal skin. Hypertrophic scars appeared as striated hypoechoic areas in the upper dermis, while keloids as oval hypoechoic areas concentrated under the epidermis.There was no significant difference in overall echo density between atrophic scar and normal dermis. Conclusion The 20 MHz high-frequency ultrasound shows the characteristic ultrasonic manifestations of different types of scar.The dermis of keloid has a concentrated oval hypoechoic region, while the dermis of hypertrophic scar has a low gyrus.However, the boundary of each skin in atrophic scar sublayer is unclear, which the dermal echo intensity is uneven.

Keywords

• sacr
• high-frequency ultrasound
• skin sonogram
• skin thickness
• echo-density of skin