Quantification of skin lesions using high-frequency ultrasound and shear wave elastography in port-wine stain...

This study aimed to assess the different types of port-wine stain (PWS) skin lesions quantitatively using high-frequency ultrasound (US) and shear wave elastography (SWE) before and after treatment, and investigate the feasibility and application value of high-frequency US and SWE in PWSs.

A total of 195 PWS patients with 238 skin lesions before treatment and 72 follow-up PWS patients with 90 skin lesions were assessed using high-frequency US and SWE. The skin lesions were divided into four groups: pink-type, purple-type, thickened-type, and nodular-type PWSs. Gray-scale US was used to observe normal skin, observe the skin changes of lesions, and assess the skin thickness. The thickened skin was calculated. Power Doppler (PD) signal grades were used to assess the skin blood signals. SW velocity (in m/s) and Young's elastic modulus (in kPa) were used to assess the stiffness of normal skin and skin lesions. The heightened SWE was also calculated.

The dermis hypoechogenicity, thickness of thickened skin, and skin PD signal grades were significantly higher in all PWS-type groups compared with the normal-skin group (all P<0.05). The thickened skin and skin PD signal grades in the nodular-type and thickened-type group were significantly thicker and higher than those in the pink-type and purple-type group (all P<0.05). The PD signal grades in the purple-type was significantly higher than that in the pink-type group (P<0.05). All SWE values of PWS lesions were significantly higher in the transverse section than those in the longitudinal section (all P<0.05). The differences in heightened E_mean, E_min, C_mean, and C_min between each PWS group and the normal-skin group were not significant. The heightened E_max and C_max in the nodular-type PWS group was significantly higher than those in the normal-skin group and pink-type, and purple-type PWS groups (all P<0.05). The heightened E_max and C_max were significantly higher in the thickened-type PWS group than those in the normal-skin group (all P<0.05). In the evaluation of therapeutic effects, the ratio of dermis hypoechogenicity in pink-type lesions significantly decreased, and thickened skins in all groups were significantly thinned (all P<0.05). The differences of PD signal grades, heightened E_max, and C_max in all groups between pre-treatment and post-treatment showed no significance.

High-frequency US and SWE show feasibility and application values assessing PWS skin lesions. Their features include dermis hypoechogenicity, thicker skin, higher PD signal grades, higher E_max, and higher C_max. Thicker skin is thus the best feature for assessing therapeutic effect.