Quantitative assessment of treatment efficacy in keloids using high-frequency ultrasound and shear wave elastography: a preliminary study

The purpose of this study was to investigate the performance of high-frequency ultrasound (HFUS) and shear wave elastography (SWE) in the quantitative evaluation of therapeutic responses of keloids. 43 patients with 76 keloids were recruited into this study. In keloids and symmetrical sites, the skin thickness was measured using HFUS and skin stiffness expressed as elastic moduli (Young's modulus and shear wave velocity) was measured using SWE. The coefficient of variation values were calculated by using difference values of skin elastic moduli and skin thickness. A significant increase of both skin stiffness and thickness appeared in pre-treated keloids compared with post-treated keloids (P < 0.001) and normal controls (P < 0.001), respectively. Stiffness in post-treated keloids and normal skins was significantly different (P < 0.001), while the difference in thickness measurements showed no significance (P = 0.56, >0.05). The coefficient of variation ofYoung's modulus was the highest when compared between (i) pre-treated keloids and theirs site-matched areas; (ii) pre-treated and posttreated keloids. SWE, which showed greater ability in determining the extent of keloids recovery, may provide an ideal tool to assess the stiffness of keloids and theirs therapeutic response.