High-frequency quantitative ultrasound in characterizing human skin aging: an exploration of the non-modeling and modeling approaches.

BACKGROUND

High-frequency quantitative ultrasound (HQUS) technology, with its non-invasiveness, high-resolution, objectivity, and reproducibility, holds significant potential for characterizing skin aging through the analysis of the internal structure of tissues. This study aims to explore a framework for characterizing skin aging assessment through HQUS technology to facilitate the subsequent analysis of skin aging-related studies.

METHODS

In this study, an exploration of non-modeling and modeling HQUS techniques in characterizing skin aging was conducted. In particular, we tested the conventional approach using the envelope amplitude, the non-modeling approach based on the small-window entropy and the modeling approach with the Nakagami parameters ( and ) at scanning depths of 1 and 1.5 mm, respectively, and discovered that such a characterization framework is well-suitable for quantifying skin aging. These parameters were calculated based on ultrasound backscattered signals at a high frequency of 42 MHz from the facial skin (from the epidermis to the dermis) of 70 female participants aged 24-57 years and then analyzed using the linear fitting and receiver operating characteristic (ROC) curves.

RESULTS

The results show that there exists a linear correlation between all parameters and participant ages at scanning depths of 1 and 1.5 mm, respectively. Among them, the correlation coefficients for parameter are r=0.84 (P<0.0001) and r=0.65 (P<0.0001), which are higher than those for the relative envelope amplitude, small-window entropy, and parameter . Moreover, the parameter also has the highest area under the curve among the ROC curves, regardless of the scanning depth.

CONCLUSIONS

This characterization framework, especially the modeling of the Nakagami parameter , has great feasibility for the characterization of human skin aging. The proposed framework holds significant potential for assessing the efficacy of facial rejuvenation products, photofacials, and similar treatments.