High-Frequency Ultrasonography Evaluation of Acne by Thickness and Power Doppler Vascular Analysis.

HF-USG and PD equipped with semi-quantitative analysis software can assess acne vulgaris quantitatively, which provides a good basis for the classification and treatment of acne. Their features include thickness ratio, Qpack ratio, and Qpack peak, with Qpack ratio and Qpack peak being the sensitive features for the early efficacy evaluation.