Psoriasis (PsO) is a common chronic relapsing inflammatory disease, induced by a combination of genetic and environmental effects, which seriously affects the quality of life of patients.Psoriasis Area and Severity Index（PASI score ） ，as the most common method used by clinicians to assess the severity of psoriasis and the effectiveness of treatment, has the disadvantage of being subjective and superficial.We are therefore committed to establishing an objective, real-time, repeatable, non-invasive, microscopic assessment using high-frequency ultrasound. This study will use high-frequency ultrasound to detect the patient's lesion site and the 2cm site next to the lesion once, and the study will continue to recruit for 6 months.

High-frequency ultrasound (HFUS) with a center frequency of more than 10 MHz, and a resolution of 16-158 μm. The detailed detection items are epidermal thickness (unit mm), dermal thickness (unit mm), hypoechoic cord thickness between epidermis and dermis (unit mm), epidermal echo intensity, dermal echo intensity, clarity of the boundary between dermis and subcutaneous tissue detected by Grayscale ultrasound; blood flow signal (pcs) detected by Color Doppler imaging and Power doppler imaging. The 8 tests will be detected the skin lesions and 2cm beside skin lesions area.Based on the correlation between the 8 indexes and local PASI scores, we will establish a model for the evaluation of psoriasis by multimodal high-frequency ultrasound.This study will use high-frequency ultrasound to detect the patient's lesion site and the 2cm site next to the lesion once, and the study will continue to recruit for 6 months

Inclusion Criteria:

1. Patients who meet the medical criteria for plaque psoriasis
2. Those who voluntarily participate in this study and sign the informed consent form

Exclusion Criteria:

1. Patients with other types of psoriasis
2. Those with other active medical conditions that may affect assessment
3. During a severe uncontrollable acute or chronic local or systemic infection
4. Those with severe mental illness, cognitive impairment, and incapacity for personal behavior that makes them unsuitable to participate in a clinical study
5. Other reasons the investigator considers unsuitable for participation in this study

Patients aged 18-75 years with plaque psoriasis who meet inclusion and exclusion criteria