Hypoechoic in ultrasound examination is mainly when the ultrasound medium is relatively homogeneous, the acoustic impedance is relatively small, and only a few reflective interfaces are present in a hypoechoic state at normal sensitivity, for example, the normal renal parenchymal echo is hypoechoic, as well as in the liver, spleen and some pathological tissues with glassy degeneration. In contrast, hyperechoic is tissue and organ fibrosis, steatosis, etc., which may manifest as diffuse punctate hyperechoia. When there is neoplastic formation within the organ, it may manifest as hyperechoic nodules or masses, resulting in enhanced echogenicity due to the tighter structure of the pathological tissue compared to normal tissue, increased acoustic impedance, and increased reflective interfaces.