The role of testicular ultrasound examination is as follows: 1. observe the size of testicles: whether there is any change in the size of testicles, if some testicles are small, it suggests testicular atrophy; 2. observe the presence or absence of testicles: see whether there are testicles inside the scrotum, and also pay attention to observe whether there is cryptorchidism in the groin area; 3. observe testicular contents: when testicular echogenicity is generally reduced and blood supply disappears, testicular torsion is suspected; when testicular enlargement and blood supply increase, testicular atrophy is suspected; when hypoechoic nodules are found, testicular tumor is suspected.