Ultrasound examination. An ultrasound machine used to locate adult worms in the scrotum of a man with schistosomiasis. In ultrasound scanning high frequency sound waves are passed into the body, & the reflected echoes are analysed to produce an image of internal tissues. Schistosomiasis is a chronic trematode worm infection picked up from fresh water containing worm larvae. It is common in tropical countries. The worms mature in the veins of the intestines & bladder, producing large numbers of eggs which provoke inflammation and fibrosis that obstructs urine flow in the ureters or blood flow in the liver. Treatment is with the drug praziquantel.