Hi and thanks for the post

Ultrasound works by sound waves passing between tissues- they travel into the area being looked at and will pick up an abnormality  in the testes. Ultrasound is the routine test used to look at the testes and to examine them for any lumps.

I should think that if there had been a lump, the ultrasound would have picked this up. You can always ask the clinic or family doctor if you continue to have concerns.

All the best

Wanda