varicocele

Longitudinal sonogram through the left testicle. This image shows several large anechoic tubes (2.4-6 mm in diameter) lying behind the upper and middle poles of the testicle. The diameter of these tubes increased by 1.5-2 mm with a Valsalva maneuver (not shown). T = testicle; v = varicocele.


http://emedicine.medscape.com/article/382288-overview