Testicular blood flow is visualized on the normal side but is absent on the affected side (left) and the spermatic cord displays the whirlpool sign. The diagnosis of testicular torsion was confirmed with surgery.
(a) normal right longitudinal US scan (left image) obtained at the level of the external inguinal ring
(b) left longitudinal US scan (middle image) obtained at the level of the external inguinal ring shows an abrupt change in the configuration of the spermatic cord (arrow), with whirlpool sign
(c) color Doppler of both testes in transverse view (right image) shows normal vascularization on the right. The left testis is increased in size, mildly heterogeneous in echotexture and without central vascularization.