Whirlpool Sign: Sonographic color Doppler sign of a spiraling vascular pedicle; pathognomonic for testicular or ovarian torsion when visualized.
The whirlpool sign is a sonographic finding on color Doppler ultrasound in which the spermatic cord or ovarian pedicle appears as a rotating or spiraling vascular structure, resembling a whirlpool. It is pathognomonic for testicular torsion and ovarian torsion. The sign represents the twisted cord visualized in cross-section and, when present, confirms the diagnosis with near-perfect specificity.