Which Doppler ultrasound finding supports a diagnosis of testicular torsion in a stable patient?

• A. Increased blood flow to the testis
• B. Normal blood flow with edema
• C. Decreased or absent blood flow to the testis
• D. Testicular enlargement with hydrocele

Answer: (C)

Doppler ultrasound assesses blood flow to the testis. In testicular torsion, twisting of the spermatic cord obstructs arterial inflow, leading to reduced perfusion and ischemia. On color Doppler, this most reliably appears as decreased or absent arterial signal in the affected testis, even in a patient who is hemodynamically stable. This finding helps distinguish torsion from inflammatory conditions like epididymo-orchitis, where the testis often shows increased blood flow due to hyperemia. A normal Doppler study with edema or other nonspecific findings doesn’t support torsion, and testicular enlargement with a hydrocele is not diagnostic on its own. The key point is that decreased or absent testicular blood flow on Doppler is the strongest indicator of torsion requiring urgent evaluation and intervention.