Give it a whirl: Sonographic signs to look out for in intermittent testicular torsion

Kelly Foley-Friel, Ultrasound, Medica Diagnostics, Dublin, Ireland

Testicular torsion is a medical urological emergency and one of the most common causes of acute paediatric scrotal pain. Testicular torsion is defined as twisting of the spermatic cord resulting in testicular perfusion disruption. There are different types of torsion: complete, partial or intermittent (Munden et al., 2013). For intermittent testicular torsion, clinical presentation includes acute unilateral scrotal pain with spontaneous resolution.

The cause of intermittent testicular torsion is usually intravaginal and caused by the bell clapper deformity. The bell clapper deformity is a condition where the tunica vaginalis envelopes the testicle, epididymis and distal spermatic cord. As a result, there is no posterolateral attachment of the testicle to the scrotal wall, allowing the testicle to freely twist (Esposito et al., 2014).

Sonographic signs
Sonographic diagnosis of intermittent testicular torsion using colour Doppler proves very difficult, as a patient may have preserved or only subtly decreased intratesticular blood flow. Sonographic appearances that are suggestive include the “whirlpool sign” (a spiral twist of the spermatic cord) and presence of a pseudomass. This sign is highly suggestive even in a testicle with normal blood flow. It can also be seen in complete torsion. A testicular volume discrepancy or abnormal horizontal lie of the testicle along with the patient’s clinical history can additionally raise suspicions.

The probability of salvaging the testicle and sonographic appearances are directly proportional to the onset of clinical symptoms (Esposito et al., 2014). Ultrasound diagnosis is very useful in the differential diagnosis of acute paediatric scrotal pain. When a diagnosis of intermittent testicular torsion is made, patients undergo surgical exploration for detorsion and orchiopexy (Nishizawa et al., 2021). It is important to identify any type of testicular torsion as rapidly as possible, owing to ischemic changes and associated testicular damage.

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