Diagnosis of testicular torsion

Diagnostic tests

Despite all the physical signs and clinical acumen of the physician, most doctors order some type of radiological test to confirm the diagnosis of testicular torsion. Only in the rare exceptional cases, where the diagnosis is unequivocal is surgery done without further studies. In all cases where the diagnosis is in doubt, diagnostic testing is highly recommended.

The most commonly used radiological tests to asses the scrotum are Doppler ultrasonography, radionuclide imaging, and surgical exploration.

Ultrasound

Blood flow in the testes can easily be evaluated by ultrasound. In patients with testicular torsion, the blood flow in the affected testis is decreased or absent compared with the asymptomatic testis. In addition, the affected testicle appears to be enlarged. Initially, the testicle may also reveal increased echogenicity once the testes is twisted and starts to die.

Doppler ultrasonography also can differentiate between ischemia of the testes and inflammation of the epididymis. Ultrasound also can reveal the presence of other testicular disease (e.g., torsion, tumor, hydrocele, hematoma, and varicocele).

In some cases, the Doppler ultrasound can miss the diagnosis of testicular torsion, especially when the torsion is only partial. In addition, the technique can also show falsely suggest testicular torsion, when none is present. This is particularly so in younger teenagers and children with smaller prepubescent testicle. Doppler ultrasonography is not 100% sensitive for testicular torsion.

Radionuclide study

Radionuclide studies are 100% sensitive for the diagnosis of testicular torsion. Individuals with suspected torsion are injected with a small amount of a radioactive chemical which flows into the blood vessels. When the blood flow to the testes is obstructed, the radionuclide will not show up in the testes. In cases of inflammation or infection, there is more flow of the tracer to the testis.

Radionuclide study is the gold standard and 100% sensitive for the diagnosis of torsion. However, the test is not always readily available and does take a few hours to perform. In contrast, ultrasonography is faster and more readily available. This is important to know when dealing with testicular torsion- a condition that depends on rapid diagnosis for a positive outcome.