Testicular Torsion Workup

If testicular torsion is clinically suggested, perform immediate surgical exploration, regardless of laboratory studies because a negative finding upon exploration of the scrotum is more acceptable than the loss of a salvageable testis.

Laboratory tests are unlikely to be of consequence, as no single test has high sensitivity or specificity in diagnosing testicular torsion. However, when there is a strong suspicion of an alternate diagnosis, laboratory tests may be of some use.

Imaging studies usually are not necessary. Ordering them wastes valuable time when the definitive treatment is emergent urologic consultation for surgical management. However, imaging studies (eg, ultrasonography, nuclear scans) may be useful when a low suspicion of testicular torsion exists.

If the patient does not show clinical evidence of testicular torsion, a urinalysis and culture may help exclude urinary tract infection and epididymitis as the etiology of the scrotal complaints.

Urinalysis results are usually normal in testicular torsion. The presence of white blood cells (WBCs) can be observed in as many as 30% of patients who have torsion; therefore, do not rely on the presence of WBCs to exclude the diagnosis.

The complete blood count can be normal. However, the WBC count is elevated in as many as 60% of patients who have torsion.

Elevation in acute-phase proteins (ie, C-reactive protein) has been postulated as a diagnostic aid in differentiating inflammatory causes of acute scrotal pain (eg, epididymitis) from noninflammatory causes (eg, testicular torsion).^[19] However, sample sizes in these studies have been too small to support using CRP as a diagnostic adjunct to definitively rule out testicular torsion.

Testicular torsion is a clinical diagnosis. If the history and physical examination strongly suggest testicular torsion, the patient should go directly to surgery without delaying to perform imaging studies.

When a low suspicion of testicular torsion exists, color Doppler and power Doppler ultrasonography can be used to demonstrate arterial blood flow to the testicle while providing information about scrotal anatomy and other testicular disorders. (For images, see Testicular Torsion Imaging.)

Plain Doppler ultrasonography is less accurate than color Doppler in assessing testicular blood flow. In fact, early in the course of testicular torsion, gray-scale ultrasonographic examination may be absolutely normal.

Ultrasonographic findings suggestive of acute testicular torsion include the following^[20] :

• Absent or decreased blood flow in the affected testicle
• Decreased flow velocity in the intratesticular arteries
• Increased resistive indices in the intratesticular arteries
• Hypervascularity with a low resistance flow pattern (after partial torsion-detorsion)

The sensitivity of color Doppler examination with newer ultrasonography equipment in detecting acute testicular torsion in children is 90-100%, with the specificity of technically adequate studies being essentially 100%.^[11] Other studies have suggested that color Doppler ultrasonography was only 86% sensitive, 100% specific, and 97% accurate in the diagnosis of torsion and ischemia in the painful scrotum.^[21]

A 3-year study demonstrated that Doppler ultrasonography had 94% sensitivity, 96% specificity, 95.5% accuracy, 89.4% positive predictive value, and 98% negative predictive value.^[22]

The detection of a color or power Doppler signal in a patient presenting with the clinical findings suggestive of testicular torsion does not absolutely exclude torsion. Clinical correlation should be incorporated in the evaluation of acute scrotum because color Doppler ultrasonography is not 100% sensitive.^[23]

Spectral and color flow Doppler sonography has also been used to evaluate for partial testicular torsion. Variability of the Doppler waveform when compared with the contralateral testicle and reversal of diastolic blood flow are indirect clues that aid in the diagnosis of partial testicular torsion.^[24]

Some smaller studies have evaluated the accuracy of emergency medicine physicians in performing bedside ultrasonography to evaluate for testicular torsion. While these studies have had generally favorable outcomes, diagnostic accuracy is always operator and institution dependent.^{[25, 26]}

A study of the use of contrast-enhanced ultrasonography demonstrated no advantage of this modality over Doppler ultrasonography in the evaluation of the acute scrotum. Contrast-enhanced ultrasonography can, however, be used as a supplement to traditional Doppler sonography when the diagnosis is uncertain and following appropriate clinical and radiographic evaluation.^[27]

Small studies to date suggest that magnetic resonance imaging (MRI), particularly when performed with contrast enhancement, is highly accurate in the diagnosis of testicular torsion, particularly when torsion knot or whirlpool patterns are evident.

Dynamic contrast-enhanced MRI has also demonstrated accuracy.^[28] The clinical utility of these studies, however, remains to be elucidated.

If the diagnosis is equivocal, radionuclide scan of the testicles can be helpful to assess blood flow and to differentiate torsion from other conditions. (For images, see Testicular Torsion Imaging.) These studies should preferably be ordered once urologic consultation has been completed and only for equivocal presentations.

Scan results are abnormal in torsion when they demonstrate decreased uptake in the affected testicle, suggesting no blood flow to that side. Radionuclide scans have a sensitivity of 90-100% accuracy in detecting testicular blood flow.