How accurate is ultrasonography in the evaluation of testicular torsion?

Updated: Aug 31, 2018
  • Author: Oreoluwa I Ogunyemi, MD; Chief Editor: Edward David Kim, MD, FACS  more...
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Answer

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%. [17] 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. [27]

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. [28]

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. [29]

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. [30]

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. [31, 32]

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. [33]

In a study of 104 adolescent boys, Boettcher et al found that ultrasound predictors alone were not able to identify all cases of testicular torsion. However, clinical features (pain lasting less than 24 hours, nausea and/or vomiting, abnormal cremasteric reflex, and high position of the testis) were predictive with no false positives reported, thus reducing the negative exploration rate by over 55%. Because scrotal ultrasonography is unpleasant in these cases, Boettcher and colleagues recommend that the procedure be used for diagnosis only in patients who lack the clinical features of testicular torsion. [34]

In a study of 342 patients who presented to the emergency department with acute scrotum pain, Liang and colleagues reported no false-negative findings but a 2.6% false-positive rate on ultrasounds performed to assess for testicular torsion. High rates of the clinical features of sudden-onset scrotal pain (88%), abnormal position of testis (86%), and absent cremasteric reflex (91%) were also reported in the patients with testicular torsion. The investigators concluded that color Doppler ultrasound was accurate and sensitive for diagnosis of torsion.z [35]

Altinkilic et al provided further evidence that routine surgical exploration is unnecessary in patients with symptoms of testicular torsion and a normal color-coded duplex sonography. In their prospective study of 236 patients with clinical suspicion of testicular torsion, the sensitivity, specificity, and positive and negative predictive values of color coded duplex sonography were 100%, 75.2%, 80.4%, and 100%, respectively. [36]

In a review of 155 surgical explorations for acute scrotal pain, Nason el al reported rates of 96.9%, 88.9%, 96.9% and 89% for sensitivity, specificity, and positive predictive value and negative predictive value, respectively, for Doppler ultrasound used to assess testicular torsion. [37]

McDowall et al reported that the whirlpool sign—a spiral-like pattern seen on assessment of the spermatic cord, using standard high-resolution ultrasonography and/or color Doppler sonography—is a definitive sign for testicular torsion in pediatric and adult patients, but has a limited role in neonates. In their meta-analysis, the whirlpool sign had a pooled sensitivity and specificity of 0.73 (95% CI, 0.65-0.79) and 0.99 (95% CI, 0.92-0.99), respectively. Removal of neonates increased the pooled sensitivity to 0.92 (95% CI, 0.70-0.98) while the pooled specificity remained almost unchanged. [38]


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