Diagnosis of Testicular Torsion
Testicular torsion should be diagnosed through a combination of clinical assessment and Doppler ultrasound, with immediate surgical exploration indicated when high clinical suspicion exists regardless of imaging results. 1
Clinical Assessment
Key History Elements
- Sudden onset of severe scrotal pain
- Timing of symptom onset (critical for determining testicular salvage potential)
- Nausea and vomiting (common accompanying symptoms)
- Absence of urinary symptoms or fever (which may suggest epididymitis)
- Previous episodes of similar pain that resolved spontaneously (may indicate intermittent torsion)
Critical Physical Examination Findings
- Absent cremasteric reflex (most accurate sign of testicular torsion) 2
- High-riding testis with horizontal lie
- Swollen, tender testicle
- Negative Prehn's sign (pain not relieved by elevation of scrotum) 3
- Positive Deming's sign (testicular rotation) 3
- Scrotal skin erythema and edema
Diagnostic Imaging
Ultrasound with Doppler (First-Line Imaging)
- Sensitivity: 69-96.8%, Specificity: 87-100% 1
- Key findings:
- Absent or decreased blood flow in affected testis
- Enlarged, heterogeneous, possibly hypoechoic testis
- Ipsilateral hydrocele and skin thickening
- Twisted spermatic cord ("whirlpool sign")
- Spectral Doppler analysis should be performed at upper, mid, and lower poles of each testicle 1
Partial Torsion Findings on Doppler
- Diminished arterial velocity
- Decreased diastolic flow with increased resistive index
- Absent or reversed diastolic flow
- Variability in spectral Doppler waveform amplitude
- Monophasic waveform or tardus-parvus morphology 1
Nuclear Medicine Scan (Second-Line)
- Largely replaced by Doppler ultrasound
- Sensitivity: 89-98%, Specificity: 90-100%
- Limited by technical challenges in children with small genitalia
- May show photon-deficient areas in the affected testis 1
Diagnostic Algorithm
High clinical suspicion (sudden onset pain + absent cremasteric reflex + abnormal testis position):
- Immediate urological consultation for surgical exploration without delay
- Do not wait for imaging if clinical suspicion is high 4
Moderate clinical suspicion:
- Urgent Doppler ultrasound (if available within 30 minutes)
- If ultrasound shows decreased/absent flow: immediate surgical exploration
- If ultrasound equivocal but clinical suspicion remains: surgical exploration
Low clinical suspicion with alternative diagnosis likely:
- Doppler ultrasound to confirm alternative diagnosis
- Close follow-up if non-surgical management chosen
Critical Pitfalls to Avoid
- Delay in diagnosis: Testicular salvage rates drop significantly after 6 hours of torsion 2
- False reassurance from normal Doppler findings: Early or partial torsion may still show blood flow 1
- Misdiagnosis as epididymitis: Especially in adolescents where epididymitis is less common than torsion 4
- Failure to perform bilateral orchiopexy: Contralateral testis is at risk for future torsion 2
- Inadequate follow-up: Any patient with acute scrotal pain and negative imaging should receive daily follow-up until symptoms resolve 4
Differential Diagnosis
| Feature | Testicular Torsion | Epididymitis | Torsion of Testicular Appendage |
|---|---|---|---|
| Onset | Sudden | Gradual | Gradual to sudden |
| Pain relief with elevation | No | Yes (Prehn sign) | Variable |
| Cremasteric reflex | Absent | Present | Present |
| Testicular position | High-riding | Normal | Normal |
| Doppler ultrasound | Decreased/absent flow | Increased flow | Normal testicular flow |
| Specific sign | - | - | "Blue dot sign" (tender nodule with blue discoloration) |
Remember that testicular torsion affects approximately 1 in 4,000 males under 25 years annually, and all prepubertal and young adult males with acute scrotal pain should be considered to have testicular torsion until proven otherwise 2.