Acute Scrotal Pain Evaluation and Management

Clinical Assessment and Risk Stratification

The American College of Radiology recommends US Duplex Doppler of the scrotum as the initial imaging modality of choice for evaluating acute scrotal pain, with a focus on assessing testicular perfusion and identifying the "whirlpool sign" of twisted spermatic cord 1, 2
The TWIST score can be used to stratify risk, with a score of 0 indicating low risk, 1-5 indicating intermediate risk, and 6-7 indicating high risk, guiding the need for urgent imaging or surgical exploration 1
Patients with a high TWIST score (6-7) or clinical presentation strongly suggestive of torsion should proceed directly to surgical exploration without delaying for imaging, as testicular salvage rates decline significantly after 6-8 hours 1

Ultrasound examination should include grayscale, color Doppler, and power Doppler assessments to evaluate testicular homogeneity, perfusion, and identify signs of torsion, such as the "whirlpool sign" or decreased/absent blood flow 1, 2
Critical ultrasound findings for testicular torsion include decreased or absent blood flow, "whirlpool sign", and enlarged heterogeneous hypoechoic testis, while epididymitis/epididymo-orchitis is characterized by enlarged epididymis with increased blood flow and scrotal wall thickening 1, 2

Prepubertal boys are at higher risk for torsion of testicular appendage, while adolescents and young adults are at higher risk for testicular torsion, and adults over 25 years are at higher risk for epididymitis/epididymo-orchitis 1, 2
Immediate urological consultation is mandatory for patients with intermediate or high TWIST score, or any acute scrotal pain where torsion cannot be definitively ruled out clinically 1

Segmental testicular infarction, acute idiopathic scrotal edema, and scrotal fat necrosis should be considered in the differential diagnosis, and normal urinalysis does not exclude testicular torsion or epididymitis 1, 2
False-negative Doppler evaluations can occur with partial torsion or spontaneous detorsion, and significant overlap exists in clinical presentation between different causes of acute scrotal pain, highlighting the need for careful evaluation and risk stratification 1