From the Guidelines
Scrotal ultrasound is the preferred initial imaging modality over CT with contrast for evaluating scrotal pathology, particularly in cases of acute onset of scrotal pain without trauma or antecedent mass, due to its superior soft tissue resolution, lack of radiation exposure, and ability to assess blood flow using Doppler techniques 1.
Key Benefits of Scrotal Ultrasound
- Offers superior soft tissue resolution for testicular and scrotal structures without radiation exposure
- Allows for real-time imaging and assessment of blood flow using Doppler techniques
- Can detect abnormalities as small as 1-2 mm
- More cost-effective and widely available compared to CT with contrast
- Does not require contrast agents that might cause allergic reactions or nephrotoxicity
Clinical Applications of Scrotal Ultrasound
- First-line imaging modality for conditions such as testicular torsion, epididymitis, orchitis, hydrocele, varicocele, testicular trauma, and suspected testicular masses
- Ideal for serial examinations when monitoring conditions over time due to its non-invasive nature
Limitations of CT with Contrast
- Not routinely used as an initial imaging modality for the evaluation of acute scrotal pain without trauma and without antecedent mass 1
- May be preferred when evaluating for metastatic spread of testicular cancer to retroperitoneal lymph nodes or when ultrasound findings are inconclusive and broader abdominal/pelvic assessment is needed
Recent Guidelines and Recommendations
- The American College of Radiology Appropriateness Criteria recommend scrotal ultrasound as the initial imaging modality for acute onset of scrotal pain without trauma or antecedent mass 1
- Contrast-enhanced ultrasound (CEUS) and US shear-wave elastography (SWE) are gaining clinical acceptance as useful additions to first-line US examinations of the scrotum in patients with newly diagnosed palpable scrotal abnormality 1
From the Research
Comparison of Scrotal Ultrasound and CTAP with Contrast
- Scrotal ultrasound is preferred over CTAP with contrast in certain situations due to its high diagnostic accuracy, non-invasiveness, and lack of ionizing radiation 2, 3, 4.
- Ultrasound is particularly useful in evaluating acute scrotal conditions, such as testicular torsion, epididymo-orchitis, and varicocele, with high sensitivity and specificity 2.
- In cases of subacute testicular torsion, scrotal ultrasound may be misleading and should not be relied upon as the sole diagnostic tool 5.
- Contrast-enhanced ultrasound (CEUS) can be useful in patients with acute scrotal pain or scrotal trauma when the diagnosis remains inconclusive after initial ultrasound evaluation 6.
- CEUS has been shown to have higher sensitivity and specificity compared to traditional ultrasound in certain cases, potentially reducing the need for further imaging 6.
Specific Situations Where Scrotal Ultrasound is Preferred
- Acute scrotal pain or swelling, particularly in pediatric and adolescent populations 2, 3, 4.
- Evaluation of testicular torsion, epididymo-orchitis, and varicocele 2.
- Scrotal trauma or injury 3, 4.
- Detection and characterization of intratesticular and extratesticular masses 3.