Read more
Gray-Scale (B-Mode) Imaging Scrotal Ultrasound Scanning Protocol
Purpose:
Gray-scale (B-mode) imaging is the primary mode used in scrotal ultrasound to evaluate the anatomy, structure, and echogenicity of the testes, epididymis, and scrotal contents. It helps in detecting masses, fluid collections, testicular atrophy, trauma, and other pathologies.
1. Patient Preparation
- Position: The patient should be in a supine position with the scrotum supported (a towel can be placed under the scrotum to elevate it slightly).
- Warm gel should be applied to prevent cremasteric contraction, which can alter imaging quality.
- A high-frequency linear transducer (7–15 MHz) is recommended for optimal resolution.
2. Transducer Selection & Settings
- High-frequency (7–15 MHz) linear probe for high-resolution images.
- Adjust depth to include the scrotum and its contents while maintaining fine detail.
- Optimize gain settings to distinguish normal from pathological findings.
3. Scanning Planes & Protocol
A. Testes
Transverse (Short-Axis) Views
- Start at the superior pole and scan from superior to inferior.
- Assess echotexture, symmetry, and borders.
- Measure the width and AP (anteroposterior) diameter.
Longitudinal (Sagittal) Views
- Start at the midline and scan medially and laterally.
- Measure the length of each testis.
- Evaluate homogeneity and detect any masses.
Compare Both Testes
- Ensure uniform echogenicity.
- Look for asymmetry in size or echotexture.
- Assess for testicular microlithiasis, masses, or fibrosis.
B. Epididymis
Head (Caput)
- Located superior and lateral to the testis.
- Normally iso- to slightly hyperechoic compared to the testis.
Body & Tail
- Follow along the posterolateral aspect of the testis.
- Evaluate for cystic changes, inflammation, or masses.
C. Scrotal Wall
- Assess thickness and echogenicity.
- Look for edema, thickening, or hematoma.
D. Spermatic Cord
- Evaluate in longitudinal and transverse planes.
- Look for dilated veins (varicocele), abnormal thickening, or masses.
E. Extratesticular Structures
- Identify hydrocele (fluid collection).
- Check for scrotal hernias or other abnormalities.
4. Interpretation Guidelines
- Normal Testis: Homogeneous, medium-level echogenicity.
- Epididymis: Iso- to slightly hyperechoic.
- Hydrocele: Anechoic fluid collection.
- Varicocele: Tortuous, dilated veins (>2 mm).
- Testicular Torsion: Swollen, heterogeneous testis with absent blood flow on Doppler.
- Orchitis/Epididymitis: Enlarged, hypoechoic with increased blood flow.
- Masses: Hypoechoic (testicular tumors) or complex echogenicity (abscess, hematoma).
