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Sites of scrotal doppler assessment and normal doppler range
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Scrotal Doppler ultrasound evaluates arterial and venous flow in the testes, epididymis, spermatic cord, and scrotal wall. This helps in diagnosing conditions like testicular torsion, varicocele, epididymitis, orchitis, and testicular tumors.
1. Sites of Scrotal Doppler Assessment
A. Testicular Arterial System
The testis receives arterial supply from three main arteries, which must be assessed during Doppler imaging:
Testicular Artery
- Origin: Abdominal aorta
- Supplies: Testis via capsular and centripetal arteries
- Doppler Role: Evaluates overall testicular perfusion
Cremasteric Artery
- Origin: Inferior epigastric artery (branch of external iliac artery)
- Supplies: Scrotal wall and spermatic cord
- Doppler Role: Assists in identifying scrotal wall inflammation
Deferential Artery
- Origin: Internal iliac artery
- Supplies: Epididymis and vas deferens
- Doppler Role: Evaluates epididymal perfusion
B. Intratesticular Arteries
- Capsular Arteries: Encircle the periphery of the testis
- Centripetal Arteries: Arise from capsular arteries and penetrate the testis
- Recurrent Rami: Branches of the centripetal arteries within the testicular parenchyma
- Doppler Role: Evaluates intratesticular perfusion, crucial for torsion detection
C. Pampiniform Venous Plexus (Spermatic Cord Veins)
- Location: Surrounds the testicular artery and drains into the testicular vein
- Doppler Role: Evaluates for varicocele (venous reflux)
- Valsalva Maneuver: Used to assess venous reflux and measure vein diameter
D. Epididymal Vessels
- Epididymal Artery: Branch of the deferential artery
- Doppler Role: Detects epididymitis (increased vascularity)
E. Scrotal Wall Vessels
- Cremasteric artery and vein
- Doppler Role: Assesses scrotal wall edema and inflammation
2. Normal Doppler Ultrasound Ranges
A. Normal Testicular Arterial Flow
o Low-resistance flow pattern (continuous diastolic flow)
| Parameter | Normal Range | Significance |
|---|---|---|
| Peak Systolic Velocity (PSV) | 5–15 cm/s | Normal arterial inflow |
| End-Diastolic Velocity (EDV) | 2–5 cm/s | Should remain positive |
| Resistive Index (RI) | 0.5–0.7 | Indicates normal vascular resistance |
| Pulsatility Index (PI) | 0.6–1.1 | Reflects arterial pulsatility |
B. Normal Venous Flow in Pampiniform Plexus
o Continuous, non-pulsatile flow
o Diameter <3 mm at rest
o No reflux in spectral Doppler
3. Summary Table of Doppler Sites & Normal Values
| Site | Normal Doppler Findings |
|---|---|
| Testicular Artery | Low-resistance flow (RI 0.5–0.7), PSV 5–15 cm/s |
| Capsular Arteries | Uniform low-resistance waveforms |
| Centripetal Arteries | Continuous diastolic flow |
| Pampiniform Plexus | Continuous venous flow, no reflux |
| Epididymal Arteries | Low-resistance flow, mild vascularity |
| Scrotal Wall Vessels | Normal perfusion, no hyperemia |
