Retrograde Urethrogram (RUG)

Indications

• Suspected urethral injury/trauma (esp. pelvic fracture, blood at meatus)
• Urethral stricture evaluation (location, length, caliber)
• Urethral fistula or false passage
• Periurethral abscess/diverticulum
• Pre/post urethroplasty assessment

Patient prep

• Sterile preparation of penis/meatus
• Explain procedure; typically performed in males (anterior urethra)
• Perform before catheterization if urethral injury suspected

Contrast

Technique

• Position patient ~45 degrees oblique (RPO/LPO) with penis stretched over the thigh
• Place a small catheter with balloon inflated in the fossa navicularis, or use a penile clamp/syringe adapter at the meatus
• Inject water-soluble contrast slowly under fluoroscopy to distend the anterior urethra
• Acquire spot images during active injection (urethra opacified/distended)
• Assess for extravasation, stricture, false passage; contrast normally enters the bladder if no obstruction

Series / Sequences

Key points

• In trauma with suspected urethral injury, RUG should precede catheter placement to avoid converting a partial to complete tear
• Extravasation patterns help classify injury (anterior vs posterior; Goldman classification)
• Inject only water-soluble iodinated contrast; avoid air bubbles (mimic stones/lesions)
• Combine with VCUG (antegrade) for full anterior + posterior urethral assessment (up-and-down urethrogram)
• Steady gentle injection avoids intravasation/reflux into veins

References