Retrograde Urography

GU Studies

47 Retrograde Urography

Kidneys: cortex, medulla, renal pyramids, renal papillae, minor and major calyces, renal pelvis, hilum.
Ureters: extend from renal pelvis to urinary bladder, following lumbar curve.
Bladder and urethra: may be partially evaluated during catheterization.
Collecting system focus: pelvicaliceal system and ureters are best opacified with retrograde filling.

Indications

Renal insufficiency or patients with contraindications to IV contrast (e.g., allergy, poor renal function).
Anatomic evaluation of pelvicaliceal system and ureters when IVU is inconclusive.
Evaluation of ureteral obstruction, stricture, or mass.
Direct urine sampling from each kidney for culture and microscopic analysis.

Contraindications

Active urinary tract infection (risk of worsening infection with instrumentation).
Severe urethral trauma (catheterization contraindicated).
Patients unable to tolerate anesthesia or cystoscopy.

Patient Preparation

SID: 40 inches.
Patient Position & Adjustments: Supine in modified lithotomy position (knees flexed in stirrups).
CR Location & Positioning: Perpendicular, centered midway between xiphoid process and iliac crests (kidney level).
Pt. Instructions: Suspend respiration on expiration.
Evaluation Criteria: Demonstrates ureteral catheters in place prior to injection.

SID: 40 inches.
Patient Position & Adjustments: Supine; some protocols lower head of table 10–15° Trendelenburg to retain contrast in renal pelvis.
CR Location & Positioning: Perpendicular, centered at kidney level.
Pt. Instructions: Suspend respiration at end of expiration.
Evaluation Criteria: Pelvicaliceal system completely opacified with contrast; no motion; kidneys symmetrically visualized.

SID: 40 inches.
Patient Position & Adjustments: Supine; head of table elevated 35–40° to show tortuosity and mobility of ureters.
CR Location & Positioning: Perpendicular, centered at iliac crests.
Pt. Instructions: Deep inspiration, suspend on full expiration during exposure.
Evaluation Criteria: Ureters outlined as catheters are withdrawn with contrast injection; mobility of kidneys and ureters demonstrated.

AP Obliques (RPO/LPO): demonstrate ureteral course, remove superimposition.
Lateral: performed for anterior displacement of kidney/ureter or suspected perinephric abscess.
Decubitus Lateral: ventral or dorsal positioning may aid in evaluating ureteropelvic region (hydronephrosis).

Bilateral studies: Both ureters filled simultaneously to minimize radiation exposure.
Dilated collecting system: Larger contrast volumes may be required.
Pediatric patients: Reduced catheter size and contrast volume.
High-risk patients: Performed in collaboration with anesthesiology and urology team.

Contrast: Nonionic iodinated contrast, instilled directly via catheter.
Volume: 3–5 mL for average renal pelvis (larger if dilated).
Technique:
- Contrast delivered via ureteral catheters during cystoscopy.
- May apply pressure to syringe during injection (urologist discretion).
kVp: 75–85.
SID: 40 inches.
Radiation Protection: Gonadal shielding when possible, unless it obscures anatomy.

Why is retrograde urography used instead of IVU in some patients?
Because it bypasses systemic circulation, making it safer for patients with poor renal function or contrast allergy.
Why is cystoscopy required?
To localize ureteral orifices and allow catheter passage into the ureters.
Why might the head of the table be lowered during a pyelogram?
To keep contrast in the pelvicaliceal system and prevent premature drainage into ureters.
Why might the head of the table be raised during a ureterogram?
To demonstrate ureteral tortuosity and mobility.
Why is retrograde urography considered an operative procedure?
Because it requires instrumentation (cystoscopy, catheterization) under aseptic technique with physician, nurse, and technologist working together.
Why is patient sensation of fullness important?
It indicates the renal pelvis is adequately filled with contrast.
Why are respiration instructions emphasized (expiration breath-hold)?
To reduce motion and improve visibility of contrast-filled collecting system.