RGU (retrograde urethrogram) is an X‑ray study where contrast is injected backward into the urethra to outline its anatomy and detect strictures, trauma or fistula. MCU (micturating cystourethrogram) fills the bladder with contrast via a catheter and images the bladder and urethra while voiding to assess vesicoureteral reflux, posterior urethral valves and causes of recurrent UTIs. Both use fluoroscopic X‑ray imaging.

An MCU (Micturating Cystourethrogram) is an X‑ray test of the bladder and urethra performed while the bladder fills and during urination. Contrast is introduced via a small catheter to visualize anatomy and detect vesicoureteral reflux, strictures or bladder outlet obstruction. It’s used for recurrent UTIs, urinary abnormalities or postoperative assessment. Risks include catheter discomfort, urinary infection and low radiation exposure.

RGU (retrograde urethrogram) is an X‑ray test in which contrast is injected into the urethra to visualize its lumen and surrounding anatomy. It detects urethral strictures, tears, leaks, fistulas, or obstruction and is commonly used after pelvic trauma or when voiding problems occur. Results help plan catheter placement, dilation, endoscopic, or surgical repair.

Both RGU and MCU can cause brief discomfort—pressure, burning, or stinging—during catheter insertion and contrast injection. Local lubrication or anesthetic gel and gentle technique minimize pain. Many patients report only mild discomfort; children may need extra reassurance. Afterwards, some soreness, urinary burning, mild bleeding, or infection risk can occur, but serious pain is uncommon—report severe or lasting pain to your clinician.

Costs vary widely by country and setting. In India an RGU/MCU typically costs about ₹800–₹6,000 at diagnostic centres or private hospitals. In the UK private clinics charge roughly £100–£600 (the public NHS usually covers eligible patients). In the US the procedure (VCUG/retrograde urethrogram) may run about $200 to $3,000+ depending on hospital billing, radiology fees and insurance.

An MCU (micturating cystourethrogram) isn’t needed for every UTI. It’s indicated when children have recurrent febrile UTIs, abnormal renal ultrasound or prenatal hydronephrosis, or when vesicoureteral reflux or urethral obstruction is suspected. Because MCU uses catheterisation and X‑ray exposure, clinicians weigh risks versus benefits and may prefer ultrasound or renal scintigraphy as alternatives. Discuss with your doctor.