A cystogram is a fluoroscopy-based examination of the bladder. Iodine-based contrast dye is gently introduced into the bladder through a thin catheter, and real-time X-ray images are taken to show the bladder filling, distending, and emptying. It is one of the most direct ways to look at the bladder wall, the bladder outlet, and the path the urine takes out of the bladder.
Common Indications for a Cystogram
Your doctor may request a cystogram to:
- Investigate suspected injury to the bladder after pelvic trauma or surgery.
- Detect a fistula — an abnormal connection — between the bladder and bowel, vagina, or skin.
- Look for diverticula (small outpouchings of the bladder wall).
- Evaluate persistent urinary leakage after pelvic surgery.
- Assess the bladder before reconstructive urological surgery.
- Investigate recurrent urinary tract infections in adults.
For children with suspected vesicoureteral reflux, the related test is a voiding cystourethrogram (VCUG) — which also images the urethra during urination.
What exactly does a cystogram show?
The scan shows:
- The shape and contour of the bladder when filled.
- Whether contrast leaks out of the bladder into the surrounding tissues (bladder rupture).
- Whether contrast travels backward up the ureters toward the kidneys (vesicoureteral reflux).
- Whether contrast tracks into the bowel, vagina, or skin (fistula).
- The position of the bladder relative to surrounding structures.
What happens during the procedure?
- You change into a gown and lie on the X-ray table.
- The radiographer cleans the area around the urethral opening.
- A thin catheter is gently passed into the bladder through the urethra. This is the most uncomfortable part — it usually feels like pressure rather than pain, and lasts only a few seconds.
- Sterile iodine-based contrast is slowly run into the bladder through the catheter.
- The radiologist watches the bladder fill on the fluoroscopy screen and takes X-ray images at standard points — partially filled, fully filled, and (in some types of cystogram) while you urinate.
- For some indications, the bladder is emptied through the same catheter; for others, you are asked to urinate yourself so post-void images can be taken.
The whole procedure usually takes 20 to 40 minutes.
Do I need to prepare?
- You may be asked to empty your bladder before the test starts so it can be filled cleanly with contrast.
- No fasting is required.
- Wear comfortable clothing — you will change into a gown.
- Tell the team if you have ever had a reaction to iodine-based contrast.
- Tell the team if there is any chance you are pregnant.
Will the test be painful?
The most uncomfortable part is the catheter insertion. This is a brief sensation of pressure or stinging, lasting a few seconds. Once the catheter is in place, the rest of the test is generally well tolerated. The bladder may feel uncomfortably full at maximum filling — tell the radiographer if it becomes painful.
After the test, you may feel mild burning when urinating for the first day or two, which usually resolves on its own.
How long do the results take?
A radiologist usually reviews images during the procedure and gives a preliminary impression at the end. The formal report typically reaches your doctor within 24 to 72 hours.
Are there risks?
Mostly minor risks, but worth knowing
The main risks of a cystogram are:
- Urinary tract infection — uncommon with sterile technique. Follow individualized fluid advice. Fever, chills, worsening pelvic or flank pain, inability to pass urine, or feeling systemically unwell requires prompt medical assessment.
- Mild burning when urinating — usually self-limiting.
- Blood in the urine — usually mild, related to the catheter, and resolves quickly.
- Contrast reaction — rare, since the contrast stays in the bladder rather than entering the bloodstream.
- Radiation exposure — the team should verify pregnancy possibility where relevant and decide whether to defer, modify, or proceed based on the clinical urgency; pregnancy is not managed by a blanket rule.
Call your doctor if you develop fever, chills, severe pain, persistent heavy bleeding, or inability to urinate after the test.
What if reflux is found?
Vesicoureteral reflux is more commonly investigated in children with a VCUG. In adults, it is uncommon and usually managed conservatively unless it is causing kidney damage or recurrent infections.
What if a leak or fistula is found?
A bladder leak after trauma usually settles with prolonged catheterisation (1 to 2 weeks of free drainage) and a repeat cystogram to confirm healing. Large or complex leaks may need surgical repair. Fistulas almost always need surgical management.
What are the important limitations and safety checks?
Fluoroscopy shows movement or anatomy during a specific examination, but it does not guarantee a diagnosis or exclude every abnormality. Image quality and interpretation can be limited by positioning, movement, body size, retained contrast, overlying structures, incomplete filling, or the patient's ability to complete the study. Further endoscopy, ultrasound, CT, MRI, laboratory testing, or tissue sampling may still be needed.
Fluoroscopy uses ionising radiation. Dose varies with the body area, examination complexity, equipment, patient size, and imaging time; the team should use the lowest exposure that still answers the clinical question. Tell the team before the examination if you are or may be pregnant. Pregnancy does not create a universal ban: the referrer and imaging team should decide whether to defer, modify, or proceed when the expected benefit outweighs the risk.
Contrast and preparation are procedure-specific. Barium, water-soluble iodinated contrast, intravenous contrast, and contrast placed into a joint, bladder, uterus, duct, or fistula have different risks. Tell the team about prior reactions, swallowing or aspiration problems, suspected perforation, kidney or thyroid disease, diabetes, medicines, and recent contrast studies. Do not fast, stop medicines, interrupt breastfeeding, or take bowel preparation or antibiotics based only on a general webpage; follow the center's written instructions.
Questions to ask the fluoroscopy team
- What exact question should this examination answer, and is a radiation-free or non-invasive alternative suitable?
- Which contrast route and agent will be used, and what preparation, pregnancy, breastfeeding, allergy, kidney, diabetes, or medicine instructions apply to me?
- Will a catheter, internal examination, sedation, or pain relief be needed, and may I stop the procedure if I am uncomfortable?
- What symptoms require urgent help afterward, when will the signed report be ready, and who will explain the result?
Sources and further reading
- RadiologyInfo.org: Fluoroscopy
- American College of Radiology: Manual on Contrast Media
- RadiologyInfo.org: Radiation safety for children
Conclusion
A cystogram is a focused fluoroscopy study that directly answers questions about bladder integrity, drainage, and connections to nearby structures. It is fast, mostly comfortable, and provides immediate visual answers that other tests cannot. The catheter insertion is the only mildly uncomfortable part — the rest of the test is well tolerated, and the diagnostic value is high when used for the right clinical question.