1. These AP images are from a retrograde cystogram on a patient with a pelvic fracture. The left image was taken with the bladder distended, and the right image after the bladder was drained. Why is the drained image part of the examination?
Cystogram and VCUG
A retrograde cystogram fills the bladder with contrast through a urethral catheter. A voiding cystourethrogram (VCUG) adds images while the patient urinates, to show the urethra and any reflux of urine up the ureters. Many VCUGs are done on children.
What the ARRT tests
- Retrograde: contrast is put in against the normal flow of urine, through a catheter, by gravity drip, never under pressure.
- Water-soluble iodinated contrast only; the catheter is placed with sterile technique.
- Vesicoureteral reflux (VUR) is shown on the VCUG, often during voiding.
- Cystogram projections: AP with the CR angled 10–15° caudad (so the pubic bones don't hide the bladder base), 45–60° posterior obliques, and a lateral if needed.
- Male voiding images: about a 30° RPO so the urethra is seen clear of the pelvis and thigh. Female: AP.
- A post-void image shows how much contrast is left in the bladder.
Why it's done
- VCUG: urinary tract infections in children, hydronephrosis found on ultrasound, and suspected reflux or urethral valves in boys.
- Cystogram: bladder injury after pelvic trauma, a leak check after bladder surgery, or a fistula.
- Trauma cystograms are often done in CT instead (CT cystogram).
Who's in the room
- Radiologist
- Runs the fluoro, watches the filling and voiding, and takes spots.
- Radiographer or nurse
- Places the catheter with sterile technique (scope of practice varies by state and hospital), sets up contrast, and positions the patient.
- Parent or child life specialist
- Comforts a child and helps them stay still and void on the table.
Step by step
- Before. Confirm the order, allergies, pregnancy status and history of infection. Explain the exam honestly, including that the patient will be asked to urinate on the table.
- Catheter. Sterile prep and catheter placement. Drain the bladder, then hang the contrast and start the gravity drip.
- Filling. The radiologist takes images as the bladder fills, including obliques. For a cystogram, filling continues until the bladder is full or the patient can't hold more.
- Voiding (VCUG). The catheter is removed or left in place, and images are taken as the patient urinates on the table, looking at the urethra and for reflux.
- After. Post-void image, clean the patient, and remind them to drink fluids. Some burning on urination is normal for a day.
Your job
- Strict sterile technique for the catheter (infection risk).
- Absorbent pads and privacy; voiding on a table in front of people is hard for patients.
- For children: small field, pulsed fluoro at a low rate, grid removed if the protocol allows, and a calm room.
Watch out for
- Active infection may postpone the exam; check with the radiologist.
- Contrast reaction is uncommon (little is absorbed from the bladder) but still possible; know the allergy history.
- Never raise the bottle or squeeze the bag to speed filling.
Tips from the room
- Warm the contrast to body temperature for children; cold contrast can cause bladder spasm.
Images
Quick check
2. For the AP projection during retrograde cystography, how is the CR angled to project the pubic bones below the bladder?
3. During a voiding cystourethrogram on a 2-year-old, the radiologist asks the radiographer to remove the grid from the fluoroscopic receptor. What is the rationale?
4. This cystogram shows a contrast-filled urinary bladder with a catheter entering from below. How does contrast reach the bladder in a retrograde cystogram?
5. This cystogram after bladder repair shows the filled bladder (left) and the image after drainage (right), where contrast remains outside the bladder outline at the top. What does this show?
Practice it in 3D
More in the guide
C-arm basics
The parts, the movements, the dose modes, and where to stand.
Sterile basics
What's sterile, what you can touch, and how to move around the field.
Esophagram and upper GI series
Barium swallow and UGI: why they're ordered, the positions, and your role.
Modified barium swallow (swallow study)
Video swallow study with speech therapy: bolus types, the field of view, and your role.
Small bowel follow-through
Timed films as barium moves from the stomach to the colon.
Barium enema
Single- and double-contrast BE: prep, tip insertion, positions, and overheads.
Hysterosalpingogram (HSG)
Uterus and fallopian tubes for infertility: timing, setup, and dose.
Arthrogram
Joint injection under fluoro, usually before MRI or CT.
Myelogram
Contrast in the spinal canal: needle site, table tilt, and keeping contrast out of the head.
Lumbar puncture (fluoro-guided)
Spinal tap under fluoro when bedside attempts fail.
ERCP and cholangiograms
Bile ducts through a scope, in surgery, or through a T-tube.
Hip pinning (hip fracture fixation)
The most common C-arm case: the fracture table, the two views, and your role.
Ankle and wrist ORIF
Open reduction and internal fixation of the ankle or wrist: the views, the mini C-arm, and hands in the beam.