Micturating Cysto Uretherogram (MCU)

Disclaimer: This fact sheet is for education purposes only. Please consult with your doctor or other health professional to make sure this information is right for your child.

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What is a cystogram (MCU)?

MCU is a test that makes it possible to look at your child's bladder and kidneys using a special contrast liquid under x-ray. 

What is contrast?

Contrast is a clear liquid containing a radiopaque substance which makes the bladder and kidneys easier to see.  All the contrast passes out of the body very quickly in the urine. 

What happens in MCU examination?

The MCU is a test carried out in the Medical Imaging Department at The Children’s Hospital at Westmead and at Prince of Wales Medical Imaging at Sydney Children’s Hospital Randwick.  In this examination, a series of XRay’s are taken of your child’s bladder and kidneys.

The test is performed in a room with an X-Ray table and a large camera above it.  The camera is linked to a television screen where an X-Ray image of the bladder, kidneys and urethra can be observed.

The nurse will lay your child on the table and you are asked to stand near your child’s head so you can talk to him/her and hold his/her hands.  The doctor will clean your child’s groin with antiseptic solution.  Local anaesthetic gel is placed on the end of a tiny plastic tube, called a catheter, (at some of hospitals the anaesthetic gel is injected into the penis for boys).  The tip of the catheter is passed into the bladder. The catheter used is smaller than the child’s urethra.   This can cause discomfort and may upset your child.  It is important that you reassure and comfort your child.

The catheter is then connected to the bag of contrast liquid, which is hung by the side of the table. As the bladder fills, the contrast liquid makes the bladder look like a black balloon. This is watched on the TV screen and a series of X-Ray films are taken in different positions.  Once the bladder is full, X-Ray images of the kidneys and bladder are taken.  Pictures are also taken as it empties.  The filling up and emptying of the bladder may be repeated during the examination.

Special nappies or bluey’s are placed under the child while he/she is emptying his/her bladder.  It is important that you explain to them that they need to pass urine while lying on the X-Ray table which can be difficult especially for children who are toilet trained.  A urinary bottle or bedpan can be given to an older child.

As the contrast fluid flows out of the bladder, the tube will be slid out. Once the bladder is empty and the final images have been taken, the test is finished and your child will be cleaned and can get dressed.  The doctor checks the pictures and the examination is complete.

Advice for parents                                                              

  •  If your child has a cardiac condition, please ask your cardiologist for the correct antibiotic cover.
  • It is very important that your child is not suffering from a urinary tract infection currently or for the 2 weeks prior to the test.
  • Your child will be requested to take antibiotics the day before, the day of and the day after the examination according to the doctor’s instructions – this is to reduce the risk of Urinary Tract Infection after the procedure.
  • Encourage your child to drink plenty of fluids for 24 hours after the test so as to flush the bladder.
  • Your child may be a little sore when they go to the toilet for the rest of the day, but this sensation will go away quickly.
  • Urine might be bloodstained in the 24 hours following the test, but it will return to normal.
  • If your child is unwell, such as a fever, continuous bloodstained urine or blood clot, you should take your child to see your GP or attend The Children’s Hospital at Westmead or Sydney Children’s Hospital Randwick Emergency Departments.      
  • MCU can be an uncomfortable procedure for older children because of the lack of privacy and the need to urinate while lying on a table. Nitrous oxide is available for children 1-2 years and older.
  • You may ask your doctor if your child is medically suitable for nitrous oxide so the referring doctor may request MCU with nitrous oxide on the request form. 
  • For further information on nitrous oxide it is recommended that you contact the Medical Imaging Department to speak to the nurse.


  • Your child will feel more comfortable if a parent or carer stays with them during the examination.
  • Women who are pregnant are not allowed to enter the procedure room, therefore an alternative family support person is recommended.
  • If you have other children, under 18 years, it is suggested where possible, that these children do not accompany you to the appointment, as there is limited waiting space in the Medical Imaging area and they are not allowed into the procedure room with you.
The Children's Hospital at Westmead
Sydney Children's Hospital, Randwick
Hunter New England Kids Health

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