Micturating Cystourethrography (MCU)

A micturating cystourethrography (MCU) is an X-ray examination that allows doctors to look at how the bladder works while the person is passing urine. This will also allow detection of vesicoureteric reflux (VUR).

Vesicoureteric reflux (VUR) is a condition where urine goes back up the ureter (the tube connecting the kidneys to the bladder) instead of going out normally through the urethra (which drains urine from the bladder) only.

Does the test hurt?
The test is not painful. Your child may feel discomfort when we put in a thin plastic tube into the bladder. The tube is called a catheter, and it will be inserted gently by our nurses before the examination.

Should my child be hospitalised for the procedure?
The examination does not usually require hospital admission. It can be performed on an outpatient basis. However, if your child is hospitalised on the appointment day, please tell the ward staff to inform the Department of Diagnostic and Interventional Imaging (DDII).

How can I prepare my child for the MCU?
As your child may be anxious about the test, we strongly encourage you to talk through the procedure with your child to help him/her understand what will be happening. This will help him/her lie still and cooperate during the test to ensure a smooth examination.

Your child does not have to fast for the procedure. He/she may continue to eat, drink, and take all prescribed medications as usual.

Please arrive 30 minutes before your appointment time to register and give your child time to relax and prepare for the test. 

You may wish to bring along a toy or book for your child and milk feed (if required). An MCU usually takes about 30 to 45 minutes to complete. However, the whole visit may take up to a few hours when a child is unable to cooperate or when we have an emergency that requires the medical team to attend to first.

What happens during a MCU test?
Before the examination, the nurse will gently insert a catheter through the urethra into the bladder. The urethra is the channel through which the urine passes out of the body.

During the examination, your child will be lying on the X-ray couch. The radiologist will fill the bladder slowly with contrast medium (X-ray dye). The contrast enables the bladder to be seen under X-ray.

While the bladder is being filled, a camera above the child will take X-ray pictures of it. Several images will be taken in different positions, the radiographer and radiologist will assist your child’s position and movement during the test.

If your child is an infant, he/she will usually pass urine as soon as the bladder is full enough to produce an urge to pee. An older child will be asked to pass urine after their bladder is filled. Pictures will be taken as the bladder empties and the contrast passes out. The catheter will be removed at the end of the examination by the radiologist.

Radiation dose
The radiation dose your child will receive is small. As such, there are no side effects from the radiation.

How will I know the results of the test?
When the MCU report is ready, your doctor in the clinic will review it together with the results of other tests your child may have done. They will discuss the MCU results and other findings with you during your child's medical review.

Important points to note:
After the test, your child should drink plenty of water to flush the contrast out of his/her body. In the unlikely scenario your child feels any pain or discomfort while trying to pass urine, you may let him/her sit in a bath of warm water to pass urine.

Please ensure that your child completes the course of antibiotics prescribed by your doctor for the examination as advised. This is required to prevent any possible (but infrequent) risk of infection during catheterisation.