Micturating cystourethrogram (MCUG)

What is an MCUG?

A micturating cystourethrogram (MCUG) is an X-ray scan that looks at the bladder, ureters (tubes that carry wee from the kidneys to the bladder), and urethra (wee tube leaving the bladder).

We do the scan so that we can see what these structures look like and how the work. We use a special dye inserted into the bladder via a catheter (rubber tube). This dye acts like wee so we can see what happens to wee when it is in the bladder.

Why does my child need an MCUG?

Children have a MCUG for many reasons. Your child’s medical team will explain to you their reasons for choosing to do this scan. We can use a MCUG to help find a cause for your child’s symptoms or plan their treatment.

Are there any risks?

A MCUG is a safe scan, although as with everything we do there are risks.

The main risk is that your child may develop a wee infection after having the scan. To reduce this risk, we will give your child a 3-day course of antibiotics over the time of the scan. Only 1 in every 100 children who have this scan will get a wee infection after. Most of the time your GP can treat these infections.

Your child may be uncomfortable during the scan because of the catheter and having to remain still for the pictures. Your child should not be uncomfortable after we have completed the scan and removed the catheter.

Your child’s medicines will not react with the dye that we use. Your child will wee any remaining dye out of the bladder over the next day.

We use weak X-rays, known as fluoroscopy, during a MCUG. We do not expect these to cause any long-term damage.

What will happen before the MCUG?

Your child’s doctor will ask the radiology team to do the MCUG. We will give you a time to attend the hospital for the scan. Please let us know as soon as possible if you cannot make your given time so that we can make you a new appointment.

Your child’s doctor will talk to you and your child about the best way to put the catheter in on the day of the scan. Some children have this done when they are asleep under anaesthesia. Some children have it done when they are awake in the scan room.

Your child will need to take antibiotics for 3 days. This will start the day before the scan and finish the day after. Your child’s hospital doctor or GP will provide you with a prescription for this.

If your child is already on preventative antibiotics, we will need to increase the dose to a ‘treatment’ level for the same 3-day period. Your child can return to their preventative dose after they have completed the treatment course.

Rules about Covid-19 testing are changing all the time. The hospital will tell you if your child needs a Covid-19 test before coming for their scan.

What will happen on the day of the scan?

On the day of the scan please attend the hospital at the time stated on your letter. The letter will tell you where you need to go first.

The person bringing your child needs to have ‘Parental Responsibility.’ This is the person who can legally make decisions for the child. If the person who brings your child does not have ‘Parental Responsibility,’ we may have to cancel the scan.

Because we use X-rays for the scan, legally we must ask all children over 12 years old with internal reproductive organs if there is any possibility that they may be pregnant. We may also do a pregnancy test. This is to protect any developing baby from X-ray radiation if your child does happen to be pregnant.

If the person bringing your child is pregnant, they will not be able to go into the scan room. If this is the case, a second person may come with your child to stay with them during the scan.

We will call your child into the scanning room. You or the accompanying adult can stay with your child all the time. Your child will need to put on a hospital gown and remove their clothes from the waist down. They will then go on to the scanning bed. We will put a catheter into your child’s bladder through the wee tube. Your child may find this uncomfortable. If you child already has a catheter, we will use this for the scan.

Your child will need to stay as still as possible during the scan. Sometimes we need to hold them still, and we may ask for help with this from the accompanying adult. Your child can have a toy, book, or device to distract them during the scan.

When everyone is ready, we will put dye into the bladder through the catheter. We will then take X-ray pictures to look at what happens to the dye in the bladder. We will ask your child to wee into a pan so we can look at what happens when the dye leaves the bladder. Smaller children will wee automatically when their bladder is full. When we have enough X-ray pictures, we will remove the catheter.

The scan takes about 30 minutes. You are free to leave after we have finished the scan.

What will happen afterward and when will we get the results?

The radiology doctor will look at the X-ray pictures and write a report on what they show. The radiology team will send the report to your child’s doctor, who will talk to you about it at your next appointment.

After the scan, your child should drink plenty of water or squash to help get rid of any dye left behind.

Please remember to finish your child’s course of antibiotics until the day after the scan.

What should I look out for?

If your child becomes unwell after the scan including:

• pain when weeing
• tummy pain
• high temperatures
• being sick

Please take them to see your GP or visit your local hospital Emergency Department.