Scans and What to Look At

Many parents of kids with BWS become experts in ultrasound.  Here are just a few pointers.  The first thing is that the length of the kidneys  should be measured every time your child is scanned and several measurements  should be obtained of each kidney.  This could be important  in determining the risk of Wilms tumor.    Another important piece of information is that Wilms is not the only thing that can happen to the kidney in BWS.  We have seen cysts, diverticula (cysts that connect to the urinary tract), abscesses (infections containing pus),  stones and hydronephrosis (enlargement of urinary tract).  Everyone knows about the risk of Wilms tumor in BWS but fewer people understand that other non-cancerous findings are possible.  It is as important not to over-react to a positive ultrasound as it is not to under-react.

Other  recommendations for the abdominal ultrasounds include:

1. The liver should be scanned for possible hepatoblastomas.  No measurements are needed.
2. The adrenals should be checked for possible neuroblastoma or adrenal cortical carcinoma.
3. The kidneys should be measured length wise and compared to normal values for age.  Masses, cysts, stones and other abnormalities should be noted.
4. The pancreas should be evaluated and measured in A-P thickness
   Any areas of pain or discomfort should be scanned.

Finally, parents are sometimes told that their child needs a CT scan after an ultrasound.  It is important to know that sometimes an area may look suspicious on the ultrasound but turn out to be normal on the CT.  CTs are a bigger deal than ultrasound because they require an injection of contrast through a vein, they use x-rays and because younger children may need sedation.  On the other hand, when there is a suspicious area on a sonogram, the best test to do is a CT scan for either confirming or ruling out a mass.  Every once in a while your child may have to undergo a CT which turns out to be normal.  As unpleasant as this is, it is still better to be safe.

Dr. Choyke

Fasting Before Ultrasound Scans

We asked Dr Choyke to answer some questions that many parents felt confused about regarding their children needing to fast before ultrasounds. Here are the questions and below you'll find Dr Choyke's response.

1. Why exactly the fasting is required (what can't be viewed if the child has NOT fasted and why does this area need to be viewed, etc),

2. For how long the baby needs to fast prior to a scan

3. If the amount of time depends on the type of food ingested (i.e. water, breast milk vs. baby formula, juice, solid food, etc), and

4. Does age of the child affect the amount of time required for fasting?

Dr Choyke's response:

Fasting is usually recommended for two reasons:

1. The gallbladder contracts with eating and becomes unevaluable and

2. Food induces peristalisis and that introduces a lot of air into the bowel which hides some organs, mainly the pancreas but also the kidneys occasionally. These are usually not critical in BWS although the pancreas can occasionally be an issue. Still some centers have one policy for everyone and you should try to adhere to it.

For kids >1 year we generally recommend that they get an early appointment in the morning, skip breakfast but have some water or small amounts of juice and have breakfast after the US. If that is not possible we recommend at least 2 hours of no eating beforehand. For babies, breast feeding seems to be fine but bottle feedings introduce more air into the abdomen so we would wait 2 hours after the last bottle feeding. Judgment is important. If your baby is crying because they are hungry then the exam won't go well...isn't it better to be happy while you have your scan?

Dr. Choyke