CT scan for large headed child

Dear Ask The Doctor: I have a 8 month old child who's head size if off the charts. Her height and wieght are both in the 95th and 99th percentiles. She is developing normally but the pediatrician would like to do a CT scan of her head. I understand growth charts were updaed in 2006 and that head sizes were reduced. My other children, all boys, also had large heads. I don't feel the CT is required but the doctor does. I suggested an ultrasound but the doctor claims that can't be done at this age.

Dear Greg: An exponentially growing head circumference can be concerning and needs to be evaluated. Conditions like hydrocephalus ie water in the brain need to be ruled out and also need to find out the cause of the same if it is present. Typically an ultrasound can be done through the anterior fontanelle ( soft spot) if it is still open which is possible at this age but wont give us a clear picture. I would err on the side of caution and get a CT done unless your childs head circumference has been in the upper percentiles since the begining. I hope this helps.