Hydrocephalus is diagnosed by a neurological exam and imaging techniques such as an ultrasound, CT scan, MRI, Fetal MRI (also referred to as Fast MRI, and is used on a pregnant woman who is carrying a child diagnosed with hydrocephalus) – and on occasion, a pressure-monitoring system. A doctor will order the appropriate tests according to the patient’s physical exam, and also based on the patient’s age, and the suspected abnormalities of the brain.
An ultrasound may be used on a pregnant woman who has had her child diagnosed with hydrocephalus. The doctor may order a Fast MRI (there are not many of these machines around the country, as they are fairly new). The Fast MRI will assist the physician to get a better look at the baby’s brain.
A CT scan is fairly quick, easy and a good way to diagnose hydrocephalus. A CT does involve a small amount of radiation. In some cases, it may not be adequate enough to detect some of the causes of hydrocephalus.
An MRI takes longer to perform (and it may require sedation for some infants and small children). For those who are claustrophobic, a mild sedative may be given. This test can be very helpful in those cases where the cause of hydrocephalus is in doubt, or if there are other abnormalities of the brain. It can show where the blockage has occurred, and, for some, it can help determine if the patient is a candidate for an Endoscopic Third Ventriculostomy.
The Radiologist will look at the results of the scans, write a report and send the scans and report on to the doctor. The doctor, in diagnosing the type of hydrocephalus present, will utilize these reports. Depending on the type of hydrocephalus diagnosed, additional tests may be required. This is especially common in the case with someone who has been diagnosed with Normal Pressure Hydrocephalus. A lumbar tap may be ordered by the doctor to help decide whether or not normal pressure hydrocephalus is present. However, do remember that the doctor will discuss with you the tests he/she has ordered, how they are performed, and why they are necessary.