kids’ korner
Imaging in Children with Headaches
Howard S. Jacobs, MD
Associate Professor of Pediatrics
Co-Director, Pediatric Headache Clinic
University of Maryland Medical Center
Baltimore, Maryland
“Dr. Jacobs, don’t you think my
daughter should have a CT scan
to check out her headaches?”
I have heard that statement, or one like it, hundreds of
times as I evaluate a child with headaches. Every parent of
a child suffering with headaches is worried that their child
has a brain tumor. But is imaging really a good idea?
Not too long ago, these wonderful imaging studies were
not available. Until the late 1970s, before the advent of
computerized tomography or CT, the only way to image
the brain was to perform a pneumo-encephalogram—an
unpleasant and potentially dangerous test that involved
injecting air into the cerebro-spinal fluid (CSF) and
allowing it to elevate into the ventricles of the brain. The
four ventricles are open spaces in the brain that contain
CSF. Once the air moved into the ventricles, it provided a
contrast which could be observed on an X-ray.
With the advent of the CT scan, imaging became
relatively safe and easy to demonstrate most of the brain
“Most” is a very important term here because there are
parts of the brain that a CT scan does not asess well—but
more on that later. During the late 1970s and early 1980s,
CT scans revolutionized our ability to image brain tissue.
Initially, CT scans were slow tests, but which can now
be done relatively quickly. However, they do have some
drawbacks. Because of the bone in the posterior part of
the skull, it is difficult to image the areas in the back of
the brain, including the medulla, the cerebellum, and the
brain stem. Unfortunately, this area is often the location
where childhood tumors reside. Also, a large amount of
radiation is associated with the procedure.
During the 1990s, a new technology was developed,
magnetic resonance imaging (MRI). An MRI scan uses
no radiation and is not affected by the boney structures of
the skull. As such, MRI produces a much better image of
the posterior brain structures. Its limitations include:
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