Page 26 - July Impression

Early Neuroimaging

Pneumoencephalography may seem like a
crazy word from a sadistic spelling bee, but it

is actually a type of imaging utilized before the
time of CT and MRI.
Introduced in 1919, the imaging technique

involved a lumbar puncture and the removal
of a small amount of cerebrospinal fluid. Then
air, oxygen, or even helium was injected in
small increments to take the place of the
removed CSF.
After the injection, the patient would be need
to be moved around to allow the air to travel
along the surface and ventricles of the brain.

This allowed for better visualization of the
structures of the brain. While it helped to the procedure prevented it from being rapidly
identify tumors and other gross abnormalities, adopted. Over time though, evolving techniques
such as hydrocephalus, the technique was helped to reduce patient discomfort and improve
quite cumbersome overall. the diagnostic quality of the imaging performed.
This led to greater acceptance of
As one could imagine, this type of imaging had pneumoencephalography.
a few side effects such as headaches, and
severe vomiting. Overall, patients did not The last major advance in this imaging technique
normally tolerate these exams very well. These was the development of 360° rotating chairs.
side effects, along with the invasive nature of This tool offered a means to securely fasten the
patient to the chair while it was rotated. This
allowed for a greater movement of the air or gas
introduced and more complete filling of the
ventricles of the brain.
The advent of the EMI Scanner (CT) in the early
1970’s would represent a quantum leap in the
neuroradiologic evaluation of patients. As a
result, pneumoencephalography would slowly

become obsolete.
Looking back, pneumoencephalography seems
savage in comparison to the quick and non-

invasive imaging techniques we use today.