A scene from The Exorcist, in which Regan undergoes pneumoencephalography.

How did neuroradiologists image the brain before the invention of computed tomography and magnetic resonance imaging? They used a form of torture called pneumoencephalography. Perhaps the greatest contribution of CT and MRI-both discussed in Intermediate Physics for Medicine and Biology-was to make pneumoencephalography obsolete.

In their article “ Evolution of Diagnostic Neuroradiology from 1904 to 1999,” ( Radiology, Volume 217, Pages 309–318, 2000), Norman Leeds and Stephen Kieffer describe this odious procedure.

Pneumoencephalography was performed by successively injecting small volumes of air via lumbar puncture and then removing small volumes ofcerebrospinalfluid with the patient sitting upright and the head flexed… Pneumoencephalography was used primarily to determine the presence and extent ofposterior fossa or cerebellopontine angle tumors, pituitary tumors, and intraventricular masses… It was also used to rule out the presence of lesions affecting the cerebrospinal fluid spaces in patients with possible communicatinghydrocephalus ordementia… After the injection of a sufficient quantity of air, the patient was rotated, somersaulted, or placed in adecubitus position to depict the entire ventricularsystem and subarachnoid spaces. These patients were often uncomfortable, developed severe headaches, and became nauseated or vomited.

In Chapter 7 of the book Radiology 101: The Basics and Fundamentals, Wilbur Smith shares this lurid tale.

The early brain imaging techniques… involved such gruesome activities as injecting air into the spinal canal (pneumoencephalography) and rolling the patient about in a specially devised torture chair. Few patients willingly returned for another one of those examinations!

In her book The Immortal Life of Henrietta Lacks, Rebecca Skloot writes

I later learned that while Elsie was at Crownsville, scientists often conducted research on patients there without consent, including one study titled “Pneumoencephalographic and skull X-ray studies in 100 epileptics.” Pneumoencephalography was a technique developed in 1919 for taking images of the brain, which floats in a sea of liquid. That fluid protects the brain from damage, but makes it very difficult to X-ray, since images taken through fluid are cloudy. Pneumoencephalography involved drilling holes into the skulls of research subjects, draining the fluid surrounding their brains, and pumping air or helium into the skull in place of the fluid to allow crisp X-rays of the brain through the skull. the side effects-crippling headaches, dizziness, seizures, vomiting-lasted until the body naturally refilled the skull with spinal fluid, which usually took two to three months. Because pneumoencephalography could cause permanent brain damage and paralysis, it was abandoned in the 1970s.

Russ Hobbie claims that the development of CT deserved the Nobel Peace Prize in addition to the Nobel Prize in Physiology or Medicine!

The application of physics to medicine and biology isn’t just to diagnose diseases that couldn’t be diagnosed before. It also can help replace barbaric procedures by ones that are more humane.

Originally published at



Professor of Physics at Oakland University and coauthor of the textbook Intermediate Physics for Medicine and Biology.

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Brad Roth

Professor of Physics at Oakland University and coauthor of the textbook Intermediate Physics for Medicine and Biology.