Then he moved on, spending a few years in neuroradiology, where he made a special chair for injecting air into the spinal space to fill the brain's ventricles and ease the diagnosis of tumors, a technique known as pneumoencephalography.
12.
Historically lumbar punctures were also employed in the process of performing a pneumoencephalography, a nowadays obsolete X-ray imaging study of the brain that was performed extensively from the 1920s until the advent of modern non-invasive neuroimaging techniques such as plain radiographs.
