History of neuroimaging

[5] The brain is almost entirely composed of soft tissue that is not radio-opaque, meaning it remains essentially invisible to ordinary or plain X-ray examinations.

[citation needed] Introduced in 1927, cerebral angiography enabled doctors to accurately detect and diagnose anomalies in the brain such as tumors and internal carotid artery occlusions.

Over the course of a year, Egas Moniz, the inventor of cerebral angiography, ran experiments with various dye solution percentages that were injected into arteries to help better visualize the blood vessels in the brain before discovering that a solution consisting of 25% sodium iodide was the safest for patients, as well as the most effective in the visualization of blood vessels and arteries within the brain.

[11] Magnetoencephalography (MEG) is a technique that looks for regions of activity in the brain by detecting large groups of electrically charged ions moving through cells.

[13] In order to be noninvasive, the MEG was designed like a giant helmet that the patient would put their head inside of and, once turned on, would read the electromagnetic pulses coming from their brain.

Later on, in 1972, Cohen invented the SQUID (superconducting quantum interference device), which gave the MEG the ability to detect extremely small changes in ions and magnetic fields in the brain.

Although many trial scans and tests were ran during the development process of computed tomography, British biomedical engineer Godfrey Hounsfield is the founder of the technique and invented the first CT scanner in 1967, which he won a Nobel Prize for in 1979.

Rather than using ionizing or X-radiation, MRI uses the variation in signals produced by protons in the body when the head is placed in a strong magnetic field.

Associated with early application of the basic technique to the human body are the names of Jackson (in 1968), Damadian (in 1972), and Abe and Paul Lauterbur (in 1973).

During the 1980s a veritable explosion of technical refinements and diagnostic MR applications took place, enabling even neurological tyros to diagnose brain pathology that would have been elusive or incapable of demonstration in a living person only a decade or two earlier.