Role in development of neuroimaging In 1959, Oldendorf conceived an idea for "scanning a head through a transmitted beam of
X-rays, and being able to reconstruct the radiodensity patterns of a plane through the head" by watching an engineer who was working on an automated apparatus to reject frostbitten fruit by detecting dehydrated portions. Not until 1961 did he complete a working prototype of his idea, apply (for $1700) for a patent on his idea, and publish an article detailing the work. Ingeniously, by using materials found in his home (such as his son's toy train, a phonograph turntable, and an alarm clock motor), Oldendorf demonstrated a method of producing cross-sectional images of soft tissue by
back-projection and reconstruction. In his landmark paper, also published in 1961, he described the basic concept later used by
Allan McLeod Cormack to develop the mathematics behind computerized tomography, though Prof. Cormack was unaware of Oldendorf's work. In October, 1963 Oldendorf finally received a U.S.
patent for a "
radiant energy apparatus for investigating selected areas of interior objects obscured by dense material,". This work was recognized by
Godfrey Hounsfield as the only other attempt at
tomographic reconstruction, and, indeed, formed the basis of much of his Nobel prize-winning work. The prototype developed by Dr. Oldendorf, however, did not lead to the development of the first industrial
CAT scanning device. When suggested to a leading X-ray manufacturer of the time, the president of the company retorted, Faced with this reaction, Oldendorf "turned his attention to other scientific work and heard nothing further about the idea until 1972." However, his idea was a fundamental discovery which also led to
MRI,
positron emission tomography (PET), single photon emission computed tomography (
SPECT), and other imaging techniques. Once these techniques became widely accepted, Dr. Oldendorf, along with
William Markley McKinney, MD (1930–2003) were instrumental in promoting the use of
Computed Tomography among neurologists to help decrease the use of superfluous and invasive tests.
Blood–brain barrier Oldendorf made many other discoveries that have significantly affected
neuroscience and the practice of
medicine. He developed an original method to analyze blood flow in the brain and the
kinetics of blood-brain permeability. The idea of the blood–brain barrier was already entrenched in medical science by this time, but had never been quantified. Oldendorf's work in measuring blood flow with
radioactive isotopes was fundamental to the subsequent development of techniques now used in many nuclear medicine laboratories. His methods of assessing blood–brain barrier permeability increased knowledge of the mechanisms whereby
drugs and metabolic substrates enter into the brain. Especially important was his characterization of more than a dozen independent carrier systems, along with their saturation kinetics. Today, most of what is known of the selective permeability of the blood–brain barrier was either established by Oldendorf in his laboratory, or by others using his ingenious techniques. These results have been essential in developing PET and SPECT imaging; in studying
glucose transport and brain metabolism; and in characterizing clinically important diseases such as
cerebral ischemia,
starvation, and
epilepsy. Oldendorf's experiments were also the first to prove that
cerebrospinal fluid functions as a "sink" in relationship to brain metabolism, a concept that is being investigated in relation to the
pathophysiology of presenile dementias such as
Alzheimer's disease.
Professional publications and societies In his lifetime, Oldendorf wrote three textbooks and over 250 scientific articles, including
The Quest for an Image of the Brain: Computerized Tomography in the Perspective of Past and Future Imaging Methods (Raven Press, New York, 1980) and
Basics of Magnetic Resonance Imaging (Kluwer Academic Press, Boston, 1988). The book
Basics of Magnetic Resonance Imaging is notable for being co-authored with his son and
namesake, William Oldendorf, Jr. Oldendorf was one of the 30 attendees of the Neurology Computed Tomography Symposium, organized by William Kinkel from September 24 to September 25, 1975, in
Buffalo, New York. He participated in the
ad hoc committee that unanimously voted to form the Society for Computerized Tomography so as to continue its educational activities. Realizing that other imaging modalities may eventually be prominent, the following year Oldendorf pushed to have the name of the society changed to Society for Computerized Tomography and Neuroimaging, and served as its president from 1978 to 1979. This society was to rename itself the
American Society for Neuroimaging (ASN) in 1981, also with the prodding of Oldendorf. Oldendorf was on several editorial boards and was a Fellow of the
American Academy of Arts and Sciences. In 1992, he became the first neurologist ever to be elected to the
National Academy of Sciences. == Awards and prizes ==