Godfrey Newbold Hounsfield, who revolutionized neuroimaging(annalsofian.org)
annalsofian.org
Godfrey Newbold Hounsfield, who revolutionized neuroimaging
https://www.annalsofian.org/article.asp?issn=0972-2327;year=2016;volume=19;issue=4;spage=448;epage=450;aulast=Bhattacharyya
36 comments
Oldendorf and Damadian (MRI) are great examples of Nobel blunders -- my money is on Takahashi for his significant contributions:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3258406/
Steve Webb wrote an excellent book that traces the origins of radiological tomography:
https://www.amazon.com/Watching-Shadows-Origins-Radiological...
These are some notes of mine for a presentation on the subject (relative to radiotherapy): https://drive.google.com/file/d/1-2VAFzmkGu25YJM_QFLDiUB9vRv...
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3258406/
Steve Webb wrote an excellent book that traces the origins of radiological tomography:
https://www.amazon.com/Watching-Shadows-Origins-Radiological...
These are some notes of mine for a presentation on the subject (relative to radiotherapy): https://drive.google.com/file/d/1-2VAFzmkGu25YJM_QFLDiUB9vRv...
> Finally, in possibly his most ingenious invention, Hounsfield created an algorithm to reconstruct an image of the brain based on all these layers. By working backward and using one of the era’s fastest new computers, he could calculate the value for each little box of each brain layer. Eureka!
And, of course, they glossed over the most interesting part by simply saying "an algorithm." I know that modern CT scans use Marching Cubes [1], which is what that particular algorithm was developed for, but that came later in the 80s.
[1] https://en.wikipedia.org/wiki/Marching_cubes
And, of course, they glossed over the most interesting part by simply saying "an algorithm." I know that modern CT scans use Marching Cubes [1], which is what that particular algorithm was developed for, but that came later in the 80s.
[1] https://en.wikipedia.org/wiki/Marching_cubes
Marching Cubes is only the visualization mechanism after you have the voxels. The real work is in reconstructing the 3D data [voxels] from 1D scans, and that typically uses the Radon transform:
https://en.wikipedia.org/wiki/Radon_transform
https://en.wikipedia.org/wiki/Radon_transform
Don't they really use Feldkamp-Davis-Kress cone-beam algorithm? (https://pubmed.ncbi.nlm.nih.gov/15305448/)
Because the x-ray sources are point sources, or close, so you get a cone beam.
Because the x-ray sources are point sources, or close, so you get a cone beam.
There’s a large amount of different reconstruction algorithms, some geared for speed, some geared for noisy data, some geared for quality.
Wikipedia has a quick overview: https://en.wikipedia.org/wiki/Tomographic_reconstruction
Later, that was developed in 1984; CT's use collimated fan beams
Use? You mean currently? I thought they used cone beams, but I never worked on them directly...
A fan beam is ‘just’ a more collimated cone beam.
Yes, but this was only shown later -- The reconstruction algorithm for cone-beam was published in 1984 by research staff at Ford Motor Company. The Felkamp, Davis, and Kress algorithm was demonstrated as a natural extension of the fan-beam algorithm. -- first pencil beam, then fan-beam, finally cone-beam
I don’t think they glossed over the marching cubes algorithm, but more over the theoretical work of Allan Cormack [0], which is crucial for CT reconstruction.
(I work with (benchtop) microCT machines)
[0]: https://en.wikipedia.org/wiki/Allan_MacLeod_Cormack
(I work with (benchtop) microCT machines)
[0]: https://en.wikipedia.org/wiki/Allan_MacLeod_Cormack
Wow, I didn't know there was such a thing. What do you image with them?
Mostly biomedical samples. Recently a bunch of human teeth [1] or a few heads of zebrafishes [2].
I mostly deal with the data acquisition and then the image processing of the acquired tomographic data.
[1]: https://habi.github.io/zmk-tooth-cohort-method-manuscript/
[2]: https://doi.org/10.1371/journal.pone.0228333
[1]: https://habi.github.io/zmk-tooth-cohort-method-manuscript/
[2]: https://doi.org/10.1371/journal.pone.0228333
I was taught in school that the algorithm was an inverted 3d Fourier Transform. I'm not sure if I believe that now.
As I remember, Hounsfield originally used a much worse algorithm than that, although it was still workable and let him build usable machines. Later ones were more efficient due to using better math, but Hounsfield's got the job done.
> Hounsfield pondered whether it was possible to detect hidden areas in Egyptian pyramids by capturing cosmic rays that passed through unseen voids.
I also wondered about this possibility a few years ago and when I searched online, I found an example of muon tomography of the volcanic dome of La Soufrière on the island of Guadeloupe[1]. Cool non-seismic approach to a difficult imaging problem.
Specifically, I was wondering about neutrino tomography of the entire earth, but the low probability of neutrino collisions would seem to make that infeasible.
[1] https://www.youtube.com/watch?v=CPYhqJ3e-2o
I also wondered about this possibility a few years ago and when I searched online, I found an example of muon tomography of the volcanic dome of La Soufrière on the island of Guadeloupe[1]. Cool non-seismic approach to a difficult imaging problem.
Specifically, I was wondering about neutrino tomography of the entire earth, but the low probability of neutrino collisions would seem to make that infeasible.
[1] https://www.youtube.com/watch?v=CPYhqJ3e-2o
A team from Berkeley led by Luis Alvarez used Cosmic Rays to image the inside of the Great Pyramid in the 1960's[0]. tl;dr it's solid rock. My favorite story from the effort was they briefly had incredible excitement because they found a chamber. The excitement lasted until they realized they had neglected to include the room where the detectors were located, which the system detected correctly, in their analytical model of the structure (providing their method was able to identify unpredicted rooms in the structure).
[0]https://www.science.org/doi/abs/10.1126/science.167.3919.832
[0]https://www.science.org/doi/abs/10.1126/science.167.3919.832
I'm more impressed by how you would align the X rays slices to correct translation / shifts, seems like a bigger problem to me than reconstructing the data from aligned scans
You're on the money with this one. Accurate table translations was an important enabling technology - same with slip-rings for full rotation
He wasn't the only "eccentric engineer" associated with the Beatles and Apple: https://en.wikipedia.org/wiki/Magic_Alex
I thought the "nothing box" that he invented was an apt self-description.
Wound up finding an old advert for it: http://lennonsunroom.blogspot.com/2010/04/nothing-box.html
Wound up finding an old advert for it: http://lennonsunroom.blogspot.com/2010/04/nothing-box.html
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It's unfortunate that he went back to work instead of quitting and filing patents on the device.
This article title is rather poor: while the Beatles recorded some records for EMI, they founded a record company (Apple Records) and did much of their work under that label, so "the Beatles' record company" would in context always refer to Apple, not EMI.
The focus of the article is to make it seem random that this guy was working for a record company that distributed the Beatles and yet he invented X-Ray CT scans.
His biography on Wikipedia[1] which dovetails with the true history of EMI, at one time a builder of computers and other electronics, makes it more a matter of the inspiration from a walk in the countryside coming into the mind of a well-prepared engineer.
[1] https://en.wikipedia.org/wiki/Godfrey_Hounsfield
His biography on Wikipedia[1] which dovetails with the true history of EMI, at one time a builder of computers and other electronics, makes it more a matter of the inspiration from a walk in the countryside coming into the mind of a well-prepared engineer.
[1] https://en.wikipedia.org/wiki/Godfrey_Hounsfield
He retired from EMI in 1986 and used the prize money from his Nobel to build a personal laboratory in his home.
Loved that part. Imagine a $1M home lab!
Loved that part. Imagine a $1M home lab!
So a trained engineer who won the Nobel prize. What an egregiously clickbait-y title.
He won the Nobel for the invention of the CT scan. The clickbait-y part mostly concerns EMI. EMI is strange company. It started as a merger between a gramophone producer and a record company to create a vertically integrated business in the 30s. Capitalising on their expertise in sound production and broadcasting equipments they became a very important producer of radar equipments during the Second World War. And it’s this expertise in military radar technology which lead to the development of the CT scan. Meanwhile the recording part of the company merrily lived its own life and happened to produce the Beatles.
I agree, describing EMI as "the Beatles record company" is true but very misleading.
EMI was a diverse conglomerate that was involved in all kinds of stuff, from military RADAR systems to making TV cameras, computers and blank cassette tapes. Yes, EMI had a record company division (also famous for firing The Sex Pistols), but EMI was exactly the kind of huge industrial tech company you would expect to invent a new kind of scanner.
EMI was a diverse conglomerate that was involved in all kinds of stuff, from military RADAR systems to making TV cameras, computers and blank cassette tapes. Yes, EMI had a record company division (also famous for firing The Sex Pistols), but EMI was exactly the kind of huge industrial tech company you would expect to invent a new kind of scanner.
Yesterday was the 50th anniversary of the first CT scan!
https://twitter.com/ARRS_Radiology/status/144391762570111388...
https://www.youtube.com/watch?v=u_R47LDdlZM
https://twitter.com/ARRS_Radiology/status/144391762570111388...
https://www.youtube.com/watch?v=u_R47LDdlZM
He used a record turntable and a toy train to prototype his early ideas.
His egregious exclusion from the Nobel prize was deemed a political decision by the Europeans committee due to ongoing patent matters.
Edit: For anyone interested in medical tomography, check out the current cutting edge, a bedside(!) MRI using two huge rare earth magnets[2].
[0]https://en.wikipedia.org/wiki/William_H._Oldendorf#Role_in_d...
[1]https://en.wikipedia.org/wiki/History_of_computed_tomography
[2]https://hyperfine.io