Milestone-Proposal talk:The Birth of the First CT Scanner

Advocates and reviewers will post their comments below. In addition, any IEEE member can sign in with their ETHW login (different from IEEE Single Sign On) and comment on the milestone proposal's accuracy or completeness as a form of public review.

Introduction and next steps -- John Vardalas (talk) 21:29, 22 May 2020 (UTC)

Dear Proposer:

I am a member of the IEEE History Committee and I will be the Advocate for this proposal. As Advocate, my responsibility is to facilitate the submission of this proposal to a vote by the History Committee. Before I can recommend this proposal to the Committee, at least two external expert reviews are required.

We need to put together a list of possible reviewers. If you have names to recommend, please send them on to me via my email address.

I see that you have not yet checked off the box "Site Owner Permission Letter Received". Have you not yet received this letter?

John Vardalas, Ph.D.

IEEE History Committee

Christopher James review -- ProfCJJ (talk) 21:29, 8 Sept 2020 (UTC)

I am answering the questions put to me directly below. I note the review from my colleague in the filed and I agree whole heartedly with the comments therein.

1) - "What is the historical significance of the work (its technological, scientific, or social importance)?"

The significance is profound - not only was it technologically innovative to mix X-ray radiation for imaging with this automated computed platform, but it transformed the field of engineering in healthcare, opening the door for the current state of the art in healthcare technology where healthcare is now routinely monitored using computed means. It also revolutionised the provision of healthcare and how diagnosis takes place through 2D and then 3D imaging of the body.

- "What obstacles (technical, political, geographic) needed to be overcome?"

The technological obstacles would have been great, mixing X-ray radiation with computers in this way to provide diagnostics speedily and safely. Speed and safety being the paramount concerns. The 1st generation scanners created the framework for all the future generations - each refining in speed and accuracy.

- "What features set this work apart from similar achievements?"

At the time there was nothing similar - this was quite the breakthrough.

2) Your review should include responses to the following questions.

a) Have they established clear historical significance?

I do not know the full details, only from what I have read in the text books. This looks fine to me though and I believe this is well documented in the relevant literature.

b) Are their arguments technically strong?

The arguments are 'spot on'. I don't think this is something that is up to interpretation - the technical arguments are clear and convincing.

c) Do the answers adequately support the Milestone claim:''

Yes - it s clear, concise and conveys the detail of what was achieved - it correctly states that this did indeed mark the beginning of a new era in clinical medicine. The engineer went from fixing broken auxiliary equipment to creating brand new modalities that completely revolutionised healthcare.

"On October 1st 1971 Godfrey Hounsfield produced a Computerized Tomographic (CT)T scan of a patient's brain that allowed a surgeon to remove a detected cancer. The CT scanner used in this demonstration had been invented and constructed by Hounsfield at the EMI Laboratories located on their campus at this site. It was the world's first imaging system capable of producing high resolution images of internal body structures, and marked the beginning of a new era in clinical medicine."

d) In your view, is the wording of the above claim accurate?

Yes. Concise and to the point.

e) Finally have the proposers provided adequate "Supporting texts and citations to establish the dates, location, and importance of the achievement:"


3) Please feel free to express any additional views on this proposed Milestone and make any suggestions for improvement.

Nothing other than to say that as a student just about to embark on a degree in Electronic Engineering at the University of Malta, it was seeing an article on this new computed tomography scanner in National Geographic that showed me the way to the vocation I an in now - a career in biomedical engineering - that was my "Eureka" moment :)

Review from Prof. Hawkes -- John Vardalas (talk) 05:20, 3 September 2020 (UTC)

The following, which I received on 2 Sept. 2020, is Prof. Hawkes's verbatim review of the proposal.

Professor Dave Hawkes founded the Centre for Medical Image Computing (CMIC) at University College London (UCL) in 2005 and has directed it since then. He has been co-Director of the CR-UK, EPSRC and DoH funded joint UCL/KCL Comprehensive Cancer Imaging Centre since 2011. He was Chairman of the Division of Imaging Sciences at KCL between 2002 and 2004 and Director of the £8M EPSRC and MRC funded IRC in Medical Images and Signals from 2003-2007. In 2019 Prof. Hawkes was awarded the Peter Mansfield Medal and Prize by the Institute of Physics for his lifetime contribution to medical imaging research.

"It is an honour to have the opportunity to comment on the proposal to erect a Milestone Plaque at Jupiter House, the site of the old EMI headquarters. I have read the proposal and strongly support the Milestone proposal. The invention of X-ray CT revolutionised radiology and subsequently almost every branch of medicine. There are few medical conditions that do not at some stage require a “scan”.

Early in my career I had the good fortune to work with Dr. John Perry at St. George’s Hospital in South London. John was the medical physicist tasked with checking that the newly invented “EMI-Scanner” was safe to use from a radiation safety perspective. He is the first author of the third of the three landmark papers on the new scanner, published in the British Journal of Radiology in 1973. He had a series of amusing anecdotes of the work he did with Jamie Ambrose, the neuroradiologist at Atkinson Morley Hospital, and Godfrey Hounsfield himself. The initial investment in the project arose from the large sum earned by EMI on the production of the compilation of the Beatles’ songs a year or so earlier. Godfrey Hounsfield, who’s experience was mainly in radar and defence electronics, applied internally within EMI for access to some of these funds to develop the first scanner.

John also spoke of the fortuitous link between Jamie Ambrose and Godfrey Hounsfield and their determination to create a clinically usable system. Godfrey Hounsfield had no medical experience and his early approaches to the established medical engineering industry had been rebuffed. His letter from a well-known medical engineering company, turning down his invention as “having no practical medical application”, was subsequently framed and hung in his office. Jamie Ambrose saw the potential and together they persevered with the first clinical installation at Atkinson Morley Hospital, later to become part of St. George’s Hospital.

The computer used to collect the data on the first clinical scans was not powerful enough to do the reconstructions so the data was stored on magnetic tape and driven to the EMI research labs in Hayes, West London. The reconstructed image data were sent back the next day. There was no screen capable of displaying the images at that time so the integer numerical data was printed out on large format computer paper. Attenuation numbers close to water had short numbers close to zero, bone and lesions within the skull had larger and hence longer numbers. By pinning the print out to the wall and stepping back it was possible to see the bone outline and a lesion (long numbers and appearing darker) within the brain (short numbers and appearing lighter).

I myself met Godfrey Hounsfield a few years later when I set up my lab at Guy’s Hospital. He always maintained an interest in using his CT images to guide surgery and we were developing a project at the time in augmented reality, overlaying CT and MRI renderings in a surgical operating microscope. We visited his facilities at Hayes and he regularly attended our weekly seminars. He was a shy and modest man and always crept in at the back once the talks had started, but asked probing questions at the end. The students enjoyed having him visit.

I have a couple of very minor comments:

Can I suggest inserting the words “clinical” and “X-ray” before “CT” in the title and before “Computerized Tomography” in the Milestone Claim. This distinguishes his work from earlier tomographic reconstruction methods, for example that of Cormack. Godfrey Hounsfield’s major contribution was construction of a clinically usable X-ray CT system that was installed in a hospital and used to generate images on patients. Ultrasound had also been shown to produce images of internal anatomy, but not of the head and not at the detail that X-ray CT could achieve.

I would re-phrase “..that allowed a surgeon to remove a detected cancer” as “.. that allowed a radiologist to locate a cancer and hence guide a surgeon in its removal”. While I am sure it was used by surgeons the initial published work was with a neuroradiologist, Jamie Ambrose.

In the section: “What features set this work apart from similar achievements?” I would rephrase as: “The EMI CT Scanner was the first clinical machine capable of producing high resolution images of X-ray attenuation, allowing depiction of the internal structures and organs of the human body.” MRI is a completely different imaging modality and although it does produce very high quality images, without delivering a dose of ionising radiation, X-ray CT remains the modality of choice for many investigations in for example the lung, vascular systems and the heart etc.

I think it would be appropriate to cite Godfrey Hounsfield’s landmark paper in the British Journal of Radiology. This describes the system.

Computerized transverse axial scanning (tomography): Part 1. Description of system G.N. Hounsfield, 1973, British Journal of Radiology, 46, 1016-1022"

Professor David Hawkes, FMedSci, FREng, FInstP Wellcome/EPSRC Centre for Interventional and Surgical Sciences University College London Charles Bell House 43-45 Foley Street, London, W1W 7TS

possible citation editing -- Amy Bix (talk) 02:29, 1 October 2020 (UTC)

The current citation seems a bit wordy to me and unfocused. I also wonder why choosing the 1971 "exhibit" date, rather than the 1972 patent date? (at least I see a 1972 patent date on the Nobel Prize webpage - someone should check this....)(this then raises the question of what the 1967-1975 timeframe in the title means....) Some thoughts for possible rewriting?:

At the EMI Laboratories on this site, Godfrey Hounsfield invented the world’s first clinical X-ray Computerized Tomography scanner, patented in 1972. This medical device safely and rapidly generated high-resolution images that advanced diagnostics, therapy, and research of brain tumors and other diseases. This Nobel Prize-winning breakthrough opened a new era in medical technology, advancing precision monitoring of internal health.

Re: possible citation editing -- Jason.k.hui (talk) 16:14, 4 October 2020 (UTC)

Milestones honor the achievement, rather than a place or a person. Does Sir Hounsfield need to be identified in the citation? Also, the Nobel Prize that he won in developing X-ray computer assisted tomography was shared with Allan MacLeod Cormack. The October 1971 date refers to when the first patient brain-scan was conducted on a patient at Atkinson Morley's Hospital in Wimbledon, London, UK. I agree with Amy on decoupling that event with the actual date of invention.

Re: Re: possible citation editing -- Jbart64 (talk) 00:14, 7 October 2020 (UTC)

I agree with the comments above, names are not included in Milestones unless part of a proper noun and title. I suggest modifying to drop the names and Nobel Prize reference:

A team at the EMI Laboratories on this site invented the world’s first clinical X-ray Computerized Tomography scanner, patented in 1972. This medical device safely and rapidly generated high-resolution images that advanced diagnostics, therapy, and research of brain tumors and other diseases. This breakthrough opened a new era in medical technology, advancing precision monitoring of internal health.

David Bart

History Committee proposes changes in the wording of the citation -- John Vardalas (talk) 04:46, 10 October 2020 (UTC)

The History Committee met on 7 October to discuss this proposal. A vote on it was postponed until the 3 November meeting. The merits of a Milestone for the CT Scan were never in question. However, members of the Committee did feel that revisions in the citation were needed. They suggested the following citation as a starting point towards a final version of the citation.

"EMI Laboratories on this site created the world’s first clinical X-ray Computerized Tomography scanner. This medical device safely and rapidly generated high-resolution images that advanced diagnostics, therapy, and research of brain tumors and other diseases. This breakthrough opened a new era in medical technology, advancing precision monitoring of internal health."

The 1972 patent date was left out because an ambiguity in dates arises from the title. Nowhere in the body of the proposal is there an explanation as to why "1967 - 1975". Am I correct in stating that Hounsfield came up with the idea in 1967, filed for a patent in 1968, did the first clinical test in 1971, and was granted a patent in 1972? Why then single out the 1972 date? There is also the question as to why the year 1975 appears in the title. The reference to the Nobel Prize was also dropped from the Committee's version. Reference to the Nobel Prize should be part of the body of the proposal where the evidence is presented.

If you prefer not using proposal's Discussion page, I will gladly post your comments. I believe that we are close to approval. All that remains is a mutually acceptable wording of the citation.

last phrase of the citation -- Juan Carlos (talk) 22:10, 28 November 2020 (UTC)

I think this really deserves a Milestone. I like the wordin of Amy,but what does "internal health mean? CThelps to study and diagnose Organs....

citation suggestions -- Lise Johnston (talk) 16:18, 8 January 2021 (UTC)

I suggest removing First from the citation total. If its the birth of then its obviously the first. "The Birth of the CT Scanner" is stronger.

Please remove the name of the individual as the general practice of the Milestone process is to not award a milestone that appears to be going to an individual except as needed to explain the achievement ie. "Maxwell's Equations"

I don't mind the reference to the Nobel Prize but it would be useful to say in what field it was awarded.