{
  "patent_number": "US 3778614",
  "country": "US",
  "title": "How Early CT Scans Created Detailed Body Images",
  "original_title": "Method and apparatus for measuring x- or {65 -radiation absorption or transmission at plural angles and analyzing the data",
  "summary": "This 1973 patent describes a method for using X-rays from many angles to build a detailed 2D image of the inside of a body, like a slice of a CT scan.",
  "what_it_does": "This patent details a method for creating a 2D image of a body slice using penetrating radiation, like X-rays. Radiation is sent through the body from many different angles, passing through many paths. Each path's 'transmission' (how much radiation gets through) is measured. The patent claims a way to use these measurements, especially by 'successive approximations' where calculations are repeatedly refined, to figure out the absorption or transmission of tiny, individual elements within the body's 2D matrix. These refined values are then used to create a visual representation, like on a screen or photo, showing the internal structure. For example, imagine shining X-rays through a slice of your arm from the front, then the side, then diagonally, and using those readings to map out the density of bone versus muscle in each tiny spot.",
  "what_it_does_not_cover": [
    "Methods that only use radiation from a single angle.",
    "Imaging techniques that don't involve measuring radiation transmission or absorption.",
    "Creating 3D images instead of 2D slices.",
    "Methods that don't use a 'successive approximation' process to calculate internal element values.",
    "Using radiation sources other than X-rays or gamma rays."
  ],
  "filed": "1971-12-27",
  "granted": "1973-12-11",
  "expires": "1991-12-27",
  "status": "expired",
  "holder": "EMI Ltd",
  "holder_url": "https://patentbrief.org/company/emi-ltd",
  "inventors": [
    {
      "name": "Hounsfield G Newbold",
      "url": "https://patentbrief.org/inventor/hounsfield-g-newbold"
    }
  ],
  "times_cited": 163,
  "tags": [
    "biotech",
    "medical_devices",
    "semiconductors"
  ],
  "abstract": "In apparatus for examining a body by means of X or Y radiation, a two-dimensional matrix of elements of the body is exposed to radiation from a number of directions and the transmission of the radiation by a plurality of paths of small cross-sectional area through the body is measured, the directions and numbers of the paths being such that each element of the matrix is intersected by a group of paths which intersect different groups of elements. From these measurements, the absorptions or transmissions in of the individual elements of the matrix are calculated and used to produce a cathode ray tube display and/or a photograph.",
  "url": "https://patentbrief.org/patent/us/3778614/ct-scanner-hounsfield",
  "markdown_url": "https://patentbrief.org/patent/us/3778614/ct-scanner-hounsfield/md",
  "google_patents_url": "https://patents.google.com/patent/US3778614",
  "relatedPatents": [
    {
      "patentNumber": "3789832",
      "countryCode": "US",
      "title": "Using Nuclear Magnetic Resonance to Detect Cancer in Tissue",
      "url": "https://patentbrief.org/patent/us/3789832/mri-magnetic-resonance-imaging"
    },
    {
      "patentNumber": "4195637",
      "countryCode": "US",
      "title": "Catheter System for Opening and Closing Body Passages",
      "url": "https://patentbrief.org/patent/us/4195637/balloon-angioplasty-catheter-gruentzig"
    },
    {
      "patentNumber": "3867571",
      "countryCode": "US",
      "title": "How Laser Printers Use Rotating Mirrors to Write Information",
      "url": "https://patentbrief.org/patent/us/3867571/laser-printer-starkweather"
    },
    {
      "patentNumber": "4131919",
      "countryCode": "US",
      "title": "The First Digital Camera's Core Technology",
      "url": "https://patentbrief.org/patent/us/4131919/digital-camera-electronic-still"
    },
    {
      "patentNumber": "4665913",
      "countryCode": "US",
      "title": "How Lasers Correct Vision by Reshaping the Eye's Front Surface",
      "url": "https://patentbrief.org/patent/us/4665913/laser-eye-surgery-lesperance"
    }
  ]
}