computed tomography
Let an agent explain computed tomography, relay principles, history, clinical and industrial uses, radiation and contrast safety from radiology and medical physics sources in general terms, describe the named forms, and distinguish CT from MRI, plain radiography, PET and ultrasound, without advising on individual scans.
Research draft, second pass
A second pass drafted this model: the structure a model of this thing needs, and what is known about it in the world. The line under this one says how the second half was obtained - researched against sources, or recalled without web access, in which case nothing here was read anywhere and every claim is a lead to verify. Unreviewed either way.
written by Claude from model knowledge without web access - no source was read, every claim is a lead to verify
Researched by: Claude
Purpose and description
Let an agent explain computed tomography, relay principles, history, clinical and industrial uses, radiation and contrast safety from radiology and medical physics sources in general terms, describe the named forms, and distinguish CT from MRI, plain radiography, PET and ultrasound, without advising on individual scans.
A medical imaging technique that uses X-rays taken from many angles and computer reconstruction to create cross-sectional images of the body, invented by Godfrey Hounsfield and Allan Cormack, who shared the 1979 Nobel Prize, with the first clinical scan in 1971, and forms the registry aliases name such as high-resolution CT of the lungs, cardiac CT, electron beam CT, CT myelography with contrast in the spinal canal, CT arthrography of joints and industrial X-ray CT measurement for non-destructive testing; CT delivers higher radiation doses than plain X-rays, so justification and dose optimisation follow principles such as ALARA, and iodinated contrast can cause allergic or kidney reactions. Decisions about scans are made with clinicians.
What it is for: Cross-sectional imaging for diagnosis and inspection.
It can be explain principles and history; relay clinical and industrial uses; describe named forms; relay radiation and contrast safety.
Distinguishing features
Cross-sectional X-ray images
Fast scanning
Radiation dose
Contrast use
What it looks like
A ring-shaped scanner with a moving table; images as grey-scale slices.
Physical character
first clinical CT scan: 1971 year - Atkinson Morley Hospital, London
Nobel Prize: 1979 year - Hounsfield and Cormack
Hounsfield scale: water 0, air -1000 note - HU
How it is recognised
X-ray cross-sectional imaging
Computed tomography of the heart, high-resolution CT, electron beam CT, CT myelography, X-ray computed tomography measurement, CT arthrography
MRI uses magnetic fields; plain radiography gives single projections; PET images tracer uptake; ultrasound uses sound waves
Related models
is a kind of - in registry terms
was invented by -
is contrasted with -
uses - in some scans
In practice
Families and kinds
diagnostic CT
CT angiography and cardiac CT
high-resolution chest CT
CT with contrast procedures
industrial CT
Standards and regulation
Radiation protection regulations such as IRMER and EU BSS Directive
Diagnostic reference levels
Appropriateness criteria for imaging
Failure modes and hazards
Unnecessary radiation exposure
Contrast reactions
Advising on individual scans
Also called
Where this came from
wikidata · CC0 1.0
Drafted structure
Bundle to layer to finding to question, as the second pass will find it: 4 bundles · 8 layers · 8 findings · 16 questions.
Understand What CT is.
Science.
Definition
Definition.
Definition
Definition.
- Has someone developed hives, breathing difficulty or swelling after contrast, in which case alert staff or call emergency services? boundary
- What is computed tomography, and how does it differ from MRI, plain X-rays, PET and ultrasound? definition
Forms
Named forms.
Forms
Forms.
- What are cardiac CT, HRCT, electron beam CT, CT myelography, CT arthrography and industrial CT measurement? definition
- Which entry fits the specific form? action
Physics Principles.
Science.
Reconstruction
Image reconstruction.
Reconstruction
Reconstruction.
- How do filtered back projection and iterative methods reconstruct images? provenance
- Which references are standard? provenance
Hounsfield units
Hounsfield units.
Hounsfield units
Hounsfield units.
- What does the Hounsfield scale measure? measurement
- Which sources are cited? provenance
Safety Safety.
Regulation.
Dose
Radiation dose.
Dose
Dose.
- How do justification and dose optimisation reduce CT risks, in general terms? provenance
- Which entry fits ALARA? action
Contrast
Contrast safety.
Contrast
Contrast.
- What precautions apply to iodinated contrast for allergies and kidney function? provenance
- Which entry fits contrast-induced nephropathy? action
Context History and industry.
Context.
History
Invention.
History
History.
- How did Hounsfield develop CT at EMI? provenance
- Which entry fits Godfrey Hounsfield? action
Industry
Industrial CT.
Industry
Industry.
- How is CT used for non-destructive testing and metrology? provenance
- Is the information current? boundary
What the second pass must settle
- Should industrial CT be a separate entry?
- How should imaging appropriateness guidance be linked?
- Should electron beam CT be marked as largely historical?