Exam (elaborations)
Physical Principles of Computed Tomography questions with verified answers
- Course
- Institution
Physical Principles of Computed Tomography questions with verified answers
[Show more]
Seller
Follow
BravelRadon
Reviews received
Content preview
Physical Principles of ComputedTomography
Goal of CT - correct answer ✔✔Minimal superimposition, Improved image contrast, very small
differences in tissue contrast
Physical principles - correct answer ✔✔Data Acquisition, Data processing, Format of CT image, Data flow
in a CT scanner, Sequence of events, Advantages of CT, Limitations of CT
Data Acquisition - correct answer ✔✔Systematic collection of information from the patient to produce
CT image, Slice by slice data acquisition(axial), x-ray tube rotates around the patient, data is collected
from the single slice, the tube stops, patient moves to the next location
Volume data acquisition - correct answer ✔✔Volume or helical scanning, x-ray tube rotates around the
patient and traces a spiral path to scan an entire volume of tissue, relative transmission(attenuation
measurements) values are sent to the computer and stored as raw data, large number of transmission
measurements are needed to reconstruct the CT image
Radiation attenuation - correct answer ✔✔amount of attenuation in the tissues is used to reconstruct an
image, attenuation is the reduction of intensity of a beam of radiation as it passes through an object,
either through absorption or scatter, depends on electrons per gram, atomic number, tissue density, and
radiation energy used
Homogenous beam - correct answer ✔✔All photons have same energy, Also called monochromatic or
monoenergetic beam, Used in Houndsfield's first ct scanner because of Lambert-Beer law, Each section
of absorber attenuates beam by equal amounts, Quality of beam(beam energy) does not change, Start
with 80 keV, the transmitted photons all have an energy of 80keV, Takes longer to produce, Attenuation
is exponential
Heterogeneous beam - correct answer ✔✔Photons have different energy, also called, polychromatic
beam, Used in CT x-ray tubes now. As beam passes through equal thickness the, attenuation quantity
and quality changes, Mean kV of the photons increases as it passes through, material(low energy
photons are absorbed)
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through EFT, credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying this summary from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller BravelRadon. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy this summary for R186,30. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
75632 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy summaries for 14 years now