100% satisfaction guarantee Immediately available after payment Both online and in PDF No strings attached
logo-home
Previously searched by you
Previously searched by you
logo
Medical Biophysics 2500 Quiz 1 || Already Passed. CA$15.62
Add to cart
Quickly navigate to
Preview
  2.  
  3. Medical Biophysics 2500
  4.  
  5. Medical Biophysics 2500

Exam (elaborations)

Medical Biophysics 2500 Quiz 1 || Already Passed.
 2 views  0 purchase
  • Course
  • Medical Biophysics 2500
  • Institution
  • Medical Biophysics 2500

What Is attenuation? correct answers gradual reduction in intensity of signal How is attenuation caused? correct answers By the scattering and absorption of photons When are collisions most likely? correct answers When the material is dense More dense allow high or low x-rays out? correct ...

[Show more]

Preview 2 out of 5  pages

Document information

  • December 15, 2024
  • 5
  • 2024/2025
  • Exam (elaborations)
  • Questions & answers

Subjects

  • what is attenuation

Written for

  • Medical Biophysics 2500
  • Medical Biophysics 2500

Seller

avatar-seller
FullyFocus

Reviews received

Content preview

Medical Biophysics 2500 Quiz 1 || Already Passed.
What Is attenuation? correct answers gradual reduction in intensity of signal

How is attenuation caused? correct answers By the scattering and absorption of photons

When are collisions most likely? correct answers When the material is dense

More dense allow high or low x-rays out? correct answers Less x-rays out

Less dense allows high or low x-rays out? correct answers More x-rays out

What does full attenuation mean? correct answers x-rays don't reach the film/sensor, so the film
looks white

What does partial attenuation mean? correct answers some rays reach the film/sensor so the film
looks grey

What does no attenuation mean? correct answers all x-rays reach the film/sensor so the film
looks black

What does the attenuation coefficient (µ) describe? correct answers the fraction of a beam of x-
rays absorbed or scattered per unit thickness of the material

What are the 4 primary densities? correct answers 1. Bone
2.Water
3.Fat
4.Gas

What does the white in x-rays mean? correct answers That the material is the thickest

How do CT scans work? correct answers Uses multiple slices of x-rays that are stacked to create
a 3D image

Is there attenuation in CT scans? correct answers No. It is removed in order to see the finer
details

Why do we need more than 1 angle? correct answers Some angles can make the same object
look different or vice versa

How are Hounsfield numbers calculated? correct answers µvoxel - µwater /µwater

Are all organs equally sensitive to radiation? correct answers No

As x-rays are attenuated, where is the energy going? correct answers energy is delivered to the
tissues which are ionized and can lead to DNA damage

, Which organs are most sensitive? correct answers Organs with cells that divide rapidly

What is effective dose? correct answers Effective dose = equivalent dose x weighting factor

What is contrast resolution? correct answers The ability to distinguish many shades of gray from
black to white (intensity of image)

What are phantoms? correct answers specially designed objects to tune the performance of
various imaging devices

What are artifacts? correct answers Artificial image features which arise from physics of
imaging, problems with scanners and motion of the patient

Bones appear which in X-rays because...? correct answers They highly attenuated x-rays

CT numbers are also called...? correct answers Houndsfield units

True or false: Tissue appears darker than air in x-ray because of proton density? correct answers
False

True or false: An abdominal radiograph exposes the patient to less biologically effective
radiation dose than an abdominal CT scan correct answers True

True or false: The transmission of an x-ray through two attenuating materials is independent of
their order of placement in the x-ray beam correct answers True

True or false: Tissue appears darker than air in an x-ray because of the linear attenuation of x-
rays correct answers True

What are the strengths of x-rays? (3) correct answers 1. Cheap
2. Quick and available
3.good at distinguishing bone from tissue

What are the weaknesses of x-rays? (4) correct answers 1. some radiation
2.Attenuation shawdows overlap
3.Cant distinguish difference tissues
4. Many slices needed to see finer detail

What are the strengths of CT scans? (3) correct answers 1. Good at see overlying structures
2. View at different angles
3.Can image soft tissues

What are the weaknesses of CT scans? (2) correct answers 1. Exposure to radiation
2.Expensive

The benefits of buying summaries with Stuvia:

Guaranteed quality through customer reviews

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

Quick and easy check-out

You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.

Focus on what matters

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 these notes from?

Stuvia is a marketplace, so you are not buying this document from us, but from seller FullyFocus. Stuvia facilitates payment to the seller.

Will I be stuck with a subscription?

No, you only buy these notes for CA$15.62. You're not tied to anything after your purchase.

Can Stuvia be trusted?

4.6 stars on Google & Trustpilot (+1000 reviews)

56326 documents were sold in the last 30 days

Founded in 2010, the go-to place to buy study notes for 14 years now

Start selling
CA$15.62
  • (0)
Add to cart
Added