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
Mosby CT Registry Review Questions with 100% Verified Correct Answers $10.99
Add to cart
Quickly navigate to
Preview
  2.  
  3. CT Registry
  4.  
  5. CT Registry

Exam (elaborations)

Mosby CT Registry Review Questions with 100% Verified Correct Answers
 0 purchase
  • Course
  • CT Registry
  • Institution
  • CT Registry

Mosby CT Registry Review Questions with 100% Verified Correct Answers What is the smallest component of a digital image - Correct Answer pixel How many CT numbers are assigned to each pixel in the image matrix? - Correct Answer One In a CT image, the CT number - Correct Answer Of a material ...

[Show more]

Preview 4 out of 62  pages

Document information

  • August 18, 2024
  • 62
  • 2024/2025
  • Exam (elaborations)
  • Questions & answers

Subjects

  • what is the smallest component of a digital image
  • how many ct numbers are assigned to each pixel in
  • in a ct image the ct number
  • each two dimensional square of data that make up t

Written for

  • CT Registry
  • CT Registry

Seller

avatar-seller
Winfred

Reviews received

Content preview

Mosby CT Registry Review Questions with
100% Verified Correct Answers
What is the smallest component of a digital image - Correct Answer pixel



How many CT numbers are assigned to each pixel in the image matrix? - Correct Answer One



In a CT image, the CT number - Correct Answer Of a material is dependent on its linear attenuation
coefficient



Each two-dimensional square of data that make up the CT image is called a - Correct Answer pixel



What is an element of the digital image - Correct Answer pixel



Which of the following influences the spatial resolution in cardiac CT imaging - Correct Answer
*detector size

*reconstruction interval

*pitch



As patient motion increases spatial resolution decreases - Correct Answer TRUE



Which is an advantage of using a small focal spot - Correct Answer increased spatial resolution



Increasing the CT image matrix from 256x256 to 512x512 will likely improve? - Correct Answer High-
contrast spatial resolution



The practical limiting spatial resolution of a CT scanner is 3.6 lp/cm. What size object does this
correspond to? - Correct Answer 1.4 mm



Use of a bone filter, as opposed to a soft tissue filter, to reconstruct CT images would likely improve?
- Correct Answer Spatial resolution



The spatial resolution of a typical CT scanner is on the order of? - Correct Answer 1 mm

,A 512 x 512 matrix CT image over a 30-cm field of view could show a spatial resolution of no better
than ? lp/cm? - Correct Answer 8.5



When comparing a 512x512 matrix to a 1024x1024 matrix, the 1024x1024 matrix? - Correct Answer
Contains four times as many pixels: 1024 x 1024 =1048576 then 512 x 512= 262144...then divide
1048576 /262144 = 4



High contrast spatial resolution and low contrast resolution are typically measured baseline and ?
thereafter - Correct Answer Biannually



To improve the high contrast spatial resolution of a CT study, one would increase _____ while
keeping all other factors the same. - Correct Answer Matrix size (128x128 to 512x512)



A radiologist wants to improve the high-contrast spatial resolution of anatomy which he/she is
examining by CT. The change which would best lead to this improvement is - Correct Answer Increase
the matrix size



To improve the high-contrast spatial resolution of a CT study, one could increase ? while keeping all
other factors the same? - Correct Answer Matrix size



A voxel contains 25% air, 50% water and 25% bone. The CT number for this voxel would be expected
to be _____ HU? - Correct Answer 0



How many pixels are contained in a 1,024 matrix image? - Correct Answer D. 1,048,576



MATH 1024 X1024



It is located in a matrix and is a two dimensional representation of a voxel - Correct Answer pixel



When CT numbers are calculated for voxels (volume elements) of tissue what is assigned the
calculated number and a subsequent shade of gray - Correct Answer pixel



What is defined as a picture element or the smallest component of the digital image - Correct
Answer pixel

,A CT scan produces a 512x512 matrix transverse image of a 30 cm diameter FOV. Each pixel is
approximately _____ mm on a side. - Correct Answer 0.6 equation: 30cm/512= .058cm convert to
mm and its .58 which is approximately 0.6



The ability of a system to define small objects distinctly is referred to as which of the following? -
Correct Answer spatial resolution



Which of the following terms is/are commonly used to describe a CT scanner's ability to differentiate
objects with similar linear attenuation coeffiecents - Correct Answer *spatial resolution

*sensitivity



Which of the following factors have an affect on contrast resolution - Correct Answer *patient size

*slice thickness

*pixel size

*mAs/dose



As mAs/dose increases contrast resolution decreases - Correct Answer FALSE



As mAs/dose increases contrast resolution INCREASES - Correct Answer TRUE



The ability of a CT scanner to accurately image objects with similar densities is termed - Correct
Answer *contrast resolution

*sensitivity



Which of the following has a direct relationship on increasing contrast resolution - Correct Answer
*mAs/dose increase

*Slice thickness



For a particular CT scanner's beam quality, the linear attenuation coefficient for water is 0.20 cm-1
and for a certain tumor is 0.21 cm-1. What is the CT number of the tumor? - Correct Answer 50.
Equation (.21-.20/.21) × 1000= 50

, A CT scanner with poor contrast resolution or low sensitivity has difficulty separating - Correct
Answer tissues whose linear attenuation coefficients are nearly equal



What is the basic physical quantity being measured by a CT system - Correct Answer Linear
attenuation coefficient



Assume the linear attenuation coefficient is 0.20 cm-1 for water and 0.40 cm-1 for tissue within a
given voxel. What is the CT number in Hounsfield units for the pixel representing this voxel? - Correct
Answer +1,000....Equation { (.4-.2) /.2} x 1000



What fraction of monoenergetic x-rays will be absorbed by a 20-cm thick material having a linear
attenuation coefficient of 0.05 cm-1? - Correct Answer 0.63



The contrast resolution of CT is approximately ? % - Correct Answer 0.3 to 0.6



This term describes the ability CT scanner to differentiate objects with MINIMAL differences in
attenuation coefficients - Correct Answer contrast resolution



What is the term for resolution of a CT scanner referred to as the system's ability to differentiate
objects with SIMILAR densities. - Correct Answer contrast resolution



In order to pass ACR CT accreditation, the CT scanner's adult head protocol must be within - Correct
Answer 1.0



The QC test for the average CT number for water should be done - Correct Answer Daily



The following are all basic tenets of a QC program for computed tomography scanner - Correct
Answer *QC test must be conducted regularly

*Accurate record keeping

*all test results must be interpreted promptly



Using the ACR CT accreditation phantom, module 3 is used to measure which of the following -
Correct Answer CT number uniformity

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 Winfred. Stuvia facilitates payment to the seller.

Will I be stuck with a subscription?

No, you only buy these notes for $10.99. You're not tied to anything after your purchase.

Can Stuvia be trusted?

4.6 stars on Google & Trustpilot (+1000 reviews)

69052 documents were sold in the last 30 days

Founded in 2010, the go-to place to buy study notes for 15 years now

Start selling
$10.99
  • (0)
Add to cart
Added