ARRT ARRT CT Post-Processing and Reconstruction 2

Question 1

Minimum intensity projection (MinIP) post-processing is particularly useful for displaying which anatomical structures?

Accepted Answer

Air-filled airways and lung parenchyma

Answer

MinIP projects the lowest attenuation voxel along each ray, making it ideal for displaying air-containing structures like the tracheobronchial tree or emphysematous lung.

Question 2

CT colonoscopy (virtual colonoscopy) relies on which post-processing technique to create a simulated fly-through view of the colon lumen?

Accepted Answer

Volume rendering with endoluminal navigation

Answer

Volume rendering with endoluminal navigation uses the air-distended colon as a flight path, generating a simulated colonoscopic perspective of the mucosal surface.

Question 3

What is the primary purpose of selecting a small reconstruction FOV (field of view) during CT image reconstruction?

Accepted Answer

To improve spatial resolution by sampling more detail per pixel

Answer

A smaller reconstruction FOV divides the imaged area into the same matrix of pixels, resulting in smaller pixel size and therefore higher spatial resolution of the region of interest.

Question 4

CT perfusion imaging requires specialized post-processing to generate which type of parametric maps?

Accepted Answer

Cerebral blood flow, cerebral blood volume, and mean transit time maps

Answer

CT perfusion post-processing applies deconvolution or maximum slope models to time-attenuation curves to produce quantitative maps of CBF, CBV, and MTT.

Question 5

In CT angiography post-processing, bone subtraction is performed primarily to:

Accepted Answer

Eliminate overlying bone to improve visualization of adjacent vessels

Answer

Bone subtraction algorithms register and subtract non-contrast images from contrast-enhanced images, removing osseous structures that would otherwise obscure adjacent vessels.

(ARRT) American Registry of Radiologic Technologists Computed Tomography Certification Practice Test

(ARRT) American Registry of Radiologic Technologists Computed Tomography Certification Practice Test

ARRT ARRT CT Post-Processing and Reconstruction 2