ARRT ARRT CT Post-Processing and Reconstruction

Question 1

Which CT post-processing technique displays only voxels above a selected threshold, making it useful for 3D visualization of bones and vascular structures?

Accepted Answer

Maximum intensity projection (MIP)

Answer

Multiplanar reformation (MPR)

Answer

Volume rendering (VR)

Answer

Surface shaded display (SSD)

Question 2

Multiplanar reformation (MPR) in CT refers to:

Accepted Answer

Reconstructing axial images into coronal, sagittal, or oblique planes

Answer

Generating 3D surface models from volumetric data

Answer

Applying color to CT images based on Hounsfield units

Answer

Subtracting pre-contrast from post-contrast images

Question 3

In CT, the filtered back projection (FBP) reconstruction algorithm applies a mathematical filter primarily to:

Accepted Answer

Correct for star artifacts inherent in simple back projection

Answer

Remove quantum noise before reconstruction

Answer

Segment soft tissue from bone

Answer

Align misregistered projection data

Question 4

Iterative reconstruction (IR) techniques in CT offer which primary advantage over filtered back projection?

Accepted Answer

Reduced image noise at the same or lower radiation dose

Answer

Faster reconstruction speed

Answer

Higher spatial resolution

Answer

Elimination of all artifacts

Question 5

Curved planar reformation (CPR) in CT is most useful for:

Accepted Answer

Straightening and displaying tortuous structures such as vessels or the spine along their entire length

Answer

Generating endoscopic views of hollow organs

Answer

Creating color-coded perfusion maps

Answer

Subtracting bone from CT angiography images

Question 6

Which post-processing technique is most appropriate for evaluating luminal stenosis of the carotid arteries on a CT angiogram?

Accepted Answer

Multiplanar reformation combined with MIP

Answer

Minimum intensity projection (MinIP)

Answer

Volume rendering alone

Answer

Standard axial images only