Computed Tomography Test CT Image Quality and Reconstruction

Question 1

In CT, spatial resolution is most commonly measured using which parameter?

Accepted Answer

Modulation Transfer Function (MTF) or line pairs per centimeter (lp/cm)

Answer

Signal-to-noise ratio (SNR)

Answer

Hounsfield Unit (HU) accuracy

Answer

Contrast-to-noise ratio (CNR)

Question 2

What is the Hounsfield Unit (HU) value of water on a CT scan?

Accepted Answer

0 HU

Answer

−1000 HU

Answer

+1000 HU

Answer

+100 HU

Question 3

Which reconstruction algorithm provides the sharpest images but also the most noise in CT?

Accepted Answer

High-frequency (bone/edge) kernel

Answer

Soft-tissue kernel

Answer

Lung kernel

Answer

Iterative reconstruction

Question 4

What does the term 'partial volume effect' describe in CT imaging?

Accepted Answer

Averaging of attenuation from different tissues within a single voxel

Answer

Loss of signal at scan edges

Answer

Artifact from metal implants

Answer

Increased noise at the image periphery

Question 5

In CT, increasing the field of view (FOV) while keeping matrix size constant will have what effect on voxel size?

Accepted Answer

Voxel size increases, reducing spatial resolution

Answer

Voxel size decreases, improving spatial resolution

Answer

Voxel size stays the same

Answer

FOV does not affect voxel size

Question 6

What type of CT artifact appears as dark streaks radiating from dense metallic objects such as hip prostheses?

Accepted Answer

Beam hardening and metal streak artifact

Answer

Ring artifact

Answer

Motion artifact

Answer

Partial volume artifact