Computed Tomography Test Computed Tomography Science 2

Question 1

Which term describes the ability of a CT system to distinguish between two objects with very similar attenuation values?

Accepted Answer

Low-contrast resolution

Answer

Low-contrast resolution (contrast resolution) measures the system's ability to differentiate objects with nearly identical attenuation coefficients.

Question 2

In CT, the process of reconstructing an image from projection data using mathematical algorithms is called:

Accepted Answer

Filtered back-projection

Answer

Filtered back-projection (FBP) applies a convolution filter to raw projection data before back-projecting it to form the image.

Question 3

The Hounsfield unit (HU) value of cortical bone is approximately:

Accepted Answer

+1000 HU

Answer

Cortical bone typically measures around +1000 HU on the Hounsfield scale, with water at 0 HU and air at -1000 HU.

Question 4

Which detector configuration in multi-detector CT (MDCT) acquires data simultaneously from multiple rows, allowing faster volume coverage?

Accepted Answer

Multi-row detector array

Answer

Multi-row detector arrays allow simultaneous acquisition of multiple slices per gantry rotation, dramatically increasing volume coverage speed.

Question 5

What effect does increasing the pitch in helical CT have on patient dose?

Accepted Answer

Decreases dose by reducing overlap

Answer

Increasing pitch means the table moves faster per rotation, resulting in less beam overlap and a reduced effective dose to the patient.

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