MRI MRI Image Quality and Optimization 2

Question 1

Which coil type generally provides the highest SNR for imaging a small superficial structure?

Accepted Answer

Surface coil

Answer

Surface coils placed close to the target anatomy have superior SNR for small or superficial structures because they detect signal from a limited volume with less noise.

Question 2

What is the effect of increasing receiver bandwidth on MRI image quality?

Accepted Answer

SNR decreases but chemical shift artifact is reduced

Answer

Increasing bandwidth reduces chemical shift artifact and allows shorter TE/TR, but more noise is accepted per unit time, lowering SNR.

Question 3

In MRI, what does the term 'k-space' represent?

Accepted Answer

The raw frequency-domain data before Fourier transformation into an image

Answer

K-space is the mathematical frequency domain where raw MRI data is stored; a Fourier transform converts k-space data into the final spatial image.

Question 4

Which portion of k-space primarily determines image contrast?

Accepted Answer

The center (low spatial frequencies)

Answer

The center of k-space contains low spatial frequency data, which encodes the bulk signal intensity and contrast of the image.

Question 5

A technologist increases slice thickness from 3 mm to 6 mm. What is the expected change in image quality?

Accepted Answer

SNR improves but through-plane resolution decreases

Answer

Thicker slices contain more protons and generate more signal, improving SNR, but fine anatomical detail in the through-plane direction is reduced.

MRI - Magnetic Resonance Imaging Practice Test

MRI - Magnetic Resonance Imaging Practice Test

MRI MRI Image Quality and Optimization 2