07) MRI Special Acquisition

In magnetization-transfer imaging, structural changes beyond the extent of the lesion seen on standard MR images may be due to all of the following EXCEPT:

A) Blood vessel occlusion

B) Previous undetected tumor

C) Myelin loss

D) Chronic edema

A) Blood vessel occlusion

In MRI, diffusion weighted imaging is useful in all of the following cases EXCEPT

A) The determination of vessel patency

B) Stroke imaging

C) Tumor imaging

D) The investigation of a demylinating processes

A) The determination of vessel patency

The signal to noise ratio of an fMRI scan can be significantly compromised by

A) The presence of a tumor near the region of activation

B) Injection of a contrast agent

C) The presence of multiple areas of activation

A) The presence of a tumor near the region of activation

In order to obtain clinically useful results from an fMRI study, one must obtain all of the following EXCEPT

A) Patient compliance with task performance

B) Minimal head movement

C) Accurate timing cues

D) Cardiac gating

Diffusion weighted MRI involves imaging:

A) The motion of water within tissues

B) Blood flow within vessels

C) Tissue volume

D) The concentration of contrast agent within blood vessels

A) The motion of water within tissues

MR spectroscopy is used to:

A) Measure tissue T1 values

B) Acquire in vivo, biochemical information

C) Gain information about the connectivity between brain regions

D) Quantify tissue blood flow

B) Acquire in vivo, biochemical information

The information that can be obtained from MRS of the tissue being investigated includes all of the following EXCEPT:

A) The relative amount of healthy tissue

B) The cellularity of the tissue

C) The degree of ischemia within the tissue

D) The blood flow

Magnetization transfer imaging can be used to

A) Visualize tissue biochemistry

B) Compare the relative volumes of tissue structures

C) Quantify blood flow

D) Measure tissue structural integrity

MR angiography can be used to investigate vessel:

A) Wall motion

B) Architecture

C) Flow tubulence

D) Stiffness

B) Architecture

10.

A relative bright spot on a diffusion weighted image means that area has:

A) Restricted diffusion relative to the surrounding tissue

B) Less restricted diffusion relative to the surrounding tissue

C) A longer T1 than the surrounding tissue

D) More susceptibility than the surrounding tissue

A) Restricted diffusion relative to the surrounding tissue

11.

In bright blood angiography, a localized area of signal decrease may appear in a vessel due to the presence of a stenosis.

A) True

B) False

A) True

12.

In acute cerebral ischemia, one would expect to see a localized signal increase on a DWI in the region of the ischemia.

A) True

B) False

A) True

13.

A region that is bright on a DWI appears dark on an ADC map.

A) True

B) False

A) True

14.

Magnetization transfer imaging is clinically important in cases of suspected myelin loss or undetected tumor.

A) True

B) False

A) True

15.

MR spectroscopy can be used to differentiate between tumor and healthy tissue.

A) True

B) False

A) True

16.

In an fMRI scan, the task timing of the paradigm that is employed affects the fMRI image result.

A) True

B) False

A) True

17.

Anaerobic metabolism can be detected using MR spectroscopy via the presence of a lactate peak.

A) True

B) False

A) True

18.

A vessel occlusion that is visible via MRA would appear as a dark spot on a diffusion weighted image..

A) True

B) False

If the lumen contains deoxy or intracellular methemoglobin one would expect dark signal on MRA. If the lumen has oxy (in cases of dissection) there will be signal in the lumen, making diagnosis difficult (bright on MRA)

19.

Magnetization transfer imaging should not be applied outside the brain.

A) True

B) False