MRI EXAM QUESTIONS

A patient is undergoing a time of flight magnetic resonance angiography. Unfortunately, nuclei are not being excited and red-phased and consequently, no MR signal is produced. What can an MRI radiographer do to correct this issue? a. Change the patient orientation b. Increase the repetition time c. Increase the slice thickness d. Use a 90º RF pulse followed by a 180º RF pulse e. Use a contrast agent

C. INCREASE SLICE THICKNESS

Which MRI pulse sequence uses a 90º excitation pulse followed by 180º rephasing pulse followed by an echo as seen in the figure below? a. Conventional spin echo b. Fast spin echo c. FLAIR d. Gradient echo e. STIR

Conventional spin echo

What MRI image will be produced with a spin echo pulse sequence having a short TR and short TE value? a. DWI b. FLAIR c. PDWI d. T1WI e. T2WI

D. T1wi

Which extrinsic contrast parameter is unique to inversion recovery sequences like STIR and FLAIR? a. Flip angle b. T1 c. T2 d. TI e. Turbo factor

D. TI

What is the NMV

EXCESS parallel spins

What is the MR active nuclei in MRI

HYDROGEN

What determines T2 recovery time

How closely packed the molecules are

Why is hydrogen the MRI active nuclei used

LARGE ABUNDANCE LARGE MAGNETIC MOMENT

There are certain absolute contraindications to MRI. Which condition, situation or medical implant, when present excludes a patient from getting an MRI? a. Artificial heart valve b. Acritical hips c. Claustrophobia d. Pacemaker e. Pregnancy

Pacemaker

In MRI safety what does SAR stand for: Specfic absorption rate

Specfic absorption rate

Which parameter is unique to FSE FLIP ANGLE PROTON DENSITY T1 T2 TURBO FACTOR

TURBO FACTOR

Which tissue has longest T1 AND T2 time

WATER

Which extrinsic contrast parameter controls how imaging is derived in diffusion weighted imaging? a. B factor b. Flip angle c. Gyromagnetic ratio d. T2* e. Turbo factor

a. B factor

In MR, resonance is induced by applying a radiofrequency pulse and it is imperative in the creation of the MR signal. Which of the following is a recruitment for resonance to occur between two objects? a. Both objects oscillate at the same frequency b. Both objects oscillate but at different frequencies c. Both objects remain stationary d. Both objects stretch in the same direction e. One object oscillates and the other object is stationary

a. Both objects oscillate at the same frequency

FMRI uses blood oxygen level dependence (BOLD) to exploit differences in the magnetic susceptibility of oxyhaemoglobin and deoxyhaemoglobin. Which MRI contrast parameter, controlled by the MRI operator, is used to acquire FMRI? a. Flip angle b. TE c. TF d. TI e. TR

b. TE

Question 13: FMRI is a rapid MR technique that acquires images of the brain during an activity or stimulus and at rest. The most important physiological effect that produces MR signal intensity changes between a stimulus and a rest is called Blood Oxygenation Level Dependence (BOLD). Which pulse sequence is used in FMRI specifically because BOLD effects are very short lived? a. Conventional spin echo b. Echo imaging c. Fast gradient echo d. Fast spin echo e. Turbo echo

c. fast gradient echo

hich of the following system compensates for the inhomogeneity in the main magnetic field and creates magnetic field homogeneity or evenness? a. Coil system b. Data acquisition system c. Gradient system d. Radiofrequency system e. Shim system

e. SHIM system

When nuclei are placed in an external magnetic field, their magnetic moments line up with the magnetic field flux lines. This is called alignment. Based on the quantum theory, nuclei that aligned in the anti- parallel direction are said to be in which energy state? a. Equal b. High c. Low d. Medium e. Zero

high