QUESTIONS AND CORRECT ANSWERS (VERIFIED
ANSWERS) Q&A 2026 |INSTANT DOWNLOAD PDF
1. What is the primary magnetic field in MRI called?
A. Gradient field
B. Radiofrequency field
C. B0 field
D. Shielding field
Rationale: The primary magnetic field aligns hydrogen protons
and is denoted as B0. Gradient fields create spatial encoding,
and RF fields excite protons.
Correct answer: C
2. Which nucleus is most commonly imaged in MRI?
A. Carbon-13
B. Sodium-23
C. Oxygen-17
D. Hydrogen-1 (protons)
Rationale: Hydrogen is abundant in water and fat, giving a
strong MRI signal. Other nuclei are less sensitive.
Correct answer: D
,3. What does T1 relaxation time represent?
A. Time for protons to lose phase coherence
B. Time for protons to realign with the magnetic field
C. Time to reach 50% magnetization in the transverse plane
D. Time for signal decay due to inhomogeneities
Rationale: T1 reflects longitudinal recovery, returning protons
to equilibrium along B0.
Correct answer: B
4. T2 relaxation time is influenced by:
A. Proton density
B. Spin-spin interactions
C. Magnetic field strength only
D. RF pulse duration
Rationale: T2 is the transverse relaxation due to energy
exchange between nearby spins.
Correct answer: B
5. Which MRI sequence is best for detecting edema?
A. T1-weighted
B. Proton density
C. T2-weighted
D. Gradient echo
,Rationale: Edema has high water content, appearing bright on
T2-weighted images.
Correct answer: C
6. What is the purpose of gradient coils in MRI?
A. Produce B0 field
B. Generate RF energy
C. Spatially encode the MRI signal
D. Shield the magnet from external interference
Rationale: Gradient coils alter the main magnetic field linearly
to localize signals in space.
Correct answer: C
7. Which of the following is a contraindication for MRI?
A. Claustrophobia
B. Pacemaker or ICD
C. Mild obesity
D. Diabetes
Rationale: Metallic implants like pacemakers can malfunction
or heat during MRI. Claustrophobia is a relative, not absolute,
contraindication.
Correct answer: B
8. SAR (Specific Absorption Rate) refers to:
, A. Proton spin alignment
B. Rate of RF energy absorbed by tissue
C. Gradient coil heating
D. Magnetic susceptibility
Rationale: SAR measures tissue heating due to RF exposure;
limits are regulated for patient safety.
Correct answer: B
9. Which MRI pulse sequence uses a 90° RF pulse followed by
a 180° refocusing pulse?
A. Gradient echo
B. Inversion recovery
C. Spin echo
D. EPI
Rationale: Spin echo sequences reduce effects of
inhomogeneities using a 180° pulse.
Correct answer: C
10. Which imaging plane divides the body into left and right
halves?
A. Axial
B. Coronal
C. Sagittal
D. Oblique