MRI Cheat Sheet 2026

The 30 highest-yield MRI facts, distilled from real exam questions. Print it, save it as a PDF, or study it here — free, no sign-up.

1. What is the relationship between voxel size and SNR in MRI? → Larger voxels produce higher SNR
2. Inversion recovery sequences null a specific tissue when the readout pulse is applied at time TI equal to: → 0.693 × T1 of the tissue (T1 × ln2)
3. In MR imaging, the signal-to-noise ratio (SNR) improves with increasing field strength approximately as: → Linearly (proportional to B0)
4. A 'DC offset' or 'center dot' artifact seen as a bright spot in the center of the image is related to: → A small DC current offset in the receiver causing a spike in the center of k-space
5. A patient is claustrophobic and anxious before their MRI. Which non-pharmacological intervention is most appropriate first? → Explain the procedure, offer a patient communication system, and consider feet-first entry
6. During an MRI exam, a patient begins experiencing intense burning sensations on their skin near monitoring cables. What is the most likely cause? → RF-induced heating from looped or coiled cables
7. What is the effect of reducing the number of phase-encoding steps while keeping FOV and frequency steps constant? → Scan time decreases and phase-direction spatial resolution decreases
8. For MRI of the breast, the patient should be positioned in which orientation? → Prone with breasts hanging freely in a dedicated bilateral breast coil
9. Diffusion tensor imaging (DTI) and tractography are primarily used to evaluate which brain structure? → White matter fiber tracts and connectivity
10. For MRI of the internal auditory canals (IACs), which imaging plane is most commonly used as the primary plane? → Axial
11. Which parameter in MRI controls the field of view (FOV) and therefore directly affects spatial resolution when matrix size is held constant? → FOV size relative to matrix (voxel size = FOV/matrix)
12. MR Conditional implants are safe to scan only when: → Specific conditions of field strength, SAR, and gradient limits are met
13. Which of the following changes will increase spatial resolution without changing the FOV? → Increasing the matrix size
14. Multiple sclerosis (MS) plaques in the brain are classically found in which location on MRI? → Periventricular white matter, corpus callosum, and juxtacortical regions
15. Wraparound (aliasing) artifact in MRI is caused by: → Structures outside the FOV contributing signal that is folded back into the image
16. The echo time (TE) in gradient-echo sequences affects which type of contrast? → T2* contrast — longer TE increases T2* weighting and susceptibility effects
17. A technologist wants to reduce scan time while maintaining similar SNR. Which strategy is most effective? → Use parallel imaging (SENSE/GRAPPA)
18. Which sequence parameter directly controls the slice thickness in a 2D spin-echo acquisition? → Bandwidth of the RF pulse divided by the slice-select gradient amplitude
19. Which MRI screening form section is most critical for identifying implanted devices that may be MR Unsafe? → Implants and devices section
20. This kind of magnetic shielding confines the main magnet's field by using other magnets and their corresponding magnetic fields. → Active
21. Which technique is most effective for reducing susceptibility artifact from a metallic implant in MRI? → Use a spin-echo or fast spin-echo (FSE) sequence with narrow bandwidth
22. IV line tubing and monitoring cables used inside the MRI suite must be: → MR-conditional equipment specifically rated for use in the magnetic field
23. A 'corduroy' or 'herringbone' artifact covering the entire image is most often caused by: → A spike (impulse noise) in k-space
24. On an axial MRI of the abdomen at the level of L1, which structure is seen as a round low-signal structure anterior to the aorta? → Superior mesenteric artery
25. A patient reports a prior allergic-like reaction to a GBCA. Which of the following is the recommended premedication protocol? → Corticosteroid + antihistamine, with the first steroid dose 13 hours before injection
26. What is the preferred patient position and coil for imaging the rotator cuff of the shoulder? → Supine, arm at side in neutral rotation, dedicated shoulder coil
27. The corpus callosum is best evaluated on which MRI plane for assessing callosal agenesis? → Sagittal
28. What happens to image contrast when the echo time (TE) is increased in a T2-weighted sequence? → T2 contrast increases as tissues with short T2 decay faster
29. Which artifact appears as parallel bright and dark bands in the phase-encoding direction when the FOV is too small and the patient extends beyond it? → Aliasing (wraparound)
30. In a spin echo (SE) sequence, increasing the repetition time (TR) while keeping TE short primarily results in: → Decreased T1 weighting (more proton density/T2-like contrast)