MRI

In MRI, TR primarily controls which type of contrast weighting?

In spin-echo imaging, TE primarily influences:

The Ernst angle is the flip angle that:

Compared with spin-echo, gradient-echo (GRE) sequences are more sensitive to:

FLAIR is an inversion-recovery sequence designed to:

STIR is primarily used to:

Chemical shift artifact (Type 1) occurs along which axis?

Increasing receiver bandwidth generally:

Parallel imaging (e.g., SENSE/GRAPPA) reduces scan time by:

Slice thickness is primarily set by:

Increasing NEX/NSA from 1 to 4 changes SNR by approximately:

Diffusion-weighted imaging contrast increases with higher:

Restricted diffusion typically appears as:

Time-of-flight (TOF) MRA relies on:

Phase-contrast (PC) MRA encodes:

BOLD fMRI signal mainly reflects:

At 3T compared with 1.5T, susceptibility artifacts are:

A zipper artifact across the image most often indicates:

Wrap-around (aliasing) occurs when:

Gradient duty cycle and dB/dt are safety concerns primarily due to:

SAR (specific absorption rate) is most affected by:

The projectile effect risk zone in MRI is designated as:

“Conditional” cardiac devices in MRI require:

Gadolinium-based contrast is relatively contraindicated in:

Dielectric shading at 3T is reduced by:

Flow compensation (gradient moment nulling) is used to:

Chemical fat suppression (SPAIR/SPIR) fails near metal mainly due to:

Dixon (fat–water) techniques separate signals by:

In-phase vs out-of-phase imaging is most useful for detecting:

Susceptibility artifacts are greatest with which readout?

Balanced SSFP (bSSFP/TrueFISP) images show:

Increasing matrix size (same FOV) primarily:

Motion ghosting typically appears along the:

k-space center primarily determines:

A magnet “quench” refers to:

Flow voids on spin-echo vascular images are due to:

Which adjustment most reduces susceptibility artifact?

For acute stroke MRI, DWI/ADC shows:

In MR safety screening, which item is high risk?

To shorten scan time without changing TR, you can primarily:

Chemical shift artifact Type 2 (“India ink”) appears as:

At 1.5T, a common FLAIR TI to null CSF is approximately:

A typical STIR TI to null fat at 1.5T is about:

The main trade-off when increasing receive bandwidth is:

Parallel imaging penalty most directly reflected by:

Best fix for bSSFP banding artifacts:

Diffusion EPI geometric distortion is reduced by:

Failure of chemical fat suppression near metal is mainly due to:

In-phase/out-of-phase liver imaging helps detect:

On MR spectroscopy, major peaks are typically at:

Lactate at TE ~135 ms characteristically:

Black-blood vessel wall imaging uses:

TOF MRA relies on:

Phase-contrast MRA encodes flow by:

Most effective way to reduce SAR in a TSE sequence:

Patient with MR-conditional pacemaker is scanned only when:

Primary risk from rapidly switched gradients is:

Dielectric shading at 3T is mitigated by:

Slice crosstalk is minimized by:

Partial Fourier (half-Fourier) trade-off:

Balanced SSFP contrast is primarily:

Best way to shorten scan time without changing TR/TE in 2D:

For acute stroke, DWI shows:

T2 shine-through is confirmed by:

Late gadolinium enhancement (LGE) nulling in myocardium aims to:

Ischemic infarct LGE pattern is typically:

Myocarditis LGE pattern commonly:

Arterial spin labeling (ASL) measures:

Best parameter change to reduce susceptibility artifact on GRE:

Wrap-around (aliasing) prevention option:

Coils: surface coil vs. body coil—SNR behavior?

Primary function of shimming:

Gadolinium in severe renal failure risk:

MR room safety zones:

Balanced SSFP artifacts around metal are reduced by:

DTI primary metric of anisotropy:

Motion ghosting is seen along which axis?

Dixon fat–water imaging advantage over chemical fat sat:

Main cause of “zipper” artifact:

To shorten a 3D GRE acquisition without changing TR/TE, you can:

Spoiled GRE (SPGR/FLASH) differs from balanced SSFP mainly in that it:

After gadolinium, which fat-suppression method is most appropriate for lesion conspicuity?

The “magic angle” effect causes increased tendon signal when fibers are oriented about:

Very long echo train length (ETL) in TSE/FASE most commonly produces:

In carotid 3D TOF MRA, to suppress venous signal you should place the saturation band:

In phase-contrast MRA, a VENC set too low will primarily cause:

Susceptibility artifact is usually worst at:

Around metallic implants, which sequence class typically minimizes blooming and distortion?

Multi-shot or segmented EPI DWI (e.g., RESOLVE) mainly helps by:

For contrast-enhanced MRA, centric k-space ordering is preferred because it:

Opposed-phase echo time at 1.5T is approximately:

Zero-filling interpolation primarily:

Nyquist (N/2) ghosting in EPI most commonly arises from:

Which change most reduces EPI geometric distortion?

SAR tends to scale with which parameter relationship?

To prevent RF burns, you should primarily:

Compared with 1.5T, T1 relaxation times at 3T are generally:

Balanced SSFP band spacing is primarily related to:

Respiratory motion reduction for liver MRI is best achieved with:

ECG gating primarily aims to:

Flow-compensated (gradient moment–nulled) sequences mainly reduce artifacts from:

MR-conditional implants can be scanned when:

First-trimester non-contrast MRI is generally:

Claustrophobia management in MRI can include:

SEMAC/MAVRIC metal reduction techniques primarily:

On diffusion, T2 shine-through should be distinguished from true restriction by:

The principal benefit of Dixon fat suppression over spectral fat sat is:

If opposed-phase liver imaging shows marked signal drop in an adrenal mass, the most likely diagnosis is: