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MRI Image Quality and Optimization Flashcards

7 cards from real MRI practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.

Read the first 7 MRI Image Quality and Optimization flashcards as text

  1. Which parameter, when increased, will most directly improve the signal-to-noise ratio (SNR) in an MRI image?

    Answer: Increasing the number of excitations (NEX/NSA)

    Increasing NEX/NSA averages more signal acquisitions, which reduces noise and improves SNR proportional to the square root of the number of averages.

  2. What is the relationship between voxel size and SNR in MRI?

    Answer: Larger voxels produce higher SNR

    Larger voxels contain more protons contributing signal, increasing SNR, though at the cost of spatial resolution.

  3. Which of the following changes will increase spatial resolution without changing the FOV?

    Answer: Increasing the matrix size

    Increasing matrix size means more phase and frequency encoding steps, reducing voxel size and improving spatial resolution within the same FOV.

  4. A technologist wants to reduce scan time while maintaining similar SNR. Which strategy is most effective?

    Answer: Use parallel imaging (SENSE/GRAPPA)

    Parallel imaging techniques use multiple coil elements to under-sample k-space, reducing scan time while maintaining acceptable SNR through reconstruction algorithms.

  5. What happens to image contrast when the echo time (TE) is increased in a T2-weighted sequence?

    Answer: T2 contrast increases as tissues with short T2 decay faster

    Longer TE allows more T2 decay to occur, so tissues with short T2 lose signal faster and appear darker, enhancing T2 contrast between tissues.

  6. Which of the following parameters most directly controls T1 contrast in a spin echo sequence?

    Answer: Repetition time (TR)

    TR determines how much longitudinal relaxation occurs between excitations; a short TR emphasizes T1 differences because tissues with shorter T1 recover faster.

  7. What is the primary trade-off when reducing the field of view (FOV) in MRI?

    Answer: Improved spatial resolution but increased risk of aliasing artifacts

    Reducing FOV increases spatial resolution by making voxels smaller, but if anatomy extends beyond the reduced FOV, aliasing (wrap-around) artifacts occur.