Magnetic Resonance Imaging (MRI) Practice Test

Disable ads (and more) with a membership for a one time $2.99 payment

Study for the Magnetic Resonance Imaging (MRI) Test. Utilize flashcards and multiple choice questions with detailed hints and explanations. Get thoroughly prepared for your MRI exam!

Each practice test/flash card set has 50 randomly selected questions from a bank of over 500. You'll get a new set of questions each time!

Practice this question and more.


What does increased NEX primarily affect in an MRI scan?

  1. Scan time

  2. Image contrast

  3. Spatial resolution

  4. Magnetic field strength

The correct answer is: Scan time

In an MRI scan, increasing the number of excitations (NEX) primarily affects scan time. NEX refers to the number of times the same slice of tissue is sampled to improve the Signal-to-Noise Ratio (SNR) of the acquired images. By acquiring more data points from the same slice, the scan takes longer, as it requires multiple repetitions of the imaging sequence. This repetition helps enhance the quality of the final image, resulting in clearer visualization of anatomical details. While increasing NEX can contribute to better SNR and overall image quality, it does so at the expense of longer examination times, making it a crucial consideration in balancing image quality with patient throughput. Other factors, such as image contrast and spatial resolution, are influenced by different parameters like the choice of pulse sequences, the magnetic field strength, or values like matrix size and voxel dimensions, rather than simply increasing NEX.