Keywords:
Education and training, Imaging sequences, MR, MR physics
Authors:
M. Wyss1, I. Dobrev1, J. H. Sim1, T. D. J. Sartoretti2, A. Najafi2, M. Koepfli3, A. M. Huber1, C. A. Binkert2; 1Zürich/CH, 2Winterthur/CH, 3Lucerne/CH
DOI:
10.1594/ecr2018/C-2186
Aims and objectives
Strong Lorentz forces acting on the gradient coils are the source of acoustic noise in MRI.
Fast current switch in the gradient coil lead to vibration in their mountings and to emission of sound waves [1].
Acoustic noise during an MR examination is an issue in clinical MRI examinations due to impairment of communication with the operator and patient annoyance [2–5].
Various acoustic noise control techniques are available to reduce acoustic noise and improve patient comfort in MRI.
They can be categorized into passive noise control (earplugs,
headphones,
sound-attenuating material),
active noise control (active noise cancellation) [3] and techniques based on MR pulse sequence optimization [3,6].
The latter reduce gradient slew rate or use different gradient waveforms (e.g.
quiet pulse sequences or silent scan) [7,8].
This work examines the performance of an acoustic noise reduction technique based on MR pulse sequence optimization for a routine brain MR protocol.
A sound processing pipeline was established using Matlab (MathWorks,
USA).
This method includes post-processing features similar to ones integrated in handheld analyzers,
while allowing for the in-depth exploration of certain aspects of MRI noise characteristics.
Furthermore,
side effects impacting important MR sequence parameters are reported.