Signal-to-noise ratio in MRI.

in RF receiving coil design. However, modern is proportional to 0 , so that their population imaging techniques often demand very high speed difference is larger at high values of 0 . Since the and spatial resolution, so that the highest possible ratio of the energy difference to thermal energy is SNR is still required to avoid poor image quality. very small, the population difference increases in In this commentary, the physics underlying the direct proportion to 0 , as does the size of the variation of SNR with static field strength will be nuclear magnetic dipole moment. Secondly, the briefly reviewed, practical methods of optimizing Larmor frequency at which the dipole moment SNR will be outlined, including a discussion of the precesses is proportional to 0 so that the rate of principles of quadrature and phased-array RF change of flux linked to the RF coil also increases coils, and methods of measuring SNR for acceptin proportion to 0 . Therefore, by Faraday’s law ance testing and quality assurance will be of electromagnetic induction, the signal produced discussed. by a dipole magnetic moment of constant magni-