7T vs. 4T: RF power, homogeneity, and signal‐to‐noise comparison in head images
Magnetic Resonance in Medicine: An Official Journal of the …, 2001•Wiley Online Library
Signal‐to‐noise ratio (SNR), RF field (B1), and RF power requirement for human head
imaging were examined at 7T and 4T magnetic field strengths. The variation in B1
magnitude was nearly twofold higher at 7T than at 4T (∼ 42% compared to∼ 23%). The
power required for a 90° pulse in the center of the head at 7T was approximately twice that
at 4T. The SNR averaged over the brain was at least 1.6 times higher at 7T compared to 4T.
These experimental results were consistent with calculations performed using a human …
imaging were examined at 7T and 4T magnetic field strengths. The variation in B1
magnitude was nearly twofold higher at 7T than at 4T (∼ 42% compared to∼ 23%). The
power required for a 90° pulse in the center of the head at 7T was approximately twice that
at 4T. The SNR averaged over the brain was at least 1.6 times higher at 7T compared to 4T.
These experimental results were consistent with calculations performed using a human …
Abstract
Signal‐to‐noise ratio (SNR), RF field (B1), and RF power requirement for human head imaging were examined at 7T and 4T magnetic field strengths. The variation in B1 magnitude was nearly twofold higher at 7T than at 4T (∼42% compared to ∼23%). The power required for a 90° pulse in the center of the head at 7T was approximately twice that at 4T. The SNR averaged over the brain was at least 1.6 times higher at 7T compared to 4T. These experimental results were consistent with calculations performed using a human head model and Maxwell's equations. Magn Reson Med 46:24–30, 2001. © 2001 Wiley‐Liss, Inc.
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