| 摘要 |
Radiation damping (RD) is employed to hasten the recovery of longitudinal magnetization after RF excitation and signal readout in a magnetic resonance measurement cycle. A switch driven by the pulse sequence that performs the measurement cycle energizes a feedback RF coil driven by an amplified and phase shifted portion of the received MR signal. The recovery of longitudinal magnetization is thus under direct control of the MR system and enables the reduction of the otherwise inefficient waiting times that are required for natural T1 recovery of the excited spin magnetization. This enables shortened acquisition times, improved sensitivity, better spatial and temporal resolution, and reduction of motion artifacts that result from long acquisition times.
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