Abstract: Accurate measurement of gradient waveform errors can often improve image quality in sequences with time varying readout and excitation waveforms. Self-encoding or offset-slice method sequences are commonly used to measure gradient waveforms. However, the self-encoding method requires a long scan time, while the offset-slice method is often low precision, requiring the thickness of the excited slice to be small compared to the maximal k-space encoded by the test waveform. This disclosure describes a novel hybrid of those methods, referred to as variable-prephasing (VP). Like the offset-slice method, VP uses the change in signal phase from offset-slices to calculate the gradient waveform. Similar to the self-encoding method, repeated acquisitions with a variable amplitude self-encoding gradient mitigates the signal loss due to phase wrapping, which, in-turn, allows thicker slices and greater SNR.

Abstract: An implantable bioresorbable radio frequency (RF) coil for high-resolution and high-specificity post-surgical evaluating or monitoring with magnetic resonance imaging (MRI) is disclosed. The coil includes a bioresorbable conductor configured to be resorbed within a patient while the coil is implanted in the patient. In one embodiment, the target application of this coil is the evaluation or monitoring (via MRI) of peripheral nerve regeneration following surgical repair.

Abstract: Accurate measurement of gradient waveform errors can often improve image quality in sequences with time varying readout and excitation waveforms. Self-encoding or offset-slice method sequences are commonly used to measure gradient waveforms. However, the self-encoding method requires a long scan time, while the offset-slice method is often low precision, requiring the thickness of the excited slice to be small compared to the maximal k-space encoded by the test waveform. This disclosure describes a novel hybrid of those methods, referred to as variable-prephasing (VP). Like the offset-slice method, VP uses the change in signal phase from offset-slices to calculate the gradient waveform. Similar to the self-encoding method, repeated acquisitions with a variable amplitude self-encoding gradient mitigates the signal loss due to phase wrapping, which, in-turn, allows thicker slices and greater SNR.

Abstract: An implantable bioresorbable radio frequency (RF) coil for high-resolution and high-specificity post-surgical evaluating or monitoring with magnetic resonance imaging (MRI) is disclosed. The coil includes a bioresorbable conductor configured to be resorbed within a patient while the coil is implanted in the patient. In one embodiment, the target application of this coil is the evaluation or monitoring (via MRI) of peripheral nerve regeneration following surgical repair.