NMR imaging processor with noise filter detecting pulses

摘要

The NMR signal processor contains a filter which detects short noise impulses during a scan, measuring the signal level in frequency bands outside the imaging bandwidth. A detector receives filter output signals, generating a noise detection signal when the signal level exceeds a threshold. The NMR signals are passed to a delay circuit in parallel with the noise detector, then to a fader circuit, where the noise peaks in the NMR signal are blanked out, removing the image noise.