METHOD FOR REMOVING BASE-LINE ERROR ARTIFACT IN NMR PICTURE

摘要

PROBLEM TO BE SOLVED: To remove an artifact by a base line error without increasing scanning time by reversing polarity of signals every other one among nuclear magnetic resonance(NMR) echo signals. SOLUTION: An NMR signal generated by an examince is captured by a receiving coil 152B, and is impressed on an attenuated signal amplifier 207 through a front end amplifier 153. Its output is hybridized with a carrier wave signal of a line 201 by a down converter 208, and a difference signal is hybridized with a reference signal of 2.5MHz of a line 204. A phase of the carrier wave signal of the line 201 is controlled by a frequency synthesizer 200. This phase is changed in the middle of a high speed spin echo pulse train, and when signals every other one among NMR echo signals are received, the carrier wave signal of the line 201 is reversed. Then, polarity of the NMR echo signals is reversed by output 212 of the down converter 208. The output 212 is digitalized by an A/D converter 209, and is processed by a digital detector and signal processing device 210.