生体試料用改良型NMR プローブの作製と評価

We have constructed NMR signal detectors （probes） to measure the NMR spectra of living organs and tissues kept under physiological conditions. The probes consisted of non-magnetic aluminum alloy cylinder to support the detection coil made of cupper, mounted on a Teflon plate with acrylics plates and rods, however, the recovery time to the static magnetic field after turning off of the pulsed gradient field was more than 10 times longer than that of the micro-MRI probe available commercially.
The re-design of our probes, such as acrylics cylinder to support the coil, together with readjustment of the eddy current compensation circuit, provided us the recovery time to the static field less than 1 msec, making it possible to measure the diffusion coefficient of Na+ ion using the pulsed field gradient spin echo method. The diffusion coefficient of Na+ ion in skeletal muscle isolated from bullfrog was 0.6 time larger than that in Ringer’s solution, suggesting a high viscosity in the skeletal muscle.