(A) Directly detected spectrum of 129Xe in the encoding
coil obtained with one π/2 pulse and one signal acquisition. (B)
Directly detected spectrum of 129Xe in the detection coil obtained
with one π/2 pulse and one signal acquisition. (C) 2D time domain
free induction decay (FID) data of the 2D remote experiment. Both the direct
and indirect dimensions were obtained by measuring 128 points with a dwell
time of 50 μs. No signal averaging was necessary for the acquisition. The
indirect dimension contains point-by-point detected FIDs, which are encoded in
the encoding coil, and after signal transfer, remotely detected in the
detection coil. (Inset) One slice of the indirect spectrum FID. The
unencoded 129Xe adds an apparent baseline offset to the indirectly
detected FID, which is removed during processing. (D) The remote
detection spectrum is one slice taken at the maximum gas peak of the direct
dimension along the indirect dimension of the 2D data in C. The
spectrum reconstructs the spectral information in the encoding coil although
it is measured in the detection coil. Comparison of A and D
shows that the remote detection experiment shows an SNR improvement of a
factor of ≈10 times, consistent with the SNR difference between the direct
spectra in A and B taken in the encoding and detection
coils, respectively.