Figure 3 – Phase variation during 2H MRS interleaved with a 7-slice spin-echo MRI. The phantom consisted of three bottles containing ~0.1% D2O and various amounts of DMSO-D6 (~0.02 – 0.05%). A small (0.5 mL) phantom containing pure D2O served as an external off-resonance reference signal. (A) Phase variation in the absence of a phase lock. (B) In addition to the strong linear phase roll there is also a smaller sequence-dependent phase modulation. (C) In the presence of a phase lock, each spectrum has an identical phase. The 1D spectra shown in (A) and (C) are extracted from repetition 200.

Figure 1 – (A) Four channel interleaved mixer. Inputs for the mixer are from their respective preamplifiers. The 1H signal is applied to one arm of the RF switch. The 2H signal is sent to an RF mixer and upconverted to 170MHz by mixing with the 144MHz LO. The upconverted signal is filtered to remove the unwanted sideband, amplified and sent to the RF switch. The PPG controls when each nucleus is sent to the scanner’s 1H receiver. (B) Each channel is isolated from outside interference and each other by using a dedicated RF shielded enclosure built onto the board.