Fig 1.
Deuterium spectrum of the OMG phantom.
Deuterium spectrum of the spherical phantom containing 4.3 mmol/l OMG and distilled water. We assume a natural abundance of deuterium of 0.0156%. The chemical shift was determined to 3.51 ± 0.01 ppm. From a comparison of the peak areas, a degree of deuteration of 2.9 ± 0.1 deuterium atoms per OMG molecule could be estimated.
Fig 2.
Deuterium spectra of rat 3 at different time points.
Mono-Lorentzian functions were used to separately fit the different peaks. The water peak serves as internal reference and was set to 4.8 ppm. A Before the injection. The natural abundant deuterium in water is visible. B 170 s after the injection. The water and OMG signals are visible. C 55 minutes after the injection. Both peaks are visible, but the OMG signal shows a decreased amplitude.
Fig 3.
Time evolution of the signal amplitudes in the deuterium spectrum.
Signal amplitudes of the different peaks in the deuterium spectrum are shown for the whole time course of the experiment (result from rat 3). The concentration of 2H within both chemical environments (water and OMG) is given. The concentration of OMG itself can be obtained by dividing the data by its degree of deuteration, which is 2.9. The injection of OMG took place at t = 200 s and was followed by a steep increase of the glucose signal. The washout of OMG was fitted with a mono-exponential function with offset, taking into account the data from its maximum (at t = 368 s) until the end.
Table 1.
Washout rates of OMG in vivo.
Fig 4.
Chemical shift imaging of the rat leg (results from rat 3).
A Position of the grid relative to the leg and approximate position of the coil. The image was acquired with a T2 weighted turbo spin echo sequence and shows the metastases in the upper right half of the grid. The image represents a 1 mm thick slice within the CSI volume. B The deuterium spectra show an inhomogeneous intensity distribution due to the sensitivity profile of the loop coil, yet the OMG and water peak are clearly visible and distinguishable.