TABLE 1.
Summary of acquisition parameters in HP [1-13C]pyruvate imaging animal studies and human studies. Note that while the voxel dimensions changed between Experiment A and B for the human studies, the voxel volumes were fixed so we could compare SNR across experiments.
| (a) Acquisition parameters in animal Study | |||
|---|---|---|---|
| Experiment A | Experiment B | Experiment C | |
| Pyruvate | 2D MS-GRE FOV 8×8×16.8 cm3, resolution 2.5×2.5×21 mm3, TR 100 ms |
||
| Lactate | 2D MS-GRE resolution 5×5×21 mm3, TR 100 ms |
3D MS-bSSFP resolution 5×5×21 mm3 |
|
| Bicarbonate | 3D MS-bSSFP resolution 7.5×7.5×21 mm3 |
2D MS-GRE resolution 7.5×7.5×21 mm3, TR 100 ms |
3D MS-bSSFP resolution 7.5×7.5×21 mm3 |
| ALL | Temporal resolution 2.5 s, 30 timepoints | Temporal resolution 2.8 s, 30 timepoints | |
| (b) Acquisition parameters in human brain study | ||
|---|---|---|
| Experiment/Subject A | Experiment/Subject B | |
| Pyruvate | 2D MS-GRE FOV 24×24×15 cm3, resolution 7.5×7.5×15 mm3 (0.84 cc), TR 110 ms |
2D MS-GRE FOV 31.7×31.7×16.8 cm3, resolution 6.34×6.34×21 mm3 (0.84 cc), TR 125 ms |
| Lactate | 2D MS-GRE resolution 15×15×15 mm3 (3.37 cc), TR 110 ms |
2D MS-GRE resolution 12.68×12.68×21 mm3 (3.37 cc), TR 125 ms, |
| Bicarbonate | 3D MS-bSSFP FOV 24×24×24 cm3, resolution 15×15×15 mm3(3.37 cc) |
2D MS-GRE FOV 31.7×31.7×16.8 cm3, resolution 12.68×12.68×21 mm3(3.37 cc), TR 125 ms |
| ALL | temporal resolution 3 s, 30 timepoints | |
| B1+ Mapping | 2D MS-GRE with Bloch Siegert method on pyruvate frequency FOV 45×45×9 cm3, resolution 1.5×1.5×30 mm3, slice gap = 4.5 cm, 3 slices, TR 200 ms, flip angle 8°, ωRF 4.5 kHz |
|
| (c) Acquisition parameters in human renal study | |
|---|---|
| Pyruvate | 2D MS-GRE FOV 50×50 cm2, resolution 1×1×2.1 cm3, TR 80 ms |
| Lactate | 3D MS-bSSFP FOV 46×46×33.6 cm3, resolution 1×1×2.1 cm3 |
| Bicarbonate | 3D MS-bSSFP FOV 92×92×33.6 cm3, resolution 2×2×2.1 cm3 |
| ALL | temporal resolution 3.5 s, 30 timepoints |
| (d) Common Sequence Parameters | |
|---|---|
| 2D MS-GRE | Tread 22 ms, flip angle 20° (pyruvate) or 30° (lactate and bicarbonate), 8 slices |
| 3D MS-bSSFP | Tread 3.8 ms, flip angle 60°, echo train length 64, TR 9.8 ms (bicarbonate) or 15.29 ms (lactate), 16 slices |
Notes: (a) Three experiments (A, B&C) were conducted to compare the lactate and bicarbonate signal acquired by two different sequences. In experiment A, 2D MS-GRE sequence was used to acquire pyruvate and lactate signals and 3D MS-bSSFP sequence was used to acquire bicarbonate signal. In experiment B, 2D MS-GRE sequence was used to acquire all metabolite signals. In experiment C, 2D MS-GRE sequence was used to acquire pyruvate signal and 3D MS-bSSFP sequences were used to acquire lactate and bicarbonate signals; (b) Two experiments (A and B) were conducted to compare the bicarbonate signal in the human brain using 2D MS-GRE and 3D MS-bSSFP sequences, respectively; (c) A clinical trial was conducted on a patient with RCC to demonstrate the feasibility of the MS-bSSFP sequence.