Is there a signal-to-noise problem if you don’t do hyperpolarization, and just give someone an isotopically enriched molecule
Yes.
17O seems like a good try for that
MRI with oxygen-17 has been done. Here’s a study from 1990. And here’s a more recent paper which mentions some reasons it hasn’t been widely used, including:
low inherent NMR sensitivity
short relaxation time
Yes.
MRI with oxygen-17 has been done. Here’s a study from 1990. And here’s a more recent paper which mentions some reasons it hasn’t been widely used, including:
low inherent NMR sensitivity
short relaxation time