So is there image reconstruction in electron spectroscopy? Is ESR not used as much for imaging because of the limited amount of "structures" it can examine, i.e. paramagnetic or only ones containing free electron(s)? Theoretically, would there be a way to influence the _nuclear_ spin via the electron?
Hi Daniel, Thanks for the interesting question. I am not aware of any work on ESR imaging. I think the same issue we have with ESR magnetometry - broad resonance in most materials - would also impact imaging, since you wouldn't be able to reliably extract the gradient field information for the XYZ deconvolution.
@@MetrolabTechnology Sorry, it was my understanding that ESR was used for both (1) imaging and (2) sussing out the geometries and other information about certain molecular structures via something like fine, or hyperfine splitting. For the imaging, I had thought it is used primarily where there are high, or variable, concentrations of free radicals. So I was thinking that the reason why MRI is a much more "successful" imaging modality is because of the prevalence of hydrogen (as opposed to free electrons w/ ESR) in biological structures.
I stand corrected: EPR imaging does exist; it even has its own acronym, EPRI. But I wasn't entirely wrong: the resolution is limited by the spectral line width - and the strength of the gradients, of course. But I also just learned that there are post-processing techniques to reduce that line width. So there's obviously a lot of work out there that I wasn't aware of; thanks for pointing it out! As to why MRI is more widespread than EPRI: the applications of EPRI that I read about in my quick survey all concerned rather specialized research in physics, chemistry or biology. None of these have the universal clinical relevance of being able to image the soft tissue inside our body. I think that's much more important than any technical reason. Philip
@@MetrolabTechnology Interesting. No doubt though if EPRI did have the same resolution as MRI then EPRI would probably be utilized if only due to decreased cost, namely you would no longer require the superconducting magnets. Why is the spectral line wider in EPRI?
Sorry Nabil, your question got lost somehow. If it's still relevant, please feel free to re-post, perhaps with some more specifics. In any case, thanks for the compliment! Philip
