Agreed. I am fortunate to work at a facility with a lot of talented physicist and engineers who are building the next generations of these magnets. I, the lowly life-scientist, am just surfing off their accomplishments. Occasionally I do remind them that living samples require require some delicacy though...
The issue is not the magnetic field, its the dielectric heating from the microwave-frequency radiation needed to detect nuclear spins at the higher magnetic fields. Yes, the cell-phone radiation issue has raised the question of whether other (yet undetected) phenomena can occur in cells (like changes in gene regulation/expression) in response to microwave radiation. The issue of cooking a patient is by far a bigger challenge. Patients can get waivers for high field MRIs, but the spectrometers are still not very common (mostly due to their price). Image quality can be improved by other, cheaper methods such as DNP. Most hospitals still use 2-D, black and white (X-ray style) renderings of MRi data due to their policy, level of comfortability, and in some cases law. Also, a limited number of MRi experiments are even approved for diagnostics (even the hyped fMRi/lie detector is not technically FDA approved to treat or diagnose anything). Other than an elite group of specialist physicians and medical research scientists, most clinicians probably would not be able to take advantage of the improved resolution of high field instruments unfortunately.
Agilent (Varian) has a system that is up to 16T and Bruker has systems up to almost 12T. Technically, the highest field MRI is at the NHMFL (21T at 900MHz), but it cannot accept live samples so it doesn't count...
MRi is technically just a euphemism for Nuclear Magnetic Resonance (NMR) imaging. The N was dropped because it of the obvious stigma that word possesses outside of scientific circles. We already have structures of these proteins solved by NMR. The next challenge is indeed to view these molecular systems in-vivo. I doubt that these techniques will actually make it out of the research setting. MRi's with fields higher than 3T are having trouble being approved by the FDA for clinical use. This is complicated by the fact that high field instruments are really expensive to begin with. Other scientists are working hard to advance the image quality in other ways.
The issue is not the magnetic field strength (which only aligns the nuclear spins). Instead, the major hurdle would be that microwave frequency radiation would be needed to image a person at that field strength (rather than radio-frequency) at typical MRI field strengths, thus cooking the person by dielectric heating. Also, the iron in hemoglobin is paramagnetic, not ferromagnetic. It is aligned by the magnetic field, but is not at risk of being torn out of the body. Though if you like iron shavings with your breakfast cereal...
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Agreed. I am fortunate to work at a facility with a lot of talented physicist and engineers who are building the next generations of these magnets. I, the lowly life-scientist, am just surfing off their accomplishments. Occasionally I do remind them that living samples require require some delicacy though...
The issue is not the magnetic field, its the dielectric heating from the microwave-frequency radiation needed to detect nuclear spins at the higher magnetic fields. Yes, the cell-phone radiation issue has raised the question of whether other (yet undetected) phenomena can occur in cells (like changes in gene regulation/expression) in response to microwave radiation. The issue of cooking a patient is by far a bigger challenge. Patients can get waivers for high field MRIs, but the spectrometers are still not very common (mostly due to their price). Image quality can be improved by other, cheaper methods such as DNP. Most hospitals still use 2-D, black and white (X-ray style) renderings of MRi data due to their policy, level of comfortability, and in some cases law. Also, a limited number of MRi experiments are even approved for diagnostics (even the hyped fMRi/lie detector is not technically FDA approved to treat or diagnose anything). Other than an elite group of specialist physicians and medical research scientists, most clinicians probably would not be able to take advantage of the improved resolution of high field instruments unfortunately.
Agilent (Varian) has a system that is up to 16T and Bruker has systems up to almost 12T. Technically, the highest field MRI is at the NHMFL (21T at 900MHz), but it cannot accept live samples so it doesn't count...
MRi is technically just a euphemism for Nuclear Magnetic Resonance (NMR) imaging. The N was dropped because it of the obvious stigma that word possesses outside of scientific circles. We already have structures of these proteins solved by NMR. The next challenge is indeed to view these molecular systems in-vivo. I doubt that these techniques will actually make it out of the research setting. MRi's with fields higher than 3T are having trouble being approved by the FDA for clinical use. This is complicated by the fact that high field instruments are really expensive to begin with. Other scientists are working hard to advance the image quality in other ways.
The issue is not the magnetic field strength (which only aligns the nuclear spins). Instead, the major hurdle would be that microwave frequency radiation would be needed to image a person at that field strength (rather than radio-frequency) at typical MRI field strengths, thus cooking the person by dielectric heating. Also, the iron in hemoglobin is paramagnetic, not ferromagnetic. It is aligned by the magnetic field, but is not at risk of being torn out of the body. Though if you like iron shavings with your breakfast cereal...