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Helium [...] is critical to [...] MRI scanner Is that still the case, now that high-temperature superconductors are available, which work just fine while being

by aexaey 10y ago

Helium [...] is critical to [...] MRI scanner Is that still the case, now that high-temperature superconductors are available, which work just fine while being cooled with much cheaper liquid nitrogen instead of requiring liquid helium?

hangsi 10y ago
I can only guess that the price of replacing an MRI scanner is more than the expected difference in operating cost of nitrogen vs helium. Everything I know about MRI suggests that the machine itself is fairly pricy.
- pg_is_a_butt 10y ago
  I can only guess that you don't understand that after there is no more helium, the operating cost of helium doesn't exist either. idiot.
- akiselev 10y ago
  Not at all. MRI machines have huge start up costs but that doesn't mean they cost any less to run because making and storing liquid helium is orders of magnitude more expensive than liquid nitrogen. According to [1], for a new MRI from the manufacturer, it costs about $2 million for startup costs (capex and training) and another $2.5 million over the next 5 years for operating costs. Considering these things easily last 20-30 or more years the lifetime cost of an MRI will be an order of magnitude greater than the acquisition cost. Don't know how accurate this document is but it fits my experience of about $1 mil start up with $0.5-1 million per year operating costs. [1] http://proimagingservices.com/wp-content/uploads/2014/10/How-Much-does-it-Cost-to-Operate-an-MRI.pdf http://proimagingservices.com/wp-content/uploads/2014/10/How...
  - tomw2005 10y ago
    I have a higher up comment but cryogen free magnets exist now. They still need water and electricity but much cheaper than the cost of helium (ant the cost of the nitrogen around the helium).
  - lostlogin 10y ago
    Just to add to this good comment. MR scanners are generally (here in New Zealand) considered to have a lifetime of 10 years. Some scanners use liquid nitrogen and liquid helium for cooling. The use of compressors to reuse the helium that boils off has dropped helium use dramatically, meaning refills are now uncommon and occur every year or two.
pja 10y ago
It’s not as simple as that. Wikipedia says: Some cuprates have an upper critical field of about 100 tesla. However, cuprate materials are brittle ceramics which are expensive to manufacture and not easily turned into wires or other useful shapes. Also, high-temperature superconductors do not form large, continuous superconducting domains, but only clusters of microdomains within which superconducting occurs. They are therefore unsuitable for applications requiring actual superconducted currents, such as magnets for magnetic resonance spectrometers. IOW, we don’t have a high temperature superconducting material that’s suitable for use in an MRI scanner yet.
- arijun 10y ago
  It seems there is High temperature superconducting wire entering the market: https://en.wikipedia.org/wiki/Superconducting_wire#HTS.28High_Temperature_Superconductor.29_Wire https://en.wikipedia.org/wiki/Superconducting_wire#HTS.28Hig...
  - akiselev 10y ago
    That's still just cuprate superconductors except flattened inside of a metal tube. It's still expensive, inflexible, and for reasons to do with the SC physics, behave differently than the kind of Type 1 superconductors needed for MRIs and NMRs (high temperature superconductors are Type 2 and are a drastically different phenomenon).
- flubert 10y ago
  >we don’t have a high temperature superconducting material that’s suitable for use in an MRI scanner yet. But I think we are getting closer all the time... http://www.superpower-inc.com/content/high-field-magnets http://www.superpower-inc.com/content/high-field-magnets
Aelinsaar 10y ago
Most of the MRI machines in existence use Helium, and they're expensive machines, unlikely to be replaced until they must be.
tomw2005 10y ago
Do you know what is even cheaper than using Helium? Using cryogen free magnets: http://www.mrsolutions.com/news-events/news-item/mr-solutions-announces-first-installations-second-generation-cryogen-free-magnet-technology-increased-scientific-capabilities-preclinical-mri/ http://www.mrsolutions.com/news-events/news-item/mr-solution... Also: http://www.oxford-instruments.com/products/cryogenic-environments/superconducting-magnet-systems/cryogen-free-magnets http://www.oxford-instruments.com/products/cryogenic-environ...
flubert 10y ago
There are Type 1 superconductors (the first that were discovered), and those have the magnetic properties that are more useful creating MRI type fields. There have been breakthroughs in Type 1 superconductors and I believe GE is making an MRI using Hydrogen at 20 Kelvin for the cryogen. Although I couldn't find much more than this patent in a quick search: https://www.google.com/patents/US20130104570 https://www.google.com/patents/US20130104570 ...and then there are Type 2 superconductors, of with the High Temperature (HTS) variety have been popular. There have been steady advancements in those materials, and someday there will be an MRI machine based on HTS materials. See the link to SuperPower below as well.

by aexaey 10y ago

hangsi 10y ago

I can only guess that the price of replacing an MRI scanner is more than the expected difference in operating cost of nitrogen vs helium. Everything I know about MRI suggests that the machine itself is fairly pricy.

pg_is_a_butt 10y ago
I can only guess that you don't understand that after there is no more helium, the operating cost of helium doesn't exist either. idiot.
akiselev 10y ago
Not at all. MRI machines have huge start up costs but that doesn't mean they cost any less to run because making and storing liquid helium is orders of magnitude more expensive than liquid nitrogen. According to [1], for a new MRI from the manufacturer, it costs about $2 million for startup costs (capex and training) and another $2.5 million over the next 5 years for operating costs. Considering these things easily last 20-30 or more years the lifetime cost of an MRI will be an order of magnitude greater than the acquisition cost. Don't know how accurate this document is but it fits my experience of about $1 mil start up with $0.5-1 million per year operating costs. [1] http://proimagingservices.com/wp-content/uploads/2014/10/How-Much-does-it-Cost-to-Operate-an-MRI.pdf http://proimagingservices.com/wp-content/uploads/2014/10/How...
- tomw2005 10y ago
  I have a higher up comment but cryogen free magnets exist now. They still need water and electricity but much cheaper than the cost of helium (ant the cost of the nitrogen around the helium).
- lostlogin 10y ago
  Just to add to this good comment. MR scanners are generally (here in New Zealand) considered to have a lifetime of 10 years. Some scanners use liquid nitrogen and liquid helium for cooling. The use of compressors to reuse the helium that boils off has dropped helium use dramatically, meaning refills are now uncommon and occur every year or two.

pja 10y ago

It’s not as simple as that. Wikipedia says: Some cuprates have an upper critical field of about 100 tesla. However, cuprate materials are brittle ceramics which are expensive to manufacture and not easily turned into wires or other useful shapes. Also, high-temperature superconductors do not form large, continuous superconducting domains, but only clusters of microdomains within which superconducting occurs. They are therefore unsuitable for applications requiring actual superconducted currents, such as magnets for magnetic resonance spectrometers. IOW, we don’t have a high temperature superconducting material that’s suitable for use in an MRI scanner yet.

arijun 10y ago
It seems there is High temperature superconducting wire entering the market: https://en.wikipedia.org/wiki/Superconducting_wire#HTS.28High_Temperature_Superconductor.29_Wire https://en.wikipedia.org/wiki/Superconducting_wire#HTS.28Hig...
- akiselev 10y ago
  That's still just cuprate superconductors except flattened inside of a metal tube. It's still expensive, inflexible, and for reasons to do with the SC physics, behave differently than the kind of Type 1 superconductors needed for MRIs and NMRs (high temperature superconductors are Type 2 and are a drastically different phenomenon).
flubert 10y ago
>we don’t have a high temperature superconducting material that’s suitable for use in an MRI scanner yet. But I think we are getting closer all the time... http://www.superpower-inc.com/content/high-field-magnets http://www.superpower-inc.com/content/high-field-magnets

Aelinsaar 10y ago

Most of the MRI machines in existence use Helium, and they're expensive machines, unlikely to be replaced until they must be.

tomw2005 10y ago

Do you know what is even cheaper than using Helium? Using cryogen free magnets: http://www.mrsolutions.com/news-events/news-item/mr-solutions-announces-first-installations-second-generation-cryogen-free-magnet-technology-increased-scientific-capabilities-preclinical-mri/ http://www.mrsolutions.com/news-events/news-item/mr-solution... Also: http://www.oxford-instruments.com/products/cryogenic-environments/superconducting-magnet-systems/cryogen-free-magnets http://www.oxford-instruments.com/products/cryogenic-environ...

flubert 10y ago

There are Type 1 superconductors (the first that were discovered), and those have the magnetic properties that are more useful creating MRI type fields. There have been breakthroughs in Type 1 superconductors and I believe GE is making an MRI using Hydrogen at 20 Kelvin for the cryogen. Although I couldn't find much more than this patent in a quick search: https://www.google.com/patents/US20130104570 https://www.google.com/patents/US20130104570 ...and then there are Type 2 superconductors, of with the High Temperature (HTS) variety have been popular. There have been steady advancements in those materials, and someday there will be an MRI machine based on HTS materials. See the link to SuperPower below as well.