Yeah, I know they’re getting cheaper, and they’re sophisticated pieces of equipment, but I’m sure that there’s a few components in them which keep them from being as common as the blood pressure machines in grocery stores.
Supercooled magnets and large copper excitation coils. Wiki article here points out that the magnet is the most expensive part of the system.
The direct cost of the equipment is just one thing, but then you also have to include power usages such as electricity, and also the cost of chilled water cooling - chilled water is a more expensive commodity than electricity.
Add to that the cost of the suitable premises, which must be constructed so that small eddy currents do not circulate in the structural metalwork (this tends to reduce the resolution of the imager) and then the cost of things such as computor equipment that is used to enhance images, and also add on the cost of enough trained staff - and the cost of the training of those staff, the whol costs of a MRI scanner are very much greater than the equipment itself.
Because they cost a lot.
They will be cheaper when everyone has one and you can buy them at Walmart.
I’m sure the liquid helium and liquid nitrogen they use is considerably more pricey than chilled water.
… and which can be charged at prices which can be several times higher than those of a “not special for medical uses” computer, even though they’re the same or less…
Dad was the Purchasing Manager for a hospital, which he got to buy the initial equipment for. He was told he had to buy all electric or electronic appliances from brands X, Y or Z, which were Authorized Suppliers. He sent lists of what he needed to them and got the offers back. When he got the first offer, he thought there must have been a mistake, but then he got the other two.
And then he called a friend in the factory where he’d previously worked - which happens to make all that kind of stuff - and placed several special orders. Things like “50 TVs without the channels card”, which is what a computer monitor was at the time. Because they weren’t labeled “for medical use”, each piece of equipment cost between 1/3 and 1/10 of the price given by the authorized sellers (both the factory and the authorized sellers were, in theory, giving him “bulk” prices like a store would get). And the items that absolutely killed Dad were… the ones that his old factory made for those other brands! He’d been the production manager, he knew perfectly well the (absolute lack of) difference between the “medical” models and the regular ones.
Especially the liquid helium. Liquid nitrogen is fairly cheap. Hell, I used to keep a gallon of that in my office!
Keeping a piece of equipment within a few degrees of absolute zero is an expensive proposition.
Thankfully, much less helium needs to be used than nitrogen. Our lab refills the liquid nitrogen on our superconducting magnets weekly, while the helium only gets filled monthly.
And don’t forget the data processors and magnet shims that are required for these things. Forget image enhancement, these pieces of equipment use computers that are the size of two large refrigerators to keep the magnetic feilds just right, limit interference and collect data. You might get away with data processing on a standard PC (though they usually use unix work stations.), but aquiring the FID’s is a phenomenal challenge. (Technically, I don’t work with MRI’s but I work with NMR’s and they are essentially the same thing.)
Heh. I remember when MRIs were called NMRs!
But then lotsa patients refused to get a test with the word “nuclear” in it. :rolleyes:
They’re having a sale at the Danbury CT Walmart - “Get a free MRI machine for every Particle Accelerator you buy. Offer ends midnight 5/10/07.”
Still are called that in pharmaceutical R&D. It was only recently that I knew of the parallel between our NMR lab and MRI. Silly.
I read that these days magnetic resonance imagers cost a million dollers per Tesla.
Do US hospitals have “Nuclear Medicine” departments? Or is the place where GFRs etc. are done called something else?
No, we have “nuclear medicine”. Tho we usually refer to it as “unclear medicine” in front of patients.
Other industries are the same way. A friend was telling me about the time the monitor on one of the CNC machines went out where he worked. They called the machine manufacturer, who wanted several thousands of dollars for a new one (not including installation costs). When they tore the machine apart and found who made the monitor and contacted that company the price was only a few hundreds of dollars.
Of course, it may be quite a bit cheaper to buy one used.
Yeah, but the scale is vastly different. Have you *seen *the tubes they use for people?