There has been a big push in MRI to try and reduce cost, increase reliability, and increase the number of receiver channels. The cabling has become a major problem for both cost and reliability. At least in the US, this is all regulated to the nth degree, and the signals are small, so high performance cables are needed. The combination of these factors results in high cost. Hence, the push to move more electronics from the equipment room into the scan room (inside the Faraday cage), and move the receivers, including the high speed A/Ds into the bore, with a minimum number of cables out.
There is also a push to move power electronics into the scan room, or even on the magnet. Even though there are places on the outside of the magnet where ferrite won't saturate, it's not allowed because of safety concerns around maintenance. Interference is another big problem, but one way to address that is the patent I referenced above.
John