I read through wikipedia quickly to give you an answer.
Disney 3D is usually played at 144 frames per second(72 image frames and 72 black frames fed to each eye per second).
Uses a single projector(Christie, Barco or NEC DLP) - and requires passive circularly polarized glasses
"A single projector can also be used in conjunction with a simple adapter in the front (a single-cell LCD screen that acts as a quarter-wave retarder, also known as a zscreen) that rotates the polarity of projector's light output several times per second to alternate quickly the left-and-right-eye views." aka "push-pull electro-optical modulator"
The size of the screen may limited compared to IMAX, they both have advanced technology, but the difference in projectors is questionable, some may be identical visually, but I'm guessing IMAX may have a better picture. I've never seen either in theaters in person.
IMAX may use two different digital 3D projectors nationwide.
Either this: "two 2K-resolution Christie projectors with Texas Instruments Digital Light Processing technology alongside parts of IMAX's proprietary system.per projector, which produces 3D on a 2D screen, and operates at 96 frames per second." -wikipedia
Or: Sony SXRD
From what I see, those 4k are available in AMC and Muvico theatres.
also see - http://broadcastengineering.com/hdtv/amc_theatres_sony_projectors/
IMAX requires LCD shutter glasses