Video card might be tricky since he's using a Sun box of some type; he'd have to look into that more with his vendor I bet.
DICOM? I am unfamiliar with this but it seems to apply to very little related to displaying medical information:http://en.wikipedia.org/wiki/DICOM
The closest I see is PS 3.14 -2011, Page 12, 7.1 GENERAL FORMULAS which mainly talks about how bright stuff should be for light boxes and CRTs though then goes on to printers: http://medical.nema.org/Dicom/2011/11_14pu.pdf
It seems to be more about a data format for the interchange of medical imaging data. I do see that Eizo is pimping that their RadiForce line is adjusted at the factory to have those brightness characteristics and it has software that helps, but I don't know that it will be of help to the OP since he's running some closed system (?) and the software is probably Windows-based. With the bundled RadiCS LE quality control software installed, a built-in backlight sensor periodically checks for brightness irregularities of RadiForce MX-Series monitors.
So basically the characteristic you want for a "medical" monitor is to brighten the dark areas. The OP's old monitor doesn't seem to conform to that standard/washing out feature nor do the two that were recommended. And hell, they got a ton of things they adhere to:
CE,CB, BSMI, PSB, SASO, C-tick, e-standby, KC, UL/cUL, FCC-B (including ICES003), UL CoC, Mexico Energy, GOST-R/Hygienic, UkrSEPRO, Erp, CCC, ENERGY STAR®, China Energy, EPEAT Silver, WEEE, RoHS, SVHC list
I submit that the OP didn't know what "medical grade" really meant. Which is fine, I mean, I didn't know until you just posted and it's been an interesting learning experience. Medical places get sold on high pixel count and washed out blacks which makes sense, it's just funny that you pay a premium for that kinda stuff.