Technical questions about MRI and CT scanning

1) For MRI, does the computer automatically avoid Nyquist violations? I understand that if you set the FOV smaller than the object, that Nyquist ghosting will occur, but other than that, what about sampling rate violations?

2) If a CT image is 256 x 256, whats the minimum resolution that can be achieved and/or what parameters does it depend on? Does the computer tell you what it is, or does the radiologist have to compute it himself or what? Basically I need a math equation to calculate resolution for CT. I'd like to have one for MRI too.

3) Does Nyquist affect CT per se? How does the Nyquist criterion fit in?

4) I'm assuming that Nyquist affects MRI only in the FOV/wrap around phenomenon. Is there another facet of MRI besides this in which Nyquist is crucial?

 

where the hell is docxter? I come here one day and there's a furious firefight discussing the quantum physics behind MRI and the next week not a soul on this board understands the technical issues involved?