It's a few years that I have had some strange feeling/problem in the
zone around/below the xiphoid bone and I would like that area examined.

I want to decide between CT and MRI. I am kinda aware of what is CT scan
since I have done one for the head in the past but I don't know how MRI
works. Today I tried to read a lot about MRI but there is something I
still don't understand:

I know that CT scan takes the images of a lot of sequential parallel
slices, i.e. 15 or more... while everywhere I read it seems that MRI
takes only 3 slices in 3 orthogonal planes centered in a point. Is that
correct? Well, that seems incredibly inferior to CT... what if I none of
the 3 planes intersects the zone where the problem really is?

Also I am looking at this page:
http://www.wecaremedicalmall.org/
e.g. see this excerpt:
----
Tennessee MRI - CT Scan Locations/Services/Languages
Tennessee Prices
MRI - $460
MRI - With contrast $510
CT scan - $270
CT scan with contrast - $370
Three location full body CT scan (abdomen, pelvic, chest) $575
Five location full body CT scan (head, neck, abdomen, pelvic, chest) $825
----
Does this mean that the MRI can only be "single location", cannot be
done full-body? Or is it always full-body with three orthogonal
projection planes centered in the point the patient chooses?

TIA