hi wbb, re lesions on mri, when they dx they would need to demonstrate 'dissemination over time' ie new lesions and old lesions indicating more than one neurological episode. if you have no enhancing lesions under contrast they would all be basically 'old' and therefore may not even be related to your current physical symptoms. there is a notorious disconnect between brain lesion patterns and physical symptoms in ms patients.
as for nutrition, yes ms patients tend to have one nutritional profile and healthy controls another. people with wildly different habits can end up in similar suboptimal boats nutritionally. the manifestation of illness varies with genetics and life history. for ms patients, both sick and healthy profiles are within 'normal' ranges so testing becomes a little more challenging than a yes/no thing (such as testing positive or negative for a specific infection for example). however, ms patients are consistently lower in certain vital nutrients, compared to their healthy counterparts.
i have a background blurb and list of nutrient targets here if you care to read more. i update the content regularly to include new info. regimens-f22/topic2489.html#p15460
there are lots of theories out there on ms nutrition, this is just one of many.
hope that helps!