Just had mri of brain due to headaches, dizziness, other neuro, plus nausea. was normal. can i trust radiologist to spot everything? thick csf later!

Hopefully: Hopefully your doc sent you to a radiologist that he/she trusts to see what he/she wants to exclude. The MRI should be very good at ruling out significantly dangerous structural problems in the brain. Not sure what you mean by thick CSF later.

MRI normal: Short answer, yes. What many people don't realize is that imaging studies predominately look at anatomy, not function. If a process does not change the structure, or cause inflammation, it cannot be seen on any test. We do imaging studies to make sure that there is not a tumor or other macroscopic change (infection, ms) that is causing symptoms.