Do i have to get some blood tests before doing a thoracic spine mri without dye?

Not usually: There is no need to get a blood tests for a non-contrast spine mri. However, if there is a chance that contrast might be used during the test, it's probably easier to get a simple kidney function test before having the scan, rather than having to come out, get the test and reschedule.

Typically not: Because there is no dye being used, lab tests are not usually required for the scan itself. That being said, many of the conditions that would prompt a doctor to request a thoracic MRI would also lead him or her to request lab tests as well.