Radiology is 5 years (1yr prelim/ty + 4 years diagnostic radiology). Then an interventional radiology fellowship is 1 year. Neurointerventional is an additional 3 years (1.5-2years neurodiagnostic and 1-1.5 years neurointerventional) , but can sometimes be condensed to an additional 2 instead of 3. Neurointerventionalists usually have neurosurgeons for backup purposes. NIRs do procedures themselves for the most part unless the neurosurgeon has completed a neuroIR fellowship. Also there are special combined radiology/IR programs where you still do six years, but its 1yr prelim+3 d.rads.+2yr IR. At then end of this you are board certified for diag rads and fellowship CAQ'd for IR. There are also some combined neurology, radiology, and neuroradiology CAQ boarded programs which are 7 years total, but have their own share of problems.