Will a ent always need a ct scan to address a csf leak?

Probably: Depends on symptoms or signs. You should see them first in case they can diagnose another reason. You may need a special ct scan where they inject a unique dye into your CSF compartment via your back. Ent will need to localize the location (ie ear/sinus/side) and size of the defect to assess what to do. Still there may be other reasons for your symptoms such as a hematoma or other sources. See ent

Usually: A CT, although not diagnostic of a CSF leak, is always helpful in assessing the anatomy in order to assess the skull base either for CSF drainage from the ear or nose.