Is an MRI or CT scan without contrast useful to define a preauricular sinus? 3 month evolution; spontaneous drainage of large abscess next to ascending margin of helix. Inflammation did not totally resolve. Now slight pain and heaviness in both ears and

A . A non-contrast MRI will be able to characterize the lesion and demonstrate the extent. It will be far more helpful than ct in this regard. It may give you some piece of mind if a diagnosis of sebaceous cyst can be made.
No. Radiology studies do not help. All you see is inflammation/pus. An experienced surgeon will have to find and excise the entire tract and cyst or it will come back.