ear, nose, and throat disorders
Mastoiditis
Diagnosis of Mastoiditis
A doctor's evaluation Computed tomography Doctors typically base the diagnosis on the person's symptoms. Doctors usually do computed tomography (CT) to confirm the diagnosis. To identify the bacteria causing the infection, doctors take samples of the discharge from the ear so that the bacteria in the discharge can be grown in a laboratory (cultured). If people do not have a discharge, doctors use a needle or make an incision in the eardrum and take a sample of the fluid from the middle ear. 