High Resolution Computed Tomography of Temporal Bone: The Predictive Value in Atticoantral Disease

To evaluate predictive value of high resolution computed tomography in atticoantral disease. We conducted a prospective observational study in 49 patients suffering from atticoantral disease at tertiary referral institute. Preoperatively, all the patients underwent unenhanced high resolution computed tomography (HRCT) of temporal bone parallel to orbitomeatal line by using multislice scanner. We evaluated presence of soft tissue attenuation, ossicular erosion, facial canal erosion, dural exposure, erosion of semicircular canal, labyrinthine fistula, erosion of scutum and tegmen tympani in CT scan. HRCT is recommended in atticoantral disease with complications. This study demonstrates the predictive value of HRCT of temporal bone as a diagnostic modality in atticoantral disease. HRCT shows 100% sensitivity (Sn) of soft tissue density detected in middle ear, aditus and attic. Specificity (Sp) was more for eustechian tube area and sinus tympani. Ossicular erosions of malleus (Sn = 90.9%, Sp = 75%), incus (Sn = 93.2%, Sp = 80%), stapes (Sn = 78.8%, Sp = 68.8%) were detected. Erosion of scutum (Sn = 94.1%, Sp = 80%), tegmen (Sn = 66.7%, Sp = 100%), sinus plate (Sn = 100%, Sp = 97.9%), facial nerve canal (Sn = 75%, Sp = 100%), semicircular canal fistula (Sn = 80%, Sp = 97.7%) and cochlear promontory fistula (Sn = 50%, Sp = 97.9%) were evaluated. HRCT temporal bone helps to evaluate disease extent and involvement of surrounding structures. Hence it helps in deciding surgical approach and also prevents impending complications.