Publication:

Comparison of preoperative high resolution computerized tomography of temporal bone with intra-operative findings in patients with cholesteatoma

Background Aim was to study the correlation between high resolution computed tomography (HRCT) scan and intraoperative findings during surgery in cases of chronic otitis media with cholesteatoma.

Methods This was a descriptive study conducted on 72 patients with acquired cholesteatoma at Govt TD Medical College, Alappuzha for a period of 18 months. All the patients were subjected to HRCT of the temporal bone. Radiological correlation was done with the intra-operative findings. Sensitivity, specificity, positive and negative predictive values were calculated.

Results Total 24 (33.3%) patients had holotympanic cholesteatoma, 21 (29.2%) had involvement of the attic alone and 16 (22.2%) had attic and antrum involved. 100% correlation was found with bony wall erosions, whereas 96.9% and 75% sensitivity were noted in incus and stapes erosions respectively. 100% specificity was obtained in facial canal and sinus plate erosion, while a specificity of 96.9% in tegmen erosion and 98% in were seen in malleus erosion. By chi square test the difference in correlation was not significant (p value>0.01). Good correlation was seen for lateral semicircular canal fistula. Contrast CT is more specific, but MRI with diffusion weighted sequences is the best in imaging cholesteatoma, especially residual lesions.

Conclusions Good correlation was found between HRCT scan and intra-operative findings in cases of cholesteatoma in relation to bony wall erosion of the surrounding structures. CT scan alone cannot differentiate soft tissue masses.