Differential Diagnosis of Middle Ear Inflammatory Diseases by MRI Findings.

Although computed tomography can reveal a soft tissue mass in middle ear diseases as an area of increased density, it cannot differentiate cholesteatoma from other inflammatory tissue. We prospectively studied 30 patients with various middle ear inflammatory diseases, including inflammatory granulation tissue, cholesteatoma and cholesterin granuloma with magnetic resonance imaging (MRI) with or without Gd-DTPA enhancement. Cholesteatoma and inflammatory granulation tissue showed intensity ranging from low to high on Ti-weighted images and from high to very high on T2-weighted images. However, cholesteatoma showed either no enhancement or ring enhancement on MR imagings with Gd-DTPA, and it could be differentiated from the Gd-DTPA-enhanced inflammatory granulation tissue. Cholesterin granuloma showed very high intensity on both T1 and T2-weighted images. Therefore, MRI with Gd-DTPA is considered to be useful in the differential diagnosis of these middle ear diseases.