Detection of middle ear cholesteatoma by diffusion-weighted MR imaging: multishot echo-planar imaging compared with single-shot echo-planar imaging.

BACKGROUND AND PURPOSE: Previous reports have shown that DWI is useful in detecting cholesteatoma. SS-EPI is the most widely used DWI technique. However, SS-EPI may have susceptibility artifacts due to field inhomogeneity in the imaging of the temporal bone region. Our purpose was to prospectively evaluate the advantage of MS-EPI for the diagnosis of middle ear cholesteatoma by comparing it with SS-EPI.

MATERIALS AND METHODS: We studied 29 patients with preoperatively suspected acquired cholesteatoma. Each patient underwent an MR imaging examination including both SS-EPI and MS-EPI by using a 1.5T MR imaging scanner. Images of the 29 patients (58 temporal bones including 30 with and 28 without cholesteatoma) were reviewed by 2 independent neuroradiologists. The confidence level for the presence of cholesteatoma was graded on a scale of 0-2 (0 = none, 1 = equivocal, 2 = definite). Interobserver agreement as well as sensitivity, specificity, and accuracy were assessed for the 2 readers.

RESULTS: Excellent interobserver agreement was shown for both MS-EPI (κ = 0.856) and SS-EPI (κ = 0.820). MS-EPI was associated with higher sensitivity (76.7%) and accuracy (87.9%) than SS-EPI (sensitivity = 50.0%, accuracy = 74.1%) (P < .05), while both methods showed 100% specificity.

CONCLUSIONS: Compared with SS-EPI, MS-EPI improves the accuracy of the diagnosis of acquired middle ear cholesteatomas.