https://www.peertechz.com because of the high keratin content. Thus, whereas, echoplanar imaging (EPI-DWI) has the disadvantages of lower spatial resolution and the presence of artefacts due to the proximity of bone [8,18], the introduction of non-echo-planar AbstractBackground: Diffusion-weighted magnetic resonance imaging (DWI) is an alternative to second-look surgery for the detection of cholesteatoma.Purpose: To assess the utility of DWI with echo-planar (EPI-DWI) and non-echo-planar (PROPELLER) sequences for the diagnosis of primary and recurrent cholesteatoma. Materials and methods:A prospective study of 33 ears, 21 with previous cholesteatoma surgery. Twelve patients were asymptomatic, with 4 showing signs suggestive of cholesteatoma in previous CT scans. The MRI protocol was: axial and coronal T1-weighted and T2-weighted imaging, and diffusionweighted sequences by both EPI-DWI and PROPELLER techniques. The results were correlated with the clinical examination and subsequent surgical fi ndings. Ten patients undergoing ear surgery for other reasons were included as negative controls. Results:The diagnostic accuracy was calculated with the 22 patients who underwent surgery and the negative controls. Both diffusion-weighted sequences showed a specifi city of 100%. The sensitivity of PROPELLER was 95%, compared to 20% for EPI-DWI. The latter showed non-specifi c imaging with bone artefacts, thus making impossible to confi rm or exclude the diagnosis. The PROPELLER technique yielded one false negative, compared with 16 by EPI-DWI. Both techniques gave a false negative in one case of a primary cholesteatoma. A positive result was obtained in two patients with no clinical suspicion of recurrence. Conclusions:In contrast to EPI-DWI, PROPELLER is a reliable technique for diagnosing cholesteatoma. As positive results were found in asymptomatic patients, we recommend regular monitoring by PROPELLER, even in the absence of clinical fi ndings.