To determine the diagnostic performance of diffusion-weighted magnetic resonance imaging in the assessment of patients with suspected, but not clinically evident, cholesteatoma.

A retrospective analysis of a prospectively collected database of non-echo-planar diffusion-weighted magnetic resonance imaging studies (using a half-Fourier single-shot turbo-spin echo sequence) was conducted. Clinical records were retrospectively reviewed to determine indications for imaging and operative findings. Seventy-eight investigations in 74 patients with suspected cholesteatoma aged 5.7–79.2 years (mean, 41.7 years) were identified. Operative confirmation was available in 44 ears. Diagnostic accuracy of the imaging technique was calculated using operative findings as a ‘gold standard’. Sensitivity of the investigation was examined via comparison with clinically evident cholesteatoma.

The accuracy of diffusion-weighted magnetic resonance imaging in assessment of suspected cholesteatoma was 63.6 per cent. The imaging technique was significantly less accurate in assessment of suspected cholesteatoma than clinically evident disease (p < 0.001).

Computed tomography and diffusion-weighted magnetic resonance imaging may be complementary in assessment of suspected cholesteatoma, but should be used with caution, and clinical judgement is paramount.

To determine whether a threshold apparent diffusion coefficient value may help to differentiate laryngeal carcinomas from benign lesions.

Fifty-three patients with laryngeal masses were recruited; four of them were excluded because of susceptibility artefacts. In the remaining 49 patients, the pathological results showed 32 laryngeal carcinomas and 17 benign lesions. The diagnostic value of diffusion-weighted magnetic resonance imaging for the identification of malignant lesions was determined. In addition, the agreement between diffusion-weighted magnetic resonance imaging and histopathology was assessed. Moreover, the sensitivity, specificity, and negative and positive predictive values of the apparent diffusion coefficient in detecting benign and malignant lesions were analysed. An apparent diffusion coefficient histogram was also produced.

An apparent diffusion coefficient value of 1.1 × 10−3 mm2/second produced the best result when used as the cut-off point to differentiate malignant from benign masses.

An apparent diffusion coefficient threshold of 1.1 × 10−3 mm2/second is optimal for distinguishing laryngeal carcinomas from benign lesions. Apparent diffusion coefficient values were lower for patients with laryngeal carcinomas than for those with benign lesions.