Is preoperative computed tomographic density measurement of soft tissues helpful in the diagnosis of cholesteatoma?

We undertook to verify the usefulness of computed tomography Hounsfield units (HU) in differentiating cholesteatoma from inflammatory tissue.

In 91 enrolled cases, the lesions were classified according to the gross pathology, and the specific locations of each lesion were documented by 1 surgeon within 1 day after the operation. The densities in HU of cholesteatoma and non-cholesteatoma lesions were retrospectively measured 3 times by the same examiner, and the difference between the two groups was analyzed. The interobserver reliability among the 3 examiners was assessed to verify the confidence level of the HU measurements in preoperative detection of cholesteatoma.

The mean HU values of cholesteatoma were 35.7 to 66.6 HU, and those of non-cholesteatoma lesions were 32.9 to 51.3 HU. A general linear model-repeated-measures analysis of variance did not show any significant difference between the cholesteatoma and non-cholesteatoma lesions (p = 0.305). The general linear model-repeated-measures analysis of variance showed a significant difference of the measured HU levels among the 3 examiners (p = 0.021).

This study showed that the HU values on preoperative computed tomography did not suffice for the detection of cholesteatoma lesions. A clinician's physical examination together with an interpretation of computed tomography is still the "gold standard" method.