Clinical Values of HRCT for Diagnosis of Incus Dislocation

Abstract

BACKGROUND: The quick and accurate radiologic evaluation is essential to minimize the sequelae of temporal bone trauma. High resolution computed tomography(HRCT) is regarded as a method of choice in the evaluation of the head trauma including temporal bone fractures. Although the diagnosis of ossicular dislocation with HRCT has been described, we could find only one report on the usefulness of coronal sections in the diagnosis of lateral displacement of the incus. OBJECTIVES: The purpose of this study is to evaluate the usefulness of a recently reported radiologic sign, named the "Y" sign, for the diagnosis of lateral dislocation of the incus on the coronal HRCT sections of the temporal bones. MATERIALS AND METHODS: We retrospectively reviewed the axial and coronal HRCT sections of 13 cases who the laterally dislocated incus was confirmed operatively. RESULTS: In the axial HRCT sections, abnormal ice cream cone was shown in only 3 cases, but normal ice cream cone was shown in 10 cases. In the coronal HRCT sections, the Y-sign was shown in 11 cases-open Y-sign: 3 cases, closed Y-sign: 8 cases, in contrast, only 2 cases did not shown Y-sign. CONCLUSION: The Y-sign in the coronal sections is more correlated with the dislocated incus than with abnormal ice cream cone configuration in the axial sections. So, the Y-sign seems to be very useful in the diagnosis of the dislocated incus.