Colour Doppler ultrasonography of retropharyngeal abscess.

OBJECTIVE: This study was conducted to determine the capability of colour Doppler ultrasonography (CDU) in evaluating retropharyngeal abscess in children. MATERIALS AND METHODS: From July 1996 to February 1998, five children with clinical suspicion of retropharyngeal abscess were evaluated by CDU. The distance from internal carotid artery (ICA) to cervical vertebra (CV) (DICA-CV) at the upper cervical level was measured by longitudinal ultrasonography. Fifty healthy children, aged from 1 to 15 years, were recruited in the study to measure DICA-CV as control. Colour Doppler ultrasonography was used to differentiate abscess from other pathology and to detect carotid sheath invasion. Computed tomography was performed to confirm the sonographic diagnosis. Measurements of the DICA-CV at regular intervals were performed to monitor the progression of retropharyngeal abscess. RESULTS: Retropharyngeal abscess was highly suspected in all cases under sonographic studies. A patient was found to have carotid sheath invasion. Computed tomography confirmed the diagnosis of retropharyngeal abscess in all cases. Retropharyngeal abscess can be evaluated by the measured DICA-CV. The DICA-CV decreased as the retropharyngeal abscess gradually resolved. CONCLUSION: Colour Doppler ultrasonography offers a sensitive method to evaluate retropharyngeal abscess in children. It can also be used to monitor the progression of retropharyngeal abscess and avoid unnecessary radiologic examinations.