Incidental mastoid opacification on computed tomography in the pediatric population.

OBJECTIVES

Incidental mastoid opacification (IMO) is a common radiologic finding and source of referral to otolaryngologists. Our objectives were to: 1) determine the rate of IMO in our pediatric population; 2) identify those with clinical mastoiditis; and 3) identify factors necessitating an otolaryngology consultation.

METHODS

This was a retrospective chart review at an academic, tertiary, pediatric hospital in an urban setting. Pediatric patients with the keyword 'mastoid' on a computed tomography (CT) scan report were reviewed. The effect of age, gender, season and the use of contrast media on the rate of IMO was also analyzed. Chi-square analysis was used to compare the significance of categorical frequencies.

RESULTS

The rate of IMO in our cohort was 14.2% (164/1157). In children <8 years of age, the IMO rate was 22.0% compared to 5.6% in children 8-17 years of age (p < .001). The IMO rate in male children was 16.6% compared to 11.0% in female children (p = .007). There was no statistically significant higher rate of IMO during winter (15.1%) compared to summer (9.0%) and in CT scans with contrast (16.0%) compared to without contrast (14.0%). Our department of otolaryngology was formally consulted in 3% (5/164) of IMO cases. None of those patients had clinical mastoiditis.

CONCLUSIONS

This is the largest study identifying IMO on CT and in children to date. Although the overall rate of IMO in the pediatric population is 14.2%, it is rarely clinically significant.