Use of Static Imaging as a Substitute for Conventional Dynamic Imaging for Salivagrams in Children

Salivagrams are commonly used for detecting pulmonary aspiration. However, conventional dynamic imaging is relatively time-consuming and could be difficult to perform in children with poor compliance. We analyzed the characteristics of conventional dynamic imaging to obtain a simple protocol suitable for use in children.

We conducted a retrospective analysis of salivagram data from 1163 patients (783 males, 380 females; age, 1 month to 9.0 years; mean age, 5.7 months) obtained in the past 4.5 years (January 2014 to June 2018). The various timepoint images were used for diagnosis. The positivity rate, missed diagnosis rate, and sensitivity were calculated and compared.

Dynamic imaging revealed 353 cases of pulmonary aspiration (248 males, 105 females; age, 1 month to 4.5 years; mean age, 6.2 months). The positivity rate was 30.4% (353/1163), and 95.8% (338/353) of patients presented with continuous positive images after pulmonary aspiration. Only 4.2% (15/353) of positive cases showed clearance of pulmonary aspiration. The positivity rates were 11.8%, 18.2%, 21.9%, 25.0%, 27.0%, and 29.2% at 5, 10, 15, 20, 25, and 30 minutes, respectively. About 4.2% (15/353) of positive cases on earlier images showed clearance of pulmonary aspiration on later images, which indicate both early 15-minute and later 30-minute images were necessary.

Two static images acquired at 15 and 30 minutes might be an effective alternative to conventional salivagram, which mandates dynamic imaging.