Detecting pharyngeal post-swallow residue by ultrasound examination: A case series

Yuka Miura, Gojiro Nakagami, Koichi Yabunaka, Haruka Tohara, Koji Hara, Hiroshi Noguchi, Taketoshi Mori, Hiromi Sanada

Research output: Contribution to journalArticlepeer-review

14 Citations (Scopus)


Aims: Prevention of aspiration pneumonia is a great concern in the era of global aging. The assessment of pharyngeal post-swallow residue is important because remaining food and liquid in the pharyngeal area has a possibility of flowing into the lower airway which can cause aspiration pneumonia. Ultrasound examination has been recently used to assess swallowing disorders because of its noninvasiveness. The aim of this study was to investigate the performance for detecting pharyngeal post-swallow residue using an ultrasound examination by comparing with those using a fiberoptic endoscopic evaluation of a swallowing study as a reference. Material and methods: A linear array transducer attached to the thyroid cartilage to visualize the vocal folds in the sagittal plane. The pharyngeal post-swallow residue in the ultrasound movie was interpreted as a misty hyperechoic area above the vocal folds that remained after swallowing. Nineteen ultrasound images simultaneously obtained with fiberoptic endoscopic evaluation of swallowing study images from nine participants (eight men) with a median age of 70 years at a dysphagia outpatient clinic were analyzed by the montage of swallowing examinations. Results: Misty hyperechoic areas above the vocal folds that remained after swallowing were detected in 10 ultrasound images. Eight ultrasound images out of ten correctly detected pharyngeal post-swallow residue. The sensitivity for detecting pharyngeal post-swallow residue of 19 images from nine participants by ultrasound examination was 62%, and the specificity was 67%. Conclusions: The proposed detection method of pharyngeal post-swallow residue by ultrasound examination enabled the real-time assessment for swallowing of people with dysphagia. Ultrasound assessment-based daily swallowing care which detects pharyngeal residue will be useful for preventing aspiration pneumonia.

Original languageEnglish
Pages (from-to)288-293
Number of pages6
JournalMedical Ultrasonography
Issue number3
Publication statusPublished - 2016
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Radiological and Ultrasound Technology
  • Radiology Nuclear Medicine and imaging
  • Acoustics and Ultrasonics


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