Abstract
PURPOSE: This study aimed to assess reliable options for bedside diagnosis of silent aspiration in the intensive care unit by examining the use of default grayscale images (DGI) obtained using a mobile, general-purpose, radiography system capable of dynamic digital radiography (M-DDR) and inverted grayscale images (IGI) of DGI. METHODS: This cohort study (exploratory and preliminary) involved 18 adult patients (mean age, 89.0 years) for whom a swallowing assessment request was received from their primary physicians. Fifty-six IGI videoclips were evaluated by three specialists using the penetration-aspiration scale (PAS), with the gold standard being the consensus reading of all three specialists. Another three speech-language pathologists (SLPs) assessed 56 DGI and IGI videoclips using the PAS. PAS scores 1 and 2 were classified as normal range, PAS scores 3-5 as pathological laryngeal penetration, and PAS scores 6-8 as aspiration. The correct rates with IGI and DGI were then determined, and the level of agreement of IGI and DGI evaluations was evaluated. RESULTS: The correct rate of all evaluators was 100% for normal range, 80-100% for pathological laryngeal penetration, and 83-100% for aspiration with IGI and 100% for normal range, 90% for pathological laryngeal penetration, and 83% for aspiration with DGI. The kappa coefficient for IGI and DGI showed almost complete agreement for abnormal conditions. CONCLUSION: Dynamic imaging of swallowing 2-5 ml of liquid using M-DDR performed for elderly patients at the bedside showed that aspiration assessments by SLPs obtained from DGI videos immediately after imaging are acceptable.