Scintigraphy for the detection and quantification of subglottic aspiration: preliminary observations

Eleven patients with previously documented aspiration underwent a radioisotopic swallowing study to detect and quantify airway penetration. In those subjects able to complete a rapid-acquisition phase during swallowing, no laryngotracheal penetration was seen despite previous evidence of aspiration. However, sequential static pulmonary imaging showed significant aspiration in three individuals. Attempts were made to measure the percentage of ingested material aspirated and the clearance rate from the airways. Eight patients (73%) failed to show definite evidence of aspiration on scintigrams. It is hypothesized that the lack of scintigraphic detection in previously proven aspirators was due either to interval improvement of the dysphagia or to difficult-to-detect laryngotracheal aspiration. Isotopic imaging during swallowing appears to have little utility; however, after ingestion, the technique can demonstrate more distal penetration not detected on videofluoroscopy. More studies are suggested to better define the sensitivity and specificity of scintigraphy in aspiration detection and to determine whether these techniques have prognostic value that could alter patient management.