A method and apparatus for quantifying pharyngeal residue and aspiration of a patient by x-ray imaging of the patient's head and neck to produce a baseline image, applying an initial volume of x-ray opaque solution to a patient by mouth; x-ray imaging the head and neck of the patient having received the solution before and after swallowing to produce respective second and third images; and calculating a ratio of the pharyngeal residue volume to the initial volume to determine the proportion of the swallowed bolus that remain in the pharyngeal recesses; and calculating a ratio of the material entering the trachea to the known initial volume to determine the proportion of the swallowed bolus that has been aspirated; and if the volume of the original bolus is known, calculating the actual volume of the pharyngeal residue and aspiration. The apparatus includes a suitably programmed computer and an x-ray imaging system to collect image data.