Scintigraphic evaluation of sialadenitis

Salivary gland scintigraphy using 99Tcm sodium pertechnetate and a 20-min dynamic data acquisition with a sialogogue at 10 min was employed as the primary imaging modality in sialadenitis in 32 patients. Paired asymptomatic glands within the study group were used to establish control values for a number of computer-derived functional parameters. The shape of the activity-time curve was described as: H = hyperactive, N = normal, M = median, S = sloped, F = flat, O = obstructed. Of seven patients who had ductal stones on plain films, two passed stones prior to sialography and had normal curves, whole the remaining five patients had Type O curves. Parametric evidence of gland dysfunction was identified in an additional seven symptomatic glands, six being hyperactive; histology identified an acute inflammatory infiltrate in the only excised gland in this group. Glandular hypofunction was identified in one case, in which histology revealed extensive fibrosis and glandular atrophy. Type M and S curves were found in 28 glands, 75% of which were asymptomatic. Only one gland was indicated as hypoactive by calculated parameters, and this showed a Type S curve. Scintigraphy and plain films represent the least invasive and, we feel, the most suitable primary method of investigating sialadenitis. Conventional contrast sialography may be reserved for cases with no identifiable stone but an obstructed curve. The use of functional parameters and curve morphology to determine gland dysfunction other than obstruction is non-specific, probably insensitive and is unlikely to alter clinical management. We propose an algorithm for the investigation of sialadenitis.