Improved quantification of salivary gland scintigraphy by means of factor analysis

Introduction: In this study the automatic separation of oral and salivary gland activity and spontaneous secretion by means of factor analysis for quantitative salivary gland scintigraphy is introduced. Methods: After intravenous administration of 99mTc sodium pertechnetate, dynamic scintigraphy was performed. 20 minutes after tracer application 2 ml of lemon juice was delivered to stimulate the glands. Applying elliptical regions of interest for oral cavity and four major salivary glands and using factor analysis of medical image sequences (FAMIS) results in factor images and curves, which are used for quantification of the oral, sublingual and glandular activity indexes. Results: With FAMIS it is possible to automatically separate the three superimposed processes seen in salivary gland scintigraphy: glandular and oral activity and spontaneous secretion that results in significant different quantitative results. Conclusion: The application of factor analysis improves the results of salivary gland scintigraphy by separation of superimposed dynamic processes of oral and glandular activity and spontaneous secretion.