A New High Sensitivity Thyroid X-Ray Fluorescence Scanning System

An array of five Si(Li) detectors which partially surrounds a collimated 10 Ci 241Am source, combined with a microprocessor-controlled scanning bed, has been developed for imaging of stable iodine within the thyroid. The sensitivity of the system is sufficient to generate high-quality scan images in a scanning time of approximately 15 minutes, with a spatial resolution of 5.9 mm (FWHM). We have evaluated several phantom studies and used the results to develop a computer code which determines the total thyroid iodine content and thyroid area with acceptable accuracy.