Fluorescent Excitation in the Measurement of Clearance of Heavy Metals from the Lungs

Measurement of the clearance of insufflated tantalum and barium sulfate powder from the lung is important in evaluating tantalum as a roentgenographic contrast agent, as well as in the investigation of lung clearance mechanisms. This report evaluates the technique of fluorescent excitation for measuring clearance of particulate tantalum and barium sulfate from the lungs, using a 2-Ci gadolinium-153 (153Gd) source and an 80 mm2 lithium-doped silicon (Si(Li)) detector.