Multi-printed inkjet phantoms for radionuclide molecular imaging

This work describes the multi-printing technique for preparing, with a commercial inkjet printer and radio marked ink, planar emission phantoms particularly suitable for high-resolution radionuclide imaging. The well known practice of producing radioactive phantoms by inkjet was improved by developing the multi-printing technique definable as the reiteration of printing commands before processing the next line. The major advantage consists of the increase of the concentration of radioactivity deposited in the image with respect to the standard over-printing method without refilling radioactivity in the cartridge. Since the paper needs just one insertion in the printer, a better outlined image is produced than in the case of the over-printing technique obtainable by reiterating both the insertion and the printing of the same image over of the same sheet. This paper discusses in particular: (1) the linear dependence of deposited activity vs. the number of multi-printing cycles; (2) the effective decay’s time of radio marker at nozzle’s output; (3) the evaluation of the absolute value of the activity deposited in the image and (4) the broadening of the printed surfaces vs. the number of multi-printing cycles.