You can estimate resolution somewhat accurately by looking at reconstructed images of certain phantoms/inserts (cold rods, for example). By knowing the rod diameters for given sectors of the rod insert, you look to see if most rods in that sector are visible. You can then say that resolution is approximately whatever the rod sizes are …… but that does not answer your question. To actually measure your resolution you should perform a scan of something like capillary line sources. The DSC QC phantom is designed so that (typically glass) capillary line sources can be mounted in the filler caps of the phantom. You can also devise your own method for mounting sources and do not need a special phantom to perform this measurement, other than the tubes themselves. Please see the Users Manual for how to actually mount them in the QC phantom. Information is available on how to make your own and where to buy glass capillary tubes.Once you have scanned and reconstructed the line sources, you can use your computer’s software to get image profiles. If you are lucky, your computer will have a quick method of determining the full-width at half maximum (FWHM) and full-width at tenth maximum (FWTM) from the profiles. If not, you hopefully can print out the profile values and input them into third party software that can perform these calculations.