According to information from the National Institute of Standards and Technology (NIST), a team comprised of scientists from its Physical Measurement Laboratory, Radioactivity, and Magnetics groups has created a PET-MR phantom for use in the calibration of PET-MR scanners’ clinical performance, allowing for the development of a national standard for calibrating these machines. The NIST team developed a prototype of the traceable phantom, or calibration standard, for a dedicated PET-MR imager.

NIST reports that the original PET-MR phantom consisted of a plastic sphere roughly the size of a basketball, filled with salt solutions that become magnetized in a magnetic field. The new phantom prototype includes a small, calibrated amount of fluorine-18 (F-18), a radionuclide that shows up in PET images. The prototype is said to have accuracy within 1.5%, which is sufficient for most applications, though the team reportedly hopes to increase this accuracy to less than 1%.

The NIST team expects to build and test the next version of the prototype within a year, and reports that it will feature a more robust and user-friendly design, including sturdier walls and an improved filling system that makes it easier and faster to introduce the radioactive solutions. The future model may also include calibrated samples of solid, longer-lived radioactive sources for tests that can further monitor PET scanner performance, according to NIST.

For more information about the PET-MR phantom prototype, see the NIST press release.