The National Institute of Standards and Technology (NIST) provides the physical measurements and standards in a variety of fields, including for ionizing radiation, for the US. Building on a long history of providing standards for medical x rays and radionuclides used in nuclear medicine, NIST has expanded its focus to better support the extensive use of medical physics in the US today, providing confidence in key results needed for drug and device development and marketing, therapy planning and efficacy, and disease screening. In particular, to support more quantitative medical imaging, NIST has implemented a program to provide key measurement infrastructure to support radiation-based imaging through developing standard, benchmark phantoms, which contain NIST-calibrated radioactive sources, to allow more quantitative imaging through traceable instrument calibration for clinical trials or patient management. Working closely with colleagues at NIH, Rensselaer Polytechnic Institute, the Food and Drug Administration (FDA), and Cornell University, we have taken our initial steps in developing phantoms, and the protocols to use them, for more accurate calibration of PET (or SPECT) cameras, including recently standardizing 68Ge. X-ray measurements of our recently developed small, resilient and inexpensive length standard phantom have shown the potential usefulness of such a pocket phantom for patient-based calibration of CT (alone or with PET) systems. The ability to calibrate diagnostic imaging tools in a way that is traceable to national standards will lead to a more quantitative approach; both physician and patient benefit from increased accuracy in treatment planning, as well as increased safety for the patient.
Citation: Medical Physics
Pub Type: Journals
computed tomography (CT), dosimetry, imaging, phantoms, positron emission tomography (PET), treatment planning