Dr. Stephen E. Russek (NIST): Making Magnetic Resonance Imaging into a Precise Metrology
Magnetic Resonance Imaging (MRI) is a powerful biomedical imaging technique that is still widely used in a qualitative manner, in which images are interpreted by radiologists based only on relative contrast. MRI, however, can be used quantitatively to measure in-vivo many important local parameters such as tumor volumes, proton spin relaxation times, temperature, water diffusion, fat fraction, and tissue elasticity. For these measurements to be used clinically, these parameters must be well defined, consistently and precisely measured across different scanners and time, be diagnostic of tissue health and pathology, and be safe and cost-effective. Here, I will present NIST efforts to develop standards to help validate MRI-based in-vivo measurements and discuss challenges of making in-vivo measurements with well-defined uncertainties. I will give an overview of NIST programs, such as the MRI Biomarker Calibration Service, the NIST/NIBIB Medical Phantom Lending Library, and medical metrology research (see Magnetic Imaging Group) which are designed to help MRI transition into a quantitative in-vivo metrology tool.