Instant Measurement of Point Spread Functions using an NMR Field Probe

Lars Kasper^1,2, Bertram Jakob Wilm¹, Christoph Barmet¹, Klaas Paul Prssmann¹

The point spread function (PSF) is a comprehensive concept to describe the imaging and reconstruction process in MRI. Its analysis gives insight into the signal model of MR sequences as well as their imperfections, thus revealing true resolution and typical artifacts. By definition, the PSF describes the mapping of a point source of MR signal onto pixels of an image reconstruction matrix. We take this definition literally and use a miniaturized water-filled NMR field probe to determine the PSF experimentally. Hereby, we treat the MR scanner as a black box and infer information about the reconstruction characteristics solely from probing.