Algorithm for Lipid Suppression by Real-Time Isotropic Filter Design in Spectroscopic Brain Imaging

Joonsung Lee¹, Elfar Adalsteinsson^1,2

Estimates of brain metabolites using MRSI are severely hampered by strong lipid signals even though the interfering signal arises from regions outside of the brain. Variable-density sampling of k-space with accompanying proportional filtering reduces the spatial side-lobes within the brain due to the extra-brain lipid sources. We present an improved algorithm that achieves a direct design of a subject-specific, optimal, spherically symmetric spatial filter in two or three dimensions to minimize lipid contamination estimated by pre-scans. The proposed method is demonstrated with single-slice MRSI to achieve 30~40 dB or lipid suppression in the absence of OVS or inversion recovery pulses.