Issel Anne L. Lim1, 2, Xu Li2, 3, Craig K. Jones2, 3, Jonathan A. D. Farrell2, 3, Deepti S. Vikram2, 3, Carlos A. Renjifo4, Peter C. M. van Zijl2, 3
1Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, United States; 2F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, United States; 3Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, United States; 4Johns Hopkins University Applied Physics Laboratory, Laurel, MD, United States
Quantitative susceptibility imaging (QSM) can characterize the local magnetic environment of the brain, which is affected by chemical content of the tissues. Currently, QSM techniques utilize gradient echo imaging (GRE) to measure spatial differences in signal phase, identify local field (frequency) differences, and calculate susceptibility. We compare susceptibility maps generated from GRE to the WAter Saturation Shift Referencing (WASSR) method, which determines the resonance frequency per voxel through measurement of direct water saturation as a function of RF pulse offset frequency. Results from five normal male volunteers at 3T correlate with iron concentration in the brain.