The B1 Field & Variability in Left-Right Brain Perfusion with 3D IR-PULSAR & Its Implications on Symmetry Studies

Neville D. Gai¹, John Butman¹

Brain perfusion asymmetry is thought to be associated with several cerebrovascular diseases. To a radiologist left-right asymmetry serves a critically important function as a visual cue to the presence of pathology. The ability to assess inter-hemispheric symmetry in the human brain with precision is therefore of importance. Arterial spin labeling is now of routine clinical relevance. Here we study the effect of B1 field inhomogeneity on a whole brain pulsed arterial spin labeling method and show that correcting for transmit and residual B1 inhomogeneity is essential before any inferences can be made based on CBF values particularly related to perfusion asymmetry.