Karin Shmueli1, Ruth O'Gorman2,3,
David Lythgoe4, Michael Samuel5, Richard Selway6,
Keyoumars Ashkan6, Jozef Jarosz2
1Advanced MRI Section, Laboratory of
Functional and Molecular Imaging, National Institute of Neurological
Disorders and Stroke, National Institutes of Health, Bethesda, MD, United
States; 2Department of Neuroradiology, King's College Hospital,
London, United Kingdom; 3MR-Zentrum, University Childrens Hospital,
Zurich, Switzerland; 4Centre for Neuroimaging Sciences, Institute
of Psychiatry, King's College London, United Kingdom; 5Department
of Neurology, King's College Hospital, London, United Kingdom; 6Department
of Neurosurgery, King's College Hospital, London, United Kingdom
Susceptibility-Weighted
Imaging (SWI) improves the visibility of target structures (globus pallidus
(GP) and subthalamic nucleus (STN)) for deep brain stimulation (DBS).
However, because phase contrast is non-local and orientation dependent, SWI
contains artifacts that may result in targeting errors. Susceptibility maps,
which have shown promise for overcoming such artifacts, were calculated from
clinical 1.5-T phase data acquired at a single orientation. 2-mm shifts in
the superior borders of the red nuclei and GP in the SWI relative to the
susceptibility maps were observed in several volunteers and DBS patients
showing that susceptibility mapping may help reduce SWI targeting errors.