Tobias M.
  Lindig1,2, Sorin Breit1, Ludger Schls1,
  Thomas Ngele, Uwe Klose2, Gunther Helms3
1Department of Neurology and
  Hertie-Institute for Clinical Brain Research, University Hospital Tuebingen,
  Tuebingen, Germany; 2Section of experimental MR of the CNS,
  Department of Diagnostic and Interventional Neuroradiology, University
  Hospital Tuebingen, Tuebingen, Germany; 3MR-Research in Neurology
  and Psychiatry, University Medical Center Goettingen, Goettingen, Germany
The
  pedunculopontine nucleus (PPN) is a potential target for deep brain
  stimulation to address symptoms of gait freezing and postural instability in
  Parkinsons disease. Proton density-weighted (PD-w) MRI has been recommended
  to locate its position. Contrast and delineation of the PPN area in healthy
  subjects were improved by multi-echo 3D MRI at an increased resolution of 0.8
  mm^3, and by using signal amplitude maps S0. These were calculated from a
  dual-angle FLASH protocol, thus eliminating the residual influence of T1 from
  the PD-w images. Usefulness for stereotactic planning was verified on two
  patients at 3T using a protocol of 4x4minutes.
Keywords