Three-dimensional brain MRI for DBS patients within ultra-low radiofrequency power limits

Mov Disord. 2014 Apr;29(4):546-9. doi: 10.1002/mds.25808. Epub 2014 Jan 17.


Background: For patients with deep brain stimulators (DBS), local absorbed radiofrequency (RF) power is unknown and is much higher than what the system estimates. We developed a comprehensive, high-quality brain magnetic resonance imaging (MRI) protocol for DBS patients utilizing three-dimensional (3D) magnetic resonance sequences at very low RF power.

Methods: Six patients with DBS were imaged (10 sessions) using a transmit/receive head coil at 1.5 Tesla with modified 3D sequences within ultra-low specific absorption rate (SAR) limits (0.1 W/kg) using T2 , fast fluid-attenuated inversion recovery (FLAIR) and T1 -weighted image contrast. Tissue signal and tissue contrast from the low-SAR images were subjectively and objectively compared with routine clinical images of six age-matched controls.

Results: Low-SAR images of DBS patients demonstrated tissue contrast comparable to high-SAR images and were of diagnostic quality except for slightly reduced signal.

Conclusions: Although preliminary, we demonstrated diagnostic quality brain MRI with optimized, volumetric sequences in DBS patients within very conservative RF safety guidelines offering a greater safety margin.

Keywords: Parkinson's disease; conditional magnetic resonance imaging; deep brain stimulation; low specific absorption rate; radiofrequency heating.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Brain / pathology*
  • Deep Brain Stimulation*
  • Electrodes, Implanted*
  • Essential Tremor / pathology
  • Essential Tremor / therapy
  • Female
  • Humans
  • Magnetic Resonance Imaging / methods*
  • Male
  • Middle Aged
  • Parkinson Disease / pathology
  • Parkinson Disease / therapy