Ultra high-resolution fMRI in monkeys with implanted RF coils

Neuron. 2002 Jul 18;35(2):227-42. doi: 10.1016/s0896-6273(02)00775-4.

Abstract

Spatiotemporally resolved functional MRI (fMRI) in animals can reveal how wide-spread neural networks are organized and accompanying electrophysiological recordings can show how small neural assemblies contribute to this organization. Here we present a novel technique that yields high-resolution structural and functional images of the monkey brain with small, tissue-compatible, intraosteally implantable radiofrequency coils. Voxel sizes as small as 0.0113 microl with high signal-to-noise and contrast-to-noise ratios were obtained, revealing both structural and functional cortical architecture in great detail. Up to a certain point, contrast sensitivity increased with decreasing voxel size, probably because of the decreased partial volume effects. Spatial specificity was demonstrated by the lamina-specific activation in experiments comparing responses to moving and flickering stimuli. The implications of this technique for combined fMRI/electrophysiology experiments and its limitations in terms of spatial coverage are discussed.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Brain Mapping / instrumentation
  • Brain Mapping / methods
  • Cerebral Cortex / anatomy & histology*
  • Cerebral Cortex / physiology
  • Cerebrovascular Circulation / physiology
  • Electrodes, Implanted / standards
  • Electrodes, Implanted / trends*
  • Evoked Potentials, Visual / physiology
  • Haplorhini / anatomy & histology
  • Haplorhini / physiology
  • Haplorhini / surgery*
  • Image Processing, Computer-Assisted / instrumentation
  • Image Processing, Computer-Assisted / methods
  • Magnetic Resonance Imaging / instrumentation
  • Magnetic Resonance Imaging / methods*
  • Nerve Net / anatomy & histology
  • Nerve Net / physiology
  • Neurophysiology / instrumentation
  • Neurophysiology / methods*
  • Neurosurgical Procedures / instrumentation
  • Neurosurgical Procedures / methods
  • Photic Stimulation
  • Radio Waves*
  • Skull / anatomy & histology
  • Skull / surgery*
  • Visual Cortex / anatomy & histology
  • Visual Cortex / physiology