Functional imaging by I0- and T2*-parameter mapping using multi-image EPI

Magn Reson Med. 1998 Aug;40(2):243-8. doi: 10.1002/mrm.1910400210.

Abstract

A new functional imaging method has been developed and used to measure T2*- and initial intensity (I0)-parameter maps of multiple slices during activation of the cortex with high temporal resolution. Multiple echo-planar images (EPIs) are read out after a single excitation of the spin system, leading to several images with increasing effective echo times. Changes induced by primary visual stimulation in T2* and I0 were measured in eight subjects. Although stimulation-induced increases in I0 only occurred at short repetition times, T2* increased from 57.3 to 60.9 ms on average. The method combines the high stability of a single shot EPI experiment with the high information content of a multiecho acquisition. In addition, stimulation-induced changes in inflow can be easily separated from true blood oxygenation level dependent (BOLD) signal changes.

MeSH terms

  • Arousal / physiology*
  • Brain Mapping
  • Cerebral Cortex / physiology*
  • Echo-Planar Imaging / instrumentation*
  • Equipment Design
  • Humans
  • Image Processing, Computer-Assisted*
  • Magnetic Resonance Imaging / instrumentation*
  • Oxygen Consumption / physiology
  • Pattern Recognition, Visual / physiology
  • Sensitivity and Specificity
  • Visual Cortex / physiology