Basic Physics of fMRI

Table of Contents

Basic Physics of fMRI

MRI System Block Diagram

fMRI Additions

Nuclear Spin

Common Active NMR Nuclei

Alignment of Spins in a Magnetic Field

Energy in a Magnetic Field(Zeeman Splitting, Spin ½)

Larmor Frequency

MRI System

Principle of Gradient Coil

Coupling with a B1 Field

Free Induction Decay

1D Imaging Example

1D Imaging Example

1D Imaging Example

1D Imaging Example

1D Imaging Example

2D Back Projection Imaging

Slice Selection

2D Projection Reconstruction

2D Fourier Imaging Sequence

Principle of k-Space

2D Projection Reconstruction

2D Fourier Imaging

Magnetic Resonance Measurements

MRI Applications

Important Nuclear Relaxation Times

Scan Repeat Time TR

Mz Recovery Following a 90º Pulse

T1 Recovery Curves

T1 Weighted Image

Approach to Steady State

Time to Echo TE

T2 Decay Curve

T2 Decay Curves

T2 Weighted Image

Proton Density Contrast

Summary of Proton Density, T1 and T2 weighting

Summary of Proton Density, T1 and T2 weighting

T2 Versus T2*

T2 Versus T2*

Functional MRI

Conventional Gradient Echo Imaging

Echo Planar Imaging

Functional Imaging Sequences

Gradient Echo EPI

Visual Stimulation

Visual Stimulation

Conclusions

Email: peterj@fmrib.ox.ac.uk

Home Page: http://www.fmrib.ox.ac.uk

Other information:
FMRIB Centre, University of Oxford, John Radcliffe Hospital, Headington, Oxford, OX3 9DU, ENGLAND