james d. christensen, ph.d. iu school of medicine
DESCRIPTION
BME 595 - Medical Imaging Applications Part 2: INTRODUCTION TO MRI Lecture 3 Multi-Dimensional Imaging Feb. 28, 2005. James D. Christensen, Ph.D. IU School of Medicine Department of Radiology Research II building, E002C [email protected] 317-274-3815. References. - PowerPoint PPT PresentationTRANSCRIPT
BME 595 - Medical Imaging ApplicationsPart 2: INTRODUCTION TO MRI
Lecture 3 Multi-Dimensional Imaging
Feb. 28, 2005
James D. Christensen, Ph.D.IU School of Medicine
Department of RadiologyResearch II building, E002C
ReferencesOnline resources for introductory review of MRI physics:
Robert Cox’s book chapters online http://afni.nimh.nih.gov/afni/edu/See “Background Information on MRI” section
Mark Cohen’s intro Basic MR Physics slideshttp://porkpie.loni.ucla.edu/BMD_HTML/SharedCode/MiscShared.html
Douglas Noll’s Primer on MRI and Functional MRIhttp://www.bme.umich.edu/~dnoll/primer2.pdf
Joseph Hornak’s Web Tutorial, The Basics of MRIhttp://www.cis.rit.edu/htbooks/mri/mri-main.htm
Book covering Multi-Dimensional MRI:E. Mark Haacke, et al. Magnetic Resonance Imaging: Physical Principles and Sequence
Design, 1999.
Phase-Encoding
2D Gradient-Echo Pulse Sequence (a)
2D Gradient-Echo Pulse Sequence (b)
2D Gradient-Echo K-Space
Multi-Slice 2D Pulse Sequence
Multi-Slice 2D Slice Excitation
2D Echo-Planar Imaging (EPI)
Pulse Sequence K-Space Trajectory
3D Gradient-Echo Pulse SequencePhase Spoiling:
(RF or gradients) causes Incoherence in transverse magnetization
Fast-Imaging(Steady-State Incoherent pulse sequence)
The steady-state equilibrium magnetization is
where
The transverse magnetization following the nth RF pulse is
For a train of RF pulses repeated every TR seconds
The Steady-State Incoherent signal intensity is proportional to M
Flip Angle (θ), TR & T1 in Fast Imaging
where
Steady-State Incoherent (SSI) signal intensity:
Flip Angle (θ), TR & T1 in Fast Imaging
where
Steady-State Coherence Pulse Sequence
Steady-State Coherence Pulse Sequence
Chemical-Shift Imaging (CSI)
Chemical-Shift Imaging (CSI)
Chemical-Shift Imaging (CSI)
Chemical-Shift Imaging (CSI)
Homework
Problem 1