fMRIの原理

Functional MRI (fMRI)
For internal use only / Copyright © Siemens AG 2006. All rights reserved.
fMRI
MRI
Page 2
APG / CS / SJKK_120034
fMRI
PET
MEG
NIRS
EEG
fMRI
Page 3
fMRI
APG / CS / SJKK_120034
BOLD Blood Oxygen on Level Depending
5%
30 50%
Page 4
APG / CS / SJKK_120034
BOLD Blood Oxygen on Level Depending
fMRI
EPI
Echo Planner Imaging
3%
???
Page 5
Baseline
Active
APG / CS / SJKK_120034
Blocked design
t
Event related design
BOLD
20s
20s
t
Page 6
APG / CS / SJKK_120034
PC
MRI
MRI
PC
MRI
PC
Page 7
APG / CS / SJKK_120034
t
Finger tapping = ON
887.52
830.76
Finger tapping = OFF
Page 8
APG / CS / SJKK_120034
GLM general linear model
fMRI
Y=X
BOLD signal
HRF model Hemodynamic Response Function)
Page 9
Design Matrix
APG / CS / SJKK_120034
BOLD
fMRI
GLM statistic
SPM
Page 10
APG / CS / SJKK_120034
Mesurement, Paradigm size
BOLD
TR
Slice 1 2 3 4 5 …
Baseline
Active
t
Paradigm size = 20
Measurement = 60
Page 11
APG / CS / SJKK_120034
t
fMRI
3D PACE
Motion Correction
S Thensen, : Prospective Acquisition Correction for Head Motion
with Image-based Tracking for Real-Time fMRI. ISMRM(2000)
Page 12
APG / CS / SJKK_120034
3D PACE
measurement
measurement
Prospective
Sequence name ep2d_pace 3D PACE
Measurement (n)
ep2d_bold
Measurement delay
FFT
Measurement (n+1)
Position
Update
Motion
Detection
Regridding of residual motion
0,0 s
Page 13
1,8 s
4,0 s
APG / CS / SJKK_120034
Motion Correction
BOLD
Retrospective
BOLD
Page 14
APG / CS / SJKK_120034
Spatial Filter
BOLD
SNR
2
1
0.5
Page 15
Weak
Average
Strong
APG / CS / SJKK_120034
Delay in TR
Delay in TR
BOLD
TR
Delay in TR
Delay in TR > 0
Delay in TR = 0
Slice 1 2 3 4 5
TR
Page 16
= 1 measurement
APG / CS / SJKK_120034
Series
Geometry >> Common
Series
Interleaved
Ascending
Descending
Interleaved
(
10
4
3
2
1
1
2
3
4
10
Interleaved
)
(
)
5
9
4
8
3
7
2
6
1
5
10
4
9
3
8
2
7
1
6
interleave
interleave
Page 17
APG / CS / SJKK_120034
TR
Page 18
APG / CS / SJKK_120034
Mosaic Image
fMRI
1 mosaic (all slice) / 1mesurement
Page 19
APG / CS / SJKK_120034

Download Report