Table of Contents
Advertisement
fMRI User Guide
8
3.2.7 Accessing Motion Detection Parameters
From the above explanation, it is obvious that there is only one set of motion parameters. The difference lies in
whether they are used for prospective or retrospective motion correction. The motion parameters can be found
under:
VB15: C:\Medcom\MCIR\Med\SimMeasData\MotionDetectionParameter.txt
VB13: C:\MRIR\Med\SimMeasData\MotionDetectionParameter.txt
VB12 and older baselines: C:\MedCom\Temp\MotionDetectionParameter.txt
3.2.8 Dummy scans
FS
G
slice
G
phase
3-line
G
read
Figure 3. Schematic showing how the dummy cycles are performed in the EPI pulse sequence. Assumptions:
TR = 2.5 s, iPAT= 2. Also, for simplicity, the number of slices is assumed to be 1. For a multislice protocol, the
sequence of events will be identical, except that there will be multiple RF pulses and EPI readouts per TR
(equal to the number of slices).
2 dummy scans (2 TRs)
no ADCs
RF
TR
iPAT reference scan,
readout counted
at main TE if using <
max # reference lines
TR
TR
main scan
EPI
Advertisement
Table of Contents
