vbm 分析_核磁共振分析软件SPM_VBM(灰质计算)_使用手册

VBM Tutorial

John Ashburner

March15,2010

1Getting Started

The data provided are a selection of T1-weighted scans from the freely available IXI dataset1. Note that the scans were acquired in the saggital orientation,but a matrix in the NIfTI headers encodes this information so SPM can treat them as axial.

The overall plan will be to

?Start up SPM.

?Check that the images are in a suitable format(Check Reg and Display buttons).

?Segment the images,to identify grey and white matter(using the SPM→Tools→New Seg-ment option).Grey matter will eventually be warped to MNI space.This step also generates “imported”images,which will be used in the next step.

?Estimate the deformations that best align the images together by iteratively registering the imported images with their average(SPM→Tools→DARTEL Tools→Run DARTEL(create Templates)).

?Generate spatially normalised and smoothed Jacobian scaled grey matter images,using the deformations estimated in the previous step(SPM→Tools→DARTEL Tools→Normalise to MNI Space).

?Do some statistics on the smoothed images(Basic models,Estimate and Results options).

The tutorial will use SPM8,which is is available from http://www.doczj.com/doc/b6cceb2958eef8c75fbfc77da26925c52cc591b4.html/spm/. This is the most recent version of the SPM software2.Normally,the software would be downloaded and unpacked3,and the patches/?xes then downloaded and unpacked so that they overwrite the original release.SPM8should be installed,so there is no need to download it now.

SPM runs in the MATLAB package,which is worth learning how to program a little if you ever plan to do any imaging research.Start MATLAB,and type“editpath”.This will give you a window that allows you to tell MATLAB where to?nd the SPM8software.More advanced users could use the“path”command to do this.

You may then wish to change to the directory where the example data are stored.

SPM is started by typing“spm”or(eg)“spm pet”.This will pop open a bunch of windows. The top-left one is the one with the buttons,but there are also a few options available via the TASKS pull-down at the top of the A4-sized(Graphics)window on the right.

A manual is available in“man\manual.pdf”.Earlier chapters tell you what the various options within mean,but there are a few chapters describing example analyses later on.

SPM requires you to have the image data in a suitable format.Most scanners produce images in DICOM format.The DICOM button of SPM can be used to convert many versions of DICOM into NIfTI format,which SPM(and a number of other packages,eg FSL,MRIcron etc)can use. There are two main forms of NIfTI:

1Now available via http://www.doczj.com/doc/b6cceb2958eef8c75fbfc77da26925c52cc591b4.html/.

2Older versions are SPM2,SPM99,SPM96and SPM91(SPMclassic).Anything before SPM5is considered ancient,and any good manuscript reviewer will look down their noses at studies done using ancient software versions.

3The distribution can be unpacked using WinZip-but ensure that TAR?le smart CR/LF conversion is disabled (under the Miscellaneous Con?guration Options).

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