Hello, Group
I have two set of images acquired with different imaging protocols (e.g., TRs and bandwidth are different). Can I poll them together for the analysis?
I saw in the email list that some groups reported problems in generating the average of images with different TR for the group analysis. I do not seem have problem to make average include all the images.
But is the result acceptable if the images acquired with multiple protocols?
Thank you
can you give us the details of the protocols? And are you talking about 2 different acquisitions on the same subject, or two groups of subjects with different acquisitions? If the latter then your groups must be balanced in terms of # of subjects for each acquisition type.
On Thu, 16 Aug 2007, Wang, Xin wrote:
Hello, Group
I have two set of images acquired with different imaging protocols (e.g., TRs and bandwidth are different). Can I poll them together for the analysis?
I saw in the email list that some groups reported problems in generating the average of images with different TR for the group analysis. I do not seem have problem to make average include all the images.
But is the result acceptable if the images acquired with multiple protocols?
Thank you
Hello, Dr. Fischl Thank you very much for your quickly response.
flip angle
TI TR TE # Images Band width
9 700 7.796 2.984 164 244.141 9 700 7.48 2.984 164 244.141
9 650 7.48 2.984 164 244.141
Three protocols are different in TR and TI. We are not interested in comparing the protocols. GE just updated patchs for the scanner we are using. We can not run the original protocol (the second one). The first line is what the scanner uses now when we load the original protocol. This update intereupts our data aqusition. we have subjects in two study groups has been scanned with the original protocol, but we may have to use the new protocol from now on for any new subjects in both groups.
We may not be able to balance the number of subjects for each acqusition type between two groups, unless we throw away some data.
Can we use the new protocol to continue our study?
Thank you again,
Xin Wang
________________________________
From: Bruce Fischl [mailto:fischl@nmr.mgh.harvard.edu] Sent: Thu 8/16/2007 11:32 AM To: Wang, Xin Cc: freesurfer Subject: Re: [Freesurfer] images use different protocols
can you give us the details of the protocols? And are you talking about 2 different acquisitions on the same subject, or two groups of subjects with different acquisitions? If the latter then your groups must be balanced in terms of # of subjects for each acquisition type.
On Thu, 16 Aug 2007, Wang, Xin wrote:
Hello, Group
I have two set of images acquired with different imaging protocols (e.g., TRs and bandwidth are different). Can I poll them together for the analysis?
I saw in the email list that some groups reported problems in generating the average of images with different TR for the group analysis. I do not seem have problem to make average include all the images.
But is the result acceptable if the images acquired with multiple protocols?
Thank you
can you do a test-retest on some of the subjects that had the initial protocol to verify that there is no bias?
On Thu, 16 Aug 2007, Wang, Xin wrote:
Hello, Dr. Fischl Thank you very much for your quickly response.
flip angle
TI TR TE # Images Band width
9 700 7.796 2.984 164 244.141 9 700 7.48 2.984 164 244.141
9 650 7.48 2.984 164 244.141
Three protocols are different in TR and TI. We are not interested in comparing the protocols. GE just updated patchs for the scanner we are using. We can not run the original protocol (the second one). The first line is what the scanner uses now when we load the original protocol. This update intereupts our data aqusition. we have subjects in two study groups has been scanned with the original protocol, but we may have to use the new protocol from now on for any new subjects in both groups.
We may not be able to balance the number of subjects for each acqusition type between two groups, unless we throw away some data.
Can we use the new protocol to continue our study?
Thank you again,
Xin Wang
From: Bruce Fischl [mailto:fischl@nmr.mgh.harvard.edu] Sent: Thu 8/16/2007 11:32 AM To: Wang, Xin Cc: freesurfer Subject: Re: [Freesurfer] images use different protocols
can you give us the details of the protocols? And are you talking about 2 different acquisitions on the same subject, or two groups of subjects with different acquisitions? If the latter then your groups must be balanced in terms of # of subjects for each acquisition type.
On Thu, 16 Aug 2007, Wang, Xin wrote:
Hello, Group
I have two set of images acquired with different imaging protocols (e.g., TRs and bandwidth are different). Can I poll them together for the analysis?
I saw in the email list that some groups reported problems in generating the average of images with different TR for the group analysis. I do not seem have problem to make average include all the images.
But is the result acceptable if the images acquired with multiple protocols?
Thank you
freesurfer@nmr.mgh.harvard.edu
-
Bruce Fischl -
Wang, Xin