Hi Bruce,
My data is loss from 35 to 40. But the uniform of sex is not well from 40 to 55 and from 56 to 71. I did the correlation analysis between age and volume. I don't know how I can explain this problem. Thanks again.
Sincerely, Zheng
At 2017-11-20 09:35:45, "Bruce Fischl" fischl@nmr.mgh.harvard.edu wrote:
Hi Zheng
how uniform is your distribution? I'm hardly an expert on this, but I wouldn't expect very large effects until you get into the older end of that range. Have you scatter plotted your data? Bruce On Mon, 20 Nov 2017, 郑凤莲 wrote:
Hi Bruce,
Thank you for your help. I have 54 subjects, aged from 21 to 71 and only one group. I want to compare the change ofhippocampus volume with age. The results before and after doing the correction for eTIV are the same. Where is wrong? Or if there is no error, how can I explain it in discussion?
Thanks, Zheng
At 2017-11-20 04:55:49, "Bruce Fischl" fischl@nmr.mgh.harvard.edu wrote:
Hi Zheng
yes, I see. Maybe the effect is smaller than you have the power to see, or there is no effect? You would need to give us more details for us to help. Are you correcting for eTIV? What measure are you comparing?
cheers Bruce On Sun, 19 Nov 2017, 郑凤莲 wrote:
Hi Bruce,
I am sorry for this situation. In the first way, there was an statistical difference in left hippocampus, but no differencein
right hippocampus. In the second way, there was both no statistical difference in left or right hippocampus. I don't know what causes this result. Can you understand me this time?
Thanks, Zheng
At 2017-11-18 22:58:56, "Bruce Fischl" fischl@nmr.mgh.harvard.edu wrote:
Hi Zheng
no difference between what and what?
cheers Bruce On Fri, 17 Nov 2017, 郑凤莲 wrote:
Hi professor,
I am using Freesurfer for DTI data. When I run 'mri_segstats', Igot the result that there w
as
an obvious difference in left hippocampus, but no difference in right hippocampus. Then, I run segmentation of hippocampus subfields. The result showed there is no difference in total left
or
right hippocampus, and only in two right hippocampus subfields has significant difference. Why
is
there inconsistent result in two means? Thank you very much.
Sincerely, Zheng