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 of hippocampus 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 difference in
>> 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', I 
>> >> got 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
>> >> 
>> >> 
>> >> 
>> >>  
>> >> 
>> >> 
>> >>
>> 
>> 
>> 
>>  
>> 
>> 
>>