Exporting ROI volumes/thickness values may not be significant because the analysis in qdec (glm) includes the whole cortical surface.
But, I have a follow up question to this question. In the plotted graph the abscissa reports F values. Which basically mean that the significant ROI reflects the distribution of F values. So for example the older the person the greater the F value in that region for thickness/volume. But that doesn't mean that thickness/volume in that region actually varies with age, rather that relative to the rest of the surface the older the person this ROI is more likely it is to be associated with age. Correct? Thanks Ilana On 4/27/11 8:12 PM, "Gallen, Courtney (NIH/NIDA) [F]" <galle...@nida.nih.gov> wrote: >Hi Doug > >Have a follow up question regarding significance levels in Qdec related >to extracting means from ROIs, etc. I'm posting to the entire mailing >list in case anyone else has ideas. > >Basically, I extracted mean volumes (from my set of participants) of ROIs >for which Qdec reports an interaction between two variables. I want to >look at these mean volumes in something like SPSS to see what is driving >the interaction/generate figures, etc. > >I'm having an issue with one such ROI, in that when I extract the mean >volumes and look for this interaction in SPSS, it is not significant (p ~ >0.5, so really not significant at all). Is there any way that an ROI >could be significant in Qdec (p of 0.05, Monte Carlo sim), but not in >SPSS when I extract means for each participant? > >Let me know if this isn't clear. Any thoughts would be appreciated! >Courtney > > >Courtney Gallen >Post-baccalaureate IRTA >Neuroimaging Research Branch >National Institute on Drug Abuse (IRP) >251 Bayview Blvd >Suite 200 >Baltimore, MD 21224 >Tel: (443) 740-2631 > >-----Original Message----- >From: Douglas Greve [mailto:gr...@nmr.mgh.harvard.edu] >Sent: Tuesday, April 26, 2011 1:06 PM >To: Gallen, Courtney (NIH/NIDA) [F] >Subject: Re: [Freesurfer] Interpreting results from Qdec > >Those are the values outside (first column) and inside (2nd col) the >ROI. You can add "--id 1" to only report the values inside the ROI. > >doug > >On 4/26/11 1:02 PM, Gallen, Courtney (NIH/NIDA) [F] wrote: >> It worked! >> Now, last question. The txt file has two separate values (?averages). >>What do they each represent? >> >> -----Original Message----- >> From: Douglas Greve [mailto:gr...@nmr.mgh.harvard.edu] >> Sent: Tuesday, April 26, 2011 12:53 PM >> To: Gallen, Courtney (NIH/NIDA) [F] >> Subject: Re: [Freesurfer] Interpreting results from Qdec >> >> try "--slabel fsaverage lh ROI-drawn-on-QDEC-brain.label" >> >> >> On 4/26/11 12:52 PM, Gallen, Courtney (NIH/NIDA) [F] wrote: >>> Actually, I hope I'm wrong about what I thought below. If I specify >>>individual subject's label and run: >>> >>> mri_segstats --in >>>/prot/Mprot/CTQ/freesurferDone/8579/surf/lh.volume.fwhm10.fsaverage.mgh >>>--slabel 8579 lh >>>/prot/Mprot/CTQ/freesurferDone/8579/label/lh.SupTemp_CTQxBDNFctrls.label >>> --avgwf lhSupTempctrls.txt >>> >>> I still get the same error about dimension mismatch >>> >>> >>> -----Original Message----- >>> From: Gallen, Courtney (NIH/NIDA) [F] >>> Sent: Tuesday, April 26, 2011 12:43 PM >>> To: 'Douglas Greve' >>> Subject: RE: [Freesurfer] Interpreting results from Qdec >>> >>> Ah I think I see the problem now. >>> >>> The label I originally specified is the general label created from the >>>ROI drawing in Qdec. Instead, I should use the individual subject's >>>label (from 'Map Label to Subjects') instead, right? >>> >>> Thank you! >>> >>> -----Original Message----- >>> From: Douglas Greve [mailto:gr...@nmr.mgh.harvard.edu] >>> Sent: Tuesday, April 26, 2011 12:38 PM >>> To: Gallen, Courtney (NIH/NIDA) [F] >>> Subject: Re: [Freesurfer] Interpreting results from Qdec >>> >>> You have to use the subject that matches the input, fsaverage in this >>> case. How did you define your label? If you defined it on subject 123, >>> you can transfer it to fsaverage using mri_label2label. >>> doug >>> >>> On 4/26/11 12:28 PM, Gallen, Courtney (NIH/NIDA) [F] wrote: >>>> Not a problem at all! >>>> >>>> If I use --in, I get an error saying that there is a dimension >>>>mismatch between input volume and seg. >>>> >>>> Any other thoughts? Thanks again! >>>> >>>> -----Original Message----- >>>> From: Douglas Greve [mailto:gr...@nmr.mgh.harvard.edu] >>>> Sent: Tuesday, April 26, 2011 11:40 AM >>>> To: Gallen, Courtney (NIH/NIDA) [F] >>>> Subject: Re: [Freesurfer] Interpreting results from Qdec >>>> >>>> >>>> Hi Courtney, sorry for the delay. If more than a few days go by >>>>without >>>> a response, feel free to repost -- I promise not to get annoyed! >>>> Sometimes, things get pushed up and out of my mail browser window, >>>>and I >>>> often don't get back to them. Sorry! >>>> >>>> To answer your question, try using --in where you have --seg. The >>>> "segmentation" is actually already specified because you've specified >>>>a >>>> label. >>>> >>>> doug >>>> >>>> On 4/26/11 11:03 AM, Gallen, Courtney (NIH/NIDA) [F] wrote: >>>>> Hi Doug, >>>>> Sorry to keep bugging you but any thoughts about my response to your >>>>>e-mail from 2 weeks ago? I've given the exact command line I'm using >>>>>with mri_segstats. >>>>> Thanks again for all your help >>>>> Courtney >>>>> >>>>> -----Original Message----- >>>>> From: Gallen, Courtney (NIH/NIDA) [F] >>>>> Sent: Tuesday, April 12, 2011 10:59 AM >>>>> To: 'Douglas N Greve' >>>>> Subject: RE: [Freesurfer] Interpreting results from Qdec >>>>> >>>>> That may be the problem. ${sub} is an actual person's directory >>>>> >>>>> E.g., sub# 123--command line would be: >>>>> mri_segstats --seg >>>>>/prot/Mprot/CTQ/freesurferDone/123/surf/lh.volume.fwhm10.fsaverage.mgh >>>>> --slabel 123 lh \ >>>>> lh.SupTemp_CTQxBDNFctrls.label --avgwf lhSupTempctrls.txt >>>>> >>>>> >>>>> >>>>> -----Original Message----- >>>>> From: Douglas N Greve [mailto:gr...@nmr.mgh.harvard.edu] >>>>> Sent: Tuesday, April 12, 2011 10:55 AM >>>>> To: Gallen, Courtney (NIH/NIDA) [F] >>>>> Subject: Re: [Freesurfer] Interpreting results from Qdec >>>>> >>>>> What is your full command-line? Without variables, just something >>>>>that >>>>> you could put directly into the terminal. Make sure that you are >>>>> specifying fsaverage as your subject (can't tell below because your >>>>>use >>>>> ${sub}). >>>>> >>>>> doug >>>>> >>>>> >>>>> Gallen, Courtney (NIH/NIDA) [F] wrote: >>>>>> Sorry, but I can't seem to figure out how to specify input data. I >>>>>>tried '--in' but get an error that the input vol and seg label are >>>>>>not the same dimensions. I've been looking at the help options for >>>>>>mri_segstats (http://surfer.nmr.mgh.harvard.edu/fswiki/mri_segstats) >>>>>>but don't see it >>>>>> >>>>>> -----Original Message----- >>>>>> From: Douglas N Greve [mailto:gr...@nmr.mgh.harvard.edu] >>>>>> Sent: Friday, April 08, 2011 10:38 AM >>>>>> To: Gallen, Courtney (NIH/NIDA) [F] >>>>>> Subject: Re: [Freesurfer] Interpreting results from Qdec >>>>>> >>>>>> The lh.volume.fwhm10.fsaverage.mgh should be your input. It is not >>>>>>a >>>>>> segmentation. You've already specified the seg with the the --slabel >>>>>> command. >>>>>> doug >>>>>> >>>>>> >>>>>> Gallen, Courtney (NIH/NIDA) [F] wrote: >>>>>> >>>>>>> One last question (hopefully). I'm specifying the input volume >>>>>>>with --seg, but am getting an error ('cannot do frame average >>>>>>>without input volume'). Am I missing something obvious? >>>>>>> >>>>>>> The entire command looks something like this: >>>>>>> mri_segstats --seg >>>>>>>/prot/Mprot/CTQ/freesurferDone/${sub}/surf/lh.volume.fwhm10.fsaverag >>>>>>>e.mgh --slabel ${sub} lh \ >>>>>>> lh.SupTemp_CTQxBDNFctrls.label --avgwf lhSupTempctrls.txt >>>>>>> >>>>>>> Thanks again >>>>>>> -----Original Message----- >>>>>>> From: Douglas N Greve [mailto:gr...@nmr.mgh.harvard.edu] >>>>>>> Sent: Tuesday, April 05, 2011 4:21 PM >>>>>>> To: Gallen, Courtney (NIH/NIDA) [F] >>>>>>> Cc: Nick Schmansky; Freesurfer Mailing List >>>>>>> Subject: Re: [Freesurfer] Interpreting results from Qdec >>>>>>> >>>>>>> yes, something like ?h.volume.fwhm10.fsaverage.mgh >>>>>>> doug >>>>>>> >>>>>>> Gallen, Courtney (NIH/NIDA) [F] wrote: >>>>>>> >>>>>>> >>>>>>>> Hi Doug >>>>>>>> >>>>>>>> Thanks for helping me with this! >>>>>>>> >>>>>>>> First time around I did everything as is outlined in 'Define a >>>>>>>>Region of Interest' here: >>>>>>>>http://surfer.nmr.mgh.harvard.edu/fswiki/FsTutorial/QdecGroupAnalys >>>>>>>>is. >>>>>>>> >>>>>>>> I'll try your suggestion now. The input data would be something >>>>>>>>like ?h.volume.fwhm10.fsaverage.mgh, correct? >>>>>>>> >>>>>>>> Thanks again >>>>>>>> Courtney >>>>>>>> >>>>>>>> -----Original Message----- >>>>>>>> From: Douglas N Greve [mailto:gr...@nmr.mgh.harvard.edu] >>>>>>>> Sent: Thursday, March 31, 2011 5:44 PM >>>>>>>> To: Gallen, Courtney (NIH/NIDA) [F] >>>>>>>> Cc: Nick Schmansky; Freesurfer Mailing List >>>>>>>> Subject: Re: [Freesurfer] Interpreting results from Qdec >>>>>>>> >>>>>>>> Hi Courtney, did you transfer the label to each individual >>>>>>>>subject using >>>>>>>> mri_label2label? A better way to replicate your qdec results is >>>>>>>>to run >>>>>>>> mri_segstats on the input data to qdec (y.mgh usually). Specify >>>>>>>>the >>>>>>>> label with "--slabel subject hemi yourlabel". Also specify >>>>>>>>"--avgwf >>>>>>>> subjectdata.txt". This will create this text file with a list of >>>>>>>>the >>>>>>>> input data for each subject averaged over your label. >>>>>>>> >>>>>>>> doug >>>>>>>> >>>>>>>> Gallen, Courtney (NIH/NIDA) [F] wrote: >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>>> Hi Nick >>>>>>>>> >>>>>>>>> I'm revisiting this issue and have a few more questions. First, >>>>>>>>>I have a significant interaction between two variables on >>>>>>>>>cortical volume. I drew a label on this ROI and ran >>>>>>>>>mris_anatomical_stats on the label (thank you for that >>>>>>>>>suggestion). >>>>>>>>> >>>>>>>>> For stats in the output table file, is the column 'GrayVol' the >>>>>>>>>same thing as the cortical volume I looked at in Qdec? I'm asking >>>>>>>>>because when I export GrayVol values into SPSS, there is no >>>>>>>>>longer a significant interaction between my variables (and if >>>>>>>>>this ROI is significant after multiple comparisons across the >>>>>>>>>brain, I'd expect the mean volume from the ROI to be very >>>>>>>>>significant in SPSS). >>>>>>>>> >>>>>>>>> Please let me know if my questions aren't clear. Thanks in >>>>>>>>>advance >>>>>>>>> Courtney >>>>>>>>> >>>>>>>>> >>>>>>>>> Courtney Gallen >>>>>>>>> Post-baccalaureate IRTA >>>>>>>>> Neuroimaging Research Branch >>>>>>>>> National Institute on Drug Abuse (IRP) >>>>>>>>> 251 Bayview Blvd >>>>>>>>> Suite 200 >>>>>>>>> Baltimore, MD 21224 >>>>>>>>> Tel: (443) 740-2631 >>>>>>>>> >>>>>>>>> >>>>>>>>> -----Original Message----- >>>>>>>>> From: Nick Schmansky [mailto:ni...@nmr.mgh.harvard.edu] >>>>>>>>> Sent: Thursday, January 13, 2011 3:08 PM >>>>>>>>> To: Gallen, Courtney (NIH/NIDA) [F] >>>>>>>>> Cc: Freesurfer Mailing List >>>>>>>>> Subject: Re: [Freesurfer] Interpreting results from Qdec >>>>>>>>> >>>>>>>>> Courtney, >>>>>>>>> >>>>>>>>> if i understand your question, i think one way to do that is to >>>>>>>>>use qdec >>>>>>>>> to draw a label on the blob of interest, and the run 'map label >>>>>>>>>to >>>>>>>>> subjects', which creates a label file in each subjects label >>>>>>>>>dir, then >>>>>>>>> you can run stats on that with mris_anatomical_stats. >>>>>>>>> >>>>>>>>> (btw, i'm putting this answer on the list, as others may have >>>>>>>>>better >>>>>>>>> ideas.) >>>>>>>>> >>>>>>>>> n. >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> On Mon, 2011-01-03 at 16:38 -0500, Gallen, Courtney (NIH/NIDA) >>>>>>>>>[F] >>>>>>>>> wrote: >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>>> Hi Nick >>>>>>>>>> >>>>>>>>>> Thanks for the prompt reply. Sorry if my questions seem a bit >>>>>>>>>>naïve--this is my first time using Freesurfer. >>>>>>>>>> >>>>>>>>>> A follow up question to your answer for question 1. I see that >>>>>>>>>>the group data will be plotted in Qdec for significant blobs, >>>>>>>>>>but say there is a significant interaction between two variables >>>>>>>>>>and it's not entirely apparent what is driving this interaction. >>>>>>>>>> Is there a way to extract the mean of this blob for each >>>>>>>>>>individual (i.e., treat it as an ROI or something similar) to >>>>>>>>>>determine what's driving the significance? >>>>>>>>>> >>>>>>>>>> Thanks in advance! >>>>>>>>>> Courtney >>>>>>>>>> >>>>>>>>>> -----Original Message----- >>>>>>>>>> From: Nick Schmansky [mailto:ni...@nmr.mgh.harvard.edu] >>>>>>>>>> Sent: Thursday, December 30, 2010 2:44 PM >>>>>>>>>> To: Gallen, Courtney (NIH/NIDA) [F] >>>>>>>>>> Cc: freesurfer@nmr.mgh.harvard.edu >>>>>>>>>> Subject: Re: [Freesurfer] Interpreting results from Qdec >>>>>>>>>> >>>>>>>>>> ans. 1. - the easiest way is to Ctrl- left mouse click on a >>>>>>>>>>blob, and a >>>>>>>>>> plot of the data at that surface vertex will appear. the group >>>>>>>>>>will be >>>>>>>>>> apparent from that (say, demented group is thinner than >>>>>>>>>>non-demented >>>>>>>>>> group). this data is significance data (log p, so '2' is >>>>>>>>>>0.01), so mean >>>>>>>>>> and stdev wouldnt apply in that case. the file 'y.mgh' is the >>>>>>>>>>raw data >>>>>>>>>> of all subjects in the analysis, so you could extract mean and >>>>>>>>>>stdev >>>>>>>>>> from that. >>>>>>>>>> >>>>>>>>>> ans. 2. - slide the 'annotation' opacity slider to show the >>>>>>>>>>annotation >>>>>>>>>> data (cortical parcellation). the ctrl left click will also >>>>>>>>>>put the >>>>>>>>>> region info for that vertex on the lower left of the display. >>>>>>>>>> >>>>>>>>>> see also: >>>>>>>>>> >>>>>>>>>>http://surfer.nmr.mgh.harvard.edu/fswiki/FsTutorial/QdecGroupAnal >>>>>>>>>>ysis >>>>>>>>>> >>>>>>>>>> n. >>>>>>>>>> >>>>>>>>>> On Wed, 2010-12-29 at 10:49 -0500, Gallen, Courtney (NIH/NIDA) >>>>>>>>>>[F] >>>>>>>>>> wrote: >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> >>>>>>>>>>> Hi, >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> I¹m currently running analyses in Qdec and have identified >>>>>>>>>>>areas that >>>>>>>>>>> show significant effects in my contrasts. I have two questions >>>>>>>>>>>related >>>>>>>>>>> to interpreting these results. >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> 1. How can you interpret the effect in each ³blob?² (i.e., >>>>>>>>>>>which >>>>>>>>>>> group has a greater cortical surface area, etc.). Right now, >>>>>>>>>>>all I >>>>>>>>>>> know is that there is an effect in certain areas. Can you >>>>>>>>>>>export this >>>>>>>>>>> data to get means and standard errors? >>>>>>>>>>> >>>>>>>>>>> 2. Is there a way to localize where these effects are? >>>>>>>>>>>E.g., a >>>>>>>>>>> tool that tells you this effect is located in __ area of the >>>>>>>>>>>brain? >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> Thanks in advance >>>>>>>>>>> >>>>>>>>>>> Courtney >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> Courtney Gallen >>>>>>>>>>> >>>>>>>>>>> Post-baccalaureate IRTA >>>>>>>>>>> >>>>>>>>>>> Neuroimaging Research Branch >>>>>>>>>>> >>>>>>>>>>> National Institute on Drug Abuse (IRP) >>>>>>>>>>> >>>>>>>>>>> 251 Bayview Blvd >>>>>>>>>>> >>>>>>>>>>> Suite 200 >>>>>>>>>>> >>>>>>>>>>> Baltimore, MD 21224 >>>>>>>>>>> >>>>>>>>>>> Tel: (443) 740-2631 >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> _______________________________________________ >>>>>>>>>>> Freesurfer mailing list >>>>>>>>>>> Freesurfer@nmr.mgh.harvard.edu >>>>>>>>>>> https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>> The information in this e-mail is intended only for the person >>>>>>>>>>to whom it is >>>>>>>>>> addressed. If you believe this e-mail was sent to you in error >>>>>>>>>>and the e-mail >>>>>>>>>> contains patient information, please contact the Partners >>>>>>>>>>Compliance HelpLine at >>>>>>>>>> http://www.partners.org/complianceline . 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