Question
Question Posted 02/23/26:
I have a question regarding the ADNI tables and a discrepancy I encountered. I initially built an ADNI3 dMRI cohort using ARC Builder and merged demographic and clinical information for these subjects. While some subjects had missing demographic data, that was expected.
I then attempted to match the unique PTIDs from this cohort with those in the dMRI acquisition table filtered for Siemens and Philips scanners. From the table generated via ARC Builder (“My Table”), I first restricted the data to BL scans only, since I am interested in subjects whose first (baseline) dMRI scan occurred in ADNI3, not earlier phases. This resulted in 815 subjects.
Next, I downloaded the dMRI acquisition table, filtered it to Siemens and Philips scanners, and further filtered by INI and YR1 visit codes. However, the resulting PTIDs did not align with those in my original table. When I filtered the acquisition table to INI scans only—which I assumed correspond to BL scans—the number of subjects dropped substantially. In addition, several PTIDs present in my original table were missing from the acquisition table, and I confirmed that these subjects were not listed under GE scanners either.
My question is whether the acquisition table should be filtered to include both INI and YR1 scans as equivalents of BL scans in table 1, or whether there is a more appropriate approach to identifying ADNI3 baseline dMRI scans acquired on Siemens and Philips scanners.
I have a question regarding the ADNI tables and a discrepancy I encountered. I initially built an ADNI3 dMRI cohort using ARC Builder and merged demographic and clinical information for these subjects. While some subjects had missing demographic data, that was expected.
I then attempted to match the unique PTIDs from this cohort with those in the dMRI acquisition table filtered for Siemens and Philips scanners. From the table generated via ARC Builder (“My Table”), I first restricted the data to BL scans only, since I am interested in subjects whose first (baseline) dMRI scan occurred in ADNI3, not earlier phases. This resulted in 815 subjects.
Next, I downloaded the dMRI acquisition table, filtered it to Siemens and Philips scanners, and further filtered by INI and YR1 visit codes. However, the resulting PTIDs did not align with those in my original table. When I filtered the acquisition table to INI scans only—which I assumed correspond to BL scans—the number of subjects dropped substantially. In addition, several PTIDs present in my original table were missing from the acquisition table, and I confirmed that these subjects were not listed under GE scanners either.
My question is whether the acquisition table should be filtered to include both INI and YR1 scans as equivalents of BL scans in table 1, or whether there is a more appropriate approach to identifying ADNI3 baseline dMRI scans acquired on Siemens and Philips scanners.
Response posted 02/23/26 by Rob Reid:
I shouldn't really comment on the appropriateness of your query since only you know what you are trying to get, but I can offer a much better way to filter by manufacturer, and a couple of admittedly loaded comments that might simplify things.
To filter by manufacturer, click on Images, Key MRI -> SCANNER_MANUFACTURER under Secondary Variables.
Comments:
* Why select just Siemens and Philips? You will have nearly as much work to harmonize between them as if you included GE.
* ADNI is an ongoing study without treatments, so I don't normally pay much attention to "BL", "INI", "YR1", etc.. They have their uses, and you may have yours, but the main difference between a 75 year old who got their 1st scan in ADNI3 and a 75 year old who also had a scan in ADNI2 is that the ADNI2 participant has an earlier scan, which you can choose to use or not. Maybe this somewhat arbitrary difference between people who enrolled in earlier stages and newcomers is what you are seeing?
To filter by manufacturer, click on Images, Key MRI -> SCANNER_MANUFACTURER under Secondary Variables.
Comments:
* Why select just Siemens and Philips? You will have nearly as much work to harmonize between them as if you included GE.
* ADNI is an ongoing study without treatments, so I don't normally pay much attention to "BL", "INI", "YR1", etc.. They have their uses, and you may have yours, but the main difference between a 75 year old who got their 1st scan in ADNI3 and a 75 year old who also had a scan in ADNI2 is that the ADNI2 participant has an earlier scan, which you can choose to use or not. Maybe this somewhat arbitrary difference between people who enrolled in earlier stages and newcomers is what you are seeing?
Response posted 02/23/26 by ADNI MRI Core:
Thank you for your question to the MRI Core.
As your request seems to be more focused on technical aspect of curating your download to fit your specific needs, we recommend that you contact the help desk at LONI to further assist with your question concerning using the ARC builder tool within the LONI website.
They can be contacted by emailing: data.coordinator@loni.usc.edu
Thank you
As your request seems to be more focused on technical aspect of curating your download to fit your specific needs, we recommend that you contact the help desk at LONI to further assist with your question concerning using the ARC builder tool within the LONI website.
They can be contacted by emailing: data.coordinator@loni.usc.edu
Thank you
