Questions about the clinica data

[fyb99]

Hi, I have finished the converting of ADNI database and I have two questions about the clinical information extraction.

1. In the participants.tsv file located in the BIDS dir, what does the column 'diagnosis_sc' refers to, I find they are different from the diagnostic result of each mri sample in the tsv file of each subfolder.

2. How do you get the diagnosis results. When I converting the OASIS and ADNI dataset, I find the cdr value are highly postively correlated with the diagnosis results. Does clinica get the ground truth by setting thresholds to this metric or something similar, or does clinica extract labels from the data without considering any clinical metrics?

3. Where shall I find about the introduction of the converted metrics?(FAQ, trabscor_bl, etc.) What does baseline refers to? Does it points to the first screening mri sample in time order?

[AliceJoubert]

Hello !

1. "_sc" refers to the screening visit so "diagnosis_sc" refers to the diagnosis at screening only. The diagnosis can be expected to change between sessions. This file can give you more precisions about what we put in the participants.tsv (trabscor_bl too for instance).
2. Indeed, clinica uses the CDR to get a diagnosis result. Basically, clinica maps the values of the CDR which can only be 1, 2 or 3 to a corresponding diagnosis. 1 is associated with CN, 2 to MCI and 3 to AD.
3. The difference between screening and baseline is detailed there in ADNI google group.

[fyb99]

Hi thx for your reply!. I want to further ask that does the mapping procedure of diagnosis results only depend on CDR? To be specific, will the MMSE standard be involved in this process?

[AliceJoubert]

Hello !

I realize I said something wrong last time and double checked ; we do take the "diagnosis" data from ADNI which should itself be established based on both CDR and MMSE.