NACC research structural MRI

NACC MRI sample characteristics

Modality	MRI
MRI types	T1-weighted FLAIR DTI T2 Other
MRI data format	DICOM (.dcm) image files
MRI package format	.zip
Method of MRI collection	ADCs voluntarily submit available images to NACC. Image-acquisition and data-collection protocols vary by ADC. Retrospective and prospective data collections is ongoing.
Image acquisition period	2005 – present
Subjects	ADC subjects enrolled in the Uniform Data Set (UDS)
Clinical diagnoses	Normal cognition, MCI, dementia
Linked genotype data	Available from ADGC
Longitudinal MRIs	Available for some subjects

The NACC Research Structural MRI Database is a large, freely available sample of MRIs that are linked to the standardized UDS and NP data, as well as genotype data from ADGC.

MRIs at NACC are most appropriately described as a convenience sample of images, voluntarily submitted by several Alzheimer's Disease Centers. Imaging data collection and acquisition protocols vary by ADC; thus, packages of MRI files at NACC may include T1-weighted, FLAIR, DTI, T2, or other MR series (and any combination thereof), and subjects may or may not have multiple scan sessions in the NACC database.

Accessing MRI image files

TO VIEW A SAMPLE OF MRIs meeting specified image and subject criteria:
NACC's MRI query system	Available data:	Researcher requirements:
	• Sample size estimation: – Number of MRI files meeting criteria – Number of unique UDS subject IDS meeting criteria • Links to download a sample of 10 or fewer MRIs meeting criteria	Name Email address Acknowledgment of NACC's confidentiality agreement Visualization software
TO REQUEST IMAGE FILES for analysis and publication purposes:
NACC data file request	Available data:	Researcher requirements:
	"Packages" of DICOM MRIs archived by subject ID and MRI date (.zip), delivered via a cloud-based distribution system and linked to any requested UDS, FTLD, or NP data. Note: Additional image types not requested may be included in the package.	Name Email address Proposal title Brief project description and specific aims Acknowledgment of NACC's confidentiality agreement Visualization software

Anyone may access a sample of MRI files at NACC through NACC's MRI Query System; however, to open and view the images, visualization software is required. Many software packages are available on the web as freeware or free trials and can be located by doing a web search for "DICOM viewer."

Please note that to download images for analysis and publication purposes, a more detailed data request is required.