Imaging Data

AIBL subjects with MR and PIB/PET imaging data constitute about 25% of the full AIBL cohort. Imaging data (MR and PET/PIB) are provided through the LONI Image Data Archive (IDA).

MR images

The MR data are provided in DICOM format. Only raw data are provided; no processed images or analysed results are provided.

ADNI-compliant Series only are provided. These are:

  • MPRAGE_ADNI_confirmed
  • Axial_PD-T2_TSE_confirmed

Some of the oldest baseline AIBL data was acquired without ADNI-compliant Series and these data are not provided. There are both 3T (site=1) and 1.5T (site=2) data.

PET images

The PET/PIB data are provided in DICOM format. Only raw data are provided; no processed images or analysed results are provided.

Generally, 6 frames each of 5min are acquired, starting at 40min after injection of the PIB biomarker. However, some early data were acquired with 10min frames. Only summed images are provided (i.e. multi-frame images are not provided).

To be compliant with ADNI, the images have been re-summed (no inter-frame registration) starting with the first frame consistent with a start time of 50min after injection of the PIB biomarker. Provided there is a minimum of 15min of data available to sum, all remaining frames are then summed, even if they extend beyond the 70min window (as this provides the best signal-to-noise ratio possible in the images). Images with less than 15min of data consistent with the 50-70min window are not provided.

The meta-data describing the PET images is supplied in the table aibl_pibmeta.csv (available via the non-imaging download page. The following items should be noted (see also this table).

  1. The element PBNMFRAM1 gives the total number of frames that were summed
  2. The element PBDURATN1 gives the duration (in sec) of individual frames included in the sum

Meta-Data

Users should not rely on the DICOM headers of any downloaded image data for correct subject meta-data such as date of birth, age and gender. Users should always refer to the values in the non-imaging tables (e.g. demographics) supplied in the non-imaging section However, the subject meta-data (age, gender) available through the LONI/IDA query interface are correct.