ABIDE II

ABIDE II is the second collection of the Autism Brain Imaging Data Exchange. It was set up with NIMH funding to add a larger and more deeply phenotyped sample to ABIDE I, with a focus on measures of core autism symptoms and co-occurring conditions. The data were released through the 1000 Functional Connectomes Project / INDI in June 2016, with release updates in September 2016 and March 2017.

Composition

The ABIDE II page lists 1,114 datasets from 521 people with autism spectrum disorder and 593 controls, aged 5 to 64 years, across 19 collections. Ten institutions also contributed to ABIDE I and seven are new. The data descriptor covers the 17 collections received by June 2016 (1,044 datasets, median age 11.7 years). Two further longitudinal collections hold a second scan, taken one to four years later, for 38 people whose first scan is in ABIDE I. Phenotypic files give diagnosis, age and sex for everyone, plus IQ, handedness and, for many collections, ADOS, ADI-R, SRS, comorbid psychiatric diagnoses and medication.

Acquisition

Every person has at least one T1-weighted anatomical scan and a resting-state fMRI run, except one person in the IP_1 collection who has only the anatomical scan. Six collections also share diffusion MRI, and one adds FLAIR. All collections used 3 T Siemens, Philips or GE scanners, except IP_1 at 1.5 T. Resting-state runs last five to eight minutes, and eye instructions differ between sites. Faces and ears were removed from high-resolution images before release.

Annotations

There are no image labels. Diagnoses come from each site's own assessment, mostly clinical judgment combined with ADOS and ADI-R. Quality metrics from the Preprocessed Connectome Project protocol (SNR, CNR, framewise displacement and others) are released for the scans.

Known limitations

• Collections were acquired for separate studies, so inclusion criteria, protocols and age ranges differ by site and site effects are large.
• Data were shared regardless of quality, including scans with heavy motion.
• Females make up 15% of the autism group and 31% of the controls in the paper's sample.
• Comparisons with ABIDE I need care: some collections continue ABIDE I protocols, others are independent.
• Per-modality counts are only published for the 17 collections in the paper.