OAI Imaging Resources
Welcome to this video on osteoarthritis
initiative imaging.
Before we get started, it's important to
remember that the OAI is a cohort of
almost 4,800 well-characterized
participants that have data and
resources available through three
publicly accessible repositories which
create rich and linkable data sets.
The first repository is the NIMH data
archive or the NDA OAI website. This is
where you can go to download clinical
data, the actual images as well as image
readings.
The genomewide association study is
available through DBGAP and the
biopecimens can be requested from the
biopecimen repository.
For the purpose of this video, we'll be
talking primarily about the resources
available through the NDA OAI website.
All participants had a comprehensive
imaging performed at baseline and annual
follow-up visits through 48month
follow-up. They also had additional
imaging completed at 72 and 96-month
follow-ups.
The most common radioraphs were the
bilateral posterior anterior fixed
flexion knee radioraphs
and participants also underwent a three
Tesla MRI which included sequences like
the sagittal 3D desk which is commonly
used for measuring articular cartilage.
And there's also a 3D flash sequence
available as well as several
two-dimensional sequences such as the
sagittal intermediate weighted fat
suppress sequence.
The most common X-ray in the OAI is the
posterior anterior fixed flexion knee
radioraph which was used for doing
semi-quantitative scoring such as the
Kellgren Lawrence grades as well as for
quantifying joint space width at fixed
locations.
There are other radioraphs available
including fllororoscopically positioned
medio within a subset of the progression
subcohort. These were collected at
baseline 12 and 24 months. Members of
the control subcohort also had lateral
knee views completed at enrollment and
36 months.
And participants also underwent a
fulllim radioraph for measuring hip,
knee, ankle angle at 12, 24 or 36-month
visits.
Participants also had pelvis x-rays and
dominant hand x-rays with some
individuals also having bilateral hand
x-rays available. Other MRIs in include
MRIs of the thigh for muscle assessment
at baseline 24, 48, and 96-month visits.
And a subgroup also underwent additional
imaging at 18 or 30 month OAI visits.
Two groups of the OAI also received
bilateral knee dexa scans and unilateral
hip DEXA. The progression subcohort
members had their adexes performed at 30
or 36-month visit and 48month vis as a
follow-up.
Members of the incidents and control
subcohorts had their DEXA scans
completed at the 72 and 96-month visits.
In addition to the raw images, there is
an array of publicly available readings.
These include semi-quantitative
radiographic assessments of knee and
hips, radiographic assessment of limb
alignment, including femoral tibial
angle and hip knee ankle angle.
Radiographs were also assessed for
quantitative joint space width at fixed
locations.
The MRIs have been read for some
individuals using semi-quantitative knee
scores such as smokes and quantitatively
assessed for articular cartilage mech
changes.
Some of the individuals who had DEXA
scans also had quantitative ticular
morphometry completed.
There's some important tips to consider
when using the publicly available
readings. In each file that has data for
longitudinal or cross-sectional image
readings, you'll find a read project
number. These are important because
longitudinal data within a repro can
typically be merged, but not all
projects should be merged together.
You need to carefully consider the study
design and imaging methods before
merging and analyzing the data. It's
also important to read the OAI
documentation, especially since some of
the documentation will provide
suggestions on how to merge data across
projects or within project.
If you have questions about how to
handle data from multiple read projects,
please contact the PI or the OAI CORE
knowledgebase for assistance.
To access the OAI images, you can go to
the NDA website to download images and
data. The data can include things like
image metadata, for example, who has
which images and when. You can also
download image derived biomarkers such
as the quantitative joint space width
measurements or quantitative articular
cartilage thickness.
You can also go to the NDA website to
download the raw images or the related
documentation and tools for exploring
the data.
The OAI CORE knowledgebase can help you
when you need assistance on creating
imaging sets and we can also help create
and deliver imaging sets via cloud or
hard drives.
If you have questions or need
assistance, please contact the OAI CORE
knowledgebase. Our website is
oaiknowledgebase.com
and you can email us at oaiknowledgebase@umassmed.edu.
Thank you for your time.
Learn about available OAI imaging resources and how to access them.