Abstract #1024
Caveats of non-linear fitting to brain tissue models of diffusion
Ileana O. Jelescu 1 , Jelle Veraart 1 , Els Fieremans 1 , and Dmitry S. Novikov 1
1
Center for Biomedical Imaging, Dept. of
Radiology, NYU Langone Medical Center, New York, New
York, United States
Compared to DTI, white/gray matter models of diffusion
should have improved specificity. However, fit outputs
notoriously suffer from bias and poor precision, with
most models employing simplifying assumptions to
stabilize the fit. Here, we use the example of NODDI to
assess the behavior of nonlinear fitting when all model
parameters are free. We reveal that the typical full
model of brain tissue cannot be reliably determined, due
to a duality of solutions, and to the narrow and shallow
(boomerang-shaped) minimization landscape. Constraining
the fit with fixed parameter values that lack biological
validation is not a trustworthy solution to the problem.
How to access this content:
For one year after publication, abstracts and videos are only open to registrants of this annual meeting. Registrants should use their existing login information. Non-registrant access can be purchased via the ISMRM E-Library.
After one year, current ISMRM & ISMRT members get free access to both the abstracts and videos. Non-members and non-registrants must purchase access via the ISMRM E-Library.
After two years, the meeting proceedings (abstracts) are opened to the public and require no login information. Videos remain behind password for access by members, registrants and E-Library customers.
Click here for more information on becoming a member.
