title: Pydpiper: a flexible toolkit for constructing novel registration pipelines.
abstract: Using neuroimaging technologies to elucidate the relationship between genotype and phenotype and brain and behavior will be a key contribution to biomedical research in the twenty-first century. Among the many methods for analyzing neuroimaging data, image registration deserves particular attention due to its wide range of applications. Finding strategies to register together many images and analyze the differences between them can be a challenge, particularly given that different experimental designs require different registration strategies. Moreover, writing software that can handle different types of image registration pipelines in a flexible, reusable and extensible way can be challenging. In response to this challenge, we have created Pydpiper, a neuroimaging registration toolkit written in Python. Pydpiper is an open-source, freely available software package that provides multiple modules for various image registration applications. Pydpiper offers five key innovations. Specifically: (1) a robust file handling class that allows access to outputs from all stages of registration at any point in the pipeline; (2) the ability of the framework to eliminate duplicate stages; (3) reusable, easy to subclass modules; (4) a development toolkit written for non-developers; (5) four complete applications that run complex image registration pipelines "out-of-the-box." In this paper, we will discuss both the general Pydpiper framework and the various ways in which component modules can be pieced together to easily create new registration pipelines. This will include a discussion of the core principles motivating code development and a comparison of Pydpiper with other available toolkits. We also provide a comprehensive, line-by-line example to orient users with limited programming knowledge and highlight some of the most useful features of Pydpiper. In addition, we will present the four current applications of the code.
authors.affiliation: Mouse Imaging Centre, Hospital for Sick Children Toronto, ON, Canada.
authors.forename: Miriam
authors.initials: M
authors.lastname: Friedel
authors.affiliation: Mouse Imaging Centre, Hospital for Sick Children Toronto, ON, Canada.
authors.forename: Matthijs C
authors.initials: MC
authors.lastname: van Eede
authors.affiliation: Kimel Family Translational Imaging-Genetics Research Laboratory, Research Imaging Centre, Centre for Addiction and Mental Health Toronto, ON, Canada.
authors.forename: Jon
authors.initials: J
authors.lastname: Pipitone
authors.affiliation: Kimel Family Translational Imaging-Genetics Research Laboratory, Research Imaging Centre, Centre for Addiction and Mental Health Toronto, ON, Canada ; Department of Psychiatry, Institute of Biomaterials and Biomedical Engineering, University of Toronto Toronto, ON, Canada ; Rotman Research Institute Toronto, ON, Canada.
authors.forename: M Mallar
authors.initials: MM
authors.lastname: Chakravarty
authors.affiliation: Mouse Imaging Centre, Hospital for Sick Children Toronto, ON, Canada ; Department of Medical Biophysics, University of Toronto Toronto, ON, Canada.
authors.forename: Jason P
authors.initials: JP
authors.lastname: Lerch
keywords: Python; image registration; neuroimaging; pipeline; software