title: Computational Shape Models Characterize Shape Change of the Left Atrium in Atrial Fibrillation.
abstract: Shape change of the left atrium (LA) and LA appendage in atrial fibrillation (AF) patients is hypothesized to be linked to AF pathology and to play a role in thrombogenesis; however, many aspects of shape variation in the heart are poorly understood. To date, studies of the LA shape in AF have been limited to empirical observation and summary metrics, such as volume and its likeness to a sphere. This paper describes a more comprehensive approach to the study of the LA shape through the use of computationally derived statistical shape models. We describe practical approaches that we have developed to extract shape parameters automatically from the three-dimensional MR images of the patient. From these images and our techniques, we can produce a more comprehensive description of LA geometric variability than that has been previously possible. We present the methodology and results from two examples of specific analyses using shape models: (1) we describe statistically significant group differences between the normal control and AF patient populations (n = 137) and (2) we describe characteristic shapes of the LA appendage that are associated with the risk of thrombogenesis determined by transesophageal echocardiography (n = 203).
authors.affiliation: Scientific Computing and Imaging Institute, University of Utah, Salt Lake City, UT, USA. ; Comprehensive Arrhythmia Research and Management Center, University of Utah, Salt Lake City, UT, USA.
authors.forename: Joshua
authors.initials: J
authors.lastname: Cates
authors.affiliation: University of Utah School of Medicine, University of Utah, Salt Lake City, UT, USA.
authors.forename: Erik
authors.initials: E
authors.lastname: Bieging
authors.affiliation: Comprehensive Arrhythmia Research and Management Center, University of Utah, Salt Lake City, UT, USA.
authors.forename: Alan
authors.initials: A
authors.lastname: Morris
authors.affiliation: Comprehensive Arrhythmia Research and Management Center, University of Utah, Salt Lake City, UT, USA.
authors.forename: Gregory
authors.initials: G
authors.lastname: Gardner
authors.affiliation: Comprehensive Arrhythmia Research and Management Center, University of Utah, Salt Lake City, UT, USA. ; University of Utah School of Medicine, University of Utah, Salt Lake City, UT, USA.
authors.forename: Nazem
authors.initials: N
authors.lastname: Akoum
authors.affiliation: Comprehensive Arrhythmia Research and Management Center, University of Utah, Salt Lake City, UT, USA. ; University of Utah School of Medicine, University of Utah, Salt Lake City, UT, USA. ; Utah Center for Advanced Imaging Research, University of Utah, Salt Lake City, UT, USA.
authors.forename: Eugene
authors.initials: E
authors.lastname: Kholmovski
authors.affiliation: Comprehensive Arrhythmia Research and Management Center, University of Utah, Salt Lake City, UT, USA. ; University of Utah School of Medicine, University of Utah, Salt Lake City, UT, USA.
authors.forename: Nassir
authors.initials: N
authors.lastname: Marrouche
authors.affiliation: Comprehensive Arrhythmia Research and Management Center, University of Utah, Salt Lake City, UT, USA. ; University of Utah School of Medicine, University of Utah, Salt Lake City, UT, USA.
authors.forename: Christopher
authors.initials: C
authors.lastname: McGann
authors.affiliation: Scientific Computing and Imaging Institute, University of Utah, Salt Lake City, UT, USA. ; Comprehensive Arrhythmia Research and Management Center, University of Utah, Salt Lake City, UT, USA. ; Department of Bioengineering, University of Utah, Salt Lake City, UT, USA.
authors.forename: Rob S
authors.initials: RS
authors.lastname: MacLeod
keywords: atrial fibrillation; cardiac MRI; left atrium; left-atrial appendage; morphometrics; statistical shape modeling