title: Deformation-based atrophy computation by surface propagation and its application to Alzheimer's disease.
abstract: Obtaining regional volume changes from a deformation field is more precise when using simplex counting (SC) compared with Jacobian integration (JI) due to the numerics involved in the latter. Although SC has been proposed before, numerical properties underpinning the method and a thorough evaluation of the method against JI is missing in the literature. The contributions of this paper are: (a) we propose surface propagation (SP)-a simplification to SC that significantly reduces its computational complexity; (b) we will derive the orders of approximation of SP which can also be extended to SC. In the experiments, we will begin by empirically showing that SP is indeed nearly identical to SC, and that both methods are more stable than JI in presence of moderate to large deformation noise. Since SC and SP are identical, we consider SP as a representative of both the methods for a practical evaluation against JI. In a real application on Alzheimer's disease neuroimaging initiative data, we show the following: (a) SP produces whole brain and medial temporal lobe atrophy numbers that are significantly better than JI at separating between normal controls and Alzheimer's disease patients; (b) SP produces disease group atrophy differences comparable to or better than those obtained using FreeSurfer, demonstrating the validity of the obtained clinical results. Finally, in a reproducibility study, we show that the voxel-wise application of SP yields significantly lower variance when compared to JI.
authors.affiliation: University of Copenhagen , Department of Computer Science, DIKU, Sigursgade 41, Copenhagen 2100, Denmark.
authors.forename: Akshay
authors.initials: A
authors.lastname: Pai
authors.affiliation: University of Copenhagen , Department of Computer Science, DIKU, Sigursgade 41, Copenhagen 2100, Denmark.
authors.forename: Jon
authors.initials: J
authors.lastname: Sporring
authors.affiliation: Biomediq A/S , Fruebjergvej 3, Copenhagen 2100, Denmark.
authors.forename: Sune
authors.initials: S
authors.lastname: Darkner
authors.affiliation: University of Copenhagen, Department of Computer Science, DIKU, Sigursgade 41, Copenhagen 2100, Denmark; Biomediq A/S, Fruebjergvej 3, Copenhagen 2100, Denmark.
authors.forename: Erik B
authors.initials: EB
authors.lastname: Dam
authors.affiliation: Biomediq A/S , Fruebjergvej 3, Copenhagen 2100, Denmark.
authors.forename: Martin
authors.initials: M
authors.lastname: Lillholm
authors.affiliation: Biomediq A/S , Fruebjergvej 3, Copenhagen 2100, Denmark.
authors.forename: Dan
authors.initials: D
authors.lastname: Jørgensen
authors.affiliation: Bioclinica , 7707 Gateway Boulevard, 3rd Floor Newark, California 94560, United States.
authors.forename: Joonmi
authors.initials: J
authors.lastname: Oh
authors.affiliation: Bioclinica , 7707 Gateway Boulevard, 3rd Floor Newark, California 94560, United States.
authors.forename: Gennan
authors.initials: G
authors.lastname: Chen
authors.affiliation: Bioclinica , 7707 Gateway Boulevard, 3rd Floor Newark, California 94560, United States.
authors.forename: Joyce
authors.initials: J
authors.lastname: Suhy
authors.affiliation: Biomediq A/S , Fruebjergvej 3, Copenhagen 2100, Denmark.
authors.forename: Lauge
authors.initials: L
authors.lastname: Sørensen
authors.affiliation: University of Copenhagen, Department of Computer Science, DIKU, Sigursgade 41, Copenhagen 2100, Denmark; Biomediq A/S, Fruebjergvej 3, Copenhagen 2100, Denmark.
authors.forename: Mads
authors.initials: M
authors.lastname: Nielsen
keywords: Jacobian integration; atrophy computation; cube propagation; registration