Sparse Decomposition and Modeling of Anatomical Shape Variation

Karl Sjostrand, Egill Rostrup, Charlotte Ryberg, Rasmus Larsen, Colin Studholme, Hansjoerg Baezner, Jose Ferro, Franz Fazekas, Leonardo Pantoni, Domenico Inzitari, Gunhild Waldemar
2007 IEEE Transactions on Medical Imaging  
Recent advances in statistics have spawned powerful methods for regression and data decomposition that promote sparsity, a property that facilitates interpretation of the results. Sparse models use a small subset of the available variables and may perform as well or better than their full counterparts if constructed carefully. In most medical applications, models are required to have both good statistical performance and a relevant clinical interpretation to be of value. Morphometry of the
more » ... s callosum is one illustrative example. This paper presents a method for relating spatial features to clinical outcome data. A set of parsimonious variables is extracted using sparse principal component analysis, producing simple yet characteristic features. The relation of these variables with clinical data is then established using a regression model. The result may be visualized as patterns of anatomical variation related to clinical outcome. In the present application, landmark-based shape data of the corpus callosum is analyzed in relation to age, gender, and clinical tests of walking speed and verbal fluency. To put the data-driven sparse principal component method into perspective, we consider two alternative techniques, one where features are derived using a model-based wavelet approach, and one where the original variables are regressed directly on the outcome. Index Terms-Corpus callosum (CC), decomposition, Leukoaraiosis And DISability in the elderly (LADIS), principal component analysis (PCA), shape analysis, sparse.
doi:10.1109/tmi.2007.898808 pmid:18092733 fatcat:k73zdvkpqjeere3doxv6ss5tca