Browsing by Author "Aganj, Iman"
Now showing items 1-17 of 17
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An algorithm for optimal fusion of atlases with different labeling protocols
Iglesias, Juan Eugenio; Sabuncu, Mert Rory; Aganj, Iman; Bhatt, Priyanka; Casillas, Christen; Salat, David H.; Boxer, Adam; Fischl, Bruce R.; Van Leemput, Koen (Elsevier BV, 2015)In this paper we present a novel label fusion algorithm suited for scenarios in which different manual delineation protocols with potentially disparate structures have been used to annotate the training scans (hereafter ... -
as-PSOCT: Volumetric microscopic imaging of human brain architecture and connectivity
Wang, Hui; Magnain, Caroline; Wang, Ruopeng; Dubb, Jay; Varjabedian, Ani; Tirrell, Lee; Stevens, Allison; Augustinack, Jean; Konukoglu, Ender; Aganj, Iman; Frosch, Matthew; Schmahmann, Jeremy; Fischl, Bruce; Boas, David (Elsevier BV, 2018-01)Polarization sensitive optical coherence tomography (PSOCT) with serial sectioning has enabled the investigation of 3D structures in mouse and human brain tissue samples. By using intrinsic optical properties of back-scattering ... -
Automatic clustering and population analysis of white matter tracts using maximum density paths
Prasad, Gautam; Joshi, Shantanu H.; Jahanshad, Neda; Villalon-Reina, Julio; Aganj, Iman; Lenglet, Christophe; Sapiro, Guillermo; McMahon, Katie L.; de Zubicaray, Greig I.; Martin, Nicholas G.; Wright, Margaret J.; Toga, Arthur W.; Thompson, Paul M. (Elsevier BV, 2014-08)We introduce a framework for population analysis of white matter tracts based on diffusion-weighted images of the brain. The framework enables extraction of fibers from high angular resolution diffusion images (HARDI); ... -
Automatic Verification of the Gradient Table in Diffusion-Weighted MRI Based on Fiber Continuity
Aganj, Iman (Springer Science and Business Media LLC, 2018-11-08)In diffusion-weighted magnetic resonance imaging (dMRI), the coordinate systems where the image and the diffusion gradients are represented may be inconsistent, thus impacting the quality of subsequent fiber tracking and ... -
Avoiding Symmetry-Breaking Spatial Non-Uniformity in Deformable Image Registration via a Quasi-Volume-Preserving Constraint
Aganj, Iman; Reuter, Martin; Sabuncu, Mert R.; Fischl, Bruce (Elsevier BV, 2015-02-01)The choice of a reference image typically influences the results of deformable image registration, thereby making it asymmetric. This is a consequence of a spatially non-uniform weighting in the cost function integral that ... -
Diffusion-informed spatial smoothing of fMRI data in white matter using spectral graph filters
Abramian, David; Larsson, Martin; Eklund, Anders; Aganj, Iman; Westin, Carl-Fredrik; Behjat, Hamid (Elsevier BV, 2021-08-15)Brain activation mapping using functional magnetic resonance imaging (fMRI) has been extensively studied in brain gray matter (GM), whereas in large disregarded for probing white matter (WM). This unbalanced treatment has ... -
Evaluation of Denoising Algorithms for Biological Electron Tomography
Narasimha, Rajesh; Aganj, Iman; Bennett, Adam E.; Borgnia, Mario J.; Zabransky, Daniel; Sapiro, Guillermo; McLaughlin, Steven W.; Milne, Jacqueline L.S.; Subramaniam, Sriram (Elsevier BV, 2008-10)Tomograms of biological specimens derived using transmission electron microscopy can be intrinsically noisy due to the use of low electron doses, the presence of a “missing wedge” in most data collection schemes, and ... -
A Hough Transform Global Probabilistic Approach to Multiple-Subject Diffusion MRI Tractography
Aganj, Iman; Lenglet, Christophe; Jahanshad, Neda; Yacoub, Essa; Harel, Noam; Thompson, Paul M.; Sapiro, Guillermo (Elsevier BV, 2011-08)A global probabilistic fiber tracking approach based on the voting process provided by the Hough transform is introduced in this work. The proposed framework tests candidate 3D curves in the volume, assigning to each one ... -
Measurement of Cortical Thickness from MRI by Minimum Line Integrals on Soft-Classified Tissue
Aganj, Iman; Sapiro, Guillermo; Parikshak, Neelroop; Madsen, Sarah K.; Thompson, Paul M. (Wiley, 2009-10) -
Mid-Space-Independent Deformable Image Registration
Aganj, Iman; Iglesias, Juan Eugenio; Reuter, Martin; Sabuncu, Mert Rory; Fischl, Bruce (Elsevier BV, 2017-05-15)Aligning images in a mid-space is a common approach to ensuring that deformable image registration is symmetric – that it does not depend on the arbitrary ordering of the input images. The results are, however, generally ... -
Motion Detection in Diffusion MRI via Online ODF Estimation
Caruyer, Emmanuel; Aganj, Iman; Lenglet, Christophe; Sapiro, Guillermo; Deriche, Rachid (Hindawi Publishing Corporation, 2013)The acquisition of high angular resolution diffusion MRI is particularly long and subject motion can become an issue. The orientation distribution function (ODF) can be reconstructed online incrementally from diffusion-weighted ... -
Multimodal Image Registration Through Simultaneous Segmentation
Aganj, Iman; Fischl, Bruce (IEEE, 2017-11)Multimodal image registration facilitates the combination of complementary information from images acquired with different modalities. Most existing methods require computation of the joint histogram of the images, while ... -
Quantification of Structural Brain Connectivity via a Conductance Model
Frau-Pascual, Aina; Fogarty, Morgan; Fischl, Bruce; Yendiki, Anastasia; Aganj, Iman (Elsevier, 2019-04-01)Connectomics has proved promising in quantifying and understanding the effects of development, aging and an array of diseases on the brain. In this work, we propose a new structural connectivity measure from diffusion MRI ... -
Quantification of Volumetric Morphometry and Optical Property in the Cortex of Human Cerebellum at Micrometer Resolution
Liu, Chao J.; Ammon, William; Siless, Viviana; Fogarty, Morgan; Wang, Ruopeng; Atzeni, Alessia; Aganj, Iman; Iglesias, Juan Eugenio; Zöllei, Lilla; Fischl, Bruce; Schmahmann, Jeremy D.; Wang, Hui (Elsevier BV, 2021-12-01)The surface of the human cerebellar cortex is much more tightly folded than the cerebral cortex. Volumetric analysis of cerebellar morphometry in magnetic resonance imaging studies suffers from insufficient resolution, and ... -
Radius-optimized efficient template matching for lesion detection from brain images
Koley, Subhranil; Dutta, Pranab K.; Aganj, Iman (Springer Science and Business Media LLC, 2021-06-02) -
Reconstruction of the Orientation Distribution Function in Single and Multiple Shell Q-Ball Imaging within Constant Solid Angle
Aganj, Iman; Lenglet, Christophe; Sapiro, Guillermo; Yacoub, Essa; Ugurbil, Kamil; Harel, Noam (Wiley, 2010-08)Q-ball imaging (QBI) is a high angular resolution diffusion imaging (HARDI) technique which has been proven very successful in resolving multiple intravoxel fiber orientations in MR images. The standard computation of the ... -
Unsupervised Medical Image Segmentation Based on the Local Center of Mass
Aganj, Iman; Harisinghani, Mukesh; Weissleder, Ralph; Fischl, Bruce (Springer Science and Business Media LLC, 2018-08-29)Image segmentation is a critical step in numerous medical imaging studies, which can be facilitated by automatic computational techniques. Supervised methods, although highly effective, require large training datasets of ...