Filters








2,556 Hits in 8.1 sec

Deformation Field Correction for Spatial Normalization of PET Images Using a Population-Derived Partial Least Squares Model [chapter]

Murat Bilgel, Aaron Carass, Susan M. Resnick, Dean F. Wong, Jerry L. Prince
2014 Lecture Notes in Computer Science  
We present a method for the spatial normalization of PET images that improves their anatomical alignment based on a deformation correction model learned from structural image registration.  ...  We train partial least squares (PLS) regression models within small neighborhoods to relate the PET intensities and deformation fields obtained from the diffeomorphic mapping to the structural image deformation  ...  Acknowledgments This research was supported in part by the Intramural Research Program of the NIH.  ... 
doi:10.1007/978-3-319-10581-9_25 pmid:25383393 pmcid:PMC4222176 fatcat:kw4aji5z6nbs3iec7pwzhknoqy

High-Dimensional Image Registration Using Symmetric Priors

John Ashburner, Jesper L.R. Andersson, Karl J. Friston
1999 NeuroImage  
Bayesian statistics are used to obtain a maximum a posteriori (MAP) estimate of the deformation field.  ...  A high-dimensional model is used, whereby a finite element approach is employed to estimate translations at the location of each voxel in the template image.  ...  Because the mathematics of computing these partial derivatives is algebraicly dense, a C subroutine is provided in Fig. 4 that will compute the derivatives for a single triangular patch.  ... 
doi:10.1006/nimg.1999.0437 pmid:10334905 fatcat:5hvkvamykfavznjiqweof2d4ym

On the modeling, construction, and evaluation of a probabilistic atlas of brain perfusion

Torbjørn Vik, Fabrice Heitz, Izzie Namer, Jean-Paul Armspach
2005 NeuroImage  
The first model is a local model of voxel-by-voxel mean and variance. The second model is a PCA-based global model that accounts for covariance patterns in the images.  ...  takes advantage of information present in databases of normal subjects.  ...  The simulated images are also derived from a single (simulated) PET image.  ... 
doi:10.1016/j.neuroimage.2004.10.019 pmid:15670686 fatcat:p6uv3yyx7nhzxmdhv2fvpupwrm

Mathematical/computational challenges in creating deformable and probabilistic atlases of the human brain

Paul M. Thompson, Roger P. Woods, Michael S. Mega, Arthur W. Toga
2000 Human Brain Mapping  
These mappings generate a local encoding of anatomic variability and are used to create a crisp anatomical image template with highly resolved structures in their mean spatial location.  ...  A disease-specific atlas is constructed to represent the human brain in Alzheimer's disease (AD). Specialized strategies are developed for population-based averaging of anatomy.  ...  After intensity correction and normalization, the reconfigured scans are then averaged on a pixelby-pixel basis to produce a group image template with the average geometry and average image intensity for  ... 
doi:10.1002/(sici)1097-0193(200002)9:2<81::aid-hbm3>3.0.co;2-8 pmid:10680765 fatcat:2sdczc67qjdinjivdjxvmiebwu

Comparison of spatial normalization procedures and their impact on functional maps

Fabrice Crivello, Thorsten Schormann, Nathalie Tzourio-Mazoyer, Per E. Roland, Karl Zilles, Bernard M. Mazoyer
2002 Human Brain Mapping  
The alignment accuracy and impact on functional maps of four spatial normalization procedures have been compared using a set of high resolution brain MRIs and functional PET volumes acquired in 20 subjects  ...  When increasing the spatial resolution to approximately 6 mm, however, differences in localization of activated areas appear as a consequence of the different spatial normalization procedure used, restricting  ...  Papathanassiou for his help in acquiring the anatomical and functional datasets used in this study.  ... 
doi:10.1002/hbm.10047 pmid:12112765 fatcat:6jtduplgnvbdfcqpys7ilkiw2u

An Introduction to Maps and Atlases of the Brain [chapter]

Arthur W. Toga, Paul M. Thompson
2000 Brain Mapping: The Systems  
The Diversity of Brain Maps. Comprehensive maps of brain structure have been derived, at a variety of spatial scales.  ...  Digital mapping of structural and functional image data into a common 3D coordinate space is a prerequisite for many types of brain imaging research, as it supplies a quantitative spatial reference system  ...  As noted earlier, recent studies have used a deformable cryosection atlas to correlate histologic markers of Alzheimer's Disease with metabolic PET signals in vivo, while correcting for tissue deformation  ... 
doi:10.1016/b978-012692545-6/50003-9 fatcat:bou4diffyfgg7njgmi6i4p7wmu

Kinetic Quantitation of Cerebral PET-FDG Studies Without Concurrent Blood Sampling: Statistical Recovery of the Arterial Input Function

F. O'Sullivan, J. Kirrane, M. Muzi, J.N. O'Sullivan, A.M. Spence, D.A. Mankoff, K.A. Krohn
2010 IEEE Transactions on Medical Imaging  
Kinetic quantitation of dynamic positron emission tomography (PET) studies via compartmental modeling usually requires the time-course of the radio-tracer concentration in the arterial blood as an arterial  ...  A fixed population template input function derived from prior experience with directly sampled arterial curves is one possibility.  ...  For the optimization of RSS(A, θ) a standard nonlinear least squares optimization with numerical gradients is used [15] .  ... 
doi:10.1109/tmi.2009.2029096 pmid:19709971 pmcid:PMC4154632 fatcat:il54tt3gs5fmtmnyyy3ledhn2q

Design and Implementation of an Automated Partial Volume Correction in PET: Application to Dopamine Receptor Quantification in the Normal Human Striatum

O. G. Rousset, D. L. Collins, A. Rahmim, D. F. Wong
2008 Journal of Nuclear Medicine  
The considerable effort and potential lack of reproducibility of human-driven PET quantification and partial volume correction (PVC) can be alleviated by use of atlas-based automatic analysis.  ...  Methods: A total of 90 healthy volunteers (age range, 18-46 y) received a single injection of 11 C-raclopride, and automatic segmentation of concomitant structural MR images was performed using a maximum-probability  ...  We thank the staff of the MR and PET units of the Radiology Department at Johns Hopkins for their participation in the collection of the clinical data, Ayon Nandi and Dr.  ... 
doi:10.2967/jnumed.107.048330 pmid:18552147 pmcid:PMC3104499 fatcat:6agejhsutvb2zd3jlma6pxno5i

Disease-Specific Brain Atlases [chapter]

Paul M. Thompson, Michael S. Mega, Arthur W. Toga
2000 Brain Mapping: The Disorders  
National Institute of Mental Health (NINDS/NIMH NS38753), and by a Human Brain Project grant to the International Consortium for Brain Mapping, funded jointly by NIMH and NIDA (P20 MH/DA52176).  ...  Acknowledgments This work was supported by research grants from the National Center for Research Resources (P41 RR13642 and RR05956), the National Institute of Neurological Disorders and Stroke and the  ...  These three-dimensional deformation fields are used to create a crisp anatomical image template with highly-resolved structures in their mean spatial location.  ... 
doi:10.1016/b978-012481460-8/50009-3 fatcat:63fa3fvfdbbf3hq6qm4dy5nwny

Subpopulation Brain Atlases [chapter]

Paul M. Thompson, Michael S. Mega, Arthur W. Toga
2002 Brain Mapping: The Methods  
of Mental Health (NINDS/NIMH NS38753), and by a Human Brain Project grant to the International Consortium for Brain Mapping, funded jointly by NIMH and NIDA (P20 MH/DA52176).  ...  Special thanks go to Neal Jeffries for his advice on longitudinal random effects models, and to our colleagues Katherine Narr, Jay Giedd, Judith Rapoport, Tyrone Cannon, Elizabeth Sowell, Christine Vidal  ...  The notion of least distortion can be formulated precisely using either (1) mean vector fields ; (2) matrix and deformation tensor metrics , (3) using the L 2 -norm on the Hilbert space of deformation  ... 
doi:10.1016/b978-012693019-1/50030-7 fatcat:jyb3d46vhbbp7nfqw3yothneia

Computational anatomy with the SPM software

John Ashburner
2009 Magnetic Resonance Imaging  
Most volumetric studies involve univariate approaches, with a correction for some global measure, such as total brain volume.  ...  Such models of anatomical variability may prove accurate enough for computer assisted diagnoses.  ...  Analyzing deformation fields Usually, when procedures such as SPM are applied to imaging data, the images are all spatially normalized to some common reference space.  ... 
doi:10.1016/j.mri.2009.01.006 pmid:19249168 fatcat:jimplwrt45hltdc4weu6co4pyq

A framework for computational anatomy

Paul M. Thompson, Arthur W. Toga
2002 Computing and Visualization in Science  
We present some novel mathematical strategies for computational anatomy, focusing on the creation of population-based brain atlases.  ...  Efforts to uncover new patterns of altered structure and function in individuals and clinical populations have also led to the new field of computational anatomy  ...  Toga AW, Thompson PM (1997) Measuring, Mapping, and Modeling Brain Structure and Function, SPIE Medical Imaging Symposium, Feb. 1997  ... 
doi:10.1007/s00791-002-0084-6 fatcat:cla6fnu5ybbpngc2gjmcijzavi

Neurofibrillary tau depositions emerge with subthreshold cerebral beta-amyloidosis in down syndrome

Matthew D. Zammit, Dana L. Tudorascu, Charles M. Laymon, Sigan L. Hartley, Paul A. Ellison, Shahid H. Zaman, Beau M. Ances, Sterling C. Johnson, Charles K. Stone, Marwan N. Sabbagh, Chester A. Mathis, William E. Klunk (+3 others)
2021 NeuroImage: Clinical  
PET images were converted to units of standardized uptake value ratios (SUVrs).  ...  A large-sized association that survived adjustment for chronological age, mental age (assessed using the Peabody Picture Vocabulary Test), and imaging site was observed between AβL and AV-1451 within each  ...  Acknowledgements ABC-DS: The Alzheimer's Biomarkers Consortium -Down Syndrome (ABC-DS) project is a longitudinal study of cognition and blood based, genetic and imaging biomarkers of Alzheimer's Disease  ... 
doi:10.1016/j.nicl.2021.102740 pmid:34182407 pmcid:PMC8252122 fatcat:ebi64tr7azg63azzo7s7jafv5i

A Review of Geometric Transformations for Nonrigid Body Registration

M. Holden
2008 IEEE Transactions on Medical Imaging  
This paper provides a comprehensive and quantitative review of spatial transformations models for nonrigid image registration.  ...  This results in two categories, physically based models described by partial differential equations of continuum mechanics (e.g., linear elasticity and fluid flow) and basis function expansions derived  ...  It is typically used for iterative least squares problems to reduces the impact of outliers. The transformation model used depends on the number of voxels in the block.  ... 
doi:10.1109/tmi.2007.904691 pmid:18270067 fatcat:ij3xb2d4hfdfxa3dctj23mk4hm

Accurate High-Speed Spatial Normalization Using an Octree Method

Peter V. Kochunov, Jack L. Lancaster, Peter T. Fox
1999 NeuroImage  
Full-resolution volumetric spatial normalization methods use a high-degree-of-freedom coordinate transform, called a deformation field, for this task.  ...  Processing to fit features at the limiting resolution of a 3-D MR image volume is computationally intensive, limiting broad use of full-resolution regional spatial normalization.  ...  Overall linearity of global scaling within the solid models was assessed from the slope of a least squares linear regression fit of mean measured vs predicted distances.  ... 
doi:10.1006/nimg.1999.0509 pmid:10600418 fatcat:lyd757omqrdy7giyptm534lwhi
« Previous Showing results 1 — 15 out of 2,556 results