Towards Regional Elastography of Intracranial Aneurysms

Balocco, Simone; Cámara, Óscar; Frangi, Alejandro F.

doi:10.1007/978-3-540-85990-1_16

Cited by 8 publications

(7 citation statements)

References 10 publications

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“…The equations were solved by finite element analysis using COMSOL Multiphysics V3.4 (COMSOL Inc., Burlington, MA). Details of the modeling can be found in [35]. To the best of our knowledge, in vivo measurements of such properties close to cerebral aneurysms are not available in the literature.…”

Section: Digital Phantom Experimentsmentioning

confidence: 99%

Morphodynamic Analysis of Cerebral Aneurysm Pulsation From Time-Resolved Rotational Angiography

Zhang

Villa‐Uriol²,

Craene³

et al. 2009

IEEE Trans. Med. Imaging

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Abstract-This paper presents a technique to estimate and model patient-specific pulsatility of cerebral aneurysms over one cardiac cycle, using 3D rotational X-ray angiography (3DRA) acquisitions. Aneurysm pulsation is modeled as a time varying -spline tensor field representing the deformation applied to a reference volume image, thus producing the instantaneous morphology at each time point in the cardiac cycle. The estimated deformation is obtained by matching multiple simulated projections of the deforming volume to their corresponding original projections. A weighting scheme is introduced to account for the relevance of each original projection for the selected time point. The wide coverage of the projections, together with the weighting scheme, ensures motion consistency in all directions. The technique has been tested on digital and physical phantoms that are realistic and clinically relevant in terms of geometry, pulsation and imaging conditions. Results from digital phantom experiments demonstrate that the proposed technique is able to recover subvoxel pulsation with an error lower than 10% of the maximum pulsation in most cases. The experiments with the physical phantom allowed demonstrating the feasibility of pulsation estimation as well as identifying different pulsation regions under clinical conditions. Index Terms-Image registration, motion analysis, three-dimensional rotational angiography, X-ray imaging.

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Section: Digital Phantom Experimentsmentioning

confidence: 99%

Morphodynamic Analysis of Cerebral Aneurysm Pulsation From Time-Resolved Rotational Angiography

Zhang

Villa‐Uriol²,

Craene³

et al. 2009

IEEE Trans. Med. Imaging

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“…A real-time performance has been reported using this direct method with a simplified 2D domain that assumes homogeneous material within a region [13]. Another type of method uses iterative optimization to minimize the error in the displacement field generated by the simulator [14], [15], [16]. Although slower than directly solving the inverse problem, this type of method does not assume linearity of the underlying physical model.…”

Section: Introductionmentioning

confidence: 99%

Simulation-Based Joint Estimation of Body Deformation and Elasticity Parameters for Medical Image Analysis

Lee

Foskey

Niethammer

et al. 2012

IEEE Trans. Med. Imaging

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Estimation of tissue stiffness is an important means of noninvasive cancer detection. Existing elasticity reconstruction methods usually depend on a dense displacement field (inferred from ultrasound or MR images) and known external forces. Many imaging modalities, however, cannot provide details within an organ and therefore cannot provide such a displacement field. Furthermore, force exertion and measurement can be difficult for some internal organs, making boundary forces another missing parameter. We propose a general method for estimating elasticity and boundary forces automatically using an iterative optimization framework, given the desired (target) output surface. During the optimization, the input model is deformed by the simulator, and an objective function based on the distance between the deformed surface and the target surface is minimized numerically. The optimization framework does not depend on a particular simulation method and is therefore suitable for different physical models. We show a positive correlation between clinical prostate cancer stage (a clinical measure of severity) and the recovered elasticity of the organ. Since the surface correspondence is established, our method also provides a non-rigid image registration, where the quality of the deformation fields is guaranteed, as they are computed using a physics-based simulation.

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“…Alternatively, the displacement field can be found with a modified MRI machine in tune with a mechanical vibration of tissues [10,20]. Once the deformation field and external forces are known, the material properties can be found by solving a leastsquares problem [41], assuming that the physical model is linear, or by using iterative optimization algorithms to minimize the error in the deformation field [2,13,28]. Although slower than directly solving the inverse problem, these iterative methods do not require linearity of the underlying model and are therefore suitable for any physical model.…”

Section: Previous Workmentioning

confidence: 99%

Fast optimization-based elasticity parameter estimation using reduced models

Lee

2012

Vis Comput

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Elasticity parameters are central to physicallybased animation and medical image analysis. We present an accelerated method to automatically estimate these parameters for a deformation simulator using an iterative optimization framework, given the desired (target) output surface/ shape. During the optimization, the input model is deformed by the simulator, and the distance between the deformed surface and the target surface is minimized numerically. To accelerate the optimization process, we introduce a dimension reduction technique to allow a trade-off between the computational efficiency and desired accuracy. The reduced model is constructed using statistical training with a set of example deformations. To demonstrate this approach, we apply the computational framework to 2D animations of elastic bodies simulated with a linear finite element method. We also present a 3D elastography example, which is simulated with a reduced-dimension finite element model to improve the performance of the optimizer.

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Towards Regional Elastography of Intracranial Aneurysms

Cited by 8 publications

References 10 publications

Morphodynamic Analysis of Cerebral Aneurysm Pulsation From Time-Resolved Rotational Angiography

Morphodynamic Analysis of Cerebral Aneurysm Pulsation From Time-Resolved Rotational Angiography

Simulation-Based Joint Estimation of Body Deformation and Elasticity Parameters for Medical Image Analysis

Fast optimization-based elasticity parameter estimation using reduced models

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