Stability of gold bead tissue markers.

  title={Stability of gold bead tissue markers.},
  author={Joel Miller and Ethan A. Rossi and Martin Wiesmair and Danielle E Alexander and Orazio Gallo},
  journal={Journal of vision},
  volume={6 5},
Significant soft tissue features in the orbit and elsewhere are not resolved by MRI or any other imaging method. We describe a new method that uses tiny ( approximately 0.1 mm diameter) gold beads as markers to visualize movements of such tissues with high spatial resolution ( approximately 100 microm) and moderate temporal resolution ( approximately 100 ms). We describe bead fabrication, implantation, imaging, and image processing to extract three-dimensional bead coordinates. We then present… Expand
Extraocular muscle deformation assessed by motion-encoded MRI during eye movement in healthy subjects.
Conventional magnetic resonance imaging (MRI) is useful for assessing morphological changes but not for assessing deformations inside homogeneous structures (M. D. Abràmoff, A. P. Van Gils, G. H.Expand
Longitudinal strain estimation in incompressible cylindrical tissues from magnetic resonance imaging
  • Q. Wei, D. Pai
  • Physics, Medicine
  • 2009 Annual International Conference of the IEEE Engineering in Medicine and Biology Society
  • 2009
In this paper, we present a simple approach for estimating the average longitudinal strains from models reconstructed from medical images. It can be used for many incompressible generalizedExpand
Physically Consistent Registration of Extraocular Muscle Models
Building realistic subject-specific models of the orbit from medical images is important in biomechanical simulations to improve our understanding of extraocular mus- cle function and the mechanismExpand
Local deformation of extraocular muscles during eye movement.
Motion-encoded MRI is a useful technique for advancing the understanding of the physiology and pathophysiology of EOMs in humans during eye movement, and was used to study extraocular muscle (EOM) function. Expand
Biomechanical modeling and simulation of human eye movement
Studying human eye movement has significant implications for understanding the oculomotor system and treating vision disorders. Existing models of the oculomotor system either simplify the geometryExpand
Dynamic MRI Encodes Differential Contraction of Extraocular Muscle Segments in Healthy Subjects
Introduction: Nowadays, static MRI and CT are essential clinical tools for detecting mechanical disorders of the orbit [1]. In complex cases, however, there is an additional need to better understandExpand
Physically consistent registration of extraocular muscle models from MRI
  • Qi Wei, D. Pai
  • Mathematics, Medicine
  • 2008 30th Annual International Conference of the IEEE Engineering in Medicine and Biology Society
  • 2008
A constrained optimization problem is solved, which generates parametric surfaces satisfying material property constraints and the resultant anatomically accurate and physically meaningful models are discretized in the corresponding deformed material coordinates and consistent with the real tissue deformation. Expand
Physically-based modeling and simulation of extraocular muscles.
The first three dimensional (3D) biomechanical model which can simulate the dynamics of ocular motility at interactive rates is described and potential clinical applications of such a model are demonstrated. Expand
Understanding and misunderstanding extraocular muscle pulleys.
The stages through which pulley theory has developed are reviewed, distinguishing passive, coordinated, weak differential, and strong differential pulley theories and focusing on points of controversy. Expand
Measuring in vivo internal spinal cord deformations during experimental spinal cord injury using a rat model, radiography, and fiducial markers
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Evidence for fibromuscular pulleys of the recti extraocular muscles.
MRI shows that the paths of recti extraocular muscle (EOM) bellies remain fixed in the orbit during large ocular rotations and across large surgical transpositions of their insertions, implying that recti EOMs pass through pulleys coupled to the orbit and anterior to the muscle bellies, because the insertions must move with the globe. Expand
Evidence for active control of rectus extraocular muscle pulleys.
The authors propose the active-pulley hypothesis, which proposes that by dual insertions the global layer of each rectus EOM rotates the globe while the orbital layer inserts on its pulley to position it linearly and thus influence the EOM's rotational axis. Expand
Effect of transposition surgery on rectus muscle paths by magnetic resonance imaging.
It is proposed that middle and deep orbital tissues (connective tissues and compartmentalized orbital fat) constrain the paths of rectus muscle bellies, preventing them from sliding freely to follow their transposed insertions. Expand
Spatial Aspects of Orbital Musculo-Fibrous Tissue in Man
This monograph presents a new and somewhat unusual anatomical approach to dissecting the orbit from in front, and by careful dissection a highly organized connective tissue system was discovered. Expand
Functional anatomy of normal human rectus muscles
Computer-aided reconstructions of extraocular muscles, reflecting the data of four normal adult subjects, produced clear pictures of the rectus muscles and optic nerve, and yielded data on muscle paths and cross-sections. Expand
Quantitative magnetic resonance morphometry of extraocular muscles: a new diagnostic tool in paralytic strabismus.
A new technique employing high-resolution, surface coil magnetic resonance imaging to quantify extraocular muscle size and contractility is developed and permits insight intoextraocular muscle function in complex strabismus cases. Expand
Active pulleys: magnetic resonance imaging of rectus muscle paths in tertiary gazes.
The active-pulley hypothesis prediction of coordinated anteroposterior shifting of EOM pulleys with gaze is quantitatively supported by changes in EOM path inflections among tertiary-gaze positions. Expand
Extraocular muscle sideslip and orbital geometry in monkeys
It is found that as the eye rotates vertically over 50 deg (+/- 25 deg), the point of tangency of the LR with the globe slips an average of 5.1 mm vertically with respect to the globe, allowing this point--and so the muscle plane--to remain approximately fixed relative to the orbit. Expand
STRANDS: Interactive Simulation of Thin Solids using Cosserat Models
  • D. Pai
  • Mathematics, Computer Science
  • Comput. Graph. Forum
  • 2002
It is shown that models based on the Cosserat theory of elastic rods are very well suited for interactive simulation of these objects. Expand
Multiple View Geometry in Computer Vision
  • B. Wrobel
  • Computer Science
  • Künstliche Intell.
  • 2001
This book is referred to read because it is an inspiring book to give you more chance to get experiences and also thoughts and it will show the best book collections and completed collections. Expand