Dual-axis Tomography
Dual-axis Tomography - Related Videos
01:37
Hypothalamic-Pituitary Axis
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2019
The response to stress—be it physical or psychological, acute or chronic—involves activation of the Hypothalamic-Pituitary-Adrenal (HPA) axis. The HPA axis is part of the neuroendocrine system because it involves both neuronal and hormonal communication. Its function is to regulate homeostatic systems—metabolic, cardiovascular, and immune—providing the necessary means to respond to a stressor. What Happens During Stress In response to stress, the neurons in the hypothalamus release...
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Doppler Optical Coherence Tomography of Retinal Circulation
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2012
Total retinal blood flow is measured by Doppler optical coherence tomography and semi-automated grading software.
01:06
Parallel-axis Theorem
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2025
The parallel-axis theorem provides a convenient and quick method of finding the moment of inertia of an object about an axis parallel to the axis passing through its center of mass. Consider a thin rod as an example. There is a striking similarity between the process of finding the moment of inertia of a thin rod about an axis through its middle, where the center of mass lies, and about an axis through its end using the conventional method. In the conventional method, the concept of linear mass...
01:16
Perpendicular-Axis Theorem
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2025
The perpendicular-axis theorem states that the moment of inertia of a planar object about an axis perpendicular to its plane is equal to the sum of the moments of inertia about two mutually perpendicular concurrent axes lying in the plane of the body. Consider a circular disc of mass M and radius R lying along an x-y plane. The origin lies at the center of the disc, and the z-axis is perpendicular to the disc's plane. All three axes coincide at the disc's center. The moment of inertia of this...
16:44
Born Normalization for Fluorescence Optical Projection Tomography for Whole Heart Imaging
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Cited by 15 •
2009
We suggest a Born normalized approach for Optical Projection Tomography (BnOPT) that accounts for the absorption properties of imaged samples to obtain accurate and quantitative fluorescence tomographic reconstructions. We use the proposed algorithm to reconstruct the fluorescence molecular probe distribution within small animal organs.
FAQs
The two tilt series sample the specimen from different orientations, so their projections provide complementary angular information. Combining those datasets gives the reconstruction more complete directional coverage than either series alone. This matters because cellular features can extend through three dimensions; improved sampling helps represent their spatial relationships more faithfully and limits distortions associated with incomplete angular coverage.
Missing-wedge artifacts arise when available projections do not cover every angular direction, which can distort the reconstructed volume. Dual-axis acquisition addresses this limitation by adding a second tilt series around an axis perpendicular to the first. The combined projections improve angular sampling, making the resulting three-dimensional representation less vulnerable to distortions caused by incomplete directional information.
Because the reconstructed volume preserves three-dimensional organization, investigators can examine membranes, organelles, cytoskeletal elements, and macromolecular assemblies in relation to one another. The value is not limited to identifying individual components: the method shows how these structures are arranged within cellular space, providing ultrastructural context that projection images alone cannot provide.
Compared with conventional two-dimensional microscopy, the approach provides volumetric rather than planar information. That distinction allows researchers to assess the spatial arrangement of cellular and molecular features instead of interpreting each feature only within a single image plane. Dual-axis sampling further supports this three-dimensional view by reducing artifacts that could otherwise obscure or misrepresent structure.
A typical workflow begins by collecting electron microscopy projections while the specimen tilts around one axis, then repeating acquisition around a perpendicular axis. The two tilt series are combined computationally to reconstruct the volume. The central procedural requirement is coordinated acquisition from both orientations, because the complementary projections supply the angular information used for the three-dimensional result.
The resulting volumes can reveal nanometer-scale organization of membranes, organelles, cytoskeletal elements, and macromolecular assemblies. Researchers can use these reconstructions to examine where structures occur relative to one another and to identify three-dimensional architectural patterns. Such outcomes are especially valuable when a biological question depends on organization through the cell rather than appearance in a flat image.
It is suited to studies of cell architecture, host-pathogen interactions, developmental processes, and structural changes associated with disease. In each setting, the method contributes a three-dimensional ultrastructural view: it can connect cellular components with their surrounding organization and help characterize structural differences that are difficult to capture with conventional two-dimensional microscopy.