Holographic tomography: techniques and biomedical applications [Invited]

Abstract

Holographic tomography (HT) is an advanced label-free optical microscopic imaging method used for biological studies. HT uses digital holographic microscopy to record the complex amplitudes of a biological sample as digital holograms and then numerically reconstruct the sample’s refractive index (RI) distribution in three dimensions. The RI values are a key parameter for label-free bio-examination, which correlate with metabolic activities and spatiotemporal distribution of biophysical parameters of cells and their internal organelles, tissues, and small-scale biological objects. This article provides insight on this rapidly growing HT field of research and its applications in biology. We present a review summary of the HT principle and highlight recent technical advancement in HT and its applications.

Dehydration of plant cells shoves nuclei rotation allowing for 3D phase-contrast tomography

“…On the other hand, a too rapid and not natural change of the cytoplasmic balance within the cell could provoke tiny deformations to the nucleus, thus affecting tomographic reconstructions. As an alternative solution, we could reduce the data acquisition time, and consequently collect limited angle views, but a more sophisticated reconstruction algorithm, able to preserve the tomography accuracy, is needed 59 . However, as pointed out in the section 2.4, our method is based on the calculation of nucleus orientations that requires the recognition of at least one minimum−maximum or maximum−minimum transition in the curve of minor axes’ lengths, i.e., a sufficient number of views must be collected.…”

Roadmap on Digital Holography-Based Quantitative Phase Imaging

“…This perturbation approach [43] only allows the measurement of relatively slow volume changes (0.1 Hz) and provides coarse information on the local changes in cell morphometry. Within this framework, holographic tomography approaches [7] present the great advantage of providing the full 3D distribution of the intracellular RI n c (r). Some approaches of tomographic phase microscopy, as presented in this section, enable ways to significantly increase the resolution.…”

“…In the BR approach, a conventional galvanomirror device was adapted to control the illumination beam; later alternative devices such as digital micromirror devices (DMDs) and spatial light modulators (SLM) have evolved for use as the beam steering device in the HT system [101,110,125]. In the BR approach, one can improve the lateral spatial resolution of the imaging system, and in this technique, the spatial frequency collection constraint is commonly referred to as the missing cone problem [7]. Another possibility to achieve HT is by the SR approach; under the static illumination beam, the axial resolution can be improved by capturing a series of sample's information at different rotation angles by rotating the sample [122].…”

“…The various technical approaches available to achieve QPI can be categorized into two groups: first, QPI solutions based on digital holographic microscopy (DHM) [3], holographic tomography (HT) [6,7], spatial interference interferometry (SLIM) [8], gradient light interference microscopy (GLIM) [9], quadriwave lateral shearing interferometry (QLSI) [10], Hilbert phase microscopy (HPM) [11], and Hilbert-Huang phase microscopy (H2PM) [12], and secondly, QPI-based on iterative multi-frame phase retrieval i.e., Fourier ptychography [13,14] or transport of intensity [15].…”

Reconstruction enhancement via projection screening in holographic tomography

“…Limited projection angle holographic tomography (LAHT) is the most popular tool for 3D quantitative phase imaging of cells and tissues [1][2]. LAHT provides a 3D distribution of the refractive index (RI) and its changes in biological microstructures [3].…”