Phase Contrast

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Phase Contrast


a method of producing images of microscopic objects whose structural elements have refractive indexes and optical absorptivities that differ by such small amounts that the elements are indistinguishable in other methods of observing and producing images in a microscope. However, such structural elements introduce light-wave phase shifts that may differ appreciably from one another, producing variations in phase that cannot be detected by either the eye or a photographic emulsion.

Phase contrast consists in the conversion of the phase variations, by means of an optical accessory, into variations in the intensities—that is, in the amplitudes—of the light waves. Such amplitude variations can be detected by a photodetector. Phase contrast was developed by F. Zernike in 1935. (SeeMICROSCOPE: Methods of illumination and observation [microscopy].)


See references under MICROSCOPE.
References in periodicals archive ?
The framework takes phase contrast microscopy image sequences as input, and automatically outputs localized subregions in the sequences where mitosis occurred.
This level of detail is not achievable with MR imaging, though 2D Phase Contrast Imaging is able to show flow characteristics and eventual refluxes through a selected section of the vessel.
There is another way to estimate the energy loss using AFM, which uses the phase contrast images.
In this report, the Europe optical microscopy market has been broadly classified by type, such as inverted microscope, stereo microscope, phase contrast microscope, fluorescence microscope, confocal microscope, near field microscope, and others.
Phase contrast tomography takes advantage of subtle differences in the way radiation - such as X-rays - passes through different substances, in this case papyrus and ink.
5T scanners equipped with standard software and phase contrast magnetic resonance (PCMR) capabilities and analysis packages.
Phase contrast velocity encoded MRI allows one to obtain measures of blood velocity plotted over the cardiac cycle through the valves and the great vessels.
Shoemaker's treatment protocol is available to everyone on line who takes the phase contrast eye test.
A third technique, known as index refraction or phase contrast, provides information on cellular size and density - both factors that play into determination of cancer in laboratory biopsies.
The use of the hanging drop technique means that one does not need an inverted phase contrast microscope to see the cells, i.
In this study, we describe differential phase contrast scanning as a means of achieving quadrature detection of proteins on a spinning disc.
This visualization has been achieved by developing a sample chamber for phase contrast X-ray CT device.