Instrumentación & Señales 2014 - Jorge Márquez Flores UNAM 1

Imaging (ES: imagenología o imaginología (RAE), FR:

Imagerie) is the formation (physics), recording (technology),

representation or reproduction of an object's outward form;

especially a visual representation (i.e., the formation of an image).

It is extended to 3D and higher-dimensionality information, when

using the term "3D images", or "nD images", instead of volumes or

hyper-volumes, which refer rather to domain information

(coordinates). This list is still incomplete and highly biased to

medical imaging techniques.

Just a few imaging methodologies and technologies:

Basic imaging modalities (2D & 3D): Optical/Laser, Electromagnetism, X-

Ray/CT, MRI, Ultrasound, Radionuclides, Thermography.

Acoustic microscopy is microscopy that employs very high or ultra high

frequency ultrasound. Acoustic microscopes operate nondestructively and

penetrate most solid materials to make visible images of internal features,

including defects such as cracks, delaminations and voids.

Angiography or arteriography. A medical imaging technique used to visualize

the inside, or lumen, of blood vessels and organs of the body, with

particular interest in the arteries, veins and the heart chambers.

Angle-resolved low-coherence interferometry (a/LCI) is an emerging

biomedical imaging technology which uses the properties of scattered light

to measure the average size of cell structures, including cell nuclei. The

technology shows promise as a clinical tool for in situ detection of

dysplatic, or precancerous tissue.

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Annular dark-field imaging is a method of mapping samples in a scanning

transmission electron microscope (STEM). These images are formed by

collecting scattered electrons with an annular dark-field detector.

Aperture synthesis or synthesis imaging is a type of Interferometry that mixes

signals from a collection of telescopes to produce images having the same

angular resolution as an instrument the size of the entire collection. At each

separation and orientation, the lobe-pattern of the interferometer produces

an output which is one component of the Fourier transform of the spatial

distribution of the brightness of the observed object. The image (or "map")

of the source is produced from these measurements. Astronomical

interferometers are commonly used for high-resolution optical, infrared,

submillimetre and radio astronomy observations.

Arthrogram. A series of images, often X-rays, of a joint after injection of a

contrast medium.

Atomic force microscopy (AFM) or scanning force microscopy (SFM) is a very

high-resolution type of scanning probe microscopy, with demonstrated

resolution on the order of fractions of a nanometer, more than 1000 times

better than the optical diffraction limit.

Ballistic photons are the light photons that travel through a scattering (turbid)

medium in a straight line. Also known as ballistic light. If laser pulses are

sent through a turbid medium such as fog or body tissue, most of the

photons are either randomly scattered or absorbed. However, across short

distances, a few photons pass through the scattering medium in straight

lines. These coherent photons are referred to as ballistic photons. Photons

that are slightly scattered, retaining some degree of coherence, are referred

to as snake photons.

Biological imaging may refer to any imaging technique used in biology.

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Bioluminescence imaging (BLI) is a technology developed over the past decade

that allows for the noninvasive study of ongoing biological processes in

small laboratory animals. Recently, bioluminescence tomography (BLT)

has become possible and several systems have become commercially

available.

Bone densitometry or DEXA (Dual-Energy X-Ray Absorptiometry) - with short

scanning times and low X-ray doses, this sensitive equipment can help

identify risk of osteoporosis earlier than ever before.

Bright-field microscopy is the simplest of all the optical microscopy illumination

techniques. Sample illumination is transmitted (i.e., illuminated from below

and observed from above) white light and contrast in the sample is caused

by absorbance of some of the transmitted light in dense areas of the sample.

Bright-field microscopy is the simplest of a range of techniques used for

illumination of samples in light microscopes and its simplicity makes it a

popular technique. The typical appearance of a bright-field microscopy

image is a dark sample on a bright background, hence the name.

Cardiac Ventriculography. A medical imaging test used to determine a patient's

cardiac function in the right, or more typically, left ventricle. Cardiac

ventriculography involves injecting contrast media into the heart's

ventricle(s) to measure the volume of blood pumped. Cardiac

ventriculography can be performed with a radionuclide in radionuclide

ventriculography or with an iodine-based contrast in cardiac chamber

catheterization.

Chemical force microscopy (CFM) is a variation of atomic force microscopy

(AFM) which has become a versatile tool for characterization of materials

surfaces. With AFM, structural morphology is probed using simple tapping

or contact modes that utilize van der Waals interactions between tip and

sample to maintain a constant probe deflection amplitude (constant force

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mode) or maintain height while measuring tip deflection (constant height

mode).

Chemical imaging, is the analytical capability to create a visual image of

components distribution from simultaneous measurement of spectra and

spatial, time information (pictures and video).

Cinematography art or science of motion picture photography. It is the

technique of film photography, including both the shooting and

development of the film.

Computerized Tomography Imaging (CT). or Computed Axial Tomography

(CAT: A CT scan, also known as a CAT scan), is a helical tomography

(latest generation), which traditionally produces a 2D image of the

structures in a thin section of the body. It uses X-rays. It has a greater

ionizing radiation dose burden than projection radiography; repeated scans

must be limited to avoid health effects. CT is based on the same principles

as X-Ray projections but in this case, the patient is enclosed in a

surrounding ring of detectors assigned with 500-1000 scintillation detectors

(fourth-generation X-Ray CT scanner geometry).

Cone beam computed tomography (or CBCT, also referred to as C-arm CT,

cone beam volume CT, or flat panel CT) is a medical imaging technique

consisting of X-ray computed tomography where the X-rays are divergent,

forming a cone.

Confocal laser scanning microscopy (CLSM or LSCM) is a technique for

obtaining high-resolution optical images with depth selectivity. The key

feature of confocal microscopy is its ability to acquire in-focus images from

selected depths, a process known as optical sectioning. Images are acquired

point-by-point and reconstructed with a computer, allowing three-

dimensional reconstructions of topologically complex objects.

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Confocal microscopy is an optical imaging technique used to increase optical

resolution and contrast of a micrograph by adding a spatial pinhole placed

at the confocal plane of the lens to eliminate out-of-focus light It enables

the reconstruction of three-dimensional structures from the obtained

images.

Contrast-enhanced ultrasound (CEUS) is the application of ultrasound contrast

medium to traditional medical sonography. Ultrasound contrast agents rely

on the different ways in which sound waves are reflected from interfaces

between substances. This may be the surface of a small air bubble or a more

complex structure. Commercially available contrast media are gas-filled

microbubbles that are administered intravenously to the systemic

circulation. Microbubbles have a high degree of echogenicity, which is the

ability of an object to reflect the ultrasound waves. The echogenicity

difference between the gas in the microbubbles and the soft tissue

surroundings of the body is immense. Thus, ultrasonic imaging using

microbubble contrast agents enhances the ultrasound backscatter, or

reflection of the ultrasound waves, to produce a unique sonogram with

increased contrast due to the high echogenicity difference. Contrast-

enhanced ultrasound can be used to image blood perfusion in organs,

measure blood flow rate in the heart and other organs, and has other

applications as well.

Corneal topography. Also known as photokeratoscopy or videokeratography,

is a non-invasive medical imaging technique for mapping the surface

curvature of the cornea, the outer structure of the eye. Since the cornea is

normally responsible for some 70% of the eye's refractive power its

topography is of critical importance in determining the quality of vision and

corneal health.

Cryo-electron microscopy (cryo-EM), or electron cryomicroscopy, is a form of

transmission electron microscopy (EM) where the sample is studied at

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cryogenic temperatures (generally liquid nitrogen temperatures). Cryo-EM

is developing popularity in structural biology.

Cryo-electron tomography (cryo-ET or electron cryotomography) is a type of

electron cryomicroscopy where tomography is used to obtain a 3D

reconstruction of a sample from tilted 2D images at cryogenic temperatures.

A cryoelectron tomography can be used to obtain structural details of

complex cellular organizations at subnanometer resolutions.

Dark field microscopy (dark ground microscopy) describes microscopy

methods, in both light and electron microscopy, which exclude the

unscattered beam from the image. As a result, the field around the specimen

(i.e. where there is no specimen to scatter the beam) is generally dark.

Differential interference contrast (DIC) microscopy, also known as Nomarski

Interference Contrast (NIC) or Nomarski microscopy, is an optical

microscopy illumination technique used to enhance the contrast in

unstained, transparent samples. DIC works on the principle of

interferometry to gain information about the optical path length of the

sample, to see otherwise invisible features. A relatively complex lighting

scheme produces an image with the object appearing black to white on a

grey background. This image is similar to that obtained by phase contrast

microscopy but without the bright diffraction halo.

Diffraction topography (short: "topography") is an X-ray imaging technique

based on Bragg diffraction. Diffraction topographic images ("topographs")

record the intensity profile of a beam of X-rays (or, sometimes, neutrons)

diffracted by a crystal. A topograph thus represents a two-dimensional

spatial intensity mapping of reflected X-rays, i.e. the spatial fine structure of

a Bragg spot. This intensity mapping reflects the distribution of scattering

power inside the crystal; topographs therefore reveal the irregularities in a

non-ideal crystal lattice. X-ray diffraction topography is one variant of X-

ray imaging, making use of diffraction contrast rather than absorption

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contrast which is usually used in radiography and computed tomography

(CT).

Diffuse optical imaging (DOI) is a method of imaging using Near Infrared

Spectroscopic (NIRS) or Fluorescence based methods. When used to create

3D volumetric models of the imaged material DOI is referred to as diffuse

optical tomography, whereas 2D imaging methods are classified as diffuse

optical topography.

Diffuse optical tomography. Diffuse Optical Tomography (DOT) and Imaging

(DOI) are non-invasive techniques that utilize light in the near infrared

spectral region to measure the optical properties of physiological tissue. The

techniques rely on the object under study being at least partially light-

transmitting or translucent, so it works best on soft tissues such as breast

and brain tissue.

Diffuse optical topography is an alternative tool in functional near infrared

spectroscopy (fNIRS) since it avoids solving the forward and inverse

computational problems, which are encountered in diffuse optical

tomography. Topography is particularly useful when a sparse array of

optodes is used and depth specificity is not the primary interest.

Diffusion MRI (or dMRI, also Diffusion-weighted imaging) is a magnetic

resonance imaging (MRI) method which came into existence in the mid-

1980s. It allows the mapping of the diffusion process of molecules, mainly

water, in biological tissues, in vivo and non-invasively. Molecular diffusion

in tissues is not free, but reflects interactions with many obstacles, such as

macromolecules, fibers, membranes, etc. Water molecule diffusion patterns

can therefore reveal microscopic details about tissue architecture, either

normal or in a diseased state. Diffusion functional MRI (DfMRI) is a new

field, as it was suggested that with dMRI one could also get images of

neuronal activation in the brain.

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Digital holographic microscopy: DHM™ (DHM is a trademark belongings to

the Swiss company Lyncée Tec SA) is digital holography applied to

microscopy. Digital holographic microscopy distinguishes itself from other

microscopy methods by not recording the projected image of the object.

Instead, the light wave front information originating from the object is

digitally recorded as a hologram, from which a computer calculates the

object image by using a numerical reconstruction algorithm. The image

forming lens in traditional microscopy is thus replaced by a computer

algorithm.

Digital imaging, creating digital images, generally by scanning or through

digital photography.

Disk image, a file which contains the exact content of a data storage medium.

Document imaging, replicating documents commonly used in business.

Doppler echocardiography is a procedure that uses ultrasound technology to

examine the heart or blood vessels. An echocardiogram uses high frequency

sound waves to create an image of the heart while the use of Doppler

technology allows determination of the speed and direction of blood flow

by utilizing the Doppler effect.

Dual-energy X-ray absorptiometry (DXA, previously DEXA) is a means of

measuring bone mineral density (BMD). Two X-ray beams with different

energy levels are aimed at the patient's bones. When soft tissue absorption is

subtracted out, the BMD can be determined from the absorption of each beam

by bone. Dual-energy X-ray absorptiometry is the most widely used and

most thoroughly studied bone density measurement technology.

Dynamic Angiothermography. This technique utilizes thermal imaging but with

important differences with the tele-thermography and contact

thermography, that impact detection performance.

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Echocardiography. When ultrasound is used to image the heart it is referred to

as an echocardiogram. Echocardiography allows detailed structures of the

heart, including chamber size, heart function, the valves of the heart, as well

as the pericardium (the sac around the heart) to be seen.

Elastography. A new imaging modality that maps the elastic properties of soft

tissue. This modality can use ultrasound, magnetic resonance imaging and

tactile imaging.

Electrical Impedance Tomography (EIT) refers to a non-invasive medical

imaging technique in which an image of the conductivity or permittivity of

part of the body is inferred from surface electrode measurements.

Electron microscopy. An electron microscope is a microscope that uses

accelerated electrons as a source of illumination. Because the wavelength of

an electron can be up to 100,000 times shorter than that of visible light

photons, the electron microscope has a higher resolving power than a light

microscope and can reveal the structure of smaller objects. A transmission

electron microscope can achieve better than 50 pm resolution and

magnifications of up to about 10,000,000x whereas most light microscopes

are limited by diffraction to about 200 nm resolution and useful

magnifications below 2000x.

Endomicroscopy is a technique for obtaining histology-like images from inside

the human body in real-time, a process known as ‘optical biopsy’. It

generally refers to fluorescence confocal microscopy, although multi-

photon microscopy and optical coherence tomography have also been

adapted for endoscopic use.

Endoscopic ultrasonography or ultrasound (EUS) or echo-endoscopy is a

medical procedure in which endoscopy (insertion of a probe into a hollow

organ) is combined with ultrasound to obtain images of the internal organs

in the chest and abdomen. It can be used to visualize the walls of these

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organs, or to look at adjacent structures. Combined with Doppler imaging,

nearby blood vessels can also be evaluated.

Endoscopy means looking inside and typically refers to looking inside the body

for medical reasons using an endoscope, an instrument used to examine the

interior of a hollow organ or cavity of the body. Endoscope can also refer

to using a borescope in technical situations where direct line of-sight

observation is not feasible.

Epifluorescence_microscopy. A fluorescence microscope is an optical

microscope that uses fluorescence and phosphorescence instead of, or in

addition to, reflection and absorption to study properties of organic or

inorganic substances. The "fluorescence microscope" refers to any

microscope that uses fluorescence to generate an image, whether it is a

more simple set up like an epifluorescence microscope, or a more

complicated design such as a confocal microscope, which uses optical

sectioning to get better resolution of the fluorescent image.

Fluorescence microscopy. A fluorescence microscope is an optical microscope

that uses fluorescence and phosphorescence instead of, or in addition to,

reflection and absorption to study properties of organic or inorganic

substances. The "fluorescence microscope" refers to any microscope that

uses fluorescence to generate an image, whether it is a more simple set up

like an epifluorescence microscope, or a more complicated design such as a

confocal microscope, which uses optical sectioning to get better resolution

of the fluorescent image.

Fluoroscopy . This method of scanning reduces the patient’s radiation dose and

allows areas of the body to be examined in all directions. This is currently

used in conjunction with MRI for MR Arthrography.

Full spectral imaging is a form of Imaging spectroscopy and is the successor to

Hyperspectral imaging. Full Spectral Imaging was developed to improve

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the capabilities of Earth remote sensing (see also remote sensing).

Hyperspectral imaging acquires data as many contiguous spectral bands.

Full Spectral Imaging (FSI) acquires data as spectral curves. A significant

advantage of FSI over Hyperspectral is a significant reduction in data rate

and volume. FSI extracts and saves only the information that is in the raw

data. The information is contained in the shape of the spectral curves. The

rate at which data is produced by an FSI system is proportional to the

amount of information in the scene/image.

Functional magnetic resonance imaging or functional MRI (fMRI). is a

functional neuroimaging procedure using MRI technology that measures

brain activity by detecting associated changes in blood flow. This technique

relies on the fact that cerebral blood flow and neuronal activation are

coupled. When an area of the brain is in use, blood flow to that region also

increases.

Functional near-infrared spectroscopy. FNIR Is a relatively new non-invasive

imaging technique. NIRS (near infrared spectroscopy) is used for the

purpose of functional neuroimaging and has been widely accepted as a

brain imaging technique.

Gamma camera, also called a scintillation camera or Anger camera, is a device

used to image gamma radiation emitting radioisotopes, a technique known

as scintigraphy. The applications of scintigraphy include early drug

development and nuclear medical imaging to view and analyse images of

the human body or the distribution of medically injected, inhaled, or

ingested radionuclides emitting gamma rays.

Geophysical imaging (several techniques). Seismic-wave imaging is used for

deep soil and rock-bed composition, subterranean rivers, petroleum

reservoirs and ore mining.

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High-resolution computed tomography (HRCT) is computed tomography (CT)

with high resolution. It is used in the diagnosis of various health problems.

For example, HRCT of the lung is a medical diagnostic test used for

diagnosis and assessment of interstitial lung disease. It involves the use of

special computed tomography scanning techniques to assess the lung

parenchyma.

Hoffman modulation contrast (HMC) is a technique for enhancing the contrast

in unstained transparent biological specimens, invented by Dr Robert

Hoffman in 1975. This is achieved by using components in the light path

which convert phase gradients into variations in light intensity. Specimens

thus illuminated have a 3D appearance which renders them more easily

visible. In some specimens, the 3d appearance may be misleading, as a

feature which appears to cast a shadow may not necessarily have distinct

physical geometry.

Holographic interference microscopy (HIM) is holographic interferometry

applied for microscopy for visualization of phase micro-objects. Phase

micro-objects are invisible because they do not change intensity of light,

they insert only invisible phase shifts. The holographic interference

microscopy distinguishes itself from other microscopy methods by using a

hologram and the interference for converting invisible phase shifts into

intensity changes. Digital holographic interference microscopy (DHIM) is

a combination of the holographic interference microscopy with digital

methods of image processing for 3D imaging of phase micro-objects. The

holographic phase-contrast or interference-contrast images (interferograms)

are recorded by a digital camera from which a computer reconstructs 3D

images by using numerical algorithms.

Holography, recording and reproduction of a "light field", using arrays of

coherent light sources, projecting (on to or from) a recording media the

patterns of wave interferences; this allows to include all electromagnetic

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properties of light: magnitude and direction, wavelength spectra,

polarization, phase, etc. Digital holography allows synthesizing such "true"

3D images.

Hyperspectral imaging, like other spectral imaging, collects and processes

information from across the electromagnetic spectrum. The goal of

hyperspectral imaging is to obtain the spectrum for each pixel in the image

of a scene, with the purpose of finding objects, identifying materials, or

detecting processes.

Imaging cycler microscopy (ICM). This microscope is a fully automated

(epi)fluorescence microscope which overcomes the spectral resolution limit

resulting in parameter- and dimension-unlimited fluorescence imaging. The

principle and robotic device was described by Walter Schubert in 1997 and

eversince has been further developed with his co-workers within the human

toponome project. The ICM runs robotically controlled repetitive

incubation-imaging-bleaching cycles with dye-conjugated probe libraries

recognizing target structures in situ (biomolecules in fixed cells or tissue

sections). This results in the transmission of a randomly large number of

distinct biological informations by re-using the same fluorescence channel

after bleaching for the transmission of another biological information using

the same dye which is conjugated to another specific probe, a.s.o. Thereby

noise-reduced quasi-multi channel fluorescence images with reproducible

physical, geometrical, and biophyscial stabilities are generated. The

resulting power of combinatorial molecular discrimination (PCMD) per

data point is given by 65,536k, where 65,536 is the number of grey value

levels (output of a 16-bit CCD camera) and k is the number of co-mapped

biomolecules and/or subdomains per biomolecule(s). High PCMD has been

shown for k = 100, and in principle can be expanded for much higher

numbers of k. In contrast to traditional multi-channel-few parameter

fluorescence microscopy high PCMDs in an ICM lead to high functional

and spatial resolution

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Imaging spectroscopy (also hyperspectral or spectral imaging or chemical

imaging) is similar to color photography, but each pixel acquires many

bands of light intensity data from the spectrum, instead of just the three

bands of the RGB color model. More precisely, it is the simultaneous

acquisition of spatially coregistered images in many spectrally contiguous

bands.

Imaging technology is the application of materials and methods to create,

preserve, or duplicate images.

Infrared microscopy. The term infrared microscope covers two main types of

diffraction-limited microscopy. The first provides optical visualization plus

IR spectroscopic data collection. The second (more recent and more

advanced) technique employs focal plane array detection for infrared

chemical imaging, where the image contrast is determined by the response

of individual sample regions to particular IR wavelengths selected by the

user. IR versions of sub-diffraction microscopy (see above) also exist.

These include IR NSOM and photothermal microspectroscopy. Infrared

(IR) thermal microscopy is a tool for microelectronic temperature

measurement and failure analysis. It is a non-contact measurement

technique which utilises naturally emitted infrared radiation from a sample.

Commercial IR instruments are now available, offering spatial resolutions

down to around 2.5 µm and a range of options including real time

temperature mapping and transient detection.

Interference reflection microscopy or IRM is an optical microscopy technique

that utilizes polarized light to form an image of an object on a glass surface.

The intensity of the signal is a measure of proximity of the object to the

glass surface. This technique can be used to study events at the cell

membrane without the use of a (fluorescent) label in contrast to TIRF

microscopy.

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Interferometric microscopy or Imaging interferometric microscopy is the

concept of microscopy which is related to holography, synthetic-aperture

imaging, and off-axis-dark-field illumination techniques. Interferometric

microscopy allows enhancement of resolution of optical microscopy due to

interferometric (holographic) registration of several partial images

(amplitude and phase) and the numerical combining.

Interferometric synthetic aperture radar, abbreviated InSAR or IfSAR, is a

radar technique used in geodesy and remote sensing. This geodetic method

uses two or more synthetic aperture radar (SAR) images to generate maps

of surface deformation or digital elevation, using differences in the phase of

the waves returning to the satellite or aircraft. The technique can potentially

measure centimetre-scale changes in deformation over spans of days to

years. It has applications for geophysical monitoring of natural hazards, for

example earthquakes, volcanoes and landslides, and in structural

engineering, in particular monitoring of subsidence and structural stability.

Interferometry is a family of techniques in which waves, usually

electromagnetic, are superimposed in order to extract information about the

waves. Interferometry is an important investigative technique in the fields

of astronomy, fiber optics, engineering metrology, optical metrology,

oceanography, seismology, spectroscopy (and its applications to chemistry),

quantum mechanics, nuclear and particle physics, plasma physics, remote

sensing, biomolecular interactions, surface profiling, microfluidics,

mechanical stress/strain measurement, and velocimetry.

Laser microscopy is a rapidly growing field that uses laser illumination sources

in various forms of microscopy. For instance, laser microscopy focused on

biological applications uses ultrashort pulse lasers, in a number of

techniques labeled as nonlinear microscopy, saturation microscopy, and

multiphoton fluorescence microscopy

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Light sheet fluorescence microscopy (LSFM) is a fluorescence microscopy

technique with an intermediate optical resolution, but good sectioning

capabilities. In contrast to epifluorescence microscopy only a thin slice

(usually a few hundred nanometers to a few micrometers) of the sample is

illuminated perpendicularly to the direction of observation. For illumination

a laser lightsheet is used, i.e. a laserbeam which is focused only in one

direction (e.g. using a cylindrical lens). A second method uses a circular

beam scanned in one direction to create the lightsheet. As only the actually

observed section is illuminated, this method reduces the photodamage and

stress induced on a living sample. Also the good sectioning capability

reduces the background signal and thus creates images with higher contrast,

comparable to confocal microscopy.

Live-Cell Imaging Techniques. Live cell imaging is the study of living cells

using time-lapse microscopy. It is used by scientists to obtain a better

understanding of biological function through the study of cellular dynamics.

Live cell imaging was pioneered in first decade of the 20th century. One of

the first time-lapse microcinematographic films of cells ever made was

made by Julius Ries, showing the fertilization and development of the sea

urchin egg Since then, several microscopy methods have been developed

which allow researchers to study living cells in greater detail with less

effort. A newer type of imaging utilizing quantum dots have been used as

they are shown to be more stable.

Magnetic induction tomography. An imaging technique used to image

electromagnetic properties of an object by using the eddy current effect. It is

also called electromagnetic induction tomography, electromagnetic

tomography (EMT), eddy current tomography, and eddy current testing.

Magnetic resonance imaging (MRI) nuclear magnetic resonance imaging

(NMRI), or magnetic resonance tomography (MRT). A medical imaging

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technique used in radiology to investigate the anatomy and physiology of

the body in both health and disease. MRI scanners use strong magnetic

fields and radiowaves to form images of the body. The technique is widely

used in hospitals for medical diagnosis, staging of disease and for follow-up

without exposure to ionizing radiation. See also Functional MRI (fMRI).

Mammography is the process of using low-energy X-rays (usually around 30

Kvp) to examine the human breast and is used as a diagnostic and a

screening tool. Digital mammography is a specialized form of

mammography that uses digital receptors and computers instead of x-ray

film to help examine breast tissue for breast cancer. The electrical signals

can be read on computer screens, permitting more manipulation of images

to theoretically allow radiologists to more clearly view the results. Digital

mammography may be "spot view", for breast biopsy, or "full field"

(FFDM) for screening. Digital mammography is also utilized in stereotactic

biopsy. Breast biopsy may also be performed using a different modality,

such as ultrasound or magnetic resonance imaging (MRI)..

Medical imaging, creating images of the human body or parts of it, to diagnose

or examine disease..

Microdensitometry. A microdensitometer is an optical instrument used to

measure optical densities in the microscopic domain. A well-known

microdensitometer, used in the photographic industry, is a granularity

instrument or granularity machine. The granularity measurement involves

the use of an optical aperture, 10-50 micrometers in diameter, and in the

recording of thousands of optical density readings. The standard deviation

of this series of measurements is known as the granularity of the measured

transmission surface, optical film, or photographic film, in particular.

Micrography. A micrograph, or photomicrograph, is a photograph or digital

image taken through a microscope or similar device to show a magnified

image of an item. This is opposed to a macrographic image, which is at a

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scale that is visible to the naked eye. Micrography is also the art of using

microscopes to make photographs. 'Micrograph' is an image obtained by

means of a microscope and contains extensive details that form the features

of a microstructure. "Etching" is done to improve contrast between phases

by selective attack of some phases using reagents. Optical microscope and

electron microscope are extensively used in micrography or metallography

and are indispensable. A wealth of information can be obtained from a

simple micrograph like behavior of the material under different conditions,

the phases found in the system, failure analysis, grain size estimation,

elemental analysis and so on.

Microscopy is the technical field of using microscopes to view samples and

objects that cannot be seen with the unaided eye (objects that are not within

the resolution range of the normal eye). There are three well-known

branches of microscopy: optical, electron, and scanning probe microscopy.

For a summary of optical-microscopy techniques, see the Optical

Microscopy tutorial from Olympus. See also Specialized Microscopy

Techniques.

Molecular imaging. These techniques originated from the field of

radiopharmacology due to the need to better understand fundamental

molecular pathways inside organisms in a noninvasive manner. It enables

the visualisation of the cellular function and the follow-up of the molecular

process in living organisms without perturbing them.

Multiphoton fluorescence microscopy (MFM) uses a specialized optical

microscope. The MFM uses pulsed long-wavelength light to excite

fluorophores within the specimen being observed. The fluorophore absorbs

the energy from two long-wavelength photons which must arrive

simultaneously in order to excite an electron into a higher energy state,

from which it can decay, emitting a fluorescence signal. It differs from

traditional fluorescence microscopy in which the excitation wavelength is

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shorter than the emission wavelength, as the summed energies of two long-

wavelength exciting photons will produce an emission wavelength shorter

than the excitation wavelength.

Multispectral imaging. A multispectral image is one that captures image data at

specific frequencies across the electromagnetic spectrum. The wavelengths

may be separated by filters or by the use of instruments that are sensitive to

particular wavelengths, including light from frequencies beyond the visible

light range, such as infrared. Spectral imaging can allow extraction of

additional information the human eye fails to capture with its receptors for

red, green and blue. It was originally developed for space-based imaging.

Myelography is a type of radiographic examination that uses a contrast medium

to detect pathology of the spinal cord, including the location of a spinal

cord injury, cysts, and tumors. The procedure often involves injection of

contrast medium into the cervical or lumbar spine, followed by several X-

ray projections. A myelogram may help to find the cause of pain not found

by an MRI or CT. Myelography has been largely replaced by the use of CT

and MRI scans.

Near-field scanning optical microscopy (NSOM/SNOM) is a microscopy

technique for nanostructure investigation that breaks the far field resolution

limit by exploiting the properties of evanescent waves. This is done by

placing the detector very close (distance much smaller than wavelength λ)

to the specimen surface.

Neuroimaging or brain imaging, includes the use of various techniques to either

directly or indirectly image the structure, function/pharmacology of the

brain. It is a relatively new discipline within medicine and

neuroscience/psychology. Physicians who specialize in the performance and

interpretation of neuroimaging in the clinical setting are neuroradiologists.

Neuroimaging has also been used as non-diagnostic imaging technique, in

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experimental circumstances to allow people (especially disabled persons) to

control outside devices, acting as a brain computer interface (BCI).

Nuclear imaging. A medical specialty involving the application of radioactive

substances in the diagnosis and treatment of disease. In nuclear medicine

procedures, radionuclides are combined with other elements to form

chemical compounds, or else combined with existing pharmaceutical

compounds, to form radiopharmaceuticals. These radiopharmaceuticals,

once administered to the patient, can localize to specific organs or cellular

receptors. This property of radiopharmaceuticals allows nuclear medicine

the ability to image the extent of a disease process in the body, based on the

cellular function and physiology, rather than relying on physical changes in

the tissue anatomy. In some diseases, nuclear medicine studies can identify

medical problems at an earlier stage than other diagnostic tests. Nuclear

medicine, in a sense, is "radiology done inside out", or "endo-radiology",

because it records radiation emitting from within the body rather than

radiation that is generated by external sources like X-rays.

Optical coherence tomography (OCT) is an optical signal acquisition and

processing method. It captures micrometer-resolution, three-dimensional

images from within optical scattering media (e.g., biological tissue). Optical

coherence tomography is an interferometric technique, typically employing

near-infrared light. The use of relatively long wavelength light allows it to

penetrate into the scattering medium. Confocal microscopy, another optical

technique, typically penetrates less deeply into the sample but with higher

resolution.

Optical imaging; Optics usually describes the behavior of visible, ultraviolet,

and infrared light used in imaging. Because light is an electromagnetic

wave, similar phenomena occur in X-rays, microwaves, radio waves.

Optical imaging also comprises microscopy and other imaging techniques

using endoscopy, boroscopy, projected light and image patterns, etc.

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Optoacoustic imaging (Photoacoustic Imaging) is an imaging technology based

on the photoacoustic effect, and can be used for obtaining images of

structures in turbid environments. The optoacoustic technique combines the

accuracy of spectroscopy with the depth resolution of ultrasound.

PACS. A picture archiving and communication system is a medical imaging

technology which provides economical storage of and convenient access to,

images from multiple modalities (source machine types). Electronic images

and reports are transmitted digitally via PACS; this eliminates the need to

manually file, retrieve, or transport film jackets. The universal format for

PACS image storage and transfer is DICOM (Digital Imaging and

Communications in Medicine).

Personal imaging, real-time sharing of personal experience through images. By

2025 the POV (at least visual and auditive, but may include all senses) of

one person will be recorded, "played" and shared to others. It would be

edited, combined with other POVs, or even synthetized for Mixed Reality

experiences.

Photothermal microspectroscopy (PTMS), alternatively known as photothermal

temperature fluctuation (PTTF), is derived from two parent instrumental

techniques: infrared spectroscopy and atomic force microscopy (AFM). In

one particular type of AFM, known as scanning thermal microscopy

(SThM), the imaging probe is a sub-miniature temperature sensor, which

may be a thermocouple or a resistance thermometer. This same type of

detector is employed in a PTMS instrument, enabling it to provide

AFM/SThM images: However, the chief additional use of PTMS is to yield

infrared spectra from sample regions below a micrometer, as outlined

below.

Phase-contrast imaging is a method of imaging that has a range of different

applications. It exploits differences in the refractive index of different

materials to differentiate between structures under analysis. In conventional

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light microscopy, phase contrast can be employed to distinguish between

structures of similar transparency, and to examine crystals on the basis of

their double refraction. This has uses in biological, medical and geological

science. In X-ray tomography, the same physical principles can be used to

increase image contrast by highlighting small details of differing refractive

index within structures that are otherwise uniform. In transmission electron

microscopy (TEM), phase contrast enables very high resolution (HR)

imaging (at resolutions below one ångström), making it possible to

distinguish individual atoms from each other by their different refractive

indices.

Phase contrast microscopy is an optical microscopy technique that converts

phase shifts in light passing through a transparent specimen to brightness

changes in the image. Phase shifts themselves are invisible, but become

visible when shown as brightness variations.

Phase-contrast X-ray imaging (PCI) or phase-sensitive X-ray imaging is a

general term for different technical methods that use information

concerning changes in the phase of an X-ray beam that passes through an

object in order to create its images. Standard X-ray imaging techniques like

radiography or computed tomography (CT) rely on a decrease of the X-ray

beam's intensity (attenuation) when traversing the sample, which can be

measured directly with the assistance of an X-ray detector. In PCI however,

the beam's phase shift caused by the sample is not measured directly, but is

transformed into variations in intensity, which then can be recorded by the

detector.

Pneumoencephalography (sometimes abbreviated PEG; also referred to as an

"air study") was a common medical procedure in which most of the

cerebrospinal fluid (CSF) was drained from around the brain by means of a

lumbar puncture and replaced with air, oxygen, or helium to allow the

structure of the brain to show up more clearly on an X-ray image. It was

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derived from ventriculography, an earlier and more primitive method where

the air is injected through holes drilled in the skull.

Positron emission tomography (PET). A nuclear medicine, functional imaging

technique that produces a three-dimensional image of functional processes

in the body. The system detects pairs of gamma rays emitted indirectly by a

positron-emitting radionuclide (tracer), which is introduced into the body

on a biologically active molecule. Three-dimensional images of tracer

concentration within the body are then constructed by computer analysis. In

modern PET-CT scanners, three dimensional imaging is often accomplished

with the aid of a CT X-ray scan performed on the patient during the same

session, in the same machine.

Positron emission tomography–computed tomography (better known as PET-

CT or PET/CT) - is a medical imaging technique using a device which

combines in a single gantry system both a positron emission tomography

(PET) scanner and an x-ray computed tomography (CT) scanner, so that

images acquired from both devices can be taken sequentially, in the same

session, and combined into a single superposed (co-registered) image. Thus,

functional imaging obtained by PET, which depicts the spatial distribution

of metabolic or biochemical activity in the body can be more precisely

aligned or correlated with anatomic imaging obtained by CT scanning..

Photoacoustic imaging. A recently developed hybrid biomedical imaging

modality based on the photoacoustic effect. It combines the advantages of

optical absorption contrast with ultrasonic spatial resolution for deep

imaging in (optical) diffusive or quasi-diffusive regime.

Photoacustic imaging. A method of image reconstruction using photo-acustical

phenomena and sensors. As a hybrid biomedical imaging modality, is

developed based on the photoacoustic effect. In photoacoustic imaging,

non-ionizing laser pulses are delivered into biological tissues (when radio

Instrumentación & Señales 2014 - Jorge Márquez Flores UNAM 24

frequency pulses are used, the technology is referred to as thermoacoustic

imaging).

Photoacoustic microscopy (PAM) is a hybrid in vivo imaging technique that

acoustically detects optical contrast via the photoacoustic effect. Unlike

pure optical microscopic techniques, PAM takes advantage of the weak

acoustic scattering in tissue and thus breaks through the optical diffusion

limit (~1 mm in soft tissue). With its excellent scalability, PAM can provide

high-resolution images at desired maximum imaging depths up to a few

millimeters.

Photoacoustic tomography (PAT), or Photoacoustic computed tomography

(PACT) is a materials analysis technique based on the reconstruction of an

internal photoacoustic source distribution from measurements acquired by

scanning ultrasound detectors over a surface that encloses the source under

study.

Photoemission Electron Microscopy (PEEM, also called photoelectron

microscopy, PEM) is a widely used type of emission microscopy. PEEM

utilizes local variations in electron emission to generate image contrast

Polarized Light Microscopy. can mean any of a number of optical microscopy

techniques involving polarized light. Simple techniques include

illumination of the sample with polarized light. Directly transmitted light

can, optionally, be blocked with a polariser orientated at 90 degrees to the

illumination. More complex microscopy techniques which take advantage

of polarized light include differential interference contrast microscopy and

interference reflection microscopy. These illumination techniques are most

commonly used on birefringent samples where the polarized light interacts

strongly with the sample and so generating contrast with the background.

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Photography, the process of creating still images. Large negatives have been

used traditionally by clinicians, radiologists and physicians, using a back-lit

negatoscope.

Positron emission tomography. A nuclear medicine, functional imaging

technique that produces a three-dimensional image of functional processes

in the body. The system detects pairs of gamma rays emitted indirectly by a

positron-emitting radionuclide (tracer), which is introduced into the body

on a biologically active molecule. Three-dimensional images of tracer

concentration within the body are then constructed by computer analysis. In

modern PET-CT scanners, three dimensional imaging is often accomplished

with the aid of a CT X-ray scan performed on the patient during the same

session, in the same machine.

Quantitative phase contrast microscopy is the collective name for a group of

microscopy methods that quantify the phase shift that occurs when light

waves pass through a more optically dense object.

Radar imaging, or imaging radar, for obtaining an image of an object, not just

its location and speed.

Radiography is the use of ionizing electromagnetic radiation such as X-rays to

view objects. Although not technically radiographic techniques, imaging

modalities such as PET and MRI are sometimes grouped in radiography

because the radiology department of hospitals handle all forms of imaging.

Treatment using radiation is known as radiotherapy.

Radiology. All techniques that use photographic film to record X-ray or other

ionizing radiations to see thru low dense structures, to reveal irregulairties

in density. Medical Radiology is a medical specialty that employs the use of

imaging to both diagnose and treat disease visualized within the body.

Radiologists use an array of imaging technologies such as X-ray

radiography, ultrasound, computed tomography (CT), nuclear medicine,

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positron emission tomography (PET) and magnetic resonance imaging

(MRI) to diagnose or treat diseases. Interventional radiology is the

performance of (usually minimally invasive) medical procedures with the

guidance of imaging technologies.

Radionuclide ventriculography. A type of cardiac ventriculography, is a form of

nuclear imaging, where a gamma camera is used to create an image

following injection of radioactive material, usually Technetium-99m

(99m

Tc) labeled red blood cells. In radionuclide ventriculography, the

radionuclide has the property of circulating through the cardiac chambers,

availing for studies of the pumping function of the heart. In contrast, in

myocardial perfusion imaging, the radionuclide is taken up by the

myocardial cells, making its presence correlating with myocardial perfusion

or viability of the cells.

Range imaging, distance recording point-per-point from the sensor to the

(visible) surface of a 3D object.

Remote Sensing. Satellite multispectral images, mainly. Techniques such as

Synthetic Aperture Radar gives 3D geographical information.

Reprography, reproduction of graphics through electrical and mechanical means.

Scanning acoustic microscopy. A scanning acoustic microscope (SAM) is a

device which uses focused sound to investigate, measure, or image an

object (a process called scanning acoustic tomography). It is commonly

used in failure analysis and non-destructive evaluation. It also has

applications in biological and medical research. The semiconductor industry

has found the SAM useful in detecting voids, cracks, and delaminations

within microelectronic packages.

Scanning confocal electron microscopy (SCEM) is an electron microscopy

technique analogous to scanning confocal optical microscopy (SCOM). In

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this technique, the studied sample is illuminated by a focussed electron

beam, as in other scanning microscopy techniques, such as scanning

transmission electron microscopy or scanning electron microscopy.

However, in SCEM, the collection optics is arranged symmetrically to the

illumination optics to gather only the electrons that pass the beam focus.

Scanning electron microscope (SEM). This technique employs a type of

electron microscope that produces images of a sample by scanning it with a

focused beam of electrons. The electrons interact with atoms in the sample,

producing various signals that can be detected and that contain information

about the sample's surface topography and composition.

Scanning Joule Expansion Microscopy is a form of scanning probe microscopy

heavily based on atomic force microscopy that maps the temperature

distribution along a surface. Resolutions down to 10 nm have been achieved

and 1 nm resolution is theoretically possible. Thermal measurements at the

nanometer scale are of both academic and industrial interest, particularly in

regards to nanomaterials and modern integrated circuits.

Scanning laser ophthalmoscopy (SLO) is a method of examination of the eye. It

uses the technique of confocal laser scanning microscopy for diagnostic

imaging of retina or cornea of the human eye.

Scanning probe microscopy (SPM) is a branch of microscopy that forms images

of surfaces using a physical probe that scans the specimen. SPM was

founded with the invention of the scanning tunneling microscope in 1981.

Many scanning probe microscopes can image several interactions

simultaneously. The manner of using these interactions to obtain an image

is generally called a mode. A list of established types of Scanning probe

microscopy is found here.

Scanning thermal microscopy (SThM) is a type of scanning probe microscopy

that maps the local temperature and thermal conductivity of an interface.

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The probe in a scanning thermal microscope is sensitive to local

temperatures - providing a nanoscale thermometer. Thermal measurements

at the nanometer scale are of both scientific and industrial interest.

Scanning tunneling microscopy. A scanning tunneling microscope (STM) is

an instrument for imaging surfaces at the atomic level. Its development in

1981 earned its inventors, Gerd Binnig and Heinrich Rohrer (at IBM

Zürich), the Nobel Prize in Physics in 1986. For an STM, good resolution is

considered to be 0.1 nm lateral resolution and 0.01 nm depth resolution.

With this resolution, individual atoms within materials are routinely imaged

and manipulated. The STM can be used not only in ultra-high vacuum but

also in air, water, and various other liquid or gas ambients, and at

temperatures ranging from near zero kelvin to a few hundred degrees

Celsius.

Scintigraphy. a form of diagnostic test used in nuclear medicine, wherein

radioisotopes (here called radiopharmaceuticals) are taken internally, and

the emitted radiation is captured by external detectors (gamma cameras) to

form two-dimensional images.

Second-harmonic imaging microscopy (SHIM) is based on a nonlinear optical

effect known as second-harmonic generation (SHG). SHIM has been

established as a viable microscope imaging contrast mechanism for

visualization of cell and tissue structure and function. A second-harmonic

microscope obtains contrasts from variations in a specimen’s ability to

generate second-harmonic light from the incident light while a conventional

optical microscope obtains its contrast by detecting variations in optical

density, path length, or refractive index of the specimen.

Serial time-encoded amplified imaging/microscopy (STEAM) is a fast real-time

optical imaging method that provides MHz frame rate, ~100 ps shutter

speed, and ~30 dB (× 1000) optical image gain. An example of time-stretch

microscopy, STEAM holds world records for shutter speed and frame rate

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in continuous real-time imaging. STEAM employs the photonic time stretch

along with optical image amplification to circumvent the fundamental

trade-off between sensitivity and speed that affects virtually all optical

imaging and sensing systems. This method employs a single-pixel

photodetector, eliminating the need for the detector array and readout time

limitations. Avoiding this problem and featuring the optical image

amplification for dramatic improvement in sensitivity at high image

acquisition rates, STEAM's shutter speed is at least 1000 times faster than

the state-of-the-art CCD and CMOS cameras. Its frame rate is 1000 times

faster than fastest CCD cameras and 10-100 times faster than fastest CMOS

cameras.

Single photon emission computed tomography (SPECT, or less commonly,

SPET) is a nuclear medicine tomographic imaging technique using gamma

rays. It is very similar to conventional nuclear medicine planar imaging

using a gamma camera.

Spectral imaging is a branch of spectroscopy and of photography in which a

complete spectrum or some spectral information (such as the Doppler shift

or Zeeman splitting of a spectral line) is collected at every location in an

image plane. Applications include astronomy, solar physics, planetology,

and Earth remote sensing.

Speckle imaging, a method of shift-and-add for astronomical imaging. Othe

describes a range of high-resolution astronomical imaging techniques based

either on the shift-and-add ("image stacking") method or on speckle

interferometry methods.

Spiral computed tomography is a computed tomography technology involving

movement in a helical pattern for the purpose of increasing resolution. Most

modern hospitals currently use spiral CT scanners.

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Stereo imaging, is an aspect of sound recording and reproduction concerning

spatial locations of the performers. For three-dimensional visual imaging,

see stereoscopy.

Stereomicroscopy. The stereo or stereoscopic or dissecting microscope is an

optical microscope variant designed for low magnification observation of a

sample, typically using light reflected from the surface of an object rather

than transmitted through it. The instrument uses two separate optical paths

with two objectives and eyepieces to provide slightly different viewing

angles to the left and right eyes. This arrangement produces a three-

dimensional visualization of the sample being examined. Stereomicroscopy

overlaps macrophotography for recording and examining solid samples

with complex surface topography, where a three-dimensional view is

needed for analysing the detail.

Stereo Vision (or Stereopsis). perception of depth and 3-dimensional structure

obtained on the basis of visual information deriving from two eyes by

individuals with normally developed binocular vision. In stead of animal or

human eyes, two cameras may also give the information required for

Stereoscopy. a technique for creating or enhancing the illusion of depth in an

image by means of stereopsis for binocular vision. Any stereoscopic image

is called stereogram. Originally, stereogram referred to a pair of stereo

images which could be viewed using a stereoscope.

Stethoscope. The stethoscope is an acoustic medical device for auscultation, or

listening to the internal sounds of an animal or human body. It is often used

to listen to lung and heart sounds. It is also used to listen to intestines and

blood flow in arteries and veins. In combination with a

sphygmomanometer, it is commonly used for measurements of blood

pressure. Less commonly, "mechanic's stethoscopes" are used to listen to

internal sounds made by machines, such as diagnosing a malfunctioning

automobile engine by listening to the sounds of its internal parts.

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Stethoscopes can also be used to check scientific vacuum chambers for

leaks, and for various other small-scale acoustic monitoring tasks. A

stethoscope that intensifies auscultatory sounds is called phonendoscope.

Super-resolution microscopy is a form of light microscopy. Due to the

diffraction of light, the resolution of conventional light microscopy is

limited as stated by Ernst Abbe in 1873. A good approximation of the

resolution attainable is the FWHM (full width at half-maximum) of the

point spread function, and a precise widefield microscope with high

numerical aperture and visible light usually reaches a resolution of

~250 nm.

Synthetic aperture photography: By integrating an appropriate 4D subset of the

samples in a light field, one can approximate the view that would be

captured by a camera having a finite (i.e., non-pinhole) aperture. Such a

view has a finite depth of field. By shearing or warping the light field

before performing this integration, one can focus on different fronto-parallel

(Isaksen 2000) or oblique (Vaish 2005) planes in the scene. If the light field

is captured using a handheld camera (Ng 2005), this essentially constitutes

a digital camera whose photographs can be refocused after they are taken.

Synthetic-aperture imaging. See Aperture synthesis imaging above.

Synthetic-aperture radar (SAR) is a form of radar which is used to create

images of an object, such as a landscape. SAR uses the motion of the SAR

antenna over a target region to provide finer spatial resolution than is

possible with conventional beam-scanning radars. SAR is typically

mounted on a moving platform such as an aircraft or spacecraft, and it

originated as an advanced form of side-looking airborne radar (SLAR). The

distance the SAR device travels over a target creates a large "synthetic"

antenna aperture (the "size" of the antenna). As a rule of thumb one can

assume that the larger the aperture is, the higher the image resolution

becomes, regardless whether phys ical aperture or synthetic aperture – this

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allows SAR to create high resolution images with comparatively small

physical antennas.

Synthetic aperture sonar (SAS) is a form of sonar in which sophisticated post-

processing of sonar data are used in ways closely analogous to synthetic

aperture radar. Synthetic aperture sonars combine a number of acoustic

pings to form an image with much higher resolution than conventional

sonars, typically 10 times higher. The principle of synthetic aperture sonar

is to move a sonar along a line and illuminate the same spot on the sea floor

with several pings. This produces a synthetic array equal to the distance

traveled. By coherent reorganization of the data from all the pings, a

synthetic aperture image is produced with improved along-track resolution.

In contrast to conventional side-scan sonar, SAS processing provides range-

independent along-track resolution. At maximum range the resolution can

be magnitudes better than that of side-scan sonars.

Tactile imaging is a medical imaging modality that translates the sense of touch

into a digital image. The tactile image is a function of P(x,y,z), where P is

the pressure on soft tissue surface under applied deformation and x,y,z are

coordinates where pressure P was measured

Thermography, infrared thermography (IRT) and termal video are examples of

infrared imaging science. At present, it is used basically for the breast

imaging. A thermographic camera (also called an infrared camera or

thermal imaging camera) is a device that forms an image using infrared

radiation, similar to a common camera that forms an image using visible

light. Instead of the 450–750 nanometer range of the visible light camera,

infrared cameras operate in wavelengths as long as 14,000 nm (14 µm).

Thrombelastography (TEG) is a method of testing the efficiency of blood

coagulation. It is a test mainly utilized in surgery and anesthesiology,

although few centers are capable of performing it. More common tests of

blood coagulation include prothrombin time (PT,INR) and partial

Instrumentación & Señales 2014 - Jorge Márquez Flores UNAM 33

thromboplastin time (aPTT) which measure coagulation factor function, but

TEG also can assess platelet function, clot strength, and fibrinolysis which

these other tests cannot. Thromboelastometry (TEM), previously named

rotational thromboelastography (ROTEG) or rotational

thromboelastometry (ROTEM), is another version of TEG in which it is the

sensor shaft, rather than the cup, that rotates.

Thromboelastometry (TEM), previously named rotational

thromboelastography (ROTEG) or rotational thromboelastometry

(ROTEM), is an established viscoelastic method for hemostasis testing in

whole blood. It is modification of traditional thromboelastography (TEG).

TEM investigates the interaction of coagulation factors, their inhibitors,

anticoagulant drugs, blood cells, specifically platelets, during clotting and

subsequent fibrinolysis. The rheological conditions mimic the sluggish flow

of blood in veins. TEM is performed with the ROTEM whole blood

analyzer (Tem Innovations GmbH, Munich) and is an enhancement of

thrombelastography, originally described by H. Hartert in 1948.

Transmission electron microscopy (TEM) is a microscopy technique in which a

beam of electrons is transmitted through an ultra-thin specimen, interacting

with the specimen as it passes through.

Time-lapse microscopy is time-lapse photography applied to microscopy.

Microscope image sequences are recorded and then viewed at a greater

speed to give an accelerated view of the microscopic process. Before the

introduction of the video tape recorder in the 1960s, time-lapse microscopy

recordings where made on photographic film. During this period, time-lapse

microscopy was referred to as microcinematography. With the increasing

use of video recorders, the term time-lapse video microscopy was gradually

adopted. Today, the term video is increasingly dropped, reflecting that a

digital still camera is used to record the individual image frames, instead of

a video recorder.

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Tomography is the method of imaging a single plane, or slice, of an object

resulting in a tomogram. There are several forms of tomography: Linear

tomography, Poly tomography, Zonography, Orthopantomography,

Computed Tomography, Magnetic induction tomography and Positron

emission tomography.

Total internal reflection fluorescence microscopy (TIRF Microscopy). A total

internal reflection fluorescence microscope (TIRFM) is a type of

microscope with which a thin region of a specimen, usually less than

200 nm can be observed.

Two-photon excitation microscopy is a fluorescence imaging technique that

allows imaging of living tissue up to a very high depth, up to about one

millimeter. Being a special variant of the multiphoton fluorescence

microscope, it uses red-shifted excitation light which can also excite

fluorescent dyes. However, for each excitation, two photons of infrared

light are absorbed. Using infrared light minimizes scattering in the tissue.

Due to the multiphoton absorption, the background signal is strongly

suppressed. Both effects lead to an increased penetration depth for these

microscopes. Two-photon excitation can be a superior alternative to

confocal microscopy due to its deeper tissue penetration, efficient light

detection, and reduced phototoxicity.

Ultrasonic Force Microscopy (UFM) has been developed in order to improve

the details and image contrast on "flat" areas of interest where the atomic

force microscopy (AFM) images are limited in contrast. The combination of

AFM-UFM allows a near field acoustic microscopic image to be generated.

The AFM tip is used to detect the ultrasonic waves and overcomes the

limitation of wavelength that occurs in acoustic microscopy. By using the

elastic changes under the AFM tip, an image of much greater detail than the

AFM topography can be generated.

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(Medical) ultrasonography, an ultrasound-based diagnostic imaging technique.

With consistent technological improvements, this modality is now used

throughout the body for imaging almost every soft tissue area, in particular

interfaces and cavities.

Ultraviolet microscopy. Ultraviolet microscopes have two main purposes. The

first is to utilize the shorter wavelength of ultraviolet electromagnetic

energy to improve the image resolution beyond that of the diffraction limit

of standard optical microscopes. This technique is used for non-destructive

inspection of devices with very small features such as those found in

modern semiconductors. The second application for UV microscopes is

contrast enhancement where the response of individual samples is

enhanced, relative to their surrounding, due to the interaction of light with

the molecules within the sample itself. One example is in the growth of

protein crystals. Protein crystals are formed in salt solutions. As salt and

protein crystals are both formed in the growth process, and both are

commonly transparent to the human eye, they cannot be differentiated with

a standard optical microscope.

USB microscopy. A USB microscope is a low-powered digital microscope

which connects to a computer, normally via a USB port. They are widely

available at low cost commercially. In essence USB microscopes are a

webcam with a high-powered macro lens and generally do not use

transmitted light, but rely on incident light from in-built LEDs lights

situated next to the lens. The light reflected from the sample then enter the

camera lens.

Video. Motion image recording as an electronic raster signal (kind of "inverse

TV"). Video is also the electronic medium for the recording, copying and

broadcasting of moving visual images.

Virtual microscopy is a method of posting microscope images on, and

transmitting them over, computer networks. This allows independent

Instrumentación & Señales 2014 - Jorge Márquez Flores UNAM 36

viewing of images by large numbers of people in diverse locations. It

involves a synthesis of microscopy technologies and digital technologies.

The use of virtual microscopes can transform traditional teaching methods

by removing the reliance on physical space, equipment, and specimens to a

model that is solely dependent upon computer-internet access. This

increases the convenience of accessing the slide sets and making the slides

available to a broader audience. Digitized slides can have a high resolution

and are resistant to being damaged or broken over time.

Whole Body Imaging. (WBI) refers to the internal display of the entire body in a

single procedure. It also refersto Backscatter low-level X-ray devices

employed in airports and customs for inspecting and security purposes.

Other WB techniques are the Millimeter wave scanner, WBI Backscatter X-

ray and Infra-red thermal difference detection. In medical imaging, it may

also refer to full-body CT scan or magnetic resonance imaging.

X-ray computed tomography (X-ray CT) is a technology that uses computer-

processed x-rays to produce tomographic images (virtual 'slices') of specific

areas of the scanned object, allowing the user to see what is inside it

without cutting it open. Digital geometry processing is used to generate a

three-dimensional image of the inside of an object from a large series of

two-dimensional radiographic images taken around a single axis of rotation.

Medical imaging is the most common application of x-ray CT. Its cross-

sectional images are used for diagnostic and therapeutic purposes in various

medical disciplines. The rest of this article discusses medical-imaging x-ray

CT; industrial applications of x-ray CT are discussed at industrial computed

tomography scanning.

X-ray fluorescence (XRF) is the emission of characteristic "secondary" (or

fluorescent) X-rays from a material that has been excited by bombarding

with high-energy X-rays or gamma rays. The phenomenon is widely used

for elemental analysis and chemical analysis, particularly in the

Instrumentación & Señales 2014 - Jorge Márquez Flores UNAM 37

investigation of metals, glass, ceramics and building materials, and for

research in geochemistry, forensic science and archaeology.

X-ray microtomography, like tomography and x-ray computed tomography, uses

x-rays to create cross-sections of a physical object that can be used to

recreate a virtual model (3D model) without destroying the original object.

The prefix micro- (symbol: µ) is used to indicate that the pixel sizes of the

cross-sections are in the micrometre range. These pixel sizes have also

resulted in the terms high-resolution x-ray tomography, micro–

computed tomography (micro-CT or µCT), and similar terms. Sometimes

the terms high-resolution CT (HRCT) and micro-CT are differentiated, but

in other cases the term high-resolution micro-CT is used. Virtually all

tomography today is computed tomography.

Xerography, (or electrophotography) the method of photocopying.

Zonography. This is a variant of linear tomography, where a limited arc of

movement is used. It is still used in some centres for visualising the kidney

during an intravenous urogram (IVU).