| through transfer imaging | The production of an ultrasound image by detection and analysis of sound on the opposite side of the body from the emitting transducer. Synonym: through transfer imaging. (05 Mar 2000) |
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| thyroid imaging | <radiology> Tc-99m pertechnetate 6 mCi, I-123 sodium iodide 200 - 400 uCi PO (12 Dec 1998) |
| transfer imaging | The production of an ultrasound image by detection and analysis of sound on the opposite side of the body from the emitting transducer. Synonym: through transfer imaging. (05 Mar 2000) |
| ultrasound imaging | <investigation, procedure> A technique in which high-frequency sound waves are bounced off internal organs and the echo pattern is converted into a 2 dimensional picture of the structures beneath the transducer. (12 May 1997) |
| kidney: gallium imaging | <radiology> 10-20% of Ga-67 excreted via GU tract; no renal activity after 24hrs abnormal uptake (images at 48-72 hrs): tumour, primary renal tumour (variable uptake), lymphoma/leukaemia, metastases (e.g., melanoma), inflammation, acute pyelonephritis (88% sensitivity); abscess, lobar nephroma, others, collagen vascular disease, vasculitis, Wegener granulomatosis, amyloidosis, haemochromatosis, hepatic failure, antineoplastic drugs, transplant rejection: acute, chronic, ATN see also: gallium: indications (12 Dec 1998) |
| liver metastases: ultrasound imaging | <radiology> Echogenic (25%), colonic carcinoma, hepatocellular carcinoma, treated breast carcinoma mixed echogenicity (37.5%), breast carcinoma, rectal carcinoma, lung carcinoma, stomach carcinoma, anaplastic cancer, cervical carcinoma, carcinoid hypoechoic (37.5%), lymphoma, pancreatic carcinoma, cervical carcinoma, lung carcinoma (adenocarcinoma), nasopharyngeal carcinoma see: liver metastases (12 Dec 1998) |
| lung: gallium imaging | <radiology> Scans at 48 hrs because 50% of normals show activity at 24 hrs, focal uptake, primary pulmonary malignancy, benign disorder: granuloma, abscess, pneumonia, silicosis, multifocal/diffuse uptake, infection, TB: active lesion, miliary TB, rapidly progressive TB pneumonia, PCP: unimpressive symptoms and CXR, CMV, inflammation: sarcoid, interstitial lung disease (pneumoconiosis, idiopathic pulmonary fibrosis, lymphangitic carcinomatosis), radiation pneumonitis, drugs: bleomycin, amiodarone, contrast lymphangiography (in 50%) see: gallium: indications, uptake with normal chest film (12 Dec 1998) |
| aperture for electron microscopy | <technique> Anode aperture: The opening in the accelerating voltage anode shield of the electron gun through which the electrons must pass to irradiate the specimen. Condenser aperture: An opening in the condenser lens controlling the number of electrons entering the lens and the angular aperture of the electron beam. The angular aperture can also be controlled by the condenser lens current. Physical objective aperture: A metallic diaphragm, with a small central hole, used to limit the cone of electrons accepted by the objective lens. This improves image-contrast since highly scattered electrons are prevented from arriving at the Gaussian image plane and therefore cannot contribute to background fog. Aplanatic. Free from spherical aberration and coma. (05 Aug 1998) |
| Auger electron | An electron ejected from a lower energy orbital after a photoelectric interaction of an X-ray photon with a K-shell electron by the characteristic radiation photon; the Auger electron recoils with energy equal to the characteristic radiation less the difference in shell binding energies. See: photoelectric effect. (05 Mar 2000) |
| valence electron | One of the electron's that take part in chemical reactions of an atom. (05 Mar 2000) |
| Parallel Electron Energy Loss Spectroscopy | <technique> Electron energy loss spectroscopy analyses the inelastically scattered electrons present in the beam after it has been transmitted through the sample. An electron energy loss spectrum typically consists of a monatomic decreasing background on which are superimposed a number of peaks. Each peak is characteristic of the scattering process that has occurred in the sample. The peaks can be used to obtain information about the chemical composition and electronic structure of the sample. Electron energy loss spectra are acquired typically in a magnetic sector spectrometer located under the camera chamber of the transmission electron microscope. Spatial resolution is typically limited by the minimum probe diameter of the microscope. Electron energy loss spectroscopy tends to be complimentary to EDS in that it can be used to analyse very thin samples of low Z materials. Acronym: PEELS (05 Aug 1998) |
| reverse electron transport | <chemistry> The energy-dependent movement of electrons against the thermodynamic gradient to form a strong reductant from a weaker electron donor. (11 Jan 1998) |
| microscope, electron | <microscopy> An electron-optical device which produces a magnified image of an object. Detail may be revealed by virtue of selective transmission, reflection, or emission of electrons by the object. (05 Aug 1998) |
| microscopy, electron | Visual and photographic microscopy in which electron beams with wavelengths thousands of times shorter than visible light are used in place of light, thereby allowing much greater magnification. (12 Dec 1998) |
| microscopy, electron, scanning | Microscopy in which the object is examined directly by an electron beam scanning the specimen point-by-point, giving the surface image a three-dimensional quality. (12 Dec 1998) |