Image Tool

Theory and Equipment. Many diseases of the human body can be identified by visual appearance. Tumors in the upper gastrointestinal (GI) tract, for example, possess a characteristic salmon pink color (3). The presence of such a color can be an indication of disease. Endoscopy is the medical imaging tool used to detect such colors in the inside of hoUow internal organs such as the rectum, urethra, urinary bladder, stomach, colon, etc. An endoscope is the instmment used to perform endoscopy. Endoscopic imaging involves the production of a tme color picture of the inside of the human body using lenses and either hoUow pipes, a fiber optic bundle, or a smaU CCD camera. AU three use a large field-of-view, sometimes referred to as a fish eye, lens to aUow a 180° field of view. 

Technetium-99m coordination compounds are used very widely as noniavasive imaging tools (35) (see Imaging technology Radioactive tracers). Different coordination species concentrate ia different organs. Several of the [Tc O(chelate)2] types have been used. In fact, the large majority of nuclear medicine scans ia the United States are of technetium-99m complexes. Moreover, chiral transition-metal complexes have been used to probe nucleic acid stmcture (see Nucleic acids). For example, the two chiral isomers of tris(1,10-phenanthroline)mthenium (IT) [24162-09-2] (14) iateract differentiy with DNA. These compounds are enantioselective and provide an addition tool for DNA stmctural iaterpretation (36). 

Covalent attachment of antibody molecules to liposomes can provide a targeting capacity to the vesicle that can modulate its binding to specific antigenic determinants on cells or to molecules in solution. Antibody-bearing liposomes may possess encapsulated components that can be used for detection or therapy (Figure 22.17). For instance, fluorescent molecules encapsulated within antibody-targeted vesicles can be used as imaging tools or in flow cytometry... 

Since its invention nearly 100 years ago, electron microscopy (EM) has developed into a remarkably versatile imaging tool. Nearly all major R D organizations (universities, national laboratories, industrial labs) have EM facilities that can accommodate well-established imaging techniques. Despite its apparent maturity, new techniques continue to be developed that not only push the resolution limits of EM but also expand the range of specimens and environments in which it can be used. 

As new imaging tools have become available, such as CT and MRI, many attempts have been made to evaluate imaging criteria for assessing the severity of acute pancreatitis. The first severity index of acute pancreatitis was developed in 1990 by Balthazar et al. (B2). The CT Scoring Index (CTSI) is a 10-point system based on the degree and the type of changes in pancreatic parenchyma and peripancreatic tissues as well as the extent of pancreatic necrosis. The majority of studies confirm its clinical utility for prediction of severity of AP (K6, LI, M20, S14, VI) however, some authors report CT to be ineffective (L13, L14). 

AFM, invented in 1986 [25], has been optimized as a surface imaging tool for a variety of materials from metals to insulators by scanning the surface with a thin metallic cantilever, with a sharp tip on the end, coming to a point with a radius on the order of 10 nm. As the tip is scanned across a surface, the tip-stage position is controlled in three dimensions by a set of oriented piezo crystals (see Figure 4.2). An optical lever comprised of a laser in conjunction with a photodiode is used to measure cantilever deflection in a closed loop feedback system (based on amount of deflection of the cantilever in the simplest mode of operation). As the tip rasters across the surface, a three-dimensional topography map of the surface is created. 

The acquisition of the mass spectra for peptide and protein imaging is done in our lab on commercial MALDI TOF instruments (Voyager sSTR, 4700 Proteomics Analyzer Applied Biosystems, Framingham, MA) equipped with a Nd YAG laser. The acquisition of the data is controlled by an in-house designed software (MALDI MS Imaging Tool, MMSIT). The area to be scanned is specified as a pattern of points, equidistant from each other. The distance is chosen referring to the diameter of the... 

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