Medical diagnostics imaging

Krestel, E., Imaging Systems for Medical Diagnostics. 1990, Berlin Siemens. 

Computerized Tomographic Imaging (CT), a well established method in medical diagnostics for 25 years now, also makes its arrival into non-destructive testing since the last decade. 

Magnetic resonance imaging, MRI (Chapter 13 Focus On) A medical diagnostic technique based on nuclear magnetic resonance. 

In the context of the development of new contrast agents for medical diagnostic imaging, the nanoparticulate carriers have indeed drawn special attention. These systems allow for an efficient site-specific delivery of targeted contrast agents and, due to their size, provide some relaxivity enhancement with respect to the isolated paramagnetic molecules. 

The helium supply seemed secure, but then scientists discovered a whole new application for the gas. Helium boils at the lowest temperature of any substance (-269°C) and it never solidifies. Liquid helium is therefore the ideal substance to cool electrical wires and reduce their resistance to the flow of the current. It has allowed us to manufacture superconducting magnets, which have diverse applications, but probably none more useful than in magnetic resonance imaging. This technology affords doctors a noninvasive look inside the human body, and it Is probably the most important medical diagnostic tool ever developed. The future of mri, however, hinges on the availability of helium. Think about that the next time you fill those birthday balloons with the gas. 

Kamerlingh Onnes, at the University of Leiden, discovered superconductivity in 1911. He found that the resistance of some metallic wires became zero at very low temperature it did not just approach zero, there was no dissipation of heat. At that time his laboratory was the only one equipped for studies at the temperature of liquid He (bp 4.1 K). Theoretical explanations of the phenomenon did not appear until the work of John Bardeen, Leon Cooper, and Robert Schrieffer in 1957. They received the Nobel Prize in Physics in 1972. The expense and difficulty of applying superconductivity to practical problems limits the applications. Nevertheless, superconductor magnets of very high field are now widely used in NMR in chemistry and the medical diagnostic applications of NMR called MRI (magnetic resonance imaging—they wanted to avoid the word "nuclear ). 

Lack of advances in optics has hampered improvements in microscopic imaging. Development of adaptable, inexpensive fiber optics to transmit high-energy femtosecond pulses from mode-locked lasers, custom phase plates, and miniature laser beam scanners for endoscopic microscopy instruments offer the potential for enormous advances in laser scanning microscopy for various applications, including medical diagnostics and surgery. 

X-ray diffraction imaging in its early days followed a similar path to target medical diagnostic applications. Several investigators found remarkable differences between the diffraction profiles of healthy and diseased tissue in the skeleton [11] and breast [12], to name just two examples. Dose considerations however, particularly compared with MRI, have prevented up to now the widespread application of XDI in diagnostic radiology. 

Fig. 6.20 (a) Piezoceramic parts for a range of applications including accelerometers, underwater acoustics, pressure and liquid level sensors, medical diagnostics and therapeutics and NDT the ultrasound focusing bowls are for medical imaging and for producing high-intensity focused ultrasound. 

Supramolecular chemistry is now at the forefront of clinical practice. By linking lanthanide metal-macrocyclic complexes to tissue selective receptors the use of magnetic resonance imaging has become far more useful and widespread. This technique, which relies on the receptor-spacer-reporter motif, has become one of the most powerful medical diagnostics tools available in hospitals worldwide. 

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