Ultrasound image

Picot PA, Rickey DW, Mitchell R, Rankin RN, Fenster A (1993) Three-dimensional colour Doppler imaging. Ultrasound Med Biol 19 95-104... 

Nelson TR, Pretorius DH (1998) Three-dimensional ultrasound imaging. Ultrasound Med Biol 24 1243-1270 Ofili EO, Navin CN (1994) Three-dimensional and fourdimensional echocardiography. Ultrasound Med Biol 20 669-675... 

Thrush AJ, Bonnett DE, Elliott MR (1997) An evaluation of the potential and limitations of three-dimensional reconstructions from intravascular ultrasound images. Ultrasound Med Biol 23 437-445... 

An aq. soln. at 31° contains 30% a-pyr, 64% P-pyr, 2.5% a-fur, 3.5% P-fur and 0.02% aldehyde. Active ingredient of Levovist , used in echo-enhancement in sonographic Doppler-B-mode imaging. Ultrasound contrast medium. 

Nelson, T, and Pretorius, D., "Three-Dimensional Ultrasound Imaging," Ultrasound Med. Biol, 24, pp. 1243-70, 1998. 

Pediatrics has a significant impact on many medical fields laboratory medicine intensive care equipment medical imaging (ultrasound, magnetic... 

Introduction Optical Imaging Radiation-Based Imaging Ultrasound Infrared Imciging Nuclear Magnetic Resonance Conclusion Acknowledgments References... 

Foster F, Mehi J, Lukacs M et al (2009) A new 15-50 MHz based micro-ultrasound scanner for preclinical imaging. Ultrasound Med Biol 35 1700-1708. 

The weld depths penetration for gold-nickel alloy and tantalum cylinders have been well controlled by an entirely contactless ultrasound method. Nevertheless, the development of signal and image processing will allow to increase the resolution of the ultrasonic images. Moreover, in order to be able to size quite well the lacks of weld penetration, the simulation of the interaction beam-defect is presently developed in our laboratory. 

The source and detector of ultrasound in an ultrasound medical imager is called a transducer. The transducer is a piezoelectric crystal which physically changes its dimensions when a potential is appHed across the crystal (38). The appHcation of a force to the piezoelectric crystal which changes its dimensions creates a voltage in the crystal. AppHcation of an oscillating potential to the crystal causes the dimensions of the crystal to oscillate and hence create a sound at the frequency of the oscillation. The appHcation of an oscillating force to the crystal creates an alternating potential in the crystal. 

The transducers on most ultrasound imaging systems operate at a frequency between 1 and 20 MH2. The attenuation, of ultrasound by tissues is both frequency and tissue dependent. The attenuation coefficient, a, of a tissue is defined by equation 5 ... 

The resolution in an ultrasound image is, among other things, related to the duration of the ultrasound pulse, ie, the shorter the pulse the better the resolution. Imaging may not be performed when the pulse duration is longer than the time to receive an echo. The shorter the ultrasound pulse the more difficult it is to discern it from noise, and the poorer the SNR of the image. As the pulse duration is decreased, the power of the ultrasound pulse is typically increased to compensate for the poorer SNR. 

Special small ultrasound transducers, often referred to as endoscopic transducers, have been designed which can be inserted into blood vessels to examine blockages in arteries (43). These transducers operate at approximately 20 MHz and have a viewing distance of less than a centimeter. Such devices are capable of producing ultrasound images of the inside of arteries and veins. The quaUty of the ultrasound image is sufficient to determine the type of blockage. 

---