Ultrasound imaging application

I. Cespedes, J. Ophir, H. Ponnekanti and N. Maklad, Elastography elasticity imaging using ultrasound with application to muscle and breast in vivo, Ultrason. Imaging, 1993, 15, 73-88. 

The third chapter is dedicated to contrast agents for ultrasound imaging starting with the design, preparation and application of microbubbles. Additionally, the different presently available generations of contrast agents are... 

A.L. Klibanov, Microbubble contrast agents Targeted ultrasound imaging and ultra-sound-assisted drug-delivery applications. Invest. Radiol. 41 (2005) 354-362. 

Clark JM, Brancati FL, Diehl AM (2002) Nonalcoholic fatty liver disease. Gastroenterology 122 1649-1657 Coatney RW (2001) Ultrasound imaging principles and applications in rodent research. liar Journal 42 233-247 Cockman MD, Hayes DA, Kuzmak BR (1993) Motion suppression improves quantification of rat liver volume in vivo by magnetic resonance imaging. Magnetic Resonance in Medicine 30 355-360... 

A newer application of pure perfluorocarbons with relatively low boiling points is as contrast agents for medical ultrasound examination of the circulatory system [112]. Making the ultrasound imaging technique available for examination of, in particular, the cardiovascular system and other soft tissues is highly important, because ultrasound technology is far more widespread and less expensive than other imaging equipment. 

Piezoelectric transducers are key components in medical ultrasound imaging and are used both as the acoustic source and the detector (pulse-echo teclmique). The uses for ultrasound are numerous and include examination of the fetus in the mother s womb as shown in Figure 31.22 and high-resolution imaging of intravascular structures. PZT is the ceramic of choice for this application mainly because it has a high k and is inexpensive compared to some of the other options such as polymer piezoelectrics. 

The uses of dielectrics range from capacitors for storing charge to ultrasound imaging for medical applications. We separate dielectrics from insulators, which we described in Chapter 30, because dielectrics have permanent electric dipoles. If the resultant polarization is spontaneous we have ferroelectrics. This topic is essentially exclusive ceramic materials. Although some polymers are ferroelectric they do not find as wide use as ceramics. And metals cannot be ferroelectric because the charge is not localized. 

Ultrasound imaging instrumentation for example can measure many of the parameters that bioimpedance also can measure. When a medical doctor already has the ultrasound probe in his or her hand as a multiparameter measuring device, the bioimpedance technology must offer some definite advantages. The task is to select the application which is sufficiently adequate for the purpose. 

CMUT devices are used in the real-time in vivo imaging applications with an improved performance over the existing medical ultrasound transducers. A wafer-bonded CMUT probe showed a bandwidth of 130 %... 

Medical imaging applications collect data about patients bodies and turn that data into useful images that physicians can interpret for diagnostic purposes. For example, ultrasound scans, which map the reflection and reduction in force of sounds as they bounce off an object, are used to monitor the development of fetuses in the wombs of pregnant women. Magnetic resonance imaging (MRI), which measures the response of body tissues to high-frequency radio waves, is often used to detect structural abnormalities in the brain or other body parts. 

Meuwly JY, Thiran JP, Gudinchet F (2003) Application of adaptive image processing technique to real-time spatial compound ultrasound imaging improves image quality. Invest Radiol 38 257-262... 

Figure 21.7 Ultrasound image of the fully implanted artificial diaphragm device, viewed edge on. The circle shows the region of the artificial diaphragm the arrow shows the remainder of the natural diaphragm muscle. (Reprinted with permission from ASM Proceedings ofMPMD 2007, Medical Device Applications of Dielectric Elastomer-Based Artificial Muscles by Bashkin, J. S., Heim, j., Prahlad, H. et al. Copyright (2007) ASM).

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