Imaging, high frequency ultrasound

Daftari I, Braash D, Lin S and O Brian J (2001) Use of high-frequency ultrasound imaging to improve delineation of anterior uveal melanoma for proton irradiation. Phys Med Biol 46 579-590. 

Swanson, T. A., Conte, T, Deeley, B., Portugal, S., Kreeger, J. M., Obert, L. A., Joseph, E. C., Wisialowski, T. A., Sokolowski, S. A., Rief, C., Nugent, R, Lawton, M. R, and Enerson, B. E. (2014). Hemodynamic correlates of drug-induced vascular injury in the rat using high-frequency ultrasound imaging. Toxicol Pathol 42, 784. 

Lockwood, G. R., Hunt, J. W. and Foster, F. S. (1991) The Design of Protection Ciicuitiy for High-Frequency Ultrasound Imaging Systems, IEEE Transactions On Ultrasonics, Ferroelectrics and Frequency Control, 38, 48-55. 

Essentially all imaging from medical ultrasound to non-destructive testing relies upon the same pulse-echo type of approach but with considerably refined electronic hardware. The refinements enable the equipment not only to detect reflections of the sound wave from the hard, metallic surface of a submarine in water but also much more subtle changes in the media through which sound passes (e. g. those between different tissue structures in the body). It is high frequency ultrasound (in the range 2 to 10 MHz) which is used primarily in this type of application because by using these... 

The first area involves low amplitude (higher frequency) sound and is concerned with the physical effect of the medium on the wave and is commonly referred to as low power or high frequency ultrasound . Typically, low amplitude waves are used for analytical purposes to measure the velocity and absorption coefficient of the wave in a medium in the 2 to 10 MHz range. Information from such measurements can used in medical imaging, chemical analysis and the study of relaxation phenomena and this will be dealt with later. 

Denoyer A, Ossant F, Arbeille B, Fetissof F, Patat F, Pourcelot L, Pisella P-J. Very-high-frequency ultrasound comeal imaging as a new tool for early diagnosis of ocular surface toxicity in rabbits treated with a preserved glaucoma dmg. Ophthalm Res 2008 40 298-308. 

Yu J, Takanari K, Hong Y, Lee KW, Amoroso NJ, Wang Y, et al. Non-invasive characterization of polyurethane-based tissue constructs in a rat abdominal repair model using high frequency ultrasound elasticity imaging. Biomaterials April 2013 34(ll) 2701-9. 

High-frequency or diagnostic ultrasound in clinical imaging (3-10 MHz) Medium-frequency or therapeutic ultrasound in physical therapy (0.7-3.0 MHz) Low-frequency or power ultrasound for lithotripsy, cataract emulsification, liposuction, tissue ablation, cancer therapy, dental descaling, and ultrasonic scalpels (18-100 kHz)... 

Ultrasound (or sonophoresis) is a technology more traditionally associated with the fields of physiotherapy, sports medicine, and medical imaging rather than transdermal dmg delivery. Compared to physiotherapy, where high-frequency energy (1 MHz) is used, in transdermal dmg delivery low-frequency energy (20 kHz region) is applied across the skin. Cavitation, the acoustically induced formation and oscillation of gas bubbles formed because of the mechanical energy supplied, is the most probable... 

Ultrasound imaging is a non-invasive, portable and relatively inexpensive imaging modality, which is used extensively in the clinic. An ultrasound transducer (also called scanhead) sends short pulses of a high-frequency sound wave (1-10 MHz) into the body. At interfaces between two types of tissue, the wave will be refracted and part of the sound wave is reflected back due to Snells law. How much is reflected depends on the densities of the respective tissues, and thus the speed of the sound wave within the different tissues. In addition, parts of the sound wave are also backscattered from small structures at tissue boundaries or within the tissue. High-frequency sound waves propagate weU through soft tissue and fluids, but they are more or less stopped by air or bone. In clinical practice, this limitation is referred to as an acoustic window . The transducer not only sends the wave into the body but also receives part of the reflected and/or backscattered wave, also named echo . In clinical practice, ultrasound is used in a... 

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