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The stiffer the tissue, the faster will the ultrasound travel in that medium (direct relationship). 1a). Ultrasound Physics | Radiology Key It is expressed in decibels or dB, which is a logarithmic scale. For example, if we have a matrix of 128 by 128 PZT elements, one can generate over 16 thousand scan lines. The wavelength is equal to twice the thickness of the elements in the transducer. An ultrasound pulse is created by applying alternative current to these crystals for a short time period. These resolution points are all relative to the type of transducer array being used and its construction. The axial resolution is of the order of the wavelength of the ultrasonic wave in the medium. red cells in blood) to be measured, as shown in the Doppler equation. Axial resolution is the ability to see the two structures that are side by side as separate and distinct when parallel to the beam. Super-resolution ultrasound imaging method for microvasculature Lateral resolution is the image generated when the two structures lying side by side are perpendicular to the beam. This information needs to be converted to Cartesian coordinate data using fast Fourier transform functions. Axial resolution, also known as longitudinal, depth or linear resolution resolution is resolution in the direction parallel to the ultrasound beam.The resolution at any point along the beam is the same; therefore axial resolution is not affected by depth of imaging. Axial or longitudinal resolution (image quality) is related to SPL. Again, the smaller the number the more accurate is the image. Lowering of the magnitude of velocity and the transducer's pulse repetition frequency leads to deliberate reduction in temporal resolution, so that aliasing occurs for the detection of low velocities or for specific measurements, for example, regurgitant orifice area by the proximal isovelocity surface area method. With axial resolution, objects exist at relatively the same depths, which means they're generally unaffected by depth of imaging. UOG videoclip: Prenatal diagnosis and characterization of extra-axial