MRE/Wave beta release General functions mrewave home data types reserved data input files output files clipboard resolution 1d plots 2d plots Wave inversion functions wave test data wave data wave parameters wave output wave unwrap wave filters wave lfe fftw faq known bugs |  |
Wave Inversion - parameters
mech freq(hz): The frequency of mechanical vibration used to induce shear waves in the object, in hertz (cycles per second). fov(x/y/z)(m): FOV in meter for x, y and z directions (z ignored for 2D processing) harmonic number: one of the first steps in m estimation is the ft of the data though time. If there are n time steps, n/2-1 harmonics are available for processing. Here 0 refers to the DC term and is not valid. Normally harmonic number 1 contains most of the energy and is chosen for wave inversion. phase range: enter the equivalent of a 2 p . This value is used for phase unwrapping and calibration of measurements. phase offsets: The number of time samples in the phase data sequence. The phase samples are assumed to be evenly spaced over one full mechanical vibration cycle. menc(motion encoding): This is the conversion factor to convert a phase image (in radians) to displacement (in microns). MENC is a function of gradient amplitude, frequency and rise times. MENC is in units of mm / radian. For phase difference images using oscillating trapizodial motion sensitizing gradients, MENC can be calculated as: MENC = 1e10/(8*g*(period-2*ramp)*N*amp where: preriod = 1/frequency in ms ramp = duration ramp from 0 to full strength in ms N = number of complete cycles for the gradient waveforms amg = gradient amplitude in G/cm g = 4257 hz/g for protons

MRE/Wave beta release For future updates check: http://mayoresearch.mayo.edu/mayo/research/ehman_lab"