Abstract: A method and device of magnetic resonance imaging carry out the steps of selecting a trajectory in phase space; expressing that trajectory as a function of variables in a coordinate system suitable for driving gradient coils of an imaging system; performing variable transformation and redefinition to extract a subset of variables varying as a function of time along gradient wave forms but constant from projection to projection; calculating that subset of variables prior to imaging; storing that calculated subset of variables in a memory; and computing online gradient values during imaging with the assistance of said stored subset of variables to significantly reduce wave form memory requirements such that a gradient controller can perform required mathematical functions online.

Abstract: A method for eddy current compensated diffusion imaging using magnetic resonance is used to obtain a spin echo signal in a readout time window by excitation of a nuclear resonance signal using a first radio-frequency pulse and by refocusing that signal using at least one second radio-frequency pulse and a third radio-frequency pulse. Gradients fields are applied in a gradient field direction field having a strength and being activated by gradient pulses between each of said radio-frequency pulses and prior to said readout window, said gradient pulses having a polarity which is alternated between successive gradient pulses, with a totality of said gradient pulses having a gradient time integral of zero between a time of said excitation and the center of kx or k-space. At least two of said gradient pulses have differing gradient time integrals. The gradient direction is then changed and the previous steps repeated to evenly distribute gradient direction vectors over a sphere.

Abstract: A method for eddy current compensated diffusion imaging using magnetic resonance is used to obtain a spin echo signal in a readout time window by excitation of a nuclear resonance signal using a first radio-frequency pulse and by refocusing that signal using at least one second radio-frequency pulse and a third radio-frequency pulse. Gradients fields are applied in a gradient field direction field having a strength and being activated by gradient pulses between each of said radio-frequency pulses and prior to said readout window, said gradient pulses having a polarity which is alternated between successive gradient pulses, with a totality of said gradient pulses having a gradient time integral of zero between a time of said excitation and the center of kx or k-space. At least two of said gradient pulses have differing gradient time integrals. The gradient direction is then changed and the previous steps repeated to evenly distribute gradient direction vectors over a sphere.

Abstract: A method and device of magnetic resonance imaging carry out the steps of selecting a trajectory in phase space; expressing that trajectory as a function of variables in a coordinate system suitable for driving gradient coils of an imaging system; performing variable transformation and redefinition to extract a subset of variables varying as a function of time along gradient wave forms but constant from projection to projection; calculating that subset of variables prior to imaging; storing that calculated subset of variables in a memory; and computing online gradient values during imaging with the assistance of said stored subset of variables to significantly reduce wave form memory requirements such that a gradient controller can perform required mathematical functions online.

Abstract: A method predicting stroke evolution uses magnetic resonance diffusion and perfusion images obtained shortly after the onset of stroke symptoms to automatically estimate the eventual volume of dead cerebral tissue resulting from the stroke. The diffusion and perfusion images are processed to extract region(s) of interest presenting tissue at risk of infarction. A midplane algorithm is also used to calculate ratio and diffusion and perfusion measures for modelling infarct evolution. A parametric normal classifier algorithm is used to predict infarct growth using the calculated measures.