Acceleration of magnetic resonance elastography (mre) using distributed encoding

A magnetic resonance imaging (MRI) system for generating a map indicative of a subject tissue's mechanical properties, the system comprising:

• a magnet system configured to generate a polarizing magnetic field to the subject tissue;
• a plurality of gradient coils configured to apply a magnetic field gradient to the polarizing magnetic field;
• a radio frequency (RF) system configured to apply an excitation field to the subject tissue;
• a driver configured to deliver a stress to the subject for propagating mechanical waves through the subject tissue;
• a control device coupled to the MRI system, the control device comprising a controller configured to perform a plurality of operations in accordance with machine readable instructions stored in a digital memory, wherein the plurality of operations includes:
• encoding a series of motions and obtaining MRE data samples in a plurality of directions at a predetermined number of time points, the encoding motion and obtaining samples performed according to an Elastography with Distributed, Generalized Encoding (EDGE) matrix, comprising encoding and obtaining samples along an optimized set of gradient vector directions distributed in a 3-dimensional gradient vector space across a surface of a sphere,
• constructing a plurality of phase images based upon the obtained MRE data samples, the plurality of phase images comprising a number of phase images in a range from 7 to 24,
• estimating shear displacement fields in the subject tissue based on the plurality of phase images, wherein estimation comprises an optimization performed according to an Elastography with Distributed, Generalized Encoding (EDGE) matrix, and
• generating the map indicative of the subject tissue's mechanical properties via an inversion algorithm.