MRI method and apparatus for rapid acquisition of multiple views through a volume

A magnetic resonance imaging apparatus comprising:

• a magnet system which creates a temporally constant magnetic field through an examination region in which at least a portion of an object to be imaged is placed;
• a radio frequency excitation system which applies radio frequency magnetic field excitation to a volume of interest of the object to be imaged;
• a receiver system which detects and demodulates magnetic resonance data from the volume of interest;
• and
• a magnetic field encoding system which applies encoding magnetic field gradients to provide spatial discrimination of magnetic resonance data from the volume of interest, the magnetic field encoding system spatially encodes the magnetic resonance signal data along a preselected k-space sampling trajectory, the k-space sampling trajectory covering at least a part of each of two intersecting planes of k-space data.

A magnetic resonance imaging apparatus comprising:

• a means for creating a temporally constant magnetic field through an examination region in which at least a portion of an object to be imaged is placed;
• a means for applying radio frequency magnetic field excitation to a volume of interest of the object to be imaged;
• a means for detecting and demodulating magnetic resonance data from the volume of interest;
• and
• a means for spatially encoding the magnetic resonance signal data along a preselected k-space read trajectory which coincides with partial planes of data forming a dihedral surface and having a line of intersection therebetween, portions of the trajectory near the line of intersection of said partial planes deviating from said partial planes to traverse a smooth curve between the partial planes.

A method of diagnostic imaging comprising:

• establishing a polarizing magnetic field in an examination region;
• applying a radio frequency pulse to excite magnetic resonance in a volume of interest as a whole;
• after exciting magnetic resonance in the whole volume, simultaneously sampling and spatially encoding the excited magnetic resonance, to collect data for two half-planes of k-space data forming a dihedral surface and having a line of intersection therebetween passing through a nominal center of k-space;
• generating a full plane data set from each half-plane of data collected using conjugate symmetry;
• and
• the k-space data collected along a sampling trajectory comprising one of:
• a dihedral spiral trajectory;
• lines of data that run orthogonal to the line of intersection between the planes;
• and
• lines of data that run parallel to the line of intersection between the planes.

A method of diagnostic imaging comprising:

• establishing a polarizing magnetic field in an examination region;
• applying a radio frequency pulse to excite magnetic resonance in a volume of interest as a whole;
• after exciting magnetic resonance in the whole volume, simultaneously sampling and spatially encoding the excited magnetic resonance, to collect k-space data;
• said k-space data collected along a k-space trajectory covering two half-planes of data forming a dihedral surface and having a line of intersection therebetween passing through a nominal center of k-space;
• and
• said k-space trajectory having adjacent lines of k-space data which are of the same gradient frequency encoding polarity.

A method of diagnostic imaging comprising:

• establishing a polarizing magnetic field in an examination region;
• applying a radio frequency pulse to excite magnetic resonance in a volume of interest as a whole;
• after exciting magnetic resonance in the whole volume, spatially encoding the excited magnetic resonance by applying first, second, and third magnetic field gradients along first, second, and third mutually orthogonal axes to define a k-space trajectory;
• the first magnetic field gradient, along the first axis, being generally sinusoidal and having a generally constant amplitude, the first magnetic field gradient for inducing field echoes and for frequency encoding each echo;
• the second magnetic field gradient, along the second axis, being a series of phase encoding blips, each phase encoding blip for stepping each echo to another line of k-space;
• the third magnetic field gradient, along the third axis, being a generally sawtooth waveform so as to perturb the frequency encoding gradient, defining portions of different spatial orientation;
• and
• sampling k-space data at periodic intervals to collect data along the k-space trajectory which lies along a plurality of intersecting planes or partial planes corresponding to a differently angled view through the volume of interest without collecting a complete three-dimensional k-space data set.