Travelling-wave nuclear magnetic resonance method

An apparatus for magnetic resonance imaging, comprising

• a cavity for placing therein a subject or object to be imaged,
• means for applying a static magnetic field,
• means for applying gradient magnetic fields,
• means for coupling in electromagnetic excitation pulses having a predetermined operating frequency to induce nuclear magnetic resonance within the subject or object and
• means for detecting an electromagnetic signal resulting from said magnetic resonance,
• wherein said cavity, when loaded with the subject or object to be imaged, has a lowest cut-off frequency that is smaller than said operating frequency,
• wherein said means for coupling in electromagnetic excitation pulses and/or said means for detecting an electromagnetic signal comprises an antenna,
• wherein said antenna is a patch antenna or a cross-folded dipole antenna.

A method for acquiring an image or spectrum of a subject or object residing within the magnetic field of a magnetic resonance apparatus, comprising the steps of:

• executing a predetermined pulse sequence for applying gradient magnetic fields and for coupling in electromagnetic excitation pulses to induce nuclear magnetic resonance within the subject or object;
• detecting an electromagnetic signal resulting from said magnetic resonance;
• and
• constructing at least one image or magnetic resonance spectrum of said subject or object from said detected electromagnetic signal;
• wherein said coupling in and/or detection of the electromagnetic excitation pulse is carried out substantially by means of an axially travelling electromagnetic wave in said cavity propagating from a proximal cavity end to a distal cavity end;
• wherein said axially travelling wave comprises a plurality of more than two linearly independent propagating field patterns.

An apparatus for magnetic resonance imaging or spectroscopy, comprising

• a cavity for placing therein a subject or object to be imaged,
• means for applying a static magnetic field,
• means for applying gradient magnetic fields,
• means for coupling in electromagnetic excitation pulses having a predetermined operating frequency to induce nuclear magnetic resonance within the subject or object and
• means for detecting an electromagnetic signal resulting from said magnetic resonance,
• wherein said cavity, when loaded with the subject or object to be imaged, has a lowest cut-off frequency that is smaller than said operating frequency,
• wherein a plurality of transmitter elements are located at a proximal cavity end, a plurality of receiver elements are located at a distal cavity end, and a plurality of dielectric inserts are arranged between said proximal cavity end and a cavity region for receiving the subject or object.