Inherently de-coupled sandwiched solenoidal array coil

A quadrature detection sandwiched solenoidal array coil arrangement for receiving NMR signals in a MRI apparatus, said array coil comprising:

• a first solenoidal loop coil having one or more conductive windings;
• at least two further, spatially separated, solenoidal coil sections, each section having one or more conductive windings, disposed so that at least one section is located at opposite axial ends of the first solenoidal loop coil such that the first solenoidal loop coil is effectively sandwiched between the two separated sections and magnetic fields emanating from the separated sections become a null at the center of the first solenoidal loop coil;
• and
• a saddle coil coaxially oriented with respect to the first solenoidal loop coil and disposed between the solenoidal loop coil, the two separated sections, wherein the first solenoidal loop coil, the separated coil sections and saddle coil together form an array coil which is oriented such that the magnetic field axis of the solenoidal loop coil and the magnetic field axis of the saddle coil are orthogonal to each other and to a main static polarizing magnetic field axis, B0, of the MRI apparatus.

A method for imaging a breast of a prone patient laying in an MRI apparatus having a vertical main static polarizing magnetic field, said method comprising the steps of:

• a) fitting a breast of said prone patient into an open axial end of a sandwiched solenoidal array coil comprising a plurality of coaxial coil elements wherein at least one coil element is a solenoidal loop coil sandwiched between a separated pair of solenoidal coil sections;
• b) orienting the sandwiched solenoidal array coil within the MRI apparatus such that a RF magnetic field. {overscore (B)}1, produced by the solenoidal loop coil is substantially orthogonal to the vertical main static polarizing magnetic field of the MRI apparatus;
• and
• c) using said sandwiched solenoidal array coil to receive NMR signals during an imaging operation of the MRI apparatus.

A method for imaging a breast a prone patient laying in a horizontal main field MRI apparatus, said method comprising the steps of:

• a) fitting a patient with a sandwiched solenoidal array coil comprising a plurality of coaxial coil elements wherein at least one coil element is a solenoidal loop coil sandwiched between separated solenoidal coil sections and wherein the solenoidal loop coil of the array is of a large diameter and is fitted over the torso and breast of the patient and the separated coil sections of the array are fitted such that the breast is sandwiched between the separated coil sections;
• b) orienting the sandwiched solenoidal array coil within the MRI apparatus such that a RF magnetic field, {overscore (B)}1, of the solenoidal loop coil is substantially orthogonal to a horizontal main static polarizing magnetic field of the MRI apparatus;
• and
• c) using said sandwiched solenoidal array coil to receive NMR signals during an imaging operation of the MRI apparatus.

In a MRI system having multiple data acquisition channels for producing images from NMR signals emanating from a subject irradiated with an RF excitation pulse in the presence of a static polarizing magnetic field, said system having a sandwiched solenoidal array coil for receiving the NMR signals emanating from a region of interest in the subject, said sandwiched solenoidal array coil comprising a plurality of coil elements wherein at least one coil element is a solenoidal loop coil sandwiched between a pair of solenoidal coil sections, a method for selectively obtaining differently sized FOVs of an imaged region of interest, said method comprising the steps of:

• a) providing NMR signals received by a selected first solenoidal loop coil to a first data acquisition channel of the MRI system for processing;
• b) providing NMR signals received by a sandwiching pair of solenoidal coil sections to a second data acquisition channel of the MRI system for processing;
• and
• c) selecting between:
• (i) processing signal data acquired from both the first and the second data acquisition channels and combining processed data to produce an image or (ii) processing signal data acquired from a selected single data acquisition channel to produce an image, wherein an image produced from combined data acquired from both the first and the second data acquisition channels results in an FOV of enhanced size compared to an image produced from a single data acquisition channel alone.

In an MRI system having multiple data acquisition channels for producing images from NMR signals emanating from a subject irradiated with a sequence of RF excitation pulses in the presence of a static polarizing magnetic field and associated sequences of orthogonal gradients therein, said system having a one or more sandwiched solenoidal array coils for receiving the NMR signals emanating from one or more regions of interest in the subject, said sandwiched solenoidal array coils comprising a plurality of coil elements wherein at least one coil element is a first solenoidal loop coil and at least one coil element is a split-apart solenoidal loop disposed to encompass the first solenoidal loop, a method for selectively obtaining images from different regions of interest in the subject, said method comprising the steps of:

• a) providing NMR signals received by a first sandwiched solenoidal array coil, selectively located at a first region of interest on a subject, to a first data acquisition channel of the MRI system for processing;
• b) providing NMR signals received by a second sandwiched solenoidal array coil, selectively located at a second region of interest on a subject, to a second data acquisition channel of the MRI system for processing;
• and
• c) selecting between processing signal data acquired from the first data acquisition channel or the second data acquisition channel to produce an image, wherein an image produced from the first data acquisition channel covers a different region of interest than an image produced from the second data acquisition channel.

In a MRI system having multiple data acquisition channels for producing images from NMR signals emanating from a subject irradiated with a sequence of RF excitation pulses in the presence of a static polarizing magnetic field and associated sequences of orthogonal gradients therein, said system having a sandwiched solenoidal array coil for receiving the NMR signals emanating from a region of interest in the subject, a method for simultaneously imaging the head and neck portions of a human patient, said method comprising the steps of:

• a) fitting the head and neck portions of a patient with a sandwiched solenoidal array coil comprising separated solenoidal elements having different diameters corresponding to respective head and neck portions of a patient, at least some separated solenoidal sections having a correspondingly different quantity of conductive windings such that magnetic fields emanating from the sections become a null at the center of another at least one solenoidal loop coil element;
• b) orienting the sandwiched solenoidal array coil within the MRI apparatus such that its RF magnetic field, {overscore (B)}1, is substantially orthogonal to the main polarizing magnetic field of the MRI apparatus;
• and
• c) using said sandwiched solenoidal array coil to receive NMR signals during an imaging operation of the MRI apparatus.