Method for magnetic resonance imaging of an object

Claim 1

A method of producing an image of the interior of a three dimensional object having an x-axis, a y-axis and a z-axis using magnetic resonance comprising the steps of: generating a uniform magnetic field to magnetize said object; generating a first, second, and third changing magnetic field along said x-axis, said y-axis and said z-axis, respectively; generating a series of non-selective composite hard RF pulses to produce transverse magnetization within said object, said series of non-selective composite hard RF pulses including at least one pulse generated along a first axis and at least one pulse generated along a second axis; receiving a series of gradient echoes in response to said generated composite RF pulses; and producing an image of said object from said series of received gradient echoes.

Claim 2

A method of producing an image of the interior of a three dimensional object having an x-axis, a y-axis and a z-axis using magnetic resonance comprising the steps of: generating a uniform magnetic field to magnetize said object; generating a first, second, and third changing magnetic field along said x-axis, said y-axis and said z-axis, respectively; generating a series of non-selective composite hard RF pulses to produce transverse magnetization within said object, said series of non-selective composite hard RF pulses including at least one pulse generated along a first axis and at least one pulse generated along a second axis; receiving a series of gradient echoes in response to said generated composite RF pulses; and producing an image of said object from said series of received gradient echoes.

Claim 5

A method of producing an image of the interior of a three dimensional object having an x-axis, a y-axis and a z-axis using magnetic resonance comprising the steps of: generating a uniform magnetic field to magnetize said object; generating a first, second, and third changing magnetic field along said x-axis, said y-axis and said z-axis, respectively; generating a series of non-selective composite hard RF pulses to produce transverse magnetization within said object; producing asymmetric fractional echoes in response to said generation of said non-selective composite hard RF pulses; receiving said asymmetric fractional echoes produced in response to said generation of said non-selective composite hard RF pulses; and producing an image of said object from said series of received asymmetric fractional echoes.

Claim 6

A method of producing an image of the interior of a three dimensional object having an x-axis, a y-axis and a z-axis using magnetic resonance comprising the steps of: generating a uniform magnetic field to magnetize said object; generating a first, second, and third changing magnetic field along said x-axis, said y-axis and said z-axis, respectively; generating a series of non-selective composite hard RF pulses to produce transverse magnetization within said object; producing asymmetric fractional echoes in response to said generation of said non-selective composite hard RF pulses; receiving said asymmetric fractional echoes produced in response to said generation of said non-selective composite hard RF pulses; and producing an image of said object from said series of received asymmetric fractional echoes.

Claim 8

A method of producing an image of the interior of a three dimensional object having an x-axis, a y-axis and a z-axis using magnetic resonance comprising the steps of: generating a uniform magnetic field to magnetize said object; generating a first, second, and third changing magnetic field along said x-axis, said y-axis and said z-axis, respectively; generating a series of non-selective composite hard RF pulses to produce transverse magnetization within said object, said step of generating a series of non-selective composite hard RF pulses including the steps of generating a first series of RF pulses, each having a flip angle of approximately 20 degrees, along said x-axis for approximately 200 microseconds and spoiling non-resonant longitudinal magnetization; receiving a series of gradient echoes in response to said generated composite RF pulses; and producing an image of said object from said series of received gradient echoes.

Claim 9

A method of producing an image of the interior of a three dimensional object having an x-axis, a y-axis and a z-axis using magnetic resonance comprising the steps of: generating a uniform magnetic field to magnetize said object; generating a first, second, and third changing magnetic field along said x-axis, said y-axis and said z-axis, respectively; generating a series of non-selective composite hard RF pulses to produce transverse magnetization within said object, said step of generating a series of non-selective composite hard RF pulses including the steps of generating a first series of RF pulses, each having a flip angle of approximately 20 degrees, along said x-axis for approximately 200 microseconds and spoiling non-resonant longitudinal magnetization; receiving a series of gradient echoes in response to said generated composite RF pulses; and producing an image of said object from said series of received gradient echoes.

Claim 12

A method of producing an image of the interior of a three dimensional object having an x-axis, a y-axis and a z-axis using magnetic resonance comprising the steps of: generating a uniform magnetic field to magnetize said object; generating a first, second, and third changing magnetic field along said x-axis, said y-axis and said z-axis, respectively; generating a series of non-selective composite hard RF pulses to produce transverse magnetization within said object, said series of non-selective composite hard RF pulses including at least one pulse generated along a first axis and at least one pulse generated along a second axis, said step of generating said series of non-selective composite hard RF pulses including the step of generating a first series of hard RF pulses, each having a flip angle of approximately 20 degrees, along said x-axis; reducing said repetition time TR between the generation of successive composite hard RF pulses; receiving a series of gradient echoes in response to said generated composite RF pulses; and producing an image of said object from said series of received gradient echoes.

Claim 13

A method of producing an image of the interior of a three dimensional object having an x-axis, a y-axis and a z-axis using magnetic resonance comprising the steps of: generating a uniform magnetic field to magnetize said object; generating a first, second, and third changing magnetic field along said x-axis, said y-axis and said z-axis, respectively; generating a series of non-selective composite hard RF pulses to produce transverse magnetization within said object, said series of non-selective composite hard RF pulses including at least one pulse generated along a first axis and at least one pulse generated along a second axis, said step of generating said series of non-selective composite hard RF pulses including the step of generating a first series of hard RF pulses, each having a flip angle of approximately 20 degrees, along said x-axis; reducing said repetition time TR between the generation of successive composite hard RF pulses; receiving a series of gradient echoes in response to said generated composite RF pulses; and producing an image of said object from said series of received gradient echoes.

Claim 15

A method of magnetic resonance imaging of the interior of a three dimensional object having a first axis, a second axis, and a third axis, comprising the steps of: generating a uniform magnetic field to magnetize said object; generating a first non-selective hard RF pulse along said first axis to produce transverse magnetization within said object; generating a first phase encoding pulse along said first axis; generating a first phase encoding pulse along said third axis; generating a frequency encoding pulse along said second axis, said frequency encoding pulse comprised of a de-phasing portion and a re-phasing portion, said first phase encoding pulse, said second phase encoding pulse and said de-phasing portion of said frequency encoding pulse generated simultaneously; producing an asymmetrical fractional gradient echo containing information related to said object being imaged, said asymmetrical fractional gradient echo produced during said re-phasing portion of said frequency encoding pulse; selecting a next phase encoding pulse along said first axis and a next phase encoding pulse along said third axis; repeating said steps of generating a first non-selective hard RF pulse along said first axis, simultaneously generating said next phase encoding pulses along said first and third axes and said de-phasing portion of said frequency encoding pulse along said second axis, and producing a next asymmetrical fractional gradient echo containing information related to said object being imaged until an asymmetrical fractional gradient echo corresponding to last phase encoding pulses along said first and third axes has been produced; and producing an image of said object from said series of produced asymmetrical fractional gradient echoes.

Claim 16

A method of magnetic resonance imaging of the interior of a three dimensional object having a first axis, a second axis, and a third axis, comprising the steps of: generating a uniform magnetic field to magnetize said object; generating a first non-selective hard RF pulse along said first axis to produce transverse magnetization within said object; generating a first phase encoding pulse along said first axis; generating a first phase encoding pulse along said third axis; generating a frequency encoding pulse along said second axis, said frequency encoding pulse comprised of a de-phasing portion and a re-phasing portion, said first phase encoding pulse, said second phase encoding pulse and said de-phasing portion of said frequency encoding pulse generated simultaneously; producing an asymmetrical fractional gradient echo containing information related to said object being imaged, said asymmetrical fractional gradient echo produced during said re-phasing portion of said frequency encoding pulse; selecting a next phase encoding pulse along said first axis and a next phase encoding pulse along said third axis; repeating said steps of generating a first non-selective hard RF pulse along said first axis, simultaneously generating said next phase encoding pulses along said first and third axes and said de-phasing portion of said frequency encoding pulse along said second axis, and producing a next asymmetrical fractional gradient echo containing information related to said object being imaged until an asymmetrical fractional gradient echo corresponding to last phase encoding pulses along said first and third axes has been produced; and producing an image of said object from said series of produced asymmetrical fractional gradient echoes.

Claim 26

A method of producing a fast, high SNR image of a knee comprising the steps of: generating a uniform magnetic field; generating a first series of non-selective hard RF pulses of a duration approximately equal to 200 microseconds along a first axis; generating a series of phase encoding pulses along said first axis; generating a series of phase encoding pulses along a third axis; generating a series of frequency encoding pulses along a second axis, each of said frequency encoding pulses comprised of a de-phasing portion and a re-phasing portion, said first phase encoding pulses, said second phase encoding pulses and said de-phasing portions of said frequency encoding pulses generated simultaneously; producing a series of asymmetrical fractional gradient echoes during said re-phasing portion of said frequency encoding pulses; and producing an image of said knee from said series of produced asymmetrical fractional gradient echoes.

Claim 27

A method of producing a fast, high SNR image of a knee comprising the steps of: generating a uniform magnetic field; generating a first series of non-selective hard RF pulses of a duration approximately equal to 200 microseconds along a first axis; generating a series of phase encoding pulses along said first axis; generating a series of phase encoding pulses along a third axis; generating a series of frequency encoding pulses along a second axis, each of said frequency encoding pulses comprised of a de-phasing portion and a re-phasing portion, said first phase encoding pulses, said second phase encoding pulses and said de-phasing portions of said frequency encoding pulses generated simultaneously; producing a series of asymmetrical fractional gradient echoes during said re-phasing portion of said frequency encoding pulses; and producing an image of said knee from said series of produced asymmetrical fractional gradient echoes.

Claim 36

A method of producing a fast, high SNR image of a brain comprising the steps of: generating a uniform magnetic field; generating a first series of non-selective hard RF pulses having a twenty degree flip angle along a first axis; generating a series of spoiler pulses along said first axis to produce T1 contrast; generating a series of phase encoding pulses along said first axis; generating a series of phase encoding pulses along a third axis; generating a series of frequency encoding pulses along a second axis, said frequency encoding pulse comprised of a de-phasing portion and a re-phasing portion, said spoiler pulses generated before said phase encding pulses along said first and third axes, said phase encoding pulses along said first and third axes and said de-phasing portions of said frequency encoding pulses generated simultaneously; producing a series of asymmetrical fractional gradient echoes during said re-phasing portion of said frequency encoding pulses; and producing an image of said brain from said series of produced asymmetrical fractional gradient echoes.

Claim 37

A method of producing a fast, high SNR image of a brain comprising the steps of: generating a uniform magnetic field; generating a first series of non-selective hard RF pulses having a twenty degree flip angle along a first axis; generating a series of spoiler pulses along said first axis to produce T1 contrast; generating a series of phase encoding pulses along said first axis; generating a series of phase encoding pulses along a third axis; generating a series of frequency encoding pulses along a second axis, said frequency encoding pulse comprised of a de-phasing portion and a re-phasing portion, said spoiler pulses generated before said phase encding pulses along said first and third axes, said phase encoding pulses along said first and third axes and said de-phasing portions of said frequency encoding pulses generated simultaneously; producing a series of asymmetrical fractional gradient echoes during said re-phasing portion of said frequency encoding pulses; and producing an image of said brain from said series of produced asymmetrical fractional gradient echoes.