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US5243283A Expired / Lapsed US ⏱️ 0.0 years remaining

Method of nuclear magnetic resonance angiographic imaging with reduced imaging operation time

Assignee: Toshiba Corp
•
Filing: 1991-06-21
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Granted: 1993-09-07
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Expires: 2011-06-21
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Abstract

Abstract A method of nuclear magnetic resonance angiographic imaging capable of reducing an imaging operation time. The method includes the steps of: applying a plurality of pre-saturation excitation pulses sequentially to a pre-saturation section located over the flowing stream within an imaging region of the patient formed along the flowing stream, so as to pre-saturate the flowing stream located at the pre-saturation section at a time of application of each of the pre-saturation excitation pulses; dispersing and deleting transverse components of spins due to the pre-saturation excitation pulses applied at the applying step; exciting the imaging region by applying a single imaging excitation pulse and by using appropriate gradient magnetic fields, such that nuclear magnetic resonance signals are produced from the imaging region; and collecting the nuclear magnetic resonance signals from the imaging region by using appropriate gradient magnetic fields, and obtaining a nuclear magnetic resonance image showing a plurality of pre-saturated patterns corresponding to a plurality of the pre-saturation excitation pulses by processing the nuclear magnetic resonance signals.

Inventors

  • 👤 Yu Tokunaga
  • 👤 Hiroshi Sugimoto

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-30 15:05
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/20; G01R33/44; G01R33/48; G01R33/54; G01R33/56; G01R33/563; G01R33/56308; G01R33/56333

Claims Analysis

Total Claims: 6
Claim 1
Independent Claim 191 words
A method of nuclear magnetic resonance angiographic imaging for taking a nuclear magnetic resonance image of a flowing stream in a patient placed inside a static magnetic field, comprising the sequential steps of: applying a plurality of pre-saturation excitation pulses sequentially to a pre-saturation section located over the flowing stream within an image region of the patient formed along the flowing stream; pre-saturating a plurality of different portions of the flowing stream located at the pre-saturation section with each portion of said flowing stream pre-saturated in response to each pre-saturation excitation pulse; dispersing and deleting transverse components of spins of each different portions of the flowing stream due to the pre-saturation excitation pulses applied at the applying step; exciting the image region by applying a single imaging excitation pulse and gradient magnetic fields, such that nuclear magnetic resonance signals are produced from the imaging region; and collecting and processing the nuclear magnetic resonance signals from the imaging region by using gradient magnetic fields, and obtaining a nuclear magnetic resonance image showing a plurality of pre-saturated patterns each corresponding to a different one of the plurality of different portions of flowing stream.
Claim 2
Independent Claim 191 words
A method of nuclear magnetic resonance angiographic imaging for taking a nuclear magnetic resonance image of a flowing stream in a patient placed inside a static magnetic field, comprising the sequential steps of: applying a plurality of pre-saturation excitation pulses sequentially to a pre-saturation section located over the flowing stream within an image region of the patient formed along the flowing stream; pre-saturating a plurality of different portions of the flowing stream located at the pre-saturation section with each portion of said flowing stream pre-saturated in response to each pre-saturation excitation pulse; dispersing and deleting transverse components of spins of each different portions of the flowing stream due to the pre-saturation excitation pulses applied at the applying step; exciting the image region by applying a single imaging excitation pulse and gradient magnetic fields, such that nuclear magnetic resonance signals are produced from the imaging region; and collecting and processing the nuclear magnetic resonance signals from the imaging region by using gradient magnetic fields, and obtaining a nuclear magnetic resonance image showing a plurality of pre-saturated patterns each corresponding to a different one of the plurality of different portions of flowing stream.
Claim 3
Dependent Claim 23 words
The method of claim 1, wherein at the applying step the plurality of pre-saturation excitation pulses are applied sequentially at a predetermined interval.
Claim 4
Dependent Claim 39 words
The method of claim 1, wherein at the dispersing step the transverse components of spins are dispersed by using a gradient magnetic field having a field strength greater than that used in the exciting step and the collecting step.
Claim 5
Dependent Claim 30 words
The method of claim 1, wherein at the exciting step and the collecting step the appropriate gradient magnetic fields are given in a form of a gradient field echo sequence.
Claim 6
Dependent Claim 29 words
The method of claim 1, wherein at the exciting step and the collecting step the appropriate gradient magnetic fields are given in a form of a spin echo sequence.

References Cited (Backward Citations)

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USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1996-09-06 1997-03-08 1997-09-07 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2000-09-06 2001-03-08 2001-09-07 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2004-09-06 2005-03-08 2005-09-07 $7700.00 Window Closed / Lapsed

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