US6587707B2
Expired / Lapsed
US
⏱️ 0.0 years remaining
MR imaging method with motion compensation
Assignee: Koninklijke Philips NV
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Filing: 2001-06-13
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Granted: 2003-07-01
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Expires: 2021-06-13
Abstract
Abstract An MR imaging method wherein motion of an object to be imaged is examined during a preparation phase preceding the actual MR examination. The necessary sequences for the subsequent MR examination are modified during the examination to compensate for the motion based on motion parameters calculated during the preparation phase or motion parameters derived from the motion parameters calculated during the preparation phase based on a correlation between the motion parameters.
Inventors
- 👤 Kay Nehrke
- 👤 Peter Boernert
- 👤 Bernd Aldefeld
- 👤 Michael Harald Kuhn
- 👤 Dirk Manke
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 22:21
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/20; G01R33/44; G01R33/48; G01R33/54; G01R33/56; G01R33/567; G01R33/5676
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
143 words
A method for MR imaging of a moving object in an examination zone, comprising: correlating a plurality of motion parameters, measuring a variation in time of the correlated motion parameters during a preparation phase preceding an examination phase, measuring only a portion of the correlated motion parameters during the examination phase, deriving a remaining portion of the motion parameters which were not measured from the measured portion of the correlated motion parameters, exciting the nuclear magnetization in the presence of a steady magnetic field by sequences which include at least a respective RF pulse of defined frequency, evaluating MR signals received with a defined phase position and produced under the influence of additional magnetic gradient fields, and varying at least one parameter of the sequence based on at least one of the derived or measured motion parameters in order to achieve motion compensation.
Claim 2
Independent Claim
143 words
A method for MR imaging of a moving object in an examination zone, comprising: correlating a plurality of motion parameters, measuring a variation in time of the correlated motion parameters during a preparation phase preceding an examination phase, measuring only a portion of the correlated motion parameters during the examination phase, deriving a remaining portion of the motion parameters which were not measured from the measured portion of the correlated motion parameters, exciting the nuclear magnetization in the presence of a steady magnetic field by sequences which include at least a respective RF pulse of defined frequency, evaluating MR signals received with a defined phase position and produced under the influence of additional magnetic gradient fields, and varying at least one parameter of the sequence based on at least one of the derived or measured motion parameters in order to achieve motion compensation.
Claim 3
Dependent Claim
36 words
A method as claimed in claim 1 , further comprising: deriving at least two motion parameters for a motion direction from the measured motion parameters, and varying the magnetic gradient fields to provide additional motion compensation.
Claim 4
Dependent Claim
20 words
A method as claimed in claim 1 , further comprising using navigator pulses for the measurement of the motion parameters.
Claim 5
Dependent Claim
23 words
A method as claimed in claim 1 wherein the object is a heart, further comprising generating the sequences under control of an ECG.
Claim 6
Dependent Claim
25 words
A method as claimed in claim 4 , further comprising generating a number of successive sequences per cardiac cycle after measurement of the motion parameters.
Claim 7
Independent Claim
172 words
An apparatus for MR imaging of a moving object, comprising: a magnet for generating a uniform, steady magnetic field, an RF transmitter for generating magnetic RF pulses, a receiver for receiving MR signals, a generator for generating gradient magnetic fields with gradients that vary differently in time and space, an evaluation unit for processing the received MR signals, and a control unit arranged to control the RF transmitter, the receiver, the generator and the evaluation unit, the control unit being programmed to measure a variation in time of a plurality of correlated motion parameters during a preparation phase preceding an examination phase, measure only a portion of the correlated motion parameters during the examination phase, derive a remaining portion of the motion parameters which are not measured during the examination phase from the measured motion parameters and vary at least one parameter of a sequential generation of the magnetic field during the examination phase based on at least one of the derived or measured motion parameters in order to achieve motion compensation.
Claim 8
Independent Claim
172 words
An apparatus for MR imaging of a moving object, comprising: a magnet for generating a uniform, steady magnetic field, an RF transmitter for generating magnetic RF pulses, a receiver for receiving MR signals, a generator for generating gradient magnetic fields with gradients that vary differently in time and space, an evaluation unit for processing the received MR signals, and a control unit arranged to control the RF transmitter, the receiver, the generator and the evaluation unit, the control unit being programmed to measure a variation in time of a plurality of correlated motion parameters during a preparation phase preceding an examination phase, measure only a portion of the correlated motion parameters during the examination phase, derive a remaining portion of the motion parameters which are not measured during the examination phase from the measured motion parameters and vary at least one parameter of a sequential generation of the magnetic field during the examination phase based on at least one of the derived or measured motion parameters in order to achieve motion compensation.
Claim 9
Independent Claim
112 words
A device for generating a computer program for a control unit for controlling an MR imaging apparatus, comprising: means for measuring the variation in time of a plurality of correlated motion parameters during a preparation phase preceding an examination phase, means for measuring only a portion of the correlated motion parameters during the examination phase, means for deriving the motion parameters which are not measured during the examination phase from the measured motion parameters, and means for varying at least one parameter of a sequential generation of a magnetic field during the examination phase based on at least one of the derived or measured motion parameters in order to achieve motion compensation.
Claim 10
Independent Claim
112 words
A device for generating a computer program for a control unit for controlling an MR imaging apparatus, comprising: means for measuring the variation in time of a plurality of correlated motion parameters during a preparation phase preceding an examination phase, means for measuring only a portion of the correlated motion parameters during the examination phase, means for deriving the motion parameters which are not measured during the examination phase from the measured motion parameters, and means for varying at least one parameter of a sequential generation of a magnetic field during the examination phase based on at least one of the derived or measured motion parameters in order to achieve motion compensation.
Claim 11
Dependent Claim
25 words
A method as claimed in claim 1 , wherein the at least one parameter of the sequence is varied based on a derived motion parameter.
Claim 12
Dependent Claim
26 words
A method as claimed in claim 1 , wherein a plurality of parameters of the sequence are varied based on the derived or measured motion parameters.
Claim 13
Dependent Claim
23 words
A method as claimed in claim 1 , wherein the variation in time of the correlated motion parameters is measured using navigator pulses.
Claim 14
Dependent Claim
31 words
A method as claimed in claim 1 , wherein the object is a heart, the variation in time of the correlated motion parameters being measured during respiratory cycles using navigator pulses.
Claim 15
Dependent Claim
19 words
A method as claimed in claim 1 , wherein only one motion parameter is measured during the examination phase.
Claim 16
Dependent Claim
39 words
A method as claimed in claim 1 , wherein the parameters of the sequence which vary based on the motion parameters include the frequency of the RF pulse, the phase position of the RF pulse, and the magnetic field.
Claim 17
Dependent Claim
51 words
A method as claimed in claim 1 , wherein the object is a heart, further comprising selecting the motion parameters as motion at a point on the diaphragm, motion at a point at an upper edge of the heart and motion at a point at a lower edge of the heart.
Claim 18
Dependent Claim
25 words
A method as claimed in claim 1 , wherein the variation in time of the correlated motion parameters is measured simultaneously during the preparation phase.
Claim 19
Dependent Claim
27 words
An apparatus as claimed in claim 6 , wherein the control unit is arranged to vary the at least one parameter based on a derived motion parameter.
Claim 20
Dependent Claim
28 words
An apparatus as claimed in claim 6 , wherein the control unit is arranged to measure the variation in time of the correlated motion parameters using navigator pulses.
Claim 21
Dependent Claim
24 words
An apparatus as claimed in claim 6 , wherein the control unit is arranged to measure only one motion parameter during the examination phase.
Claim 22
Dependent Claim
39 words
An apparatus as claimed in claim 6 , wherein the at least one parameter which vary based on the motion parameters include the frequency of the RF pulse, the phase position of the RF pulse or the magnetic field.
Claim 23
Dependent Claim
48 words
An apparatus as claimed in claim 6 , wherein the object is a heart, the motion parameters being motion at a point on the diaphragm, motion at a point at an upper edge of the heart and motion at a point at a lower edge of the heart.
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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) | 2006-06-30 | 2006-12-30 | 2007-07-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2010-06-30 | 2010-12-30 | 2011-07-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2014-06-30 | 2014-12-30 | 2015-07-01 | $7700.00 | Window Closed / Lapsed |