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1.发明申请公开(公告)号：US20180172784A1
公开(公告)日：2018-06-21
申请号：US15577860
申请日：2016-05-30
IPC分类号： G01R33/28 , A61B34/20 , G01R33/565
CPC分类号： G01R33/287 , A61B34/20 , A61B2034/2051 , A61B2090/374 , A61B2090/502 , G01R33/56509
摘要： The invention relates to a system and a method for tracking position and orientation of an object in a magnetic resonance (MR) apparatus. The system comprises a tracking device for electromagnetic measurements of position and orientation with a) a tracker structure (2) that is firmly attachable to the object (4) of which the position and orientation are to be measured; b) retransmitter means (6; 8a, 8b, 8c) firmly attached to said tracker structure, said retransmitter means having at least one retransmitter resonance frequency; and c) electrical circuitry means including: i) transmitter means (10) for transmitting an electromagnetic field with at least one of said retransmitter resonance frequencies; ii) receiver means (12; 14a,14b) for receiving an electromagnetic field retransmitted by said retransmitter means; said receiver means converting said electromagnetic field into a proportional voltage; and iii) calculating means for determining, from said proportional voltages obtained from said receiver means, a position and orientation of said retransmitter means, and concomitantly of said object. The tracking device can be used in an operating MR imaging or spectroscopy apparatus.
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公开(公告)号：US20180136298A1
公开(公告)日：2018-05-17
申请号：US15573284
申请日：2016-05-12
IPC分类号： G01R33/565 , G01R33/389 , G01R33/58 , G01R33/46
CPC分类号： G01R33/56518 , G01R33/389 , G01R33/4625 , G01R33/58
摘要： A method of determining an actual gradient impulse response function during execution of a magnetic resonance (MR) imaging or spectroscopy sequence, wherein a main magnetic field is generated in a sample region of an MR apparatus by means of a main magnet and wherein superimposed time dependent gradient fields and radiofrequency fields in a first RF band are generated in the sample region according to a first MR sequence for forming images or spectra, the gradient fields being generated by gradient forming means of the MR apparatus operated according to a gradient forming sequence part of said first MR sequence, the MR apparatus further comprising at least one magnetic field probe. The method comprises the steps of: —operating said at least one magnetic field probe according to a second sequence, whereby a time dependent probe signal is repeatedly acquired from each magnetic field probe during a probe acquisition time window, thus providing at least one time dependent probe signal; —obtaining said actual gradient impulse response function by calculating an impulse response function from said at least one time dependent probe signal and from said gradient forming sequence part.
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公开(公告)号：US10379190B2
公开(公告)日：2019-08-13
申请号：US15573284
申请日：2016-05-12
IPC分类号： G01R33/565 , G01R33/389 , G01R33/58 , G01R33/46
摘要： A method of determining an actual gradient impulse response function during execution of a magnetic resonance (MR) imaging or spectroscopy sequence, wherein a main magnetic field is generated in a sample region of an MR apparatus by means of a main magnet and wherein superimposed time dependent gradient fields and radiofrequency fields in a first RF band are generated in the sample region according to a first MR sequence for forming images or spectra, the gradient fields being generated by gradient forming means of the MR apparatus operated according to a gradient forming sequence part of said first MR sequence, the MR apparatus further comprising at least one magnetic field probe. The method comprises the steps of: —operating said at least one magnetic field probe according to a second sequence, whereby a time dependent probe signal is repeatedly acquired from each magnetic field probe during a probe acquisition time window, thus providing at least one time dependent probe signal; —obtaining said actual gradient impulse response function by calculating an impulse response function from said at least one time dependent probe signal and from said gradient forming sequence part.
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