MR examining apparatus of heart beat synchronous type
First Claim
1. A magnetic resonance examining apparatus of heart beat synchronous type for imaging multiphase images in synchronism with a heart beat of a subject, said apparatus comprising:
- means for detecting a heart beat waveform of the subject;
means for generating a synchronizing signal synchronous with the heart beat waveform detected by said detecting means;
means for measuring a repetition period of said heart beat waveform on the basis of the synchronizing signal applied from said synchronizing signal generating means;
input means for inputting a previously stored setting of a repetition time for spin excitation of the subject;
means responsive to said measuring means and said input means for computing a corrected repetition time close to said spin excitation repetition time on the basis of data of said heart beam waveform repetition period supplied from said measuring means and the setting of said spin excitation repetition time supplied from said input means, said corrected repetition time having a value which, when multiplied by a factor of N (N;
an integer), becomes equal to that of said heart beat waveform repetition period;
means for setting a plurality of imaging phases so as to form nuclear magnetic resonance images; and
means for effecting spin excitation of the subject according to the corrected repetition period;
means for setting a plurality of imaging phases so as to form nuclear magnetic resonance images; and
means for effecting spin excitation of the subject according to the corrected repetition time computed by said corrected repetition time computing means and acquiring a nuclear magnetic resonance signal for each of the imaging phases set by said imaging phase setting means.
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Accused Products
Abstract
A magnetic resonance examining apparatus of heart beat synchronous type in which one heart beat period is substantially equally divided to provide a plurality of phases, and at least some of those phases are selected as imaging phases so as to obtain nuclear magnetic resonance images. In the apparatus, spin excitation is effected at all the phases including those where nuclear magnetic resonance images are obtained and those where nuclear magnetic resonance images are not obtained, so that all the phases have the same longitudinal relaxation time after spin excitation. Therefore, nuclear magnetic resonance signals free from variations of the longitudinal relaxation time can be obtained to provide clear nuclear magnetic resonance images at anyone of the plurality of phases.
19 Citations
15 Claims
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1. A magnetic resonance examining apparatus of heart beat synchronous type for imaging multiphase images in synchronism with a heart beat of a subject, said apparatus comprising:
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means for detecting a heart beat waveform of the subject; means for generating a synchronizing signal synchronous with the heart beat waveform detected by said detecting means; means for measuring a repetition period of said heart beat waveform on the basis of the synchronizing signal applied from said synchronizing signal generating means; input means for inputting a previously stored setting of a repetition time for spin excitation of the subject; means responsive to said measuring means and said input means for computing a corrected repetition time close to said spin excitation repetition time on the basis of data of said heart beam waveform repetition period supplied from said measuring means and the setting of said spin excitation repetition time supplied from said input means, said corrected repetition time having a value which, when multiplied by a factor of N (N;
an integer), becomes equal to that of said heart beat waveform repetition period;means for setting a plurality of imaging phases so as to form nuclear magnetic resonance images; and means for effecting spin excitation of the subject according to the corrected repetition period; means for setting a plurality of imaging phases so as to form nuclear magnetic resonance images; and means for effecting spin excitation of the subject according to the corrected repetition time computed by said corrected repetition time computing means and acquiring a nuclear magnetic resonance signal for each of the imaging phases set by said imaging phase setting means. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A magnetic resonance examining apparatus of heart beat synchronous type for imaging multiphase images in synchronism with a heart beat of a subject, said apparatus comprising:
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means for detecting a heart beat waveform of the subject; means for generating a synchronizing signal synchronous with the heart beat waveform detected by said detecting means; means for measuring a repetition period of said heart beat waveform on the basis of the synchronizing signal applied from said synchronizing signal generating means; input means for inputting a previously stored setting of a repetition time for spin excitation of the subject and a previously stored setting of the number of phase images; means responsive to said measuring means and said input means for computing a number of phase images that can be imaged on the basis of data of said heart beat repetition period supplied from said measuring means and the setting of said spin excitation repetition time supplied from said input means; means for computing a corrected repetition time close to said spin excitation repetition time on the basis of the computed number of phase images computed by said phase image number computing means and the setting of said spin excitation repetition time supplied from said input means; means for comparing the computed number of phase images computed by said phase image number computing means with the setting of the number of phase images supplied from said input means so as to confirm whether or not the computed number of phase images is equal to or larger than the setting of the number of phase images supplied from said input means; and means for effecting spin excitation of the subject according to the corrected repetition time computed by said corrected repetition time computing means and acquiring a nuclear magnetic resonance signal for each of the imaging phases stored in said input means, only when said comparing means confirms that the computed number of phase images is equal to or larger than the set number of phase images set in said input means. - View Dependent Claims (12, 13, 15)
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14. A magnetic resonance examining apparatus of heart beat synchronous type for imaging multiphase image in synchronism with a heart beat of a subject, said apparatus comprising:
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means for detecting a heart beam waveform of the subject; means for generating a synchronizing signal synchronous with the heart beat waveform detected by said detecting means; means for measuring a repetition period of said heart beat waveform on the basis of the synchronizing signal applied from said synchronizing signal generating means; input means for inputting a previously stored setting of the number of phase images to be imaged; means responsive to said measuring means and said input means for computing a repetition time for spin excitation of the subject on the basis of data of said heart beat waveform repetition period supplied from said measuring means and the setting of the number of phase images supplied from said input means; means for setting a plurality of imaging phases so as to form nuclear magnetic resonance images; and means for effecting spin excitation of the subject according to the repetition time computed by said spin excitation repetition time computing means and acquiring a nuclear magnetic resonance signal for each of the imaging phases set by said imaging phase setting means.
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Specification