High speed NMR imaging method and apparatus

Claim 3

A method according to claim 1 wherein the NMR pulse sequences are applied at intervals of about 8-20 milliseconds.

Claim 4

A method according to claim 1 wherein said predetermined plurality of applications of the NMR pulse sequence comprises 16-128 pulses having 16-128 corresponding phase encodings.

Claim 5

A method according to claim 1 wherein said application of one or more NMR pulse sequences comprises 1-10 pulses having 1-10 corresponding phase encodings.

Claim 7

A method according to claim 1 wherein each of said predetermined plurality of applications of a short repetition time NMR pulse sequence corresponds to one of said corresponding plurality of phase encodings.

Claim 8

A method according to claim 1 wherein each of said predetermined plurality of applications of a short repetition time NMR pulse sequence corresponds to two or more of said corresponding plurality of phase encodings.

Claim 9

A method according to claim 1 including concurrently and interactively adjusting the volume or slice being irradiated, measured, and imaged by altering selectable gradient parameters.

Claim 10

A method according to claim 8 wherein said selectable gradient parameters comprise slice selection, phase encoding and frequency encoding.

Claim 11

A method according to claim 9 wherein the adjustments which may be made to the image include angulation of an image slice.

Claim 12

A method according to claim 1 including concurrently and interactively adjusting image features by altering the radiofrequency modulation and amplitude, the repetition time (TR), and the echo time (TE) either individually or in any desired combination thereof.

Claim 15

A method according to claim 12 wherein the NMR pulse sequences are applied at intervals of about 10-16 milliseconds.

Claim 16

A method according to claim 12 wherein said predetermined plurality of applications of the NMR pulse sequence comprises 16-128 pulses having 16-128 corresponding phase encodings.

Claim 17

A method according to claim 12 wherein said application of one or more NMR pulse sequences comprises 1-10 pulses having 1-10 corresponding phase encodings.

Claim 18

A method according to claim 13, 14 or 15 wherein the image is updated at intervals of about 10-500 milliseconds.

Claim 19

A method according to claim 12 wherein said selectable gradient parameters comprise slice selection, phase encoding and frequency encoding.

Claim 20

A method according to claim 17 wherein the adjustments which may be made to the image include angulation.

Claim 21

A method according to claim 12 including concurrently and interactively adjusting image features by altering the radiofrequency modulation and amplitude, the repetition time (T)), and the echo time (TE) either individually or in any desired combination thereof.

Claim 22

A high speed NMR imaging apparatus for constructing and displaying near real time images of a body portion of interest and which are derived from NMR measurements, said apparatus comprising: means for performing NMR measurements on a body using a predetermined pulse sequence that generates signals; means for subjecting said signals derived from said pulse sequences to a Fast Fourier Transform; buffer memory means for storing said signals with the most recently acquired signals at the top of the memory; means for repetitively providing a video synchronization pulse at predetermined intervals; means for reading a predetermined one or more of the most recently acquired signals from said buffer memory means upon prompting by said video synchronization pulse, and forming for each a difference signal by subtracting therefrom the previous one or more signals corresponding thereto, said previous signals also having been stored in said buffer memory means; means for forming an image contribution for each of said difference signals by multiplication of each of said difference signals by a complex exponential function of appropriate frequency; image storage memory means for containing an existing total current image; means for adding said image contributions to said existing total current image contained in said image storage memory means; and means associated with said image storage memory means for forming and displaying a continuously updated image of the body portion of interest.

Claim 23

A high speed NMR imaging apparatus for constructing and displaying near real time images of a body portion of interest and which are derived from NMR measurements, said apparatus comprising: means for performing NMR measurements on a body using a predetermined pulse sequence that generates signals; means for subjecting said signals derived from said pulse sequences to a Fast Fourier Transform; buffer memory means for storing said signals with the most recently acquired signals at the top of the memory; means for repetitively providing a video synchronization pulse at predetermined intervals; means for reading a predetermined one or more of the most recently acquired signals from said buffer memory means upon prompting by said video synchronization pulse, and forming for each a difference signal by subtracting therefrom the previous one or more signals corresponding thereto, said previous signals also having been stored in said buffer memory means; means for forming an image contribution for each of said difference signals by multiplication of each of said difference signals by a complex exponential function of appropriate frequency; image storage memory means for containing an existing total current image; means for adding said image contributions to said existing total current image contained in said image storage memory means; and means associated with said image storage memory means for forming and displaying a continuously updated image of the body portion of interest.

Claim 24

A high speed NMR imaging apparatus according to claim 20 wherein the time interval of each pulse sequence is about 10 milliseconds, the time interval of the Fourier Transformation of data from each pulse sequence is about 5 milliseconds, and the time interval between each video synchronization pulse is about 33 milliseconds.

Claim 25

A high speed NMR imaging apparatus according to claim 21 wherein said image of the body portion is updated about every 1/30 second.

Claim 26

A high speed NMR imaging apparatus according to claim 20 comprising a reading means and a corresponding image forming means for each of said recently acquired signals.

Claim 27

A high speed NMR imaging apparatus according to claim 20 including means for interactive control of the image being constructed and displayed in order to obtain a desired oblique angulation of the image, said interactive control means comprising control means for selectively adjusting pulse sequence gradient parameters including slice selection, phase encoding, and frequency encoding, and computer means electrically connected to said control means for computing adjustments to be made to said gradient parameters to effect the desired change in oblique angulation of the image being formed and displayed.

Claim 28

A high speed NMR imaging apparatus for constructing and displaying near real time images of a body portion of interest and which are derived from NMR measurements, said apparatus comprising: means for performing NMR measurements on a body using a predetermined pulse sequence that generates signals; means for subjecting said signals derived from said pulse sequences to a Fast Fourier Transform; buffer memory means for storing said signals with the most recently acquired signals at the top of the memory; means for repetitively providing a video synchronization pulse at predetermined intervals; means for reading a predetermined one or more of the most recently acquired signals form said buffer memory means upon prompting by said video synchronization pulse, and forming for each a difference signal by subtracting therefrom the previous one or more signals corresponding thereto, said previous signals also having been stored in said buffer memory means; means for forming an image contribution for each of said difference signals by multiplication of each of said difference signals by a complex exponential function of appropriate frequency; image storage memory means for containing an existing total current image; means for adding said image contributions to said existing total current image contained in said image storage memory means; means associated with said image storage memory means for forming and displaying a continuously updated image of the body portion of interest; and means for interactive control of the image being formed and displayed in order to obtain a desired oblique angulation of the image, said interactive control means comprising control means for selectively adjusting pulse sequence gradient parameters including slice selection, phase encoding and frequency encoding, and computer means electrically connected to said control means for computing adjustments to be made to said gradient parameters to effect the desired change in oblique angulation of the image being formed and displayed.

Claim 29

A high speed NMR imaging apparatus for constructing and displaying near real time images of a body portion of interest and which are derived from NMR measurements, said apparatus comprising: means for performing NMR measurements on a body using a predetermined pulse sequence that generates signals; means for subjecting said signals derived from said pulse sequences to a Fast Fourier Transform; buffer memory means for storing said signals with the most recently acquired signals at the top of the memory; means for repetitively providing a video synchronization pulse at predetermined intervals; means for reading a predetermined one or more of the most recently acquired signals form said buffer memory means upon prompting by said video synchronization pulse, and forming for each a difference signal by subtracting therefrom the previous one or more signals corresponding thereto, said previous signals also having been stored in said buffer memory means; means for forming an image contribution for each of said difference signals by multiplication of each of said difference signals by a complex exponential function of appropriate frequency; image storage memory means for containing an existing total current image; means for adding said image contributions to said existing total current image contained in said image storage memory means; means associated with said image storage memory means for forming and displaying a continuously updated image of the body portion of interest; and means for interactive control of the image being formed and displayed in order to obtain a desired oblique angulation of the image, said interactive control means comprising control means for selectively adjusting pulse sequence gradient parameters including slice selection, phase encoding and frequency encoding, and computer means electrically connected to said control means for computing adjustments to be made to said gradient parameters to effect the desired change in oblique angulation of the image being formed and displayed.

Claim 30

A high speed NMR imaging apparatus according to claim 25 wherein said continuously updated image is formed and displayed concurrently with adjustment of said control means and the oblique angulation of the image is substantially instantaneously changed to a new oblique angulation corresponding to the adjustment of said control means.