IP Library Granted Patent US 10,416,267
Granted Patent B2
US 10,416,267 · App. 15/401,749 · Granted Sep 17, 2019

Apparatus and method for calibration of time origin of an RF pulse in MRI data acquisition systems

View Patent ↗
Loading inventors, assignments & file history…
Monitor This Case
Get email alerts when status or documents change.
Order Certified Copies
Most orders are placed with the USPTO same day — all within 24 business hours.
Order via The Patent Place →
Pre-filled with this patent's details
Quick Facts
Patent No.
US 10,416,267
App. No.
15/401,749
Filed
Jan 9, 2017
Granted
Sep 17, 2019
Kind
B2
Art Unit
2852
USPC
324/309
Abstract

An apparatus and method are disclosed for determining a time origin of an input RF pulse of a plurality of input RF pulses. The method includes generating an RF echo based on the plurality of input RF pulses, a time-duration between the input RF pulses being controllable in order to determine a time instance corresponding to an ideal position of the RF echo. The method further includes acquiring a data signal corresponding to a scan of a subject, and computing a time-difference between a measured peak of the acquired data signal and the time instance corresponding to the ideal position of the RF echo, the computed time difference corresponding to a measure of a time-shift of an effective magnetic center of the input RF pulse.

Claims (43)

1. A method for determining a time origin of an input RF pulse of a plurality of input RF pulses, the method comprising:

generating, by circuitry, an RF echo based on the plurality of input RF pulses, a time-duration between the input RF pulses being controllable in order to determine a time instance corresponding to an ideal position of the RF echo;

computing a time-difference between a time corresponding to a measured peak of an acquired data signal and the time instance corresponding to the ideal position of the RF echo, the computed time difference corresponding to a measure of a time-shift of the time origin of the input RF pulse;

repeating, for a predetermined number of iterations, the steps of generating the RF echo based acquiring the data signal;

computing, for each subsequent iteration, a time-difference between a measured peak of the data signal that is subsequently acquired and an ideal position of a subsequent RF echo; and

computing the measure of the time-shift of the time origin of the input RF pulse based on the computed subsequent time-differences.

2. The method of claim 1 , wherein the plurality of input RF pulses have a substantially similar time-duration, amplitude, waveform shape, and flip-angle.

3. The method of claim 1 , further comprising:

applying a gradient waveform having a uniform amplitude for an amount of time lasting from a time of input of the plurality of input RF pulses to a time of acquisition of the data signal.

4. The method of claim 1 , wherein the plurality of input RF pulses is a pair of input RF pulses.

5. The method of claim 1 , further comprising:

incrementing, by a predetermined amount by the circuitry, a time duration between the input RF pulses of the subsequent iterations.

6. A method for determining a time origin of an input RF pulse of a plurality of input RF pulses, the method comprising:

generating, by circuitry, an RF echo based on the plurality of input RF pulses, a time-duration between the input RF pulses being controllable in order to determine a time instance corresponding to an ideal position of the RF echo; and

computing a time-difference between a time corresponding to a measured peak of an acquired data signal and the time instance corresponding to the ideal position of the RF echo, the computed time difference corresponding to a measure of a time-shift of the time origin of the input RF pulse, wherein

the plurality of input RF pulses includes at least three input RF pulses.

7. A method for determining a time origin of an input RF pulse of a plurality of input RF pulses, the method comprising:

generating, by circuitry, an RF echo based on the plurality of input RF pulses, a time-duration between the input RF pulses being controllable in order to determine a time instance corresponding to an ideal position of the RF echo;

computing a time-difference between a time corresponding to a measured peak of an acquired data signal and the time instance corresponding to the ideal position of the RF echo, the computed time difference corresponding to a measure of a time-shift of the time origin of the input RF pulse;

repeating, for a predetermined number of iterations, the steps of generating the RF echo based acquiring the data signal; and

generating, by the circuitry, a line based on data corresponding to occurrences of the subsequent peaks of the acquired data signals, and associated time-shifts in the occurrences of the subsequent peaks, the time-shifts corresponding to the incremented time durations between the input RF pulses of the subsequent iterations.

8. A device for determining a time origin of an input RF pulse of a plurality of input RF pulses, the device comprising:

circuitry configured to

generate an RF echo based on the plurality of input RF pulses, a time-duration between the input RF pulses being controllable in order to determine a time instance corresponding to an ideal position of the RF echo,

compute a time-difference between a time corresponding to a measured peak of an acquired data signal and the time instance corresponding to the ideal position of the RF echo, the computed time difference corresponding to a measure of a time-shift of the time origin of the input RF pulse,

repeat, for a predetermined number of iterations, the steps of generating the RF echo based acquiring the data signal,

compute for each subsequent iteration, a time-difference between a measured peak of the subsequently acquired data signal and an ideal position of a subsequent RF echo, and

compute the measure of the time-shift of the time origin of the input RF pulse based on the computed subsequent time-differences.

9. The device of claim 8 , wherein the circuitry is configured to generate the RF echo based on the plurality of input RF pulses, which have a substantially similar time-duration, amplitude, waveform shape, and flip-angle.

10. The device of claim 8 , wherein the circuitry is further configured to apply a gradient waveform having a uniform amplitude for an amount of time lasting from a time of input of the plurality of input RF pulses to a time of acquisition of the data signal.

11. The device of claim 10 , wherein the circuitry is configured to generate the RF echo based on the plurality of input RF pulses, which is a pair of input RF pulses.

12. The device of claim 8 , wherein the circuitry is further configured to:

increment by a predetermined amount, a time duration between the input RF pulses of the subsequent iterations.

13. A device for determining a time origin of an input RF pulse of a plurality of input RF pulses, the device comprising:

circuitry configured to

generate an RF echo based on the plurality of input RF pulses, a time-duration between the input RF pulses being controllable in order to determine a time instance corresponding to an ideal position of the RF echo,

compute a time-difference between a time corresponding to a measured peak of an acquired data signal and the time instance corresponding to the ideal position of the RF echo, the computed time difference corresponding to a measure of a time-shift of the time origin of the input RF pulse, wherein the circuitry is further configured to repeat the generating and the acquiring steps for a predetermined number of iterations, and

generate a line based on data corresponding to occurrences of the subsequent peaks of the acquired data signals, and associated time-shifts in the occurrences of the subsequent peaks, the time-shifts corresponding to the incremented time durations between the input RF pulses of the subsequent iterations.

14. A device for determining a time origin of an input RF pulse of a plurality of input RF pulses, the device comprising:

circuitry configured to

generate an RF echo based on the plurality of input RF pulses, a time-duration between the input RF pulses being controllable in order to determine a time instance corresponding to an ideal position of the RF echo,

compute a time-difference between a time corresponding to a measured peak of an acquired data signal and the time instance corresponding to the ideal position of the RF echo, the computed time difference corresponding to a measure of a time-shift of the time origin of the input RF pulse, and

generate the RF echo based on the plurality of input RF pulses, which includes at least three input RF pulses.

Assignments (2)
CHANGE OF NAME Recorded Jul 1, 2019
From: TOSHIBA MEDICAL SYSTEMS CORPORATION
To: CANON MEDICAL SYSTEMS CORPORATION
Reel/Frame 049637/0787 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jan 9, 2017
From: WHEATON, ANDREW JAMES; THOMPSON, MICHAEL R.
To: TOSHIBA MEDICAL SYSTEMS CORPORATION
Reel/Frame 040904/0137 →