US 11,860,258 B2
Methods and systems for Maxwell compensation for spin-echo train imaging
John P. Mugler, III, Charlottesville, VA (US); Craig H. Meyer, Charlottesville, VA (US); Adrienne Campbell, Washington, DC (US); Rajiv Ramasawmy, Bethesda, MD (US); Josef Pfeuffer, Erlangen (DE); Zhixing Wang, Charlottesville, VA (US); and Xue Feng, Zion Crossroads, VA (US)
Assigned to UNIVERSITY OF VIRGINIA PATENT FOUNDATION, Charlottesville, VA (US); SIEMENS HEALTHCARE GMBH, Erlangen (DE); and THE UNITED STATES OF AMERICA, AS REPRESENTED BY THE SECRETARY, DEPARTMENT OF HEALTH AND HUMAN SERVICES, Bethesda, MD (US)
Filed by University of Virginia Patent Foundation, Charlottesville, VA (US); THE UNITED STATES OF AMERICA, AS REPRESENTED BY THE SECRETARY DEPARTMENT OF HEALTH AND HUMAN SERVICES, Bethesda, MD (US); and Siemens Healthcare GMBH, Erlangen (DE)
Filed on Apr. 28, 2022, as Appl. No. 17/732,155.
Claims priority of provisional application 63/180,807, filed on Apr. 28, 2021.
Claims priority of provisional application 63/318,156, filed on Mar. 9, 2022.
Prior Publication US 2022/0357416 A1, Nov. 10, 2022
Int. Cl. G01R 33/565 (2006.01); G01R 33/561 (2006.01)
CPC G01R 33/56581 (2013.01) [G01R 33/5618 (2013.01)] 16 Claims
OG exemplary drawing
 
1. A method for turbo spin-echo (TSE) imaging of a subject, the method implemented by one or more computing devices and comprising:
generating a radio frequency (RF) excitation pulse to produce transverse magnetization that generates a nuclear magnetic resonance (NMR) signal and a series of RF refocusing pulses to produce a corresponding series of NMR spin-echo signals;
modifying an original encoding gradient waveform comprising a non-rectilinear encoding trajectory by:
introducing at least one zero zeroth-moment waveform segment comprising two bipolar pairs at one or both ends of the original encoding gradient waveform; and
reversing a polarity of one of the two bipolar pairs for one of a first gradient axis or a second gradient axis different from the first gradient axis;
generating during an interval adjacent to each of the series of RF refocusing pulses a first gradient pulse and a second gradient pulse, wherein:
at least one of the first or second gradient pulses is generated according to the modified gradient waveform; and
the first and second gradient pulses encode the NMR spin-echo signals corresponding to the first gradient axis and the second gradient axis, respectively; and
constructing an image from generated digitized samples of the NMR spin-echo signals obtained based on the encoding.