System for optimized low power MR imaging

Patent metadata

Field	Value
Publication number	US-10012709-B2
Application number	US-201313958654-A
Country	US
Kind code	B2
Filing date	Aug 5, 2013
Priority date	Aug 6, 2012
Publication date	Jul 3, 2018
Grant date	Jul 3, 2018

Abstract

A system acquires MR imaging data of a portion of patient anatomy associated with proton spin lattice relaxation time in a rotating frame using an RF (Radio Frequency) signal generator configured to generate RF excitation pulses and a magnetic field gradient generator configured to generate anatomical volume select magnetic field gradients for phase encoding and readout RF data acquisition. The RF signal generator and the gradient generator are configured to provide a rotating frame preparation pulse sequence comprising at least one of, (a) a T1 spin lattice relaxation in a rotating frame (T1ρ) preparation pulse sequence of adiabatic pulses comprising modulated RF pulses and modulated magnetic field gradients for slice selection and (b) a T2 spin-spin relaxation in a rotating frame (T2ρ) preparation pulse sequence of adiabatic pulses comprising modulated RF pulses and modulated magnetic field gradients for slice selection.

First claim

What is claimed:

1. A system for acquiring MR imaging data of a portion of patient anatomy associated with proton spin lattice relaxation time in a rotating frame, comprising:
an RF (Radio Frequency) signal generator configured to generate RF excitation pulses in an anatomy and enabling subsequent acquisition of associated RF echo data; and
a magnetic field gradient generator configured to generate anatomical volume select magnetic field gradients for phase encoding and readout RF data acquisition in a three dimensional (3D) anatomical volume,
wherein said RF signal generator and said gradient generator provide a rotating frame preparation pulse sequence comprising at least one of:
(a) a T1 spin lattice relaxation in a rotating frame (T1ρ) preparation pulse sequence of adiabatic pulses comprising modulated RF pulses and modulated magnetic field gradients for slice selection applied simultaneously with the modulated RF pulses; or
(b) a T2 spin-spin relaxation in a rotating frame (T2ρ) preparation pulse sequence of adiabatic pulses comprising modulated RF pulses and modulated magnetic field gradients for slice selection applied simultaneously with the modulated RF pulses;
wherein said modulated RF pulses and modulated magnetic field gradients for slice selection comprise a Gradient Offset Independent Adiabaticity pulse with Wurst modulation (GOIA-W).

2. A system according to claim 1 , wherein
said RF signal generator and said gradient generator use a readout gradient for RF data acquisition, and
said rotating frame preparation pulse sequence of adiabatic pulses and readout RF data acquisition enable acquisition of a plurality of image slices within a single imaging scan.

3. A system according to claim 2 , wherein
said single imaging scan comprises a programmed acquisition of MR image data without user interaction in controlling an MRI scanner.

4. A system according to claim 2 , wherein
said rotating frame preparation pulse sequence of adiabatic pulses and readout RF data acquisition enable acquisition of said plurality of image slices comprising at least one of: (a) 20 slices with (echo planar imaging) EPI based data acquisition; or (b) 128 slices with 3D TFL (turbo-FLASH) based data acquisition.

5. A system according to claim 4 , wherein
said rotating frame preparation pulse sequence of adiabatic pulses and readout RF data acquisition enable acquisition of said plurality of image slices comprising at least one of: (a) 20 slices with EPI based data acquisition within 1.5 minutes; or (b) 128 slices with 3D TFL (turbo-FLASH) based data acquisition within 7.21 minutes.

6. A system according to claim 2 , wherein
said rotating frame preparation pulse sequence of adiabatic pulses and readout RF data acquisition enable acquisition of said plurality of image slices with a Specific Absorption Rate enabling accelerated image acquisition of said plurality of image slices within a single scan.

7. A system according to claim 1 , wherein
said T1ρ spin lattice relaxation is obtained when proton spin magnetization is locked along the direction of an effective magnetic field in response to RF pulse amplitude and RF offset modulation.

8. A system according to claim 1 , wherein
said T2ρ spin-spin relaxation is obtained in response to proton spin magnetization being perpendicular and precessing around the direction of an effective magnetic field resulting from an RF pulse amplitude and RF offset modulation.

9. A system according to claim 1 , wherein a modulation function is;

RF
⁡

(
t
)

=

RF
max

⁡

(

1
-



sin
⁡

(

π
2

⁢

(

2
⁢
t

T
p

-
1

)

)



n

)

G
⁡

(
t
)

=

G
max

⁡

(

(

1
-
f

)

+

f
⁢



sin
⁡

(

π
2

⁢

(

2
⁢
t

T
p

-
1

)

)



m

)

where Tp is the pulse dura

Assignees

• Andronesi Ovidiu
• Rosen Bruce
• Caravan Peter
• Bhat Himanshu
• Massachusetts Gen Hospital
• Siemens Healthcare Gmbh

Inventors

• Andronesi Ovidiu
• Rosen Bruce
• Caravan Peter
• Bhat Himanshu

Classifications

• A61B5/055

  involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging · CPC title

• G01R33/5617

  using RF refocusing, e.g. RARE · CPC title

• G01R33/5616

  using gradient refocusing, e.g. EPI · CPC title

• G01R33/5602 Primary

  by filtering or weighting based on different relaxation times within the sample, e.g. T1 weighting using an inversion pulse · CPC title

• G01R33/36 Primary

  Electrical details, e.g. matching or coupling of the coil to the receiver · CPC title