MAGNETIC RESONANCE APPARATUS AND METHOD FOR OBTAINING MEASUREMENT SIGNALS IN SPIN ECHO-BASED IMAGING
First Claim
1. A method for obtaining raw data for reconstructing a magnetic resonance (MR) image therefrom, said method comprising:
- from a computer, operating an MR data acquisition scanner so as to apply a static magnetic field in a positive z-direction in the MR data acquisition scanner, which produces magnetization in the positive z-direction in an object situated in the MR data acquisition scanner;
from said computer, operating said MR data acquisition scanner so as to execute a spin-echo-based MR data acquisition sequence, including applying an excitation pulse that tilts said magnetization by a predetermined angle;
in said spin-echo-based sequence, applying a refocusing pulse;
from said computer, operating said MR data acquisition scanner to additionally radiate an RF pulse at a time of an echo caused by said excitation and refocusing pulses, which deflects said magnetization in a negative z-direction by a flip angle; and
in said computer, specifying a repetition time of said excitation pulse, and setting said flip angle, for the specified repetition time, so as to produce a predetermined contrast for two predetermined tissue types of the subject.
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Accused Products
Abstract
In order to optimize magnetic resonance (MR) images in spin echo-based imaging, MR raw data are acquired by applying a static magnetic field, an excitation pulse, a refocusing pulse, and an RF pulse at the same time point as an echo elicited by the pulses with the result that the magnetization in the negative z-direction is deflected by a flip angle. The flip angle is selected such that, given a specified repetition time of the excitation pulse, a predetermined contrast is provided for two specified tissue types of the subject to be imaged. An MR image is reconstructed from the acquired MR raw data.
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Citations
13 Claims
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1. A method for obtaining raw data for reconstructing a magnetic resonance (MR) image therefrom, said method comprising:
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from a computer, operating an MR data acquisition scanner so as to apply a static magnetic field in a positive z-direction in the MR data acquisition scanner, which produces magnetization in the positive z-direction in an object situated in the MR data acquisition scanner; from said computer, operating said MR data acquisition scanner so as to execute a spin-echo-based MR data acquisition sequence, including applying an excitation pulse that tilts said magnetization by a predetermined angle; in said spin-echo-based sequence, applying a refocusing pulse; from said computer, operating said MR data acquisition scanner to additionally radiate an RF pulse at a time of an echo caused by said excitation and refocusing pulses, which deflects said magnetization in a negative z-direction by a flip angle; and in said computer, specifying a repetition time of said excitation pulse, and setting said flip angle, for the specified repetition time, so as to produce a predetermined contrast for two predetermined tissue types of the subject. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A magnetic resonance (MR) apparatus for obtaining MR raw data for reconstructing an MR image therefrom, said MR apparatus comprising:
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an MR data acquisition scanner; a computer configured to operate said MR data acquisition scanner so as to apply a static magnetic field in a positive z-direction in the MR data acquisition scanner, which produces magnetization in the positive z-direction in an object situated in the MR data acquisition scanner; said computer being configured to operate said MR data acquisition scanner so as to execute a spin-echo-based MR data acquisition sequence, including applying an excitation pulse that tilts said magnetization by a predetermined angle; said computer being configured to operate said MR data acquisition scanner in said spin-echo-based sequence so as to apply a refocusing pulse; said computer being configured to operate said MR data acquisition scanner so as to additionally radiate an RF pulse at a time of an echo caused by said excitation and refocusing pulses, which deflects said magnetization in a negative z-direction by a flip angle; and said computer being configured to specify a repetition time of said excitation pulse, and to set said flip angle, for the specified repetition time, so as to produce a predetermined contrast for two predetermined tissue types of the subject.
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Specification