Three-echo balanced steady state free precession impulse sequence imaging method

Abstract

The invention discloses a three-echo balanced steady state free precession impulse sequence imaging method and relates to the field of magnetic resonance imaging. The method comprises the following steps of: step 1, three-echo balanced steady-state free precession sequence imaging data acquisition: acquiring three echoes with different TE time, namely a first echo, a second echo and a third echo,under the condition that repetition time is not changed; step 2, three-echo balanced steady-state free precession sequence image reconstruction; and step 3, K-space trajectory correction on the imagereconstruction in the step 2. According to the method, three three-dimensional images can be obtained after radial sampling of a plurality of TRs, tissue information which cannot be displayed by a traditional balanced steady-state free precession impulse sequence can be obtained by utilizing the images of the three echoes, the signal-to-noise ratio of the images can be increased, and quantitativemeasurement of tissue attenuation parameters can be obtained. Three-dimensional imaging of bones, tendons, lungs and various soft tissues is obtained through the method; and the method is suitable forattenuation correction of positron emission imaging.

Description

technical field [0001] The invention relates to the field of magnetic resonance imaging, in particular to a three-echo balanced steady-state free-precession pulse sequence imaging method. Background technique [0002] In the traditional balanced steady-state free-precession pulse sequence, only one echo is collected in a repetition time (repetition time, TR). After multiple TR samples, an image can be obtained. [0003] Balanced steady state free precession sequence (balanced steady state free precession, bSSFP) is a kind of coherent steady state gradient echo pulse sequence (gradient recalled acquisition in the steady state, GRASS). The main feature of the bSSFP sequence is that the gradient waveform is completely symmetrical within one TR, and the net gradient areas in the three directions are zero. And the sequence is often excited with alternating phase radio frequency pulses. In addition, the resulting image contrast of this sequence is T2 / T1 weighted, which provides...

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Problems solved by technology

[0007] In view of the above-mentioned defects of the prior art, the technical problem to be solved by the present invention is to invent a three-dimensional radial sampling magnetic resonance imaging method using a three-echo balanced steady-state free precession pulse sequence without increasing the imaging time , to obtain a variety of tissue signals that cannot be obtained by conventional equilibrium steady-state free precession pulse sequences, such as bone, tendon, and lung signals

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