Multi-parameter quantitative imaging method and device, nuclear magnetic resonance equipment and storage medium

Abstract

The invention discloses a multi-parameter quantitative imaging method and device, nuclear magnetic resonance equipment and a storage medium, the multi-parameter quantitative imaging method is applied to the nuclear magnetic resonance equipment, and the nuclear magnetic resonance equipment comprises a T2 preparation sequence module and a variable flip angle multi-echo gradient echo sequence module connected with the T2 preparation sequence module. Comprising the steps that equivalent echo time is controlled through a T2 preparation sequence module, a flip angle is controlled through a variable flip angle multi-echo gradient echo sequence module, a target object is scanned, and a multi-parameter echo signal is obtained; and performing imaging processing on the multi-parameter echo signal based on the image demand configuration information to obtain a required multi-parameter quantitative image. According to the invention, T2 preparation and a variable flip angle technology are combined, and a multi-parameter echo signal can be obtained through one-time scanning, so that a multi-parameter quantitative image is obtained, and the parameter imaging efficiency is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of nuclear magnetic resonance, quantitative parameter imaging, and the like, and in particular to a multi-parameter quantitative imaging method and device, a nuclear magnetic resonance apparatus, and a storage medium. BACKGROUND

[0002] Magnetic resonance imaging (MRI) is one of important imaging methods in modern medical imaging and is widely used in clinical medical imaging assisted diagnosis. In clinical application, a parameter image obtained based on a magnetic resonance signal and experience of a clinician are usually used to identify a lesion, so as to diagnose and analyze a disease. In the related art, a parameter quantitative image can only obtain one kind of parameter quantitative image through single sequence scanning, and cannot simultaneously obtain quantitative images of multiple different parameters. SUMMARY

[0003] To this end, the purpose of the embodiments of the present application is to provide a multi-parameter quantitative imaging method and device, a nuclear magnetic resonance apparatus, a storage medium, and a computer program product. The present application combines T2 preparation and variable flip angle technology, and can obtain multi-parameter echo signals through one scan, obtain multi-parameter quantitative images after imaging processing, and improve parameter imaging efficiency.

[0004] The embodiments of the present application provide a multi-parameter quantitative imaging method. The method is applied to a nuclear magnetic resonance apparatus, the nuclear magnetic resonance apparatus includes a T2 preparation sequence module and a variable flip angle multi-echo gradient echo sequence module connected with the T2 preparation sequence module, and the method includes: controlling an equivalent echo time through the T2 preparation sequence module and controlling a flip angle through the variable flip angle multi-echo gradient echo sequence module, and scanning a target object to obtain multi-parameter echo signals, wherein the multi-parameter echo signals include multiple groups of multi-echo gradient signals corresponding to multiple flip angles at the same equivalent echo time and multiple groups of multi-echo gradient signals corresponding to the same flip angle at multiple equivalent echo times; and performing imaging processing on the multi-parameter echo signals based on image requirement configuration information to obtain required multi-parameter quantitative images.

[0005] Exemplarily, the T2 preparation sequence module includes a first tilt pulse, a first refocusing pulse, a second refocusing pulse, and a second tilt pulse connected in sequence, the first tilt pulse and the second tilt pulse are used for downward tilting and upward tilting processing of a magnetization vector, and the first refocusing pulse and the second refocusing pulse are used for refocusing processing of phases of transverse plane spin protons, wherein the equivalent echo time is a time interval between the first tilt pulse and the second tilt pulse.

[0006] Exemplarily, the imaging processing of the multi-parameter echo signal based on the image requirement configuration information to obtain the required multi-parameter quantitative image includes: when the image requirement configuration information indicates that the required multi-parameter quantitative image includes a longitudinal relaxation T1 parameter image, imaging processing is performed on the echo signals of the same echo time corresponding to multiple flip angles under the same equivalent echo time to obtain the longitudinal relaxation T1 parameter image.

[0007] Exemplarily, the imaging processing of the multi-parameter echo signal based on the image requirement configuration information to obtain the required multi-parameter quantitative image includes: when the image requirement configuration information indicates that the required multi-parameter quantitative image includes a transverse relaxation T2 parameter image, imaging processing is performed on the echo signal of the same echo time corresponding to the same flip angle under multiple equivalent echo times to obtain a transverse relaxation T2 parameter image.

[0008] Exemplarily, the imaging process is performed on the multi-parameter echo signal based on the image requirement configuration information to obtain the required multi-parameter quantitative image, including: when the image requirement configuration information indicates that the required multi-parameter quantitative image includes effective transverse relaxation T2 * and / or relaxation rate R2 * In the case of parametric imaging, imaging processing is performed on at least two target echo signals corresponding to any flip angle at any equivalent echo time to obtain the effective transverse relaxation T2 * and / or relaxation rate R2 * A parametric image, wherein the echo times of the at least two target echo signals are different.

[0009] For example, the multi-parameter quantitative image includes a longitudinal relaxation T1 parameter image, a transverse relaxation T2 parameter image, an effective transverse relaxation T2 * Parameter image, relaxation rate R2 * At least one of a parameter image, a radio frequency magnetic field B1 parameter image, a magnetic susceptibility QSM parameter image, a proton density PD parameter image, and a weighted image.

[0010] Exemplarily, the variable flip angle multi-echo gradient echo sequence module includes at least one of an SPGR sequence multi-echo gradient echo sequence module and a dual TR gradient echo sequence module.

[0011] Another embodiment of the present application provides a multi-parameter quantitative imaging device, which is applied to a nuclear magnetic resonance device including a T2 preparation sequence module and a variable flip angle multi-echo gradient echo sequence module connected to the T2 preparation sequence module, and includes: a scanning module configured to control an equivalent echo time by the T2 preparation sequence module and a flip angle by the variable flip angle multi-echo gradient echo sequence module, and to scan a target object to obtain a multi-parameter echo signal, wherein the multi-parameter echo signal includes a plurality of sets of multi-echo gradient signals corresponding to a plurality of flip angles at the same equivalent echo time and a plurality of sets of multi-echo gradient signals corresponding to the same flip angle at a plurality of equivalent echo times; and a processing module configured to perform imaging processing on the multi-parameter echo signal based on image requirement configuration information to obtain a required multi-parameter quantitative image.

[0012] Another embodiment of the present application provides a nuclear magnetic resonance device including a T2 preparation sequence module and a variable flip angle multi-echo gradient echo sequence module connected to the T2 preparation sequence module, which is configured to implement the steps of the method described above.

[0013] Another embodiment of the present application provides a computer readable storage medium having a computer program stored thereon, which is configured to implement the steps of the method of any of the embodiments described above when executed by a processor.

[0014] Another embodiment of the present application provides a computer program product including instructions, which are configured to enable a computer device to perform the steps of the method of any of the embodiments described above when executed by a processor of the computer device.

[0015] In the embodiments described above, the multi-parameter quantitative imaging method is applied to a nuclear magnetic resonance device including a T2 preparation sequence module and a variable flip angle multi-echo gradient echo sequence module connected to the T2 preparation sequence module, and includes: controlling an equivalent echo time by the T2 preparation sequence module and a flip angle by the variable flip angle multi-echo gradient echo sequence module, and scanning a target object to obtain a multi-parameter echo signal, wherein the multi-parameter echo signal includes a plurality of sets of multi-echo gradient signals corresponding to a plurality of flip angles at the same equivalent echo time and a plurality of sets of multi-echo gradient signals corresponding to the same flip angle at a plurality of equivalent echo times; and performing imaging processing on the multi-parameter echo signal based on image requirement configuration information to obtain a required multi-parameter quantitative image. The present application combines T2 preparation and variable flip angle techniques, and can obtain a multi-parameter echo signal by one scan, and obtain a multi-parameter quantitative image after imaging processing, thereby improving parameter imaging efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1A schematic diagram of a parameter quantitative image sequence acquisition provided by the related art;

[0017] Figure 2 A schematic diagram of a parameter quantitative image sequence acquisition provided by the related art;

[0018] Figure 3 A schematic diagram of a parameter quantitative image sequence acquisition provided by the related art;

[0019] Figure 4 A flowchart of a multi-parameter quantitative imaging method provided by an embodiment of the present application;

[0020] Figure 5 A schematic diagram of a multi-echo sequence provided by an embodiment of the present application;

[0021] Figure 6 A schematic diagram of a multi-parameter quantitative imaging apparatus provided by an embodiment of the present application;

[0022] Figure 7 A schematic diagram of a nuclear magnetic resonance device provided by an embodiment of the present application;

[0023] Figure 8 A block diagram of an electronic device provided by an embodiment of the present application. DETAILED DESCRIPTION

[0024] Embodiments of the present application are described in detail below with reference to the accompanying drawings, in which examples of embodiments are shown, and in which like or similar designations denote like or similar elements or elements having the same or similar functions throughout the figures. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to explain the present application, and cannot be understood as limiting the present application.

[0025] Magnetic Resonance Imaging (MRI) is one of important imaging methods in modern medical imaging, and is widely used in clinical medical imaging assisted diagnosis. In clinical applications, lesions are usually identified according to parameter images obtained from magnetic resonance signals and experiences of clinical diagnosis doctors, so as to diagnose and analyze diseases.

[0026] Quantitative MRI (qMRI) is different from conventional MRI imaging. qMRI is a kind of technology that uses MRI signals obtained by satisfying a certain acquisition method, and quantifies magnetic resonance parameters through certain post-processing and reconstruction. The quantitative images obtained by qMRI directly reflect the quantitative information of a certain magnetic resonance parameter of biological tissue, and can intuitively analyze and distinguish lesions by the size of the quantitative value, thereby providing a more accurate basis for clinical diagnosis and analysis of diseases.

[0027] In some examples, T1 parameter imaging method based on IR (Inversion Recovery) sequence is used, which needs to set different TI (Inversion time) time, collect MR signals at different time points on T1 relaxation curve, and then obtain T1 value of the tissue through exponential signal curve fitting. This method has the advantage of accurate T1 measurement, and is therefore considered as the gold standard method for T1 measurement. The disadvantage is that the scan time of the sequence is very long, which leads to the fact that it cannot be used in clinical MRI imaging. T1 mapping technology based on VFA (Variable Flip Angle) method needs to set multiple different flip angles in the sequence, and then calculate T1 value through multi-point fitting of MR signals. In recent years, with the development of qMRI technology, only two flip angles can be used to obtain accurate T1 measurement results in the VFA method, which makes T1 mapping based on the VFA method widely used in clinical qMRI.

[0028] In some examples, T2 parameter imaging method based on SE (Spin Echo) sequence with different echo times is used, which needs to use the same SE sequence to collect MR signals at different echo times, and then obtain T2 measurement results through T2 exponential decay curve fitting of the signals. The advantage of this method for measuring T2 based on SE sequence with different echo times is that it is not affected by the sequence refocusing pulse and can obtain accurate T2 measurement results. The disadvantage is that each sequence can only collect MR signals at one TE (Time of Echo) time, which makes the total scan time of the sequence longer, and thus limits its application in clinical qMRI. T2 parameter imaging technology based on T2 preparation sequence is also used, which uses a preset combination of pulses to form MR signals with a certain equivalent TE and a certain T2 weight, and then uses a fast gradient echo sequence to collect MR signals. By setting T2 preparation pulses with different equivalent TE to collect multiple MR signals with different equivalent TE (with different T2 weight), and finally obtaining T2 measurement results through multi-point T2 exponential decay curve fitting. The advantage of this T2 parameter imaging method based on T2 preparation is fast scan time, which is widely used in clinical fast qMRI imaging.

[0029] In qMRI, T2 * or R2 * The method of mapping almost all uses the method based on multi-echo GRE sequence, which collects MR signals of GRE sequence at different echo times, and obtains T2 * exponential decay curve fitting, T2 * or R2 *Measurement results.

[0030] However, the above qMRI methods are all based on a single sequence scan to obtain a parameter quantitative map, and cannot simultaneously obtain quantitative maps of multiple different parameters. In addition, the overall scan time of the conventional qMRI methods is relatively long when simultaneously obtaining these quantitative images, which can lead to poor patient tolerance and easy misalignment between different parameter images.

[0031] In some examples, more than one parameter quantitative image is obtained by a single sequence scan, including the DESPOT1 / T2 method, the principle of the VFA method, using a spoiled gradient echo sequence (SPGR) and a steady state free precession gradient echo sequence (SSFP), respectively acquiring SPGR signals of different flip angles and SSFP signals of different flip angles, using the SPGR signals to generate a T1 map, and then generating a T2 map according to the generated T1 map and the SSFP signals. However, this method only needs to use a short TR (Repetition Time) sequence design, so its advantage is that the scanning speed is very fast, but the disadvantage is that the T2 measurement result is limited by the accuracy of the T1 map calculation, so it is rarely used in clinical qMRI. From the principle of the DESPOT1 / T2 method, it can be seen that the generation of the T2 map needs the help of the T1 quantitative result of DESPOT1, and in MRI imaging, the solving process from MR signal to MR parameter will be affected by various disturbances, thereby causing a certain deviation between the measurement result and the actual parameter value. Therefore, the calculation result of DESPOT2 not only introduces errors due to the measurement of SSFP signals itself, but also introduces errors due to the calculation of DESPOT1, and this error will be further amplified along with the calculation of DESPOT1. That is, the T1 map measured by DESPOT1 itself has a certain error, and the T2 map measured by DESPOT2 has errors not only from the SSFP signals itself but also from DESPOT1, which leads to low measurement accuracy of the DESPOT1 / T2 method.

[0032] In some examples, more than one parameter quantitative image is obtained by a single sequence scan, and also includes a method for simultaneously obtaining T1 and T2 maps based on T2 preparation. This method combines the T2 preparation method and the IR-T1 mapping sequence, and the combined sequence acquisition mode is as shown in Figure 1 . Figure 1 The entire T2 preparation module is indicated by part 11, the equivalent echo time of which is TEprep, 111 and 113 indicate the excitation pulses (usually 90° pulses) used, and 112 indicates a refocusing pulse (hereFigure 1 Two adiabatic inversion pulses are used to achieve the refocusing effect), and 121 and 122 represent the rapid gradient echo sequence acquisition modules. Specifically, in the first step, a T2 preparation module is applied to form a magnetization intensity with a certain T2 weight, and then the magnetization vector is reversed to prepare for subsequent signal acquisition at different TI moments; in the second step, a rapid gradient echo imaging sequence is applied at TI1 and TI2 moments after the T2 preparation module to acquire MR signals; in the third step, the TEprep time of the T2 preparation module in the first step is changed and the first and second steps are repeated; in the fourth step, based on the data acquired in the first, second, and third steps, the MR signals at the same TI moment and different TEprep times are used to generate a T2map, and the MR signals at the same TEprep time and different TI moments are used to generate a T1map. This method based on T2 preparation and IR sequence essentially integrates the measurement of different parameters into one sequence, and generates quantitative results of different parameters by processing different MR signals. This T1 and T2 quantitative method based on the combination of T2 preparation and IR technology makes up for the shortcomings of the low accuracy of DESPOT1 / T2, but like the DESPOT1 / T2 method, it lacks T2 * or R2 * Quantitative results.

[0033] In some examples, more than one parameter quantitative image is obtained, and a STAGE (Strategically Acquired Gradient Echo Imaging, STAGE) acquisition strategy is also included to simultaneously obtain multiple parameter quantitative images, multiple parameter weighted images, and multiple vascular images. Specifically, the schematic diagram of the sequence is as follows Figure 2 This technology uses a multi-echo gradient echo sequence, with the sequence flip angle of the first scan being θ1 and the repetition time being TR, and adopts a design method of full flow compensation of all directional gradients (corresponding to Figure 2 FC module in), respectively collect echo 11 to echo 1N There are N echo signals in total. The flip angle of the second scan sequence is θ2, the repetition time is also TR, and the other sequence structures are exactly the same as the first scan sequence. 21 to echo 2N There are N echo signals in total. According to the VFA principle, STAGE uses signals with the same echo time and different flip angles to generate T1map images. * or R2 * Mapping principle, STAGE uses the signals of different echoes at any flip angle to generate T2 * or R2 * In addition, STAGE can also use the generated T1map and T2* or R2 * map combined with single-TR gradient echo signal formula generates PD map, and uses multi-echo signal under any flip angle to generate QSM image. However, the STAGE technique is based on double flip angle, single-TR, multi-echo GRE sequence, and the advantage of this sequence is that the scanning speed is very fast, but due to the multi-echo GRE acquisition strategy, it cannot obtain T2 relaxation information, so that this acquisition strategy cannot obtain T2 parameter image.

[0034] In some examples, obtaining more than one parameter quantitative image also includes a multi-parametric MR imaging (MTP) acquisition strategy for simultaneously obtaining at least T1 map, T2 * map, PD map, QSM and the like. Specifically, the schematic diagram of the sequence is as shown in Figure 3 The acquisition strategy is based on variable flip angle technology, double-TR technology, flow velocity compensation technology and flow velocity encoding technology. The sequence flip angle of the first scan is α1, and the time of the two TRs is TR1 and TR2, respectively. N1 echo signals are acquired within TR1, and N2 echo signals are acquired within TR2. The flip angle of the second scan is α2, and the time of the two TRs is also TR1 and TR2. The number of echoes acquired is N1 and N2. Based on the VFA principle, the MTP technology uses the signal of any same echo under different flip angles to obtain T1 map. Based on the multi-echo T2 * imaging principle, the MTP uses the signal of different echoes under any flip angle to generate T2 * or R2 * map. In the PD map calculation, the T1 map and T2 * or R2 * map generated in the previous step are used in the expression of the magnetic resonance signal, and then the PD measurement result is generated. Finally, in the QSM reconstruction, the MTP technology uses different echo signals under any flip angle and within the same TR to generate QSM image according to the QSM reconstruction principle. However, the MTP technology uses a three-dimensional multi-echo GRE sequence and a double-TR acquisition strategy. The double-TR technology is different from the conventional single-TR multi-echo gradient echo sequence, and the sequence principle and the formula of the magnetic resonance signal intensity are also different. In actual scanning, the time of the two TRs is not consistent, and generally TR2 is greater than TR1 (generally TR2 = 5TR1), which will cause the scanning time to be prolonged, and the same as the STAGE technique, the acquired MR signal cannot extract T2 relaxation information, so that T2 parameter image cannot be generated.

[0035] Based on this, in order to obtain quantitative images of multiple parameters of magnetic resonance at the same time, the present application provides a method for multi-parameter quantitative imaging of magnetic resonance, which simultaneously obtains quantitative images of multiple parameters including T1, T2, T2 * or R2 * and the like through one scan.

[0036] Figure 4 The multi-parameter quantitative imaging method is an embodiment of the present application.

[0037] As an example, as shown in the figure, the multi-parameter quantitative imaging method includes: Figure 4

[0038] S401, controlling the equivalent echo time by the T2 preparation sequence module and controlling the flip angle by the variable flip angle multi-echo gradient echo sequence module, and scanning the target object to obtain multi-parameter echo signals, wherein the multi-parameter echo signals include multiple sets of multi-echo gradient signals corresponding to multiple flip angles at the same equivalent echo time and multiple sets of multi-echo gradient signals corresponding to the same flip angle at multiple equivalent echo times.

[0039] S402, performing imaging processing on the multi-parameter echo signals based on image requirement configuration information to obtain the required multi-parameter quantitative images.

[0040] Exemplarily, the above multi-parameter quantitative imaging method is applied to a nuclear magnetic resonance device, and the nuclear magnetic resonance device of the present application includes a T2 preparation sequence module and a variable flip angle multi-echo gradient echo sequence module connected to the T2 preparation sequence module. The echo sequence can be generated by controlling the length of the equivalent echo time by the T2 preparation module, and the echo sequence can be generated by controlling the size of the flip angle by the variable flip angle multi-echo gradient echo sequence module. The multi-echo sequence generated by the T2 preparation sequence module and the variable flip angle multi-echo gradient echo sequence module is used to scan the target object to obtain multi-parameter echo signals. Then, based on the image requirement configuration information, the multi-parameter echo signals are imaged to obtain the required multi-parameter quantitative images. It can be understood that the storage device connected to the nuclear magnetic resonance device or the storage module in the nuclear magnetic resonance device stores the multi-parameter echo signals. Then, based on the image requirement configuration information, the multi-parameter echo signals are imaged to obtain the required multi-parameter quantitative images. The image requirement configuration information can be selected by the user to represent which parameter quantitative image the user needs. The multi-parameter quantitative images include, for example, longitudinal relaxation T1 parameter images, transverse relaxation T2 parameter images, effective transverse relaxation T2 * parameter images, relaxation rate R2 * images and the like.

[0041] ​For example, multiple sets of multi-echo gradient signals corresponding to multiple flip angles at the same equivalent echo time and multiple sets of multi-echo gradient signals corresponding to the same flip angle at multiple equivalent echo times can be data-multiplexed. For example, the multi-echo gradient signals corresponding to the first flip angle at the first equivalent echo time can belong to both the multiple sets of multi-echo gradient signals corresponding to multiple flip angles at the same equivalent echo time and the multiple sets of multi-echo gradient signals corresponding to the same flip angle at multiple equivalent echo times. Data multiplexing can reduce the amount of data collected and improve efficiency. Alternatively, data non-multiplexing can be employed. For example, multiple sets of multi-echo gradient signals at the first and second flip angles are collected for the first equivalent echo time. When collecting multiple sets of multi-echo gradient signals corresponding to the same flip angle at multiple equivalent echo times, the first and second flip angles are no longer collected, and instead multiple sets of multi-echo gradient signals corresponding to the third flip angle at multiple equivalent echo times are collected. The echo times of different sets of multi-echo gradient signals within the multiple sets of multi-echo gradient signals can be the same.

[0042] The multi-parameter quantitative imaging method of the present application can obtain multi-parameter echo signals through one scan, and then perform imaging processing on the multi-parameter echo signals according to the image requirement configuration information, that is, the present application can obtain at least T1, T2, T2 through one scan. * or R2 * Compared with the traditional method of obtaining T1 parameter quantitative images once and then obtaining T2 parameter quantitative images and scanning again, the quantitative images of multiple parameters including T1 parameter quantitative images can save the number of scans and improve the imaging efficiency.

[0043] As an example, Figure 5 As shown, the T2 preparation sequence module includes a first tilt pulse, a first refocusing pulse, a second refocusing pulse and a second tilt pulse connected in sequence, the first tilt pulse and the second tilt pulse are used to tilt the magnetization vector downward and upward, and the first refocusing pulse and the second refocusing pulse are used to refocus the phase of the spinning protons in the transverse plane, wherein the equivalent echo time is the time interval between the first tilt pulse and the second tilt pulse.

[0044] For example, Figure 5 As shown, the multi-echo gradient echo sequence of the present application can be a spoiled gradient echo sequence (SPGR sequence). Of course, the multi-echo sequence can also be other types of sequences, such as a dual TR gradient echo sequence. Figure 5 The spoiled gradient echo sequence SPGR sequence is used as an example to illustrate. Figure 5 As shown in the sequence timing diagram, the sequence mainly consists of two parts: T2 preparation module and multi-echo SPGR sequence.

[0045] Exemplarily, the T2 preparation sequence module comprises a first tilt pulse, a first refocusing pulse, a second refocusing pulse and a second tilt pulse connected in sequence, the first tilt pulse can be a downward tilt pulse, and the second tilt pulse can be an upward tilt pulse, that is, the T2 preparation module is composed of two tilt pulses on the left and right sides, which respectively realize the functions of downward and upward tilting of the magnetization vector, and the two refocusing pulses (the first refocusing pulse and the second refocusing pulse) in the middle realize the phase refocusing function of the spin protons in the transverse plane. The time interval of the first tilt pulse and the second tilt pulse represents the equivalent echo time of the T2 preparation module, which can be represented by TEeq. The multi-echo SPGR sequence module is used to acquire multi-echo nuclear magnetic resonance signals corresponding to the equivalent echo time TEeq, and θ represents the flip angle of the SPGR sequence, and different flip angles are used in the SPGR sequence when the T2 preparation module with different equivalent echo times TEeq is combined. Echo1 to Echo N represent the acquired multi-echo signals. It should be noted that TEeq represents the equivalent echo time of the T2 preparation module, and TR represents the repetition time of the multi-echo sequence.

[0046] The simultaneous multi-parameter quantitative imaging method of the present application is based on the T2 preparation technology, the variable flip angle VFA technology and the multi-echo GRE sequence. The fast GRE sequence is used to acquire magnetic resonance signals with different equivalent echo times TEeq, different flip angles and different echo times. Through the reconstruction processing of different signals, at least a plurality of different parameter quantitative images including T1 map, T2 map, T2 * or R2 * map are generated simultaneously.

[0047] As an example, the multi-parameter echo signal comprises a plurality of groups of multi-echo gradient signals corresponding to a plurality of flip angles at the same equivalent echo time and a plurality of groups of multi-echo gradient signals corresponding to the same flip angle at a plurality of equivalent echo times. Data multiplexing is used, a total of five groups of multi-echo gradient signals are acquired, and then used in subsequent imaging processing. For example, a first group of echo signals corresponding to a first flip angle at a first equivalent echo time, a second group of echo signals corresponding to a second flip angle at the first equivalent echo time, a third group of echo signals corresponding to the second flip angle at a second equivalent echo time, a fourth group of echo signals corresponding to the second flip angle at a third equivalent echo time, and a fifth group of echo signals corresponding to the second flip angle at a fourth equivalent echo time are obtained; wherein the number of echoes in each group of echo signals is greater than or equal to 2.

[0048] Exemplarily, the target object is an object to be detected. The equivalent echo time can be configured in advance for the T2 preparation module, and the flip angle can also be configured in advance for the variable flip angle multi-echo gradient echo sequence module. The multiple sets of echo signals can be stored in a storage module in the nuclear magnetic resonance device or a storage device connected to the nuclear magnetic resonance device, and subsequently processed according to image requirement configuration information to obtain a required multi-parameter quantitative image. The multi-parameter quantitative image is, for example, a longitudinal relaxation T1 parameter image, a transverse relaxation T2 parameter image, an effective transverse relaxation T2 * parameter image, a relaxation rate R2 * parameter image, and the like.

[0049] Exemplarily, the first equivalent echo time can be TEeq1, the second equivalent echo time can be TEeq2, the third equivalent echo time can be TEeq3, and the fourth equivalent echo time can be TEeq4. The first flip angle can be θ1, and the second flip angle can be θ2. Specifically, a first set of multi-echo gradient echo signals at the first equivalent echo time TEeq1 and the first flip angle θ1 is acquired; a second set of multi-echo gradient echo signals at the first equivalent echo time TEeq1 and the second flip angle θ2 is acquired; a third set of multi-echo gradient echo signals at the second equivalent echo time TEeq2 and the second flip angle θ2 is acquired; a fourth set of multi-echo gradient echo signals at the third equivalent echo time TEeq3 and the second flip angle θ2 is acquired; and a fifth set of multi-echo gradient echo signals at the fourth equivalent echo time TEeq4 and the second flip angle θ2 is acquired. It should be noted that the number of echoes of each set of echo signals is greater than or equal to 2. The number of echoes of each set of echo signals is exemplarily 2 in this application, and of course, the number of echoes of each set of echo signals can also be other numbers. After the signals are acquired, various types of parameter quantitative images can be reconstructed according to user requirements. For example, a T1 map is generated using the same echo signals at the first equivalent echo time TEeq1 and the first and second flip angles. A T2 * or R2 * map is generated using all echo signals at any equivalent echo time TEeq and any flip angle. A T2 map is generated using the same echo signals at all equivalent echo times TEeq 1-4 under the second flip angle.

[0050] The application can obtain multiple sets of echo signals through one scan, and subsequently perform imaging processing on the echo signals according to image requirement configuration information to obtain quantitative images of multiple parameters including at least T1, T2, T2 * or R2 * , and the like.

[0051] As an example, the variable flip angle multi-echo gradient echo sequence module includes at least one of an SPGR sequence multi-echo gradient echo sequence module and a dual-TR gradient echo sequence module.

[0052] Exemplarily, the variable flip angle multi-echo gradient echo sequence module after the T2 preparation module can be a SPGR sequence multi-echo gradient echo sequence module, that is, a SPGR sequence is used, but is not limited to the SPGR sequence, and can also be combined with a dual-TR gradient echo sequence module, that is, a dual-TR gradient echo sequence is used, for generating T1, T2, B1map and the like parameter images, wherein the B1map is a radio frequency field map distribution. The following application is described by taking the SPGR sequence multi-echo gradient echo sequence module as an example. It should be noted that the SPGR sequence can be a two-dimensional SPGR imaging sequence or a three-dimensional SPGR imaging sequence.

[0053] As an example, the number of echo signals per group is 2. Dual-echo gradient echo signals with a first equivalent echo time TEeq1 and a first flip angle θ1 are collected, and the echo signals are denoted as S 111 , S 112 , respectively, and the echo times are TE1 and TE2, respectively. Dual-echo gradient echo signals with a first equivalent echo time TEeq1 and a second flip angle θ2 are collected, and the echo signals are denoted as S 121 , S 122 , respectively, and the echo times are TE1 and TE2, respectively. Dual-echo gradient echo signals with a second equivalent echo time TEeq2 and a second flip angle θ2 are collected, and the echo signals are denoted as S 221 , S 222 , respectively, and the echo times are TE1 and TE2, respectively. Dual-echo gradient echo signals with a third equivalent echo time TEeq3 and a second flip angle θ2 are collected, and the echo signals are denoted as S 321 , S 322 , respectively, and the echo times are TE1 and TE2, respectively. Dual-echo gradient echo signals with a fourth equivalent echo time TEeq4 and a second flip angle θ2 are collected, and the echo signals are denoted as S 421 , S 422 , respectively, and the echo times are TE1 and TE2, respectively.

[0054] It should be noted that the echo time TE is not the same as the repetition time TR of the echo sequence. The echo time can be regarded as the time of one echo, and the TR is the repetition time of the entire echo sequence.

[0055] As an example, based on the image requirement configuration information, the multi-parameter echo signals are processed to obtain the required multi-parameter quantitative images, including:

[0056] In the case where the image requirement configuration information indicates that the required multi-parameter quantitative images include a longitudinal relaxation T1 parameter image, the echo signals of the same echo time corresponding to a plurality of flip angles at the same equivalent echo time are processed to obtain the longitudinal relaxation T1 parameter image.

[0057] Exemplarily, when the image requirement configuration information indicates that the required multi-parameter quantitative image comprises a longitudinal relaxation T1 parameter image, according to the principle of the variable flip angle method, imaging processing of echo signals of the same echo time corresponding to multiple flip angles under the same equivalent echo time can obtain the longitudinal relaxation T1 parameter image. For example, MR signals at different time points on a T1 relaxation curve are collected, and the T1 value is calculated by multi-point fitting of the MR signals.

[0058] As an example, when the image requirement configuration information indicates that the required multi-parameter quantitative image comprises a longitudinal relaxation T1 parameter image, imaging processing can be performed in combination with a certain echo signal in the first group of echo signals and a certain echo signal in the second group of echo signals, and it is required to ensure that the echo times of the echo signals used in the first group of echo signals and the echo signals used in the second group of echo signals are the same. For example, the first target echo signal in the first group of echo signals can be S 111 , and the second target echo signal in the second group of echo signals can be S 121 . Of course, the first target echo signal can also be S 112 , and the second target echo signal can also be S 122 , and it is required to ensure that the echo times of the first target echo signal and the second target echo signal are the same, that is, through the combination of S 111 and S 121 , or the combination of S 112 and S 122 , the longitudinal relaxation T1 parameter image can be obtained. Of course, if the number of echo signals of each group of echo signals is n, the echo signals of other echo times, for example, S 11n and S 12n , can also be used.

[0059] As an example, based on the image requirement configuration information, the multi-parameter echo signals are imaged to obtain the required multi-parameter quantitative image, comprising: when the image requirement configuration information indicates that the required multi-parameter quantitative image comprises a transverse relaxation T2 parameter image, imaging processing of echo signals of the same echo time corresponding to the same flip angle under multiple equivalent echo times is performed to obtain the transverse relaxation T2 parameter image.

[0060] Exemplarily, when the image requirement configuration information indicates that the required multi-parameter quantitative image comprises a transverse relaxation T2 parameter image, imaging processing of echo signals of the same echo time corresponding to the same flip angle under multiple equivalent echo times is performed to obtain the transverse relaxation T2 parameter image.

[0061] Exemplarily, after the T2 preparation module is applied, the longitudinal magnetization vector strength can be expressed as follows:

[0062]

[0063] wherein M TEeq represents the longitudinal magnetization vector strength, M0 represents the initial longitudinal magnetization strength, TEeq represents the equivalent echo time of the T2 preparation module, and T2 represents the transverse relaxation time.

[0064] The expression of the SPGR multi-echo sequence signal is as follows:

[0065]

[0066] wherein S SPGR represents the signal strength of the spoiled gradient echo sequence, θ represents the flip angle of the pulse sequence, M0 represents the initial longitudinal magnetization strength, TR represents the repetition time of the pulse sequence, T1 represents the longitudinal relaxation time of the tissue, and T2 * represents the transverse relaxation time.

[0067] The expression of the spoiled gradient echo sequence after the T2 preparation module is applied can be expressed as follows:

[0068]

[0069] wherein S(θ) represents the signal strength of the SPGR sequence after the T2 preparation module is applied.

[0070] By substituting the expression of the SPGR multi-echo sequence signal into the spoiled gradient echo sequence expression above, another form of the spoiled gradient echo sequence expression after the T2 preparation module is applied is obtained, as shown below:

[0071]

[0072] According to the spoiled gradient echo sequence expression after the T2 preparation module is applied above, the echo signals corresponding to the same echo time at different equivalent echo times and the same flip angle are subjected to single-exponential fitting or multi-exponential fitting processing, and the transverse relaxation T2 parameter is calculated to obtain the transverse relaxation T2 parameter image.

[0073] As an example, when the image requirement configuration information indicates that the required multi-parameter quantitative image includes the transverse relaxation T2 parameter image, the second target echo signal in the second group of echo signals, the third target echo signal in the third group of echo signals, the fourth target echo signal in the fourth group of echo signals, and the fifth target echo signal in the fifth group of echo signals can be taken, and the transverse relaxation T2 parameter is obtained by performing exponential fitting processing according to the spoiled gradient echo sequence expression after the T2 preparation module is applied above. It should be noted that the echo times of the second target echo signal, the third target echo signal, the fourth target echo signal, and the fifth target echo signal are the same, for example, S 121As the second target echo signal, S 221 As the third target echo signal, S 321 The fourth target echo signal, S 421 As the fifth target echo signal, according to data S 121 , S 221 , S 321 , S 421 Exponential fitting is performed to obtain the transverse relaxation T2 parameter, and a transverse relaxation T2 parameter image is obtained after imaging. Of course, data or S 122 , S 222 , S 322 , S 422 Exponential fitting is performed, and only the same echo time needs to be ensured.

[0074] As an example, based on the image requirement configuration information, the multi-parameter echo signal is imaged and processed to obtain the required multi-parameter quantitative image, including:

[0075] In the case where the image requirement configuration information indicates that the required multi-parameter quantitative image includes the effective transverse relaxation T2 * and / or the relaxation rate R2 * parameter image, at least two target echo signals corresponding to any flip angle at any equivalent echo time are imaged and processed to obtain the effective transverse relaxation T2 * and / or the relaxation rate R2 * parameter image, wherein the echo times of the at least two target echo signals are different.

[0076] Exemplarily, the effective transverse relaxation T2 * parameter and the relaxation rate R2 * parameter are inversely related, that is The effective transverse relaxation T2 * parameter is equivalent to obtaining the relaxation rate R2 * parameter. When the image requirement configuration information indicates that the required multi-parameter quantitative image includes the effective transverse relaxation T2 * and / or the relaxation rate R2 * parameter image, at least two target echo signals corresponding to any flip angle at any equivalent echo time are imaged and processed to obtain the effective transverse relaxation T2 * and / or the relaxation rate R2 * parameter image, wherein the echo times of the at least two target echo signals are different.

[0077] As an example, the image requirement configuration information indicates that the required multi-parameter quantitative image includes the effective transverse relaxation T2 * and / or the relaxation rate R2 *The parameter images can be generated from the first set of echo signals S 111 , the second set of echo signals S 112 , the third set of echo signals S 121 , the fourth set of echo signals S 122 , the fifth set of echo signals S 221 , or the sixth set of echo signals S 222 , or the seventh set of echo signals S 321 , or the eighth set of echo signals S 322 , or the ninth set of echo signals S 421 , or the tenth set of echo signals S 422 , by single-exponential or multi-exponential fitting of T2 * or R2 * , to obtain T2 * or R2 * measurements, to generate effective transverse relaxation T2 * and / or relaxation rate R2 * parameter images. It is noted that the number of echoes in a set of echo signals can be 2 as described above, and more echoes can also be used.

[0078] The simultaneous multi-parameter quantitative imaging method based on T2 preparation and VFA technique proposed in the present application uses T2 preparation modules with different equivalent TEeq in combination with multi-echo SPGR sequences with variable flip angles to acquire MR signals with different T2 weights, different flip angles, and different echo times, and through reconstruction and processing of the acquired signals, simultaneously generates a plurality of parameter quantitative images including T1 map, T2 map, T2 * or R2 * map, and the like.

[0079] As an example, the multi-parameter quantitative images include at least one of longitudinal relaxation T1 parameter image, transverse relaxation T2 parameter image, effective transverse relaxation T2 * parameter image, relaxation rate R2 * parameter image, radio frequency magnetic field B1 parameter image, magnetic susceptibility QSM parameter image, proton density PD parameter image, and weighted image.

[0080] Exemplarily, the parameter quantitative images of the present application are not limited to the longitudinal relaxation T1, transverse relaxation T2, effective transverse relaxation T2 * , relaxation rate R2 * quantitative images mentioned above, but can also realize quantitative imaging of other parameters, such as radio frequency magnetic field B1 parameter image, magnetic susceptibility QSM parameter image, proton density PD parameter image, and other conventional weighted contrast imaging such as T1w, T2 * w, SWI, and the like.

[0081] The present application also proposes a multi-parameter quantitative imaging device.

[0082] As an example, as shown in Figure 6 The multi-parameter quantitative imaging apparatus 600 is applied to a nuclear magnetic resonance device including a T2 preparation sequence module and a variable flip angle multi-echo gradient echo sequence module connected with the T2 preparation sequence module, and the multi-parameter quantitative imaging apparatus 600 includes: a scanning module 601 configured to control an equivalent echo time by an equivalent echo time T2 preparation sequence module and control a flip angle by an equivalent echo time variable flip angle multi-echo gradient echo sequence module, and perform scanning on a target object to obtain a multi-parameter echo signal, wherein the equivalent echo time multi-parameter echo signal includes a plurality of groups of multi-echo gradient signals corresponding to a plurality of flip angles at a same equivalent echo time and a plurality of groups of multi-echo gradient signals corresponding to a same flip angle at a plurality of equivalent echo times; and a processing module 602 configured to perform imaging processing on the multi-parameter echo signal based on image requirement configuration information to obtain a required multi-parameter quantitative image.

[0083] The present application also provides a nuclear magnetic resonance device,

[0084] As an example, as shown in Figure 7 The nuclear magnetic resonance device 700 includes a T2 preparation sequence module 701 and a variable flip angle multi-echo gradient echo sequence module 702 connected with the T2 preparation sequence module, and the nuclear magnetic resonance device 700 is configured to implement the steps of the multi-parameter quantitative imaging method.

[0085] The present application also provides a computer readable storage medium.

[0086] In this embodiment, the computer readable storage medium stores a computer program, and the computer program is executed by a processor to implement the steps of the multi-parameter quantitative imaging method.

[0087] Figure 8 The block diagram of the electronic device provided in the present application embodiment.

[0088] The present application embodiment provides an electronic device including a memory and a processor, the memory stores a computer program, and the processor executes the computer program to implement the multi-parameter quantitative imaging method.

[0089] As shown in Figure 8 To facilitate understanding, the present application embodiment shows a specific electronic device.

[0090] Electronic device is intended to represent a variety of forms including but not limited to laptops, desktops, workstations, personal digital assistants, servers, blades, mainframes, and other appropriate computers. Electronic device can also represent a variety of forms of mobile devices such as personal digital assistants, cellular phones, smart phones, wearable devices, and other similar computing devices. The components shown herein, their connections, and relationships, and their functions, are meant to be examples only, and are not intended to limit implementations of the present disclosure described and / or claimed in this document.

[0091] As shown in Figure 8 The electronic device includes a computing unit 801 that can perform various appropriate actions and processes in accordance with a computer program stored in a read-only memory (ROM) 802 or a computer program loaded from a storage unit 808 into a random access memory (RAM) 803. Various programs and data required for operation of the electronic device can also be stored in the RAM 803. The computing unit 801, the ROM 802, and the RAM 803 are connected to each other through a bus 804. An input / output (I / O) interface 805 is also connected to the bus 804.

[0092] A plurality of components in the electronic device are connected to the I / O interface 805, including an input unit 806 such as a keyboard, a mouse, and the like; an output unit 807 such as various types of displays, a speaker, and the like; the storage unit 808 such as a magnetic disk, an optical disk, and the like; and a communication unit 809 such as a network card, a modem, a wireless communication transceiver, and the like. The communication unit 809 allows the electronic device to exchange information / data with other devices through a computer network such as the Internet and / or various telecommunication networks.

[0093] The computing unit 801 can be various general and / or special purpose processing components with processing and computing capabilities. Some examples of the computing unit 801 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various specialized artificial intelligence (AI) computing chips, various computing units running machine learning model algorithms, a digital signal processor (DSP), and any appropriate processor, controller, microcontroller, and the like. The computing unit 801 performs various methods described above, such as the multi-parametric quantitative imaging method. For example, in some embodiments, the multi-parametric quantitative imaging method can be implemented as a computer software program tangibly embodied in a machine-readable medium, such as the storage unit 808. In some embodiments, part or all of the computer program can be loaded and / or installed onto the electronic device via the ROM 802 and / or the communication unit 809. When the computer program is loaded into the RAM 803 and executed by the computing unit 801, the multi-parametric quantitative imaging method described above can be performed. Alternatively, in other embodiments, the computing unit 801 can be configured, by way of firmware or otherwise, to perform the multi-parametric quantitative imaging method.

[0094] It should be noted that the logical and / or steps represented in the flowcharts or otherwise described herein, for example, can be considered as a list of executable instructions for implementing logical functions and can be embodied in any computer-readable medium for use by or in connection with an instruction execution system, apparatus, or device, such as a computer-based system, processor- containing system, or other system that can fetch the instructions from the instruction execution system, apparatus, or device and execute the instructions, or a combination thereof. For purposes of this application, a "computer-readable medium" can be any apparatus that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of the computer-readable medium include the following: an electrical connection having one or more wires (electrical apparatus), a portable computer diskette (magnetic apparatus), a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber (optical apparatus), and a portable compact disc read-only memory (CDROM). Additionally, the computer-readable medium can even be paper or another suitable medium upon which the program is printed, as the program can be electronically captured, for example, via an optical scanner, then compiled, interpreted, or otherwise processed, and stored in a computer memory in order to be executed.

[0095] It should be understood that portions of the application can be implemented in hardware, software, firmware, or combinations thereof. In the above embodiments, multiple steps or methods can be implemented in software or firmware that is stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, implementation can be with any or a combination of the following technologies, which are all well-known in the art: a discrete logic circuit having logic gates for implementing logic functions upon an application of data signals, an application specific integrated circuit having appropriate combinational logic gates, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0096] In the description of the present application, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are contained in at least one embodiment or example of the present application. In the present application, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0097] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0098] In addition, the terms "first", "second", etc. used in the embodiments of the present application are only for the purpose of description, and can not be understood as indicating or implying relative importance, or implicitly indicating the number of technical features referred to in the embodiments. Therefore, the features defined with "first", "second" and the like in the embodiments of the present application can be explicitly or implicitly indicated to include at least one of the features. In the description of the present application, the meaning of the word "plurality" is at least two or two or more, such as two, three, four, etc., unless otherwise specifically limited in the embodiments.

[0099] In the present application, unless otherwise explicitly specified or limited in the embodiments, the terms "mounting", "connecting", "connecting" and "fixing" and the like appearing in the embodiments should be understood in a broad sense, for example, the connection can be fixed connection, or detachable connection, or integral, can be understood, or mechanical connection, electrical connection, etc. Of course, it can also be directly connected, or indirectly connected through an intermediate medium, or it can be the internal communication of two elements, or the interaction relationship of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific implementation situation.

[0100] In the present application, unless otherwise explicitly specified and limited, the first feature is "on" or "under" the second feature. The first and second features can be in direct contact, or the first and second features can be indirectly contacted through an intermediate medium. Moreover, the first feature can be above, above and above the second feature, or only indicate that the first feature is higher than the second feature in horizontal height. The first feature can be below, below and below the second feature, or only indicate that the first feature is lower than the second feature in horizontal height.

[0101] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limiting the present application, and those skilled in the art can make changes, modifications, replacements and modifications to the above embodiments within the scope of the present application.

Claims

1. A multi-parameter quantitative imaging method, characterized in that: The method is applied to a nuclear magnetic resonance device, the nuclear magnetic resonance device including a T2 preparation sequence module and a variable flip angle multi-echo gradient echo sequence module connected to the T2 preparation sequence module, and the method includes: The equivalent echo time is controlled by the T2 preparation sequence module, and the flip angle is controlled by the variable flip angle multi-echo gradient echo sequence module to scan the target object and obtain a multi-parameter echo signal, wherein the multi-parameter echo signal includes multiple groups of multi-echo gradient signals corresponding to multiple flip angles at the same equivalent echo time and multiple groups of multi-echo gradient signals corresponding to the same flip angle at multiple equivalent echo times; The multi-parameter echo signal is subjected to imaging processing based on the image requirement configuration information to obtain the required multi-parameter quantitative image.

2. The multi-parameter quantitative imaging method according to claim 1, characterized in that: The T2 preparation sequence module includes a first tilt pulse, a first refocusing pulse, a second refocusing pulse and a second tilt pulse connected in sequence, wherein the first tilt pulse and the second tilt pulse are used to perform downward tilting and upward tilting processing on the magnetization vector, and the first refocusing pulse and the second refocusing pulse are used to perform refocusing processing on the phase of the spinning protons in the transverse plane, wherein the equivalent echo time is the time interval between the first tilt pulse and the second tilt pulse.

3. The multi-parameter quantitative imaging method according to claim 1, characterized in that: The imaging processing of the multi-parameter echo signal based on the image requirement configuration information to obtain the required multi-parameter quantitative image includes: When the image requirement configuration information indicates that the required multi-parameter quantitative image includes a longitudinal relaxation T1 parametric image, the echo signals of the same echo time corresponding to multiple flip angles at the same equivalent echo time are imaged and processed to obtain the longitudinal relaxation T1 parametric image.

4. The multi-parameter quantitative imaging method according to claim 1, characterized in that: The imaging processing of the multi-parameter echo signal based on the image requirement configuration information to obtain the required multi-parameter quantitative image includes: When the image requirement configuration information indicates that the required multi-parameter quantitative image includes a transverse relaxation T2 parametric image, imaging processing is performed on echo signals of the same echo time corresponding to the same flip angle under multiple equivalent echo times to obtain a transverse relaxation T2 parametric image.

5. The multi-parameter quantitative imaging method according to claim 1, characterized in that: The imaging processing of the multi-parameter echo signal based on the image requirement configuration information to obtain the required multi-parameter quantitative image includes: The image requirement configuration information indicates the required multi-parameter quantitative image including effective transverse relaxation T2 * and / or relaxation rate R2 * In the case of parametric imaging, imaging processing is performed on at least two target echo signals corresponding to any flip angle at any equivalent echo time to obtain the effective transverse relaxation T2 * and / or relaxation rate R2 * A parametric image, wherein the echo times of the at least two target echo signals are different.

6. The multi-parameter quantitative imaging method according to claim 1, characterized in that: The multi-parameter quantitative image includes longitudinal relaxation T1 parameter image, transverse relaxation T2 parameter image, effective transverse relaxation T2 * Parameter image, relaxation rate R2 * At least one of a parameter image, a radio frequency magnetic field B1 parameter image, a magnetic susceptibility QSM parameter image, a proton density PD parameter image, and a weighted image.

7. The multi-parameter quantitative imaging method according to claim 1, characterized in that: The variable flip angle multi-echo gradient echo sequence module includes at least one of an SPGR sequence multi-echo gradient echo sequence module and a dual TR gradient echo sequence module.

8. A multi-parameter quantitative imaging device, characterized in that: The device is applied to a nuclear magnetic resonance device, which includes a T2 preparation sequence module and a variable flip angle multi-echo gradient echo sequence module connected to the T2 preparation sequence module. The device includes: a scanning module, configured to control the equivalent echo time by the T2 preparation sequence module and the flip angle by the variable flip angle multi-echo gradient echo sequence module, to scan the target object and obtain a multi-parameter echo signal, wherein the multi-parameter echo signal includes multiple groups of multi-echo gradient signals corresponding to multiple flip angles at the same equivalent echo time and multiple groups of multi-echo gradient signals corresponding to the same flip angle at multiple equivalent echo times; The processing module is used to perform imaging processing on the multi-parameter echo signal based on the image requirement configuration information to obtain the required multi-parameter quantitative image.

9. A nuclear magnetic resonance device, characterized in that The nuclear magnetic resonance device includes a T2 preparation sequence module and a variable flip angle multi-echo gradient echo sequence module connected to the T2 preparation sequence module. The nuclear magnetic resonance device is used to implement the steps of the method described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that A computer program is stored thereon, and when the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

Images