Sodium ion magnetic resonance imaging method, apparatus, and medical imaging system

Abstract

The embodiment of the application discloses a sodium ion magnetic resonance imaging method, device and medical imaging system. The method comprises the following steps: performing magnetic resonance imaging on an imaging target by using a hydrogen proton quantitative measurement sequence; for any two adjacent layer excitations within a TR, one or more rounds of sodium ion excitation and echo acquisition processes of sodium ion magnetic resonance imaging are inserted from the completion of the previous layer excitation and echo acquisition to the start of the next layer excitation. The embodiment of the application realizes the interleaving of sodium ion imaging and hydrogen proton imaging within one TR, and improves the imaging efficiency.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of medical imaging, in particular to a sodium ion magnetic resonance imaging method, device and medical imaging system. BACKGROUND

[0002] Sodium ions play an important role in the osmotic regulation of human and cell physiology, and the extracellular concentration is about 10 times higher than the intracellular concentration. The sodium ion concentration in tissues is very sensitive to pathological changes, and sodium ion MRI (Magnetic Resonance Imaging) can quantitatively measure the sodium ion concentration in tissues in a non-invasive manner. Changes in sodium ion concentration can provide more information about changes and damage such as cell accumulation, dehydration, tumor edema, neovascularization, brain metabolite clearance, etc.

[0003] The average concentration of sodium ions in the human body is low (45 mmol / L), and the MRI sensitivity is poor (9.2%), and the MR signal intensity produced is about 4 orders of magnitude lower than that of hydrogen. Sodium ion MRI requires a longer acquisition time to achieve high signal-to-noise ratio imaging. In addition, the relaxation time of the MR signal of sodium ions is much shorter than that of the MR signal of hydrogen protons, of which 60% of the signal decay relaxation time is 2-5 ms, and an ultra-short echo sequence is usually used for acquisition.

[0004] Due to the low resolution of sodium ion imaging, when performing MR examination on the imaging target, not only sodium ion imaging but also hydrogen proton imaging is usually required to obtain hydrogen proton contrast such as T2 (transverse relaxation time) weighting, T1 (longitudinal relaxation time) weighting, dark fluid T2 weighting and PD (Proton Density) weighting, etc. Hydrogen proton contrast is used to observe the local details of the imaging target. The current imaging methods mainly include the following:

[0005] I. Sequential acquisition of sodium ion imaging and hydrogen proton imaging

[0006] Sodium ion imaging and hydrogen proton imaging are sequentially performed in different acquisitions. This sequential acquisition method results in prolonged MR examination time and low efficiency.

[0007] II. Interleaved acquisition of sodium ion imaging and hydrogen proton contrast

[0008] Sodium ion imaging is interleaved with hydrogen proton contrast acquisition to solve the low efficiency problem of sequential acquisition. For example, sodium ion imaging is first performed, and then a specific hydrogen proton contrast is acquired before the next TR starts. Since different acquisition parameters are required for different hydrogen proton contrasts, each hydrogen proton contrast needs to be acquired separately, i.e., through different hydrogen proton scanning processes. Therefore, although this method improves efficiency compared to sequential acquisition, since each hydrogen proton contrast needs to be acquired separately, when the imaging target moves within a certain time, the consistency of the hydrogen proton contrast acquired during motion with the sodium ion image is poor, which is not conducive to the fusion of the hydrogen proton contrast and the sodium ion image.

[0009] III. Using a dedicated sodium ion imaging protocol

[0010] Some existing technologies focus on optimizing sodium ion imaging protocols independently, such as using ultra-high field MRI systems (e.g., 7T MRI) to improve the SNR (Signal-to-Noise Ratio) of sodium ions and shorten the acquisition time. However, these methods do not solve the efficiency problem of simultaneously implementing sodium ion imaging and hydrogen proton imaging in one MR examination. SUMMARY

[0011] Therefore, the embodiments of the present application, on the one hand, propose a sodium ion MRI method and device to improve imaging efficiency when sodium ion imaging and hydrogen proton imaging need to be simultaneously implemented in one MR examination; on the other hand, propose a medical imaging system to improve imaging efficiency when sodium ion imaging and hydrogen proton imaging need to be simultaneously implemented in one MR examination.

[0012] A sodium ion magnetic resonance imaging method, the method comprising:

[0013] Performing magnetic resonance imaging on the imaging target using a hydrogen proton quantitative measurement sequence;

[0014] For any two adjacent layer excitations within a repetition time TR, one or more sodium ion excitation and echo acquisition processes of sodium ion magnetic resonance imaging are inserted from the completion of the previous layer excitation and echo acquisition to the start of the next layer excitation.

[0015] Before the performing magnetic resonance imaging on the imaging target using a hydrogen proton quantitative measurement sequence, further comprising:

[0016] Performing one or more sodium ion excitation and echo acquisition processes.

[0017] After the performing magnetic resonance imaging on the imaging target using a hydrogen proton quantitative measurement sequence, further comprising:

[0018] When the echo data acquisition of the hydrogen proton is completed, a hydrogen proton image of the imaging target is reconstructed according to the acquired echo data of the hydrogen proton, a hydrogen proton quantitative image of the imaging target is obtained according to the hydrogen proton image of the imaging target, and a hydrogen proton contrast image of the imaging target is obtained according to the hydrogen proton quantitative image of the imaging target.

[0019] The hydrogen proton quantitative image of the imaging target comprises a hydrogen proton transverse relaxation time T2 image of the imaging target, or / and a hydrogen proton longitudinal relaxation time T1 image of the imaging target, or / and a hydrogen proton proton density PD image of the imaging target.

[0020] The hydrogen proton contrast image of the imaging target comprises a hydrogen proton T2 weighted image of the imaging target, or / and a hydrogen proton T1 weighted image of the imaging target, or / and a hydrogen proton black water T2 weighted image of the imaging target, or / and a hydrogen proton PD weighted image of the imaging target.

[0021] Before the hydrogen proton quantitative measurement sequence is used to perform magnetic resonance imaging on the imaging target, further comprising:

[0022] For each two adjacent slice excitations within a TR of the hydrogen proton quantitative measurement magnetic resonance imaging, a time interval from completion of a previous slice excitation and echo acquisition to start of a next slice excitation is calculated, the time interval is divided by a single TR value of the sodium ion magnetic resonance imaging, an obtained quotient is rounded down to obtain a first integer, and the first integer is taken as a set number of rounds.

[0023] And, the one or more rounds of sodium ion excitation and echo acquisition processes inserted into the sodium ion magnetic resonance imaging are one or more rounds of sodium ion excitation and echo acquisition processes of the set number of rounds of sodium ion magnetic resonance imaging.

[0024] The hydrogen proton quantitative measurement sequence is a dual-echo fast spin echo sequence, or a multi-echo fast spin echo sequence, or a multi-delay multi-echo sequence.

[0025] Before the hydrogen proton quantitative measurement sequence is used to perform magnetic resonance imaging on the imaging target, further comprising:

[0026] The system main frequency is set to a resonance frequency of the hydrogen proton.

[0027] The one or more rounds of sodium ion excitation and echo acquisition processes inserted into the sodium ion magnetic resonance imaging from completion of a previous slice excitation and echo acquisition to start of a next slice excitation comprise:

[0028] After the previous slice excitation and echo acquisition are completed, the system main frequency is switched to a resonance frequency of the sodium ion, one or more rounds of sodium ion excitation and echo acquisition processes are inserted into the sodium ion magnetic resonance imaging, and when the last round of sodium ion excitation and echo acquisition process is completed, the system main frequency is switched to the resonance frequency of the hydrogen proton.

[0029] A sodium ion magnetic resonance imaging device, comprising:

[0030] A scan triggering module, which triggers a hydrogen proton quantitative measurement sequence to perform magnetic resonance imaging on an imaging target;

[0031] A scan control module, which inserts one or more rounds of sodium ion excitation and echo acquisition processes of sodium ion magnetic resonance imaging between the completion of a previous slice excitation and echo acquisition and the start of a next slice excitation for any two adjacent slice excitations within a repetition time TR.

[0032] Before the scan triggering module triggers the hydrogen proton quantitative measurement sequence to perform magnetic resonance imaging on the imaging target, further comprising:

[0033] Performing one or more rounds of sodium ion excitation and echo acquisition processes.

[0034] The device further comprises a synthetic imaging module, which is configured to: when the echo data acquisition of the hydrogen protons is completed, reconstruct a hydrogen proton image of the imaging target according to the acquired echo data of the hydrogen protons, obtain a hydrogen proton quantitative map of the imaging target according to the hydrogen proton image of the imaging target, and obtain a hydrogen proton contrast map of the imaging target according to the hydrogen proton quantitative map of the imaging target.

[0035] Before the scan triggering module triggers the hydrogen proton quantitative measurement sequence to perform magnetic resonance imaging on the imaging target, further comprising:

[0036] For any two adjacent slice excitations within each TR of the hydrogen proton quantitative measurement magnetic resonance imaging, calculating a time interval between the completion of a previous slice excitation and echo acquisition and the start of a next slice excitation, dividing the time interval by a single TR value of the sodium ion magnetic resonance imaging, rounding down the quotient to obtain a first integer, and taking the first integer as a set number of rounds.

[0037] And the scan control module inserts one or more rounds of sodium ion excitation and echo acquisition processes of sodium ion magnetic resonance imaging, which is to insert the set number of rounds of sodium ion excitation and echo acquisition processes of sodium ion magnetic resonance imaging.

[0038] Before the scan triggering module triggers the hydrogen proton quantitative measurement sequence to perform magnetic resonance imaging on the imaging target, further comprising:

[0039] Setting a system main frequency to a resonance frequency of hydrogen protons;

[0040] The scan control module inserts one or more rounds of sodium ion excitation and echo acquisition processes of sodium ion magnetic resonance imaging between the completion of a previous slice excitation and echo acquisition and the start of a next slice excitation, comprising:

[0041] After the previous slice excitation and echo acquisition is completed, the system main frequency is switched to the resonance frequency of sodium ions, a round or multiple rounds of sodium ion excitation and echo acquisition process of sodium ion magnetic resonance imaging is inserted, and when the last round of sodium ion excitation and echo acquisition process is completed, the system main frequency is switched to the resonance frequency of hydrogen protons.

[0042] A medical imaging system, the system comprising the sodium ion magnetic resonance imaging device of any one of the above.

[0043] In the embodiment of the present application, when the hydrogen proton quantitative measurement sequence is used for MRI of the imaging target, for any two adjacent slice excitations within a TR, from the completion of the previous slice excitation and echo acquisition to the start of the next slice excitation, one or more rounds of sodium ion excitation and echo acquisition process of sodium ion MRI is inserted, so as to realize the interleaving of sodium ion imaging and hydrogen proton imaging within a TR, thereby improving the imaging efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0044] The preferred embodiments of the present application will be described in detail below with reference to the accompanying drawings, so that the above and other features and advantages of the present application can be more clearly understood by those skilled in the art, in which:

[0045] Figure 1 A flowchart of the sodium ion MRI method provided by an embodiment of the present application is shown in the figure;

[0046] Figure 2 A flowchart of the sodium ion MRI method provided by another embodiment of the present application is shown in the figure;

[0047] Figure 3 A process diagram of sodium ion MRI in an application example of the present application is shown in the figure;

[0048] Figure 4 A process diagram of sodium ion MRI in another application example of the present application is shown in the figure;

[0049] Figure 5 A process diagram of sodium ion MRI in another application example of the present application is shown in the figure;

[0050] Figure 6 A process diagram of sodium ion MRI in another application example of the present application is shown in the figure;

[0051] Figure 7 A structure diagram of the sodium ion MRI device provided by an embodiment of the present application is shown in the figure.

[0052] Among them, the reference signs are as follows:

[0053] DETAILED DESCRIPTION

[0054] In order to make the objectives, technical solutions and advantages of the present application clearer, the following further describes the present application in detail with examples.

[0055] Figure 1 A flow chart of the sodium ion MRI method provided by an embodiment of the present application is shown in FIG. 1. The specific steps are as follows: Figure 1

[0056] Step 101: Perform MRI on the imaging target by using a hydrogen proton quantitative measurement sequence.

[0057] The purpose of performing MRI on the imaging target by using the hydrogen proton quantitative measurement sequence is to obtain a hydrogen proton image of the imaging target, so as to further obtain a hydrogen proton quantitative image of the imaging target according to the hydrogen proton image of the imaging target. The hydrogen proton quantitative image of the imaging target can be, for example, a hydrogen proton T1 image of the imaging target, or / and a hydrogen proton T2 image of the imaging target, or / and a hydrogen proton PD image of the imaging target, etc. The hydrogen proton T1 image of the imaging target contains T1 values of hydrogen protons of each voxel point of the imaging target, the hydrogen proton T2 image of the imaging target contains T2 values of hydrogen protons of each voxel point of the imaging target, and the hydrogen proton PD image of the imaging target contains PD values of hydrogen protons of each voxel point of the imaging target.

[0058] In an optional embodiment, the hydrogen proton quantitative measurement sequence is a DE-TSE (Dual Echo-Turbo Spin Echo) sequence, or a ME-TSE (Multiple Echo-Turbo Spin Echo) sequence, or a MDME (Multiple-Delay-Multiple-Echo) sequence.

[0059] Step 102: For any two adjacent layer excitations within a TR, insert one or more rounds of sodium ion excitation and echo acquisition processes of the sodium ion MRI from the completion of the previous layer excitation and echo acquisition to the start of the next layer excitation.

[0060] Generally, a plurality of layers are subjected to layer excitation and echo acquisition within a TR. After the layer excitation and echo acquisition of a layer are completed, there is a period of time before the layer excitation of the next layer is performed, during which the hydrogen protons of the excited layer can relax. Since the resonance frequencies of sodium ions and hydrogen protons are different, the sodium ions can be excited and the echoes can be acquired during this period of time. The number of rounds of sodium ion excitation and echo acquisition during this period of time can be determined according to the length of this period of time and the length of time required for one round of sodium ion excitation and echo acquisition.

[0061] ​In practical application, after designing the sodium ion MRI sequence and the hydrogen proton quantitative measurement sequence, the number of sodium ion excitation and echo acquisition processes inserted between two adjacent slice excitations in a TR of the hydrogen proton quantitative measurement MRI can be determined. The specific determination process is as follows:

[0062] In an optional embodiment, before step 101, the method further comprises: for each TR of the hydrogen proton quantitative measurement MRI, calculating a time interval from completion of the previous slice excitation and echo acquisition to start of the next slice excitation, dividing the time interval by a single TR value of the sodium ion MRI, and rounding down the quotient to obtain a first integer, and taking the first integer as the set number of rounds.

[0063] In step 102, the one or more rounds of sodium ion excitation and echo acquisition processes of the sodium ion MRI are inserted as follows: the set number of rounds of sodium ion excitation and echo acquisition processes of the sodium ion MRI are inserted.

[0064] In an optional embodiment, after step 101, the method further comprises: when the hydrogen proton echo data acquisition is completed, reconstructing a hydrogen proton image of the imaging target according to the acquired hydrogen proton echo data, obtaining a hydrogen proton quantitative map of the imaging target according to the hydrogen proton image of the imaging target, and obtaining a hydrogen proton contrast map of the imaging target according to the hydrogen proton quantitative map of the imaging target. In an optional embodiment, the hydrogen proton quantitative map of the imaging target comprises a hydrogen proton T1 map of the imaging target, or / and a hydrogen proton T2 map of the imaging target, or / and a hydrogen proton PD map of the imaging target; and the hydrogen proton contrast map of the imaging target comprises a hydrogen proton T1 weighted map of the imaging target, or / and a hydrogen proton T2 weighted map of the imaging target, or / and a hydrogen proton black water T2 weighted map of the imaging target.

[0065] Wherein, the obtaining of the hydrogen proton quantitative map of the imaging target according to the hydrogen proton image of the imaging target, and the obtaining of the hydrogen proton contrast map of the imaging target according to the hydrogen proton quantitative map of the imaging target are both mature technologies and will not be described in detail.

[0066] In an optional embodiment, before step 101, the method further comprises: setting the system main frequency to the resonance frequency of the hydrogen proton.

[0067] In step 102, the one or more rounds of sodium ion excitation and echo acquisition processes of the sodium ion MRI are inserted as follows: after completion of the previous slice excitation and echo acquisition, the system main frequency is switched to the resonance frequency of the sodium ion, and the one or more rounds of sodium ion excitation and echo acquisition processes of the sodium ion MRI are inserted, and when the last round of sodium ion excitation and echo acquisition process is completed, the system main frequency is switched to the resonance frequency of the hydrogen proton.

[0068] The beneficial technical effects of the embodiments of the present application are as follows:

[0069] I. In the MRI of the imaging target by using the hydrogen proton quantitative measurement sequence, for any two adjacent layer excitations within a TR, a sodium ion MRI excitation and echo acquisition process is inserted between the completion of the previous layer excitation and echo acquisition and the start of the next layer excitation, so that sodium ion imaging and hydrogen proton imaging are staggered within a TR, thereby improving the imaging efficiency.

[0070] II. The hydrogen proton image of the imaging target is directly obtained through the hydrogen proton imaging process, and then various hydrogen proton quantitative images of the imaging target such as a hydrogen proton T1 image, a hydrogen proton T2 image, and a hydrogen proton PD image can be obtained according to the hydrogen proton image. Various hydrogen proton contrast images of the imaging target such as a hydrogen proton T1 weighted image, a hydrogen proton T2 weighted image, and a hydrogen proton black water T2 weighted image can be obtained according to the hydrogen proton quantitative images, so that various hydrogen proton contrast images of the imaging target can be obtained at one time through one hydrogen proton scanning process, the influence of motion on the acquisition of various hydrogen proton contrast and sodium ion imaging is reduced, and the consistency of various hydrogen proton contrast and sodium ion images is improved.

[0071] In the above embodiments, the hydrogen proton imaging is first started, and the sodium ion excitation and echo acquisition process is inserted between the completion of the previous layer excitation and echo acquisition and the start of the next layer excitation of the adjacent two layer excitations in the hydrogen proton imaging. In actual application, the sodium ion imaging can also be first started, that is, before step 101, further comprising: performing one or more sodium ion excitation and echo acquisition processes.

[0072] Figure 2 The flowchart of the sodium ion MRI method provided by another embodiment of the present application is shown in FIG. 2. Figure 2 The specific steps are as follows:

[0073] Step 201: For the adjacent two layer excitations within each TR of the hydrogen proton quantitative measurement MRI, the time interval between the completion of the previous layer excitation and echo acquisition and the start of the next layer excitation is calculated, the time interval is divided by the single TR value of the sodium ion MRI, the obtained quotient is rounded down to obtain a first integer, and the first integer is taken as the set number of rounds.

[0074] Step 202: The system main frequency is set to the resonance frequency of the hydrogen proton, and the MRI of the imaging target is started by using the hydrogen proton quantitative measurement sequence.

[0075] In an optional embodiment, the hydrogen proton quantitative measurement sequence is a DE-TSE sequence, or a ME-TSE sequence, or a MDME sequence.

[0076] Step 203: for any two adjacent layer excitations within a TR, after the previous layer excitation and echo acquisition are completed, the system main frequency is switched to the resonance frequency of sodium ions, a set number of sodium ion excitation and echo acquisition processes of sodium ion MRI are inserted, and when the last round of sodium ion excitation and echo acquisition process is completed, the system main frequency is switched to the resonance frequency of hydrogen protons.

[0077] Step 204: when the echo data acquisition of hydrogen protons is completed, the hydrogen proton image of the imaging target is reconstructed according to the acquired echo data of hydrogen protons, the hydrogen proton quantitative map of the imaging target is obtained according to the hydrogen proton image of the imaging target, and the hydrogen proton contrast map of the imaging target is obtained according to the hydrogen proton quantitative map of the imaging target.

[0078] In an optional embodiment, the hydrogen proton quantitative map of the imaging target includes: a hydrogen proton T1 map of the imaging target, or / and a hydrogen proton T2 map of the imaging target, or / and a hydrogen proton PD map of the imaging target; and the hydrogen proton contrast map of the imaging target includes: a hydrogen proton T1 weighted map of the imaging target, or / and a hydrogen proton T2 weighted map of the imaging target, or / and a hydrogen proton black water T2 weighted map of the imaging target.

[0079] In the above embodiment, when the hydrogen proton quantitative measurement sequence is used for MRI of the imaging target, for any two adjacent layer excitations within a TR, from the completion of the previous layer excitation and echo acquisition to the start of the next layer excitation, one or more rounds of sodium ion excitation and echo acquisition processes of sodium ion MRI are inserted, so that sodium ion imaging and hydrogen proton imaging are interleaved within a TR, thereby improving the imaging efficiency; and the hydrogen proton image with a shorter imaging time is directly acquired, and then the hydrogen proton quantitative map is obtained according to the hydrogen proton image, and the hydrogen proton contrast map is calculated according to the hydrogen proton quantitative map, thereby further reducing the imaging time and improving the imaging efficiency; and the embodiment of the present application does not need to change any hardware, and the cost is very low.

[0080] In the above embodiment, the hydrogen proton imaging is first started, and the excitation and echo acquisition process of sodium ions is inserted from the completion of the previous layer excitation and echo acquisition of the adjacent two layer excitations of the hydrogen proton imaging to the start of the next layer excitation. In actual application, the sodium ion imaging can also be first started, that is, between step 201 and step 202, further comprising: setting the system main frequency to the resonance frequency of sodium ions, and performing a set number of sodium ion excitation and echo acquisition processes of sodium ion MRI; and in step 202, setting the system main frequency to the resonance frequency of hydrogen protons, comprising: when the last round of sodium ion excitation and echo acquisition process is completed, the system main frequency is switched to the resonance frequency of hydrogen protons.

[0081] Figure 3Fig. 1 is a process diagram of sodium ion MRI in an application example of the present application. In this example, hydrogen proton MRI is first started, and the hydrogen proton quantitative measurement sequence adopts DE-TSE sequence. Wherein:

[0082] 31 is a process of excitation and echo acquisition of layer m in a TR of hydrogen proton MRI, wherein 311 is an excitation pulse, 312 is a first group of echo trains, and 313 is a second group of echo trains; 312 and 313 each contain multiple echo trains, and 312 and 313 contain the same number of echo trains;

[0083] 32 is a process of excitation and echo acquisition of layer n in a TR of hydrogen proton MRI, wherein 321 is an excitation pulse, 322 is a first group of echo trains, and 323 is a second group of echo trains; 322 and 323 each contain multiple echo trains, and 322 and 323 contain the same number of echo trains, and 322, 323, 312, and 313 contain the same number of echo trains;

[0084] Figure 3 An example of multiple echo trains contained in 312 is given, wherein 3121 is a first echo train, 3122 is a first echo, 3123 is a second echo train, and 3124 is a second echo; here, layer m and layer n are two adjacent excited layers in a TR of hydrogen proton MRI; as shown in Fig. 2, the TR of hydrogen proton MRI is TR1; Figure 3

[0085] 33 and 34 are excitation and acquisition processes of sodium ion imaging, 331 and 341 are excitation pulses, and 332 and 342 are echoes; as shown in Fig. 3, the TR of sodium ion MRI is TR2; Figure 3

[0086] 351 and 352 are a hydrogen proton T2 map and a hydrogen proton PD map of the imaging target, respectively, 353 is a hydrogen proton T2 weighted map of the imaging target calculated according to 351 and 352, and 354 is a sodium ion image of the imaging target obtained by the present sodium ion MRI.

[0087] Figure 4 Fig. 4 is a process diagram of sodium ion MRI in another application example of the present application. In this example, sodium ion MRI is first started, and the hydrogen proton quantitative measurement sequence adopts DE-TSE sequence. Wherein:

[0088] ​​41, 42, 43 are excitation and acquisition processes of sodium ion imaging, 411, 421, 431 are excitation pulses, and 412, 422, 432 are echoes; as shown in Figure 4 TR of sodium ion MRI is TR2;

[0089] 44 is a process of excitation and echo acquisition of layer m in a current TR of hydrogen proton MRI, 441 is an excitation pulse, 442 is a first group of refocusing pulse and echo pairs, and 443 is a second group of refocusing pulse and echo pairs; 442 and 443 respectively contain multiple pairs of refocusing pulses and echoes, and 442 and 443 contain the same number of pairs of refocusing pulses and echoes;

[0090] 45 is a process of excitation and echo acquisition of layer n in a current TR of hydrogen proton MRI, 451 is an excitation pulse, 452 is a first group of refocusing pulse and echo pairs, and 453 is a second group of refocusing pulse and echo pairs; 452 and 453 respectively contain multiple pairs of refocusing pulses and echoes, and 452, 453, 442, and 443 contain the same number of pairs of refocusing pulses and echoes;

[0091] Figure 4 An example of multiple pairs of refocusing pulses and echoes contained in 442 is given, wherein 4421 is a first refocusing pulse, 4422 is a first echo, 4423 is a second refocusing pulse, and 4424 is a second echo, 4421 and 4422 are a first pair of refocusing pulse and echo, and 4423 and 4424 are a second pair of refocusing pulse and echo;

[0092] Here, layer m and layer n are two adjacent excited layers in a current TR of hydrogen proton MRI; as shown in Figure 4 TR of hydrogen proton MRI is TR1;

[0093] 461 and 462 are hydrogen proton T2 images and hydrogen proton PD images of the imaging target respectively, 463 is a hydrogen proton T2 weighted image of the imaging target calculated according to 461 and 462, and 464 is a sodium ion image of the imaging target obtained by the current sodium ion MRI.

[0094] Figure 5 is a process schematic diagram of sodium ion MRI in another application example of the present application. In this example, hydrogen proton MRI is started first, and the hydrogen proton quantitative measurement sequence adopts an MDME sequence. Among them:

[0095] 51 is an inversion recovery (or saturation recovery) excitation of layer i and excitation and echo acquisition of layer m in a current TR of hydrogen proton MRI, 511 is an inversion recovery (or saturation recovery) pulse of layer i, 512 is an excitation pulse of layer m, 513 is a first set of refocusing pulses and echo pairs of layer m, and 514 is a second set of refocusing pulses and echo pairs of layer m; 513 and 514 each contain multiple pairs of refocusing pulses and echoes, and 513 and 514 contain the same number of pairs of refocusing pulses and echoes; wherein 51 contains multiple sets of refocusing pulses and echo pairs of layer m;

[0096] 52 is an inversion recovery (or saturation recovery) excitation of layer j and excitation and echo acquisition of layer n in a current TR of hydrogen proton MRI, 521 is an inversion recovery (or saturation recovery) pulse of layer j, 522 is an excitation pulse of layer n, 523 is a first set of refocusing pulses and echo pairs of layer n, and 524 is a second set of refocusing pulses and echo pairs of layer n; 523 and 524 each contain multiple pairs of refocusing pulses and echoes, and 523, 524, 513, and 514 contain the same number of pairs of refocusing pulses and echoes; wherein 52 contains multiple sets of refocusing pulses and echo pairs of layer n;

[0097] Figure 5 An example of multiple pairs of refocusing pulses and echoes contained in 513 is given, wherein 5131 is a first refocusing pulse, 5132 is a first echo, 5133 is a second refocusing pulse, and 5134 is a second echo; 5131 and 5132 form a first pair of refocusing pulse and echo, and 5133 and 5134 form a second pair of refocusing pulse and echo;

[0098] Here, layer m and layer n are two adjacent layers excited in a current TR of hydrogen proton MRI; as shown in Figure 5 The TR of hydrogen proton MRI is TR1; in addition, i-j = m-n;

[0099] 53 and 54 are excitation and acquisition processes of sodium ion imaging, 531 and 541 are excitation pulses, and 532 and 542 are echoes;

[0100] 551, 552, and 553 are hydrogen proton T2 images, hydrogen proton PD images, and hydrogen proton T1 images of the imaging target, respectively, 554 is a hydrogen proton T2 weighted image of the imaging target calculated according to 551 and 552, 555 is a hydrogen proton T1 weighted image of the imaging target calculated according to 551, 552, and 553, 556 is a black water T2 weighted image of the imaging target calculated according to 551, 552, and 553, and 557 is a sodium ion image of the imaging target obtained by the current sodium ion MRI.

[0101] Figure 6A process diagram of sodium ion MRI is given as another application example of the present application. In this example, sodium ion MRI is started first, and the hydrogen proton quantitative measurement sequence adopts MDME sequence. In which:

[0102] 61, 62, 63 are excitation and acquisition processes of sodium ion imaging, 611, 621, 631 are excitation pulses, and 612, 622, 632 are echoes; as shown in the figure, the TR of sodium ion MRI is TR2; Figure 6

[0103] 64 is a process of inversion recovery (or saturation recovery) excitation of layer i and excitation and echo acquisition of layer m in one TR of hydrogen proton MRI, 641 is the inversion recovery (or saturation recovery) pulse of layer i, 642 is the excitation pulse of layer m, 643 is the first group of refocusing pulses and echo pairs of layer m, and 644 is the second group of refocusing pulses and echo pairs of layer m; 643 and 644 respectively contain multiple pairs of refocusing pulses and echoes, and the number of refocusing pulses and echo pairs contained in 643 and 644 is the same; wherein, 64 contains multiple groups of refocusing pulses and echo pairs of layer m;

[0104] 65 is a process of inversion recovery (or saturation recovery) excitation of layer j and excitation and echo acquisition of layer n in the current TR of hydrogen proton MRI, 651 is the inversion recovery (or saturation recovery) pulse of layer j, 652 is the excitation pulse of layer n, 653 is the first group of refocusing pulses and echo pairs of layer n, and 654 is the second group of refocusing pulses and echo pairs of layer n; 653 and 654 respectively contain multiple pairs of refocusing pulses and echoes, and the number of refocusing pulses and echo pairs contained in 653, 654, 643, and 644 is the same; wherein, 65 contains multiple groups of refocusing pulses and echo pairs of layer n; as shown in the figure, the TR of hydrogen proton MRI is TR1; Figure 6

[0105] Figure 6 An example of multiple pairs of refocusing pulses and echoes contained in 643 is given, wherein 6431 is the first refocusing pulse, 6432 is the first echo, 6433 is the second refocusing pulse, and 6434 is the second echo, 6431 and 6432 are the first refocusing pulse and echo pair, and 6433 and 6434 are the second refocusing pulse and echo pair;

[0106] Here, layer m and layer n are two adjacent excitation layers in the current TR of hydrogen proton MRI; as shown in the figure, the TR of hydrogen proton MRI is TR1; in addition, i-j=m-n; Figure 6

[0107] ​​​661, 662, 663 are respectively hydrogen proton T2 image, hydrogen proton PD image, hydrogen proton T1 image of the imaging target, 664 is a hydrogen proton T2 weighted image of the imaging target calculated according to 661 and 662, 665 is a hydrogen proton T1 weighted image of the imaging target calculated according to 661, 662 and 663, 666 is a black water T2 weighted image of the imaging target calculated according to 661, 662 and 663, and 667 is a sodium ion image of the imaging target obtained by the present sodium ion MRI.

[0108] Figure 7 A structure schematic diagram of the sodium ion MRI device 70 provided by an embodiment of the present application is shown in FIG. 7. As shown in the figure, the device mainly comprises a scan triggering module 71, a scan control module 72 and a synthetic imaging module 73, wherein: Figure 7

[0109] The scan triggering module 71 adopts a hydrogen proton quantitative measurement sequence to perform MRI on the imaging target.

[0110] The scan control module 72, for any two adjacent layer excitations within a TR, inserts one or more rounds of sodium ion excitation and echo acquisition process of sodium ion MRI from the completion of the previous layer excitation and echo acquisition to the start of the next layer excitation.

[0111] The synthetic imaging module 73, when the echo data acquisition of the hydrogen proton is completed, reconstructs a hydrogen proton image of the imaging target according to the acquired echo data of the hydrogen proton, obtains a hydrogen proton quantitative image of the imaging target according to the hydrogen proton image of the imaging target, and obtains a hydrogen proton contrast image of the imaging target according to the hydrogen proton quantitative image of the imaging target.

[0112] In an optional embodiment, the hydrogen proton quantitative image of the imaging target obtained by the synthetic imaging module 73 comprises a hydrogen proton T1 image of the imaging target, or / and a hydrogen proton T2 image of the imaging target, or / and a hydrogen proton PD image of the imaging target.

[0113] The hydrogen proton contrast image of the imaging target obtained by the synthetic imaging module 73 comprises a hydrogen proton T1 weighted image of the imaging target, or / and a hydrogen proton T2 weighted image of the imaging target, or / and a hydrogen proton black water T2 weighted image of the imaging target.

[0114] In an optional embodiment, before the scan triggering module 71 adopts the hydrogen proton quantitative measurement sequence to perform MRI on the imaging target, it is further used for: for any two adjacent layer excitations within a TR of the hydrogen proton quantitative measurement MRI, calculating a time interval from the completion of the previous layer excitation and echo acquisition to the start of the next layer excitation, dividing the time interval by a single TR value of the sodium ion MRI, rounding down the quotient to obtain a first integer, and taking the first integer as the set number of rounds.

[0115] ​The scan control module 72 inserts one or more rounds of sodium ion excitation and echo acquisition processes of the sodium ion MRI into the above-mentioned set number of rounds of sodium ion excitation and echo acquisition processes of the sodium ion MRI.

[0116] In an optional embodiment, before the scan trigger module 71 performs MRI on the imaging target by using the hydrogen proton quantitative measurement sequence, the method further comprises: setting the system main frequency to the resonance frequency of the hydrogen proton.

[0117] The scan control module 72 inserts one or more rounds of sodium ion excitation and echo acquisition processes of the sodium ion MRI into the above-mentioned set number of rounds of sodium ion excitation and echo acquisition processes of the sodium ion MRI from the completion of the previous layer excitation and echo acquisition to the start of the next layer excitation, including: after the completion of the previous layer excitation and echo acquisition, switching the system main frequency to the resonance frequency of the sodium ion, inserting one or more rounds of sodium ion excitation and echo acquisition processes of the sodium ion MRI, and when the last round of sodium ion excitation and echo acquisition process is completed, switching the system main frequency to the resonance frequency of the hydrogen proton.

[0118] The embodiment of the present application also provides a medical imaging system, which comprises the sodium ion MRI device 70 as described in any of the above-mentioned embodiments.

[0119] The embodiment of the present application also provides a computer program product, which comprises a computer program or instructions, and the computer program or instructions are executed by a processor to implement the steps of the sodium ion MRI method as described in any of the above-mentioned embodiments.

[0120] The embodiment of the present application also provides a computer readable storage medium, which stores instructions, and the instructions are executed by a processor to implement the steps of the sodium ion MRI method as described above. In practical applications, the computer readable medium can be included in the above-mentioned devices / apparatus / systems, or can exist separately without being assembled into the devices / apparatus / systems. The instructions stored in the computer readable storage medium are executed by the processor to implement the steps of the sodium ion MRI method as described above.

[0121] The embodiment of the present application also provides an electronic device. The electronic device can include a processor with one or more processing cores, a memory with one or more computer readable storage media, and a computer program stored in the memory and executable on the processor. When the program of the memory is executed, the above-mentioned sodium ion MRI method can be implemented.

[0122] Those skilled in the art can understand that the features described in various embodiments and / or claims of the present application can be combined and / or integrated in various combinations and / or integrations, even if such combinations or integrations are not explicitly described in the present application. In particular, the features described in various embodiments and / or claims of the present application can be combined and / or integrated in various combinations and / or integrations without departing from the spirit and teachings of the present application, and all such combinations and / or integrations fall within the scope of the present application.

[0123] The principles and implementation manners of the present application are described herein by using specific embodiments, and the above embodiment descriptions are only used to help understand the method of the present application and its core ideas, and are not used to limit the present application. For those skilled in the art, any modification, equivalent replacement, improvement, etc. can be made on the specific implementation manners and application ranges according to the ideas, spirits and principles of the present application, and all such modifications, equivalent replacements, improvements, etc. shall be included in the protection scope of the present application.

Claims

1. A sodium ion magnetic resonance imaging method, characterized by, The method comprises: For adjacent two layer excitations in each TR of the hydrogen proton quantitative measurement MRI, a time interval from completion of the previous layer excitation and echo acquisition to start of the next layer excitation is calculated, the time interval is divided by a single TR value of the sodium ion MRI, a first integer is obtained by rounding down the quotient, and the first integer is taken as a set number of rounds; Magnetic resonance imaging of the imaging target is performed using a hydrogen proton quantitative measurement sequence; For adjacent two layer excitations in any repetition time TR, a set number of rounds of sodium ion excitation and echo acquisition processes of sodium ion magnetic resonance imaging are inserted from completion of the previous layer excitation and echo acquisition to start of the next layer excitation. When the echo data acquisition of the hydrogen proton is completed, a hydrogen proton image of the imaging target is reconstructed according to the acquired echo data of the hydrogen proton, a hydrogen proton quantitative map of the imaging target is obtained according to the hydrogen proton image of the imaging target, and a hydrogen proton contrast map of the imaging target is obtained according to the hydrogen proton quantitative map of the imaging target.

2. The method of claim 1, wherein, Before the magnetic resonance imaging of the imaging target is performed using the hydrogen proton quantitative measurement sequence, the method further comprises: One or more rounds of sodium ion excitation and echo acquisition processes are performed.

3. The method of claim 1, wherein, The hydrogen proton quantitative map of the imaging target comprises a hydrogen proton transverse relaxation time T2 map of the imaging target, or / and a hydrogen proton longitudinal relaxation time T1 map of the imaging target, or / and a hydrogen proton proton density PD map of the imaging target; The hydrogen proton contrast map of the imaging target comprises a hydrogen proton T2 weighted map of the imaging target, or / and a hydrogen proton T1 weighted map of the imaging target, or / and a hydrogen proton black water T2 weighted map of the imaging target, or / and a hydrogen proton PD weighted map of the imaging target.

4. The method of claim 1, wherein, The hydrogen proton quantitative measurement sequence is a dual-echo fast spin echo sequence, or a multi-echo fast spin echo sequence, or a multi-delay multi-echo sequence.

5. The method of claim 1, wherein, Before the magnetic resonance imaging of the imaging target is performed using the hydrogen proton quantitative measurement sequence, the method further comprises: The system main frequency is set to the resonance frequency of the hydrogen proton; The one or more rounds of sodium ion excitation and echo acquisition processes of the sodium ion magnetic resonance imaging inserted from completion of the previous layer excitation and echo acquisition to start of the next layer excitation comprise: After completion of the previous layer excitation and echo acquisition, the system main frequency is switched to the resonance frequency of the sodium ion, one or more rounds of sodium ion excitation and echo acquisition processes of the sodium ion magnetic resonance imaging are inserted, and when the last round of sodium ion excitation and echo acquisition process is completed, the system main frequency is switched to the resonance frequency of the hydrogen proton.

6. A sodium ion magnetic resonance imaging apparatus, characterized by, The device comprises: A scan trigger module, for adjacent two layer excitations in each TR of the hydrogen proton quantitative measurement magnetic resonance imaging, a time interval from completion of the previous layer excitation and echo acquisition to start of the next layer excitation is calculated, the time interval is divided by a single TR value of the sodium ion magnetic resonance imaging, a first integer is obtained by rounding down the quotient, and the first integer is taken as a set number of rounds; and magnetic resonance imaging of the imaging target is performed using a hydrogen proton quantitative measurement sequence. The scan control module inserts the set number of sodium ion excitation and echo acquisition processes of sodium ion magnetic resonance imaging between the completion of the previous layer excitation and echo acquisition and the start of the next layer excitation for any two adjacent layer excitations within a repetition time TR. The synthetic imaging module is configured to: when the echo data acquisition of the hydrogen protons is completed, reconstruct a hydrogen proton image of the imaging target according to the acquired echo data of the hydrogen protons, obtain a hydrogen proton quantitative map of the imaging target according to the hydrogen proton image of the imaging target, and obtain a hydrogen proton contrast map of the imaging target according to the hydrogen proton quantitative map of the imaging target.

7. The apparatus of claim 6, wherein, Before the scan trigger module performs magnetic resonance imaging on the imaging target by using the hydrogen proton quantitative measurement sequence, the method further includes: performing one or more rounds of sodium ion excitation and echo acquisition processes.

8. The apparatus of claim 6, wherein, Before the scan trigger module performs magnetic resonance imaging on the imaging target by using the hydrogen proton quantitative measurement sequence, the method further includes: setting the system main frequency to the resonance frequency of the hydrogen protons; The scan control module inserts one or more rounds of sodium ion excitation and echo acquisition processes of sodium ion magnetic resonance imaging between the completion of the previous layer excitation and echo acquisition and the start of the next layer excitation, including: after the completion of the previous layer excitation and echo acquisition, switching the system main frequency to the resonance frequency of the sodium ions, inserting one or more rounds of sodium ion excitation and echo acquisition processes of sodium ion magnetic resonance imaging, and when the last round of sodium ion excitation and echo acquisition process is completed, switching the system main frequency to the resonance frequency of the hydrogen protons.

9. A medical imaging system, characterized by The system includes the sodium ion magnetic resonance imaging device according to any one of claims 6 to 8.

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