A test device and test method for multi-nuclear magnetic resonance radio frequency coils

Abstract

The application discloses a kind of for multi-nuclear magnetic resonance radio frequency coil testing device, and a kind of for multi-nuclear magnetic resonance radio frequency coil testing method, the application is tested by using the magnetic resonance signal that analog MR signal generating source analog production measured sample generates after radio frequency pulse excitation to replace actual sample, not only can reduce cost and simplify operation, reduce the dependence on sample, also make the test process more controllable and repeatable, the application can effectively optimize the performance of the radio frequency coil to be measured, ensure that high-quality image is obtained in actual imaging process;The application can adapt to different imaging needs and environmental conditions, there are different testing methods under different test environments;Using switch to switch transmission and reception test, so that the transmission function of the coil to be measured can be tested under the same test device, and the receiving function of the radio frequency coil to be measured can also be tested, improve the efficiency of test.

Description

Technical Field

[0001] This invention belongs to the field of magnetic resonance imaging technology, specifically relating to a testing device for multi-core magnetic resonance radio frequency coils, and also to a testing method for multi-core magnetic resonance radio frequency coils. It is suitable for completing the transmission and reception function tests of the radio frequency coil under test in a single scan, and can also measure and evaluate transmission efficiency, reception efficiency, and reception sensitivity. Background Technology

[0002] Magnetic Resonance Imaging (MRI) is a widely used medical imaging technique that provides high-resolution images of soft tissues. The basic principle of MRI is based on the phenomenon of nuclear magnetic resonance. By applying a strong magnetic field and radio frequency (RF) pulses, the atomic nuclei in the sample resonate, generating signals that can be used for imaging. These released signals (i.e., freely inductively decaying signals) are then captured by a receiving coil and converted into an image. The performance of the RF coil directly affects the quality and accuracy of the imaging; therefore, a malfunction in the RF coil may lead to decreased image quality or even prevent imaging altogether.

[0003] The testing of existing multi-nuclear magnetic resonance radio frequency coils, whether on an MRI scanner or a workbench, typically relies on real samples. In some cases, especially when researching novel imaging coils or testing the performance of radio frequency coils, such as testing multi-nuclear magnetic resonance radio frequency coils, the lack of suitable samples can lead to difficulties in imaging testing. Sample acquisition and processing usually involve high costs, and the process of processing real samples often requires specialized equipment and technicians, thus increasing operational complexity and time costs, among other limitations. For example, in the testing of hyperpolarized xenon (HXN) coils... 129 In Xe imaging, hyperpolarization processing is usually required under specific conditions to improve... 129 The signal strength of Xe is affected by the high production and storage costs of hyperpolarized xenon gas. If the sole purpose is to test coil performance, the overall cost increases significantly when multiple imaging tests are required, making the acquisition process complex and time-consuming. On the other hand, compared to... 1 Compared to H, 23 Na、 31 The magnetic moments and gyromagnetic ratios of atomic nuclei such as phosphorus are small, and their content in the human body is low, resulting in weak magnetic resonance signals. If the coil sensitivity is not high enough, the signal often cannot be acquired, making coil testing difficult and lacking in the ability to detect these signals. 23 Na、 31 Testing methods for P-type multi-core magnetic resonance radio frequency coils. Therefore, it is essential to use analog signal sources for performance evaluation and optimization of multi-core magnetic resonance radio frequency coils. This allows for coil testing without relying on real samples, reducing costs, simplifying operations, and improving testing efficiency and repeatability.23 Na、 31 The testing of P-type multinuclear magnetic resonance radio frequency coils provides a new method. Summary of the Invention

[0004] The purpose of this invention is to address the aforementioned problems in the prior art by providing a testing device for multi-core magnetic resonance radio frequency coils, and also to provide a testing method for multi-core magnetic resonance radio frequency coils.

[0005] The above-mentioned objectives of the present invention are achieved by the following technical means:

[0006] A testing device for multi-core magnetic resonance radio frequency coils includes a radio frequency coil under test, a switching switch, an attenuator, a signal measurement module, an analog MR signal generator, a coaxial cable, and a small radio frequency probe. The radio frequency coil under test is provided with a coil connector. The small radio frequency probe is placed in a designated area of ​​the radio frequency coil under test. The switching switch includes a control input port, a probe connection port, a radio frequency input port, and a radio frequency output port. The small radio frequency probe is connected to the probe connection port of the switching switch. The input end of the attenuator is connected to the radio frequency output port of the switching switch. The output end of the attenuator is connected to the input end of the signal measurement module. The output end of the analog MR signal generator is connected to the radio frequency input port of the switching switch via the coaxial cable.

[0007] It also includes a data acquisition module, which acquires the magnetic resonance signal received when the radio frequency coil under test is in the receiving state, obtains the received signal, and records and displays the waveform of the received signal;

[0008] Replace the reference coil with the RF coil under test to perform relative measurement of the RF coil under test.

[0009] A testing method for multi-core magnetic resonance radio frequency coils, utilizing a testing apparatus for multi-core magnetic resonance radio frequency coils as described above, includes the following steps:

[0010] Step 1: Acquire the transmission control signal and radio frequency pulse signal, perform a transmission function test on the radio frequency coil under test, and determine whether the transmission function of the radio frequency coil under test is normal.

[0011] Step 2: Obtain the receive control signal, perform a receive function test on the RF coil under test, and determine whether the receive function of the RF coil under test is normal.

[0012] Step 3: Change the pulse voltage VT0 of the radio frequency pulse signal, measure the transmission efficiency of the radio frequency coil under test, replace the radio frequency coil under test with the reference coil, and measure the relative transmission efficiency of the radio frequency coil under test.

[0013] Step 4: Change the amplitude VR0 of the magnetic resonance signal output by the analog MR signal generator, measure the receiving efficiency and receiving sensitivity of the tested RF coil, replace the tested RF coil with the reference coil, and measure the relative receiving efficiency and relative receiving sensitivity of the tested RF coil.

[0014] As described above, step 1 specifically includes the following steps:

[0015] Step 1.1: Input the transmission control signal to the switching switch and the signal measurement module, and input the radio frequency pulse signal to the radio frequency coil under test. After receiving the radio frequency pulse signal, the radio frequency coil under test is excited to generate a B1+ field signal. After the switching switch receives the transmission control signal, the probe connection port of the switching switch and the radio frequency output port are connected, and the small radio frequency probe is in the receiving state. After receiving the B1+ field signal transmitted by the radio frequency coil under test, the small radio frequency probe inputs it to the signal measurement module. The signal measurement module displays and records the waveform of the B1+ field signal received by the small radio frequency probe.

[0016] Step 1.2: Observe the B1+ field signal waveform to determine whether the transmission function of the tested RF coil is normal, including: determining whether the amplitude change of the B1+ field signal waveform is within the set range, and whether the timing of the RF pulse signal waveform is consistent with the timing of the B1+ field signal waveform.

[0017] As described above, step 2 specifically includes the following steps:

[0018] Step 2.1: Input the receiving control signal to the switching switch and the simulated MR signal generator. After the switching switch receives the receiving control signal, the probe connection port of the switching switch and the radio frequency input port are connected. After the simulated MR signal generator receives the receiving control signal, it simulates and generates a magnetic resonance signal and transmits it to the small radio frequency probe. Then, the magnetic resonance signal radiated by the small radio frequency probe is received by the radio frequency coil under test, and then the received signal is acquired by the acquisition module. The received signal waveform is recorded and displayed.

[0019] Step 2.2: Analyze the received signal to determine whether the receiving function of the tested RF coil is normal: observe whether there is obvious distortion or irregular fluctuation in the received signal waveform, and check whether the amplitude and noise of the received signal waveform are within the set range.

[0020] As described above, step 3, measuring the emission efficiency of the RF coil under test, specifically includes the following steps:

[0021] Step 3.1: Change the pulse voltage VT0 of the radio frequency pulse signal, repeat step 1.1, receive and display the B1+ field signal waveform through the signal measurement module, obtain the amplitude V1 of the B1+ field signal waveform based on the B1+ field signal waveform, and calculate the ratio V1 / VT0.

[0022] Step 3.2: Replace the RF coil under test with the reference coil, and then repeat step 3.1 to obtain the transmission efficiency of the reference coil. Then calculate the ratio of the transmission efficiency of the RF coil under test to that of the reference coil under the same test conditions.

[0023] As described above, step 4 of measuring the receiving sensitivity of the RF coil under test specifically includes the following steps:

[0024] Step 4.1: Change the amplitude VR0 of the magnetic resonance signal output by the analog MR signal generator, repeat step 2.1, the acquisition module acquires and displays the received signal waveform, obtains the amplitude VR1 of the received signal waveform, and calculates the ratio VR1 / VR0.

[0025] Step 4.2: Reduce the amplitude VR0 of the magnetic resonance signal output by the analog MR signal generator, and obtain the output amplitude VR0min of the analog MR signal generator corresponding to the smallest received signal that the acquisition module can distinguish;

[0026] Step 4.3: Replace the RF coil under test with the reference coil, and then repeat steps 4.1 and 4.2 to obtain the receiving efficiency of the reference coil. Then calculate the ratio of the receiving efficiency of the RF coil under test to that of the reference coil under the same test conditions, as well as the ratio of VR0min of the RF coil under test to that of the reference coil.

[0027] A testing method for multi-core magnetic resonance radio frequency coils, when using a magnetic resonance spectrometer to generate radio frequency pulse signals, transmit control signals, and receive control signals, further includes a first signal adapter. The first signal adapter includes an input port and three output ports. The input port of the first signal adapter is connected to the scanning bed of the magnetic resonance spectrometer, and the three output ports of the first signal adapter are respectively connected to the control input port of a switching switch, a signal measurement module, and an analog MR signal generator. The radio frequency coil under test is placed on the scanning bed of the magnetic resonance spectrometer and connected to the scanning bed of the magnetic resonance spectrometer.

[0028] The radio frequency pulse signal, the transmit control signal, and the receive control signal are generated in the following way: a pulse sequence is run on the magnetic resonance imaging (MRI) scanner. When the pulse sequence is running in the transmit state, the MRI scanner generates a radio frequency pulse signal, and the MRI scanner bed generates a transmit control signal; when the pulse sequence is running in the receive state, the MRI scanner bed generates a receive control signal.

[0029] The acquisition module is a magnetic resonance spectrometer. The radio frequency coil under test receives the magnetic resonance signal radiated by the small radio frequency probe and sends it to the magnetic resonance spectrometer through the coil connector. The magnetic resonance spectrometer acquires the received signal and records and displays the waveform of the received signal.

[0030] A testing method for multi-core magnetic resonance radio frequency coils, when using an analog transmit and receive control signal source to generate transmit control signals and receive control signals, and using a radio frequency pulse source to generate radio frequency pulse signals, further includes a signal adapter board and a second signal adapter. The signal adapter board includes a first input port, a second input port, a first output port, and a second bidirectional port. The second signal adapter includes a first output port, a second output port, a third output port, a fourth output port, and a fifth output port. The first input port of the signal adapter board is connected to the output port of the radio frequency pulse source. The second input port of the signal adapter board is connected to the output port of the analog transmit and receive control signal source. The first output port of the signal adapter board is connected to the first input port of the second signal adapter. The second bidirectional port of the signal adapter board is connected to the coil connector. The first output port of the second signal adapter is connected to the control input port of a switch. The second output port of the second signal adapter is connected to a signal measurement module. The third output port of the second signal adapter is connected to an analog MR signal generator. The fourth output port of the second signal adapter is connected to the radio frequency pulse source. The fifth output port of the second signal adapter is connected to an independent signal input channel of the signal measurement module.

[0031] The radio frequency pulse signal, transmit control signal, and receive control signal are generated in the following ways: a simulated transmit and receive control signal source simulates and generates the transmit control signal, and sends the transmit control signal to the switching switch, the signal measurement module, and the radio frequency pulse source. After receiving the transmit control signal, the radio frequency pulse source generates the radio frequency pulse signal; the simulated transmit and receive control signal source simulates and generates the receive control signal.

[0032] The acquisition module is a signal measurement module. The radio frequency coil under test receives the magnetic resonance signal radiated by the small radio frequency probe and then transmits it to the signal adapter board. It is then sent to the signal measurement module through the second signal adapter. The signal measurement module acquires the received signal and records and displays the waveform of the received signal.

[0033] Compared with the prior art, the present invention has the following advantages:

[0034] (1) The present invention uses a simulated MR signal generator to emit simulated signals to replace actual samples for testing. This not only reduces costs and simplifies operation, but also reduces dependence on samples. It also makes the testing process more controllable and repeatable. The present invention can effectively optimize the performance of the tested RF coil and ensure that high-quality images are obtained in the actual imaging process.

[0035] (2) The present invention can adapt to different imaging needs and environmental conditions, and has different testing methods in different testing environments.

[0036] (3) The present invention uses a switching switch to switch between transmitting and receiving tests, so that the transmitting function of the RF coil under test can be tested and the receiving function of the RF coil under test can be tested under the same test device, thereby improving the efficiency of the test.

[0037] (4) The present invention can complete the transmission and reception function tests of the tested RF coil in one scan. It has a simple structure, is easy to operate, and has strong applicability. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the circuit structure of the device according to Embodiment 1 of the present invention;

[0039] Figure 2 This is a schematic diagram of the circuit structure for testing the radio frequency coil under test using a magnetic resonance spectrometer in Embodiment 2 of the present invention;

[0040] Figure 3 This is a schematic diagram of the circuit structure used in Embodiment 3 of the present invention to perform the test of the radio frequency coil under test on a workbench using a radio frequency pulse source and a simulated transmit and receive control signal source.

[0041] Figure labels and corresponding component names:

[0042] 10—Magnetic Resonance Analyzer; 102—Worktable; 103—RF Pulse Source; 104—Analog Transmit and Receive Control Signal Source; 105—Signal Adapter Board; 20—Scanning Bed; 21—First Signal Adapter; 22—Second Signal Adapter; 30—Coil Connector; 40—RF Coil Under Test; 50—Small RF Probe; 60—Switch; 70—Attenuator; 80—Signal Measurement Module; 90—Analog MR Signal Generator; 100—Coaxial Cable. Detailed Implementation

[0043] To facilitate understanding and implementation of the present invention by those skilled in the art, the present invention will be further described in detail below with reference to embodiments. The embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0044] Example 1:

[0045] A testing device for a multi-core magnetic resonance radio frequency coil includes a switching switch 60, an attenuator 70, a signal measurement module 80, an analog MR signal generator (analog magnetic resonance signal generator) 90, a coaxial cable 100, a small radio frequency probe 50, and a radio frequency coil under test 40. The radio frequency coil under test 40 is provided with a coil connector 30. The small radio frequency probe 50 is placed within a specified area of ​​the radio frequency coil under test 40 (e.g., at the center of the radio frequency coil under test). The switching switch 60 includes a control input port, a probe connection port, a radio frequency input port, and a radio frequency output port. The small radio frequency probe 50 is connected to the probe connection port of the switching switch 60. The input end of the attenuator 70 is connected to the radio frequency output port of the switching switch 60, and the output end of the attenuator 70 is connected to the input end of the signal measurement module 80. The output end of the analog MR signal generator 90 is connected to the radio frequency input port of the switching switch 60 via the coaxial cable 100.

[0046] The switching switch 60 is used to receive a transmit control signal or a receive control signal, and to switch the small radio frequency probe 50 to transmit or receive state according to the received transmit control signal or receive control signal, corresponding to the switching of the receive state and transmit state of the radio frequency coil 40 under test.

[0047] The small radio frequency probe 50 (smaller than the radio frequency coil 40 under test, so as to be easy to place in the standard area of ​​the radio frequency coil 40 under test) is used to receive the signal generated by the radio frequency coil 40 under test. The small radio frequency probe 50 can be implemented by a small RF coil or a small antenna.

[0048] Attenuator 70 is used to adjust the signal strength to ensure signal stability and reliability.

[0049] The signal measurement module 80 can be an oscilloscope, spectrum analyzer, or other general-purpose measuring instruments and dedicated measuring devices used to monitor and analyze the received signals. The signal measurement module 80 is used to observe both the transmission status and the reception status of the RF coil 40 under test. Before using the signal measurement module 80 for measurement, it is necessary to calibrate the signal measurement module 80 to ensure the accuracy of the acquired signals.

[0050] The simulated MR signal generator 90 is used to simulate the magnetic resonance signal generated by the sample under test after being excited by a radio frequency pulse signal.

[0051] When the transmission function of the tested RF coil 40 is tested, the switch 60 and the signal measurement module 80 receive the transmission control signal. The probe connection port of the switch 60 is connected to the RF output port, and the probe connection port of the switch 60 is disconnected from the RF input port. The small RF probe 50 is in the receiving state, and the transmission control signal is used as the waveform capture trigger signal of the signal measurement module 80.

[0052] When the receiving function of the tested RF coil 40 is tested, the switch 60 and the analog MR signal generator 90 receive the receiving control signal. The probe connection port of the switch 60 is connected to the RF input port, and the probe connection port is disconnected from the RF output port. The small RF probe 50 is in the transmitting state. The receiving control signal is used as the output trigger of the analog MR signal generator 90. The magnetic resonance signal generated by the analog MR signal generator 90 is transmitted to the small RF probe 50, and the tested RF coil 40 receives the magnetic resonance signal transmitted to the small RF probe 50.

[0053] It also includes a data acquisition module, which is used to acquire the magnetic resonance signal received by the tested radio frequency coil 40 when it is in the receiving state, thereby obtaining the received signal and recording and displaying the waveform of the received signal;

[0054] The device of the present invention can be used on the magnetic resonance spectrometer 10 and the worktable 102 respectively.

[0055] It also includes a reference coil. Replacing the RF coil under test 40 with the reference coil allows for relative measurements of the RF coil under test 40 (such as relative transmit efficiency, relative receive efficiency, and relative receive sensitivity).

[0056] Example 2:

[0057] A testing method for multi-core magnetic resonance radio frequency coils, utilizing the testing device for multi-core magnetic resonance radio frequency coils described in Embodiment 1 above, wherein a magnetic resonance spectrometer 10 is used to test the radio frequency coil 40 under test, and further includes a first signal adapter 21, comprising the following steps:

[0058] The device of the present invention is connected to the magnetic resonance imaging (MRI) machine 10 in the following manner: the first signal adapter 21 includes an input port and three output ports. The input port of the first signal adapter 21 is connected to the scanning bed 20 of the MRI machine 10, and the three output ports of the first signal adapter 21 are respectively connected to the control input port of the switching switch 60, the signal measurement module 80, and the analog MR signal generator 90.

[0059] The first signal converter 21 is used to output the transmit control signal to the switch 60 and the signal measurement module 80, and to output the receive control signal to the switch 60 and the analog MR signal generator 90.

[0060] Before measurement, the operating frequency of the RF coil 40 under test is tuned to below the corresponding resonant frequency. The coil resonant frequency is based on the following formula: For example, the resonant frequency of 129Xe at 3T (Tesla, a unit of magnetic flux density) is 35.49MHz, where ω is the resonant frequency of the tested RF coil 40, L is the inductance of the tested RF coil 40, and C...T The tuning capacitor of the RF coil 40 under test is set, and then the RF coil 40 under test is connected to the scanning bed 20 through the coil connector 30 and placed on the scanning bed 20. The small RF probe 50 is placed in the standard area of ​​the RF coil 40 under test.

[0061] In this embodiment, the magnetic resonance spectrometer 10 is used to generate a transmit control signal, a receive control signal, a radio frequency pulse signal, and as a data acquisition module to acquire the magnetic resonance signal received by the radio frequency coil 40 under test when it is in the receiving state, obtain the received signal, and record and display the received signal waveform.

[0062] Step 1: Run a pulse sequence on the magnetic resonance spectrometer 10. When the pulse sequence is in the transmission state, perform a transmission function test on the tested RF coil 40 and determine whether the transmission function of the tested RF coil 40 is normal. The specific steps include:

[0063] Step 1.1: When the pulse sequence is in the transmission state, the magnetic resonance spectrometer 10 generates a radio frequency pulse signal. The first signal converter 21 extracts the transmission control signal from the scanning bed 20 of the magnetic resonance spectrometer 10 and sends it to the switching switch 60 and the signal measurement module 80 respectively. The tested radio frequency coil 40 receives the radio frequency pulse signal. The radio frequency pulse signal excites the tested radio frequency coil 40 to generate a B1+ field (radio frequency field) signal. After the switching switch 60 receives the transmission control signal, the probe connection port of the switching switch 60 is connected to the radio frequency output port. The small radio frequency probe 50 is in the receiving state. After the small radio frequency probe 50 receives the B1+ field signal emitted by the tested radio frequency coil 40, it is input to the signal measurement module 80 through the switching switch 60 and the attenuator 70. The signal measurement module 80 displays and records the waveform of the B1+ field signal received by the small radio frequency probe 50.

[0064] Step 1.2: Observe the B1+ field signal waveform to determine whether the transmission function of the tested RF coil 40 is normal, including: determining whether the amplitude change of the B1+ field signal waveform is within the set range, and whether the timing of the RF pulse signal waveform is consistent with the timing of the B1+ field signal waveform.

[0065] Step 2: When the pulse sequence is in receive mode, perform a receive function test on the tested RF coil 40 and determine whether the receive function of the tested RF coil 40 is normal. This includes the following steps:

[0066] Step 2.1: When the pulse sequence is in the receiving state, the first signal converter 21 extracts the receiving control signal from the scanning bed 20 interface of the magnetic resonance spectrometer 10 and sends it to the switching switch 60 and the analog MR signal generator 90 respectively. After the switching switch 60 receives the receiving control signal, the probe connection port of the switching switch 60 is connected to the radio frequency input port, and the small radio frequency probe 50 is in the transmitting state. After the analog MR signal generator 90 receives the receiving control signal, it simulates and generates the magnetic resonance signal generated by the sample under test after the radio frequency pulse excitation, and transmits it to the small radio frequency probe 50. Then, the radio frequency coil under test 40 receives the magnetic resonance signal radiated by the small radio frequency probe 50 and sends it to the magnetic resonance spectrometer 10 through the coil connector 30. The magnetic resonance spectrometer 10 collects the received signal and records and displays the received signal waveform.

[0067] Step 2.2: Analyze the received signal to determine whether the receiving function of the tested RF coil 40 is normal, including: observing whether there is obvious distortion or irregular fluctuation in the received signal waveform, and checking and analyzing whether the amplitude and noise of the received signal waveform are within the set range.

[0068] Step 3: Change the pulse voltage VT0 of the pulse sequence (i.e., the pulse voltage of the radio frequency pulse signal generated by the magnetic resonance spectrometer 10), and then run the pulse sequence. When the pulse sequence is running in the transmission state, measure the transmission efficiency of the radio frequency coil 40 under test. Replace the radio frequency coil 40 under test with the reference coil and measure the relative transmission efficiency of the radio frequency coil 40 under test. Specifically, this includes the following steps:

[0069] Step 3.1: When the pulse sequence is running in the transmission state, repeat step 1.1. The signal measurement module 80 receives and displays the B1+ field signal waveform, obtains the amplitude V1 of the B1+ field signal waveform based on the B1+ field signal waveform, and calculates the ratio V1 / VT0. V1 / VT0 is used to evaluate the transmission efficiency of the tested RF coil 40.

[0070] Step 3.2: Replace the RF coil under test 40 with the reference coil, and then repeat step 3.1 to obtain the transmission efficiency of the reference coil. Then calculate the ratio of the transmission efficiency of the RF coil under test 40 to that of the reference coil under the same test conditions to evaluate the relative transmission efficiency of the RF coil under test 40 under specific test conditions.

[0071] Step 4: When the pulse sequence is in receiving mode, change the amplitude VR0 of the magnetic resonance signal output by the analog MR signal generator 90, and measure the receiving efficiency and receiving sensitivity of the tested RF coil 40. Replace the tested RF coil 40 with the reference coil and measure the relative receiving efficiency and relative receiving sensitivity of the tested RF coil 40. Specifically, this includes the following steps:

[0072] Step 4.1: When the pulse sequence is running in the receiving state, change the amplitude VR0 of the magnetic resonance signal output by the analog MR signal generator 90, repeat step 2.1, the magnetic resonance instrument 10 acquires and displays the received signal waveform, obtains the amplitude VR1 of the received signal waveform, and calculates the ratio VR1 / VR0. VR1 / VR0 is used to evaluate the receiving efficiency of the tested RF coil 40.

[0073] Step 4.2: Reduce the amplitude VR0 of the magnetic resonance signal output by the analog MR signal generator 90, and obtain the output amplitude VR0min of the analog MR signal generator 90 corresponding to the smallest received signal that the magnetic resonance instrument 10 can resolve. VR0min is used to evaluate the receiving sensitivity of the tested radio frequency coil 40 under specific test conditions.

[0074] Step 4.3: Replace the RF coil under test 40 with the reference coil, and then repeat steps 4.1 and 4.2 to obtain the receiving efficiency of the reference coil. Then calculate the ratio of the receiving efficiency of the RF coil under test 40 to that of the reference coil under the same test conditions, as well as the ratio of VR0min of the RF coil under test 40 to that of the reference coil under the same test conditions. These are used to evaluate the relative receiving efficiency and relative receiving sensitivity of the RF coil under test 40 under the same test conditions.

[0075] When using the magnetic resonance spectrometer 10, the transmission and reception functions of the radio frequency coil under test 40 can be tested simultaneously during a single pulse sequence scan on the magnetic resonance spectrometer 10.

[0076] Example 3:

[0077] A testing method for multi-core magnetic resonance radio frequency coils utilizes the testing apparatus for multi-core magnetic resonance radio frequency coils described in Embodiment 1 above. In this embodiment, a radio frequency pulse source 103 and an analog transmit and receive control signal source 104 are used to complete the testing of the radio frequency coil 40 under test on a workbench 102. The method also includes a signal adapter board 105 and a second signal adapter 22, and includes the following steps:

[0078] The device of the present invention is connected to the radio frequency pulse source 103 and the analog transmit and receive control signal source 104 in the following manner:

[0079] The signal adapter board 105 includes two input ports and two output ports, namely a first input port, a second input port, a first output port, and a second bidirectional port. The second signal adapter 22 includes one input port and five output ports, namely a first output port, a second output port, a third output port, a fourth output port, and a fifth output port. The first input port of the signal adapter board 105 is connected to the output port of the radio frequency pulse source 103, and the second input port of the signal adapter board 105 is connected to the output port of the analog transmit and receive control signal source 104. The output port is connected to the first input port of the second signal adapter 22, the second bidirectional port of the signal adapter board 105 is connected to the coil connector 30, the first output port of the second signal adapter 22 is connected to the control input port of the switch 60, the second output port of the second signal adapter 22 is connected to the signal measurement module 80, the third output port of the second signal adapter 22 is connected to the analog MR signal generator 90, the fourth output port of the second signal adapter 22 is connected to the radio frequency pulse source 103, and the fifth output port of the second signal adapter 22 is connected to the independent signal input channel of the signal measurement module 80.

[0080] In this embodiment, the signal measurement module 80 is used to display and record the B1+ field signal waveform and the transmit control signal waveform received by the small radio frequency probe 50, and also serves as an acquisition module to acquire the magnetic resonance signal received by the radio frequency coil 40 under test when it is in the receiving state, obtain the received signal, and record and display the received signal waveform.

[0081] The radio frequency pulse source 103 is used to simulate and generate radio frequency pulse signals and provide them to the radio frequency coil 40 under test for transmission function testing.

[0082] The simulated transmit and receive control signal source 104 is used to simulate transmit control signals or receive control signals.

[0083] The first input port of the second signal adapter 22 is used to acquire the analog transmit control signal or receive control signal, as well as the received signal from the RF coil under test 40. The transmit control signal or receive control signal is split into five paths by a splitter in the second signal adapter 22. One path is input to the switch 60 through the first output port to switch the transmit or receive state of the small RF probe 50; another path is input to the signal measurement module 80 through the second output port as a waveform capture trigger signal; another path is input to the analog MR signal generator 90 through the third output port for output triggering; and the third path is input to the RF pulse source 103 through the fourth output port as a trigger signal. Additionally, the received signal from the RF coil under test 40 is input to the independent signal input channel of the signal measurement module 80 through the fifth output port for acquisition and analysis.

[0084] Before measurement, the operating frequency of the RF coil 40 under test should be adjusted to below the corresponding resonant frequency, and the small RF probe 50 should be placed in the standard area of ​​the RF coil 40 under test.

[0085] Step 1: Simulate the transmission and reception control signal source 104 to generate a transmission control signal. After receiving the transmission control signal, the RF pulse source 103 generates an RF pulse signal to test the transmission function of the RF coil 40 under test and determine whether the transmission function of the RF coil 40 under test is normal. This includes the following steps:

[0086] Step 1.1: The simulated transmit and receive control signal source 104 simulates and generates a transmit control signal. The transmit control signal is sent to the switching switch 60, the signal measurement module 80, and the RF pulse source 103 through the second signal adapter 22. After receiving the transmit control signal, the RF pulse source 103 generates an RF pulse signal. The tested RF coil 40 receives the RF pulse signal, which excites the tested RF coil 40 to generate a B1+ field signal. After receiving the transmit control signal, the switching switch 60 connects the probe connection port and the RF output port, and the small RF probe 50 is in the receiving state. After receiving the B1+ field signal emitted by the tested RF coil 40, the small RF probe 50 inputs it into the signal measurement module 80. The signal measurement module 80 displays and records the waveform of the B1+ field signal received by the small RF probe 50.

[0087] Step 1.2: Observe the B1+ field signal waveform to determine whether the transmission function of the tested RF coil 40 is normal, including: determining whether the amplitude change of the B1+ field signal waveform is within the set range, and whether the timing of the RF pulse signal waveform is consistent with the timing of the B1+ field signal waveform.

[0088] Step 2: Simulate the transmission and reception control signal source 104 to generate a simulated reception control signal to test the reception function of the tested RF coil 40 and determine whether the reception function of the tested RF coil 40 is normal. This includes the following steps:

[0089] Step 2.1: The simulated transmit and receive control signal source 104 simulates and generates a receive control signal. The receive control signal is sent to the switching switch 60 and the simulated MR signal generator 90 through the second signal adapter 22. After receiving the receive control signal, the switching switch 60 connects the probe connection port and the RF input port, and the small RF probe 50 is in the transmit state. After receiving the receive control signal, the simulated MR signal generator 90 simulates and generates the magnetic resonance signal generated by the sample under test after RF pulse excitation, and transmits it to the small RF probe 50. Then, the magnetic resonance signal radiated by the small RF probe 50 is received by the RF coil under test 40 and transmitted to the signal adapter board 105. Then, it is sent to the signal measurement module 80 through the second signal adapter 22. The signal measurement module 80 collects the received signal and records and displays the received signal waveform.

[0090] Step 2.2: Analyze the received signal to determine whether the receiving function of the tested RF coil 40 is normal: observe whether there is obvious distortion or irregular fluctuation in the received signal waveform, and check whether the amplitude and noise of the received signal waveform are within the set range.

[0091] Step 3: Change the pulse voltage VT0 of the RF pulse output by the RF pulse source 103, measure the transmission efficiency of the RF coil under test 40, replace the RF coil under test 40 with the reference coil, and measure the relative transmission efficiency of the RF coil under test 40. Specifically, this includes the following steps:

[0092] Step 3.1: Change the pulse voltage VT0 of the RF pulse output by the RF pulse source 103, repeat step 1.1, the signal measurement module 80 receives and displays the B1+ field signal waveform, obtains the amplitude V1 of the B1+ field signal waveform according to the B1+ field signal waveform, calculates the ratio V1 / VT0, and V1 / VT0 is used to evaluate the transmission efficiency of the RF coil 40 under test.

[0093] Step 3.2: Replace the RF coil under test 40 with the reference coil, and then repeat step 3.1 to obtain the transmission efficiency of the reference coil. Then calculate the ratio of the transmission efficiency of the RF coil under test 40 to that of the reference coil under the same test conditions to evaluate the relative transmission efficiency of the RF coil under test 40 under specific test conditions.

[0094] Step 4: Change the amplitude VR0 of the magnetic resonance signal output by the analog MR signal generator 90, and measure the receiving efficiency and receiving sensitivity of the tested RF coil 40. Replace the tested RF coil 40 with the reference coil and measure the relative receiving efficiency and relative receiving sensitivity of the tested RF coil 40. This specifically includes the following steps:

[0095] Step 4.1: Change the amplitude VR0 of the magnetic resonance signal output by the analog MR signal generator 90, repeat step 2.1, the signal measurement module 80 collects and displays the received signal waveform, obtains the amplitude VR1 of the received signal waveform, and calculates the ratio VR1 / VR0. VR1 / VR0 is used to evaluate the receiving efficiency of the tested RF coil 40.

[0096] Step 4.2: Reduce the amplitude VR0 of the magnetic resonance signal output by the analog MR signal generator 90, and obtain the output amplitude VR0min of the analog MR signal generator 90 corresponding to the smallest received signal that the signal measurement module 80 can distinguish. VR0min is used to evaluate the receiving sensitivity of the tested RF coil 40 under specific test conditions.

[0097] Step 4.3: Replace the RF coil under test 40 with the reference coil, and then repeat steps 4.1 and 4.2 to obtain the receiving efficiency of the reference coil. Then calculate the ratio of the receiving efficiency of the RF coil under test 40 to that of the reference coil under the same test conditions, as well as the ratio of VR0min of the RF coil under test 40 to that of the reference coil under the same test conditions. These values ​​are used to evaluate the relative receiving efficiency and relative receiving sensitivity of the RF coil under test 40 under the same test conditions.

[0098] The transmit and receive functions of the tested RF coil 40 can be tested simultaneously in a single simulated scan on the workbench 102.

[0099] Furthermore, in Embodiments 1 and 2 above, the receiving efficiency is defined as the ratio of the signal amplitude received by the tested RF coil 40 to the output amplitude of the analog MR signal source; the receiving sensitivity is defined as the output amplitude of the analog MR signal source corresponding to the smallest received signal that the tested RF coil 40 can resolve.

[0100] It should be noted that the embodiments described in this invention are merely illustrative of the spirit of the invention. Those skilled in the art to which this invention pertains can make various modifications or additions to the described embodiments or use similar methods to substitute them, without departing from the spirit of the invention or exceeding the scope defined by the appended claims.

Claims

1. A testing apparatus for multi-nuclear magnetic resonance radio frequency coils, comprising a radio frequency coil under test (40), characterized in that, It also includes a switching switch (60), an attenuator (70), a signal measurement module (80), an analog MR signal generator (90), a coaxial cable (100), a small RF probe (50), and a reference coil. The RF coil under test (40) is provided with a coil connector (30). The small RF probe (50) is placed in the standard area of ​​the RF coil under test (40). The switching switch (60) includes a control input port, a probe connection port, an RF input port, and an RF output port. The small RF probe (50) is connected to the probe connection port of the switching switch (60). The input end of the attenuator (70) is connected to the RF output port of the switching switch (60). The output end of the attenuator (70) is connected to the input end of the signal measurement module (80). The output end of the analog MR signal generator (90) is connected to the RF input port of the switching switch (60) through the coaxial cable (100). It also includes a data acquisition module, which acquires the magnetic resonance signal received by the radio frequency coil (40) under test when it is in the receiving state, obtains the received signal, and records and displays the waveform of the received signal; Replace the reference coil with the RF coil under test (40) to perform relative measurement of the RF coil under test (40); When the test of the radio frequency coil (40) under test is completed using a magnetic resonance spectrometer (10), a first signal adapter (21) is also included. The input port of the first signal adapter (21) is connected to the scanning bed (20) of the magnetic resonance spectrometer (10), and the three output ports of the first signal adapter (21) are respectively connected to the control input port of the switching switch (60), the signal measurement module (80), and the analog MR signal generator (90). When the test of the RF coil (40) under test is performed on the workbench (102) using an RF pulse source (103) and an analog transmit and receive control signal source (104), a signal adapter board (105) and a second signal adapter (22) are also included. The first input port of the signal adapter board (105) is connected to the output port of the RF pulse source (103), the second input port of the signal adapter board (105) is connected to the output port of the analog transmit and receive control signal source (104), and the first output port of the signal adapter board (105) is connected to the first input port of the second signal adapter (22). The second bidirectional port of the adapter board (105) is connected to the coil connector (30), the first output port of the second signal adapter (22) is connected to the control input port of the switch (60), the second output port of the second signal adapter (22) is connected to the signal measurement module (80), the third output port of the second signal adapter (22) is connected to the analog MR signal generator (90), the fourth output port of the second signal adapter (22) is connected to the radio frequency pulse source (103), and the fifth output port of the second signal adapter (22) is connected to the independent signal input channel of the signal measurement module (80).

2. A testing method for multi-core magnetic resonance radio frequency coils, utilizing the testing apparatus for multi-core magnetic resonance radio frequency coils as described in claim 1, characterized in that, Includes the following steps: Step 1: Obtain the transmission control signal and radio frequency pulse signal, perform the transmission function test of the radio frequency coil (40) under test, and determine whether the transmission function of the radio frequency coil (40) under test is normal. Step 2: Obtain the receiving control signal, perform the receiving function test of the RF coil (40) under test, and determine whether the receiving function of the RF coil (40) under test is normal. Step 3: Change the pulse voltage VT0 of the radio frequency pulse signal, measure the transmission efficiency of the radio frequency coil (40) under test, replace the radio frequency coil (40) under test with the reference coil, and measure the relative transmission efficiency of the radio frequency coil (40) under test. Step 4: Change the amplitude VR0 of the magnetic resonance signal output by the analog MR signal generator (90), measure the receiving efficiency and receiving sensitivity of the tested RF coil (40), replace the tested RF coil (40) with the reference coil, and measure the relative receiving efficiency and relative receiving sensitivity of the tested RF coil (40).

3. The testing method for multi-nuclear magnetic resonance radio frequency coils according to claim 2, characterized in that, Step 1 specifically includes the following steps: Step 1.1: Input the transmission control signal to the switch (60) and the signal measurement module (80), and input the radio frequency pulse signal to the radio frequency coil under test (40). After the radio frequency coil under test (40) receives the radio frequency pulse signal, the radio frequency pulse signal excites the radio frequency coil under test (40) to generate a B1+ field signal. After the switch (60) receives the transmission control signal, the probe connection port of the switch (60) and the radio frequency output port are connected, and the small radio frequency probe (50) is in the receiving state. After the small radio frequency probe (50) receives the B1+ field signal emitted by the radio frequency coil under test (40), it is input to the signal measurement module (80). The signal measurement module (80) displays and records the B1+ field signal waveform received by the small radio frequency probe (50). Step 1.2: Observe the B1+ field signal waveform to determine whether the transmission function of the tested RF coil (40) is normal, including: determining whether the amplitude change of the B1+ field signal waveform is within the set range, and whether the timing of the RF pulse signal waveform is consistent with the timing of the B1+ field signal waveform.

4. The testing method for multi-nuclear magnetic resonance radio frequency coils according to claim 3, characterized in that, Step 2 specifically includes the following steps: Step 2.1: Input the receiving control signal to the switch (60) and the analog MR signal generator (90). After the switch (60) receives the receiving control signal, the probe connection port of the switch (60) is connected to the radio frequency input port. After the analog MR signal generator (90) receives the receiving control signal, it simulates and generates a magnetic resonance signal and transmits it to the small radio frequency probe (50). Then, the magnetic resonance signal radiated by the small radio frequency probe (50) is received by the radio frequency coil under test (40) and then the received signal is acquired by the acquisition module. The received signal waveform is recorded and displayed. Step 2.2: Analyze the received signal to determine whether the receiving function of the tested RF coil (40) is normal: observe whether there is obvious distortion or irregular fluctuation in the received signal waveform, and check whether the amplitude and noise of the received signal waveform are within the set range.

5. The testing method for a multi-nuclear magnetic resonance radio frequency coil according to claim 4, characterized in that, Step 3, measuring the emission efficiency of the RF coil (40) under test, specifically includes the following steps: Step 3.1: Change the pulse voltage VT0 of the radio frequency pulse signal, repeat step 1.1, receive and display the B1+ field signal waveform through the signal measurement module (80), obtain the amplitude V1 of the B1+ field signal waveform according to the B1+ field signal waveform, and calculate the ratio V1 / VT0. Step 3.2: Replace the RF coil under test (40) with the reference coil, and then repeat step 3.1 to obtain the transmission efficiency of the reference coil. Then calculate the ratio of the transmission efficiency of the RF coil under test (40) to that of the reference coil under the same test conditions.

6. The testing method for a multi-nuclear magnetic resonance radio frequency coil according to claim 5, characterized in that, Step 4, measuring the receiving sensitivity of the RF coil (40) under test, specifically includes the following steps: Step 4.1: Change the amplitude VR0 of the magnetic resonance signal output by the analog MR signal generator (90), repeat step 2.1, the acquisition module acquires and displays the received signal waveform, obtains the amplitude VR1 of the received signal waveform, and calculates the ratio VR1 / VR0; Step 4.2: Reduce the amplitude VR0 of the magnetic resonance signal output by the analog MR signal generator (90) and obtain the output amplitude VR0min of the analog MR signal generator (90) corresponding to the smallest received signal that the acquisition module can distinguish; Step 4.3: Replace the RF coil under test (40) with the reference coil, and then repeat steps 4.1 and 4.2 to obtain the receiving efficiency of the reference coil. Then calculate the ratio of the receiving efficiency of the RF coil under test (40) and the reference coil under the same test conditions, as well as the ratio of VR0min of the RF coil under test (40) to VR0min of the reference coil.

7. The testing method for a multi-nuclear magnetic resonance radio frequency coil according to claim 6, characterized in that, When the magnetic resonance spectrometer (10) is used to generate radio frequency pulse signals, transmit control signals, and receive control signals, a first signal converter (21) is also included. The first signal converter (21) includes an input port and three output ports. The input port of the first signal converter (21) is connected to the scanning bed (20) of the magnetic resonance spectrometer (10). The three output ports of the first signal converter (21) are respectively connected to the control input port of the switching switch (60), the signal measurement module (80), and the analog MR signal generator (90). The radio frequency coil (40) under test is placed on the scanning bed (20) of the magnetic resonance spectrometer (10). The radio frequency coil (40) under test is connected to the scanning bed (20) of the magnetic resonance spectrometer (10). The radio frequency pulse signal, the transmit control signal, and the receive control signal are generated in the following manner: a pulse sequence is run on the magnetic resonance spectrometer (10). When the pulse sequence is running in the transmit state, the magnetic resonance spectrometer (10) generates a radio frequency pulse signal, and the scanning bed (20) of the magnetic resonance spectrometer (10) generates a transmit control signal; when the pulse sequence is running in the receive state, the scanning bed (20) of the magnetic resonance spectrometer (10) generates a receive control signal. The acquisition module is a magnetic resonance spectrometer (10). The radio frequency coil (40) under test receives the magnetic resonance signal radiated by the small radio frequency probe (50) and sends it to the magnetic resonance spectrometer (10) through the coil connector (30). The magnetic resonance spectrometer (10) acquires the received signal and records and displays the waveform of the received signal.

8. The testing method for a multi-nuclear magnetic resonance radio frequency coil according to claim 6, characterized in that, When a simulated transmit and receive control signal source (104) is used to generate transmit control signals and receive control signals, and a radio frequency pulse signal is generated using a radio frequency pulse source (103), a signal adapter board (105) and a second signal adapter (22) are also included. The signal adapter board (105) includes a first input port, a second input port, a first output port, and a second bidirectional port. The second signal adapter (22) includes a first output port, a second output port, a third output port, a fourth output port, and a fifth output port. The first input port of the signal adapter board (105) is connected to the output port of the radio frequency pulse source (103), and the second input port of the signal adapter board (105) is connected to the output port of the simulated transmit and receive control signal source (104). The first output port of the signal adapter board (105) is connected to the first input port of the second signal adapter (22), the second bidirectional port of the signal adapter board (105) is connected to the coil connector (30), the first output port of the second signal adapter (22) is connected to the control input port of the switch (60), the second output port of the second signal adapter (22) is connected to the signal measurement module (80), the third output port of the second signal adapter (22) is connected to the analog MR signal generator (90), the fourth output port of the second signal adapter (22) is connected to the radio frequency pulse source (103), and the fifth output port of the second signal adapter (22) is connected to the independent signal input channel of the signal measurement module (80). The radio frequency pulse signal, the transmit control signal, and the receive control signal are generated in the following way: the simulated transmit and receive control signal source (104) simulates the transmit control signal and sends the transmit control signal to the switching switch (60), the signal measurement module (80), and the radio frequency pulse source (103). After receiving the transmit control signal, the radio frequency pulse source (103) generates the radio frequency pulse signal. The simulated transmit and receive control signal source (104) simulates the generation of receive control signals; The acquisition module is a signal measurement module (80). The radio frequency coil (40) under test receives the magnetic resonance signal radiated by the small radio frequency probe (50) and then transmits it to the signal adapter board (105). Then, it is sent to the signal measurement module (80) through the second signal adapter (22). The signal measurement module (80) acquires the received signal and records and displays the waveform of the received signal.

Images