Phase calibration checking method, device and magnetic resonance imaging system

Abstract

This invention discloses a phase calibration check method, apparatus, and magnetic resonance imaging (MRI) system. The method includes: multiplying N digital magnetic resonance echo signals from an analog receiver of the MRI system by an identity matrix; calculating the measured phase of each of the N coil units participating in the current MRI scan based on each digital magnetic resonance echo signal in the calculation results; determining the spatial distribution of the N coil units according to the current MRI scan direction; determining the designed phase of each of the N coil units based on the spatial distribution of the N coil units; comparing the measured phase with the designed phase of each of the N coil units; and determining whether each coil unit passes the phase calibration check based on the comparison results. This invention improves the accuracy of the phase calibration check.

Description

Technical Field

[0001] This invention relates to the field of MRI (Magnetic Resonance Imaging) technology, and in particular to phase calibration examination methods, devices and MRI systems. Background Technology

[0002] An MRI system typically includes a receiving coil, a scan bed socket, a receiving coil channel selector, an analog receiver, a mode matrix processor, a digital receiver, and an image data processor. Specifically: the receiving coil receives N magnetic resonance echo signals from N coil units; the initial phase of the N magnetic resonance echo signals entering the N coil units is the spatial phase of the magnetic resonance echo signal. The N magnetic resonance echo signals travel through the receiving coil to the scan bed socket, and then through the system cable to the receiving coil channel selector. The receiving coil channel selector receives the magnetic resonance echo signals and transmits them to the analog receiver after channel mapping. The analog receiver performs a first sampling of the N magnetic resonance echo signals and performs analog-to-digital conversion; the first sampling result after analog-to-digital conversion is transmitted to the mode matrix processor. The mode matrix processor transmits the N digital magnetic resonance echo signals in parallel to the digital receiver. The digital receiver performs a second sampling of the received digital mode signals to obtain the raw data for image processing. The image data processor performs Fourier transforms and post-processing to form an MRI image.

[0003] The existing mode matrix processor's processing procedure involves complex number operations. It multiplies the N digital magnetic resonance echo signals output from the analog receiver by a predetermined mode matrix, outputting at least one mode signal. For example, the first mode signal (CP mode signal), the second mode signal (LR mode signal), and the third mode signal (ACP mode signal) represent the first mode and two higher-order modes output by the mode matrix processor, respectively. Typically, the mode matrix processor only outputs the first mode signal (CP mode signal). The mode matrix is ​​a complex matrix. In its implementation, the multiplication of the N digital magnetic resonance echo signals by the predetermined mode matrix is ​​achieved through a power divider performing subtraction, a synthesizer performing addition, and a phase shifter performing complex number operations.

[0004] Since the phase delays of the N coil units from receiving the magnetic resonance echo signal to completing the analog receiver sampling are different, it is necessary to calibrate these different phase differences (delays). The magnetic resonance echo signal passes through the receiving coil and the magnetic resonance imaging system, so the phase difference (delay) can be divided into: 1) coil phase difference (external delay), which is the phase difference generated by the magnetic resonance echo signal passing through the receiving coil, and 2) system phase difference (internal delay), which is the phase difference generated by the magnetic resonance echo signal passing through the magnetic resonance imaging system.

[0005] Therefore, accurate calibration of the coil phase and system phase is a key factor in ensuring the good performance of the mode matrix processor. Currently, coil phase calibration is completed before the coil leaves the factory. Figure 1 A flowchart of the existing phase calibration check method is provided, and its specific steps are as follows:

[0006] Step 101: The mode matrix processor multiplies the N digital magnetic resonance echo signals from the analog receiver by the set MoMa matrix to obtain the CP mode signal.

[0007] Step 102: Calculate the combined SNR (signal-to-noise ratio) of the N coil units participating in this magnetic resonance imaging scan based on the CP mode signal, and compare the calculated combined SNR with the pre-set design combined SNR of the coil units using a combined coil QA (Quality Assurance) test tool.

[0008] Step 103: Based on the comparison results, determine whether the calculated combined SNR is qualified. If yes, proceed to step 104; otherwise, proceed to step 105.

[0009] Step 104: Once N coil units are confirmed to be fault-free, this process ends.

[0010] Step 105: Use non-combined coil QA to measure the SNR of each coil unit in N coil units, and compare the measured SNR of each coil unit with the designed SNR of the corresponding coil unit.

[0011] Step 106: For each coil unit, determine whether the coil unit is normal based on the comparison result. If it is, proceed to step 108; otherwise, proceed to step 107.

[0012] Step 107: Replace the malfunctioning coil unit. This process is now complete.

[0013] Step 108: Use relevant testing tools such as TU and QA to check the RF receiving system of the coil unit.

[0014] Step 109: Based on the inspection results, determine whether the RF receiving system of the coil unit is normal. If yes, proceed to step 111; otherwise, proceed to step 110.

[0015] Step 110: Replace the RF receiving system of this coil unit. This process is now complete.

[0016] Step 111: Multiply the latest N digital magnetic resonance echo signals from the analog receiver by the set MoMa matrix to obtain the latest CP mode signal.

[0017] Step 112: Calculate the combined SNR of the N coil units according to the latest CP mode signal, and use the combined coil QA to compare the calculated combined SNR with the designed combined SNR of the preset coil units.

[0018] Step 113: According to the comparison result, determine whether the calculated combined SNR is qualified. If so, execute Step 114; otherwise, execute Step 115.

[0019] Step 114: Determine that the N coil units are free of faults, and this process ends.

[0020] Step 115: It is considered that the phase calibration component may be faulty.

[0021] In the worst case, if it is determined through the above process that all other inspections show qualified, but only the combined SNR of the coil units is unqualified, it is difficult to determine the root cause, and it is also impossible to determine whether the phase calibration accuracy is qualified, because the above process can only check the amplitude of the signals in each RF receiving channel when inspecting the RF receiving system of the coil unit, so as to only check whether the signals are connected. Summary of the Invention

[0022] In view of this, on the one hand, an embodiment of the present invention proposes a phase calibration inspection method, and on the other hand, a phase calibration inspection device and an MRI system are proposed to improve the accuracy of phase calibration inspection.

[0023] A phase calibration inspection method includes:

[0024] Multiply N digital magnetic resonance echo signals from the analog receiver of the magnetic resonance imaging system by the identity matrix, where N is a positive integer;

[0025] According to each digital magnetic resonance echo signal in the calculation result, calculate the measured phase of each coil unit among the N coil units participating in this magnetic resonance scan respectively;

[0026] According to the direction of this magnetic resonance scan, determine the spatial distribution of the N coil units matching the direction of this magnetic resonance scan, and according to the spatial distribution of the N coil units, determine the designed phase of each coil unit among the N coil units;

[0027] Compare the measured phase and the designed phase of each coil unit among the N coil units respectively, and determine whether each coil unit passes the phase calibration inspection according to the comparison result.

[0028] After determining the designed phase of each coil unit among the N coil units and before comparing the measured phase and the designed phase of each coil unit among the N coil units respectively, it further includes:

[0029] Arbitrarily select one coil unit from the N coil units, and calculate the difference between the design phase and the measurement phase of the selected coil unit; add the difference to the measurement phase of each of the N coil units to obtain the regularized measurement phase of each coil unit;

[0030] The step of comparing the measured phase with the designed phase of each of the N coil units includes:

[0031] Calculate the difference between the regularized measured phase and the design phase for each of the N coil units;

[0032] The step of determining whether each coil unit passes the phase calibration check based on the comparison results includes:

[0033] For each of the N coil units, if the difference between the measured phase and the designed phase of the coil unit is within a preset range, then the coil unit is determined to have passed the phase calibration check; otherwise, the coil unit is determined to have failed the phase calibration check.

[0034] After determining whether each coil unit has passed the phase calibration check based on the comparison results, the process further includes:

[0035] If any coil unit fails the phase calibration check, the user will be notified to recalibrate the coil phase or / and the system phase.

[0036] A phase calibration inspection device, comprising:

[0037] The matrix calculation module is used to multiply N digital magnetic resonance echo signals from the analog receiver of the magnetic resonance imaging system by an identity matrix, where N is a positive integer;

[0038] The measurement phase calculation module is used to calculate the measurement phase of each of the N coil units participating in this magnetic resonance scan based on each digital magnetic resonance echo signal in the calculation results of the matrix calculation module.

[0039] The design phase determination module is used to determine the spatial distribution of the N coil units that match the current scanning direction, and to determine the design phase of each of the N coil units based on the spatial distribution of the N coil units.

[0040] The inspection module is used to compare the measured phase with the designed phase of each of the N coil units, and determine whether each coil unit passes the phase calibration inspection based on the comparison results.

[0041] Before comparing the measured phase with the designed phase of each of the N coil units, the inspection module is further used for:

[0042] Arbitrarily select one coil unit from the N coil units, and calculate the difference between the design phase and the measurement phase of the selected coil unit; add the difference to the measurement phase of each of the N coil units to obtain the regularized measurement phase of each coil unit;

[0043] The inspection module compares the measured phase with the designed phase of each of the N coil units, including:

[0044] Calculate the difference between the regularized measured phase and the design phase for each of the N coil units;

[0045] The inspection module determines whether each coil unit passes the phase calibration check based on the comparison results, including:

[0046] For each of the N coil units, if the difference between the measured phase and the designed phase of the coil unit is within a preset range, then the coil unit is determined to have passed the phase calibration check; otherwise, the coil unit is determined to have failed the phase calibration check.

[0047] After determining whether each coil unit has passed the phase calibration check based on the comparison results, the inspection module is further used for:

[0048] If any coil unit fails the phase calibration check, the user will be notified to recalibrate the coil phase or / and the system phase.

[0049] The device is located in the mode matrix processor of the magnetic resonance imaging system.

[0050] A magnetic resonance imaging system includes any of the devices described above.

[0051] In the above embodiments, after receiving N digital magnetic resonance echo signals from the analog receiver, the matrix operation is performed by multiplying the identity matrix instead of the mode matrix containing complex elements. The result is the original N digital magnetic resonance echo signals, thus obtaining the measured phase of each of the N coil units. The measured phase of each coil unit is then compared with the design phase. Based on the comparison results, it is determined whether each coil unit has passed the phase calibration check. Since the phase of the coil unit can reflect whether there are problems with the RF connection and RF cable, the above embodiments can quickly check whether there are problems with the RF connection and RF cable of the magnetic resonance imaging system, improve the accuracy of the phase calibration check, quickly locate faults, and have strong robustness. Attached Figure Description

[0052] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which will make the above and other features and advantages of the present invention more apparent to those skilled in the art. In the drawings:

[0053] Figure 1 Here is a flowchart of the existing phase calibration inspection method;

[0054] Figure 2 This is a flowchart of the phase calibration and inspection method provided in the first embodiment of the present invention;

[0055] Figure 3 This is a flowchart of the phase calibration and inspection method provided in the second embodiment of the present invention;

[0056] Figure 4 This is a schematic diagram of the spatial distribution of the six coil units involved in this magnetic resonance imaging scan in an application example of the present invention;

[0057] Figure 5 The amplitude and phase diagrams of the magnetic resonance echo images acquired by the six coil units involved in this magnetic resonance imaging scan are shown in an application example of the present invention.

[0058] Figure 6 This is a schematic diagram of the phase calibration and inspection device provided in an embodiment of the present invention.

[0059] The reference numerals in the attached figures are as follows:

[0060]

[0061] Detailed Implementation

[0062] To make the objectives, technical solutions, and advantages of the present invention clearer, the following embodiments are provided to further illustrate the present invention in detail.

[0063] Figure 2 The flowchart of the phase calibration inspection method provided in the first embodiment of the present invention is as follows:

[0064] Step 201: Multiply the N digital magnetic resonance echo signals from the analog receiver of the magnetic resonance imaging system by the identity matrix, where N is a positive integer.

[0065] An identity matrix is ​​a matrix in which all elements on the diagonal are 1 and all other elements are 0.

[0066] Step 202: Based on each digital magnetic resonance echo signal in the calculation results, calculate the measured phase of each of the N coil units participating in this magnetic resonance scan.

[0067] Each digital magnetic resonance echo signal corresponds to a coil unit. Each digital magnetic resonance echo signal is a complex number format data with real and imaginary parts. Therefore, the phase of the corresponding coil unit can be calculated based on the values ​​of its real and imaginary parts.

[0068] Step 203: Based on the direction of this magnetic resonance scan, determine the spatial distribution of N coil units, and based on the spatial distribution of N coil units, determine the design phase of each coil unit in the N coil units.

[0069] Step 204: Compare the measured phase with the designed phase of each of the N coil units, and determine whether each coil unit passes the phase calibration check based on the comparison results.

[0070] In the above embodiments, the execution entity for each step is the mode matrix processor of the magnetic resonance imaging system. Because existing mode matrix processors, upon receiving N digital magnetic resonance echo signals from an analog receiver, must first perform mode matrix operations involving complex number operations—that is, multiplying the N digital magnetic resonance echo signals by a mode matrix containing complex elements—they cannot determine the phase of each of the N coil units based on the calculation result. In the above embodiments, after receiving the N digital magnetic resonance echo signals from the analog receiver, the mode matrix processor, during matrix operations, does not multiply by a mode matrix containing complex elements, but by an identity matrix. Therefore, the calculation result is the original N digital magnetic resonance echo signals, enabling the determination of the measured phase of each of the N coil units. The measured phase of each coil unit is then compared with the designed phase. Based on the comparison result, it is determined whether each coil unit has passed the phase calibration check. Since the phase of the coil unit can reflect whether there are problems with the RF connection and RF cable, the above embodiments can quickly detect problems with the RF connection and RF cable of the magnetic resonance imaging system, improving the accuracy of the phase calibration check, enabling rapid fault location, and exhibiting strong robustness.

[0071] In one optional embodiment, after step 203 and before step 204, the method further includes: arbitrarily selecting one coil unit from the N coil units, calculating the difference between the design phase and the measurement phase of the selected coil unit; and adding the difference to the measurement phase of each of the N coil units to obtain the regularized measurement phase of each coil unit.

[0072] Furthermore, in step 204, the measured phase of each of the N coil units is compared with the designed phase, including: calculating the difference between the regularized measured phase and the designed phase of each of the N coil units.

[0073] Furthermore, in step 204, determining whether each coil unit passes the phase calibration check based on the comparison results includes: for each coil unit among the N coil units, if the difference between the measured phase and the designed phase of the coil unit is within a preset range, then the coil unit is determined to have passed the phase calibration check; otherwise, the coil unit is determined to have failed the phase calibration check.

[0074] In the above embodiments, by aligning the measured phase of one coil unit with the design phase, and then adjusting the measured phases of other coil units in the same way according to the difference between the measured phase and the design phase of that coil unit, and then comparing the measured phase with the design phase of each coil unit, the accuracy of phase calibration check is improved.

[0075] In one optional embodiment, after determining whether each coil unit has passed the phase calibration check based on the comparison results in step 204, the method further includes: if any coil unit fails the phase calibration check, the user is notified to re-perform coil phase calibration or / and system phase calibration.

[0076] Figure 3 The flowchart of the phase calibration inspection method provided in the second embodiment of the present invention is as follows:

[0077] Step 301: The mode matrix processor multiplies the N digital magnetic resonance echo signals from the analog receiver of the magnetic resonance imaging system by the identity matrix, where N is a positive integer.

[0078] Existing mode matrix processors, upon receiving N digital magnetic resonance echo signals from an analog receiver, must first perform mode matrix operations involving complex number arithmetic. This involves multiplying the N digital magnetic resonance echo signals by a mode matrix containing complex elements. Therefore, the phase of each coil unit in the N coil units cannot be determined from the calculation result. In this embodiment, after receiving the N digital magnetic resonance echo signals from the analog receiver, the mode matrix processor, during matrix operations, does not multiply by a mode matrix containing complex elements, but rather by an identity matrix. Thus, the calculation result is the original N digital magnetic resonance echo signals.

[0079] Step 302: The mode matrix processor calculates the measured phase of each of the N coil units participating in this magnetic resonance imaging scan based on each digital magnetic resonance echo signal in the calculation results.

[0080] Step 303: Based on the scanning direction of this magnetic resonance imaging, determine the spatial distribution of N coil units, and based on the spatial distribution of N coil units, determine the design phase of each coil unit in the N coil units.

[0081] Step 304: Randomly select one coil unit from the N coil units and calculate the difference between the designed phase and the measured phase of the selected coil unit.

[0082] Step 305: Add the difference to the measured phase of each of the N coil units to obtain the regularized measured phase of each coil unit.

[0083] Figure 4 This is a schematic diagram illustrating the spatial distribution of six coil units (E7U, E8U, E9U, E7L, E8L, and E9L) designed for this magnetic resonance imaging scan, based on the current scan direction, in an application example of the present invention. The coil units are spaced 60° apart, and their designed phases are 150°, 90°, 30°, -30°, 270°, and 210°, respectively. It should be noted that once the magnetic resonance scan direction is determined, the spatial distribution of each coil unit matching that scan direction can be designed. Once the spatial distribution of each coil unit is designed, the relative spatial positions between the coil units are determined, and thus the designed phase of each coil can be determined. The designed phase value of each coil does not need to be fixed; it only needs to match the relative positions between the coil units. For example, the designed phases of the above 6 coil units: E7U, E8U, E9U, E7L, E8L, and E9L are a°, (a-60)°, (a-120)°, (a-180)°, (a+120)°, and (a+60)°, respectively. The value of a satisfies the condition that the designed phases of these 6 coil units are all within the range of [-360°, 360°].

[0084] Figure 5 The amplitude and phase diagrams of the magnetic resonance echo images acquired by six coil units: E7U, E8U, E9U, E7L, E8L, and E9L are shown. 511–516 represent the amplitude diagrams of the magnetic resonance echo images acquired by E7U, E8U, E9U, E7L, E8L, and E9L, respectively, while 521–526 represent the phase diagrams of the magnetic resonance echo images acquired by E7U, E8U, E9U, E7L, E8L, and E9L, respectively. Based on the phase diagrams of each coil unit, the measured phases of each coil unit are calculated to be 68.28°, 10.47°, -59.74°, -116°, 179.23°, and 135.46°, respectively. Selecting one coil unit, let's say E8U, the phase difference between the designed phase (90°) and the measured phase (10.47°) of E8U is calculated as: 90° - 10.47° = 79.53°.

[0085] Adding 79.53° to the measured phase of each coil unit yields the following regularized measured phase for each coil unit:

[0086] E8U: 10.47°+79.53°=90°;

[0087] E7U: 68.28°+79.53°=147.81°;

[0088] E9U: -59.74°+79.53°=19.79°;

[0089] E7L: -116°+79.53°=-36.47°;

[0090] E8L: 179.23°+79.53°=258.76°;

[0091] E9L: 135.46°+79.53°=214.99°.

[0092] Step 306: For each of the N coil units, determine whether the difference between the regularized measured phase and the designed phase of the coil unit is within a preset range. If yes, determine that the coil unit has passed the phase calibration check; otherwise, determine that the coil unit has failed the phase calibration check and notify the user.

[0093] If a user learns that a coil unit has failed the phase calibration check, the user can recalibrate the coil phase or / and the system phase.

[0094] Figure 6 This is a schematic diagram of the phase calibration and inspection device provided in an embodiment of the present invention. The device mainly includes:

[0095] The matrix calculation module 61 is used to multiply the N digital magnetic resonance echo signals from the analog receiver of the magnetic resonance imaging system by the identity matrix and send the calculation results to the measurement phase calculation module 62.

[0096] The measurement phase calculation module 62 is used to calculate the measurement phase of each of the N coil units participating in this magnetic resonance scan based on each digital magnetic resonance echo signal in the calculation result of the matrix calculation module 61, and send the measurement phase of each of the N coil units to the inspection module 64.

[0097] The phase determination module 63 is designed to determine the spatial distribution of N coil units participating in the current magnetic resonance scan that match the current scan direction, determine the design phase of each coil unit in the N coil units based on the spatial distribution of the N coil units, and send the design phase of each coil unit in the N coil units to the inspection module 64.

[0098] The inspection module 64 is used to compare the measured phase with the designed phase of each of the N coil units, and determine whether each coil unit passes the phase calibration check based on the comparison results.

[0099] In one optional embodiment, before the inspection module 64 compares the measured phase with the designed phase of each of the N coil units, it is further configured to: arbitrarily select one coil unit from the N coil units, calculate the difference between the designed phase and the measured phase of the selected coil unit; and add the difference to the measured phase of each of the N coil units to obtain the regularized measured phase of each coil unit.

[0100] The inspection module 64 compares the measured phase with the designed phase of each of the N coil units, including: calculating the difference between the regularized measured phase and the designed phase of each of the N coil units;

[0101] The inspection module 64 determines whether each coil unit passes the phase calibration check based on the comparison results, including: for each coil unit among the N coil units, if the difference between the measured phase and the designed phase of the coil unit is within a preset range, then the coil unit is determined to have passed the phase calibration check; otherwise, the coil unit is determined to have failed the phase calibration check.

[0102] In one optional embodiment, after the inspection module 64 determines whether each coil unit has passed the phase calibration check based on the comparison results, it is further configured to: if any coil unit fails the phase calibration check, notify the user to re-perform coil phase calibration or / and system phase calibration.

[0103] In one alternative embodiment, the above-described device is located in the pattern matrix processor of the magnetic resonance imaging system.

[0104] The magnetic resonance imaging system proposed in this embodiment of the invention may include the phase calibration inspection device provided in the above embodiment.

[0105] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A phase calibration check method, characterized in that, include: Multiply the N digital magnetic resonance echo signals from the analog receiver of the magnetic resonance imaging system by the identity matrix, where N is a positive integer; Based on each digital magnetic resonance echo signal in the calculation results, the measured phase of each of the N coil units participating in this magnetic resonance scan is calculated. Based on the direction of this magnetic resonance scan, determine the spatial distribution of the N coil units that match the direction of this magnetic resonance scan, and based on the spatial distribution of the N coil units, determine the design phase of each of the N coil units; The measured phase of each of the N coil units is compared with the designed phase, and the phase calibration check is determined based on the comparison results.

2. The method of claim 1, wherein, After determining the design phase of each of the N coil units, and before comparing the measured phase of each of the N coil units with the design phase, the process further includes: Arbitrarily select one coil unit from the N coil units, and calculate the difference between the design phase and the measurement phase of the selected coil unit; add the difference to the measurement phase of each of the N coil units to obtain the regularized measurement phase of each coil unit; The step of comparing the measured phase with the designed phase of each of the N coil units includes: Calculate the difference between the regularized measured phase and the design phase for each of the N coil units; The step of determining whether each coil unit passes the phase calibration check based on the comparison results includes: For each of the N coil units, if the difference between the measured phase and the designed phase of the coil unit is within a preset range, then the coil unit is determined to have passed the phase calibration check; otherwise, the coil unit is determined to have failed the phase calibration check.

3. The method of claim 1, wherein, After determining whether each coil unit has passed the phase calibration check based on the comparison results, the process further includes: If any coil unit fails the phase calibration check, the user will be notified to recalibrate the coil phase or / and the system phase.

4. A phase calibration checking apparatus characterized by comprising: include: The matrix calculation module (61) is used to multiply the N digital magnetic resonance echo signals from the analog receiver of the magnetic resonance imaging system by the identity matrix, where N is a positive integer; The measurement phase calculation module (62) is used to calculate the measurement phase of each of the N coil units participating in this magnetic resonance scan based on each digital magnetic resonance echo signal in the calculation result of the matrix calculation module (61). The design phase determination module (63) is used to determine the spatial distribution of the N coil units that match the current scanning direction according to the current scanning direction, and to determine the design phase of each coil unit in the N coil units according to the spatial distribution of the N coil units. The inspection module (64) is used to compare the measured phase with the designed phase of each of the N coil units respectively, and determine whether each coil unit passes the phase calibration inspection based on the comparison results.

5. The apparatus of claim 4, wherein, Before comparing the measured phase with the designed phase of each of the N coil units, the inspection module (64) is further used for: Arbitrarily select one coil unit from the N coil units, and calculate the difference between the design phase and the measured phase of the selected coil unit; add the difference to the measured phase of each of the N coil units to obtain the regularized measured phase of each coil unit; The inspection module (64) compares the measured phase with the designed phase of each of the N coil units, including: Calculate the difference between the regularized measured phase and the design phase for each of the N coil units; The inspection module (64) determines whether each coil unit passes the phase calibration check based on the comparison results, including: For each of the N coil units, if the difference between the measured phase and the designed phase of the coil unit is within a preset range, then the coil unit is determined to have passed the phase calibration check; otherwise, the coil unit is determined to have failed the phase calibration check.

6. The apparatus of claim 4, wherein, After the inspection module (64) determines whether each coil unit has passed the phase calibration check based on the comparison results, it is further used for: If any coil unit fails the phase calibration check, the user will be notified to recalibrate the coil phase or / and the system phase.

7. The apparatus of claim 4, wherein, The device is located in the mode matrix processor of the magnetic resonance imaging system.

8. A magnetic resonance imaging system, characterized by Includes the apparatus as described in any one of claims 4 to 7.

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