MRI processing apparatus and method, and a computer-readable recording medium on which a program for performing the method is stored.

Abstract

An MRI processing apparatus and method, and a computer-readable recording medium storing a program for performing the method are disclosed. An MRI processing apparatus according to one embodiment of the present invention may include, as an MRI processing apparatus for generating LGE (Late Gadolinium Enhancement) MRI, a storage medium for storing ECV (extracellular volume), a numerical value of the volume ratio of red blood cells in the blood, the T1 value of cardiac muscle before contrast agent injection, the T1 value of blood before contrast agent injection, and the T1 value of blood after contrast agent injection, and a processor that calculates the T1 value of cardiac muscle after contrast agent injection based on the correlation between the ECV, the numerical value of the volume ratio of red blood cells in the blood, the T1 value of cardiac muscle before contrast agent injection, the T1 value of blood before contrast agent injection, and the T1 value of blood after contrast agent injection, and calculates the optimal reversal time of the MRI using the calculated T1 value of cardiac muscle after contrast agent injection.

Description

Technical Field

[0001] The present invention relates to an MRI processing apparatus and method, and a computer-readable recording medium storing a program for executing the method. More specifically, the present invention relates to an MRI processing apparatus and method for generating late gadolinium enhancement (LGE) MRI, and a computer-readable recording medium storing a program for executing the method.

Background Art

[0002] Magnetic resonance imaging (MRI) refers to a diagnostic examination in which an RF (Radio Frequency) pulse is transferred to a subject's body while the subject is positioned in a strong magnetic field, and the resonating magnetic field is measured to obtain an image. The advantage of MRI is that it is harmless to the human body compared to X-ray imaging or CT that utilize radiation because it uses RF pulses and magnetic fields, and information on soft tissues can be obtained in various ways.

[0003] Among various MRI techniques, late gadolinium enhancement (LGE) MRI is effective in diagnosing myocardial lesions. Late gadolinium enhancement MRI utilizes the tendency for a contrast agent to remain longer in myocardial lesions than in normal myocardium. More specifically, late gadolinium enhancement MRI is obtained based on the difference in the intensity of the video signal between normal myocardium and lesions that appears in the MRI data within the time range in which, after the contrast agent is injected, the contrast agent in the normal myocardium is relatively largely excreted and a relatively large amount of the contrast agent remains in the lesions, so that the presence or absence of lesions can be determined.

[0004] After the contrast agent is injected, the contrast agent in the normal myocardium is relatively largely excreted, and the time when a large amount of the contrast agent remains in the lesions and the enhancement effect appears is about several seconds, which is short. Also, the intensity of the video signal of the normal myocardium and lesions that appears in the MRI within about several seconds changes continuously.

[0005] For accurate diagnosis of a lesion, an MRI image is needed at the point when a relatively large amount of contrast agent is drained from the normal myocardium and a large amount of contrast agent remains in the lesion, resulting in a difference in shadowing between the normal myocardium and the lesion exceeding a certain level. However, to date, no technology has been demonstrated that can accurately capture and visualize the point at which a relatively large amount of contrast agent is drained from the normal myocardium and a large amount of contrast agent remains in the lesion, resulting in a difference in shadowing between the normal myocardium and the lesion exceeding a certain level on MRI. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Korean Published Patent No. 10-2022-0030896, Specification: "Method for correcting magnetic resonance imaging errors using heart rate intervals," published March 11, 2022. [Overview of the project] [Problems that the invention aims to solve]

[0007] The object of the present invention is to provide an MRI processing apparatus and method that automatically calculates the point in time at which the difference in shadow between normal tissue and a lesion exceeds a certain level in delayed enhancement (LGE) MRI, and to acquire the MRI image at that point in time through post-processing using a post-T1 map, as well as a computer-readable recording medium on which a program for performing the method is stored.

[0008] The problems addressed by the present invention are not limited to those mentioned above, and any other problems not mentioned can be clearly understood by an ordinary person skilled in the art from the following description. [Means for solving the problem]

[0009] According to one aspect of the present invention, an MRI processing device is provided for generating LGE (Late Gadolinium Enhancement) MRI (Magnetic Resonance Imaging), which includes a storage medium for storing ECV (extracellular volume), the volume ratio value of red blood cells in the blood, the T1 value of cardiac muscle before contrast agent injection, the T1 value of blood before contrast agent injection, and the T1 value of blood after contrast agent injection; and a processor that calculates the T1 value of cardiac muscle after contrast agent injection based on the correlation between the ECV, the volume ratio value of red blood cells in the blood, the T1 value of cardiac muscle before contrast agent injection, the T1 value of blood before contrast agent injection, and the T1 value of blood after contrast agent injection, and calculates the optimal inversion time of the MRI using the calculated T1 value of cardiac muscle after contrast agent injection.

[0010] In an MRI processing apparatus according to one aspect of the present invention, the processor can calculate the T1 value of the cardiac muscle after the injection of the contrast agent based on the following mathematical formula [Equation 1].

number

[0011] In an MRI processing apparatus according to one aspect of the present invention, the ECV can have a value selected in the range of 24 to 28%.

[0012] In an MRI processing apparatus according to one aspect of the present invention, the volume percentage value of red blood cells in the blood can be a value selected within the range of 38 to 42%.

[0013] In an MRI processing apparatus according to one aspect of the present invention, the processor can calculate the optimal reversal time by substituting the T1 value of the cardiac muscle after the injection of the contrast agent into the following mathematical formula [Equation 2].

number

[0014] In an MRI processing apparatus according to one aspect of the present invention, the processor can normalize the video signal included in the MRI data at the optimal inversion point using the following mathematical formula [Equation 3] to generate a normalized video signal.

number

[0015] In an MRI processing apparatus according to one aspect of the present invention, the processor can determine that a portion of the MRI at the optimal inversion point in which the normalized MRI signal appears to be above a reference value is a lesion.

[0016] According to another aspect of the present invention, as an MRI processing method for generating LGE (Late Gadolinium Enhancement) MRI (Magnetic Resonance Imaging), a storage medium stores an ECV (extracellular volume), a volume fraction value of red blood cells in blood, a T1 value of cardiac muscle before contrast agent injection, a T1 value of blood before contrast agent injection, and a T1 value of blood after contrast agent injection, and a processor calculates a T1 value of cardiac muscle after contrast agent injection based on a correlation relationship among the ECV, the volume fraction value of red blood cells in blood, the T1 value of cardiac muscle before contrast agent injection, the T1 value of blood before contrast agent injection, and the T1 value of blood after contrast agent injection, and calculates an optimal inversion time of MRI using the calculated T1 value of cardiac muscle after contrast agent injection. An MRI processing method including these steps is provided.

[0017] In the MRI processing method according to another aspect of the present invention, in the step of calculating the optimal inversion time, the processor can calculate the T1 value of cardiac muscle after contrast agent injection based on the following [Equation 1]. JPEG2026510400000005.jpg26133 (T1_Post_Myo: T1 value of cardiac muscle after contrast agent injection, HCT: volume fraction value of red blood cells in blood, T1_Pre_Myo: T1 value of cardiac muscle before contrast agent injection, T1_Pre_Blood: T1 value of blood before contrast agent injection, T1_Post_Blood: T1 value of blood after contrast agent injection).

[0018] In the MRI processing method according to another aspect of the present invention, the ECV can have a value selected in the range of 24 to 28%.

[0019] In the MRI processing method according to another aspect of the present invention, the volume fraction value of red blood cells in blood can have a value selected in the range of 38 to 42%.

[0020] In the MRI processing method according to another aspect of the present invention, in the step of calculating the optimal inversion time, the processor can calculate the optimal inversion time by substituting the T1 value of the cardiac muscle after the injection of the contrast agent into the following [Equation 2]. JPEG2026510400000006.jpg16128 (TI_optimal: Optimal inversion time of MRI, T1_Post_Myo: T1 value of cardiac muscle after injection of contrast agent).

[0021] The MRI processing method according to another aspect of the present invention may further include a step in which the processor normalizes the video signal included in the MRI data at the optimal inversion time using the following [Equation 3] to generate a normalized video signal. JPEG2026510400000007.jpg16128 (S_normal: Normalized video signal, S_TI_optimal: Video signal included in MRI data at the optimal inversion time, A is a real number greater than or equal to 1).

[0022] The MRI processing method according to another aspect of the present invention may further include a step in which the processor determines, as a lesion, a portion where the normalized MRI signal appears above a reference value on the MRI at the optimal inversion time.

[0023] According to still another aspect of the present invention, there is provided a non-transitory computer-readable storage medium storing a program including at least one instruction for performing the MRI processing method.

Advantages of the Invention

[0024] With the above configuration, the MRI processing apparatus and method according to the present invention, and the computer-readable recording medium storing the program for performing the method accurately calculate the time point when the difference in shading between normal tissue and lesions appears maximally on delayed contrast-enhanced (LGE) MRI, and enable efficient acquisition of MRI at that time point.

[0025] The effects of the present invention are not limited to those described above, but should be understood to include all effects that can be inferred from the configuration of the invention as described in the detailed description or claims. [Brief explanation of the drawing]

[0026] [Figure 1] This is a configuration diagram of an MRI processing apparatus according to one embodiment of the present invention. [Figure 2] This is a simplified diagram showing the heart of a subject with a lesion in the cardiac muscle, on a horizontal plane. [Figure 3] This graph shows the MRI signal intensity of normal and lesional tissues over time, with relatively more contrast agent remaining in the lesional tissue than in the normal tissue after the contrast agent has been injected. [Figure 4] This is a flowchart of an MRI processing method according to one embodiment of the present invention. [Modes for carrying out the invention]

[0027] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings, so that those skilled in the art to which the present invention pertains can easily implement them. The present invention may be embodied in various different forms and is not limited to the embodiments described herein. For the sake of clarity in illustrating the present invention, parts not relevant to the description have been omitted from the drawings, and the same or similar reference numerals have been used throughout the specification for identical or similar components.

[0028] Words and terms used in this specification and claims should not be interpreted in a manner limited to their ordinary or dictionary meanings, but rather in a manner and concept consistent with the technical idea of ​​the present invention, in accordance with the principle that inventors may define terms and concepts in order to best describe their invention.

[0029] In this specification, terms such as “includes” or “having” are intended to describe the presence of features, figures, stages, operations, components, parts, or combinations thereof as described in the specification, and should be understood not to preemptively exclude the possibility of the presence or addition of one or more other features, figures, stages, operations, components, parts, or combinations thereof.

[0030] Figure 1 is a diagram showing the configuration of an MRI processing apparatus according to one embodiment of the present invention.

[0031] An MRI (Magnetic Resonance Image) processing device 100 according to one embodiment of the present invention is for LGE MRI (Late Gadolinium Enhancement Magnetic Resonance Imaging). In other words, an MRI processing device 100 according to one embodiment of the present invention is for obtaining delayed enhancement (LGE) MRI using a gadolinium-based contrast agent. Hereinafter, the contrast agent may mean a contrast agent containing gadolinium.

[0032] Furthermore, the MRI processing device 100 according to one embodiment of the present invention can generate T1-weighted MRI for the diagnosis of intramyocardial lesions. More specifically, the MRI processing device 100 according to one embodiment of the present invention may be used to generate synLGE (synthetic late gadolinium enhancement) images using a post-T1 MRI map after contrast agent injection.

[0033] Here, an MRI post-T1 map refers to a collection of MRI data in which the signal intensity changes of each MRI pixel over a predetermined period of time are cumulatively stored after the injection of contrast agent into the subject. More specifically, an MRI post-T1 map can be defined as a collection of T1 values ​​for each individual MRI pixel.

[0034] The T1 value represents the time it takes for rotating protons, aligned by a magnetic field formed within the MRI device, to realign with the magnetic field after being reversed by an RF pulse. More specifically, the T1 value can be defined as the time required from the time the protons are reversed after an RF pulse is injected while they are aligned in the magnetic field, until the component of magnetization in the vertical axis direction (Z axis) reaches 63% of the maximum magnetization value in the initial aligned state of the protons.

[0035] In one embodiment of the present invention, the MRI post-T1 map may be defined as a set of MRI individual pixel signal intensity data at any point in a predetermined time interval after contrast agent administration. In other words, the MRI post-T1 map may include MRI individual pixel signal intensity data at any point in a predetermined time interval after contrast agent administration.

[0036] Referring to Figure 1, an MRI processing apparatus 100 according to one embodiment of the present invention is an MRI processing apparatus related to T1-weighted MRI generation and may include a storage medium 110 and a processor 120.

[0037] The storage medium 110 stores extracellular volume (ECV), the volume percentage of red blood cells in the blood, the T1 value of cardiac muscle before contrast agent injection, the T1 value of blood before contrast agent injection, and the T1 value of blood after contrast agent injection.

[0038] The storage medium 110 can be magnetic media such as hard disks, floppy disks, and magnetic tapes; optical media such as CD-ROMs (Compact Disk Read Only Memory) and DVDs (Digital Video Disks); magneto-optical media such as floppy disks; ROM, RAM, flash memory, etc.

[0039] The aforementioned ECV refers to the space or volume of tissue in the subject's body that is not occupied by cells. In relation to the subject's myocardium, the ECV may reflect the collagen content within the myocardium.

[0040] In a normal person, the ECV has a constant value, unaffected by MRI and imaging conditions. Based on this fact, the ECV can be pre-set. In other words, the ECV can be determined by a pre-set value rather than a measured value. For example, the ECV can have a value selected in the range of 24-28%. More specifically, the ECV can be set to 26%.

[0041] The aforementioned volume percentage of red blood cells in the blood represents the percentage of volume occupied by red blood cells in the subject's blood. Blood consists of plasma and serum, and serum contains red blood cells, white blood cells, and platelets. The aforementioned volume percentage of red blood cells in the blood represents the ratio of the volume occupied by red blood cells to the total volume of blood.

[0042] In one embodiment of the present invention, the volume percentage value of red blood cells in the blood may be a value measured for a subject undergoing an MRI examination.

[0043] On the other hand, based on the fact that the measured value of the volume percentage of red blood cells in the blood generally does not vary significantly from person to person, the volume percentage of red blood cells in the blood can be determined by a predetermined value. For example, the volume percentage of red blood cells in the blood can be a value selected within the range of 38-42%. More specifically, the volume percentage of red blood cells in the blood can be determined to be 40%.

[0044] In relation to the T1 values ​​of cardiac muscle before contrast agent injection, the T1 values ​​of blood before contrast agent injection, and the T1 values ​​of blood after contrast agent injection, the T1 value represents the time it takes for rotating protons to realign with the magnetic field after being reversed by an RF pulse while aligned by the magnetic field formed within the MRI apparatus. As mentioned above, the T1 value can be defined as the time required from the time it takes for the component of magnetization in the vertical axis direction (Z axis) to reach 63% of the maximum magnetization value in the initial alignment state of the protons after the RF pulse is injected while the protons are aligned in the magnetic field, causing the alignment of the protons to reverse.

[0045] On the other hand, the T1 value of cardiac muscle before contrast agent administration refers to the T1 value of cardiac muscle that appears during MRI imaging when the contrast agent has not been administered to the subject. Furthermore, the T1 value of blood before contrast agent administration refers to the T1 value of blood that appears in the subject before the contrast agent is administered. Furthermore, the T1 value of blood after contrast agent administration refers to the T1 value of blood that appears when the contrast agent remains in the subject's blood.

[0046] In one embodiment of the present invention, the T1 values ​​of cardiac muscle before contrast agent administration, the T1 values ​​of blood before contrast agent administration, and the T1 values ​​of blood after contrast agent administration may be measured and determined. That is, the T1 values ​​of cardiac muscle before contrast agent administration, the T1 values ​​of blood before contrast agent administration, and the T1 values ​​of blood after contrast agent administration may be measured and determined for the subject.

[0047] The processor 120 calculates the T1 value of the cardiac muscle after contrast agent injection based on the correlation between the ECV, the volume percentage value of red blood cells in the blood, the T1 value of the cardiac muscle before contrast agent injection, the T1 value of the blood before contrast agent injection, and the T1 value of the blood after contrast agent injection. Using the calculated T1 value of the cardiac muscle after contrast agent injection, the processor 120 calculates the optimal inversion time for MRI.

[0048] Figure 2 is a simplified diagram of the heart of a subject with a lesion in the cardiac muscle, shown on a horizontal plane.

[0049] Referring to Figure 2, the heart 10 includes myocardium 11 and ventricles 12 formed within the myocardium 11. Blood may be stored in the ventricles 12. At this time, a lesion 13 may be present in the myocardium 11.

[0050] As described above, the MRI processing apparatus 100 according to one embodiment of the present invention may be for performing delayed enhancement (LGE) MRI. Delayed enhancement (LGE) MRI takes advantage of the tendency for gadolinium-based contrast agents to remain in intramyocardial lesions 13 longer than in normal myocardium 11.

[0051] Delayed-enhancement MRI allows for the determination of the presence or absence of a lesion based on the difference in the intensity of the image signals between the normal myocardium 11 and the lesion 13, which are obtained in MRI data obtained during the time period when most of the contrast agent has been drained from the normal myocardium 11 after the contrast agent has been injected, and a large amount of contrast agent remains in the myocardial lesion 13.

[0052] Synthetic delayed enhancement (synLGE) MRI allows for the determination of the presence or absence of a lesion based on the difference in the intensity of the image signals between normal myocardium 11 and lesion 13, as seen in one or more MRI data obtained during a time period in which a relatively larger amount of contrast agent remains in the lesion 13 than in normal myocardium 11 after the contrast agent has been injected. In this case, the MRI data may be obtained from the post-T1 map described above. That is, synthetic delayed enhancement MRI can be derived from the post-T1 map.

[0053] Figure 3 is a graph showing the MRI signal intensity of normal and lesional tissue over time, with a relatively larger amount of contrast agent remaining in the lesional tissue compared to the normal tissue after contrast agent injection. More specifically, Figure 3 is a graph showing the MRI signal intensity of normal and lesional tissue over time, with most of the contrast agent being excreted from the normal tissue and a relatively larger amount remaining in the lesional tissue after contrast agent injection. In Figure 3, negative signal intensities are displayed as positive inversions.

[0054] Referring to Figure 3, after contrast agent injection, the contrast agent is expelled from the normal myocardium 11, and the intensity of the image signals of the normal myocardium and the lesion in the MRI data continuously changes during the time (T) when a large amount of contrast agent remains in the lesion 13. When attempting to determine the presence or absence of a lesion by normalizing (or amplifying) the image signals of the MRI data obtained at a specific point in time, it is preferable to acquire the MRI data at the point in time (TI_optimal) when the absolute value of the intensity of the image signal of the normal myocardium is at its minimum (for example, the intensity of the image signal is 0), or to acquire the T1 image at that point in time.

[0055] As illustrated in Figure 3, at the point in LGE where the absolute value of the image signal intensity of normal myocardium appears as the minimum value S1 (TI_optimal), the absolute value of the image signal intensity of the lesion (S2) appears to be greater than that of normal myocardium. When the image signals of the MRI data obtained at this point (TI_optimal) are normalized (or amplified), normal myocardium will appear darker on the MRI, and lesions will appear brighter. Therefore, the presence or absence of a lesion, and if a lesion exists, its location, can be accurately determined through the MRI data at that point in time.

[0056] Therefore, in one embodiment of the present invention, the optimal inversion time (TI_optimal) can be defined as the time (T) after contrast agent injection during which a relatively larger amount of contrast agent remains in the lesion 13 than in the normal myocardium 11, at which point the intensity of the image signal of the normal myocardium included in the MRI data appears to be at its minimum. In other words, the optimal inversion time (TI_optimal) can be the time at which the absolute value of the intensity of the image signal of the normal myocardium included in the MRI data appears to be at its minimum value (for example, 0).

[0057] Theoretically, it is preferable that the minimum value be 0. However, considering normalization (or amplification), the minimum value may be arbitrarily determined within a predetermined range. In other words, the optimal inversion time (TI_optimal) may be defined as a time point arbitrarily selected within the time interval in which the intensity of the video signal of normal myocardium appears within the predetermined range.

[0058] For example, in relation to the minimum value, the predetermined range can be set to a range in which the value obtained by normalizing (or amplifying) the intensity of the video signal for normal myocardium appears to be 70 to 80 or less. Furthermore, the optimal inversion point can be arbitrarily selected within the time interval in which the intensity of the video signal for normal myocardium appears to be within the predetermined range.

[0059] In relation to the calculation of the optimal spotting time, the processor 120 can calculate the T1 value of the cardiac muscle after contrast agent injection based on the following [Equation 1]. JPEG2026510400000008.jpg27144 (T1_Post_Myo: T1 value of cardiac muscle after contrast agent injection, HCT: volume percentage of red blood cells in the blood, T1_Pre_Myo: T1 value of cardiac muscle before contrast agent injection, T1_Pre_Blood: T1 value of blood before contrast agent injection, T1_Post_Blood: T1 value of blood after contrast agent injection).

[0060] As will be described later, the T1 value of the cardiac muscle after contrast agent injection is necessary to calculate the optimal reversal time. Here, cardiac muscle refers to normal tissue, and the T1 value of the cardiac muscle after contrast agent injection means the T1 value of the cardiac muscle that appears when the contrast agent is injected and remains within the cardiac muscle. As mentioned above, the T1 value can be defined as the time from when the RF pulse is injected and the proton alignment is reversed until the average magnetization of 63% of the initial state is restored in the longitudinal axis direction.

[0061] The time that the contrast agent remains in the cardiac muscle after injection is very short, only a few seconds. Therefore, it is practically very difficult to measure the T1 value of the cardiac muscle after the injection of the contrast agent.

[0062] In one embodiment of the present invention, the processor 120 calculates the T1 value of the cardiac muscle after the injection of the contrast agent through [Equation 1]. Accordingly, in the present invention, the T1 value of the cardiac muscle after the injection of the contrast agent, which is substantially very difficult to measure, can be accurately calculated through calculation, and the optimal inversion time can be accurately calculated as described below.

[0063] The processor 120 can calculate the optimal reversal time by substituting the T1 value of the cardiac muscle after the injection of the contrast agent into the following [Equation 2]. JPEG2026510400000009.jpg16128 (TI_optimal: optimal inversion time, T1_Post_Myo: T1 value of cardiac muscle after contrast agent injection).

[0064] Furthermore, the processor 120 normalizes the video signals included in the MRI data at the optimal inversion time (TI_optimal) using [Equation 3] below to generate a normalized video signal. More specifically, the processor 120 can select the MRI data at the optimal inversion time (TI_optimal) from the MRI data included in the post-T1 map and normalize each pixel's video signal of the corresponding MRI data using [Equation 3]. JPEG2026510400000010.jpg16128 (S_normal: normalized video signal, S_TI_optimal: video signal included in MRI data at the optimal inversion point, A is a real number greater than or equal to 1).

[0065] In this case, A in [Equation 3] above can be determined by the required level of signal normalization. For example, A could be 1000. Of course, this is illustrative, and A can be increased or decreased indefinitely depending on the required level of normalization (or amplification).

[0066] With protons aligned within a magnetic field, the absolute value of the MRI image signal for normal myocardium follows the following mathematical formula [Equation 4] during the process of proton alignment being reversed after an RF pulse is injected and then restored.

number

[0067] When the optimal inversion time (TI_optimal) is substituted for TI in [Equation 4], the signal intensity appears as 0. Therefore, when the processor 120 normalizes (or amplifies) the video signal (absolute value of the video signal intensity) included in the MRI data at the optimal inversion time, the signal intensity of the normal myocardial portion is not substantially amplified, while the signal intensity of the lesional portion appears relatively high. Consequently, the normal myocardial portion may appear dark and the lesional portion may appear bright in the MRI data obtained from the post-T1 map.

[0068] Furthermore, the processor 120 can identify areas in the MRI data at the optimal inversion time (TI_optimal) where the normalized MRI signal appears above a reference value as lesions. If there are no lesions in the patient's heart, even if the MRI data at the optimal inversion time (TI_optimal) is selected from the MRI data included in the post-T1 map and the image signal included in that MRI data is normalized, no regions where the image signal is greatly amplified may appear. Taking these points into consideration, the processor 120 can identify areas in the MRI data where the normalized MRI signal appears above a reference value as lesions.

[0069] In this case, the reference value can be appropriately determined based on the MRI device, imaging environment, etc. For example, the reference value can be selected from 150 to 250. More specifically, the reference value can be 200.

[0070] On the other hand, the reference value can be stored in the storage medium 110. In other words, the reference value can be set in advance and stored in the storage medium 110.

[0071] The processor 120 can be a hardware unit that performs calculations and control within a computer. For example, the processor 120 may include at least one ALU (Arithmetic Logic Unit) and processing registers.

[0072] The following describes an MRI processing method according to one embodiment of the present invention.

[0073] Figure 4 is a flowchart of an MRI processing method according to one embodiment of the present invention.

[0074] Referring to Figure 4, the MRI processing method (S100) according to one embodiment of the present invention is an MRI processing method for generating LGE (Late Gadolinium Enhancement) MRI (Magnetic Resonance Imaging), and can be carried out as follows. The MRI processing method according to one embodiment of the present invention can be carried out by an MRI processing apparatus according to one embodiment of the present invention.

[0075] First, the storage medium 110 stores the extracellular volume (ECV), the volume percentage of red blood cells in the blood, the T1 value of cardiac muscle before contrast agent injection, the T1 value of blood before contrast agent injection, and the T1 value of blood after contrast agent injection (S110).

[0076] In one embodiment of the present invention, the ECV may be determined to a preset value rather than a measured value. For example, the ECV may have a value selected in the range of 24-28%. More specifically, the ECV may be determined to 26%.

[0077] Furthermore, the volume percentage value of red blood cells in the blood can be determined to a predetermined value. For example, the volume percentage value of red blood cells in the blood can be a value selected within the range of 38-42%. More specifically, the volume percentage value of red blood cells in the blood can be determined to be 40%.

[0078] On the other hand, the T1 values ​​of cardiac muscle before contrast agent administration, blood before contrast agent administration, and blood after contrast agent administration may be measured values. That is, the T1 values ​​of cardiac muscle before contrast agent administration, blood before contrast agent administration, and blood after contrast agent administration may be measured and determined for the subject.

[0079] Detailed information regarding the ECV value, the volume percentage value of red blood cells in the blood, the T1 value of cardiac muscle before contrast agent administration, the T1 value of blood before contrast agent administration, and the T1 value of blood after contrast agent administration is as described above.

[0080] Next, the processor 120 calculates the T1 value of the cardiac muscle after contrast agent administration based on the correlation between the ECV, the volume percentage value of red blood cells in the blood, the T1 value of the cardiac muscle before contrast agent administration, the T1 value of the blood before contrast agent administration, and the T1 value of the blood after contrast agent administration. Using the calculated T1 value of the cardiac muscle after contrast agent administration, the processor 120 calculates the optimal inversion time for MRI (S120).

[0081] In relation to the calculation of the optimal inversion time, the processor 120 can calculate the T1 value of the cardiac muscle after the injection of the contrast agent based on the following [Equation 1]. JPEG2026510400000012.jpg27144 (T1_Post_Myo: T1 value of cardiac muscle after contrast agent injection, HCT: volume percentage of red blood cells in the blood, T1_Pre_Myo: T1 value of cardiac muscle before contrast agent injection, T1_Pre_Blood: T1 value of blood before contrast agent injection, T1_Post_Blood: T1 value of blood after contrast agent injection).

[0082] As detailed above, the T1 value of the cardiac muscle after contrast agent injection is necessary to calculate the optimal reversal time. Here, cardiac muscle refers to normal tissue, and the T1 value of the cardiac muscle after contrast agent injection refers to the T1 value of the cardiac muscle that appears when the contrast agent is injected and remains within the cardiac muscle.

[0083] The T1 value of cardiac muscle after the injection of the contrast agent is practically difficult to measure. However, according to the present invention, the processor 120 can accurately calculate the T1 value of cardiac muscle after the injection of the contrast agent through [Equation 1].

[0084] The optimal reversal time can be accurately calculated using the T1 value of the cardiac muscle after the injection of the contrast agent, which was calculated as described above. Specifically, the processor 120 can calculate the optimal reversal time by substituting the T1 value of the cardiac muscle after the injection of the contrast agent into the following equation [Equation 2]. JPEG2026510400000013.jpg16128 (TI_optimal: Optimal inversion time for MRI, T1_Post_Myo: T1 value of cardiac muscle after contrast agent injection).

[0085] The aforementioned optimal inversion point can be defined as the point in time (T) after contrast agent injection when the intensity of the image signal of normal myocardium included in the MRI data is at its minimum, during which a relatively larger amount of contrast agent remains in the lesion 13 than in the normal myocardium 11. In other words, the aforementioned optimal inversion point can be the point in time when the absolute value of the intensity of the image signal of normal myocardium included in the MRI data appears as its minimum value (for example, 0).

[0086] As mentioned above, theoretically, it is preferable that the minimum value be 0. However, considering normalization (or amplification), the minimum value may be arbitrarily determined within a predetermined range. In other words, the optimal inversion time (TI_optimal) may be defined as a time point arbitrarily selected within the time interval in which the intensity of the video signal of normal myocardium appears within the predetermined range.

[0087] Next, the processor 120 normalizes the video signals included in the MRI data at the optimal inversion point using the following [Equation 3] to generate a normalized video signal (S130). More specifically, the processor 120 can normalize each pixel signal of the MRI data at the optimal inversion point (TI_optimal) among the MRI data included in the post-T1 map using [Equation 3]. JPEG2026510400000014.jpg16128 (S_normal: normalized video signal, S_TI_optimal: video signal included in MRI data at the optimal inversion point, A is a real number greater than or equal to 1).

[0088] In this case, A in [Equation 3] above can be determined by the required level of signal normalization. For example, A could be 1000. Of course, this is illustrative, and A can be increased or decreased indefinitely depending on the required level of normalization (or amplification).

[0089] When the processor 120 normalizes (or amplifies) the video signal (absolute value of the intensity of the video signal) contained in the MRI data at the optimal inversion point, the signal intensity of the normal myocardial portion is not substantially amplified, while the signal intensity of the lesional portion appears relatively high. Consequently, the normal myocardial portion may appear dark in the MRI image, while the lesional portion may appear bright.

[0090] Finally, the processor 120 determines that the portion of the MRI at the optimal inversion point in which the normalized MRI signal appears above a reference value is a lesion (S140). As described in detail above, when the processor 120 normalizes (or amplifies) the video signal (absolute value of the intensity of the video signal) included in the MRI data at the optimal inversion point, the signal intensity of the normal myocardial portion appears very low, while the signal intensity of the lesion portion appears relatively high. Based on this fact, the processor 120 can determine that the portion of the MRI data in which the normalized MRI signal appears above a reference value is a lesion.

[0091] The present invention also provides a non-transitory computer-readable storage medium on which a program containing at least one instruction for performing the MRI processing method according to the above-described embodiment is stored. In this case, the instruction may include not only machine code generated by a compiler but also high-level language code executable by a computer.

[0092] The storage medium may include magnetic media such as hard disks, floppy disks, and magnetic tapes; optical media such as CD-ROMs (Compact Disk Read Only Memory) and DVDs (Digital Video Disks); magneto-optical media such as floppy disks; and hardware devices configured to store and execute program instructions, such as ROMs, RAMs, and flash memory.

[0093] A non-transitory computer-readable storage medium according to one embodiment of the present invention can be placed (installed) in an MRI device and used.

[0094] According to the existing synLGE method, after contrast agent injection, an MRI post-T1 map (Post T1 map) is generated, which is a collection of signal intensity data for each MRI pixel at any given time point in time. The examiner (physician) then had to select the appropriate MRI data from the MRI post-T1 map to perform the diagnosis. In other words, with the conventional synLGE method, the selection of MRI data at an appropriate time point where the difference in contrast between normal tissue and lesions exceeds a certain level is performed passively. Consequently, there is a possibility of selecting MRI data at an inappropriate time point or of the selection of MRI data taking a long time.

[0095] However, in the present invention, after the injection of the contrast agent, the optimal inversion point is automatically calculated, which is the point in time when the intensity of the image signal of normal myocardium included in the MRI data is at its minimum during the time when a relatively large amount of contrast agent remains in the lesion compared to normal myocardium. In other words, the point in time when the intensity of the image signal of normal myocardium is at its minimum on the post-T1 map can be automatically calculated. Furthermore, by selecting and normalizing the MRI data at the optimal inversion point from the post-T1 map, the lesion can be identified quickly, accurately, and automatically.

[0096] While embodiments of the present invention have been described, the spirit of the invention is not limited by the embodiments presented herein. Those skilled in the art who understand the spirit of the invention will be able to easily propose other embodiments by adding, changing, deleting, or adding components, all within the same spirit, and these too can be said to fall within the spirit of the invention.

Claims

1. An MRI processing device for generating LGE (Late Gadolinium Enhancement) MRI (Magnetic Resonance Imaging), Storage medium for storing ECV (extracellular volume), volume percentage of red blood cells in the blood, T1 value of cardiac muscle before contrast agent injection, T1 value of blood before contrast agent injection, and T1 value of blood after contrast agent injection, and An MRI processing device comprising a processor that calculates the T1 value of the cardiac muscle after contrast agent injection based on the correlation between the ECV, the volume percentage value of red blood cells in the blood, the T1 value of the cardiac muscle before contrast agent injection, the T1 value of the blood before contrast agent injection, and the T1 value of the blood after contrast agent injection, and calculates the optimal inversion time for MRI using the calculated T1 value of the cardiac muscle after contrast agent injection.

2. The MRI processing apparatus according to claim 1, wherein the processor calculates the T1 value of the cardiac muscle after the injection of the contrast agent based on the following [Equation 1]. (T1_Post_Myo: T1 value of cardiac muscle after contrast agent injection, HCT: volume percentage of red blood cells in the blood, T1_Pre_Myo: T1 value of cardiac muscle before contrast agent injection, T1_Pre_Blood: T1 value of blood before contrast agent injection, T1_Post_Blood: T1 value of blood after contrast agent injection).

3. The MRI apparatus according to claim 1, wherein the ECV has a value selected in the range of 24 to 28%.

4. The MRI apparatus according to claim 1, wherein the volume percentage value of red blood cells in the blood is a value selected within the range of 38 to 42%.

5. The MRI processing apparatus according to claim 1, wherein the processor calculates the optimal reversal time by substituting the T1 value of the cardiac muscle after the injection of the contrast agent into the following [Equation 2]. (TI_optimal: optimal reversal time, T1_Post_Myo: T1 value of cardiac muscle after contrast agent injection).

6. The MRI processing apparatus according to claim 1, wherein the processor normalizes the video signal included in the MRI data at the optimal inversion point using the following [Equation 3] to generate a normalized video signal. (S_normal: normalized video signal, S_TI_optimal: video signal included in MRI data at the optimal inversion point, A is a real number greater than or equal to 1).

7. The MRI processing apparatus according to claim 6, wherein the processor determines that a portion of the MRI at the optimal inversion point in which the normalized MRI signal appears to be above a reference value is a lesion.

8. An MRI processing method for generating LGE (Late Gadolinium Enhancement) MRI (Magnetic Resonance Imaging), The storage medium is used to store ECV (extracellular volume), the volume percentage value of red blood cells in the blood, the T1 value of cardiac muscle before contrast agent injection, the T1 value of blood before contrast agent injection, and the T1 value of blood after contrast agent injection, and An MRI processing method comprising the steps of: a processor calculating the T1 value of the cardiac muscle after contrast agent injection based on the correlation between the ECV, the volume percentage value of red blood cells in the blood, the T1 value of the cardiac muscle before contrast agent injection, the T1 value of the blood before contrast agent injection, and the T1 value of the blood after contrast agent injection; and using the calculated T1 value of the cardiac muscle after contrast agent injection to calculate the optimal inversion time for the MRI.

9. The MRI processing method according to claim 8, wherein, in the step of calculating the optimal inversion time, the processor calculates the T1 value of the cardiac muscle after the injection of the contrast agent based on the following [Equation 1]. (T1_Post_Myo: T1 value of cardiac muscle after contrast agent injection, HCT: volume percentage of red blood cells in the blood, T1_Pre_Myo: T1 value of cardiac muscle before contrast agent injection, T1_Pre_Blood: T1 value of blood before contrast agent injection, T1_Post_Blood: T1 value of blood after contrast agent injection).

10. The MRI processing method according to claim 8, wherein the ECV has a value selected in the range of 24 to 28%.

11. The MRI processing method according to claim 8, wherein the volume percentage value of red blood cells in the blood is a value selected within the range of 38 to 42%.

12. The MRI processing method according to claim 8, wherein, in the step of calculating the optimal inversion time, the processor calculates the optimal inversion time by substituting the T1 value of the cardiac muscle after the injection of the contrast agent into the following [Equation 2]. (TI_optimal: Optimal inversion time for MRI, T1_Post_Myo: T1 value of cardiac muscle after contrast agent injection).

13. The MRI processing method according to claim 8, further comprising the step of the processor normalizing the video signal included in the MRI data at the optimal inversion point using the following [Equation 3] to generate a normalized video signal. (S_normal: normalized video signal, S_TI_optimal: video signal included in MRI data at the optimal inversion point, A is a real number greater than or equal to 1).

14. The MRI processing method according to claim 13, further comprising the step of the processor determining as a lesion a portion on the MRI at the optimal inversion point in which the normalized MRI signal appears to be above a reference value.

15. A non-transitor computer-readable storage medium on which a program comprising at least one instruction for performing the MRI processing method described in claim 8 is stored.

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