Magnetic resonance imaging-based extraocular muscle extracellular volume measurement system and method

Abstract

The invention discloses an extraocular muscle extracellular volume measurement system and method based on magnetic resonance imaging, and relates to the technical field of medical image processing and quantitative measurement, and the technical key points are as follows: obtaining enhanced T1mapping sequence horizontal axial image data comprising extraocular muscle after plain scanning and 10 minutes delay through MRI equipment; a region of interest used for calculating a T1 value is obtained on the extraocular muscle T1mapping image; calculating the longitudinal relaxation time (T1 value) of each pixel of the extraocular muscle based on the T1mapping sequence; the extracellular volume (ECV) is calculated through a formula according to the blood T1 value and the hematocrit parameter; and constructing an extraocular muscle three-dimensional model and visualizing ECV distribution. The method has the effects of breaking through the invasive limitation of traditional biopsy, accurately quantifying the extracellular volume of the extraocular muscle, and providing an important basis for diagnosing ocular muscle fibrosis, inflammatory pseudotumor, thyroid-related eye diseases and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of medical image processing and quantitative measurement, and particularly relates to a system and method for measuring the extracellular volume of extraocular muscles based on magnetic resonance imaging. Background Art

[0002] Extraocular muscle diseases such as thyroid-associated ophthalmopathy (TAO) can cause structural changes in extraocular muscle tissues, especially abnormal expansion or contraction of the extracellular volume.

[0003] T1 mapping is a magnetic resonance parametric imaging technique that can be used to measure the T1 relaxation time of tissues and calculate the ECV in combination with contrast-enhanced scanning. The ECV measurement based on T1 mapping has been applied in cardiac imaging, but it is not yet mature in the study of extraocular muscles. Summary of the Invention

[0004] The purpose of the present invention is to solve the above problems and provide a system and method for measuring the extracellular volume of extraocular muscles based on magnetic resonance imaging.

[0005] To achieve the above purpose, the technical solution of the present invention is as follows:

[0006] The present invention provides a system for measuring the extracellular volume of extraocular muscles based on magnetic resonance imaging, including a data acquisition module: performing magnetic resonance imaging scanning on the extraocular muscle cells of a patient to obtain magnetic resonance imaging data of the extraocular muscle cells;

[0007] An image preprocessing module: calculating the T1 value and quantifying the ECV of the magnetic resonance imaging data of the extraocular muscle cells to obtain preprocessed data;

[0008] A data export module: associating the T1 value and ECV data of the two-dimensional region of interest with the three-dimensional spatial coordinates in the DICOM file, and exporting the associated data to medical image processing software;

[0009] A three-dimensional modeling module: reconstructing a three-dimensional model of the associated data through the 3D Slicer medical image processing software.

[0010] The present invention is further configured as: taking the connection line between the external auditory meatus and the ipsilateral lateral canthus of the eye as the horizontal line of the orbit, making a plane cut parallel to this horizontal line, and cutting from the upper edge of the lower wall of the orbit to the lower edge of the upper wall of the orbit at a uniform interval and slice thickness to obtain continuous T1 mapping images of the extraocular muscles, and exporting the images in a fixed format as the medical image data.

[0011] The present invention is further configured to: adjust the appropriate window width and window level and apply pseudo-color to clearly display the T1 mapping images of the extraocular muscles at each axial plane, and manually delineate the regions of interest (ROIs) of the extraocular muscles; based on the boundaries of the initial ROIs, adopt a layer-by-layer slicing and manual adjustment method to accurately track the signal intensity difference interface between the extraocular muscles and the surrounding adipose tissue, adjust the boundaries of the ROIs of the extraocular muscles before and after enhancement, and confirm the positional consistency of the ROIs after correction; finally, form ROIs of each extraocular muscle that meet the requirements for T1 value calculation. Similarly, obtain the blood ROIs of the C6-7 segments of the internal carotid artery.

[0012] The present invention is further configured to: collect 2 mL of peripheral blood from the patient's cubital vein and store it using a blood collection tube containing an anticoagulant to prevent blood coagulation from affecting the detection accuracy. Centrifuge the collected blood sample at a speed of 3000 rpm for 10 minutes in a centrifuge. Read the hematocrit through a fully automatic blood analyzer.

[0013] The present invention is further configured to: the data export module establishes a mapping relationship between the spatial coordinate system in the DICOM tag and the pixel index, and stores the correlation matrix of the three-dimensional spatial coordinates and the T1 and ECV values using an octree data structure, supporting seamless docking with the 3DSlicer medical imaging platform.

[0014] The present invention is further configured to: use the 3D Slicer medical imaging software to generate a pseudo-color three-dimensional model based on the ECV value gradient, and simultaneously provide multi-planar reformation views in the axial, coronal, and sagittal planes.

[0015] The present invention also provides a method for measuring the extracellular volume of extraocular muscle cells based on magnetic resonance imaging, including: Step S1: Perform a T1 mapping plain scan to obtain the T1 mapping images of the extraocular muscles in magnetic resonance imaging;

[0016] Step S2: Perform an enhanced T1 mapping scan 10 minutes after injecting the gadolinium contrast agent to obtain the enhanced T1 mapping images of the extraocular muscles in magnetic resonance imaging;

[0017] Step S3: Draw the T1 mapping ROIs of the 8 extraocular muscles in the plain scan and enhancement respectively, as well as the T1 mapping ROI of the same C6-7 segment of the internal carotid artery, and record the corresponding T1 values;

[0018] Step S4: Substitute all the T1 values and the patient's hematocrit into the formula to calculate the extracellular volume of the extraocular muscles;

[0019] Step S5: According to the obtained T1 mapping images of the extraocular muscles, use the 3D Slicer medical imaging processing software to reconstruct the three-dimensional model of the associated data and establish a three-dimensional model of the extraocular muscles.

[0020] The present invention is further configured such that the formula for calculating the extracellular volume of the extraocular muscle is:

[0021]

[0022] where MRI = magnetic resonance imaging;

[0023]

[0024] represents the longitudinal relaxation rate;

[0025] EOM = extraocular muscle;

[0026] Hct = hematocrit;

[0027] T1 post = the T1 value measured when the tissue reaches a steady state 10 minutes after injecting the gadolinium contrast agent;

[0028] T1pro = the T1 value measured before injecting the gadolinium contrast agent.

[0029] Compared with the prior art, the beneficial effects of this solution are:

[0030] Break through the limitations of traditional biopsy methods and achieve non-invasive, accurate, and quantitative measurement of the extracellular volume of the extraocular muscle; adopt a standardized image acquisition and three-dimensional modeling process to enhance the repeatability between research and clinical practice; introduce a multi-module collaborative design to realize an integrated system for data acquisition, processing, and visualization, with good promotion value; the system has strong scalability and can be applied to the auxiliary diagnosis and efficacy evaluation of various orbit-related diseases. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is the T1 mapping plain scan sequence of the extraocular muscle in the embodiment of the present invention, where A is the T1 mapping plain scan sequence of the extraocular muscle, and B is the T1 mapping enhanced sequence of the extraocular muscle 10 minutes after injecting the gadolinium contrast agent

[0032] Figure 2 is the pseudo-color map of the T1 mapping plain scan sequence of the extraocular muscle in the embodiment of the present invention;

[0033] Figure 3 is the pseudo-color map of the T1 mapping enhanced sequence of the extraocular muscle in the embodiment of the present invention;

[0034] Figure 4 is the measurement of the T1 values of the plain scan and enhanced extraocular muscle and the C6-7 segment of the internal carotid artery in the embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0035] To enable those skilled in the art to better understand the solution of the present invention, the technical solution of the present invention will be further described in detail below in conjunction with the embodiments and drawings of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0036] It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below in conjunction with the embodiments.

[0037] Embodiment:

[0038] An extraocular muscle extracellular volume measurement system based on magnetic resonance imaging, comprising:

[0039] A data acquisition module: performing magnetic resonance imaging scanning on the extraocular muscle cells of a patient to obtain magnetic resonance imaging data of the extraocular muscle cells;

[0040] An image preprocessing module: calculating the T1 value and quantifying the ECV of the magnetic resonance imaging data of the extraocular muscle cells to obtain preprocessed data;

[0041] A data export module: associating the T1 value and ECV data of the two-dimensional region of interest with the three-dimensional spatial coordinates in the DICOM file, and exporting the associated data to medical image processing software;

[0042] A three-dimensional modeling module: reconstructing a three-dimensional model of the associated data through 3D Slicer medical image processing software.

[0043] In this embodiment, the data acquisition module uses the connection line between the external auditory meatus and the ipsilateral lateral canthus of the eye as the horizontal line of the orbit, makes a plane cut parallel to this horizontal line, and cuts from the upper edge of the lower wall of the orbit to the lower edge of the upper wall of the orbit at a uniform interval and slice thickness to obtain continuous extraocular muscle T1 mapping images, and exports the images in a fixed format as the medical image data.

[0044] In this embodiment, the window width and window level are adjusted appropriately and false colors are added to clearly display the extraocular muscle T1 mapping images of each axial plane, and the region of interest of the extraocular muscle is manually outlined; based on the boundary of the initial region of interest, the signal intensity difference interface between the extraocular muscle and the surrounding adipose tissue is accurately traced by means of manual adjustment of each slice, the boundary of the region of interest of the extraocular muscle before and after enhancement is adjusted, and the position consistency of the region of interest after correction is confirmed; finally, the region of interest of each extraocular muscle that meets the requirements for T1 value calculation is formed; similarly, the region of interest of the blood in the C6-7 segment of the internal carotid artery is obtained.

[0045] Collect 2 mL of peripheral blood from the patient's cubital vein and store it using a blood collection tube containing an anticoagulant to prevent blood clotting from affecting the detection accuracy; centrifuge the collected blood sample at a speed of 3000 rpm / min in a centrifuge for 10 minutes; read the hematocrit through a fully automatic blood analyzer.

[0046] In this embodiment, the data export module establishes a mapping relationship through the spatial coordinate system and pixel index in the DICOM tag, and stores the association matrix of three-dimensional spatial coordinates and T1 and ECV values using an octree data structure, supporting seamless docking with the 3DSlicer medical imaging platform.

[0047] In this embodiment, the 3D Slicer medical imaging software is used to generate a pseudo-color three-dimensional model based on the ECV value gradient, and at the same time provide multi-planar reformation views in the axial, coronal, and sagittal planes.

[0048] The present invention also provides a method for measuring the extracellular volume of extraocular muscles based on magnetic resonance imaging, including:

[0049] Step S1: Perform a T1 mapping plain scan to obtain a T1 mapping image of the extraocular muscles in magnetic resonance imaging;

[0050] Step S2: Perform an enhanced T1 mapping scan 10 minutes after injecting a gadolinium contrast agent to obtain an enhanced T1 mapping image of the extraocular muscles in magnetic resonance imaging;

[0051] Step S3: Draw the T1 mapping regions of interest for the 8 extraocular muscles in the plain scan and enhancement, as well as the C6-7 segment of the same internal carotid artery, and record the corresponding T1 values;

[0052] Step S4: Substitute all the T1 values and the patient's hematocrit into the formula to calculate the extracellular volume of the extraocular muscles;

[0053] Step S5: According to the obtained T1 mapping image of the extraocular muscles, use the 3D Slicer medical imaging processing software to reconstruct the three-dimensional model of the associated data and establish a three-dimensional model of the extraocular muscles.

[0054] In this embodiment, as Figure 1 shown, both the plain scan and enhanced T1 mapping sequences use the line connecting the external auditory meatus and the ipsilateral lateral canthus of the eye as the horizontal line of the orbit, make a plane cut parallel to this horizontal line, and cut from the upper edge of the lower wall of the orbit to the lower edge of the upper wall of the orbit at a uniform interval and slice thickness to obtain continuous T1 mapping images of the extraocular muscles.

[0055] In this embodiment, as Figure 2As shown, adjust the appropriate window width and window level and apply false color to clearly display the T1 mapping images of the extraocular muscles at each axial plane, and manually delineate the regions of interest (ROIs) of the extraocular muscles; based on the boundaries of the initial ROIs, adopt a manual adjustment method of slicing layer by layer to accurately track the signal intensity difference interface between the extraocular muscles and the surrounding adipose tissue, adjust the boundaries of the ROIs of the extraocular muscles before and after enhancement, and confirm the positional consistency of the ROIs after correction; finally, form the ROIs of each extraocular muscle that meet the requirements for T1 value calculation. Similarly, obtain the blood ROIs of the C6-7 segments of the internal carotid artery.

[0056] Substitute the obtained T1 values and hematocrit of the extraocular muscles and the blood of the C6-7 segments into the extracellular volume calculation formula to calculate the extracellular volume of the extraocular muscles. The extracellular volume calculation formula for the extraocular muscles is:

[0057]

[0058] where MRI = magnetic resonance imaging;

[0059]

[0060] represents the longitudinal relaxation rate;

[0061] EOM = extraocular muscle;

[0062] Hct = hematocrit;

[0063] T1 post = the T1 value measured when the tissue reaches a steady state 10 minutes after injecting the gadolinium contrast agent;

[0064] T1pro = the T1 value measured before injecting the gadolinium contrast agent.

[0065] Establish a mapping relationship between the T1 mapping image data module and the pixel index through the spatial coordinate system (DICOM Tag 0020,0032) in the DICOM tag, and store the correlation matrix of the three-dimensional spatial coordinates and the T1 and ECV values using an octree data structure to support seamless docking with the 3D Slicer medical imaging platform. Use the 3D Slicer medical imaging software to generate a pseudo-color three-dimensional model based on the ECV value gradient, and at the same time provide multi-planar reformation (MPR) views in the axial, coronal, and sagittal planes.

[0066] The above specific embodiments are only explanations of the present invention, and they are not limitations of the present invention. Those skilled in the art can make modifications to the embodiments without creative contributions according to needs after reading this specification, but as long as they are within the scope of the claims of the present invention, they are protected by the patent law.

Claims

1. An extraocular muscle extracellular volume measurement system based on magnetic resonance imaging, characterized in that Including: Data acquisition module: performing magnetic resonance imaging (MRI) scans on the extraocular muscle cells of a patient to obtain MRI data of the extraocular muscle cells; Image preprocessing module: calculating the T1 value and quantifying the extracellular volume (ECV) of the MRI data of the extraocular muscle cells to obtain preprocessed data; Data export module: associating the T1 value and ECV data of the two-dimensional region of interest (ROI) with the three-dimensional spatial coordinates in the DICOM file, and exporting the associated data to medical image processing software; Three-dimensional modeling module: reconstructing a three-dimensional model of the associated data using 3D Slicer medical image processing software.

2. The extracellular volume measurement system and method for extraocular muscle cells based on magnetic resonance imaging according to claim 1, characterized in that: Taking the line connecting the external auditory meatus and the ipsilateral lateral canthus of the eye as the horizontal line of the orbit, making a plane cut parallel to this horizontal line, and cutting from the upper edge of the inferior orbital wall to the lower edge of the superior orbital wall at a uniform interval and slice thickness to obtain continuous T1 mapping images of the extraocular muscle, and exporting the images in a fixed format as the medical image data.

3. The extracellular volume measurement system and method of extraocular muscle cells based on magnetic resonance imaging according to claim 1, characterized in that: Adjusting the appropriate window width and window level and adding false colors to clearly display the T1 mapping images of the extraocular muscle in each axial plane, manually delineating the ROI of the extraocular muscle; based on the boundary of the initial ROI, using a layer-by-layer slicing and manual adjustment method to accurately track the signal intensity difference interface between the extraocular muscle and the surrounding adipose tissue, adjusting the boundary of the ROI of the extraocular muscle before and after enhancement, and confirming the position consistency of the ROI after correction; finally forming the ROI of each extraocular muscle that meets the requirements for T1 value calculation; similarly, obtaining the ROI of the blood in the C6-7 segment of the internal carotid artery.

4. A system and method for measuring the extracellular volume of extraocular muscle cells based on magnetic resonance imaging according to claim 1, characterized in that: Collecting 2 mL of peripheral blood from the patient's cubital vein, storing it using a blood collection tube containing an anticoagulant to prevent blood coagulation from affecting the detection accuracy; centrifuging the collected blood sample in a centrifuge at a speed of 3000 rpm for 10 minutes; Reading the hematocrit through a fully automatic blood analyzer.

5. The extracellular volume measurement system and method for extraocular muscle cells based on magnetic resonance imaging according to claim 1, characterized in that: The data export module establishes a mapping relationship between the spatial coordinate system and the pixel index in the DICOM tag, stores the association matrix of the three-dimensional spatial coordinates and the T1 and ECV values using an octree data structure, and supports seamless docking with the 3D Slicer medical imaging platform.

6. The extracellular volume measurement system and method of extraocular muscle cells based on magnetic resonance imaging according to claim 1, characterized in that: Using 3D Slicer medical imaging software to generate a pseudo-color three-dimensional model based on the ECV value gradient, and at the same time providing multi-planar reformation views in the axial, coronal, and sagittal planes.

7. A method for measuring the extracellular volume of extraocular muscle cells based on magnetic resonance imaging, characterized in that, Including the following steps: Step S1: Performing a T1 mapping plain scan to obtain the T1 mapping image of the extraocular muscle MRI; Step S2: Performing an enhanced T1 mapping scan 10 minutes after injecting the gadolinium contrast agent to obtain the enhanced T1 mapping image of the extraocular muscle MRI; Step S3: Respectively drawing the T1 mapping ROIs of the 8 extraocular muscles in the plain scan and enhancement, as well as the same C6-7 segment of the internal carotid artery, and recording the corresponding T1 values; Step S4: Substituting all the T1 values and the patient's hematocrit into the formula to calculate the extracellular volume of the extraocular muscle; Step S5: According to the obtained T1 mapping images of the extraocular muscle, using 3D Slicer medical image processing software to reconstruct a three-dimensional model of the associated data and establish a three-dimensional model of the extraocular muscle.

8. A method for measuring the extracellular volume of extraocular muscle cells based on magnetic resonance imaging according to claim 7, characterized in that, The extracellular volume calculation formula for extraocular muscle cells is as follows: where MRI = magnetic resonance imaging; represents the longitudinal relaxation rate; EOM = extraocular muscle; Hct = hematocrit; T1 post = The T1 value measured when the tissue reaches a steady state 10 minutes after injection of gadolinium contrast agent; T1pro = the T1 value measured before injection of gadolinium contrast agent.

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