JP5105823B2 - Magnetic resonance imaging apparatus, medical image processing method, program, and medical image display system - Google Patents

Description

  The present invention relates to a magnetic resonance imaging apparatus, a medical image processing method, a program, and a medical image display system, and in particular, a magnetic resonance imaging apparatus, a medical image processing method, a program, and a medical image for uniformizing the level of image data of a plurality of slices. It relates to a display system.

  An MRI apparatus detects an NMR signal (echo signal) generated in a subject by applying a high-frequency magnetic field pulse to the subject placed in a strong magnetic field space, and performs a Fourier transform on the response signal, thereby generating a living body. Information is imaged as multiple slices.

  However, since the image data captured by the MRI apparatus is imaged by performing Fourier transform on the echo signal in response to the high-frequency magnetic field pulse (RF pulse), the living tissue is similar to the image data captured by the X-ray CT apparatus. It does not become the value decided every time. Therefore, when a plurality of images are displayed side by side, it may be difficult to compare the plurality of images because the brightness or the like of the displayed images is not constant.

In order to cope with this, Patent Document 1 discloses an objective comparison between images by sequentially switching and displaying the anatomical position and brightness between a plurality of images including the same part. An easy technique is disclosed.
JP 2006-95279 A

  However, Patent Document 1 has the following drawbacks. In Patent Document 1, it is assumed that processing is performed on different images including the same part, which are taken by the same device, that is, the same slice taken at different times by the same device.

  When imaging is performed with an MRI apparatus, biological information is usually imaged as a plurality of slices. In this case, for each arbitrary slice, slices are sequentially measured according to a set pulse sequence (irradiated applied pulse).

  When measuring biological information of a predetermined slice and then measuring biological information of a slice adjacent to the predetermined slice, the state excited by the pulse sequence in the biological body of the previously measured slice is the state before excitation You may not be able to return to

  Such residual information of the slice affects the distribution state of the image data of the slice. That is, the influence of the residual information of the slice may appear as a state where an appropriate offset value is added to the entire image data of the adjacent slice.

  When such a slice is image-displayed with the same window / level value set, a place (same target) that is assumed to be in the same state and in the same living tissue is displayed with different brightness for each slice. Etc., which affect the reconstructed image.

  For the reasons described above, in the method described in Patent Document 1, in order to display the whole of a plurality of slices (series) acquired by one photographing with the same brightness, the operator needs to display the window / level. An adjustment operation needs to be performed. In other words, the method described in Patent Document 1 solves the object of facilitating comparison of a plurality of slices while maintaining the brightness of the displayed image constant when displaying a plurality of slices of the entire series side by side. It is not possible.

  In addition, since the slice positions of the plurality of slices are different, even if the brightness of the entire slice is simply fixed, the same object included in the slices of the entire series cannot be displayed with the same brightness.

  The present invention has been made in view of the above circumstances, and by making the level of image data of the same object of a plurality of slices uniform, the same object of a plurality of slices can be made the same without performing window / level adjustment. It is an object of the present invention to provide a magnetic resonance imaging apparatus, a medical image processing method, a program, and a medical image display system that can display with brightness.

In order to solve the above problems, a magnetic resonance imaging apparatus of the present invention includes a static magnetic field generating means for generating a static magnetic field, a gradient magnetic field generating means for generating a gradient magnetic field, and a predetermined pulse sequence for applying a high-frequency magnetic field pulse to a subject. A high-frequency transmission unit that repeatedly irradiates the light, a high-frequency reception unit that detects a magnetic resonance signal from the subject, and a plurality of slices of the subject by performing image reconstruction calculation using the magnetic resonance signal detected by the high-frequency reception unit an image reconstruction means for acquiring image data of a magnetic resonance imaging apparatus and an output means for outputting the image data of said plurality of slices to the display means for displaying an image based on the image data of said plurality of slices , a region of interest setting means for setting a predetermined region of interest with respect to the image data of said plurality of slices, the plurality of slide Image and the first average value calculating means for calculating an average value of the image data of the set of interest for each region with respect to data, the first average value calculating means and said plurality of based on the calculated average value of Using the correction value calculating means for calculating a correction value for making the level of the image data of the region of interest set for the image data of the slice uniform, and the correction value calculated by the correction value calculating means, Correction means for correcting the image data of each slice so that the levels of the image data of the plurality of slices are uniform.

  According to this magnetic resonance imaging apparatus, a predetermined region of interest is set for a plurality of slices, and an average value of image data for each region of interest is calculated. A correction value for making the level of the image data of the region of interest of the plurality of slices uniform is calculated based on the average value, and the level of the image data of the plurality of slices is made uniform using the correction value. The image data of each slice is corrected. Thereby, the level of the image data of the same object of a plurality of slices can be made uniform.

In a preferred magnetic resonance imaging apparatus of one embodiment, prior Symbol display means displays the one or images on based on a plurality of slice image data, further comprising an instruction means to instruct by a manual operation using any area It is a feature.

  According to this magnetic resonance imaging apparatus, image data of one or a plurality of slices is displayed on the display unit, and the region of interest is set by manually operating the instruction unit on the displayed slice. By manually operating the instruction means, an optimum place for correcting the level of the image data can be set as the region of interest. Therefore, the level of the image data of the same target in a plurality of slices can be surely made uniform.

In the magnetic resonance imaging apparatus of a preferred embodiment, the region of interest setting means includes image area extraction means for extracting an image area of a subject from the image data of the plurality of slices , and image data of the extracted image area Dividing means for dividing the image data into a plurality of blocks, second average value calculating means for calculating an average value of the image data for each block divided by the dividing means for each of the image data of the plurality of slices , and the division each block divided by means of the same block in the image data of said plurality of slices, a dispersion calculating means for calculating the variance of the average second average value calculating means is calculated, the variance calculating means Block detecting means for detecting a block having the smallest variance calculated in step (b), and detecting a block detected by the block detecting means. It is characterized by setting the frequency as the region of interest.

  According to this magnetic resonance imaging apparatus, an image area of a subject is extracted from a plurality of slices, and image data of the extracted image area is divided into a plurality of blocks. An average value of image data for each block is calculated, and a block having a minimum variance of the average value is extracted as a region of interest. By automatically correcting the level of the image data, an optimal location can be set as the region of interest.

The medical image processing method of the present invention includes a step of acquiring image data of a plurality of slices of a subject imaged by a medical image imaging apparatus, and setting a predetermined region of interest for the image data of the plurality of slices Calculating the average value of the image data for each region of interest set for the image data of a plurality of slices in the step of setting the predetermined region of interest, and the average of the image data for each region of interest Calculating a correction value for uniformizing the level of the image data of the region of interest set for the image data of the plurality of slices based on the average value calculated in the step of calculating the value; of the correction value calculated in the step of calculating a correction value for a uniform level of the image data of the set region of interest with respect to the image data of the slice There are, is characterized by comprising the steps of levels of image data of said plurality of slices to correct the image data for each slice to be uniform.
The program of the present invention includes a step of obtaining image data of a plurality of slices of a subject imaged by a medical image photographing apparatus, and a step of setting a predetermined region of interest for the image data of the plurality of slices. Calculating an average value of image data for each region of interest set for the image data of a plurality of slices in the step of setting the predetermined region of interest; and calculating an average value of the image data for each region of interest Calculating a correction value for equalizing the level of the image data of the region of interest set for the image data of the plurality of slices based on the average value calculated in the step of Using the correction value calculated in the step of calculating the correction value for making the level of the image data of the region of interest set for the image data uniform Characterized in that to execute the steps of the level of the image data of said plurality of slices to correct the image data for each slice to be uniform, to the computing device.
The medical image display system according to the present invention acquires a medical image capturing apparatus that acquires image data of a plurality of slices of a subject, and image data of a plurality of slices of the subject that are captured by the medical image capturing apparatus. An image for each region of interest set for the image data of a plurality of slices in the step, a step of setting a predetermined region of interest for the image data of the plurality of slices, and a step of setting the predetermined region of interest An image of the region of interest set for the image data of the plurality of slices based on the average value calculated in the step of calculating the average value of the data and the step of calculating the average value of the image data for each region of interest A step of calculating a correction value for making the data level uniform, and an image data of the region of interest set for the image data of the plurality of slices. Correcting the image data of each slice so that the level of the image data of the plurality of slices is uniform using the correction value calculated in the step of calculating the correction value for making the level of the data uniform. , A medical image processing apparatus comprising a storage device that stores a program for executing the above, a computing device that reads and executes the program from the storage device, and a plurality of subjects output from the medical image processing device And a display device for displaying the image .

  According to the present invention, it is possible to display the same object of a plurality of slices with the same brightness without performing window / level adjustment by making the level of the image data of the same object of the plurality of slices uniform.

  The best mode for carrying out the present invention will be described below with reference to the accompanying drawings.

<First Embodiment>
The present invention manually sets a region of interest for a plurality of slices photographed by a magnetic resonance imaging apparatus (MRI apparatus), which is one of medical image apparatuses, so that image data of the same target in a plurality of slices can be obtained. The level can be made uniform, and the same object in a plurality of slices can be displayed with the same brightness without performing window / level adjustment.

  FIG. 1 is a schematic diagram showing a configuration of a medical imaging apparatus 10 according to the first embodiment of the present invention. This medical imaging apparatus 10 uses the NMR phenomenon to measure the nuclear spin density distribution, relaxation time distribution, and the like at a desired examination site in the subject, and acquires image data of an arbitrary cross section of the subject from the measurement. The magnetic resonance imaging apparatus (MRI apparatus) displays an image of an arbitrary cross section of the subject by reconstructing image data.

  The MRI apparatus 10 mainly includes a static magnetic field coil 101 that applies a static magnetic field to a subject, a gradient magnetic field coil 102 that applies a gradient magnetic field to the subject, a gradient magnetic field power source 103 that supplies power to the gradient magnetic field coil 102, and a subject. An irradiation coil 104 that repeatedly applies an RF pulse that causes an NMR phenomenon to atomic nuclei that constitute an ecological tissue in a predetermined pulse sequence, and a transmission system 105 that irradiates the subject with the RF pulse by the RF pulse from the irradiation coil A receiving coil 106 that detects an echo signal emitted by the NMR phenomenon, a receiving system 107 that detects an echo signal received by the receiving coil 106, and an image reconstruction operation using the echo signal detected by the receiving system. CPU 108 for performing processing such as control and control of each part of the MRI apparatus, and display means for displaying an image (display A) 109, a console 110 for inputting an instruction to each part of the MRI apparatus, a storage device 111 for storing data, an examination table 116 for arranging the subject 112 in the imaging space, and a projection position of the subject 112 A projection position control device 113 for controlling, an inspection table position determination device 114 for detecting the position of the inspection table 116, and an external image output device 117 for outputting the image data of the slice reconstructed by the CPU 108 to an external display device. ing.

  The static magnetic field coil 101 is provided with a plurality of static magnetic field generating magnets sandwiching an imaging space, and generates a uniform static magnetic field in the imaging space in the body axis direction of the subject 112 or in a direction perpendicular to the body axis. As a magnetic field generation method of the static magnetic field generating magnet, a permanent magnet method, a normal conduction method, or a superconductivity method can be used.

  The gradient magnetic field coil 102 is driven in accordance with a command from the sequencer, and applies an orthogonal three-axis gradient magnetic field to the subject 112 to give positional information to the echo signal. By changing how the gradient magnetic field is applied, for example, an arbitrary imaging section can be set on the subject 112.

  The transmission system 105 irradiates an RF pulse that causes nuclear magnetic resonance to the atomic nuclei constituting the biological tissue of the subject 112, and passes through an irradiation coil 104 disposed in the vicinity of the subject 112. The object 112 is irradiated with an RF pulse.

  The reception system 107 detects a magnetic resonance signal (NMR signal, that is, an echo signal), which is obtained through nuclear magnetic resonance of nuclear spins constituting the biological tissue of the subject 112, acquired via the reception coil 106.

  The CPU 108 performs processing such as Fourier transform, correction coefficient calculation, image reconstruction, etc. on the echo signal detected by the receiving system 107, and performs an appropriate calculation on the signal intensity distribution of the arbitrary cross section or a plurality of signals. The level and distribution of the image data of the obtained slice are imaged. In addition, the CPU 108 stores the obtained slice image data in the storage device 111.

  Note that the image display method, registration in the database, and the like are techniques already performed by a conventional MRI apparatus and generally using software and hardware, and thus description thereof is omitted in this embodiment.

  In the image data of the slice 12 (see FIG. 2) obtained in this way, the state in which the hydrogen atoms in the body of the subject 116 are excited in the pulse sequence cannot return to the state before the excitation. An appropriate offset value may be added to the entire image data.

  When an offset value is added to the image data of a slice (see FIG. 3B), as shown in FIG. 3A, a predetermined slice and an adjacent slice are displayed even if they are the same target. The brightness will change. Therefore, the offset value is removed by the following method, and as shown in FIG. 3C, the levels of the same target image data in a plurality of slices are made uniform.

  Next, a method of removing the offset value added to the slice image data will be described.

  FIG. 4 is a flowchart showing a flow of processing for removing the offset value added to the image data of the slice. The CPU 108 operates according to this flowchart. The following processing is started after the CPU 108 acquires image data of the slice of the subject 116 and performs image reconstruction.

  First, a plurality of reconstructed slices are displayed on the display 109 (step S10). For example, a plurality of slices (series) acquired by one photographing are arranged and displayed on the display 109.

  Next, when correcting the image data of the slice, a reference region of interest (ROI) setting process and ROI average value calculation process (steps S12 to S20) are performed.

  i = 1 is set (step S12). That is, processing is started from the first slice.

  On a predetermined slice, a place (same target) that is assumed to be the same living tissue and the same state in the entire series is set as the ROI (step S14). When the offset value is not added to the image data of the slice, the same living tissue and the same state, that is, the image data of the same target is considered to be the same. The place to be set is set as the ROI.

  The ROI is set by manually operating a pointing device such as a mouse on the slice displayed on the display 109 by the operator and inputting an instruction to the CPU 108. Then, the ROI is set for all the slices in the series by applying the selected portion to a predetermined slice to all the slices. For example, as shown in FIG. 2, when the ROI 14 is set at the lower right side near the center of a predetermined slice 12, the ROI is set at the lower right side near the center in the slices of the entire series.

  Then, the average value (S-ROImean (i)) of the image data in the ROI set in step S24 is calculated (step S16). Although the place assumed to be the same target is set as the ROI, since the ROI includes a plurality of pixels, there is a difference in image data even within the ROI. Therefore, a process for calculating the average of the image data in the ROI is performed.

  i = i + 1 is set (step S18), and it is determined whether i = N, that is, whether all slices have been processed (step S20).

  If i is not N (NO in step S20), ROI setting processing (step S14) is performed again.

  If i = N (YES in step S20), the reference region of interest (ROI) setting process and the average value calculation process for each ROI are terminated.

  When the reference region of interest (ROI) setting processing and ROI average value calculation processing are completed, slice image data correction processing (steps S22 to S32) is performed.

An average value ( S- Ser-ROImean) of the entire ROI series is calculated (step S22).

  i = 1 is set (step S24). That is, processing is started from the first slice.

The average value of the image data of the calculated slices within another ROI in step S16 (S-ROImean (i) ) and the average value of the entire series of the image data of the calculated the ROI in step S22 (S -Ser-ROImean ) (See Equation 1), the correction value (S-COMP (i)) of the image data of the slice is calculated (step S26).

[Equation 1]
S-COMP (i)
= S-ROImean (i) -S-Ser-ROImean
Then, by adding the correction value (S-COMP (i)) of the image data of the slice calculated in step S26 to the image data of the slice (S-Image (i)) (see Equation 2), The image data is corrected (step S28).

[Equation 2]
S-COMP-Image (i)
= S-Image (i) + S-COMP (i)
i = i + 1 is set (step S30), and it is determined whether i = N, that is, whether all slices have been processed (step S32).

  If i = N is not satisfied (NO in step S30), the correction value (S-COMP (i)) calculation process (step S26) of the image data of the slice is performed again.

  If i = N (YES in step S30), the slice image data correction process ends.

  As described above, when the offset value is not added to the image data of the slice, the image data in the ROI of each slice is the same, so the average value of the image data in the ROI for each slice (S-ROImean ( i)) and the correction value (S-COMP (i)) of the image data of the slice calculated from the difference between the average value (S-Ser-ROImean) of the entire series of image data in the ROI. By correcting the image data, the brightness of the same object in a plurality of slices becomes constant.

  Finally, the corrected slice image data (S-COMP-Image (i)) is stored in the storage device 111 (step S34).

  Thereby, the offset value added to the image data of the slice is removed, and the level of the image data of the slice of the entire series is made uniform.

  The corrected slice image data (S-COMP-Image (i)) stored in the storage device 111 is read and output to the display 109, so that a slice in which the same target is displayed with the same brightness is displayed on the display 109. Is displayed.

  Further, the read image data of the corrected slice (S-COMP-Image (i)) is output to an external display device via the external image output device 117, so that the type of display device and the setting method are displayed. Slices in which the same object is displayed with the same brightness can be displayed.

  According to the present embodiment, since a predetermined region of interest is set and the image data of a plurality of slices is corrected based on the image data of the region of interest, the level of the image data of the same target in the plurality of slices is made uniform. Can be.

  Further, according to the present embodiment, the optimum place for correcting the level of the image data is set as the region of interest by manually operating the instruction means. The level of the image data of the slices can be made uniform.

  In addition, according to the present embodiment, the level of image data of the same target in a plurality of slices is uniform, so that slices in which the same target is displayed with the same brightness regardless of the type of the display device, the setting method, etc. Can be displayed.

  In this embodiment, the slices of the entire series are displayed side by side on the display 109. However, the display method is not limited to this, and only the selected slices may be displayed. You may make it display by switching in order.

  In this embodiment, the place where the living tissue is assumed to be substantially the same on a predetermined slice is set as the ROI. However, the place assumed to be the same target is selected for each slice in the entire series. The ROI may be set, or the ROI set on the desired slice is applied to the slices of the entire series, and then the ROI is set or corrected for each slice as necessary. Also good.

  In this embodiment, the processing is terminated after the image data (S-COMP-Image (i)) of the corrected slice is stored in the storage device 111, but the corrected slice is displayed. A means for confirming whether the level of the image data of the same target in the entire slice is uniform is provided. When the level of the image data in the slice of the entire series is uniform, the processing is terminated, and If the level of the image data of the slice is not uniform, the processing may be performed again from the ROI setting. This makes it more reliable to make the level of the image data of the slices of the entire series uniform when compared with the same target.

<Second Embodiment>
In the medical image device according to the first embodiment, a region of interest is manually set for a plurality of slices, and the image data of the same target of the plurality of slices is corrected based on the image data of the region of interest. Thus, the level of the same target image data in a plurality of slices is made uniform, but the method of making the level of the same target image data in a plurality of slices uniform is not limited to this.

  The medical imaging apparatus (magnetic resonance imaging apparatus) according to the present embodiment automatically sets an optimum location as a region of interest for automatically correcting the level of image data, and uses a plurality of image data of the region of interest as a reference. By correcting the image data of the same target of the slice, the level of the image data of the same target of the plurality of slices is made uniform. In the figure, the same portions as those of the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

  A method for automatically removing the offset value added to the image data of the slice will be described.

  FIG. 5 is a flowchart showing a flow of processing for removing the offset value added to the image data of the slice according to the second embodiment of the present invention. The CPU 108 operates according to this flowchart. The following processing is started after the CPU 108 acquires the image data of the slice of the subject 116 and performs image reconstruction and storage in the database.

  An image region 16 (see FIG. 6A) in which an image of the subject is captured is extracted from the slice (step S40). Note that the image region 16 of the smallest slice among the slices of the entire series is applied as the image region 16 of the slices of the entire series.

  i = 1 is set (step S42). That is, processing is started from the first slice.

  The image area 16 extracted in step S42 is divided into a plurality of n × n blocks (step S44). Note that the number of blocks to be divided (the number of divisions) is set in advance according to the imaged part, and when the imaged part is input, division is automatically performed with the set number of divisions. FIG. 6B shows an example in which the image area 16 shown in FIG. 6A is divided into 4 × 4 blocks. In the following, the block arranged at the upper left is B (1,1), the block to the right is B (1,2), the leftmost block in the second column is B (2,1), etc. The position of the block is expressed as B (x, y).

  For each block B (x, y), the average value (S-BLOCK mean (x, y, i)) of the image data in the block is calculated (step S44). For example, in FIG. 7, the average value of the image data in the block B (1, 2) of the slice 1 is S-BLOCK mean (1, 2, 1).

  i = i + 1 is set (step S48), and it is determined whether i = N, that is, whether all slices have been processed (step S50).

  If i = N is not satisfied (NO in step S50), a step (step S44) of dividing the image region into a plurality of n × n blocks is performed again.

When i = N (YES in step S50), the variance (σ-BLOCK (x) of the average value of the image data of the block B (x, y) calculated for the slices of the entire series is calculated. , Y)) is calculated (step S5 2 ). For example, in FIG. 7, the variance of the average value (S-BLOCK mean (1, 2, i)) (i: 1 to N) of the image data in the block B (1, 2) of slices 1 to N is σ-BLOCK. (1, 2), and this processing is performed for all the blocks B (x, y).

Variance calculated in step S5 2 (σ-BLOCK (x , y)) is a block which is a minimum, the living tissue is detected as the location (region of interest) which is assumed to be approximately the same state (step S54) . In the following description, it is assumed that the variance of the block B (j, k) is minimized.

  Next, the average value (S-BLOCK mean (j, k, i)) (i: 1) of the image data in the block B (j, k) having the smallest variance (σ-BLOCK (x, y)). ˜N), an average value (S-Ser-BLOCK mean (j, k)) for the entire series is calculated (step S56).

  i = 1 is set (step S58). That is, processing is started from the first slice.

  The average value (S-BLOCK mean (j, k, i)) of the block B (j, k) with the smallest variance and the average value (S for the entire series of the block B (j, k) with the smallest variance. By taking a difference from -Ser-BLOCKmean (j, k)) (see Equation 3), a correction value (S-BLOCK-COMP (i)) of the image data of the slice is calculated (step S60).

[Equation 3]
S-BLOCK-COMP (i)
= S-BLOCK mean (j, k, i)
-S-Ser-BLOCK mean (j, k)
Then, by adding the correction value (S-BLOCK-COMP (i)) of the slice image data calculated in step S60 to the slice image data (S-Image (i)) (see Equation 4), The image data of the slice is corrected (step S62).

[Equation 4]
S-COMP-Image (i)
= S-Image (i) + S-BLOCK-COMP (i)
i = i + 1 is set (step S64), and it is determined whether i = N, that is, whether all slices have been processed (step S66).

  If i = N is not satisfied (NO in step S30), the correction value (S-BLOCK-COMP (i)) calculation process (step S60) of the image data of the slice is performed again.

    If i = N (YES in step S30), the corrected slice image data (S-COMP-Image (i)) is stored in the storage device 111 (step S68).

  According to the present embodiment, since the optimum location for automatically correcting the level of image data is set as the region of interest, it is easy to make the level of the same target image data in a plurality of slices uniform. Become.

  In the present embodiment, the extracted image region is divided into 4 × 4 blocks. However, the number of divided image regions is not limited to 4 × 4 as long as it is n × n blocks.

  In the present embodiment, when a photographed part is input, the division is automatically performed with the set number of divisions, but the division method is not limited to this. For example, the number of divisions may be input every time image data of a slice is corrected.

  Alternatively, the above processing may be performed with a plurality of division numbers, and the division number with the smallest correction value for each slice may be automatically determined as the normal division number. For example, when it is initially set to be divided by 4 × 4, processing is performed with five division numbers of 2 × 2, 3 × 3... 6 × 6, and processing is performed with 4 × 4 division numbers. If the correction value of each slice becomes the smallest when it is performed, the image data of each slice may be corrected using the correction value of each slice obtained by the number of divisions of 4 × 4. .

  In the above-described embodiment, the magnetic resonance imaging apparatus (MRI apparatus) has been described as an example. However, the present invention is not limited to this. In an image processing apparatus to which a medical image captured by an MRI apparatus, an X-ray apparatus, or the like is input, By correcting so that the level of the image data of the same target in a plurality of slices becomes uniform, and outputting the image data of the corrected slice to the image display device, the same target of the plurality of slices has the same brightness. It may be displayed.

1 is a schematic diagram illustrating an overall configuration of a first embodiment of a medical imaging apparatus to which the present invention is applied. It is a schematic diagram of the slice image | photographed with the said medical imaging device. It is explanatory drawing explaining the method of equalizing the image data of the slice of 1st Embodiment of the said medical imaging device, (a) shows ROI before equalizing the image data of a slice, (b) Shows the state of the ROI image data before making the image data of the slice uniform, and (c) shows the state of the ROI image data after making the image data of the slice uniform. It is a flowchart which shows the flow of a process of 1st Embodiment of the said medical imaging device. It is a flowchart which shows the flow of a process of 2nd Embodiment of the medical imaging device to which this invention was applied. It is explanatory drawing explaining the method to divide | segment the image area of 2nd Embodiment of the said medical imaging device into several blocks, (a) shows an image area, (b) was divided | segmented into the several block Indicates the state. It is explanatory drawing explaining the method of equalizing the image data of the slice of 2nd Embodiment of the said medical imaging device.

Explanation of symbols

10: Medical imaging device (magnetic resonance imaging device), 12: slice, 15: region of interest (ROI), 16: image region

Claims (9)

A static magnetic field generating means for generating a static magnetic field, a gradient magnetic field generating means for generating a gradient magnetic field, a high frequency transmitting means for repeatedly irradiating a subject with a high frequency magnetic field pulse in a predetermined pulse sequence, and a magnetic resonance signal from the subject High-frequency receiving means for detecting, image reconstructing means for performing image reconstruction calculation using the magnetic resonance signal detected by the high-frequency receiving means and acquiring image data of a plurality of slices of the subject,
An output means for outputting the image data of the plurality of slices to a display means for displaying an image based on the image data of the plurality of slices;
The image data of each slice included in the plurality of slices, and region of interest setting means for setting a predetermined region of interest,
For each of the previous SL region of interest set on the image data of each slice, and average value calculating means that to calculate the average value of the image data of each region of interest,
The mean value of the region of interest of each slice issued before hexane, calculates an average value over between the plurality of slices, for each of the slices, said plurality of slices and the average value of the set region of interest on the slice A correction value calculating means for calculating a difference with an average value between them and calculating a correction value for each slice ;
The correction value of each slice issued before hexane by adding the image data of the slice, and a correction means for the level of the image data of said plurality of slices to correct the image data for each slice to form a uniform ,
A magnetic resonance imaging apparatus comprising:   2. The region-of-interest setting unit includes an instruction unit that manually instructs an arbitrary region on an image based on image data of one or a plurality of slices displayed on the display unit. The magnetic resonance imaging apparatus described in 1. A static magnetic field generating means for generating a static magnetic field, a gradient magnetic field generating means for generating a gradient magnetic field, a high frequency transmitting means for repeatedly irradiating a subject with a high frequency magnetic field pulse in a predetermined pulse sequence, and a magnetic resonance signal from the subject High-frequency receiving means for detecting, image reconstructing means for performing image reconstruction calculation using the magnetic resonance signal detected by the high-frequency receiving means to obtain image data of a plurality of slices of the object, and In a magnetic resonance imaging apparatus comprising: output means for outputting image data of the plurality of slices to display means for displaying an image based on image data;
A region of interest setting means for setting a predetermined region of interest for the image data of the plurality of slices;
First average value calculating means for calculating an average value of image data for each region of interest set for the image data of the plurality of slices;
A correction value for calculating a correction value for equalizing the level of the image data of the region of interest set for the image data of the plurality of slices based on the average value calculated by the first average value calculation means A calculation means;
Correction means for correcting the image data of each slice so that the level of the image data of the plurality of slices is uniform using the correction value calculated by the correction value calculation means,
The region of interest setting means includes
Image area extracting means for extracting the image area of the subject from the image data of the plurality of slices, dividing means for dividing the image data of the extracted image area into a plurality of blocks, and for each of the image data of the plurality of slices A second average value calculating means for calculating an average value of the image data for each block divided by the dividing means, and the same block in the image data of the plurality of slices for each block divided by the dividing means A variance calculating means for calculating the variance of the average value calculated by the second average value calculating means, and a block detecting means for detecting a block having the minimum variance calculated by the variance calculating means. , Setting a block area detected by the block detection means as the region of interest;
A magnetic resonance imaging apparatus. Acquiring image data of a plurality of slices of a subject imaged by a medical imaging apparatus;
A step of the image data for each slice, a predetermined area of interest included in the plurality of slices,
Calculating said each of the related heart area set for the image data of each slice, the mean value of the image data for each interest area,
Before hexane issued an average value for each ROI of each slice was the average value calculated over between a plurality of slices, for each of the slice, the mean value of the set region of interest on the slice and the plurality of Calculating a difference with an average value between slices, and calculating a correction value for each slice ;
The correction value of each slice issued before hexane, and correcting by adding to the image data of the slice, the image data of each slice so that the level of the image data of said plurality of slices become uniform,
A medical image processing method comprising: Acquiring image data of a plurality of slices of a subject imaged by a medical imaging apparatus;
Setting a predetermined region of interest for the image data of the plurality of slices;
Calculating an average value of the image data before Ki設 constant has been of interest for each region,
Calculating a correction value for the level of the image data of the set region of interest with respect to the image data of the plurality of slices based on the previous hexane issued average value uniformly,
Using front hexane issued correction value comprises the steps of levels of image data of said plurality of slices to correct the image data for each slice to be uniform,
The step of setting the region of interest extracts the image area of the subject from the image data of the plurality of slices, divides the image data of the extracted image area into a plurality of blocks, and sets the image data of the plurality of slices. The average value of the image data for each of the divided blocks is calculated, and the variance of the average value of the image data for the same block in the image data of the plurality of slices is calculated for each of the divided blocks, A region of a block having the smallest variance is set as the region of interest.
A medical image processing method characterized by the above. Acquiring image data of a plurality of slices of a subject imaged by a medical imaging apparatus;
Setting a predetermined region of interest for image data of each slice included in the plurality of slices;
Calculating an average value of the image data of each region of interest for each region of interest set for the image data of each slice;
The average value for each region of interest of each calculated slice is calculated across the plurality of slices, and for each slice, the average value of the region of interest set in the slice and between the plurality of slices Calculating a difference with an average value over the range, and calculating a correction value for each slice;
Correcting the image data of each slice so that the level of the image data of the plurality of slices is uniform by adding the calculated correction value for each slice to the image data of the slice;
A program that causes an arithmetic device to execute. Acquiring image data of a plurality of slices of a subject imaged by a medical imaging apparatus;
Setting a predetermined region of interest for the image data of the plurality of slices;
Calculating an average value of the image data for each of the set regions of interest;
Calculating a correction value for making the level of the image data of the region of interest set for the image data of the plurality of slices based on the calculated average value;
Correcting the image data of each slice so that the level of the image data of the plurality of slices is uniform using the calculated correction value,
The step of setting the region of interest extracts the image area of the subject from the image data of the plurality of slices, divides the image data of the extracted image area into a plurality of blocks, and sets the image data of the plurality of slices. The average value of the image data for each of the divided blocks is calculated, and the variance of the average value of the image data for the same block in the image data of the plurality of slices is calculated for each of the divided blocks, A region of a block having the smallest variance is set as the region of interest.
A program that causes an arithmetic device to execute the above. A medical imaging apparatus for acquiring image data of a plurality of slices of a subject;
Acquiring image data of a plurality of slices of a subject imaged by the medical image imaging device; setting a predetermined region of interest for image data of each slice included in the plurality of slices; For each region of interest set for the image data of each slice, the step of calculating an average value of the image data of each region of interest, and the plurality of calculated average values for each region of interest of each slice The average value over the slices is calculated, and for each slice, the difference between the average value of the region of interest set in the slice and the average value over the plurality of slices is calculated, and the correction value for each slice Calculating the correction value for each slice, and adding the calculated correction value for each slice to the image data of the slice. A step of correcting the image data of each slice so that the bell is uniform, a storage device that stores a program that causes the arithmetic device to execute, and an arithmetic device that reads and executes the program from the storage device A medical image processing apparatus;
A display device for displaying images of a plurality of subjects output from the medical image processing device;
A medical image display system comprising: A medical imaging apparatus for acquiring image data of a plurality of slices of a subject;
Acquiring image data of a plurality of slices of a subject imaged by the medical imaging apparatus, setting a predetermined region of interest for the image data of the plurality of slices, and the set region of interest A step of calculating an average value of each image data, and a correction value for equalizing the level of the image data of the region of interest set for the image data of the plurality of slices based on the calculated average value And correcting the image data of each slice so that the level of the image data of the plurality of slices is uniform using the calculated correction value, and setting the region of interest The step of extracting the image area of the subject from the image data of the plurality of slices and dividing the image data of the extracted image area into a plurality of blocks An average value of the image data for each of the divided blocks is calculated for each of the image data of the plurality of slices, and image data for the same block in the image data of the plurality of slices for each of the divided blocks A storage device that stores a program that causes an arithmetic device to execute the calculation of the variance of the average value and set the region of the block having the smallest variance as the region of interest, and reads the program from the storage device. A medical image processing apparatus comprising:
A display device for displaying images of a plurality of subjects output from the medical image processing device;
A medical image display system comprising:

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