JP5053682B2 - Magnetic resonance imaging apparatus, image display apparatus, image display program, and image display system - Google Patents

Description

  The present invention relates to a magnetic resonance imaging apparatus, an image display apparatus, an image display program, and an image display system, and more particularly to a stitching process for joining a plurality of images into a single image.

  Conventionally, in imaging using a magnetic resonance imaging apparatus or an X-ray diagnostic apparatus, when imaging a wide range extending over a plurality of parts of a subject, partial overlap occurred while moving the top plate on which the subject was placed A method is used in which a plurality of images are photographed, and the photographed images are joined and combined into a single image.

  In this way, the process of connecting a plurality of images and combining them into one image is called “stitching process”. In this stitching process, when connecting the images, the important point is how to generate a composite image in which the contrast is not conspicuous by matching the contrast of the image data.

  Therefore, for example, for imaging using an X-ray diagnostic apparatus, a predetermined index value (for example, an average value) is obtained from pixel values of two overlapping images for each overlapping portion that becomes a joint of the captured images. A technique has been proposed in which pixel values of each image are corrected so that the calculated index values coincide with each other, and the respective images are connected (for example, refer to Patent Document 1 or 2).

JP 2004-57506 A JP 2005-296332 A

  By the way, in imaging using a magnetic resonance imaging apparatus, a receiving coil for receiving a magnetic resonance signal is attached to a subject, but when imaging a wide range, a plurality of receiving coils (surface coils) that differ for each region are used. ) May be used simultaneously, or a phased array coil composed of a plurality of receiving coils may be used.

  However, the sensitivity for receiving the magnetic resonance signal varies depending on the receiving coil, and the dynamic range reconstructed from the magnetic resonance signal also varies. Therefore, even if the index value is calculated from the pixel value of the overlapping portion as in the conventional technique described above, there is a problem that the index value is not calculated based on the same reference, and the image data cannot be smoothly connected. In the X-ray diagnostic apparatus, even when imaging is performed in a plurality of times, this problem does not occur because the detectors that detect X-rays are always the same.

  The present invention has been made to solve the above-described problems caused by the prior art, and can provide a magnetic resonance imaging apparatus and an image that can smoothly connect image data even when the sensitivity of each receiving coil is different. An object is to provide a display device, an image display program, and an image display system.

In order to solve the above-described problems and achieve the object, the present invention provides a method of reconstructing a plurality of pieces of image data partially overlapping from each of magnetic resonance signals detected by a plurality of receiving coils mounted on a subject. An image data storage unit that is a resonance imaging apparatus and stores a plurality of reconstructed image data and information related to a reception coil that detects a magnetic resonance signal that is a basis of each image data, and the image For each piece of image data stored by the data storage means, based on information relating to the receiving coil corresponding to each image data , correction means for correcting the dynamic range of each image data to coincide with each other, and the dynamic means by the correction means for each overlapping portion of each image data range are matched, calculated Shinano a predetermined index value from the pixel values of the pixels included in the overlaid portion , Based on the image data positioned at the center when ordered the plurality of image data in the body axis direction, to match the index value of the image data, the image data located on both sides of the image data And image combining means for combining the respective image data in the body axis direction and combining them into a single image.

The present invention also provides an image display device for displaying a plurality of partially overlapping image data reconstructed from magnetic resonance signals detected by a plurality of receiving coils mounted on a subject, Image data storage means for associating and storing the plurality of image data thus obtained and information relating to the receiving coil that has detected the magnetic resonance signal that is the basis of each image data, and image data stored by the image data storage means A correction unit that performs correction to match the dynamic range of each image data based on information about the receiving coil corresponding to each image data, and an overlap of each image data that has the same dynamic range by the correction unit for each portion, while calculating a predetermined index value from the pixel values of the pixels included in the overlaid portion, order the plurality of image data in the body axis direction Based on the image data positioned at the center when arranged in, to match the index value of the image data, after correcting the pixel values of each image data located on both sides of the image data, the image data And image combining means for combining the images in the body axis direction into a single image.

Further, the present invention is an image display program for displaying a plurality of image data reconstructed from magnetic resonance signals detected by a plurality of receiving coils mounted on a subject, the plurality of reconstructed images For each image data stored by the image data storage procedure, the image data storing procedure in which the data and the information related to the receiving coil that detected the magnetic resonance signal that is the basis of each image data are associated and stored in the storage device A correction procedure for performing a correction for matching the dynamic range of each image data based on information relating to the receiving coil corresponding to each image data , and for each overlapping portion of each image data whose dynamic range is matched by the correction procedure in, while calculating a predetermined index value from the pixel values of pixels included in the overlapping portion, the plurality of image data in the body axis direction Based on the image data positioned at the center when arranged in turn, to match the index value of the image data, after correcting the pixel values of each image data located on both sides of the image data, each image An image composition procedure for combining data in a body axis direction and compositing into one image is executed by a computer.

The present invention also relates to an image server device for storing a plurality of partially overlapping image data reconstructed from magnetic resonance signals detected by a plurality of receiving coils mounted on a subject, and an image server device. An image display system comprising an image display device that displays stored image data, wherein the image server device detects a plurality of reconstructed image data and a magnetic resonance signal that is the basis of each image data Image data storage means for storing information related to the reception coil in association with each other, and the image display device relates to the reception coil corresponding to each image data for each image data stored by the image data storage means based on the information, and correcting means for correcting for matching the dynamic range of the image data, the dynamic range by the correction means For each overlapping portion of each image data that matches, while calculating a predetermined index value from the pixel values of pixels included in the overlapping portion, centrally located when ordered the plurality of image data in the body axis direction Using the image data as a reference, the pixel values of the image data located on both sides of the image data are corrected so as to match the index value of the image data, and then the image data are connected in the body axis direction to be combined. And image synthesizing means for synthesizing the images.

According to the present invention, there is an effect that image data can be smoothly connected even when the sensitivity of the receiving coils is different.

  Exemplary embodiments of a magnetic resonance imaging apparatus, an image display apparatus, an image display program, and an image display system according to the present invention will be described below in detail with reference to the accompanying drawings. Hereinafter, the magnetic resonance imaging apparatus is referred to as an “MRI apparatus”, and the magnetic resonance signal is referred to as an “MR signal”.

  The MRI apparatus according to the present embodiment reconstructs a plurality of partially overlapping image data from MR signals detected by a plurality of receiving coils mounted on a subject.

  The MRI apparatus according to the present embodiment aims to smoothly connect the image data even when the sensitivity of the receiving coils for receiving the MR signals is different.

  For this reason, this MRI apparatus first stores a plurality of reconstructed image data in association with information related to the receiving coil that has detected the magnetic resonance signal that is the basis of each image data, and stores each stored image data. In addition, after correcting the dynamic range of each image data to a predetermined reference value based on the information related to the receiving coil corresponding to each image data, the overlapping portion for each overlapping portion of each image data whose dynamic range is corrected Calculate a predetermined index value from the pixel values of the pixels included in the image, correct the pixel value of each image data so that the calculated index values match, and then connect each image data in the body axis direction to make one sheet It is characterized by synthesizing the image. Hereinafter, this feature will be specifically described.

  First, the configuration of the MRI apparatus according to the present embodiment will be described. FIG. 1 is a functional block diagram illustrating the configuration of the MRI apparatus according to the present embodiment. As shown in the figure, this MRI apparatus includes a static magnetic field magnet 1, a gradient magnetic field coil 2, an RF coil 3, a static magnetic field power supply 4, a gradient magnetic field power supply 5, a transmitter 6, and a receiver 7. The sequence control device 8 and the computer 100 are configured.

The static magnetic field magnet 1 is a magnet formed in a cylindrical shape, and generates a static magnetic field H ₀ in the space inside the cylinder where the subject P is arranged by the current supplied from the static magnetic field power supply 4. The gradient magnetic field coils 2 are three pairs of coils disposed inside the static magnetic field magnet 1, and three directions of x, y, and z are placed inside the static magnetic field magnet 1 by current supplied from the gradient magnetic field power supply 5. A gradient magnetic field is generated along

  The RF coil 3 is a receiving coil disposed so as to face the subject P within the opening of the static magnetic field magnet 1, and irradiates the subject P with an RF wave transmitted from the transmitter 6, The MR signal emitted from the hydrogen nucleus of the subject P is received by excitation. Here, three RF coils 3 are illustrated, but the RF coils 3 are each mounted with a dedicated shape for each part of the subject P when photographing a wide range.

  The static magnetic field power source 4 is a power source that supplies current to the static magnetic field magnet 1, and the gradient magnetic field power source 5 is a power source that supplies current to the gradient magnetic field coil 2 based on an instruction from the sequence control device 8.

  The transmitter 6 is a device that transmits an RF signal to the RF coil 3 based on an instruction from the sequence control device 8, and the receiver 7 detects the MR signal received by the RF coil 3, and the MR signal. To generate raw data. Note that, when the raw data is generated from the MR signal, the receiver 7 transmits the generated raw data to the sequence control device 8 together with the identification information of the RF coil 3 that has received the MR signal of the raw data.

  The sequence control device 8 is a device that performs imaging of the subject P by driving the gradient magnetic field power source 5, the transmitter 6, and the receiver 7 based on sequence information transmitted from the computer 100. Here, the sequence information refers to the strength of the power supplied from the gradient magnetic field power supply 5 to the gradient magnetic field coil 2 and the timing of supplying the power, the strength of the RF signal transmitted from the transmitter 6 to the RF coil 3, and the RF signal. This is information defining a procedure for performing imaging such as timing and timing at which the receiver 7 detects an MR signal.

  When the raw data is transmitted from the receiver 7 as a result of imaging the subject P, the sequence control device 8 transfers the raw data to the computer 100 together with the identification information of the RF coil 3. .

  The computer 100 controls the MRI apparatus based on an instruction from the operator, converts raw data transmitted from the sequence control apparatus 8 into k-space data, and reconstructs image data from the k-space data. It is.

  Although not shown in FIG. 1, this MRI apparatus has a top plate on which the subject P is placed and a bed that supports the top plate, and moves the top plate along the z direction. Thus, an image of a plurality of parts of the subject P can be taken. The top plate is moved manually or automatically.

  Next, the configuration of software executed by the computer 100 shown in FIG. 1 will be described. FIG. 2 is a functional block diagram showing a configuration of software executed by the computer 100 shown in FIG. As shown in the figure, the software includes an input unit 101, a display unit 102, an image data storage unit 103, a main control unit 104, a sequence control unit 105, and an image reconstruction unit as conceptual functional units. Unit 106, dynamic range correction unit 107, and image composition unit 108.

  The input unit 101 is a means for inputting various types of information. The input unit 101 is realized by a pointing device such as a mouse or a trackball, a keyboard, and the like, and is a user interface for receiving various instructions by cooperating with the display unit 102 described later. Is provided to the operator.

  The display unit 102 is a means for displaying various information, and is realized by a monitor device such as a CRT (Cathode Ray Tube) display or a liquid crystal display.

  The image data storage unit 103 is a storage unit that stores image data reconstructed from k-space data transmitted from the sequence control unit 105. Specifically, the image data storage unit 103 associates a plurality of reconstructed image data with a dynamic range correction coefficient corresponding to the RF coil 3 that detects the MR signal that is the basis of each image data. Remember.

  The “dynamic range correction coefficient” here is a correction coefficient for correcting the dynamic range of the image data to a predetermined reference value, and the RF coil 3 according to the sensitivity of the RF coil 3 that receives the MR signal. It is decided for each.

  The main control unit 104 is a processing unit that controls the MRI apparatus by receiving various instructions from the operator via the input unit 101 and controlling the operation of each functional unit based on the received instructions.

  Specifically, when receiving a shooting instruction from the operator, the main control unit 104 generates sequence information based on the instructed shooting condition and transmits the sequence information to the sequence control unit 105. This sequence information is transmitted to the sequence control device 8 via the sequence control unit 105, and is used when the sequence control device 8 performs photographing.

  Then, when the image reconstruction unit 106 to be described later reconstructs the image data based on the raw data transmitted from the sequence control device 8 after shooting, the main control unit 104 stores the reconstructed image data in the image data The data is read from the unit 103 and displayed on the display unit 102.

  At this time, the main control unit 104 displays image data for each part when a plurality of parts are photographed in one photographing, and operates to designate image data composition and composition target image data. An operation screen to be received from the person is displayed on the display unit 102.

  Thereafter, upon receiving designation of image data to be synthesized from the operator via the operation screen, the main control unit 104 instructs a dynamic range correction unit 107 (to be described later) to correct the dynamic range of the designated image data. The image data whose dynamic range has been corrected by the dynamic range correction unit 107 is displayed on the display unit 102.

  Further, upon receiving an image data synthesis instruction from the operator, the main control unit 104 instructs the image synthesis unit 108 to synthesize the designated image data. At this time, the main control unit 104 also accepts designation of image data serving as a reference for matching the contrast when combining the image data. The designation of the image data serving as the reference may be omitted.

  The sequence control unit 105 is a processing unit that controls transmission / reception of data exchanged with the sequence control device 8. Specifically, when the sequence information is transmitted from the main control unit 104, the sequence control unit 105 transmits the sequence information to the sequence control device 8. When the raw data and the identification information of the RF coil 3 are transmitted from the sequence control device 8, the sequence control unit 105 converts the transmitted raw data into k-space data, and converts the converted k-space data into the RF coil. 3 is transmitted to the image reconstruction unit 106 together with the identification information 3.

  The image reconstruction unit 106 is a processing unit that reconstructs image data by performing a predetermined image reconstruction process on the k-space data transmitted from the sequence control unit 105. Specifically, when k-space data is transmitted from the sequence control unit 105, the image reconstruction unit 106 performs Fourier transform processing or data synthesis processing (for example, SMASH (SiMultaneous Acquisition of Two-dimensional or three-dimensional image data is reconstructed by performing predetermined image reconstruction processing including Spatial Harmonics) and SENSE (SENSitivity Encoding).

  Further, the image reconstruction unit 106 specifies a dynamic range correction coefficient corresponding to the RF coil 3 based on the identification information of the RF coil 3 transmitted from the sequence control unit 105 together with the k-space data.

  Then, the image reconstruction unit 106 associates the reconstructed image data with the specified dynamic range correction coefficient, and stores the image data in the image data storage unit 103 for each image data.

  The dynamic range correction unit 107 is a processing unit that corrects the dynamic range of image data. Specifically, the dynamic range correction unit 107 reads the image data to be combined from the image data storage unit 103 based on an instruction from the main control unit 104, and sets the dynamic range correction coefficient corresponding to the read image data. Based on this, the dynamic range of each image data is corrected to a predetermined reference value. Then, the dynamic range correction unit 107 holds the image data whose dynamic range is corrected in the internal memory.

  Here, the dynamic range correction unit 107 corrects the image data using the dynamic range correction coefficient determined according to the sensitivity of the RF coil 3, so that the later-described image composition unit 108 is aligned with the same reference. The average value of the pixel values can be calculated from the obtained pixels.

  The image synthesizing unit 108 is a processing unit that performs a stitching process that stitches together image data and synthesizes them into a single image. Specifically, the image composition unit 108 reads out the dynamic range corrected image data held in the dynamic range correction unit 107 based on an instruction from the main control unit 104, and reads the read image data into the body axis. Combine in a direction to compose a single image.

  Here, when the designation of the reference image data has been received by the main control unit 104, the image composition unit 108 is directed toward two directions from the reference image data in opposite directions along the body axis. In each order, for each overlapping portion, the average value of the pixel values of the pixels included in each overlapping portion is calculated, and after correcting the pixel value of each image data so that the calculated average values match, each image Combine the data into a single image.

  On the other hand, when the main control unit 104 has not received the designation of the reference image data, the image composition unit 108 starts from the image data located in the center when the image data are arranged in order in the body axis direction. The average value of the pixel values of the pixels included in each overlapping portion is calculated for each overlapping portion in turn in two directions that are opposite to each other along the axis, and the calculated average values match. After correcting the pixel values of the image data as described above, the image data are connected and combined into one image.

  Here, the above-described stitching process will be described with a specific example. FIG. 3 is a diagram for explaining stitching processing by the image composition unit 108. Here, as shown in the figure, a case is considered in which image data Image1 to Image4 obtained by correcting the dynamic range of four image data Image1 to Image4 are combined into one image.

  When instructed by the main control unit 104 to synthesize image data, the image synthesis unit 108 acquires the images 1 a to 4 a whose dynamic range has already been corrected from the internal memory of the dynamic range correction unit 107. Here, for example, as shown in the figure, it is assumed that Image3 is designated as the reference image data.

  In this case, the image composition unit 108 first calculates the average value (Avg1) of the pixel values included in the overlapping portion of Image2a and Image3a, and is included in the overlapping portion of Image3a based on the calculated average value. A correction coefficient (Ratio) for correcting a pixel included in the overlapping portion of the Image2a so as to coincide with the pixel is calculated (see (1) in the figure). Then, the image composition unit 108 corrects the entire Image 2a using the calculated correction coefficient. Here, the image data obtained by correcting Image2a is hereinafter referred to as Image2b.

  Subsequently, the image composition unit 108 calculates the average value (Avg3) of the pixels included in the overlapped portion of the already corrected Image2b and Image1a, and based on the calculated average value, the overlap of Image2b A correction coefficient (Ratio) for correcting the overlapping portion of the Image 1a so as to coincide with the pixels included in the portion is calculated (see (2) in the figure). Then, the image composition unit 108 corrects the entire Image 1a using the calculated correction coefficient. Here, the image data obtained by correcting Image1a is hereinafter referred to as Image1b.

  Furthermore, the image composition unit 108 calculates the average value (Avg2) of the pixels included in the overlapping portion of Image3a and Image4a, and matches the pixel included in the overlapping portion of Image3a based on the calculated average value. In this manner, a correction coefficient (Ratio) for correcting pixels included in the overlapping portion of the Image 4a is calculated (see (3) in the figure). Then, the image composition unit 108 corrects the entire Image 4a using the calculated correction coefficient. Here, the image data obtained by correcting Image 4a is hereinafter referred to as Image 4b.

  Then, the image composition unit 108 sequentially couples the generated Image2b, Image4b, and Image1b to the Image3a to compose one image (see (4) to (6) in the figure).

  Note that, when the reference screen data is not designated by the operator, the image composition unit 108 sets the image data located at the center when the image data are sequentially arranged in the body axis direction as reference image data. In other words, in the above example, either Image2 or Image3 is set as the reference image data. Thus, when there are an even number of image data to be combined, for example, one image may be randomly selected from the two image data located at the center, or based on the order of the captured stage. Then, the first photographed image may be selected, or the later photographed image may be selected.

  Although the case where four image data are combined into one image data has been described here, the number of image data that can be combined by the MRI apparatus according to the present embodiment is not limited to this, and is less than four. Even if there are five or more sheets, it is possible to perform the stitching process in the same flow.

  In this way, the image composition unit 108 corrects the pixel values of the respective image data so that the average values of the pixels included in the overlapped portions coincide with each other, and then synthesizes the images so that there is a contrast, and the conspicuous joint A wide range of image data can be provided.

  In addition, the image composition unit 108 corrects the pixel values of the other image data in a chain manner based on the designated reference image data, so that a plurality of images are matched with the contrast of the image data selected by the operator. Data can be combined into a single piece of image data, and a wide range of image data can be provided in accordance with the contrast of the image data of the region in which the reader is most interested.

  Further, when the image composition unit 108 does not designate image data from the operator, a plurality of pieces of image data are set to 1 according to the contrast of the image data located in the center when they are arranged in order in the body axis direction. It becomes possible to compose the image data. In many cases, imaging is performed so that the most interesting area is located in the center of the entire imaging area in the medical field, so combining a wide range of image data according to the contrast of the image located in the center is an interpretation. This is very effective in providing easy-to-use image data.

  In any of the above cases, the image composition unit 108 calculates an average value only for pixels included in the overlapped portion and within which the pixel value falls within a predetermined range. The predetermined range used here is, for example, a range obtained by reducing the range from the maximum value to the minimum value of the pixel values of the pixels included in the overlapping portion by a predetermined ratio, and this predetermined ratio is based on an instruction from the operator May be changed. An example of this range setting will be described below with reference to the drawings.

FIG. 4 is a diagram for explaining an example of range setting in the calculation of the average value of pixels by the image composition unit 108. The figure shows a distribution of pixel values of pixels included in the overlapping portion. Specifically, as shown in FIG. 4, the image composition unit 108 calculates a difference D between the maximum value V _max and the minimum value V _min of the pixel values included in the overlapping portion, Then, L is derived by multiplying by a predetermined ratio R (0 <R <1). Then, the image composition unit 108 sets the derived L as a predetermined range.

  Here, the image composition unit 108 calculates an average value only for pixels whose pixel values are within a predetermined range, so that among the pixels included in the overlapping portion, those having no pixel value or abnormal pixels. Even if there is a value, those pixels can be excluded from the average value calculation target, and adverse effects on correction due to unnatural pixels can be suppressed. This makes it possible to provide a wide range of images with smoother joints.

  Here, the case where the predetermined range is set using the range from the maximum value to the minimum value of the pixel value and the predetermined ratio has been described, but the range is set using two predetermined constants. Alternatively, the range may be set using a value obtained by subtracting a constant of a predetermined size from the maximum value and a value obtained by adding a constant of a predetermined size to the minimum value. Good.

  Although the case where the image composition unit 108 uses an average value as an index value has been described here, for example, a maximum value, a minimum value, a median value, a mode value, or the like may be used. In addition, the index value indicates the number of pixels whose pixel values fall within a predetermined range, the number of pixels whose pixel values exceed a predetermined threshold, and the number of pixels whose pixel values are smaller than the predetermined threshold among the pixels included in the overlapping portion. It is good.

  Next, a processing procedure of stitching processing by the computer 100 according to the present embodiment will be described. FIGS. 5 and 6 are flowcharts (1) and (2) showing the processing procedure of the stitching process by the computer 100 according to the present embodiment. Here, the case where the image data 1 to N are combined will be described. In FIGS. 5 and 6, “image data” is simply “image” in order to simplify the illustration.

  In the computer 100, when the imaging of each part of the subject P is completed, the main control unit 104 reads the reconstructed image data 1 to N from the image data storage unit 103 as shown in the figure (step S101). ) The read image data 1 to N are displayed on the display unit 102 (step S102). FIG. 7 is a diagram showing an example of image data before synthesis, and shows a case where five pieces of image data i1 to i5 taken for each part are displayed.

  When the main control unit 104 receives the designation of the image data 1 to N as the synthesis target, the dynamic range correction unit 107 reads the image data 1 to N from the image data storage unit 103 and sets the dynamic range of each image data to a predetermined value. Is corrected to the reference value (step S103).

  Subsequently, when the main control unit 104 receives a compositing instruction, when the reference image data n is simultaneously designated (Yes in step S104), the image composition unit 108 uses the designated image data n as the reference image. (Step S105). On the other hand, if the reference image data n is not designated (No in step S104), the image composition unit 108 uses the image data n located in the center as the reference image when sequentially arranged in the body axis direction. It sets (step S106).

  Then, when there is image data n−1 (step S107, Yes), the image composition unit 108 calculates an average value of pixels included in the overlapping portion between the image data n and the image data n−1 (step S107). S108) Based on the calculated average value, a correction coefficient for correcting the pixel included in the overlapping portion of the image data n-1 so as to coincide with the pixel included in the overlapping portion of the image data n is calculated (step S108). S109).

  Subsequently, the image composition unit 108 corrects the image data n-1 using the calculated correction coefficient (step S110), and sets the image data n-1 as a reference image (sets n-1 to n). (Step S111).

  The image synthesizing unit 108 repeats the above-described processing from steps S108 to S111 as long as there is image data n-1, and when there is no more image data n-1 (that is, when the processing up to image data 1 is completed). (No in step S107), as shown in FIG. 6, the image data n initially set as the reference image data is set again as the reference image data (step S112).

  Then, when there is image data n + 1 (step S113, Yes), the image composition unit 108 calculates an average value of pixels included in the overlapping portion between the image data n and the image data n + 1 (step S114). Based on the average value, a correction coefficient for correcting pixels included in the overlapping portion of the image data n + 1 so as to match the pixels included in the overlapping portion of the image data n is calculated (step S115).

  Subsequently, the image composition unit 108 corrects the image data n + 1 using the calculated correction coefficient (step S116), and sets the image data n + 1 as a reference image (n + 1 is set to n) (step S117).

  The image synthesizing unit 108 repeats the above-described processing from steps S114 to S117 as long as there is image data n + 1, and when there is no more image data n + 1 (that is, when processing to image data N is completed) (step S113). , No), the corrected image data 1 to N are connected and combined into one image (step S118).

  The main control unit 104 displays the image data combined by the image combining unit 108 on the display unit 102 (step S119). FIG. 8 is a diagram illustrating an example of the image data after combining, and illustrates a case where the five pieces of image data i1 to i5 illustrated in FIG. 7 are combined.

  In the above processing procedure, the image data is corrected in order from one of the reference image data in order toward one of the images, and then the image data is corrected in order from the first reference image data to the other. However, the order of correction is not limited to this, and correction may be performed alternately in the opposite direction. After calculating all the correction coefficients, each image data is corrected in random order. Also good.

  As described above, in this embodiment, the image data storage unit 103 associates a plurality of reconstructed image data with information related to the reception coil that detects the magnetic resonance signal that is the basis of each image data. The dynamic range correction unit 107 sets the dynamic range of each image data for each image data stored in the image data storage unit 103 based on information related to the receiving coil corresponding to each image data. Since the image composition unit 108 corrects the reference value and combines the image data whose dynamic range has been corrected by the dynamic range correction unit 107 in the body axis direction to compose a single image, the sensitivity of the receiving coil is different. Even if they are different, the image data can be smoothly joined together.

  By the way, in imaging using an MRI apparatus, a plurality of stages may be set for each part in one imaging, and a plurality of sections of the part may be imaged with one stage. The present invention can be similarly applied to such a case. That is, in this embodiment, each image data is set as a processing unit. However, based on the image data group captured for each stage as a processing unit, dynamic range correction and pixels included in the overlapping portion are used. Correction is performed, and then a plurality of image data groups are connected to form one image data group.

  In the present embodiment, the case where one computer 100 performs processing related to display of image data has been described. However, the present invention is not limited to this. For example, an image server that stores image data and an image server are used. The present invention can be similarly applied to an image display system in which a computer for displaying stored image data is connected via a network.

  In this case, the image server holds a plurality of reconstructed image data in association with information related to the reception coil that detects the MR signal that is the basis of each image data, and the computer is held in the image server. For each image data, the dynamic range is corrected based on the information related to the receiving coil corresponding to each image data, and each image data with the corrected dynamic range is connected in the body axis direction to obtain a single sheet. Composite to the image.

  As described above, the magnetic resonance imaging apparatus, the image display apparatus, the image display program, and the image display system according to the present invention connect images captured using a plurality of receiving coils to combine them into one image. This is useful, and is particularly suitable when the sensitivity of the receiving coil used for imaging varies from receiving coil to receiving coil.

It is a functional block diagram which shows the structure of the MRI apparatus which concerns on a present Example. FIG. 3 is a functional block diagram showing a configuration of software executed by the computer shown in FIG. 2. It is a figure for demonstrating the stitching process by an image synthetic | combination part. It is a figure for demonstrating an example of the range setting in the average value calculation of the pixel by an image synthetic | combination part. It is a flowchart (1) which shows the process sequence of the stitching process by the computer concerning a present Example. It is a flowchart (2) which shows the process sequence of the stitching process by the computer concerning a present Example. It is a figure which shows an example of the image data before a synthesis | combination. It is a figure which shows an example of the image data after a synthesis | combination.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Static magnetic field magnet 2 Gradient magnetic field coil 3 RF coil 4 Static magnetic field power supply 5 Gradient magnetic field power supply 6 Transmitter 7 Receiver 8 Sequence control apparatus 100 Computer 101 Input part 102 Display part 103 Image data storage part 104 Main control part 105 Sequence control part 106 Image reconstruction unit 107 Dynamic range correction unit 108 Image composition unit

Claims (8)

A magnetic resonance imaging apparatus for reconstructing a plurality of image data partially overlapping from each of magnetic resonance signals detected by a plurality of receiving coils mounted on a subject,
Image data storage means for storing a plurality of reconstructed image data and information related to the receiving coil that detects the magnetic resonance signal that is the basis of each image data;
Correction means for performing correction for matching the dynamic range of each image data based on information related to the receiving coil corresponding to each image data for each image data stored by the image data storage means;
While calculating a predetermined index value from the pixel values of the pixels included in the overlapping portion for each overlapping portion of the image data having the same dynamic range by the correction means , the plurality of image data are sequentially arranged in the body axis direction. With the image data located in the center when aligned, the pixel value of each image data located on both sides of the image data is corrected so that it matches the index value of the image data , and then each image data is Image composition means for combining in the body axis direction and compositing into one image;
A magnetic resonance imaging apparatus comprising:   The magnetic resonance imaging apparatus according to claim 1, wherein the index value is an average value of pixel values included in overlapping portions of the image data. A reference screen receiving means for receiving designation of image data serving as a reference from among the reconstructed image data;
When the image data designation is accepted by the reference screen accepting means, the image synthesizing means sequentially in the two directions from the designated image data toward the opposite directions along the body axis. In addition, while calculating the index value for each overlapping portion, the pixel value of each image data located on both sides of the image data is matched with the index value of the image data with reference to the designated image data. 3. The magnetic resonance imaging apparatus according to claim 1 , wherein after correction, each image data is connected in a body axis direction to be combined into a single image . The image synthesizing means, if the specified image data has not been received by the reference picture receiving unit, along the image data positioned in front in the Symbol central body axis in two directions toward the opposite directions Each of the image data located on both sides of the image data so as to coincide with the index value of the image data with the image data located at the center as a reference while calculating the index value for each overlapping portion in turn. 4. The magnetic resonance imaging apparatus according to claim 3 , wherein after correcting the pixel value of the image data, the respective image data are connected in the body axis direction and synthesized into one image .   The image composition means sets the pixel value among the pixels included in the overlapping portion using at least one of the maximum value, the minimum value, and a predetermined constant of the pixel values of the pixels included in the overlapping portion. 5. The magnetic resonance imaging apparatus according to claim 1, wherein the index value is calculated only for an object that falls within a specified range. An image display device for displaying a plurality of partially overlapping image data reconstructed from magnetic resonance signals detected by a plurality of receiving coils mounted on a subject,
Image data storage means for storing a plurality of reconstructed image data and information related to the receiving coil that detects the magnetic resonance signal that is the basis of each image data;
Correction means for performing correction for matching the dynamic range of each image data based on information related to the receiving coil corresponding to each image data for each image data stored by the image data storage means;
While calculating a predetermined index value from the pixel values of the pixels included in the overlapping portion for each overlapping portion of the image data having the same dynamic range by the correction means , the plurality of image data are sequentially arranged in the body axis direction. With the image data located in the center when aligned, the pixel value of each image data located on both sides of the image data is corrected so that it matches the index value of the image data , and then each image data is Image composition means for combining in the body axis direction and compositing into one image;
An image display device comprising: An image display program for displaying a plurality of image data reconstructed from magnetic resonance signals detected by a plurality of receiving coils mounted on a subject,
An image data storage procedure for storing a plurality of reconstructed image data and information related to the receiving coil that has detected the magnetic resonance signal that is the basis of each image data in a storage device in association with each other,
For each image data stored by the image data storage procedure , a correction procedure for performing correction to match the dynamic range of each image data based on information related to the receiving coil corresponding to each image data;
While calculating a predetermined index value from the pixel values of the pixels included in the overlapping portion for each overlapping portion of the image data having the same dynamic range by the correction procedure , the plurality of image data are sequentially arranged in the body axis direction. With the image data located in the center when aligned, the pixel value of each image data located on both sides of the image data is corrected so that it matches the index value of the image data , and then each image data is An image compositing procedure that stitches together in the body axis direction to compose one image,
An image display program for causing a computer to execute. An image server device for storing a plurality of partially overlapping image data reconstructed from magnetic resonance signals detected by a plurality of receiving coils mounted on a subject, and image data stored in the image server device An image display system comprising an image display device for displaying,
The image server device
Image data storage means for storing a plurality of reconstructed image data and information related to the receiving coil that detects the magnetic resonance signal that is the basis of each image data,
The image display device
Correction means for performing correction for matching the dynamic range of each image data based on information related to the receiving coil corresponding to each image data for each image data stored by the image data storage means;
While calculating a predetermined index value from the pixel values of the pixels included in the overlapping portion for each overlapping portion of the image data having the same dynamic range by the correction means , the plurality of image data are sequentially arranged in the body axis direction. With the image data located in the center when aligned, the pixel value of each image data located on both sides of the image data is corrected so that it matches the index value of the image data , and then each image data is Image composition means for combining in the body axis direction and compositing into one image;
An image display system comprising:

Images