JP5858717B2 - Medical image processing device - Google Patents

Description

  Embodiments described herein relate generally to a medical image processing apparatus that displays a breast region.

  Conventionally, X-ray mammography and an ultrasonic diagnostic imaging apparatus have been used for the discovery of breast cancer. However, in recent years, nuclear magnetic resonance imaging has been performed on the chest of a subject. In particular, nuclear magnetic resonance imaging is recommended as a first diagnostic modality for high-risk patients in the United States, and X-ray mammography or ultrasound imaging may be performed thereafter. Further, in the X-ray mammography and the ultrasonic diagnostic imaging apparatus, there is an expression method ABCC'DE for expressing the breast region. Alternatively, there is a method of showing a lesion centered on the nipple and showing the region using the position of a clock hand with respect to the representation of the breast region.

Edited by Japan Society for Imaging and Medical Systems "Medical Image / Radiological Equipment Handbook" Meiko Art Printing Co., Ltd. 2001, p176-177 Pascal A. Baltzer, M.D.; Matthias Dizel.M.D. Et al.syngo BreVis-Efficient and Standardized Workflow for Breast MRI

  However, in the nuclear magnetic resonance imaging apparatus, expressions such as ABCC'DE as seen in X-ray mammography and ultrasonic diagnostic imaging apparatuses, and expressions that indicate the region using the position of the hands of the clock around the nipple are not available. not exist. In addition, there is no standard region representation in breast MRI imaging. Furthermore, there is no technique that indicates in which partial region the lesion region of the subject obtained by nuclear magnetic resonance imaging is present among a plurality of partial regions into which the breast region is divided.

  The purpose is to make it easy to find a lesion area of a breast area on an image found by nuclear magnetic resonance imaging on the image at the time of X-ray mammography or ultrasonic imaging.

The medical image processing apparatus according to the present embodiment includes a volume data storage unit that stores volume data captured by a nuclear magnetic resonance imaging apparatus for a subject's chest, and a nipple of the subject based on the volume data. A nipple region specifying unit for specifying a region, a breast region specifying unit for specifying a breast region by threshold processing from the volume data, and dividing the breast region into a plurality of partial regions based on the specified nipple region. A breast region segmentation unit for segmenting the breast region into the breast region and an extramammary region other than the breast region based on the identified breast region; and at least one subject for the volume data A lesion area identifying unit that identifies a lesion area, and the plurality of portions to which each of the lesion areas of the at least one subject belongs Information specifying one of the regions of the band and the mamma region comprises a, and the lesion area storage unit for storing in association with the volume data.

It is a block diagram of the nuclear magnetic resonance imaging apparatus which concerns on this embodiment. It is the figure which showed the block of the image analysis part 88 of FIG. 1A in detail. It is the figure which showed the position of 14 partial area | regions divided by the area division | segmentation surface, the median line, the boundary line, and the nipple area | region dividing line. It is a flowchart which shows the process sequence regarding the lesion area | region specification in the breast which concerns on embodiment of this invention. It is a figure which shows the area | region display of the divided breast conventionally used with X-ray mammography and an ultrasonic image diagnostic apparatus. It is the flowchart which showed the flow of the mammography used for the woman in the past. It is the flowchart which showed the flow of the mammography used for the female patient with the high risk of the conventional breast cancer. It is a figure which shows the MPR image regarding the axial cross section produced | generated by the MPR image display part 85 of FIG. It is a figure which shows the MPR image regarding the coronal cross section produced | generated by the MPR image display part 85 of FIG. It is a figure which shows the MPR image regarding the sagittal cross section produced | generated by the MPR image display part 85 of FIG. It is the figure which showed the position of the coronal cross section which made the right and left breast area | region object.

  The medical image processing apparatus according to this embodiment will be described below with reference to the drawings. In the following description, components having substantially the same function and configuration are denoted by the same reference numerals, and redundant description will be given only when necessary. The medical image processing apparatus according to this embodiment refers to a nuclear magnetic resonance imaging apparatus, a workstation, or the like. In the following description, the medical image processing apparatus is a nuclear magnetic resonance imaging apparatus.

  First, the configuration of the nuclear magnetic resonance imaging apparatus according to the present embodiment will be described. FIG. 1A is a diagram for explaining a configuration of a nuclear magnetic resonance imaging apparatus according to the present embodiment. As shown in FIG. 1A, a nuclear magnetic resonance imaging apparatus 100 according to the present embodiment includes a gantry unit 10, a magnetic field application unit 20, a transmission unit 30, an NMR signal reception unit 40, a sequence control unit 50, and a bed. Unit 60, bed control unit 70, and console 80.

  The gantry 10 is a device that detects a magnetic resonance signal emitted from the subject P by irradiating the subject P placed in a static magnetic field with a high-frequency magnetic field, and includes a static magnetic field magnet 11 and a gradient magnetic field coil 12. A transmission RF (Radio Frequency) coil 13 and a reception RF coil 14.

  The static magnetic field magnet 11 is formed in a hollow cylindrical shape and generates a uniform static magnetic field in the internal space. For example, a permanent magnet or a superconducting magnet is used.

  The gradient magnetic field coil 12 is a coil formed in a hollow cylindrical shape, and is disposed inside the static magnetic field magnet 11. The gradient coil 12 is formed by combining three coils corresponding to the X, Y, and Z axes orthogonal to each other. The three coils described above receive a current supply individually from the magnetic field application unit 20 described later, and generate a gradient magnetic field in which the magnetic field strength changes along the X, Y, and Z axes. The Z-axis direction is the same as the static magnetic field.

  Further, the gradient magnetic fields of the X, Y, and Z axes generated by the gradient magnetic field coil 12 correspond to, for example, the slice selection gradient magnetic field Gs, the phase encoding gradient magnetic field Ge, and the readout gradient magnetic field Gr, respectively. The slice selection gradient magnetic field Gs is used to arbitrarily determine an imaging section. The readout gradient magnetic field Gr is used for changing the frequency of the magnetic resonance signal in accordance with the spatial position.

  The transmission RF coil 13 is disposed inside the gradient magnetic field coil 12 and generates a high-frequency magnetic field when a high-frequency pulse is supplied from a transmission unit 30 described later.

  The reception RF coil 14 is disposed inside the gradient magnetic field coil 12 and receives a magnetic resonance signal emitted from the subject P due to the influence of the high-frequency magnetic field generated by the transmission RF coil 13.

  The magnetic field application unit 20 supplies a current to the gradient magnetic field coil 12. The transmission unit 30 transmits a high-frequency pulse corresponding to the Larmor frequency to the transmission RF coil 13. The receiving unit 40 generates raw data by digitizing the magnetic resonance signal output from the receiving RF coil 14.

  The sequence control unit 50 controls the scanning of the subject P by driving the magnetic field application unit 20, the transmission unit 30, and the NMR signal reception unit 40 based on the sequence information transmitted from the console 80. When the raw data is transmitted from the NMR signal receiving unit 40 as a result of scanning the subject P, the sequence control unit 50 transfers the raw data to the console 80.

  “Sequence information” refers to the strength of power supplied from the magnetic field application unit 20 to the gradient magnetic field coil 12, the timing of supplying power, the strength of the high-frequency pulse transmitted from the transmission unit 30 to the transmission RF coil 13, This is information defining a procedure for performing a scan, such as a timing at which a high-frequency pulse is transmitted and a timing at which the receiving unit 40 detects an NMR signal.

  The couch portion 60 includes a top plate 61 on which the subject P is placed, and the gradient magnetic field coil 12 is placed on the top plate 61 in a state where the subject P is placed under the control of a couch control portion 70 described later. Is inserted into the cavity (imaging port). Normally, the bed part 60 is installed so that the longitudinal direction is parallel to the central axis of the static magnetic field magnet 11. Here, for the subject P, for example, the receiving RF coil 14 for breast imaging is attached to the subject P placed on the top board 61.

  The bed control unit 70 drives the bed unit 60 to move the top 61 in the longitudinal direction and the vertical direction.

  The console 80 performs overall control of the nuclear magnetic resonance imaging apparatus 100, data collection, image reconstruction, and the like, and includes an interface unit 81, a storage device 83, an input unit 84, an MPR image display unit 85, and a volume data generation unit 86. Have.

  The interface unit 81 controls input / output of various signals exchanged with the sequence control unit 50. For example, the interface unit 81 transmits sequence information to the sequence control unit 50. The interface unit 81 receives raw data from the sequence control unit 50.

  The raw data received by the interface unit 81 includes the slice selection gradient magnetic field Gs, the phase encoding gradient magnetic field Ge, and the readout gradient magnetic field Gr generated by the gradient magnetic field coil 12 in the SE (Slice Encode) direction, PE ( It is stored in the storage device 83 as k-space data in which spatial frequency information in the phase Encode) direction and RO (Read out) direction is associated.

  In addition, the interface unit 81 transmits a bed movement request input via the input unit 84 described later to the bed control unit 70. Further, the bed control unit 70 drives the bed unit 60 based on the received bed movement request.

  The storage device 83 stores k-space data transferred from the interface unit 81, volume data generated by the data processing unit 82, and the like for each subject P.

  The volume data generator 86 generates volume data for the chest of the subject based on the output of the NMR signal receiver 40.

  The MPR image generator 87 generates an MPR image for the breast region of the subject from the volume data.

  The image analysis unit 88 displays an area division plane or specifies a lesion area. Detailed contents of the image analysis unit 88 will be described later.

  The input unit 84 includes a pointing device such as a mouse and a trackball for receiving various instructions and information input from the user, a selection device such as a mode change switch, or an input device such as a keyboard.

  The MPR image display unit 85 is a monitor referred to by the user, and displays various information such as a magnetic resonance image to the user, and displays a GUI (Graphical User Interface) for receiving a command from the user via the input unit 84. To do.

  Hereinafter, this main feature will be described with reference to FIGS. 1B to 9 together with FIG. 1A. FIG. 1B is a diagram illustrating the image analysis unit 88 according to the present embodiment in more detail. FIG. 2 is a diagram showing the positions of 14 partial areas divided by the area dividing plane, the median line, the boundary line, and the nipple area dividing line. FIG. 3 is a flowchart from when the volume data is stored in the storage device 83 until the partial area to which the lesion area belongs is specified. FIG. 4 is a diagram showing a breast region display used in clinical practice. FIG. 5A is a flowchart of mammography used for women. FIG. 5B is a flowchart of mammography used for women at high risk of breast cancer in conventional mammography. 6 to 8 are MPR images of a coronal section, an axial section, and a sagittal section generated by the MPR image generation unit 87 of FIG. FIG. 9 is a diagram showing the position of the coronal section for the left and right breast regions.

  FIG. 1B shows the image analysis unit 88 in more detail. FIG. 1B shows a nipple region specifying unit 821, a breast region specifying unit 822, a breast region segmenting unit 823, and a region dividing plane determining unit 824, a lesion region specifying unit 825, a memory unit 826, a midline specifying unit 827, and a boundary line. A specifying unit 828. The nipple region specifying unit 821 specifies the nipple region from the volume data by threshold processing. The nipple region detection unit 822 detects the nipple region of the subject based on the volume data generated by the volume data generation unit 86. The breast area specifying unit 822 specifies the left and right breast areas from the volume data by threshold processing. The breast region classification unit 823 divides the breast region into a plurality of partial regions based on the detected nipple region, and divides the breast region into a breast region and an extramammary region other than the breast region based on the identified breast region. Divide into Based on the position of the detected nipple region, the region dividing surface determination unit 824 includes a first region dividing surface that passes through the left nipple region and is parallel to the axial surface, and a second region that passes through the left nipple region and is parallel to the sagittal surface. An area dividing plane, a third area dividing plane passing through the right papillary area and parallel to the axial plane, and a fourth area dividing plane passing through the right papillary area and parallel to the sagittal plane are determined. The lesion area specifying unit 825 specifies the lesion area of the subject for the volume data. The memory unit 826 is a storage device having a configuration that combines elements such as a read only memory (ROM) and a random access memory (RAM). The memory unit 826 stores IPL (initial program loading) and BIOS (basic input / output system) data, and is used for temporary storage of CPU work memory and data. The midline specifying unit 827 specifies the position of the midline passing through the center of the subject based on the position of the nipple region specified by the nipple region specifying unit 821. The boundary line specifying unit 828 specifies a boundary line for distinguishing between the subject and other than the subject by threshold processing.

  The details of the flowchart for specifying the partial area to which the lesion area belongs will be described below with reference to FIG.

  In S <b> 11, the volume data generated by the volume data generation unit 86 based on the output of the NMR signal reception unit 40 is stored in the storage device 83.

  In S12, the breast region specifying unit 822 specifies two left and right breast regions (A, B, C, D) in FIG. 8 by threshold processing for volume data. As an example, a method such as a region expansion method is used. The region expansion method gives a pixel (seed point) as a starting point designated by the operator in the lung field region, and sequentially integrates adjacent pixels based on the similarity of density values in the input image. This is a process of extracting a certain area.

  In S13, the nipple region specifying unit 821 specifies the two left and right nipple regions E and J in FIG. 3 for volume data.

  In S14, the midline specifying unit 827 specifies the position of the midline 111 in FIG. 3 based on, for example, the position of the center of gravity of the nipple region specified in S13.

  In S15, the boundary line specifying unit 828 specifies the boundary lines 120 and 121 between the subject and the outside of the subject in FIG. 3 by threshold processing.

  In S16, the region dividing plane determining unit 824 targets the inside of the left and right breast areas specified in S12, and intersects at the position of the center of gravity of the nipple area as shown in FIG. The positions of the area dividing plane 117 and the first area dividing plane 119 and the positions of the fourth area dividing plane 116 and the second area dividing plane 118 parallel to the sagittal plane are determined. The positions of the first region dividing surface 119 and the third region dividing surface 117 are independently determined on the left and right sides based on, for example, the positions of the center of gravity of the left and right nipple regions. Similarly, the position of the second region dividing surface 118 and the position of the fourth region dividing surface 116 are also determined independently on the left and right sides based on, for example, the positions of the center of gravity of the left and right nipple regions. After that, when the user inputs information for finely adjusting the area dividing plane to an input device such as a mouse or a keyboard, the position of the area dividing plane is finely adjusted, and the final position of the area dividing plane is determined. The

  In S17, the breast region segmenting unit 823 segments the right breast region into four partial regions (A, B, C, and D in FIG. 2) excluding the papillary region based on the region dividing plane determined in S16. At the same time, the left breast region is divided into four partial regions (A, B, C, and D in FIG. 2) excluding the nipple region. At the same time, the breast region is divided into a breast region (A, B, C, D, E in FIG. 2) and an extramammary region (C ′ in FIG. 2) other than the breast region based on the breast region specified in S12. To do. Further, the areola region E and the other regions (A, B, C, C ′, D) are divided by the teat region dividing line (113 and 115 in FIG. 2) specified in S13. Further, the areola region E and the nipple region E ′ are distinguished based on the shape. The breast region is divided into 14 partial regions (A, B, C, C ′, D, E, E ′ in FIG. 2) by the above processing in S <b> 17. A is the inner upper part in the breast area, B is the inner lower part in the breast area, C is the outer upper part in the breast area, D is the outer lower part in the breast area, E is the areola area, and E 'is the nipple area. . C ′ indicates a region where lymph nodes are concentrated near the eyelid of the subject.

  In S18, the lesion area identification unit 825 identifies the lesion area from the volume data by threshold processing. Even when there are a plurality of lesion areas, a lesion area is specified for each of the plurality of lesion areas.

  In S19, in the storage device 83, information specifying any one of a plurality of partial regions and an extramammary region to which each of the lesion regions of at least one subject belongs is stored in association with the volume data. Even when there are a plurality of lesion areas, information for specifying the partial area to which the lesion area belongs is stored in association with the volume data for each of the plurality of lesion areas. When the lesion area extends over a plurality of partial areas, as an example, the partial area to which the lesion area belongs is specified based on the area where the lesion area and the partial area overlap.

  FIG. 4 is a diagram showing the right breast region and lymph nodes around the breast region. As shown in FIG. 4, the right breast region is roughly divided into six areas A, B, C, C ′, D, and E. 4A shows an inner upper part in the breast area, B shows an inner lower part in the breast area, C shows an outer upper part in the breast area, D shows an outer lower part in the breast area, and E shows an areola area. C ′ indicates a region where lymph nodes are concentrated near the eyelid of the subject. In the case of the left breast, the signs A, B, C, and D are bilaterally symmetrical about the subject's midline. The incidence of breast cancer in each region is approximately 25% A region, 10% B region, 50% C and C 'region, and 10% D region. In particular, the C ′ region is a site having a large number of lymph nodes, and it is generally known that the occurrence frequency of breast cancer is high.

  FIG. 5A is a flow of mammography used for a woman who has a high risk of breast cancer. First, an image is taken with an X-ray mammography or an ultrasonic diagnostic imaging apparatus. Next, when the user views the image and determines that there is no lesion area, the breast imaging is terminated. When a benign cancer is found, the doctor observes the course of the cancer in the patient's body. If it is doubtful that the cancer is benign, then nuclear magnetic resonance imaging is performed.

  FIG. 5B is a mammography flow used for women at high risk of breast cancer. It is recommended that women at high risk of breast cancer be imaged once a year using a nuclear magnetic resonance imaging system. Therefore, imaging is first performed using a nuclear magnetic resonance imaging apparatus. Next, if the user looks at the image obtained by imaging with a nuclear magnetic resonance imaging apparatus and determines that there is no diseased part or that a cancer exists but is a benign cancer, the doctor Observe the progress of cancer in the body. If you suspect that the cancer is benign, perform a biopsy, such as a blood test. Thus, after imaging with a nuclear magnetic resonance imaging apparatus, clinical needs have arisen for performing X-ray mammography and ultrasonic imaging in order to further examine the affected area more precisely.

  6 to 8 are MPR images related to a coronal section, a sagittal section, and an axial section. FIG. 6 is an MPR image in an axial cross section. Second region dividing planes 102 and 103 are displayed so as to pass through the center of gravity of the right nipple region 100 and the center of gravity of the left nipple region 101. FIG. 7 is an MPR image in a coronal section. Area division planes 104, 105, 107, and 108 are displayed so as to pass through the center of gravity of the right nipple region 106 and the center of gravity of the left nipple region 107. In addition, the right breast and the left breast in FIG. 7 are composite images that are MPR processed independently on the left and right and arranged side by side. FIG. 8 is an MPR image in a sagittal section. The area dividing surface 109 is displayed so as to pass through the center of gravity of the nipple area 110.

  FIG. 9 is a diagram schematically showing the position of the coronal section for the left and right breast regions. As shown in FIG. 9, coronal cross-section MPR images having different depths with respect to the coronal direction are generated independently on the left and right. Thereafter, an MPR image is generated by synthesizing two coronal cross-section MPR images as shown in FIGS. 6 and 7.

  As described above, as an effect of the present invention, it is possible to easily identify a lesion area of a breast in a three-dimensional image taken by a nuclear magnetic resonance imaging apparatus. Further, when comparing a three-dimensional image taken by a nuclear magnetic resonance imaging apparatus with an image of an X-ray mammography apparatus or an ultrasonic diagnostic imaging apparatus, it becomes possible to easily identify the same lesion area.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 10 ... Mount part, 11 ... Static magnetic field magnet, 12 ... Gradient magnetic field coil, 13 ... RF coil for transmission, 14 ... RF coil for reception, 20 ... Gradient magnetic field power supply, 30 ... Transmission part, 40 ... Reception part, 50 ... Sequence Control unit 60 ... Bed unit 61 ... Top plate 62 ... Second display unit 63 ... Stimulus generating device 64 ... Stimulus generating device console 70 ... Bed control unit 80 ... Console 81 ... Interface unit 82 ... Data processing unit, 83 ... Storage device, 84 ... Input unit, 85 ... Display unit, 86 ... Volume data generation unit, 87 ... MPR image generation unit, 88 ... Image analysis unit, 100 ... MRI apparatus, 100 ... Right papillary region , 101 ... Left nipple region, 102 ... Second region dividing surface, 103 ... Fourth region dividing surface, 104 ... Fourth region dividing surface, 105a ... Third region dividing surface, 105b ... First region dividing Face, 108 ... second area dividing plane, 109 ... area dividing plane parallel to the axial plane, 101, 106, 110 ... papillary area, 111 ... midline, 112 ... right breast area dividing line, 113 ... right areola area dividing line, 114: left breast area dividing line, 115: left areola area dividing line, 116: fourth area dividing plane, 117: third area dividing plane, 118: second area dividing plane, 119: first area Dividing plane, 120 ... boundary line that distinguishes subject and non-subject from right breast, 121 ... boundary line that distinguishes left breast from subject and non-subject, 122 ... intended for right breast MPR image of coronal section, 123... MPR image of coronal section for breast, 821... Nipple region specifying unit, 822... Breast region specifying unit, 823 .. breast region segmenting unit, 824. Lesion area identification part 826 ... memory portion, 827 ... midline specific section, 828 ... borderline determining portion

Claims (2)

A volume data storage unit for storing volume data captured by a nuclear magnetic resonance imaging apparatus for the chest of the subject;
Based on the volume data, a nipple region specifying unit for specifying a nipple region of the subject;
From the volume data, a breast region specifying unit that specifies a breast region by threshold processing,
The breast area is divided into a plurality of partial areas based on the identified nipple area, and the breast area is divided into the breast area and an extramammary area other than the breast area based on the identified breast area. A breast region segmentation section to be segmented;
A lesion area specifying unit that specifies a lesion area of at least one subject for the volume data;
Each of the plurality of partial areas to which each of the lesion areas of the at least one subject belongs and the
Information that identifies one of the areas outside the breast is associated with the volume data
A lesion area storage unit for storing
A medical image processing apparatus comprising: A region dividing surface determination unit that determines a plurality of dividing surfaces of the specified breast region based on the specified nipple region;
  A display unit that generates an MPR image related to at least one of a coronal section, a sagittal section, and an axial section from the volume data, and displays the plurality of divided surfaces in a synthesized manner;
The medical image processing apparatus according to claim 1, further comprising:

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