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JP-7856444-B2 - Medical information processing device, medical information processing method, method for acquiring calibration information, and program

JP7856444B2JP 7856444 B2JP7856444 B2JP 7856444B2JP-7856444-B2

Inventors

  • 舟迫 慎太郎

Assignees

  • キヤノンメディカルシステムズ株式会社

Dates

Publication Date
20260511
Application Date
20220204

Claims (11)

  1. A storage unit that stores multiple pieces of correspondence information for each body shape, showing the correspondence between pixel values of medical images created by scanning at least two different body shape phantoms and predetermined biometric indicators, An acquisition unit that acquires body shape information about the subject to be scanned, A selection unit identifies the corresponding information that corresponds to the body shape information from among the multiple corresponding information stored in the memory unit, Equipped with , The aforementioned phantom includes an absorber region and a biocomponent region. The system further includes a calibration unit that obtains calibration information by deriving a first correspondence between biological components and biological indicators from medical images scanned with different concentrations of biological components for each of the at least two different phantom shapes and sizes, deriving a second correspondence between energy and pixel values from medical images scanned with multiple types of energy and pixel values, and deriving a third correspondence between the absorber size and the second correspondence. Medical information processing device.
  2. A storage unit that stores multiple pieces of correspondence information for each body shape, showing the correspondence between pixel values of medical images created by scanning at least two different body shape phantoms and predetermined biometric indicators, An acquisition unit that acquires body shape information about the subject to be scanned, A selection unit identifies the corresponding information that corresponds to the body shape information from among the multiple corresponding information stored in the memory unit, Equipped with , The identifying unit acquires bone regions and soft tissue regions from a medical image obtained by scanning the subject, identifies a correspondence relationship derived by scanning with multiple types of energy based on the pixel values of the acquired bone regions and soft tissue regions and the absorber size of the subject, and identifies the bone density of the bone region included in the medical image of the subject based on the identified correspondence relationship. Medical information processing device.
  3. The identification unit identifies predetermined biometric indicators from the pixel values of a medical image created by scanning the subject, based on the correspondence information corresponding to the identified body shape information. A medical information processing device according to claim 1 or 2 .
  4. The aforementioned medical images were acquired based on medical data scanned with multiple types of energy. A medical information processing device according to any one of claims 1 to 3 .
  5. The aforementioned correspondence information includes a relational expression for identifying a predetermined biometric from the pixel values of the medical image. A medical information processing device according to any one of claims 1 to 4 .
  6. The aforementioned biological component is hydroxyapatite, and the aforementioned biological indicator is bone density. The medical information processing device according to claim 1 .
  7. Computers Multiple pieces of correspondence information, showing the relationship between pixel values of medical images created by scanning at least two different body shape phantoms and predetermined biometric indicators, are stored for each body shape. Obtain body shape information about the subject being scanned, From the multiple pieces of stored correspondence information, identify the correspondence information that corresponds to the body shape information. The aforementioned phantom includes an absorber region and a biocomponent region. For each of the two different phantom shapes and sizes, a first correspondence between biological components and biological indicators is derived from medical images scanned with varying concentrations of biological components; a second correspondence between energy and pixel values is derived from medical images scanned with multiple types of energy and pixel values; and a third correspondence between the absorber size and the second correspondence is derived to obtain calibration information. Medical information processing method.
  8. Computers Multiple pieces of correspondence information, showing the relationship between pixel values of medical images created by scanning at least two different body shape phantoms and predetermined biometric indicators, are stored for each body shape. Obtain body shape information about the subject being scanned, From the multiple pieces of stored correspondence information, identify the correspondence information that corresponds to the body shape information. The system obtains bone and soft tissue regions from medical images obtained by scanning the subject, identifies correspondences derived from scans using multiple energy levels based on the pixel values of the acquired bone and soft tissue regions and the absorber size of the subject, and identifies the bone density of the bone region included in the medical image of the subject based on the identified correspondences. Medical information processing method.
  9. Computers For each of at least two different phantoms of different body shapes and sizes, a first correspondence between biological components and biological indicators is derived from medical images scanned with varying concentrations of biological components within the phantom. A second correspondence between energy and pixel value was derived from medical images scanned with multiple types of energy and their corresponding pixel values. Calibration information is obtained by deriving a third correspondence between the absorber size of the phantom and the second correspondence. How to obtain calibration information.
  10. On the computer, By scanning phantoms of at least two different body shapes and sizes, the system stores multiple pieces of correspondence information for each body shape, showing the relationship between the pixel values of the medical images and predetermined biometric indicators. To obtain body shape information about the subject being scanned, From the multiple stored correspondence pieces of information, identify the correspondence piece that corresponds to the body shape information. The aforementioned phantom includes an absorber region and a biocomponent region. For each of the two different phantoms of varying body shapes and sizes, a first correspondence between biological components and biological indicators is derived from medical images scanned with different concentrations of biological components; a second correspondence between energy and pixel values is derived from medical images scanned with multiple types of energy and pixel values; and a third correspondence between the absorber size and the second correspondence is derived to obtain calibration information. program.
  11. On the computer, By scanning phantoms of at least two different body shapes and sizes, the system stores multiple pieces of correspondence information for each body shape, showing the relationship between the pixel values of the medical images and predetermined biometric indicators. To obtain body shape information about the subject being scanned, From the multiple stored correspondence pieces of information, identify the correspondence piece that corresponds to the body shape information. The system obtains bone and soft tissue regions from medical images obtained by scanning the subject, identifies correspondences derived from scans using multiple energy levels based on the pixel values of the acquired bone and soft tissue regions and the absorber size of the subject, and identifies the bone density of the bone region included in the medical image of the subject based on the identified correspondences. program.

Description

Embodiments of the present invention relate to a medical information processing device, a medical information processing method, a method for acquiring calibration information, and a program. Conventionally, bone density measurement using X-ray CT (Computed Tomography) devices is known. Since bone density values vary depending on the beam hardening effect (BH effect) according to the subject size, conventional methods involve preparing beam hardening calibration tables in advance using multiple body size phantoms, and then using these calibration tables on measured values to determine bone density while considering the influence of subject size. However, this method requires preparing numerous calibration tables suitable for all user body sizes (measured values). Furthermore, actual living organisms have differences in the state of internal organs and the degree of intestinal gas, leading to discrepancies with body size phantoms. Therefore, it was sometimes impossible to efficiently and appropriately identify biological indicators for the subject. Japanese Patent Publication No. 2004-305349Japanese Patent Publication No. 2008-154784Special Publication No. 2004-518501Japanese Patent Publication No. 2008-206560 A diagram showing the configuration of the X-ray CT apparatus 1 according to an embodiment.A diagram showing an example of data stored in memory 41.A diagram showing an example of the functional configuration of the calibration function 57.Figure (1) shows an example of images captured from phantoms of different sizes.Figure (2) shows an example of images captured from phantoms of different sizes.A diagram showing an example of the functional configuration of specific function 58.A diagram showing an example of the first relational expression depending on the size of the absorber surrounding HA.A diagram illustrating the derivation of a second relational equation depending on the size of the absorber.A diagram illustrating how to derive slope information from the second relational equation.A diagram showing the correspondence between absorber size and tilt information.A figure showing an example of a CT image IM30 of a subject.A flowchart showing the sequence of calibration processes for the processing circuit 50.A flowchart showing a series of steps for a specific process in the processing circuit 50. The following describes the embodiment of the medical information processing device, medical information processing method, calibration information acquisition method, and program with reference to the drawings. The medical information processing device is, for example, a medical diagnostic device that processes medical images from an X-ray CT scanner or similar device to diagnose a subject. In the following description, the case where the medical information processing device is an X-ray computed tomography (X-ray CT) scanner will be used as an example. Furthermore, the X-ray CT scanner may be a photon counting type X-ray CT scanner capable of performing photon counting CT. Figure 1 is a configuration diagram of an X-ray CT scanner 1 according to an embodiment. The X-ray CT scanner 1 performs, for example, dual-energy X-ray scanning (dual-energy scanning). Dual-energy scanning can include methods such as using a single X-ray tube and switching the tube voltage applied to the tube to individually irradiate the subject with low-energy and high-energy X-rays, or rapidly switching the tube voltage of the X-ray tube to irradiate the subject with low-energy and high-energy X-rays almost simultaneously. The X-ray CT scanner 1 may perform any method of dual-energy scanning. Furthermore, the X-ray CT scanner 1 may be configured to perform data processing of three or more energy levels (multi-energy). The X-ray CT scanner 1 includes, for example, a stand unit 10, a patient table unit 30, and a console unit 40. Figure 1 shows both a view of the stand unit 10 from the Z-axis direction and a view from the X-axis direction for illustrative purposes; however, in reality, there is only one stand unit 10. In this embodiment, the rotation axis of the rotating frame 17 in the non-tilted state or the longitudinal direction of the top plate 33 of the patient table unit 30 is defined as the Z-axis direction, the axis perpendicular to the Z-axis direction and horizontal to the floor is defined as the X-axis direction, and the direction perpendicular to the Z-axis direction and perpendicular to the floor is defined as the Y-axis direction. The X-ray CT scanner 1 or console unit 40 is an example of a "medical information processing device." The mounting device 10 includes, for example, an X-ray tube 11, a wedge 12, a collimator 13, an X-ray high-voltage device 14, an X-ray detector 15, a data acquisition system (hereinafter referred to as DAS: Data Acquisition System) 16, a rotating frame 17, and a control device 18. The X-ray tube 11 generates X-rays by irradiating thermionic electrons from the cathode (filament) to the anode