JP2017217227A - Radiographic diagnosis apparatus and bone density measurement method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radiographic diagnosis apparatus capable of easily knowing whether a measurement region is appropriately positioned before bone density imaging, and also to provide a bone density measurement method.SOLUTION: Provided is a radiographic diagnosis apparatus 1 capable of acquiring fluoroscopic images, in which a controller 21 detects a measurement region for bone density measurement from a fluoroscopic image 50 before bone density imaging, checks if the measurement region is appropriate, and, if not, informs an operator of the effect. For example, an error notification is made if a measurement region (measurement ROI61) including the bone head, greater trochanter, lesser trochanter, and neck of the femur is not contained in an X-ray irradiation field, if another bone such as the ischium is contained in a neck ROI62, if the femur is tilted, or the like. Bone density imaging (two levels of X-ray irradiation, high and low) is made ready when the measurement region is confirmed appropriate for bone density imaging.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an X-ray diagnostic imaging apparatus and a bone density measuring method, and more particularly to positioning of an object in measuring bone density.

For example, DXA (Dual Energy X-Ray)
Absorptiometry) method. In the DXA method, the femur is imaged by irradiating X-rays having two different energy peaks, and a differential image of the two X-ray images is generated to obtain an X-ray image in which only the bone is extracted. In order to obtain an accurate bone density, the region to be measured needs to be accurately positioned (positioned). For example, Patent Document 1 describes a technique for automatically extracting a measurement region using an X-ray image.

JP-A-7-284020

  However, Patent Document 1 describes a technique in which the apparatus automatically sets a measurement target region after performing bone density imaging by the DXA method and generating a provisional difference image, but there is a description regarding positioning of a subject before imaging. Absent. Therefore, if the positioning is not appropriate, the image is re-photographed, and the exposure dose may increase.

  The present invention has been made in view of the above problems, and an X-ray diagnostic imaging apparatus and a bone density measuring method capable of easily knowing whether a measurement region is correctly positioned before bone density imaging. The purpose is to provide.

  In order to achieve the above-described object, the first invention provides an X-ray source that irradiates a subject with a plurality of X-rays having different energy peaks, and transmitted X-rays that are disposed to face the X-ray source and are transmitted through the subject. An X-ray receiver to detect; an image processing unit that generates a fluoroscopic image or an X-ray image corresponding to an energy peak based on the transmitted X-ray; a positioning operation unit that displays the fluoroscopic image and receives a positioning operation; A measurement region detection unit for detecting a measurement region for bone density measurement from the fluoroscopic image, a confirmation processing unit for confirming whether the detected measurement region is appropriate as a measurement region for bone density, and confirmation by the confirmation processing unit A notification unit for notifying the result of the measurement, and generating a difference image from each X-ray image obtained by irradiating the measurement region with X-rays having two types of high and low energy peaks. , A bone density calculation unit for calculating a bone density Zui an X-ray image diagnostic apparatus comprising: a.

  According to a second aspect of the present invention, an X-ray source that irradiates a subject with a plurality of X-rays having different energy peaks, an X-ray receiver that is disposed opposite to the X-ray source and detects transmitted X-rays transmitted through the subject, In an X-ray image diagnostic apparatus including an image processing unit that generates a fluoroscopic image or an X-ray image corresponding to an energy peak based on the transmitted X-ray, a control device displays the fluoroscopic image and receives a positioning operation. A step of detecting a measurement region of bone density measurement from the fluoroscopic image, a step of confirming whether the detected measurement region is appropriate as a measurement region of bone density, and a step of displaying the result of the confirmation And generating a differential image from each X-ray image obtained by irradiating the measurement region with two types of high and low X-rays having different energy peaks, and based on the generated differential image A bone density measurement method, which comprises carrying out a step of calculating, the process comprising a.

  According to the present invention, it is possible to provide an X-ray diagnostic imaging apparatus and a bone density measuring method capable of easily knowing whether or not a measurement region is correctly positioned before bone density imaging.

1 is an overall configuration diagram of an X-ray diagnostic imaging apparatus 1 according to the present invention. Functional configuration diagram related to measurement area confirmation processing in bone density measurement Flow chart showing overall flow of bone density measurement process The flowchart which shows the flow of step S104 (confirmation process) of FIG. Examples of a diaphragm region 51, a direct X-ray region 52, and a subject region 53 that are discriminated from a fluoroscopic image 50 obtained before bone density imaging The figure which shows the example of each site | part detected from the fluoroscopic image 50. FIG. (A) femoral greater trochanter 54, lesser trochanter 55, (b) neck 56, (c) femoral head 57 Example of measurement ROI 61, neck ROI 62, and diaphysis tilt line 63 that are displayed superimposed on fluoroscopic image 50 An example of an error notification screen displayed when the measurement area is not appropriate. (A) Error notification screen 71 when the entire measurement ROI 61 does not enter the X-ray irradiation field, (b) Error notification screen 72 when the cervical ROI 62 includes a sciatic bone The flowchart which shows the flow of the process which confirms the inclination of a diaphyseal part in step S104 (confirmation process) of FIG. The figure explaining calculation of diaphysis inclination (A) Display example of diaphysis tilt line 63 and diaphysis tilt angle 64, (b) Display example of angle between diaphysis tilt line 63 and cervical axis 65 (diaphragm-cervical angle 67) Example of error notification screen 73 when the diaphysis is tilted with respect to the fluoroscopic screen Flow chart explaining the flow of bone density measurement processing using the previous measurement information Example of displaying previous measurement ROI 81 and previous image 82 superimposed on fluoroscopic image 50 being acquired

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[First Embodiment]
First, the overall configuration of the X-ray image diagnostic apparatus 1 will be described with reference to FIG.
As shown in FIG. 1, the X-ray image diagnostic apparatus 1 includes an imaging device 10, an operation device 20, and a bed 15 on which a subject 3 is placed. The imaging device 10 and the operation device 20 are connected by communication using a transmission path such as a communication cable. In the present invention, the imaging device 10 is an imaging device capable of performing both acquisition of a fluoroscopic image and imaging for bone density measurement (hereinafter referred to as bone density imaging).

  The imaging apparatus 10 includes an X-ray source 12, an X-ray diaphragm 13 provided in the X-ray source 12, an X-ray receiver 16 that is disposed to face the X-ray source 12 with a subject 3 interposed therebetween, and the like. Image data based on the transmitted X-ray data detected by the X-ray receiver 16 is transmitted to the controller device 20 via the transmission path. The operation device 20 includes a control device 21, an image processing device 22, a storage device 23, an input device 24, a display device 25, and the like.

  The X-ray source 12 includes an X-ray tube and a high voltage generator, and generates a predetermined dose of X-rays according to a control signal transmitted from the control device 21. The X-ray source 12 continuously irradiates the subject 3 with a low-dose X-ray for fluoroscopy when acquiring a fluoroscopic image. The X-ray source 12 emits X-rays having two different energy peaks at the time of bone density imaging. Hereinafter, X-rays having a high energy peak are referred to as high-energy X-rays, and X-rays having a low energy peak compared to high-energy X-rays are referred to as low-energy X-rays.

  The X-ray source 12 is provided with an X-ray diaphragm 13. The X-ray diaphragm 13 has a plurality of X-ray shielding plates (diaphragm blades), and opens and closes the diaphragm blades to a predetermined position in accordance with the opening information of the diaphragm blades notified from the control device 21. Form an irradiation field.

  The X-ray receiver 16 is a flat panel detector (FPD) in which two-dimensionally arrayed X-ray detection elements constituted by a combination of a scintillator and a photodiode, for example. I. (Image intensifier) or the like, and is provided at a position facing the X-ray source 12 through the subject 3. For example, the X-ray receiver 16 is installed on the lower surface of the top plate of the bed 15.

  Each detection element of the X-ray receiver 16 detects transmitted X-rays, which are X-rays emitted from the X-ray source 12 and transmitted through the subject 3, and converts them into electrical signals corresponding to the X-ray intensity. The X-ray receiver 16 creates an X-ray image based on the transmitted X-ray data that is the converted electric signal. The created X-ray image is a fluoroscopic image (moving image) acquired by fluoroscopic X-rays, a high energy image and a low energy image obtained by bone density imaging, or the like. The created X-ray image is sent to the image processing device 22 of the operation device 20 and stored in the storage device 23.

  The image processing device 22 acquires the X-ray image data transferred from the X-ray receiver 16 and performs image processing for displaying on the display device 25. The image processing includes image processing such as processing for determining the display range by detecting the X-ray aperture position based on pixel value information of the image, black-and-white reverse display processing, unnecessary region deletion, and the like.

  The storage device 23 stores an X-ray image generated based on transmission X-ray data detected by the X-ray receiver 16. In addition, the storage device 23 stores programs relating to imaging and fluoroscopic operations, various imaging conditions, programs and data necessary for bone density measurement processing described later, and the like.

  The control device 21 is a computer including a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like. The control device 21 controls the operation of X-ray irradiation in the X-ray source 12 based on the input signal input from the input device 24, and processes related to the creation of an image and correction of the X-ray aperture position in the X-ray receiver 16. Then, the display device 25 controls the display operation and the like. Moreover, the control apparatus 21 performs the bone density measurement process which measures bone density based on an X-ray image. Details of the bone density measurement process will be described later.

  The display device 25 is configured by a CRT, a liquid crystal panel, or the like, and displays an X-ray image captured by the imaging device 10, display data input from the control device 21, and the like.

  The input device 24 is an input device such as a keyboard and a mouse, for example, and inputs various instructions and information input by the operator to the control device 21. The operator performs operations interactively using external devices such as the display device 25 and the input device 24. Note that the input device 24 may be a touch panel configured integrally with the display screen of the display device 25.

  Next, the functional configuration of the X-ray image diagnostic apparatus 1 according to the present invention will be described with reference to FIG. As shown in FIG. 2, the control device 21 of the X-ray diagnostic imaging apparatus 1 includes a measurement region detection unit 41, a guide display unit 42, a confirmation processing unit 43, a notification unit 44, and a measurement region / X-ray irradiation start position setting unit 45. And a bone density measuring unit 46. The confirmation processing unit 43 includes a measurement region confirmation unit 43a, a cervical ROI confirmation unit 43b, and a femur tilt confirmation unit 43c. The processing operations of the measurement region confirmation unit 43a and the cervical ROI confirmation unit 43b will be described in the first embodiment, and the femoral inclination confirmation unit 43c will be described in the second embodiment.

  Note that the imaging apparatus 10 of the X-ray image diagnostic apparatus 1 acquires a fluoroscopic image 50 for object positioning prior to bone density imaging. The control device 21 receives a positioning operation of the subject 3 while the fluoroscopic image 50 is being acquired in the imaging device 10. The positioning operation is performed via an operation unit (not shown) provided on the photographing apparatus 10 or the bed 15. Alternatively, it is performed via the input device 24 of the console 24.

  The measurement region detection unit 41 detects a measurement region for bone density measurement from the fluoroscopic image 50. The measurement region is a range including the femoral head 57, the greater trochanter 54, the lesser trochanter 55, and the neck 56. Details of the measurement region detection processing will be described later.

  The guide display unit 42 displays a guide mark indicating a measurement region (hereinafter, referred to as a measurement ROI 61) detected by the measurement region detection unit 41 so as to overlap the fluoroscopic image 50. Further, the guide display unit 42 overlaps the fluoroscopic image 50 with a cervical ROI 62 that is a ROI (Region of Interest) indicating the cervical region in the measurement ROI 61, a diaphysis tilt line 63 that represents the tilt of the diaphysis, and the like. indicate. A specific example of display by the guide display unit 42 will be described later.

  The confirmation processing unit 43 confirms whether or not the region detected by the measurement region detection unit 41 is appropriate as the bone density measurement region. The confirmation processing unit 43 includes a measurement region confirmation unit 43a, a cervical ROI confirmation unit 43b, and a femur tilt confirmation unit 43c. The measurement region confirmation unit 43a determines whether or not the entire detected measurement region (measurement ROI 61) is within the X-ray irradiation field. The cervical ROI confirmation unit 43 b extracts the cervical part 56 from the measurement region (measurement ROI 61), sets the ROI (hereinafter referred to as cervical ROI 62) so as to surround the extracted cervical part 56, and the sciatic bone in the cervical ROI 62 It is determined whether bones other than the cervical part 56 are included. The femoral tilt confirmation unit 43c calculates the tilt of the diaphysis and determines whether or not the calculated tilt is within a predetermined allowable range.

  The notification unit 44 notifies the confirmation result by the confirmation processing unit 43. For example, when the measurement ROI 61 does not fit in the X-ray irradiation field, the notification unit 44 displays an error notification screen 71 and notifies the operator to that effect (see FIG. 8A). Further, when the bone other than the neck 56 is included in the neck ROI 62, the notification unit 44 displays an error notification screen 72 to notify that (see FIG. 8B). Alternatively, when the inclination of the diaphysis is outside the predetermined allowable range, an error notification screen 73 or the like is displayed to notify that (see FIG. 12; second embodiment). Note that the notification by the notification unit 44 is not limited to the notification by the error notification screens 71 to 73, and the display color of the corresponding ROI or line may be changed or notified by voice or the like.

  When the confirmation processing unit 43 determines that the positioning is appropriate, the measurement region / X-ray irradiation start position setting unit 45 sets (determines) the measurement region detected by the measurement region detection unit 41 at that time as the measurement ROI 61. To do. Further, the upper end of the measurement ROI 61 is set as the X-ray irradiation start position, the lower end is set as the X-ray irradiation end position, and the left and right of the measurement ROI 61 are set as the aperture position. Note that the measurement ROI 61 may have a predetermined margin to set the X-ray irradiation start position, the X-ray irradiation end position, and the aperture position. When the measurement region / X-ray irradiation start position setting unit 45 sets the X-ray irradiation start position, the X-ray irradiation end position, and the aperture position, the control device 21 generates a control signal according to the information set in the imaging device 10. It transmits to the imaging device 10. The imaging apparatus 10 adjusts the aperture amount of the X-ray diaphragm 13 by moving the position of the video system (X-ray source 12 and X-ray receiver 16) to the X-ray irradiation start position according to the control signal transmitted from the control apparatus 21. To do.

  The bone density measuring unit 46 irradiates each set of X-ray images (high energy image, low energy) by irradiating X-rays having two kinds of high and low energy peaks with respect to the set range from the X-ray irradiation start position to the X-ray irradiation end position. Energy image). The low energy image is an image taken by low energy X-rays emitted from the X-ray source 12. A high energy image is an image taken with high energy X-rays emitted from the X-ray source 12. The bone density measuring unit 46 generates a difference image by subtracting the generated X-ray images (high energy image, low energy image), and calculates bone density based on the density value of the difference image. The calculated bone density is stored in the storage device 23 and displayed on the display device 25.

  Next, a bone density measurement process executed by the control device 21 of the X-ray image diagnostic apparatus 1 will be described with reference to FIGS. FIG. 3 is a flowchart showing the overall flow of the bone density measurement process.

  When the BMD mode (bone density imaging mode) is selected by an operator's operation and an instruction to start an examination is given, the control device 21 first transmits an instruction to start a fluoroscopic image acquisition operation to the imaging device 10. The imaging apparatus 10 irradiates the subject 3 with fluoroscopic X-rays from the X-ray source 12, detects X-rays transmitted through the subject 3 with the X-ray receiver 16, and sends the X-rays to the operating device 20. The image processing device 22 of the operating device 20 sequentially generates a fluoroscopic image based on the acquired transmitted X-ray dose and displays it on the display device 25 (step S101).

  While displaying the fluoroscopic image, the control device 21 receives a positioning operation of the subject 3 (step S102). The positioning operation by the operator is performed via the input device 24 or an operation unit (not shown) provided on the photographing device 10 side while referring to the fluoroscopic image 50 displayed on the display device 25. The position of the bed and the position of the video system (distance between the X-ray source 12 and the bed 15) are adjusted by the positioning operation.

  When the start of the confirmation process is instructed by a predetermined operation such as a pressing operation of the start button (step S103; Yes), the control device 21 starts the confirmation process of the bone density measurement region (step S104). In the confirmation processing in step S104, detection of the measurement region (femoral head 57, small trochanter 55, major trochanter 54, neck 56) from the fluoroscopic image 50, and whether or not the detected measurement region fits in the X-ray irradiation field. It is determined whether the cervical ROI 62 contains any bone other than the cervical portion 56 such as the sciatic bone. Details of the confirmation process will be described later.

  When the confirmation processing in step S104 is completed and the photographing button is pressed (step S105; Yes), the control device 21 adjusts the X-ray diaphragm 13 based on the measurement ROI 61 set in the confirmation processing (step S106). The position of the video system (X-ray source 12 and X-ray receiver 16) is moved to the X-ray irradiation start position (step S107), and the irradiation of the bone density measurement X-ray is started (step S108).

  The imaging apparatus 10 irradiates the measurement ROI 61 of the subject 3 with high energy X-rays. Further, the measurement ROI 61 of the subject 3 is irradiated with low energy X-rays. The image processing device 22 generates a high energy image obtained by irradiating the subject 3 with high energy X-rays and a low energy image obtained by irradiating the subject 3 with low energy X-rays. Are generated (step S109). The control device 21 calculates the bone density based on the density value of the difference image acquired in step S110. The control device 21 displays the calculated bone density on the display device 25 (step S110), and ends a series of bone density measurement processes.

  With reference to FIGS. 4 to 8, the measurement region confirmation processing in step S104 will be described.

  As shown in the flowchart of FIG. 4, the control device 21 (confirmation processing unit 43) first extracts the aperture region 51, the direct X-ray region 52, and the subject region 53 from the fluoroscopic image 50 (step S201; see FIG. 5). Each of the regions 51, 52, and 53 can be extracted based on density information and edge information of the fluoroscopic image 50, presence / absence and arrangement of a straight line portion, and the like.

  Next, the control device 21 (confirmation processing unit 43) detects the greater trochanter 54, the lesser trochanter 55, the neck 56, and the femoral head 57 in the proximal femur from the density information and edge information of the subject region 53. (Steps S202 to S205).

  FIG. 6A is a diagram for explaining the detection of the greater trochanter 54 and the smaller trochanter 55. The control device 21 extracts the greater trochanter 54 based on the edge information on the outside of the fluoroscopic image 50 (the solid line portion on the left side of the fluoroscopic image 50) (step S202), and the edge on the inside (the solid line portion on the right side of the fluoroscopic image 50). The little trochanter 55 is extracted by calculating the information and the protruding portion (step S203). The perspective image 50 in FIG. 6A represents the right foot, but in the case of the left foot, the outer and inner edges are depicted opposite to FIG. 6A.

  Further, as shown in FIG. 6B, a small region is set based on a small trochanter region inside the femur (an image is divided into small regions), and a cervical region is detected from density information and edge information. (Step S204). That is, a bone region is extracted from the density information and the edge information, and the axis that is the shortest in the vertical direction is set as a candidate for the neck 56, and it is determined whether the edge of the neck 56 is based on the edge length and inclination of the peripheral part. If it is determined that the neck portion 56, the end point of the corresponding edge is connected to be a neck region.

  Further, a profile is created in the X-axis direction from the edge on the outer side of the femur, and if it is below the threshold value, it is determined as an edge candidate. Compared with the width of the femur, if it is within the threshold, the femur edge is determined. That is, the femoral head 57 is detected (step S205; FIG. 6C).

  The control device 21 sets margins in the neck region, the greater trochanter side, and the upper region detected by the processing in steps S202 to S205, respectively, and sets it as the measurement ROI 61. Examples of margins are: left: 10 mm outside the greater trochanter 54, 30 mm above the greater trochanter 54, 30 mm to the right of the cervical center of gravity, 30 mm below the intersection of the cervical axis and the left side of the ROI. For example, a small trochanter 55 to 30 mm) is suitable, but the present invention is not limited to this and may be any value. Further, a predetermined margin is provided from the side of the neck 56 detected in step S204, and the neck ROI 62 is set. Then, the control device 21 guides and displays the measurement ROI 61 and the cervical ROI 62 on the fluoroscopic image 50 (step S206).

  FIG. 7 shows an example of the measurement ROI 61 and the cervical ROI 62 that are displayed superimposed on the fluoroscopic image 50. In the example of FIG. 7, a diaphysis tilt line 63 indicating the tilt of the diaphysis is further displayed as a guide on the fluoroscopic image 50. The shaft tilt line 63 will be described in the second embodiment.

  The control device 21 sets the upper end or lower end of the measurement ROI 61 as the X-ray irradiation start position, and sets the other end in the vertical direction as the X-ray irradiation end position. Also, the left and right edges of the measurement ROI 61 are set as the X-ray aperture position.

  Next, the control device 21 (confirmation processing unit 43) determines whether or not all the detected measurement ROIs 61 are included in the X-ray irradiation field (step S207). When the measurement ROI 61 is not included in the X-ray irradiation field (step S207; No), an error notification is performed (step S208). As the error notification, the display color of the displayed measurement ROI 61 is changed, or the error notification screen 71 shown in FIG. 8A is displayed. For example, a message “Measurement ROI is missing” or the like is displayed on the error notification screen 71. In addition, an “OK” button 71 a is displayed on the error notification screen 71. When the “OK” button 71a is pressed, the operation returns to the positioning operation in step S102.

  Next, the control device 21 (confirmation processing unit 43) determines whether or not other bones such as a sciatic bone are contained in the neck ROI 62 (step S209). When another bone is contained in the cervical ROI 62 (step S209; No), an error notification is performed (step S210). As the error notification, the display color of the displayed cervical ROI 62 is changed, or the error notification screen 72 shown in FIG. 8B is displayed. On the error notification screen 72, for example, a message “sciatic bone is included in the neck ROI” is displayed. In addition, an “OK” button 72 a is displayed on the error notification screen 72. When the “OK” button 72a is pressed, the operation returns to the positioning operation in step S102.

  In step S207, it is determined that all the measurement ROIs 61 are within the X-ray irradiation field (step S207; Yes). In step S209, it is determined that the cervical ROI 62 is only the cervical part 56 and does not include other bones (step S209). ; Yes), the control device 21 enters the standby state (step S211) of the operation of pressing the photographing button (instruction to start X-ray irradiation) on the display device 25, and proceeds to step S105 in FIG.

  As described above, in the X-ray image diagnostic apparatus 1 capable of acquiring the fluoroscopic image 50, the control device 21 receives a positioning operation using the fluoroscopic image 50 before the bone density imaging. Further, the control device 21 detects a bone density measurement measurement region from the fluoroscopic image 50, checks whether or not the detected measurement region is appropriate as the bone density measurement region, and notifies the user if it is not appropriate. Thereafter, bone density imaging is performed on the measurement region set by the positioning operation. Thereby, the operator can easily perform the positioning operation of the subject with reference to the fluoroscopic image 50, and can easily know whether the positioning of the measurement region is correct before the bone density imaging.

[Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to FIGS. The X-ray diagnostic imaging apparatus 1 determines whether or not the inclination of the diaphysis is within a predetermined allowable range in the measurement region confirmation process (step S104 in FIG. 3), and when the inclination is outside the predetermined allowable range. Notify that.

  FIG. 9 is a flowchart for explaining the flow of the measurement region confirmation processing in the second embodiment. Note that this confirmation processing is performed before the start of bone density imaging as in the first embodiment (see FIG. 3). Further, it is desirable to perform the confirmation process shown in FIG. 9 in addition to the confirmation process (see FIG. 4) of the first embodiment.

  In the confirmation processing shown in FIG. 9, the control device 21 (confirmation processing unit 43) first extracts the aperture region 51, the direct X-ray region 52, and the subject region 53 from the fluoroscopic image 50 (step S301; see FIG. 5). Next, the control device 21 detects the diaphysis from the fluoroscopic image 40 based on the density information and edge information of the subject region 53 (step S302), and calculates the inclination of the detected diaphysis (step S303).

  As shown in FIG. 10, the inclination G of the diaphysis is calculated based on the inclination Gl of the left side (left edge) and the inclination Gr of the right side (right edge) of the femur. In addition, the control device 21 (guide display unit 42) displays a diaphysis inclination line 63, which is a line indicating the inclination G of the diaphysis, so as to overlap the diaphysis of the femur (step S304). The reference for the inclination is, for example, 0 ° in the vertical direction (up and down direction of the fluoroscopic image 50) with respect to the upper and lower ends of the X-ray receiver 16.

  In step S304, the control device 21 may further display the value of the diaphysis tilt angle. FIG. 11A shows an example of a diaphysis tilt line 63 and a diaphysis tilt angle 64 that are displayed superimposed on the fluoroscopic image 50. In the example of FIG. 11A, the diaphysis tilt angle is displayed as “2 °”. Thereby, it can be confirmed that the entire diaphysis is tilted by about 2 ° with respect to the vertical direction of the fluoroscopic image 50.

  Further, in step S303 to step S304, as shown in FIG. 11B, the control device 21 (confirmation processing unit 43) causes the cervical axis 65 passing through the center of gravity 66 of the cervical region and the diaphysis inclination indicating the inclination of the diaphyseal part. An angle between the line 63 (diaphysis-cervical angle 67) is calculated, and the calculated diaphyseal-cervical angle value 67, the cervical axis 65, and the diaphysis tilt line 63 are superimposed on the fluoroscopic image 50 and displayed. Also good.

  The control device 21 determines whether or not the diaphysis is tilted (step S305). That is, it is determined whether or not the inclination angle of the diaphyseal part (or diaphyseal-cervical part angle) calculated in step S303 is within a predetermined allowable range, and the inclination is out of the predetermined allowable range (step S305; Yes). Performs error notification (step S306). The allowable range of the diaphysis tilt angle is, for example, within about 5 ° from the reference (vertical direction of the fluoroscopic image 50).

  For the error notification, for example, the display color of the displayed shaft inclination line 63 and the angles 64 and 67 is changed, or the error notification screen 73 shown in FIG. 12 is displayed. On the error notification screen 73, a message such as “the femoral shaft is tilted with respect to the fluoroscopic screen” is displayed. In addition, an “OK” button 73 a is displayed on the error notification screen 73. When the “OK” button 73a is pressed, the operation returns to the positioning operation in step S102 of FIG.

  When it is determined in step S305 that the tilt of the diaphysis is within the predetermined allowable range (step S305; No), the control device 21 waits for an operation of pressing an imaging button (an instruction to start X-ray irradiation) on the display device 25 ( Step S307). The process proceeds to step S105 in FIG. The process proceeds to step S105 in FIG.

  Note that the confirmation process of the second embodiment is desirably performed together with the confirmation process of the first embodiment. That is, in the measurement region confirmation process in step S104 of FIG. 3, in addition to the confirmation process of the diaphysis inclination in steps S301 to S306, the measurement region confirmation and the cervical ROI 62 described in the first embodiment are confirmed. It is desirable to perform (Step S202 to Step S209 in FIG. 4).

[Third Embodiment]
Next, a third embodiment of the present invention will be described with reference to FIGS. In the third embodiment, the X-ray diagnostic imaging apparatus 1 performs alignment (setting of measurement ROI 61 and the like) using information recorded at the time of past measurement for a patient with a history of bone density measurement in the past. Make it possible.

The flowchart in FIG. 13 is a flowchart showing the flow of bone density measurement processing in the third embodiment.
When the BMD mode is selected, the control device 21 receives patient information input (step S501). Patient information is patient identification information, such as an examination ticket number, name, and contact information. When patient information is input from the input device 24, the control device 21 determines whether or not measurement information (measurement history) corresponding to the input patient information is stored in the storage device 23 (step S502). When the measurement information is not stored in the storage device 23, that is, in the first bone density measurement, the process proceeds to step S506.

  The processing from step S506 to step S510 is the same bone density measurement processing procedure as that in the first or second embodiment. That is, the control device 21 accepts a positioning operation using the fluoroscopic image 50 at the time of the first measurement (step S506) as in the first or second embodiment, and presses the start button (step S507). A confirmation process is performed (step S508). In the confirmation processing in step S508, the confirmation processing in FIG. 4 or the confirmation processing in FIG. 9 is performed. The control device 21 detects a measurement region including the greater trochanter 54, the lesser trochanter 55, the neck 56, and the femoral head 57 from the fluoroscopic image 50, and determines whether these are within the X-ray irradiation field. In addition, the neck ROI 62 is set, and it is determined whether or not bones other than the neck 56 are included in the neck ROI 62. Further, the inclination of the diaphysis is detected, and the diaphysis inclination line is displayed, and it is determined whether the inclination is within a predetermined range. When the measurement region does not fit in the X-ray irradiation field, when the bone other than the neck 56 is included in the neck ROI 62, or when the inclination of the diaphysis exceeds a predetermined allowable range, an error notification is performed.

  When the alignment is properly performed, the confirmation process is finished. Thereafter, when the photographing button is pressed by the operator (step S509; Yes), the control device 21 executes a bone density measurement process (step S510). The bone density measurement process in step S510 is the process in steps S106 to S110 in FIG.

  That is, the control device 21 adjusts the opening width of the X-ray diaphragm 13 based on the measurement ROI 61 set in the confirmation process (Step S106), and sets the position of the video system (X-ray source 12 and X-ray receiver 16) to X. It moves to the irradiation start position (step S107), and starts irradiation of bone density measurement X-rays (step S108). The imaging apparatus 10 irradiates the measurement ROI 61 of the subject 3 with high energy X-rays. Further, the measurement ROI 61 of the subject 3 is irradiated with low energy X-rays. The image processing device 22 generates a high energy image obtained by irradiating the subject 3 with high energy X-rays and a low energy image obtained by irradiating the subject 3 with low energy X-rays. Are generated (step S109). The control device 21 detects the lumbar region from the edge image of the difference image acquired in step S110, and calculates the bone density based on the detected pixel value of the lumbar region. The control device 21 displays the calculated bone density on the display device 25 (step S110).

  When the bone density measurement in step S510 is completed, the control device 21 stores the measurement information in association with the patient information in the storage device 23 (step S111). The measurement information stored here includes at least the measurement region (measurement ROI 61) set in the confirmation process (step S508), the X-ray irradiation start position, the difference image generated in the bone density measurement process in step S510, and the like.

  When the measurement information is stored, the initial bone density measurement process for the patient ends.

  In the second and subsequent bone density measurements, when patient information is input in step S501, measurement information related to the input patient information is retrieved from the storage device 23 (step S502). When the measurement information related to the input patient information is stored in the storage device 23 (step S502; Yes), the control device 21 reads the measurement information in the previous measurement (step S503). The measurement information to be read is information such as a difference image generated at the previous measurement, a measurement ROI 61, and an X-ray irradiation start position.

  The control device 21 starts capturing the fluoroscopic image 50, and displays the fluoroscopic image 50 currently being acquired on the display device 25 (step S504).

  Furthermore, the control device 21 is currently acquiring the previous difference image (hereinafter referred to as the previous image 82), the previous measurement ROI 81, the previous X-ray irradiation start position, and the like based on the previous measurement information read in step S503. Are superimposed on the fluoroscopic image 50 (step S505).

  FIG. 14 is an example in which the previous image 82 and the previous measurement ROI 81 are displayed on the fluoroscopic image 50 currently being acquired. For example, as shown by the dotted line in FIG. 14, the previous image 82 displays only the edge information extracted from the previous image 82 on the current fluoroscopic image 50, or makes the previous image 82 translucent and overlays the current fluoroscopic image. It is desirable that it is displayed so as to be easily distinguishable from the fluoroscopic image 50 being acquired, such as by displaying.

  The operator performs a positioning operation while visually confirming the previous measurement information (step S506). By setting the same measurement ROI 61 as the previous time, it is easy to observe the bone density over time.

  Thereafter, the measurement region confirmation process is executed by pressing the start button (step S508). Since alignment is performed based on the previous measurement information, an appropriate measurement area can be set more quickly than in the first measurement.

  Thereafter, a bone density measurement process is started by pressing the photographing button (step S509), and a difference image is generated and a bone density is calculated (step S510). The generated difference image and information on the calculated bone density are stored in the storage device 23 in association with the patient information together with the measurement ROI 61 and the like set in the confirmation processing in step S508 (step S511). The stored measurement information is referred to at the next bone density measurement.

  As described above, according to the X-ray diagnostic imaging apparatus 1 of the third embodiment, for a patient with a history of measurement, the previous measurement information (the previous image, the previously set measurement ROI, X-ray irradiation start) Since the position and the like are superimposed on the fluoroscopic image 50 being acquired at this time, the alignment becomes easy. In addition, since the same region as the previously set measurement ROI 81 can be easily set as the current measurement ROI 61, it is possible to accurately observe the bone density over time.

  The preferred embodiments of the X-ray image diagnostic apparatus and the like according to the present invention have been described above with reference to the accompanying drawings, but the present invention is not limited to such examples. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the technical idea disclosed in the present application, and these are naturally within the technical scope of the present invention. Is done.

1 X-ray diagnostic imaging device 10 Imaging device 12 X-ray source 13・ X-ray diaphragm 15... Bed 16... X-ray receiver 20. Control device 22 Image processing device 23 Storage device 24 Input device 25 Display device 3... Subject 41... Measurement area detector 42... Guide display unit 43. -Confirmation processing unit 44 ... Notification unit 45 ... Measurement area X-ray irradiation start position setting unit 46 ... Bone density measurement unit 50 ············································· Area 52 ... Direct X-ray area 53 ... Subject area 54 ... Greater trochanter 55 ... Little trochanter 56 ... Neck 57 ... Femoral head 61 ... Measurement ROI
62 ・ ・ ・ ・ ・ ・ ・ ・ ・ Neck ROI
63 ... ... Skeletal tilt lines 71, 72, 73 ... Error notification screen 81 ... ... Previous measurement ROI
82 .... Previous image

Claims (10)

An X-ray source that irradiates a subject with a plurality of X-rays having different energy peaks;
An X-ray receiver that is disposed opposite to the X-ray source and detects transmitted X-rays transmitted through the subject;
An image processing unit that generates each X-ray image corresponding to a fluoroscopic image or an energy peak based on the transmitted X-ray;
A positioning operation unit for displaying the fluoroscopic image and receiving a positioning operation;
A measurement region detection unit for detecting a measurement region of bone density measurement from the fluoroscopic image;
A confirmation processing unit for confirming whether or not the detected measurement region is appropriate as a bone density measurement region;
A notification unit for notifying a result of confirmation by the confirmation processing unit;
A bone density calculation unit that generates a difference image from each X-ray image obtained by irradiating the measurement region with two types of high and low X-rays having different energy peaks, and calculates a bone density based on the generated difference image; ,
An X-ray diagnostic imaging apparatus comprising: The measurement area includes the femoral head, the greater trochanter, the lesser trochanter, and the femoral neck.
The confirmation processing unit determines whether or not the measurement region fits in an X-ray irradiation field,
The X-ray image diagnosis apparatus according to claim 1, wherein the notification unit notifies that when the measurement region does not fit in the X-ray irradiation field.   The X-ray image diagnostic apparatus according to claim 1, further comprising a guide display unit that displays the measurement region detected by the measurement region detection unit so as to overlap the fluoroscopic image. The confirmation processing unit extracts a femoral neck from the measurement region, sets a region of interest so as to surround the extracted femoral neck, and includes a bone other than the femoral neck in the region of interest. Determine whether or not
The X-ray diagnostic imaging apparatus according to claim 1, wherein the notification unit notifies that when a bone other than a femoral neck is included in the region of interest. The confirmation processing unit calculates the inclination of the femoral shaft, determines whether or not the calculated inclination is within a predetermined allowable range,
The X-ray diagnostic imaging apparatus according to claim 1, wherein the notification unit notifies that when the inclination is out of a predetermined allowable range.   The X-ray diagnostic imaging apparatus according to claim 5, wherein the confirmation processing unit displays a line indicating the inclination of the femoral shaft and an angle of the calculated inclination so as to overlap the fluoroscopic image.   The confirmation processing unit further calculates an angle between a neck axis passing through the center of gravity of the femoral neck region and a line indicating a tilt of the femoral shaft, and calculates the calculated angle, the neck axis, and the The X-ray image diagnosis apparatus according to claim 5, wherein a line indicating the inclination of the femoral shaft is displayed so as to overlap the fluoroscopic image. A start position setting unit for setting an X-ray irradiation start position for measuring bone density;
A storage unit that stores the measurement region, the X-ray irradiation start position, and the difference image generated by the bone density calculation unit in association with patient information, and stores it as measurement information;
The X-ray image diagnostic apparatus according to claim 1, further comprising: An input unit for inputting patient information of a patient to be measured;
When the measurement information associated with the input patient information is stored in the storage unit, the measurement region and the X-ray irradiation start position set in the past measurement and the past difference image are read, and the fluoroscopy Last time guide display part to be superimposed on the image,
The X-ray image diagnostic apparatus according to claim 8, further comprising: Based on an X-ray source that irradiates a subject with a plurality of X-rays having different energy peaks, an X-ray receiver that is disposed opposite to the X-ray source and detects transmitted X-rays transmitted through the subject, and the transmitted X-rays An X-ray diagnostic imaging apparatus comprising an image processing unit that generates a fluoroscopic image or each X-ray image according to an energy peak,
The control unit
Displaying the fluoroscopic image and receiving a positioning operation;
Detecting a bone densitometry measurement region from the fluoroscopic image;
Confirming whether the detected measurement area is appropriate as the measurement area of bone density;
Displaying the result of the confirmation;
Generating a difference image from each X-ray image obtained by irradiating the measurement region with two types of high and low X-rays having different energy peaks, and calculating a bone density based on the generated difference image;
The bone density measuring method characterized by performing the process containing these.

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