JP2009189635A - X-ray ct apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an X-ray CT apparatus capable of relieving the stress of a subject in an examination of the subject by the X-ray CT apparatus, capable of eliminating the complication of the examination by omitting a technologist's instructions to breathe, and preventing deterioration of the image quality of an X-ray CT image caused by the failure in stopping breathing. <P>SOLUTION: In the X-ray CT apparatus, a pre-tone output position is set at a location in the rear of the position when the tomography is started on a tomography range setting screen, and a post-tone output position is set between the position when the tomography is terminated and the pre-tone output position. The instructions to stop breathing are executed when the pre-tone output position is detected, and further, the instructions to release the stop of breathing are executed when the post-tone output position is detected. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a technique for an X-ray CT apparatus capable of achieving breath holding and breathing timing required for a subject.

  An X-ray CT (Computed Tomography: X-ray computed tomography) apparatus exposes X-rays to a subject, detects X-rays transmitted through the subject and attenuated, and obtains the attenuation rate of the detected X-rays An image such as a tomographic image is generated by collecting and reconstructing. In this image generation process, before starting imaging within the subject, a scan plan is determined in which the operator determines in advance which range of the subject is to be examined. In the scan plan, the imaging range is determined by determining the imaging start position and the imaging end position of the examination site in the subject by the operator (see Patent Document 1).

  In the X-ray CT apparatus, the subject is imaged based on this scan plan, but some of the examination sites that may need to be examined in the subject include the heart and lungs in the image reconstruction range. There is a range with no body movement and a range without body movement. Data required to reconstruct an image differs between a range with body movement and a range without body movement. This body movement is a movement accompanying the activity of the body tissue of the subject.

  When photographing a range involving body movement, it is necessary to suppress body movement of the subject so as not to hinder image generation. For example, when examining the chest, it is necessary to temporarily hold the patient's breath to suppress movement of the heart, lungs, and the like.

  Conventionally, there has been an X-ray CT apparatus that displays an instruction to hold a breath on the subject or outputs it by voice. In such an X-ray CT apparatus, in conjunction with the start of imaging in the scan plan, for example, a display or a voice saying “Please hold your breath” is output, and in synchronization with the end of imaging in the scan plan, Please display "or a voice message (see paragraphs 0020 and 0021 of Patent Document 2).

JP 2006-167346 A Japanese Patent Laid-Open No. 2006-314779

  In recent years, improvement in the performance of the X-ray CT apparatus has made it possible to perform imaging of a plurality of parts of a subject at one time. For example, an examination such as searching for a diseased part from the whole body of a subject can be performed. It was. As a result, a wider imaging range is planned in the scan plan as compared with the conventional case.

  In this regard, the X-ray CT apparatus described in Patent Document 2 is configured to display “breath holding start” from the imaging start position and to display “breath holding released” at the imaging end position. Therefore, when a wide imaging region is planned as in the case of examining a plurality of parts, such an X-ray CT apparatus forces the subject to hold his / her breath for a long time, which is large for the subject. It becomes a burden. Depending on the condition of the subject, it may be difficult to hold the breath for a long time. As a result, the subject may fail to hold the breath at the examination site where the body movement is to be suppressed, and the image quality of the generated X-ray CT image is reduced. It was also a cause of worsening.

  In response to this, when the operator reaches the region where the influence of the body movement is small while viewing the imaging position on the real-time display image or the imaging preparation image (scanogram image), Sending breathing instructions. However, it is very complicated for an operator who examines a subject with an X-ray CT apparatus to observe the state of the subject and simultaneously check a photographing position on a real-time image or a photographing preparation image and give a breathing instruction. . Also, depending on the operator, the timing of breathing instructions may vary, which may cause the image quality of the generated X-ray CT image to deteriorate.

  The present invention has been made in view of the above problems, and its purpose is to reduce the burden on the subject in the examination of the subject by the X-ray CT apparatus and omit the breathing instruction by the operator. An object of the present invention is to provide an X-ray CT apparatus capable of eliminating complexity and further preventing a situation where the image quality of an X-ray CT image is deteriorated due to a failure to hold the breath.

  In order to solve the above-described problems, the present invention provides a gantry device for imaging a subject, range setting means for setting an imaging range in the gantry device in advance, and a couch device provided with a top plate on which the subject is lying An X-ray CT apparatus for imaging the imaging range while relatively moving the gantry device and the top plate in the body axis direction of the subject, An instruction means for instructing to release the breath hold, a first point after the photographing start position of the photographing range set in advance by the range setting means, and a photographing end position and the first point A timing setting means for setting a second point in between, and after the start of photographing, the instruction means is instructed to hold the breath when the first point is detected as the top plate moves. And detect the second point. Is an X-ray CT apparatus characterized by and a control means for executing the instruction of the release the breath hold on the instruction means when.

  According to the present invention, when the first point after the shooting start position is set, the second point is set between the shooting end position and the first point, and the first point is detected The instruction means is configured to execute a breath holding instruction, and when the arrival of the second point is detected, the instruction means is configured to execute a breath holding release instruction. Accordingly, it is possible to achieve the timing of breath holding and release of breath holding required for the subject, reduce the burden on the subject in the examination of the subject by the X-ray CT apparatus, and omit the breathing instruction by the examiner. Thus, it is possible to eliminate the complexity of the inspection and to prevent a situation in which the image quality of the X-ray CT image is deteriorated due to failure to hold the breath.

  Hereinafter, an example of an embodiment of the present invention will be described with reference to FIGS.

(overall structure)
The configuration of the X-ray CT apparatus according to the embodiment of the present invention will be described with reference to FIG. FIG. 1 is a schematic block diagram showing a schematic configuration of an X-ray CT apparatus according to an embodiment of the present invention.

  As shown in FIG. 1, the X-ray CT apparatus according to this embodiment drives the bed apparatus 130 on which the subject is placed through the operation of the console unit 120 by the operator, thereby Carry in / out the subject. The X-ray CT apparatus collects in-vivo information of the subject carried in by the bed apparatus 130. In the X-ray CT apparatus according to the first embodiment, the imaging range is set on the scanogram by the operator. Further, the X-ray CT apparatus further sets a sound output position within the set imaging range, thereby executing either a breath holding instruction or a breath holding release instruction at the set position. In the X-ray CT apparatus according to the second embodiment, the contrast agent inflow in the subject is detected by pre-scanning, and a breath holding instruction is executed when a predetermined CT value is exceeded. Hereinafter, the configuration of each part of the X-ray CT apparatus common to the first embodiment and the second embodiment will be described.

<Mounting device>
The gantry device 110 has a cylindrical imaging region, and a subject is accommodated in the imaging region. In this imaging region, a rotating gantry 111 is provided, and an X-ray tube 112 and an X-ray detector 113 are arranged to face the rotating gantry 111. At the time of imaging of the subject, the X-ray tube 112 and the X-ray detector 113 are rotated in the rotating gantry 111 while being opposed to each other by the gantry driving unit 114.

  Further, in the gantry device 110, the high voltage generation unit 115 supplies current to the X-ray tube 112 to heat the filament and applies high voltage to generate X-rays in the X-ray tube 112. The generated X-rays are narrowed down into a fan beam shape or a cone beam shape by the collimator 116 being adjusted by the diaphragm drive unit 117.

  The aperture driving unit 117 narrows the aperture of the collimator 116 during pre-scanning for detecting the inflow of contrast medium. The aperture of the collimator 116 is widened at the time of helical scanning for capturing an image of the subject.

  The X-ray detector 113 detects X-rays that have passed through the subject by the X-ray detection element and passed through a collimator (not shown) on the detector side. The detected X-ray is transmitted as a current signal to a data acquisition unit 118 (DAS: Data Acquisition System). The data acquisition unit 118 amplifies the output current from the X-ray detector, and then converts it into digital data for projection data. Are output to the console unit 120.

<Console section>
The console unit 120 includes a control unit that controls the entire X-ray CT apparatus, an input unit 128 (including a microphone; including a microphone) related to the overall operation of the X-ray CT apparatus, and a display unit 129 that displays various images. . The main control unit 121 in the console unit 120 performs integrated control of each control unit of the X-ray CT apparatus, such as the scan control unit 122, the image generation unit 123, and the instruction unit 150. The scan control unit 122 controls the gantry driving unit 114, the high voltage generation unit 115, and the aperture driving unit 117 of the gantry device 110.

  Further, the scan control unit 122 controls a bed driving unit 131 of a bed device 130 described later to move the top board 133. In addition, the scan control unit 122 moves the table top 133 at the first movement speed until the range where the body movement of the subject lying on the table top 133 is likely to occur reaches the X-ray exposure region of the gantry device 110. The bed driving unit 131 is controlled so that the top 133 is moved to the second movement speed while the range in which the movement is likely to occur passes through the X-ray exposure region. However, the bed driving unit 131 can be driven so that the first movement speed and the second movement speed are the same. The first moving speed corresponds to an example of “first speed” in the present invention, and the second moving speed corresponds to an example of “second speed” in the present invention.

  The image generation unit 123 corrects the projection data received from the data collection unit 118 by the preprocessing unit 124, stores the projection data in the projection data storage unit 125, and performs reconstruction processing by the reconstruction unit 126. Do. When the reconstruction process is performed, the image processing unit 127 performs image processing to generate a scanogram (scout image) and tomographic image data. An X-ray CT image is generated from the tomographic image data.

  Note that a scanogram is a radiographic image captured at a single X-ray projection angle, and is an image for designating a range to be imaged when capturing a tomographic image of a subject. The scanogram corresponds to an example of the “photographing preparation image” in the present invention. The scanogram is generated as follows, for example.

  In order to generate a scanogram, the scan control unit 122 in the X-ray CT apparatus does not rotate the X-ray tube 112 and the X-ray detector 113 in the rotating gantry 111, and the subject is fixed at a single projection angle. Perform the inspection. That is, while the X-ray tube 112 and the X-ray detector 113 are fixed at a first angle (for example, 0 ° (directly above the subject)), X-rays are emitted and the top 133 is opposite to the subject. Move in the direction. In this way, the projection data is detected, and the image generation unit 123 generates a first scanogram (see FIG. 2).

  When not only the first scanogram but also a scanogram at another projection angle is required, for example, a scanogram in the thickness direction as well as the body surface side may be required. In this case, after the first scanogram generation step, the X-ray CT apparatus sets the X-ray tube 112 and the X-ray detector 113 to a second angle different from the first angle (for example, 90 ° (right side of the subject)). And the projection data is detected in the same manner to generate a second scanogram. In this way, the scanogram generation operation is repeated a plurality of times, and a scanogram used to determine the imaging range in tomographic image imaging is generated.

  Further, the scanogram and the X-ray CT image generated by the image processing unit 127 are displayed on the display unit 129, for example, by the main control unit 121, and are also stored in a storage unit (not shown) in the main control unit 121.

  Further, the biological data of the subject is output from the biological signal detection device 140 shown in FIG. That is, an image may be reconstructed in synchronism with a biological signal in a range with body movement such as a chest, and the biological signal and projection data are associated with each other in a time series in the order in which each data element is generated. Stored in the storage unit 125.

<Couch device>
The couch device 130 receives a drive signal from the scan control unit 122 of the console unit 120 in accordance with the operation of the operator. In other words, the couch device 130 drives the couch driving unit 131 to move the couchtop 133 provided on the fixed base 132 on which the subject is placed into the gantry device 110. The couch device 130 is moved so as to return the top plate 133 from the gantry device 110 side to the couch device 130 side. In the X-ray CT apparatus, since the inspection is performed by changing the relative positions of the top plate 133 of the gantry device 110 and the bed device 130, for example, the top plate 133 is fixed and the gantry device 110 is fixed to the top plate 133. It is also possible to move so as to be close to or away from each other.

<Indicator>
The instruction unit 150 outputs sound such as a breath holding instruction to the subject while the subject is being examined by the gantry device 110. That is, in response to a control signal from the main control unit 121 of the console unit 120, the audio control unit 152 outputs audio from the output unit 151 (for example, a speaker) at a predetermined timing. Details of the audio output timing control will be described later. The output unit 151 also outputs a sound even when an operator or the like directly gives an instruction or the like using the input unit 128. The instruction unit 150 corresponds to an example of “instruction means” and “timing setting means” in the present invention.

  In addition, when outputting the voice of breath holding instruction, the voice control unit 152 causes the output unit 151 to output a voice “Please hold your breath”, for example. In addition, when outputting a voice for releasing breath hold, that is, permitting breathing, the voice control unit 152 causes the output unit 151 to output a voice “please do it comfortably” or “please breathe”, for example.

[First embodiment]
Next, the configuration of the X-ray CT apparatus according to the first embodiment of the present invention will be described with reference to FIG. 1 and FIG. FIG. 2 is a schematic diagram showing a shooting range / audio output position setting screen according to the embodiment of the present invention.

(Shooting range setting)
The setting of the imaging range of the X-ray CT apparatus in the first embodiment will be described. In the X-ray CT apparatus according to the first embodiment, a format for creating an imaging range setting screen is stored in a storage unit (not shown) in the main control unit 121. The X-ray CT apparatus generates an imaging range setting screen based on this format and the generated scanogram in the main control unit 121. The generated shooting range setting screen is displayed on the display unit 129.

  In addition, after the shooting range setting screen is displayed on the display unit 129, the operator can make a scan plan by setting the shooting range with the input unit 128 (for example, a pointing device such as a mouse) (FIG. 2). reference). That is, the operator sets an imaging range (Px to Py in FIG. 2) such as a rectangle (or a circle or a polygon) by the input unit 128 on the imaging range setting screen displayed on the display unit 129 and generated based on the scanogram. When set, the main control unit 121 displays the set imaging range on the display unit 129 and causes the storage unit (not shown) to store one end side in the body axis direction as the imaging start position Px and the other end with respect to the one end. Is stored as the photographing end position Py.

  Further, the operator can set a range in which body movement is likely to occur using the input unit 128. By setting the range in which body movement is likely to occur, the scan control unit 122 controls the driving of the bed driving unit 131 and stores the time point when the moving speed of the top board 133 is changed.

  Furthermore, when the range is set, the image generation unit 123 causes the start point P1 or P3 (see FIG. 2) of the range in which the top plate 133 moves and easily causes body movement to reach the imaging region of the gantry device 110. Then, switching is performed so that the image is reconstructed in synchronization with the biological signal. That is, the image generation unit 123 causes the projection data storage unit 125 to store the projection data processed by the preprocessing unit 124. Further, the image generation unit 123 receives the biological signal output from the biological signal detection device 140 and causes the reconstruction unit 126 to reconstruct the projection data stored in the projection data storage unit 125 in synchronization with the biological signal.

  It should be noted that a plurality of ranges within which the body movement is likely to occur can be designated within the imaging range (for example, P1 to P2 and P3 to P4 in FIG. 2).

The range in which body motion is likely to occur is a range of the chest including the heart and lungs as shown in FIG. 2, and is determined by the operator or the like based on a scan range setting screen based on a scanogram.
When the range in which body movement is likely to occur is not set, the audio output position setting described below is not performed, and the instruction unit 150 does not execute audio output.

(Audio output position setting)
Next, setting of the audio output position of the audio control unit 152 according to the first embodiment will be described with reference to FIG.

  When the image generation unit 123 generates a scanogram and an imaging range and a range in which body movement is likely to occur are set on the imaging range setting screen, for example, a breath-holding instruction voice (hereinafter simply referred to as “ The timing of the output of the “previous voice”) and the output of the breath-hold release instruction voice (hereinafter simply referred to as “rear voice”) are set.

  When the shooting ranges Px to Py and the ranges in which body movement is likely to occur (for example, P1 to P2 and P3 to P4 in FIG. 2) are set on the shooting range setting screen, the main control unit 121 performs voice control on data in these ranges. To the unit 152. From this data, the sound control unit 152 is likely to cause body movements as follows: the photographing start position Px, the photographing end position Py of the photographing range on the top board 133, the starting point positions P1 and P3 of the range in which body movement is likely to occur. The positions of the end points P2 and P4 of the range are obtained. Note that the start point is one end on the imaging start position side in the range where the set body movement is likely to occur, and the end point is the other end relative to the one end in the set range where the body movement is likely to occur.

  That is, the voice control unit 152 receives data on the coordinate positions of these points on the shooting range setting screen from the main control unit 121. Upon receiving the coordinate position data, the voice control unit 152 receives the distance from the imaging start position Px to the start position P1 of the range in which body movement is likely to occur (the amount of movement of the top board 133), based on the scale ratio of the scanogram. The distance to the end point position P2 of the range in which body movement is likely to occur is calculated (see FIG. 2).

  After calculating the distance from the shooting start position Px to the positions of the points (P1 to P4), the sound control unit 152 calculates the output positions P5 and P6 of the previous sound. This calculation method is as follows. First, the voice control unit 152 obtains a distance obtained by subtracting the amount of movement of the top board 133 for the time required to complete the output of the previous voice from the distance from Px to P1. Further, the voice control unit 152 sets the position separated by the calculated distance from the shooting start position Px as the output position P5 of the previous voice.

  The time required to complete the output of the previous sound is the time from the start of the output of the previous sound until the subject completes breath holding, which is set in advance based on the rule of thumb. It is stored in a storage unit (not shown) in the voice control unit 152.

  That is, the sound control unit 152 starts outputting the previous sound immediately before the start point P1 of the range in which body movement is likely to occur and reaches the imaging region of the gantry device 110, and before the start point P1 reaches the imaging region, The output position P5 of the previous voice is set so that the voice output is completed. The imaging area is an area surrounded by the rotating gantry 111 of the gantry device 110.

  Further, the sound control unit 152 obtains a distance obtained by subtracting the amount of movement of the top board 133 necessary for the output of the previous sound from the distance from Px to P3, similarly to the setting method of the output position P5 of the previous sound, and further shooting. A position separated from the calculated position Px by the calculated distance is set as a previous audio output position P6. The output positions P5 and P6 of the previous voice correspond to an example of the “first point” in the present invention.

  On the other hand, the voice control unit 152 sets the end points P2 and P4 of the range in which body movement is likely to occur as the output position of the rear voice. The output positions P5 and P6 of the previous sound set in this way are stored in a storage unit (not shown) of the sound control unit 152. The output position P2 of the rear audio corresponds to an example of “second point” in the present invention.

(Audio output control)
Next, the audio output control of the audio control unit 152 according to the first embodiment will be described with reference to FIG.

  When imaging is started based on the imaging range in the scan plan in which the X-ray CT apparatus is set, the voice control unit 152 monitors the movement amount of the top board 133 from the time when the imaging starts. The movement amount of the top board 133 is calculated by the voice control unit 152 based on the elapsed time from the shooting start time and the moving speed of the top board 133.

  The elapsed time is measured after receiving a scan start signal from the scan control unit 122. The elapsed time is measured by time measuring means (not shown) in the main control unit 121 and transmitted to the voice control unit 152 via the main control unit 121. In addition, the voice control unit 152 receives information about the movement speed used for calculating the movement amount from the scan control unit 122.

  When the scan control unit 122 changes the moving speed of the top board 133 from the first moving speed to the second moving speed in a range where body movement is likely to occur in the shooting range, the voice control unit 152 When monitoring the amount of movement, the amount of movement is calculated by distinguishing the first movement speed of the tabletop 133 until the tabletop 133 reaches a range where body movement is likely to occur and the second movement speed after reaching the range. Execute.

  When the movement amount of the top 133 monitored by the sound control unit 152 reaches the distance from the shooting start position Px to the previous sound output position P5, the sound control unit 152 causes the output unit 151 to output the previous sound. . Also, the front voice is output when the movement amount reaches the distance from the shooting start position Px to the front voice output position P6.

  Similarly, when the distance from the imaging start position Px to the end point P2 of the range where body movement is likely to occur is reached, the output unit 151 is made to output the rear voice. Note that the calculation of the movement amount in the voice control unit 152 corresponds to an example of “detection” in the present invention.

(Operation)
Next, the operation of the X-ray CT apparatus in the first embodiment described above will be described with reference to FIG. 3 and 4 are flowcharts showing an outline of the operation of the X-ray CT apparatus according to the first embodiment of the present invention.

(Step 01)
The scan control unit 122 in the X-ray CT apparatus drives the bed driving unit 131 to move the top plate 133 of the bed apparatus 130 on which the subject is lying down to the imaging region of the gantry apparatus 110. In addition, the scan control unit 122 drives the gantry driving unit 114, the high voltage generation unit 115, and the aperture driving unit 117 of the gantry device 110, and emits X-rays to the subject that has moved to the imaging region and detects the X-rays. To do. The detected X-rays become projection data and are subjected to preprocessing and the like. The image generation unit 123 reconstructs the projection data, fixes the X-ray tube 112 and the X-ray detector 113, and captures a scanogram at a single projection angle.

(Step 02)
When the scanogram is generated, the main control unit 121 reads the format of the shooting range setting screen from the storage unit (not shown), and further generates the shooting range setting screen from the format and the generated scanogram (see FIG. 2). Display on the part 129.

(Step 03)
When a shooting range is designated via the input unit 128 by an operator or the like on the shooting range setting screen, the main control unit 121 stores the shooting start position Px and the shooting end position Py in a storage unit (not shown).

(Step 04)
When the photographing ranges Px to Py are set, and a range (for example, P1 to P2 and P3 to P4 in FIG. 2) in which body movement is likely to occur is specified by the operator or the like on the photographing range setting screen. The main control unit 121 stores the start points P1 and P3 and the end points P2 and P4 in a range in which body movement is likely to occur in a storage unit (not shown).

(Step 05)
When ranges that are likely to cause body movement are set, the main control unit 121 transmits data in these ranges to the voice control unit 152. The voice control unit 152 obtains the shooting start position Px, the shooting end position Py, the start positions P1 and P3 of the range where body movement is likely to occur, and the end points P2 and P4 of the range where body movement is likely to occur from this data.

(Step 06)
After calculating the distance from the shooting start position Px to the position of each point (for example, P1 to P4), the voice control unit 152 calculates and sets the output positions P5 and P6 of the previous voice. In addition, the voice control unit 152 sets the end points P2 and P4 in the range where body movement is likely to occur as the output position of the rear voice.

(Step 07)
When the front voices P5 and P6 and the rear voice output positions P2 and P4 are set, the voice control unit 152 stores each position in a storage unit (not shown).

(Step 08)
When shooting is started by the gantry device 110 based on the scan plan, the voice control unit 152 monitors the movement amount of the top board 133 from the shooting start time, and the movement amount from the shooting start position Px to the output position P5 of the previous voice. Judge whether the distance has been reached.

(Step 09)
When the movement amount of the top 133 reaches the distance from the imaging start position Px to the output position P5 of the previous sound (step 08; Yes), the sound control unit 152 causes the output unit 151 to output the previous sound. .

(Step 10)
When the front sound is output from the output unit 151, the sound control unit 152 continues to monitor the movement amount of the top board 133, and the movement amount reaches the distance from the shooting start position Px to the rear sound output position P2. Determine if you did.

(Step 11)
When the amount of movement of the top 133 reaches the distance from the shooting start position Px to the output position P5 of the previous sound (step 10; Yes), the sound control unit 152 causes the output unit 151 to output the previous sound. .

(Function and effect)
The operation and effect of the X-ray CT apparatus according to the present embodiment described above will be described.

  In the X-ray CT apparatus according to the first embodiment, when a range that easily causes body movement is set together with the imaging range on the imaging range setting screen, the start point P1 of the range that easily causes body movement reaches the imaging area of the gantry device 110. The output position P5 of the previous sound is set so that the output of the previous sound is completed immediately before the start point P1 reaches the imaging region, and the output position P5 of the previous sound is completed. The voice control unit 152 causes the output unit 151 to output the previous voice. In addition, the voice control unit 152 sets the end points P2 and P4 of the range in which body movement is likely to occur as the output position of the rear voice, and causes the output unit 151 to output the rear voice based on the setting.

  Therefore, since the X-ray CT apparatus requests the subject to hold his / her breath only when imaging the range in which body movement is likely to occur, the time required to hold his / her breath can be minimized. As a result, the burden on the subject can be reduced. It is possible to avoid the situation that occurs. Furthermore, by reducing the time required to hold the breath to a minimum, it is possible to prevent a situation in which the breath hold occurs for a long time and to prevent a situation in which the image quality of the X-ray CT image is deteriorated due to the failure to hold the breath. Is possible.

  In addition, the X-ray CT apparatus of the present embodiment is configured to execute a breath-hold instruction and release of the breath-hold on the subject only by setting a range in which body movement is likely to occur together with the imaging range on the imaging range setting screen. is there. Therefore, it is possible to avoid variations in timing of breath holding instructions and release instructions by the examiner in the X-ray CT apparatus and occurrence of forgetting breath holding instructions. As a result, the burden on the inspector is reduced and the complexity of the inspection by the X-ray CT apparatus is eliminated. In addition, it is possible to avoid a failure in breath holding due to elimination of variations in timing of the breath holding instruction and the release instruction, and to prevent a situation in which the image quality of the X-ray CT image is deteriorated.

(First modification)
An X-ray CT apparatus according to a first modification of the first embodiment will be described. In the X-ray CT apparatus according to the first embodiment, the movement amount calculated from the movement speed and elapsed time of the top board 133 has reached the distance from the imaging start position to the position immediately before the start point of the range where body movement is likely to occur. Sometimes, a front voice is output, and a rear voice is output when the amount of movement reaches the distance from the imaging start position to the end position of the range where body movement is likely to occur. However, the X-ray CT apparatus according to the present invention may have the following configuration.

  For example, based on the moving speed of the top 133 and the distance from the shooting start position to the position immediately before the start points P1 and P3 in the range where body movement is likely to occur, the time from the shooting start time to the time when the previous sound is output Is calculated. As for the timing of outputting the previous sound, the previous sound is output when the elapsed time reaches the calculated time. Similarly, based on the moving speed and the distance from the shooting start position to the position of the end point of the range where body movement is likely to occur, the time from the shooting start time to the time when the subsequent voice is output is calculated, and the elapsed time is calculated. When the specified time is reached, a later voice is output. The “immediate position” is a position obtained by subtracting the distance obtained by multiplying the output time of the previous sound and the moving speed of the top board from the distance between the shooting start position Px and the start points P1 and P3.

(Second modification)
Next, the setting of the sound output time point of the X-ray CT apparatus in the second modification of the first embodiment will be described. The X-ray CT apparatus according to the first embodiment is configured to calculate the output timings of the front voice and the rear voice on the basis of the positions of the start point and end point of the range in which body movement is likely to occur, which is set on the imaging range setting screen (FIG. 2). It is. However, the X-ray CT apparatus of the present invention may have the following configuration.

  For example, the operator uses the input unit 128 to designate a first point for outputting a breath holding instruction voice on the shooting range setting screen in which the shooting range is set and the shooting range is displayed on the display unit 129. When the first point is designated on the shooting range setting screen, the data of the first point is transmitted from the main control unit 121 to the voice control unit 152, and the voice control unit 152 starts shooting from the data of the first point. The distance from the position to the first point is obtained. In addition, the voice control unit 152 receives movement amount data calculated from the movement speed and elapsed time of the top board 133 from the main control unit 121, and outputs a previous voice when the movement amount reaches the determined distance.

  Similarly, when the second point for outputting the voice for releasing the breath holding instruction is designated on the shooting range setting screen, the voice control unit 152 obtains the distance from the shooting start position to the second point and receives the received movement. When the value of the quantity data reaches the determined distance, a post-sound is output.

(Third Modification)
Next, a third modification of the first embodiment will be described. In the X-ray CT apparatus according to the first modification, the output timing of the front voice and the rear voice is set based on the imaging start position Px of the imaging range, the distance between the start point P1 and the end point P2 of the range in which body movement is likely to occur, and the movement amount. Regarding the configuration, the X-ray CT apparatus of the present invention may have the following configuration, for example.

  That is, in the X-ray CT apparatus according to the third modified example, a plurality of transmission units (not shown) arranged at predetermined intervals in the moving direction of the top plate 133 are provided with respect to the top plate 133. Is provided with a receiver for receiving a signal from the transmitter. Further, the shooting range setting screen is configured to be able to set the transmitter that is closest to the first point that outputs the previous voice and the transmitter that is closest to the second point that outputs the voice of the subsequent voice. Yes.

  When the transmitting unit closest to the first point and the transmitting unit closest to the second point are set, the main control unit 121 stores data relating to the positions of these transmitting units. When the top 133 moves, photographing is started, and the receiving unit in the gantry device 110 receives a signal from the transmitting unit related to the stored data, the main control unit 121 transmits the signal to the voice control unit 152. The voice control unit 152 controls the output unit 151 to output the front voice and the rear voice.

(Fourth modification)
Next, an X-ray CT apparatus according to a fourth modification of the first embodiment will be described. In the X-ray CT apparatus according to the first embodiment, a breath holding instruction and a breath holding release instruction to the subject are performed by voice, but display means (not shown) that can be recognized not only by voice but also visually. Or may be instructed to hold and release the breath by voice and display.

(5th modification)
Next, an X-ray CT apparatus according to a fifth modification of the first embodiment will be described. The X-ray CT apparatus according to the first embodiment has a configuration in which the top plate 133 is moved when imaging the subject, and the imaging is performed by moving the gantry device 110 close to the top plate 133. Also good. In this case, the voice control unit 152 controls the voice output timing based on the moving speed of the gantry device 110 in the voice output control.

(Second Embodiment)
Next, an X-ray CT apparatus according to a second embodiment of the present invention will be described with reference to FIGS. FIG. 5 is a schematic side view showing a state in which the pre-scan shifts to the main scan in the X-ray CT apparatus according to the second embodiment of the present invention. FIG. 6 is a flowchart showing an outline of the operation of the X-ray CT apparatus in the second embodiment of the present invention.

  In the X-ray CT apparatus according to the second embodiment, a storage unit (not shown) in the main control unit 121 stores a first threshold value of a CT value that triggers the start of the main scan. The main scan is to perform imaging of the subject while relatively moving the imaging region of the couchtop device 130 and the gantry device 110. The voice control unit 152 stores a second threshold value that triggers the output of the front voice and the rear voice. This second threshold value is set to be lower than the first threshold value.

(Pre-scan)
The X-ray CT apparatus according to the second embodiment performs pre-scanning before executing main scanning. In this pre-scan, first, the top 133 of the bed apparatus 130 is moved until the specific part of the subject lying on the bed reaches the imaging region of the gantry apparatus 110, and when the specific part of the subject reaches the imaging region, the top plate 133 is moved. The position of the plate 133 is fixed, and the gantry device 110 emits X-rays from the X-ray tube 112 with the plate 133 fixed, and the X-rays transmitted through the subject are detected by the X-ray detector 113, and the detected X-rays This is a test for measuring the CT value of a specific part of a specimen. This specific site is a site that may be necessary for diagnosis in the subject.

  That is, the scan control unit 122 moves the top board 133 by the bed apparatus 130 and causes the specific part of the subject lying on the bed apparatus 110 to reach the imaging region of the gantry apparatus 110. When the specific part reaches the imaging region, the scan control unit 122 stops driving the bed driving unit 131 and fixes the position of the top board 133 (for example, Z0 in FIG. 5). When the position of the top plate 133 is fixed, the scan control unit 122 drives the gantry driving unit 114, the high voltage generation unit 115, and the aperture driving unit 117 in the gantry device 110, and X is applied to a specific part of the subject in the imaging region. The X-ray is detected by exposing the line. The image generation unit 123 detects a CT value based on the detected X-ray. The detected CT value is transmitted to the main control unit 121.

  It is possible to observe the concentration of the contrast agent flowing into a specific part of the subject by the CT value measured by the prescan, and it is possible to trigger the start of the main scan by the concentration of the contrast agent. As a result, it is possible to avoid a situation in which imaging starts in a state where the concentration of the contrast agent in a specific part of the subject is low and does not reach the level of imaging, and the image quality of the X-ray CT image is deteriorated Can be prevented.

  When the main control unit 121 receives the CT value, the main control unit 121 compares it with the first threshold value stored in the storage unit. When the CT value reaches the first threshold value, the main control unit 121 transmits a scan switching signal to the scan control unit 122. Upon receiving the scan switching signal, the scan control unit 122 returns the top board 133 to the base 132 side Z1 as shown in FIG. 5, switches to the main scan, and executes imaging of the subject.

(Audio output control)
The main control unit 121 transmits the CT value measured by the pre-scan to the voice control unit 152. Upon receiving the CT value, the voice control unit 152 compares the CT value with a second threshold value stored in a storage unit (not shown), and when the CT value reaches the second threshold value, drives the output unit 151 to output the previous voice.

  The second threshold value may be set by the inspector together with the first threshold value by the input unit 128 at a time point before the pre-scan. Alternatively, the voice control unit 152 may calculate and set the previous voice to be output immediately before the CT value reaches the first threshold value based on the increasing speed of the CT value.

  That is, first, the voice control unit 152 continues to calculate the average value of the increase rate of the CT value, thereby continuing to calculate the remaining time from the current CT value until the first threshold value is reached. Furthermore, the voice control unit 152 causes the output unit 151 to output the previous voice when the time (for example, 2 seconds) from the start of outputting the previous voice to the completion of the output becomes equal to the calculated remaining time. You may comprise as follows.

(Operation)
Next, the operation of the X-ray CT apparatus in the first embodiment described above will be described with reference to FIG. FIG. 3 is a flowchart showing an outline of the operation of the X-ray CT apparatus in the first embodiment of the present invention.

(Step 21)
The scan control unit 122 in the X-ray CT apparatus drives the bed driving unit 131 of the bed apparatus 130 and moves the top board 133 until the specific part of the subject lying on the bed reaches the imaging region of the gantry apparatus 110. .

(Step 22)
When the specific part of the subject reaches the imaging region, the scan control unit 122 stops driving the bed driving unit 131 and fixes the position of the top board 133.

(Step 23)
When the position of the top plate 133 is fixed, the scan control unit 122 emits X-rays from the X-ray tube 112 and detects the X-rays with the X-ray detector 113. The image generation unit 123 measures the CT value of a specific part of the subject from the detected X-ray.

(Step 24)
The voice control unit 152 determines whether the CT value received from the image generation unit 123 via the main control unit 121 has reached a preset second threshold value.

(Step 25)
If the voice control unit 152 determines that the CT value has reached the second threshold value (step 24; Yes), the voice control unit 152 causes the output unit 151 to output the previous voice.

(Step 26)
The main control unit 121 determines whether the CT value received from the image generation unit 123 has reached a preset first threshold value.

(Step 27)
When the voice control unit 152 determines that the CT value has reached the second threshold (step 26; Yes), the scan control unit 122 performs the main scan.

(effect)
The X-ray CT apparatus according to the first embodiment sets the second threshold value lower than the first threshold value that triggers the main scan, so that the CT value of the specific part of the monitored subject reaches the second threshold value. As a result, the voice control unit 152 causes the output unit 151 to output the previous voice.

  Therefore, immediately before the concentration of the contrast medium flowing into the subject reaches the level at which the main scan is performed, the previous voice is output, and the time point when the subject starts to hold the breath corresponds to the timing at which the main scan should be started. It becomes possible. As a result, the time from the pre-scan to the main scan for monitoring the inflow of contrast medium can be shortened. That is, it is possible to prevent deterioration of the image quality of the X-ray CT image due to disappearance of the contrast agent at a specific part of the subject during the main scan or a decrease in density. Furthermore, it is possible to reduce the amount of contrast medium flowing into the subject.

1 is a schematic block diagram showing a schematic configuration of an X-ray CT apparatus according to an embodiment of the present invention. It is the schematic which shows the setting screen of the imaging | photography range and audio | voice output position concerning embodiment of this invention. It is a flowchart which shows the outline of operation | movement of the X-ray CT apparatus in 1st Embodiment of this invention. It is a flowchart which shows the outline of operation | movement of the X-ray CT apparatus in 1st Embodiment of this invention. It is a schematic side view which shows the state which transfers to a main scan from the X-ray CT apparatus concerning 2nd Embodiment of this invention. It is a flowchart which shows the outline of operation | movement of the X-ray CT apparatus in 2nd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 110 Mount apparatus 111 Rotating mount 112 X-ray tube 113 X-ray detector 114 Mount drive part 115 High voltage generation part 116 Collimator 117 Diaphragm drive part 118 Data collection part 120 Console part 121 Main control part 122 Scan control part 123 Image generation part 124 Pre-processing unit 125 Projection data storage unit 126 Reconstruction unit 127 Image processing unit 128 Input unit 129 Display unit 130 Bed device 131 Bed drive unit 132 Base 133 Top plate 140 Biological signal detection device 150 Instruction unit 151 Output unit 152 Audio control unit

Claims (5)

A gantry device for imaging a subject, range setting means for setting an imaging range in the gantry device in advance, and a couch device provided with a couch on which the subject is lying, the gantry device and the couch An X-ray CT apparatus for imaging the imaging range while relatively moving in the body axis direction of the subject,
Instruction means for instructing the subject to hold and release the breath;
Timing for setting a first point after the shooting start position of the shooting range set in advance by the range setting means and setting a second point between the shooting end position and the first point Setting means;
After the start of photographing, as the top plate moves, the instruction means causes the instruction means to execute the breath-holding instruction when the first point is detected, and the instruction when the second point is detected. An X-ray CT apparatus comprising: control means for causing the means to execute an instruction for releasing the breath-holding. The control means includes
Calculate the amount of movement of the top plate based on the elapsed time from the time of starting the shooting and the preset moving speed of the top plate,
When the movement amount reaches the distance from the shooting start position to the first point, the instruction means executes the breath holding instruction, and the movement amount is changed from the shooting start position to the second point. Causing the instruction means to execute the instruction to release the breath-holding when the distance is reached.
The X-ray CT apparatus according to claim 1. The control means includes
Based on a distance from the shooting start position to the first point and a preset first moving speed of the top plate, a first time from the shooting start position to the first point is reached. Calculate
Based on a distance from the shooting start position to the second point and a preset second moving speed of the top board, a second time from the shooting start position to the second point is calculated. And
When the elapsed time from the start of shooting has reached the first time, the instruction means is instructed to hold the breath, and when the elapsed time has reached the second time , Causing the instruction means to execute the instruction to release the breath hold,
The X-ray CT apparatus according to claim 1. A preparation image generating means for generating an imaging preparation image for setting the imaging range of the subject;
Display means for displaying the preparation image,
The range setting means is configured to be able to set the shooting range on the shooting preparation image,
The timing setting means can set the first point and the second point on the photographing preparation image;
The X-ray CT apparatus according to claim 1. An X-ray tube that emits X-rays, a detector that detects X-rays transmitted through the subject, and a bed on which the subject is placed, the bed is stopped, and X-rays are placed on the X-ray tube. X-ray that performs a main scan of the image reconstruction range by moving the X-ray tube, the detector, and the bed relative to each other after a pre-scan to expose the line and measure the CT value in the subject A CT apparatus,
Switching means for switching from the pre-scan to the main scan when the CT value measured by the pre-scan exceeds a preset first threshold;
Instruction means for instructing the subject to hold a breath when the CT value measured by the pre-scan exceeds a second threshold value lower than the preset first threshold value;
X-ray CT apparatus provided with