JP2008113852A - Ct apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a CT apparatus allowing an operator to visibly recognize at a glance whether a set scanning time is appropriate or not. <P>SOLUTION: This CT apparatus displays an estimated contrast curve (A, B) estimating a change in a dyed state of a region of interest by contrast media, and displays scanning times (w1, w2, w3 and w4) set by the operator on a screen associated with the estimated contrast curve (A, B). This method allows the operator to visually view at a glance whether the set scanning time is appropriate or not so as to optimize a scan planning according to the timing of the contrast. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a CT apparatus, and more particularly, to a CT apparatus capable of visually confirming whether a set imaging period is appropriate at a glance and appropriately planning a scan in accordance with an imaging timing.

  Conventionally, an X-ray CT apparatus is known in which a contrast medium is injected into a subject, a low X-ray scan is performed at a tomographic imaging position, and a high X-ray scan is switched based on a CT value of a region of interest on the tomographic image. For example, Patent Document 1 includes, in such an X-ray CT apparatus, a means for displaying a curve indicating a temporal change in CT value, and information such as a CT value of a low X-ray scan or a gradient of the curve. Discloses an X-ray CT apparatus capable of determining the timing of starting a high X-ray scan.

JP 2004-1173779 A

However, in recent years, the imaging time has been shortened to a few seconds due to the use of multi-row detectors, the increase in imaging speed, and the like. There is a problem that it is difficult to set an appropriate shooting period. In particular, in the case of multiple time phase imaging corresponding to the degree of staining of the contrast agent, it is difficult to set the imaging period of each time phase according to the degree of contrast agent staining.
SUMMARY OF THE INVENTION An object of the present invention is to provide a CT apparatus that can recognize at a glance whether or not a set imaging period is appropriate and can appropriately plan a scan in accordance with the contrast timing.

In a first aspect, the present invention relates to a predicted contrast curve storage unit that stores a predicted contrast curve that predicts a temporal change in CT value of a region of interest at a tomographic imaging position after injecting a contrast agent into a subject. An imaging period setting means for an operator to set an imaging period of the region of interest at the tomographic imaging position after injecting a contrast medium into the specimen, and displaying the predicted contrast curve on the screen and corresponding to the predicted contrast curve In addition, there is provided a CT apparatus comprising display control means for displaying an imaging period set by the operator on a screen.
In the CT apparatus according to the first aspect, the predicted contrast curve is displayed on the screen, and the imaging period set by the operator is displayed on the screen in association with the predicted contrast curve. Thereby, since it is possible to visually recognize whether or not the set imaging period is appropriate, it is possible to appropriately plan a scan in accordance with the contrast timing.

In a second aspect, the present invention provides the CT apparatus according to the first aspect, wherein the display control means displays the predicted contrast curve in a curve graph having time as a horizontal axis and CT value as a vertical axis, and horizontal. There is provided a CT apparatus characterized by displaying the imaging period in a band graph along an axis.
In the CT apparatus according to the second aspect, whether or not the set imaging period is appropriate between the curve graph of the predicted contrast curve representing the temporal change of the CT value and the band graph of the imaging period representing the timing of the start and end of imaging. You can see at a glance.

In a third aspect, the present invention provides the CT apparatus according to the first or second aspect, wherein the imaging period setting means includes means for setting a plurality of the imaging periods with a non-imaging period interposed therebetween. Provided is a CT apparatus including the CT apparatus.
According to the third aspect, for example, in the case of setting a plurality of shooting periods in the case of a plurality of time phase shootings according to the degree of staining of the contrast agent, whether or not the set shooting period is appropriate is determined as a contrast curve. Since it can be visually recognized at a glance, it is possible to appropriately plan a scan in accordance with the timing according to the state of contrast medium penetration.

In a fourth aspect, the present invention provides the CT apparatus according to any one of the first to third aspects, wherein the display control means displays a predicted contrast curve of a plurality of regions of interest together. Providing equipment.
According to the fourth aspect, since a plurality of regions of interest in a tomographic image such as an artery and a vein can be displayed simultaneously, it is possible to visually recognize whether or not the set imaging period is appropriate for the plurality of regions of interest. Scanning can be planned appropriately according to the contrast timing.

In a fifth aspect, the present invention provides the CT apparatus according to any one of the first to fourth aspects, wherein the predicted contrast curve is stored corresponding to a scan protocol. Providing equipment.
In the CT apparatus according to the fifth aspect, an optimum predicted contrast curve can be used for various scanning protocols.

In a sixth aspect, the present invention provides the CT apparatus according to any one of the first to fifth aspects, wherein the imaging period is set as a default, and the display control means sets the default imaging period. Provided is a CT apparatus characterized by being displayed on an initial screen.
In the CT apparatus according to the sixth aspect, since the default imaging period is displayed on the initial screen, the operator can easily perform a scan plan based on the default imaging period.

In a seventh aspect, the present invention provides the CT apparatus according to the sixth aspect, comprising a default imaging period creating means for creating the default imaging period based on a predicted contrast curve displayed on a screen. A CT apparatus is provided.
In the CT apparatus according to the seventh aspect, since the default imaging period is created from the predicted contrast curve, the change operation by the operator can be minimized.

In an eighth aspect, the present invention is characterized in that in the CT apparatus according to the sixth aspect, there is provided a default imaging period creating means for creating the default imaging period based on an imaging period set in the past. A CT apparatus is provided.
In the CT apparatus according to the eighth aspect, since the default imaging period is created from the learning result, the change operation by the operator can be minimized.

  According to the CT apparatus of the present invention, the predicted contrast curve is displayed on the screen, and the imaging period set by the operator is displayed on the screen in association with the predicted contrast curve. You can see at a glance. For this reason, a scan plan can be appropriately performed in accordance with the contrast timing.

  Hereinafter, the present invention will be described in more detail with reference to embodiments shown in the drawings. Note that the present invention is not limited thereby.

FIG. 1 is a configuration block diagram of an X-ray CT apparatus 100 according to the first embodiment.
The X-ray CT apparatus 100 includes an operation console 1, a table apparatus 10, and a scanning gantry 20.

  The operation console 1 includes an input device 2 that receives input from an operator, a central processing unit 3 that executes image reconstruction processing, a data collection buffer 5 that collects projection data acquired by the scanning gantry 20, and a projection data. A display device 6 that displays the reconstructed tomographic image and a storage device 7 that stores programs, data, and X-ray tomographic images are provided.

The storage device 7 stores one of the following predicted contrast curves corresponding to the scan protocol.
(1) An average predicted contrast curve created on the basis of data measured in advance for a plurality of subjects different from the subject performing the main imaging.
(2) A predicted contrast curve created based on the data obtained by injecting a small amount of a contrast medium for testing into the subject to be imaged, measuring the time change of the CT value at the tomographic image capturing position, and the obtained data.
(3) A predicted contrast curve in which the time change of the CT value obtained at another opportunity by the operator is registered in advance.

The storage device 7 stores one of the following scan plans as a default scan plan corresponding to the stored predicted contrast curve.
(1) Standard scan plan.
(2) A scan plan set in the past.

  The table apparatus 10 includes a cradle 12 that puts a subject and puts it in and out of a bore (cavity) of the scanning gantry 20. The cradle 12 is moved up and down (y-axis direction) and linearly moved (z-axis direction) by a motor built in the table apparatus 10.

  The scanning gantry 20 includes an X-ray tube 21, an X-ray controller 22, a collimator 23, a multi-row X-ray detector 24, a DAS (Data Acquisition System) 25, and an X-ray tube around the body axis of the subject. A rotation controller 26 that rotates 21 and the like, a tilt controller 27 that performs control when the scanning gantry 20 is tilted forward or backward of the rotation axis, and a control controller 29 that exchanges control signals and the like with the operation console 1 and the bed apparatus 10. And a slip ring 30.

  The linear movement amount of the cradle 12 is counted by an encoder built in the table device 10, the controller 29 calculates the z-axis coordinate of the cradle 12 from the linear movement amount, and the z-axis coordinate is supplied to the DAS 25 via the slip ring 30. Sent.

  The projection data obtained by the multi-row X-ray detector 24 is AD-converted by the DAS 25, z-axis coordinates are added, and the data is transferred to the data acquisition buffer 5 via the slip ring 30.

  The central processing unit 3 performs preprocessing and image reconstruction processing on the projection data collected in the data collection buffer 5, generates a tomographic image, and displays the tomographic image on the display device 6.

FIG. 2 is a flowchart showing a procedure of scan plan setting processing using the X-ray CT apparatus 100.
In step P1, the operator operates the input device 2 to select a scan protocol. For example, a contrast medium is injected into the artery of the arm, and a scanning protocol is selected that helically images the area covering the liver from a little below the heart in four time phases.

  In step P2, the central processing unit 3 uses the predicted contrast curve corresponding to the selected scan protocol and the default scan among the predicted contrast curves stored in the storage device 7 corresponding to the various scan protocols. Read the plan.

  In step P3, the central processing unit 3 displays the read predicted contrast curve and the default scan plan on the display device 6 like the curve graphs A and B and the strip graphs # 1 to # 4 shown in FIG. For example, the curve graph A is a time change of the CT value of the abdominal aorta (the artery just below the heart) that is a region of interest when a contrast medium is injected into the artery of the arm. A curve graph B is a temporal change in CT value of the abdominal vena cava (a vein just below the heart) that is a region of interest when a contrast medium is injected into the artery of the arm. The band graph # 1 is helical imaging that starts after time t1 from the start of contrast agent injection and continues for time w1. The band graph # 2 is helical imaging that starts after the time t2 from the end of the helical imaging of # 1 and continues for the time w2. The band graph # 3 is helical imaging that starts after the time t3 from the end of the helical imaging of # 2 and continues for the time w3. Band graph # 4 is helical imaging that starts after time t4 from the end of helical imaging of # 3 and continues for time w4. It should be noted that there is a non-imaging period from the injection of the contrast agent before the start of the first imaging and from the end of the previous imaging to the start of the next imaging.

  In Step P4, the operator determines whether or not to re-input the scan plan by looking at the display of the predicted contrast curve and the scan plan, and operates the input device 2 to give an instruction. The central processing unit 3 terminates the processing if it is an instruction not to re-input the scan plan (after that, the main imaging is performed according to the set scan plan). If it is an instruction to re-input the scan plan, the process proceeds to Step P5.

In Step P5, the operator operates the input device 2 to change the current scan plan to a desired scan plan.
In step P6, the central processing unit 3 displays the predicted contrast curve and the new scan plan on the display device 6. Then, the process returns to Step P4.

  According to the X-ray CT apparatus 100 of the first embodiment, a predicted contrast curve is displayed on the screen and a scan plan is displayed on the screen in association with the predicted contrast curve. Visible at. Therefore, it is possible to plan a scan appropriately in accordance with the contrast timing.

  As in step S2 of the flowchart shown in FIG. 4, a small amount of test contrast medium is injected into the subject to be imaged, and the time change of the CT value at the tomographic imaging position is measured, and the obtained data When using a predicted contrast curve created based on the above, a default scan plan may be created based on the predicted contrast curve as in step S3 (for example, the peak of time-varying CT values in arteries and The vicinity is set as the first shooting period, the period starting to fall from the peak is set as the second shooting period, the fixed period after the fixed period from the second shooting period is set as the third shooting period, and fixed from the third shooting period. A fixed period after the time is set as a fourth imaging period).

  The CT apparatus of the present invention can be used for tomographic imaging using a contrast agent.

1 is a block diagram illustrating an X-ray CT apparatus according to Embodiment 1. FIG. FIG. 10 is a flowchart illustrating a procedure of scan plan setting processing according to the first embodiment. It is an illustration figure which shows the prediction contrast curve and scan plan which are displayed on a screen. FIG. 10 is a flowchart illustrating a procedure of scan plan setting processing according to the second embodiment.

Explanation of symbols

1 Operation Console 2 Input Device 3 Central Processing Unit 6 Display Device 7 Storage Device 10 Table Device 20 Scanning Gantry 100 X-ray CT Device

Claims (8)

Predicted contrast curve storage means for storing a predicted contrast curve for predicting temporal changes in CT values of the region of interest at the tomographic imaging position after injecting the contrast agent into the subject, and the above-mentioned after the contrast agent has been injected into the subject An imaging period setting means for an operator to set an imaging period of a region of interest at a tomographic imaging position, and the imaging set by the operator in association with the predicted contrast curve while displaying the predicted contrast curve on the screen A CT apparatus comprising display control means for displaying a period on a screen. 2. The CT apparatus according to claim 1, wherein the display control unit displays the predicted contrast curve with a curve graph having time as a horizontal axis and CT value as a vertical axis, and the imaging period in a band graph along the horizontal axis. CT apparatus characterized by displaying. 3. The CT apparatus according to claim 1, wherein the imaging period setting means includes means for setting a plurality of imaging periods with a non-imaging period interposed therebetween. 4. The CT apparatus according to claim 1, wherein the display control unit displays a predicted contrast curve of a plurality of regions of interest together. 5. 5. The CT apparatus according to claim 1, wherein the predicted contrast curve is stored in correspondence with a scan protocol. 6. The CT apparatus according to claim 1, wherein the imaging period is set as a default, and the display control unit displays the default imaging period on an initial screen. CT device. 7. The CT apparatus according to claim 6, further comprising default imaging period creating means for creating the default imaging period based on a predicted contrast curve displayed on a screen. 7. The CT apparatus according to claim 6, further comprising default imaging period creating means for creating the default imaging period based on an imaging period set in the past.

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