JP2008142388A - X-ray ct apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an X-ray CT apparatus having a user interface capable of easily and integrally obtaining a scanning position and time. <P>SOLUTION: The X-ray CT apparatus scans a subject with X-rays and re-constitutes a tomographic image, based on the obtained data. A scanning plan is generated with the use of a chart expressing relation between the scanning position and time through a user interface which displays a two-dimensional coordinate space where two coordinate axes are respectively a distance axis and a temporal axis. The chart includes a diagram and a block diagram. The time includes the delay of scanning. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an X-ray CT (Computed Tomography) apparatus, and more particularly to an X-ray CT apparatus having a user interface for supporting a scan plan.

  The X-ray CT apparatus scans a subject with X-rays, and reconstructs a tomographic image based on the obtained data (data). The X-ray CT apparatus has a user interface for enabling an interactive operation by a user.

The user interface is also used for scan planning. As part of creating a scan plan, a fluoroscopic image of a subject is displayed on a user interface, and a scan position is set on the fluoroscopic image (see, for example, Patent Document 1).
JP 2006-136418 A

  When planning scans, time is planned in addition to position. A tabular user interface is used for time planning. Since this user interface has a different format from the interface for position planning, it is difficult to integrally grasp the relationship with the scan position.

  Therefore, an object of the present invention is to realize an X-ray CT apparatus having a user interface that allows easy understanding of the scan position and time.

  An invention for solving the problem is an X-ray CT apparatus that scans a subject with X-rays and reconstructs a tomographic image based on the obtained data, and one of the two coordinate axes is a distance axis. An X-ray CT apparatus comprising a user interface that displays a two-dimensional coordinate space that is a time axis and enables a scan plan to be created by a chart that represents a relationship between a scan position and time.

  It is preferable that the chart includes a diagram because it is easy to integrally grasp the scan position and time. It is preferable that the chart includes a block diagram in terms of easy integration of the scan position and time. The time preferably includes a scan delay in terms of planning a scan with a delay.

 The delay is preferably a preparation delay in terms of planning a scan with a preparation delay. The delay is preferably an intergroup delay in terms of planning a scan with an intergroup delay. The delay is preferably an interscan delay in terms of planning a scan with an interscan delay.

  According to the present invention, it is possible to create a scan plan with a chart representing a relationship between a scan position and time through a user interface that displays a two-dimensional coordinate space in which one of the two coordinate axes is a distance axis and a time axis, respectively. Therefore, it is possible to realize an X-ray CT apparatus having a user interface that makes it easy to integrally grasp the scan position and time.

  The best mode for carrying out the invention will be described below with reference to the drawings. Note that the present invention is not limited to the best mode for carrying out the invention. FIG. 1 shows a schematic configuration of an X-ray CT apparatus. This apparatus is an example of the best mode for carrying out the present invention. An example of the best mode for carrying out the invention related to the X-ray CT apparatus is shown by the configuration of the apparatus.

  The apparatus has a gantry 100, a table 200, and an operator console 300. The gantry 100 scans the subject 10 carried by the table 200 with the X-ray irradiation / detection device 110, collects transmission X-ray signals (scan data) of a plurality of views, and inputs them to the operator console 300. . The operator console 300 performs image reconstruction based on the scan data input from the gantry 100 and displays the reconstructed image on a display 302.

  The operator console 300 also displays a user interface on the display 302 for enabling the user to interactively operate the apparatus. The user interface includes a user interface for scan plan support described later. The display for displaying the user interface may be different from the display for displaying the reconstructed image.

  The operator console 300 also controls the operation of the gantry 100 and the table 200. Under the control of the operator console 300, the gantry 100 scans under a predetermined scan condition, and the table 200 positions the subject 10 so that a predetermined part is scanned. Positioning is performed by adjusting the height of the top plate 202 and the horizontal movement distance of the cradle 204 on the top plate by a built-in position adjustment mechanism.

  An axial scan can be performed by scanning with the cradle 204 stopped. A cine scan can be performed by continuously performing a plurality of scans while the cradle 204 is stopped.

 A helical scan can be performed by continuously performing a plurality of scans while continuously moving the cradle 204. A cluster scan can be performed by scanning each cradle 204 while intermittently moving the cradle 204.

  The height adjustment of the top plate 202 is performed by swinging the support column 206 around the attachment portion to the base 208. The top plate 202 is displaced in the vertical direction and the horizontal direction by the swing of the column 206. The cradle 204 moves in the horizontal direction on the top plate 202 to cancel the horizontal displacement of the top plate 202. Depending on the scan conditions, the scan is performed with the gantry 100 tilted. The gantry 100 is tilted by a built-in tilt mechanism.

  As shown in FIG. 2, the table 200 may be of a type in which the top plate 202 moves up and down vertically with respect to the base 208. The top plate 202 is moved up and down by a built-in lifting mechanism. In this table 200, the horizontal movement of the top plate 202 accompanying the raising and lowering does not occur.

  FIG. 3 schematically shows the configuration of the X-ray irradiation / detection device 110. The X-ray irradiation / detection device 110 detects an X-ray 134 emitted from the focal point 132 of the X-ray tube 130 with an X-ray detector 150.

  The X-ray 134 is shaped by a collimator (not shown) and is a symmetrical cone beam or fan beam X-ray. The X-ray detector 150 has an X-ray incident surface 152 that expands two-dimensionally corresponding to the spread of X-rays. The X-ray incident surface 152 is curved so as to constitute a part of a cylinder. The central axis of the cylinder passes through the focal point 132.

  The X-ray irradiation / detection device 110 rotates around a central axis passing through an imaging center, that is, an isocenter O. The central axis is parallel to the central axis of the partial cylinder formed by the X-ray detector 150.

  The direction of the center axis of rotation is the z direction, the direction connecting the isocenter O and the focal point 132 is the y direction, and the direction perpendicular to the z direction and the y direction is the x direction. These three axes in the x, y, and z directions are the three axes of the rotating coordinate system with the z axis as the central axis.

  FIG. 4 schematically shows a plan view of the X-ray incident surface 152 of the X-ray detector 150. The X-ray incident surface 152 has detection cells 154 arranged two-dimensionally in the x direction and the z direction. That is, the X-ray incident surface 152 is a two-dimensional array of detection cells 154. In the case of using fan beam X-rays, the X-ray incident surface 152 may be a one-dimensional array of detection cells 154.

  Each detection cell 154 constitutes a detection channel of the X-ray detector 150. As a result, the X-ray detector 150 becomes a multi-channel X-ray detector. The detection cell 154 is configured by, for example, a combination of a scintillator and a photodiode.

  The scan plan creation will be described. A user interface displayed on the display 302 is used for creating a scan plan. Hereinafter, creation of a scan plan is also simply referred to as a scan plan.

  FIG. 5 shows an example of a user interface used at the time of scan planning. As shown in FIG. 5, the user interface is an image representing a two-dimensional coordinate space. One of the two coordinate axes in the two-dimensional coordinate space is a distance axis z and the other is a time axis t. Both axes have a scale. The distance is a distance in the body axis direction. The coordinate origin of the distance axis z is a predetermined reference position. The coordinate origin of the time axis t is a predetermined reference time.

  The scan plan is performed by drawing a diagram as shown in FIG. 6 on the user interface. The diagram is composed of a vertical line segment and a diagonal line segment. The drawing of the diagram is performed using a pointing device provided in the operator console. A diagram is an example of a chart in the present invention. In FIG. 6, the scale of the coordinate axes is omitted. The same applies hereinafter.

  In FIG. 6, the scan position and time are represented by two diagrams for two groups of scans. In each diagram, the vertical line segment represents an axial scan. The length represents the scan time, and the position on the distance axis represents the scan position. The diagonal line segment represents a change in scan position.

 For the first group scan, the axial scan from the time t1 to t2 at the position of the distance z1, the axial scan from the time t3 to t4 at the position of the distance z2, and the axial scan from the time t5 to t6 at the position of the distance z3. A scan is planned. A series of these axial scans constitutes a cluster scan. Each axial scan may be a cine scan.

 Regarding the scan of the second group, the axial scan from the time t7 to t8 at the position of the distance z4, the axial scan from the time t9 to t10 at the position of the distance z5, and the axial scan from the time t11 to t12 at the position of the distance z6. A scan is planned. A series of these axial scans constitutes a cluster scan. Each axial scan may be a cine scan.

 The time interval from time t0 to time t1 represents the preparation delay of the first group of scans. The time interval from time t6 to time t7 represents the inter group delay of the second group of scans. The time interval from the end of one scan to the start of the next scan in each group represents the interscan delay.

 In this way, the diagram visually represents the relationship between the scan position, scan time, preparation delay, intergroup delay, and interscan delay, so the user can determine the scan position and time. It is very easy to grasp as one.

 The scan plan is completed by drawing a diagram according to the desired scan position, scan time, preparation delay, intergroup delay, interscan delay, etc., so it is very easy to create a scan plan. be able to.

 FIG. 7 shows an example of a scan plan for the helical scan. As shown in FIG. 7, the scan of the first group is a continuous scan from the distance z1 to z3 from the time t1 to t6 by a straight line connecting the two coordinates (z1, t1) and (z3, t6). The scan of the second group is performed by a straight line connecting two coordinates (z4, t7) and (z6, t12), and a continuous scan from the distance z4 to z6 is performed from time t7 to t12. Planned as a thing.

 The time interval from time t0 to t1 is a preparation delay, and the time interval from time t6 to t7 is an intergroup delay or an interscan delay.

 FIG. 8 shows another example of the scan plan for the helical scan. As shown in FIG. 8, the scan of the first group is a rectangular block having vertices at four coordinates (z1, t1), (z1, t6), (z3, t6), (z3, t1). According to the figure, it is planned that a continuous scan from the distance z1 to z3 is performed from the time t1 to the time t6, and the scan of the second group has four coordinates (z4, t7), (z4, t12), (z6, t12). ), (Z6, t7), and a rectangular block diagram having vertices, it is planned that a continuous scan from distance z4 to z6 is performed from time t7 to time t12. By using the block diagram, it is possible to clarify the grouping of scans. The block diagram is an example of a chart in the present invention.

 FIG. 9 shows another example of the scan plan for the helical scan. As shown in FIG. 9, the helical scan uses a straight line connecting three coordinates (z1, t1), (z4, t6), (z6, t12) in order, and a continuous scan from a distance z1 to z4 It is planned to perform from t1 to t6, and to perform a continuous scan from distance z4 to z6 from time t6 to t12. The scan from the distance z1 to z4 and the scan from the distance z4 to z6 have different scan speeds. This is indicated by the difference in slope between the two lines.

 An example in which the same scan plan is performed in a block diagram is shown in FIG. As shown in FIG. 10, a helical scan whose speed changes along the way is planned by two rectangular block diagrams. Two block diagrams share one vertex. The difference in scan speed is indicated by the dissimilarity of the rectangle.

 FIG. 11 shows another example of a scan plan based on a diagram. The diagram is drawn as a sine curve-like curve connecting four coordinates (z1, t1), (z6, t5), (z1, t8), (z6, t12) in this order. As a result, a helical scan that reciprocates 1.5 times in the range from the distance z1 to z6 from time t1 to t12 is planned. Helical scans that reciprocate in the same range are also called shuttle scans.

It is a figure which shows the structure of the X-ray CT apparatus of an example of the best form for implementing this invention. It is a figure which shows the structure of the X-ray CT apparatus of an example of the best form for implementing this invention. It is a figure which shows the structure of a X-ray irradiation / detection apparatus. It is a figure which shows the structure of the X-ray entrance plane of an X-ray detector. It is a figure which shows an example of the user interface used at the time of a scan plan. It is a figure which shows an example of a scanning plan. It is a figure which shows an example of a scanning plan. It is a figure which shows an example of a scanning plan. It is a figure which shows an example of a scanning plan. It is a figure which shows an example of a scanning plan. It is a figure which shows an example of a scanning plan.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10: Subject 100: Gantry 110: X-ray irradiation / detection apparatus 130: X-ray tube 132: Focus 134: X-ray 150: X-ray detector 152: X-ray incident surface 154: Detection cell 200: Table 202: Top plate 204: Cradle 206: Prop 208: Base 300: Operator console 302: Display

Claims (7)

An X-ray CT apparatus that scans a subject with X-rays and reconstructs a tomogram based on the obtained data,
A two-dimensional coordinate space in which one of the two coordinate axes and the other is a distance axis and a time axis is displayed, and a user interface is provided that enables creation of a scan plan with a chart representing the relationship between the scan position and time. X-ray CT system. The X-ray CT apparatus according to claim 1, wherein the chart includes a diagram. The X-ray CT apparatus according to claim 1, wherein the chart includes a block diagram. The X-ray CT apparatus according to claim 1, wherein the time includes a scan delay. The X-ray CT apparatus according to claim 4, wherein the delay is a preparation delay. The X-ray CT apparatus according to claim 4, wherein the delay is an intergroup delay. The X-ray CT apparatus according to claim 4, wherein the delay is an interscan delay.

Images