JPH0432660B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a dynamic image data processing device for obtaining images of a periodically moving subject, such as a heart gate scan in X-ray CT. It is something.

(Prior art) For example, in a heart gate scan of X-ray CT, multiple heart beats are detected during one scan, so if multiple scans are performed intermittently, the same heartbeat phase A certain amount of nearby data is collected. Therefore, based on data of the same heartbeat phase, a still image of that phase can be reconstructed.

When reconstructing an image, data near the designated phase is necessary for all views, but the quality of the image is strongly affected by the degree to which the collected data varies from the designated phase. With conventional devices, there is no way to clearly represent the correspondence between a designated heartbeat phase and a view. Further, information such as heartbeat cycle was shown only by numerical values.

(Problems to be Solved by the Invention) In such conventional devices, it is difficult to understand the degree of view dispersion within a heartbeat cycle, and the image quality at a specified phase cannot be predicted until a reconstructed image is obtained. . Furthermore, information consisting only of numerical values is nothing more than a list of numbers, making it difficult to understand the situation and only making vague inferences, making it difficult to intuitively understand heartbeat phase shifts. Such problems are not limited to heart gate scans, but are common when obtaining still images of a moving subject.

The purpose of the present invention is to graphically display the correspondence between the motion phase of the subject and the view, so that the degree of dispersion of the view within the motion phase can be intuitively understood, and the quality of the reconstructed image at a specified phase can be improved. An object of the present invention is to provide a dynamic image data processing device that can be easily predicted.

(Means for Solving the Problems) The present invention provides a means for detecting a moving subject from a plurality of directions, a means for detecting a motion cycle of the subject, and a means for detecting a subject in multiple directions in which the subject is detected. Dynamic image data processing that includes means for graphically displaying the object according to its motion cycle, and means for displaying a specified range of the object's motion phase overlaid on a graphic display of multiple directions in which the object is detected. This device solves the above problems.

(Function) Based on the graphical display of the correspondence between the motion phase of the object and the view, the degree of dispersion of the view within the motion phase can be intuitively understood, and the image quality of the reconstructed image at a specified phase can be easily determined. It's predictable.

(Embodiment) FIG. 1 is a conceptual block diagram of an embodiment in which the present invention is applied to a heart gate scan of X-ray CT.
In Figure 1, 1 is a display device, for example a CRT.
Graphic displays are suitable, but are not limited to them. Reference numeral 2 denotes a setting device, which is suitably a keyboard, but is not limited to this. 3 is a control and processing device, which is usually configured using a computer. 4 is a scan device,
It consists of an X-ray source, an X-ray detector, and a mechanism for rotating both around the subject. Reference numeral 5 is an electrocardiograph or the like, which detects a signal synchronized with the heart motion of the subject. The control and processing device 3 is connected to the display device 1, setting device 2, and scan device 4, and exchanges signals with them. The control and processing device 3 includes:
Based on commands and data given by the operator through the setting device 2, the scanning device 4 and the display device 1 are controlled and data processing for image reconstruction is performed.
The detection signal of the electrocardiograph 5 is given to the control and processing device 3 through the scan device 4. Such a configuration is compatible with regular X-rays that perform heart gate scans.
This is the same configuration as CT.

As shown in FIG. 2, the scanning of the object by the scan device 4 is performed in order (cw) and reverse order (ccw) in each view 1, 2, 3, to n, set relative to the object O. ) is irradiated with X-rays to collect data.

In the heart gate scan of X-ray CT,
Since multiple heartbeats are detected during one scan, the relationship between the heartbeat phase and the view number can be expressed as shown in the graph of FIG. In Figure 3, the horizontal axis is the view number,
The vertical axis is the heartbeat phase. One cycle of a heartbeat is the period from when the heart is relaxed, until it contracts once, and then relaxes again. 0% and 100% are the periods when the heart is relaxed, and the period is about 40%.
is the maximum contraction state. Here, the graph rising to the right is the scan in the CW direction, and the graph falling to the right is the scan in the CW direction.
This is a scan in the ccw direction, and the graphs with circles and plus marks indicate that they belong to the same scan.

When the control and processing device 3 receives a command from the setting device 2, it causes the display device 1 to display such a heartbeat phase-view graph based on the view number and heartbeat detection signal taken in from the scan device 4. Since heartbeat and scan are asynchronous, the number of graphs increases as the number of scans increases. Therefore, when the number of scans is 6, for example, the fourth
A heartbeat-view graph as shown in the figure is displayed on the screen of the display device 1. For such a graph, if the operator specifies the phase of the heartbeat for which the image is to be reconstructed as, for example, 70%, and specifies the phase tolerance as 20%, then the specified phase line 10 is
and tolerance range lines 11 and 12 are displayed. Then, the portion of the graph that falls within this tolerance range is displayed with, for example, a thicker line 12, brighter brightness, or a different color so that it can be distinguished from other portions. Such display is performed by the control and processing device based on a flow chart such as that shown in FIG. 5, for example.

By viewing such a heartbeat phase-view graph, the operator can clearly grasp the view related to the reconstructed image of the heart at a desired heartbeat phase. Then, by checking to what extent these views fall within the specified phase tolerance range, the image quality of the reconstructed image can be predicted. In other words, if the view represented by the thick line is concentrated at the center of the specified phase tolerance range, the image quality is expected to be good; on the other hand, if the view often falls outside the tolerance range, the image quality may be poor. is expected.
Note that it will be easier to understand if the heartbeat phase on the vertical axis is arranged and the electrocardiogram is also displayed.

Although the above is an example of a heart gate scan of X-ray CT, the present invention is not limited to this, and can be applied to the case where an image of a periodic organ is reconstructed based on its operation period signal.

(Effects of the invention) As described above, according to the present invention, by graphically displaying the correspondence between the motion phase of the subject and the view, the degree of dispersion of the view within the motion phase can be intuitively understood. A dynamic image data processing device in which the image quality of a reconstructed image at a specified phase can be easily predicted can be realized.

[Brief explanation of drawings]

Fig. 1 is a conceptual configuration diagram of an embodiment of the present invention;
The figure is an explanatory diagram of scan and view, Fig. 3 is an explanatory diagram of a heartbeat phase-view graph, Fig. 4 is an example of a display screen of a display device, and Fig. 5 is an example of a flow diagram of a control and processing device. FIG. 1...display device, 2...setting device, 3...control and processing device, 4...scan device, 5...electrocardiograph, etc.

Claims (1)

[Claims] 1. means for detecting a moving subject from a plurality of directions; means for detecting the motion cycle of the subject; and means for graphically displaying the plurality of directions in which the subject is detected in accordance with the motion cycle of the subject; A dynamic image data processing device comprising means for displaying a designated range of a motion phase of a subject overlaid on a graphic display of a plurality of directions in which the subject is detected.