JPH10155786A - X-ray ct apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve a photographing based on the optimum respiration stopping time for an actual subject by inputting the time. SOLUTION: When a subject 20 stops respiration for rehearsal, an operator observes the stoppage of the respiration and depresses a push button 38. A respiration stoppage time measuring device 37 starts its measuring operation. Then, the button is depressed again when the stoppage of the respiration is ended. The measuring operation is ended and the respiration stoppage time is measured. The resulting measured value is brought into a CPU 32 to be held and sent to a photographing sequence setting device 36, thereby accomplishing setting with the photographing sequence setting device 36 based on the measured value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an X-ray CT apparatus that performs imaging while breathing is stopped.

[0002]

2. Description of the Related Art When examining the abdomen or chest of a subject using an X-ray CT apparatus, it is necessary for the subject to temporarily stop breathing during the imaging. And
While the breathing is stopped, imaging is performed for a predetermined number of slices or continuous imaging (spiral imaging method) is performed. Conventionally, with regard to imaging in the state of pause of breathing, an imaging sequence incorporating a breathing instruction is created in advance and executed in many cases.

[0003] The imaging sequence incorporating the respiration instruction is to automatically generate an instruction (by voice or the like) to stop the respiration when it is time to stop respiration during imaging in synchronization with the imaging sequence. It refers to what performs the imaging sequence at the time. If the time during which the subject stops breathing is estimated and set in advance, the sequence is such that the imaging sequence at the time of stopping breathing ends within the set time. This respiratory stop time is manually input by the operator. For example, ask the subject to stop breathing on a trial basis, measure the time with a stopwatch, or estimate from the age and condition of the subject,
Enter this for that time.

[0004]

However, in the prior art, it is not always easy to estimate and measure the respiratory arrest time, and the set respiratory arrest time is often too long or too short. And there was a problem. If the set respiratory hold time is longer than the time that can be actually stopped, respiration will be resumed even though the imaging sequence has not been completed, and the respiratory movement will cause artifacts (false alarms) on the reconstructed image. Image). Conversely, if the set respiratory hold time is shorter than the time that can be actually stopped, the examination becomes inefficient. In addition, setting the respiratory hold time too long imposes an excessive respiratory hold on the subject, and causes a problem that the subject suffers.

[0005] In view of the above, the present invention makes it easy to input the subject's respiratory cessation time, and it is of an appropriate length, causing pain to the subject or resuming breathing during the imaging sequence. It is an object of the present invention to provide an X-ray CT apparatus which can be improved so as not to cause an inconvenience that the imaging sequence is ended while the breathing is stopped for a sufficient time.

[0006]

In order to achieve the above object, in an X-ray CT apparatus according to the present invention, means for irradiating a subject with X-rays, and irradiating the subject with X-rays are provided. Scanning means for scanning the X-ray, X-ray detecting means for receiving X-rays which have been irradiated and transmitted through the subject, means for collecting data from the output of the X-ray detecting means, Calculating means for performing the processing for the configuration, means for automatically measuring the respiratory stop time performed by the subject in rehabilitation, and imaging based on the measured respiratory stop time, the imaging sequence incorporating the respiratory instruction It is characterized in that a sequence setting means and an imaging control means for controlling the scanning means by the setting sequence to execute an imaging sequence incorporating a respiratory instruction are provided.

[0007] When the subject stops breathing prematurely prior to imaging, an operator observing the breathing may perform an operation such as pressing a predetermined push button at the start and end of the breathing operation. The breath holding time is automatically measured. Then, since information regarding the measured respiratory stop time is input to the imaging sequence setting means, setting based on the measured respiratory stop time is possible. Since the imaging sequence in which the breathing instruction is incorporated is set in this manner, the imaging is performed according to the period during which the subject stopped breathing prematurely, and the subject can easily stop breathing. The imaging ends at time. For this reason, there is no possibility that respiration is restarted even before the imaging sequence is completed and artifacts do not occur in the reconstructed image, and the efficiency of the examination is not reduced. In addition, there is no need to force the subject to hold his / her breath for a long period of time, or to cause pain.

[0008]

Next, embodiments of the present invention will be described in detail with reference to the drawings. In FIG. 1, an X-ray tube 12 and an X-ray detector 13 are arranged opposite to each other on a gantry 11, and a data acquisition device 14 is connected to the X-ray detector 13. The X-ray tube 12, X-ray detector 13, and data collection device 14 are attached to a rotating frame (not shown) or the like so as to rotate integrally therewith, and a rotation driving device (in FIG. (Omitted), it is driven to rotate around an axis parallel to the paper surface (axis in the Z direction). Thereby, a predetermined cross section (XY perpendicular to the Z axis) of the subject 20 by the irradiation X-ray is obtained.
Scan in the plane).

The subject 20 is lying on a top plate 21 of a bed 22. In the bed 22, the top plate 21 can move in the vertical direction (Y direction) and the body axis direction of the subject 20 (Z direction) with the subject 20 placed thereon. The bed 22 has a built-in drive unit (omitted in the figure). The movement of the top board 21 causes the subject 20 to be scanned in the Z direction by the irradiation X-ray.

The gantry 11 and the bed 22 are controlled by an imaging control device 31 so that a predetermined imaging sequence is performed. That is, when an instruction regarding the imaging sequence set by the imaging sequence setting unit 36 is given to the imaging control device 31 via the CPU 32, the imaging sequence is automatically executed. For example, when an imaging sequence incorporating a breathing instruction is created in advance and automatically executed, a breathing instruction such as a voice is generated in synchronization with the imaging, and the subject 20 stops breathing accordingly. While the subject 20 is moved and stopped, scanning is sequentially performed at each stop position, and imaging in a plurality of cross sections is performed, or
While the X-ray tube 12, the X-ray detector 13, and the like are rotating, the subject 20 is continuously moved at the same time, a spiral scan is performed, and continuous imaging is performed.

[0011] The respiratory arrest time measuring device 37 is provided with the bed 22.
Push button 3 provided on (or gantry 11 etc.)
When 8 is pressed by the operator, the time measurement is started,
When pressed again, the measurement ends. The time during this period is measured, and the information is captured and held by the CPU 32.
The creation of the imaging sequence in the imaging sequence setting unit 36 is performed based on the measurement time information.

The data collected by the above scan is sent to the image reconstruction device 33 via the CPU 32,
It receives arithmetic processing such as convolution processing and back projection processing by a predetermined reconstruction algorithm. The reconstructed image is stored in the image memory 34 and displayed on the image display device 35.

Here, an example will be described in which the imaging sequence setting unit 36 creates an imaging sequence incorporating a respiratory instruction, automatically executes the imaging sequence, and images the abdomen of the subject 20. As a normal inspection procedure, the operator
Prior to the examination, notes and the like during the examination will be explained to the subject 20. The explanation includes an explanation that a voice instruction is given to stop breathing during the examination. At this time, the operator gives an instruction to the subject 20 to practice about stopping breathing. in this case,
It is also possible to give an instruction by voice actually given during the imaging. Thus, prior to imaging, the subject 20 practices several times about stopping breathing.

The operator observes this respiratory arrest,
Push button 38 at the timing when subject 20 stops breathing
push. Then, the signal is taken into the CPU 32 via the imaging control device 31, and the breathing stop time measuring device 37 starts to start time measurement. When the push button 38 is pressed again at the time when the subject 20 has stopped breathing, the time measurement ends, and the time during which the push button 38 is pressed twice, that is, the subject 20 breathes in The time during which is stopped is measured. Information on the measured time is stored in the CPU 3
2 and held.

Next, the operator sets the imaging sequence setting unit 3
In step 6, an imaging sequence to be performed is set. At this time, information relating to the measured value of the respiratory arrest time is sent to the imaging sequence setting unit 36, and setting based on the value is enabled. That is, for example, in an imaging sequence by a spiral scan, a continuous movement range (continuous imaging range) of the subject 20 while rotating the X-ray tube 12, the X-ray detector 13, and the like is calculated from the measurement time, and the range movement is performed. Then, a sequence is set such that the rotation and the movement are stopped, and the X-ray irradiation from the X-ray tube 12 is also stopped. When the subject 20 is moved stepwise and scanning is sequentially performed for each stop position to perform imaging in a plurality of cross sections, how many slices can be scanned within the measurement time described above is determined. Calculation is performed, and an imaging sequence is set so that scanning is most efficiently performed during the calculation.

The setting of the imaging sequence is performed by, for example, displaying a setting support screen on the image display device 35.
The measured value of the respiratory arrest time may be displayed on the screen, and the operator may be able to select whether to use the value as it is or to make a correction. The operator checks the time, and considers the actual state when the subject 20 stops breathing, the time required for other tests, the burden on the subject 20 in other tests, and the like. When it is determined that the correction is necessary, the correction is performed. This correction value is captured and held by the CPU 32, and is supplied to the imaging sequence setting device 36, so that the setting based on the correction value is performed.

When an imaging sequence incorporating a breathing instruction is set in this way, a command corresponding to the setting is issued from the CPU 32 to the imaging control device 31, and the imaging control device 31 sends the gantry 11 and the bed 2 in accordance with the set imaging sequence.
2 is controlled. That is, X-ray irradiation from the X-ray tube 12,
Rotation of X-ray tube 12, X-ray detector 13, etc., and top plate 21
Is controlled. When the timing to stop breathing has been reached, an instruction to stop breathing is issued automatically in synchronization with that sequence, then enters the imaging sequence for breathing stop, and when the preset breathing stop time is over, The imaging sequence for stopping breathing ends.

Here, the setting of the imaging sequence is as follows.
Although described as being performed after rehabilitation respiratory arrest and its measurement, an imaging sequence is determined in advance, then rehabilitation respiratory arrest and its measurement are performed, and the imaging sequence is corrected according to the measured value. It may be. Further, the breathing stop time measuring device 37 has been described as an independent time measuring device. However, the imaging control device 31 may have the function thereof, or the CPU 32 may perform the function. Push button 38 for indicating the respiratory hold time
It is also possible to use a specific key of a keyboard connected to the CPU 32 without specially providing such a key. In addition, specific configurations and the like can be variously modified without departing from the spirit of the present invention.

[0019]

As described above, X according to the present invention is
According to the line CT apparatus, it is possible to automatically measure and input the optimal respiratory arrest time for the subject without being too long or too short, and to perform the imaging by determining an imaging sequence based on the time. In addition, a reconstructed image free from artifacts can be efficiently obtained without forcing the subject to stop breathing for a long time.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 11 gantry 12 X-ray tube 13 X-ray detector 14 Data collection device 20 Subject 21 Top plate 22 Bed 31 Imaging control device 32 CPU 33 Image reconstruction device 34 Image memory 35 Image display device 36 Imaging sequence setting device 37 Respiration stop Time measurement device 38 push button

Claims (1)

[Claims] Means for irradiating a subject with X-rays;
Scanning means for scanning the subject with the irradiated X-rays, X-ray detecting means for making the X-rays irradiated and transmitted through the subject, and means for collecting data from the output of the X-ray detecting means Calculating means for performing processing for image reconstruction on the collected data, means for automatically measuring the respiratory arrest time performed by the subject in rehearsal, and an imaging sequence incorporating a respiratory instruction. X-rays, comprising: an imaging sequence setting unit that is determined based on the respiratory arrest time, and an imaging control unit that controls the scanning unit by the setting sequence to execute an imaging sequence incorporating a respiratory instruction. CT device.