JPH06154204A - X-ray tomographic camera - Google Patents

Abstract

PURPOSE:To provide an X-ray tomographic camera which enables the restarting thereof quickly during a system down attributed to a power failure or the like while allowing the resumption of a scanning after the restarting from immediately before the system down occurs. CONSTITUTION:This camera which performs a helical scanning is provided with a scan information storage means 3 to store scan information of a subject and a raw data storage means 4 to store the history of scanning and raw data collected continuously by scanning during the scanning of the subject at a specified time interval. Then, scanning continuation means 2, 3 and 4 are arranged to start up equipment alone minimum necessary for the continuation of the scanning of the subject in the starting up of the system after the system down when the system down occurs and continues the scanning so as to collect data partially duplicating the raw data stored in the raw data storage means into the raw data storage means immediately before the system down.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a helical scan type X-ray tomography apparatus, and more particularly, to an X-ray tomography apparatus at the time of stoppage due to system down caused by power failure or the like.
The present invention relates to a restart method for a line tomography apparatus.

[0002]

2. Description of the Related Art An X-ray tomographic imaging apparatus irradiates an object with X-rays, detects X-rays transmitted through the object, and detects X-rays of the object.
Take a line tomographic image. This X-ray tomographic imaging apparatus has a scan method that can continuously collect data, which is a method called helical scan. Since the helical scan method can image the subject in a shorter time than the normal single scan method, an image with less influence of movement due to respiration, especially in the abdomen, can be obtained. Further, since the data of the subject is continuously obtained, it has a feature that an image of an arbitrary slice section can be obtained.

However, when the system stops during continuous scanning of the helical scan due to some cause, for example, a power failure, etc. (hereinafter referred to as system down),
Since the scanning stops when the system goes down, the continuity of data cannot be maintained. Therefore, the continuity of the raw data is interrupted, and the scanning must be restarted from the beginning.

Re-scanning as described above increases the burden on the patient and the operator and causes a time loss, and in addition, the X-ray dose to be irradiated on the subject increases. In particular, in imaging using a contrast agent, the damage caused by re-scanning is extremely large.

[0005]

As described above, in the conventional X-ray tomographic imaging apparatus, when a system down occurs during continuous scanning of the helical scan due to some cause, for example, a power failure or the like. However, when the system goes down, the scanning is stopped and the continuity of the data cannot be maintained. Therefore, there is a problem that the scanning has to be restarted from the beginning.

The present invention has been made in view of the above circumstances, and X when a system is down due to a power failure or the like.
The X-ray tomography apparatus can be quickly restarted, and the scan after the restart can be restarted immediately before the system goes down.
An object is to provide a line tomographic imaging apparatus.

[0007]

The present invention has taken the following means in order to solve the above problems.

The present invention is a helical scan type X-ray tomographic imaging apparatus, wherein scanning information storage means for storing predetermined scanning information including scanning conditions of the subject and continuous scanning of the subject. Raw data storage means for storing scan history and raw data collected by the scan at predetermined time intervals, and when system down occurs, continue scanning of the subject at system startup after system down Scanning in which only the minimum necessary equipment is started up and scanning is continued in the raw data storage means so as to collect data that partially overlaps the raw data stored in the raw data storage means immediately before the system goes down. And means for continuing.

[0009]

As a result of taking the above-mentioned means, the following effects occur.

In the helical scan type X-ray tomographic imaging apparatus, scanning information storage means for storing predetermined scanning information including scanning conditions of the subject, and a history of scanning continuously during the scanning of the subject and Raw data storage means for storing the raw data collected by scanning at a predetermined time interval, and the minimum necessary to continue scanning the subject when the system is started after the system goes down when the system goes down. Scanning continuation means for starting up only a limited device and continuing scanning so as to collect data partially overlapping with the raw data stored in the raw data storage means immediately before the system goes down in the raw data storage means, As a result, even if the system stops during continuous helical scan, the system is immediately restarted, scanning is restarted from the stopped position, and continuous It can be obtained specific collection data. In addition, since the scanning can be restarted from the stop position, it is not necessary to restart the scanning from the beginning, the X-ray irradiation amount is reduced, the operator's burden is reduced, and the patient's burden and time are reduced when the system stops during the scanning. Reduce loss.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

The X-ray tomographic imaging apparatus is configured to irradiate the subject with X-rays, detect the X-rays transmitted through the subject, and obtain an X-ray tomographic image of the subject. Here, as a scanning method of the subject, there is a method called helical scanning. Helical scanning is an X-ray tomographic image of an arbitrary cross section of a subject, which is obtained by continuously moving the subject while the X-ray generator and the X-ray detector are rotating and scanning the subject in a spiral shape. This is a scan method that can be obtained. In the explanation below,
Perform only for helical scan. FIG. 1 shows a schematic block diagram of the X-ray tomographic imaging apparatus of the present invention.

The X-ray tomographic imaging apparatus of the present invention includes a data collecting unit 1 for collecting raw data of a subject, a CPU 2 for controlling the entire X-ray tomographic imaging apparatus, and data transfer between the units. A memory 3 having functions such as a buffer, a storage device 4 for storing raw data, a reconstructing device 5 for reconstructing an X-ray tomographic image from the raw data, and a display device for displaying the reconstructed image or raw data. 6 and a dialogue unit 7 for inputting / outputting to / from the outside. The respective units are connected to each other by a data bus to exchange data. Details of each part are as follows.

The data acquisition unit 1 includes a scanner (not shown) (including a drive unit for driving an X-ray generator and an X-ray detector).
And a bed or the like on which the subject is placed. The data processing unit 1 A / D-converts the raw data obtained by the helical scan and then outputs it to a data processing unit (not shown). The data processed by the data processing unit is output to another device such as the CPU 2 or the memory 3 via the data bus.

The CPU 2 has a function of controlling the entire X-ray tomographic imaging apparatus. Since the CPU 2 also has a function of performing input / output between the X-ray tomographic imaging apparatus and the outside, a dialogue unit 7 for performing input / output between the apparatus and the outside is connected so that dialogue with the operator can be performed. ing.

The memory 3 is a general-purpose memory used as a data buffer when recording collected data in a storage device 4 which will be described later, and as a buffer, a work area, etc. for transferring data between units. Is. Further, by attaching an uninterruptible device to the memory 3, it can be used as a backup memory. In this embodiment, the main memory 3 is used as a reference memory when the system is restarted when the system is down.

A magnetic disk device is generally used as the storage device 4, and the storage device 4 stores reconstructed X-ray tomographic image data, raw data, various systems, data files, and the like. The reconstruction device 5 reconstructs an X-ray tomographic image from raw data. The display device 6 displays scanning conditions, raw data, or an X-ray tomographic image obtained by reconstruction. The operation of the apparatus configured as above will be described.
The following information is stored in the memory 3 before or immediately after the start of the scanning by the helical scan. -Scanning conditions (scanning time, X-ray output, slice thickness, bed moving speed, etc.)-X-ray irradiation start angle-Scanning start time-Start address of the storage device 4 that stores the data collected by scanning Note that the storage device The area of 4 is reserved at consecutive addresses.

Next, raw data collected while scanning is sequentially stored in the storage device 4. A predetermined amount, for example, 36
Every time the storage of raw data for 0 ° is completed normally, the bed position at that time and the address of the storage device 4 are updated on the memory 3. In this way, raw data is collected sequentially.

It is assumed that the system goes down during the collection of raw data as described above. System down generally occurs during the collection of raw data. Figure 2
The case where the system down occurs during the collection of the fifth data is shown. In this case, the fifth data is not completely collected, that is, the address of the storage device 4 on the memory 3 has not been updated, so the fifth data currently being collected is immediately discarded. At this time, as described above, the uninterruptible power supply (not shown) is attached to the memory 3, and the contents stored in the memory 3 are retained when the system goes down. Startup from system down is performed as follows.

The operator uses a dedicated switch or the like to start up the system in an emergency start-up mode different from normal start-up. Due to this emergency start-up, operations such as normal start-up of all equipment are not performed, only the equipment necessary for continuing the operation is started up,
Operation continues. Therefore, the operation can be restarted with the minimum startup time. Devices that are not started up at this point are, for example, a display device, a reconstruction device, an image processing device, a peripheral device other than a disk, and tasks related to these.

After the system is started up in the emergency mode, preparations are made for restarting the operation based on the information stored in the memory 3. Specifically, the following operations are automatically performed.

(A) Return the bed to the position where the system down occurs. However, in practice, run-up and overlap scan are required, so return before that. Also, the moving speed of the bed is reset. (B) Rotate the gantry and set the X-ray exposure conditions.

(C) Slice thickness and other scanning conditions are set. However, if there is a guarantee that the slit thickness, tilt angle, etc. will not change due to system down, it is also possible to omit or check only in order to shorten the time.

When the preparation for continuing the scanning is completed as described above, READY is displayed, and the scanning is started by the scanning start switch of the operator. In this case, as shown in FIG. 2, it is possible to collect data from the fifth data that could not be collected. However, there is a possibility that the continuity of the data cannot be maintained due to the body movement of the patient.
For this reason, as shown in FIG. 3A, for the purpose of maintaining the continuity of the data, the collected raw data has overlapping portions of the raw data before and after the system down occurs, for example, data n and n ′. , Is provided. For example, in FIG. 2, since the system is down at the time of collecting the fifth data, n is the fourth data before the occurrence of the system down. In addition, n'is the fourth data after the system is started after the system is down. Thereafter, as shown in FIG. 3B, by performing data processing for providing data continuity, smoothing of raw data (n and n ′ in this case) before and after the system down occurs. Here, an extra area of the storage device 4 is reserved in advance for this smoothing.

By the above, even when a system down occurs due to a power failure or the like, the X-ray tomographic imaging apparatus is started up in a minimum time and collected before the system down occurs. The raw data can be used almost as is to continue the scan.

When the system is started up in this mode, some devices have not been started up. However, for these devices, if the system is started up again in the normal start-up mode when all the scanning is completed. Good.

Data such as the status during scanning is stored in the memory 3.
However, the present invention is not limited to this. For example,
When a part of the storage device 5 is specially allocated and the emergency mode is started up, the data stored in the special address allocated to the storage device 5 may be read and restarted. Besides, the present invention is not limited to the above-described embodiments, and it goes without saying that various modifications can be made without departing from the scope of the present invention.

[0028]

According to the present invention, the following effects can be obtained.

In the X-ray tomography apparatus of the helical scan type, a scan information storage means for storing predetermined scan information including the scan condition of the subject, a scan history continuously during the scan of the subject, and Raw data storage means for storing the raw data collected by scanning at a predetermined time interval, and the minimum necessary to continue scanning the subject when the system is started after the system goes down when the system goes down. Scanning continuation means for starting up only a limited device and continuing scanning so as to collect data partially overlapping with the raw data stored in the raw data storage means immediately before the system goes down in the raw data storage means, As a result, even if the system stops during continuous helical scan, the system is immediately restarted, scanning is restarted from the stopped position, and continuous It can be obtained specific collection data. Since the scanning can be restarted from the stop position, it is not necessary to restart the scanning from the beginning, so the X-ray irradiation dose decreases and
The burden on the operator is reduced, and the burden and time loss on the patient when the system stops during scanning is reduced.

[Brief description of drawings]

FIG. 1 is a schematic block diagram of an X-ray tomographic imaging apparatus of the present invention.

FIG. 2 is a diagram showing a data discarding state when a system down occurs during scanning.

FIG. 3 is a diagram showing how data is smoothed.

[Explanation of symbols]

1 ... Data collection unit, 2 ... CPU, 3 ... Memory, 4 ... Storage device, 5 ... Reconstruction device, 6 ... Display device, 7 ... Dialogue unit.

Claims (1)

[Claims] 1. A helical scan type X-ray tomographic imaging apparatus, comprising: scan information storage means for storing predetermined scan information including scan conditions of the subject; and scan information storage means for continuously scanning the subject. Raw data storage means for storing the raw data collected by history and scanning at a predetermined time interval, and for continuing the scanning of the subject when the system is down and the system is started after the system down. Scanning in which only the minimum necessary equipment is started up and scanning is continued in the raw data storage means so as to collect data that partially overlaps the raw data stored in the raw data storage means immediately before the system goes down. An X-ray tomographic imaging apparatus comprising: a continuation unit.