JPH01131645A - Image reconstruction and display apparatus - Google Patents

Abstract

PURPOSE:To perform enlarged display in real time, by mounting an image memory means for applying convolution processing to pre-processed image data to store the processing result and an enlarging and reconstructing means for applying back projection processing to the image data taken out from said memory means. CONSTITUTION:Pre-processed image data are subjected to convolution processing by a reconstruction part 6 to be stored in a disk file 11. These data are subjected to back projection processing by the reconstruction part 6 to obtain a reconstructed image which is, in turn, stored in an image memory 18 as the original image. At the same time, this image is transmitted to a frame memory 17 to be stored therein and displayed on a display part 16 as a matrix having a desired size. As mentioned above, since the projection data in usual reconstruction processing is stored and back projection is performed by utilizing said data to apply enlarging reconstruction processing, a wasteful time can be saved and enlarged display can be performed in real time.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to an image reconstruction display device that reconstructs collected image data and displays the image on a display unit.

(Prior art) After reconstructing image data collected in an X-ray CT system and displaying the image on a display unit, a part of the region of interest (ROI') of this image is enlarged and reconstructed and displayed. It is being used for diagnosis. FIG. 2 shows an outline of such an X-ray CT system, in which X-ray absorption data from X-rays emitted from the X-ray tube 1 toward the subject 2 is detected by the detector 3, and then The data is stored in the data collection unit 4. Such data immediately after collection is called pure raw data, and this pure raw data is subjected to desired preprocessing such as log conversion, scatter correction, wedge correction, etc. by the preprocessing unit 5, and is converted into content called raw data. It will be done. The raw data subjected to such pre-processing is sent to the reconstruction unit 6.
The image is subjected to desired reconstruction processing, filed as an image, and displayed on the display unit as necessary.

Here, as shown in FIG.
．． It consists of a back projection unit 8, which multiplies the raw data obtained by the preprocessing unit 5 by a reconstruction function 9, repeats the calculation in the convolution unit 7, and then performs the calculation in the back projection unit 8. Configuration processing is performed. When the same region of the subject is to be diagnosed, convolution processing is performed by multiplying by the same reconstruction function, but when different regions are to be diagnosed, the convolution processing is performed so that the display is easy to observe. Convolution processing is performed by changing the constituent functions.

While the image that has been reconstructed in this manner is displayed on the display section, an ROI is set in any part of the image, and enlarged reconstruction processing is performed and enlarged display is performed. When the enlarged reconstruction processing is performed without changing the reconstruction function, the convolution processing and the back projection processing are repeated in the same way as when performing the reconstruction processing.

(Problems to be Solved by the Invention) Conventionally, when performing enlarged reconstruction processing after reconstruction processing, projection processing and back projection processing are repeatedly performed, which wastes time. There's a problem. That is, in the reconstruction unit 6 shown in FIG. 3, most of the time is spent on convolution processing and back projection processing, but repeating such processing to perform enlarged reconstruction is This means that approximately the same time as is normally required for reconstruction is required for the image to be displayed, and enlarged display cannot be performed in real time.

The present invention has been made in response to the above-mentioned problems.
The object of the present invention is to provide an image reconstruction display device that performs enlarged display in real time.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, the present invention provides image storage means for performing convolution processing on preprocessed image data and storing the results, and The image forming apparatus is characterized by comprising an enlarged reconstruction means for performing back projection processing on the image data taken out from the image data storage means based on the ROI.

(Function) Preprocessed image data subjected to convolution processing is stored, and when performing enlarged reconstruction processing, this stored image data is taken out and back projection processing is performed. This makes it possible to save time required for convolution processing, and to perform enlarged reconstruction processing only by performing back projection processing.

Therefore, the enlarged image can be displayed in less time than normally required for reconstruction, so that the enlarged image can be displayed in real time.

(Embodiment) FIG. 1 is a block diagram showing an embodiment of the image reconstruction display device of the present invention. The image reconstruction unit 6 has a configuration as shown in FIG. Data input/output is performed. For example, pure raw data imitated by an X-ray CT device is input from the data collection unit 4 . The image reconstructed by the image reconstruction unit 6 is stored in the image memory 18 via the data pathco 0, and is roughly stored in the frame memory 17.
is transferred and stored. An image is stored in the frame memory 17 as a display image, and the image is stored as it is on the display unit 16.
will be displayed.

All projections of the preprocessed raw data (image data) that have been subjected to extraction processing in the projection unit 7 of the reconstruction unit 6 are stored in a disk file 11, and are retrieved by the reconstruction unit 6 as needed and subjected to desired processing. will be held. C.P.
The U (central processing unit) 13 is composed of a dedicated microprocessor, and controls the entire control operation according to a program installed in advance. The memory 12 operates as a buffer memory and stores data necessary to perform various processes, such as C.
It is used to temporarily store the program of the PU 13 and data processed by the reconfiguration unit 6.

The ROI controller 14 includes ROI input means such as a trackball, joystick, mouse, etc., and when the image in the frame memory 17 is displayed on the display section 16 as it is, the ROI controller 14 changes the image according to the operation of the ROI input means. An ROI can be set at any position on the screen. ROI information from ROI controller 14 is sent to zoom controller 15 and image memory 18. The zoom controller 1 to the roller 15 are connected to the reconstruction unit 6 according to the ROI information.
control to perform reconstruction processing on a region corresponding to the ROI. When the reconstruction process of the reconstruction unit 6 is completed, the zoom controller 15 reads out this image and sends it to the RO.
The corresponding area of the frame memory 17, for example, the 178 part, is replaced by the I information.

As a result, the region 17a based on the ROI setting is enlarged and displayed on the display section 16. In this way, the size of the area to be enlarged and displayed, that is, the size of the matrix, can be arbitrarily selected according to the ROI setting. By operating the ROI input means of the ROI controller 14, the region 17a
can be moved to any position, and thereby the display section 16
The upper enlarged display area also moves. When the ROI is moved in this way, the image memory 18 in which the original image is stored each time transfers the image of the original area after the movement on the frame memory 17 to the frame memory 17 and restores the original image. Rewrite to image. As a result, even if the ROI moves to an arbitrary position, the original image is always displayed in areas other than the ROI. Note that it is also possible to prepare a buffer memory in the reconstruction unit 6 and to store all the projection data after the convolution process.

Next, the operation of this embodiment will be explained.

The preprocessed image data is subjected to convolution processing by the reconstruction unit 6 and then stored in the disk file 11 . Alternatively, it is stored in a buffer 7 memory provided in the reconstruction unit 6. Next, these data are subjected to back-projection processing by the reconstruction unit 6 to obtain a reconstructed image, and this image is stored in the image memory 18 as an original image. At the same time, this image is transferred to the frame memory 17 and stored, and displayed on the display unit 16 in a matrix of a desired size, for example, 512×512.

In this state, by operating the ROI input means of the ROI controller 14, the ROI to be enlarged and reconstructed on the displayed image is
When I is set, this ROI is displayed on the screen □. At the same time, this ROI information is sent to the zoom controller 15,
Based on the control of this zoom controller 15, the reconstruction unit 6
reads the preprocessed image data stored in the disk file 11 and performs arithmetic processing for back projection. The time required for backprojection processing is proportional to the 71 helix size. For example, if a 128×128 matrix is selected according to the ROIKU specification, and 600 projections are selected and can be processed at 24 (ns) per pixel, the total back projection processing time TB is as follows.

Te=25X10-9X128X128X600=0
．． 246 (seconds) The image thus enlarged and reconstructed by back projection processing is read out by the zoom controller 15 and replaced with the corresponding area 17a@ffi on the image in the frame memory 17. As a result, the area 17a is enlarged and displayed on the display section 16.

According to this embodiment, when performing enlarged reconstruction processing after reconstruction processing, image data subjected to projection calculation processing during reconstruction processing is stored in a disk file, etc., and this data is used during enlarged reconstruction processing. Since the back projection calculation process is performed using the , the time required for the projection calculation process can be saved.

Therefore, since enlarged reconstruction can be performed by performing only back projection processing, enlarged display can be performed in real time. In addition, by selecting a small matrix size to be enlarged and reconstructed, the back projection processing time can be roughly shortened, making it possible to further shorten the calculation speed.

Effects of the Invention As described above, according to the present invention, projection data in normal re-groove acid treatment is stored, and this data is used to perform back projection to perform enlarged reconstruction processing. Therefore, wasted time can be saved and enlarged display can be performed in real time.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the image reconstruction display device of the present invention, FIG. 2 is a block diagram showing an X-ray CT system, and FIG. 3 is a block diagram showing the configuration of the main parts of FIG. 2. be. 5... Preprocessing section, 6... Reconstruction section, 7... Projection section, 8... Back projection section, 11... Disk file, 14... ROI controller, 15... Zoom Controller, 17... Frame memory, 18... Image memory. Agent Patent Attorney Norihiro Ken Takeshi Konfuji Figure 2 Figure 8

Claims (1)

[Claims] After reconstructing the collected preprocessed image data and displaying the image on the display unit, the preprocessed image data is subjected to convolution processing and the result is displayed in an image reconstruction display device that enlarges and displays a part of the image. An image reconstruction display device comprising: an image data storage means for storing image data; and an enlarged reconstruction means for performing back projection processing on image data retrieved from the image data storage means based on a preset ROI.