JP3556129B2 - Ultrasound diagnostic equipment - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an ultrasonic diagnostic apparatus having a digital image signal processing unit and having a function of enlarging and displaying a subject width, and in particular, changing an effective image data range to a range set by a user for each cumulative moving distance of an ultrasonic probe. Thus, the reliability at the time of constructing an image is improved.
[0002]
[Prior art]
Conventionally, a view expansion function described in Japanese Patent Application Laid-Open No. 8-280688 is known. The test width enlarged display function predicts and estimates the moving vector amount of the ultrasonic probe from continuous B images obtained by moving the ultrasonic probe in the long axis direction as shown in FIG. Continuous B images are connected, an enlarged two-dimensional ultrasonic image is reconstructed, and an image with an enlarged subject width is displayed.
[0003]
[Problems to be solved by the invention]
However, in the above-described conventional subject width enlarged display function, the effective data size of the depth direction and the ultrasound probe subject width is fixed, and if a strong reflector such as bone exists near the ultrasound probe surface, In a portion deeper than the strong reflector, the ultrasonic waves are reflected by the strong reflector, so that the number of echoes is reduced and the image becomes dark.
[0004]
When signal processing for the subject width enlarged display function is performed using this data, the correlation with the previous frame is weakened, and the reliability in the movement amount estimation process is reduced. If the reliability is low, there is a problem that the possibility that the shape of the joined and combined enlarged images does not match the actual shape increases.
[0005]
The present invention solves the above-mentioned conventional problem, and it is possible to narrow or widen the effective image data range in the depth direction used when performing image synthesis at the position of the strong reflector that can be foreseen by the user in advance. The object of the present invention is to provide an excellent ultrasonic diagnostic apparatus capable of improving the reliability of image synthesis by changing the effective image data range for each moving distance of the cumulative ultrasonic probe and making it optimal. And
[0006]
In addition, since the test width is enlarged and displayed in real time, as shown in FIG. 7, half of the normal B image is the latest image, and the rest is the test image reconstructed from the image obtained before that. The enlarged width display image is displayed. Therefore, the portion displayed as the latest image is reduced as compared with the B image obtained by the ordinary probe scanning. When scanning the probe, the user sees the subject and the probe and cannot see the ultrasound image at the same time, so they will look at one or the other, but it is usual to scan while looking at the image. It is. Therefore, when the user is moving the probe, it is difficult to obtain information as to whether the probe surface is moving away from the subject, and there is a problem that it is difficult to scan the probe.
[0007]
In view of the above, the present invention solves the above-described conventional problem. When displaying an image by the visual field expansion function, the position information between the probe and the subject is used by simultaneously displaying the entire B image together with the image by the visual field expansion function. It is an object of the present invention to provide an ultrasonic diagnostic apparatus that can easily perform probe scanning since it can be obtained by many users.
[0008]
[Means for Solving the Problems]
In order to solve the above problem, the present invention has a user interface so that the user can change the effective image data range in the depth direction for each moving distance of the ultrasonic probe, and sets the set effective image data range. Store in memory in advance. In the test width enlarged display function, images are synthesized using the results from the ultrasonic probe movement amount prediction and estimation, which are calculated in real time, but the cumulative movement from the processing start position of the test width enlarged display function is performed. distances depending on the movement prediction of the ultrasonic probe, by varying the effective image data range used for the estimation, is obtained by improving the reliability of image construction.
[0009]
Further, by simultaneously displaying the image by the visual field expansion function and the entire B image, scanning of the probe can be facilitated.
[0010]
As described above, by changing the effective image data range to the range set by the user for each cumulative moving distance of the ultrasonic probe, the reliability at the time of constructing the image is improved. It is possible to provide an ultrasonic diagnostic apparatus that can easily perform probe scanning by simultaneously displaying the entire B image together with the enlarged width display image.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
The invention according to claim 1 of the present invention provides a scan converter unit that displays an ultrasonic echo signal obtained from an ultrasonic probe as a B image, a subject width enlargement processing unit having an image display memory, a display control unit, a display unit, And a memory in which the user sets and stores in advance the upper limit and lower limit in the depth direction used when performing image processing for each ultrasonic probe moving distance, and the user sets the upper limit and lower limit. An ultrasonic diagnostic apparatus with a user interface, in which the user sets in advance the image data range in the depth direction that is valid for each ultrasonic probe moving distance, and for each ultrasonic probe moving distance calculated in real time. in accordance with the effective image data range of the set depth, predictions of ultrasound probe movement, the prediction by performing estimation, the estimation reliability An effect that can be improved.
[0012]
In addition, the invention according to claim 2 is a memory for storing upper and lower limit values of image data in the depth direction for each ultrasonic probe moving distance set in advance by a user, and according to a cumulative moving distance of the ultrasonic probe. A test width enlargement processing unit that performs ultrasonic probe movement prediction and estimation processing using image data within the effective image data range defined by the upper and lower limits in the depth direction set by the user. Item 1. The ultrasonic diagnostic apparatus according to item 1, wherein an effective image data range in the depth direction for each ultrasonic probe moving distance is set in advance before the user performs the inspection width enlarged display function, and the image data is calculated in real time. that in accordance with the effective image data ranges that are previously set for each ultrasound probe movement distance, this to improve the reliability of the arithmetic processing by performing ultrasonic probe movement prediction, the estimation calculation It has the effect that it is.
[0013]
According to a third aspect of the present invention, in the subject width enlarged display function, the user is provided with a user interface for performing a calculation for the image processing again, and the recalculation is performed without being restricted by the calculation processing time. 3. The ultrasonic diagnostic apparatus according to claim 1, wherein the recalculation is performed without being restricted by the operation processing time, thereby improving the reliability of image construction.
[0014]
The invention according to claim 4 of the present invention has a field expansion processing unit having the images display memory, test broadening display image synthesized by Awa connecting a plurality of the B image in the field expansion processing unit and B 2. The ultrasonic diagnostic apparatus according to claim 1, wherein an image to be detected enlarged by a visual field enlargement function and a B image are simultaneously displayed in separate windows by simultaneously transferring the image to the image display memory. The obtained B image and the test width enlarged display image reconstructed from the B image by the visual field enlargement processing unit are simultaneously transferred to the display memory in the image processing unit, and the visual field enlarged display is performed on the display unit via the display control unit. Displaying the image and the B image in separate windows simultaneously has the effect of facilitating scanning of the probe.
[0015]
The invention according to claim 5 is the ultrasonic diagnostic apparatus according to claim 4, wherein the B image is simultaneously displayed as separate images in separate windows on the same monitor together with the image obtained by the visual field expansion function in which the images are combined. Since the user can obtain information such as the positional relationship between the probe and the subject, that is, whether the probe surface is separated from the subject, the scanning of the probe can be facilitated.
[0016]
According to the present invention, the upper limit value and the lower limit value of the image data in the depth direction for each moving distance of the ultrasonic probe set in advance by the user are stored in the memory in order to perform the enlarged display of the inspection width. In addition, the ultrasonic probe movement prediction and estimation processing using image data within the effective image data range defined by the upper limit value and the lower limit value in the depth direction set by the user according to the total moving distance of the ultrasonic probe. This is a method of estimating the movement of the ultrasonic probe, in which the user sets an effective image data range in the depth direction for each ultrasonic probe movement distance before performing the enlarged display of the subject width, and calculates in real time. that increase in accordance with the effective image data ranges that are previously set for each ultrasound probe movement distance, the ultrasound probe movement prediction, the reliability of the arithmetic processing by performing the estimation calculation An effect that can be.
[0019]
Hereinafter, an embodiment of the present invention will be described with reference to FIGS.
[0020]
(First Embodiment)
FIG. 1 shows a block diagram of a first embodiment of the present invention. In FIG. 1, a scan converter 1 generates a B image from an ultrasonic echo signal obtained from an ultrasonic probe, and B image data is output to a visual field enlarging processing unit 2.
[0021]
The visual field expansion processing unit 2 includes a B image Frame Buffer memory 21, an image processing unit 22 that performs movement vector calculation and image reconstruction, that is, image stitching, and a display memory unit 23, and the B image transmitted from the scan converter unit 1. The image data is temporarily stored in the B image Frame Buffer memory 21.
[0022]
The image processing unit 22 includes a CPU 221, a work memory 222, an upper limit memory 223, and a lower limit memory 224, and receives B image data from the B image Frame Buffer memory 21 and transfers the data to the image data work memory 222. Then, using the image data, the moving amount and direction of the ultrasonic probe between one frame before and the current frame image are predicted and estimated, and the image is synthesized from the result.
[0023]
The image synthesized by the image processing unit 22, that is, the enlarged display image to be detected is output to the display memory 23. The image data in the display memory 23 is displayed as an image on the display unit 4 via the display control unit 3. The upper limit memory 223 and the lower limit memory 224 are used for predicting and estimating the moving amount of the ultrasonic probe for each of the total moving distances of the ultrasonic probe that can be set in advance by the user before using the enlarged display width function. This is a memory for storing the upper limit value and the lower limit value of the effective image data range to be used. The above-described data transfer, ultrasonic probe movement prediction, estimation, and image synthesis are all performed by the CPU 221 of the image processing unit 22.
[0024]
The operation of the ultrasonic diagnostic apparatus configured as described above will be described with reference to FIG.
[0025]
FIG. 2 is a diagram also showing where an image is generated on a block according to the first embodiment of the present invention. In FIG. 2, a B image is generated in the scan converter 1. The generated B image is continuously output to the B image Frame Buffer memory 21 of the visual field expansion processing unit 2. This B image data may or may not be synchronized with the display synchronization signal. However, since the start and end timings of one frame of image data need to be recognized by the visual field enlargement processing unit 2, the B image data is displayed vertically. , The case of synchronizing with the horizontal synchronizing signal will be described. When one frame of image data is stored in the B image frame buffer memory 21, the data is transferred to the work memory 222 in the image processing unit 22.
[0026]
In the image processing unit 22, the ultrasonic probe movement amount prediction and estimation from one frame before, and image processing from the result to image joining are performed by the subject width enlargement function (FIG. 3). Here, the effective image data range in the depth direction is set in advance for each ultrasonic probe movement distance from the position of the ultrasonic probe when the subject width expansion function is started, and the upper and lower limits of the effective image data range It is assumed that data is stored in the upper limit memory 223 and the lower limit memory 224, respectively.
[0027]
When a new frame image is transferred to the work memory 222, prediction, estimation, and synthesis of an image of the ultrasound probe are performed using the image data. When predicting and estimating the moving amount of the ultrasonic probe, the upper limit value and the lower limit value data of the effective image data range corresponding to the total moving amount of the ultrasonic probe up to one frame before are extracted from the upper limit memory 223 and the lower limit memory 224. Thus, the effective image data range for performing the ultrasound probe movement prediction and estimation is determined. The movement amount is predicted and estimated using the data within the effective image data range. Then, the image joining process is performed using the result. The joined images, that is, the enlarged test width images, are output to the display memory 23.
[0028]
Since the address on the display memory 23 corresponds to the display position of the image on the display unit 4, the address on which the image is to be transferred is determined according to the image display format. The display controller 3 selects a signal source to be displayed. When the view expansion function is operating, the display memory 23 in the view expansion processor 2 is selected as a signal source. Then, the sum of the latest movement amounts is the movement amount when the next image processing is performed, and is used for calculating the effective image data range when processing the next frame image.
[0029]
FIG. 4 shows an example of a user interface for previously storing, in a memory, an upper limit value and a lower limit value indicating an effective image data range used when performing prediction and estimation of an ultrasonic probe movement set in advance by a user. FIG. 4 shows an example in the case of a maximum of 60 cm. The setting is to narrow the region where the ultrasonic signal by the strong reflector or the like becomes weak in the depth direction. Simply reducing the number of valid data for every moving distance reduces the number of usable data, which also leads to a decrease in reliability. Therefore, it is desirable to avoid providing a narrow range as much as possible.
[0030]
The memory that can change the number of data in the effective depth direction has a maximum value determined by a maximum movement amount / minimum movement amount resolution. If an interpolation calculation is performed after the ultrasonic probe movement amount is obtained, A memory of about 10 points is sufficient. Here, in the image processing unit 22, the work memory 222, the upper limit memory 223, and the lower limit memory 224 are separately described, but as described above, the upper limit memory 223 and the lower limit memory 224 are large-capacity memories. Since it is not necessary, it can be treated as a part of the work memory.
[0031]
FIG. 5 shows the operation of the image processing unit 22. First, when the B image data (80) is transferred to the work memory 222 in the image processing unit 22 (90), the previous calculation, that is, the moving amount of the ultrasonic probe obtained from the image one frame before, and the cumulative total up to that time The latest ultrasonic probe movement distance is calculated from the ultrasonic probe movement amount (95).
[0032]
Then, the effective image data range in the depth direction is obtained by interpolation from the upper limit memory 223 and the lower limit memory 224 set by the user based on the moving distance of the ultrasonic probe. If the upper limit memory and the lower limit memory can be made sufficiently large, the interpolation calculation becomes unnecessary, and the immediate value is read from the memory (91).
[0033]
The number of data for predicting and estimating the movement of the ultrasound probe in the current frame image is determined from the effective image data range, and A and B in (83) are the upper limit and the lower limit, respectively. The ultrasonic probe movement amount is predicted and estimated using the data in this range (92).
[0034]
Then, the ultrasonic probe moving amount calculation is completed, and the moving angle and the moving distance are calculated (93). As shown in the image (84), the latest B image and the B image one frame before are superimposed and image combined (94). Thus, an image (81) is obtained.
[0035]
By repeatedly performing this, the test width enlarged display image (81) is displayed in real time.
[0036]
The larger the effective image data range, the higher the reliability. However, if a strong reflector such as a bone is present where the ultrasound probe scans, the correlation between the preceding and subsequent frames at that portion is weakened, and the reliability of the ultrasound probe movement prediction and estimation stage is reduced.
[0037]
For this reason, depending on the case, it may occur that the image is rotated even though it is moved flat, or that the image is synthesized by estimating that it has moved beyond the actual moving distance.
[0038]
For this reason, when the user knows in advance that there is a factor that lowers the reliability, the reliability is improved by removing the factor that lowers the reliability.
[0039]
(Second embodiment)
In the second embodiment of the present invention, when an error occurs at the ultrasonic probe movement vector calculation stage in the real-time processing and the shape of the synthesized image is clearly different from the actual shape, the calculation of the movement vector is performed. A key for redoing the operation is provided, and when the key is pressed, recalculation for image synthesis is performed from the beginning using the image data stored in the work area.
[0040]
In that case, the part that sacrificed the calculation accuracy in order to realize the real-time processing, such as increasing the block size when detecting movement at the block level, and calculating the standard deviation of the image data, When the level of the entire image is almost constant, the size of the ultrasonic probe in the depth direction for performing image processing is reduced, so that the reliability of the estimation of the ultrasonic probe moving distance and the moving direction calculated from the image data is performed. Improve.
[0041]
According to the second embodiment of the present invention, the user sets in advance the upper limit value and the lower limit value of valid image data for each moving distance of the ultrasonic probe, and stores them in the upper limit value memory and the lower limit value memory, respectively. be able to.
[0042]
Then, in the subject width enlargement function, when predicting and estimating the moving amount and direction of the ultrasonic probe from the current frame image, for each ultrasonic probe moving distance determined so far, the upper limit memory and the lower limit memory are used. The information of the effective image data range is read, and the ultrasound probe movement prediction and estimation can be performed using the data of the range.
[0043]
By repeating this, the reliability of the ultrasound probe movement prediction and estimation required for each frame image is improved, and the frame images are joined together to reduce the error occurrence probability of the shape of the synthesized enlarged subject width image. Can be reduced.
[0044]
That is, the upper limit value and the lower limit value are set in advance so as to reduce the influence of the strong reflector, which is a foreseeable error occurrence factor, and the data is used in the image processing to improve the reliability in the image processing. be able to.
[0045]
Furthermore, by allowing recalculation to be performed after the real-time processing and improving the calculation accuracy, the influence of the strong reflector can be reduced. That is, the reliability of processing in image processing can be improved.
[0046]
(Third embodiment)
The operation in the third embodiment of the present invention will be described with reference to FIG. FIG. 6 is a diagram showing where an image is generated on a block. In FIG. 6, a B image is generated in the scan converter unit 1. The generated B image is continuously output to the B image Frame Buffer memory 21 of the visual field expansion processing unit 2. When one frame of image data is stored in the B image FrameBuffer memory 21, the image processing unit 22 performs a moving amount vector calculation and performs an image joining process using the result.
[0047]
The image processing unit 22 generally includes a microprocessor and a memory. The connected images are output to the display memory 23. At this time, the image processing unit 22 simultaneously transfers the B image data in the B image Frame Buffer memory 21 to the display memory 23.
[0048]
Since the address on the display memory 23 corresponds to the display position of the image on the display unit 4, the address on which to transfer the image is determined according to the image display format. The display controller 3 selects a signal source to be displayed. When the view expansion function is operating, the display memory 23 in the view expansion processor 2 is selected as a signal source. Therefore, the B image on the display memory 23 and the enlarged display image of the subject width are simultaneously displayed on the display unit 4. FIG. 8 shows a display example at that time.
[0049]
As described above, according to the third embodiment of the present invention, the image processing unit 22 of the visual field enlarging unit 2 generates an enlarged display image to be inspected, and the B image serving as the base image is inspected. Since the B image and the subject width enlarged display image are transferred to the display memory 23 together with the width enlarged display image, the B image and the subject width enlarged display image can be simultaneously displayed in separate windows on one monitor, and whether the probe is moving away from the subject is determined. Obtaining information such as whether the scanning of the probe can be facilitated.
[0050]
At this time, the function of the display controller unit 3 is to switch the signal source of the image. However, in the case of switching the signal source according to the display position of the image, the output of the scan converter unit 1 and the display memory 23 in the visual field enlargement processing unit are changed. Since the switching of the output is switched by the display control unit 3, it is not necessary to transfer the B image data to the display memory 23 by the image processing unit 22, and the processing time is shortened, so that the frame rate is increased.
[0051]
Also, the image display is performed on one monitor, and the windows in the monitor are displayed separately. However, the enlarged display image and the B image are output and displayed as separate image signals on a plurality of separate monitors. It is also possible. In that case, the number of the display units is required by the number of monitors, but there is an advantage that the states of the ultrasonic probe and the test portion can be easily understood.
[0052]
【The invention's effect】
As described above, according to the present invention, when calculating the ultrasound probe movement vector for each frame image in the subject width enlargement function, the range of effective image data in the depth direction used is set to the state of the subject. Therefore, the reliability of the calculated and predicted ultrasound probe movement can be improved, and the probability of occurrence of errors in image synthesis can be reduced.
[0053]
Also, in the subject width enlargement function, the B image is transferred together with the generation of the subject width enlarged display image by the image processing unit of the visual field enlargement processing unit, so that the B image and the subject width enlarged display image can be displayed simultaneously. Since the information such as the position between the probe and the subject is obtained by displaying the B image, the user can easily scan the probe.
[Brief description of the drawings]
FIG. 1 is a block diagram according to a first embodiment of the present invention;
FIG. 2 is a diagram showing a relationship between a block diagram and an image according to the first embodiment of the present invention;
FIG. 3 is a schematic view showing a function of displaying an enlarged width of a subject according to the first embodiment of the present invention;
FIG. 4 is a view showing an example of a user interface for setting an image range in the depth direction according to the first embodiment of the present invention;
FIG. 5 is a processing flowchart of an image processing unit according to the first embodiment of the present invention;
FIG. 6 is a diagram showing a relationship between a block and an image according to a third embodiment of the present invention;
FIG. 7 is a diagram showing an example of a conventional display of an enlarged display of a subject width;
FIG. 8 is a diagram showing an example of simultaneous display of a B image and an enlarged display image of a subject width according to the present invention.
[Explanation of symbols]
REFERENCE SIGNS LIST 1 scan converter unit 2 field-of-view expansion processing unit 3 display control unit 4 display unit 21 B image Frame Buffer memory 22 image processing unit 23 display memory 80 B image 81 enlarged test width image generated by field-of-view expansion processing unit 82 display control unit Fig. 84 shows the relationship between the upper limit value, the lower limit value, and the B image at the time of the latest B image and the image one frame before 85 The enlarged test width image at the display control unit and the B image 90 New frame image Data acquisition processing 91 Effective data search processing 92 Probe movement amount estimation processing 93 Moving distance calculation processing 94 Image synthesis processing 95 Next effective image data range acquisition processing 221 CPU
222 Work memory 223 Upper limit memory 224 Lower limit memory

Claims (6)

A scan converter unit for displaying a B image of an ultrasonic echo signal obtained from an ultrasonic probe, a subject width enlargement processing unit having an image display memory, a display control unit, a display unit, and image processing for each ultrasonic probe moving distance upper limit of the depth set by the user in advance to be used when having a memory save the limit value, an ultrasonic diagnostic apparatus having a user interface for the user to set the upper limit value, the lower limit. A memory for storing upper and lower limit values of image data in the depth direction for each ultrasonic probe moving distance set in advance by the user, and a depth direction set by the user according to the total moving distance of the ultrasonic probe. 2. The ultrasonic diagnostic apparatus according to claim 1, further comprising a subject width enlargement processing unit that performs ultrasonic probe movement prediction and estimation processing using image data within an effective image data range defined by an upper limit and a lower limit. 2. The ultrasonic diagnostic apparatus according to claim 1, wherein the subject width enlarged display function includes a user interface for a user to perform a calculation for image processing again, and performs the recalculation without being restricted by the calculation processing time. apparatus. Has a viewing enlargement processing unit having the images display memory, by transferring a plurality of B-pictures to be tested width enlarge images and B images to be combined by Awa connect simultaneously to the image display memory in the field expansion processing unit 2. The ultrasonic diagnostic apparatus according to claim 1, wherein the enlarged image of the subject to be inspected and the B image by the visual field enlarging function are simultaneously displayed in separate windows. The ultrasonic diagnostic apparatus according to claim 4, wherein the B image is simultaneously displayed as separate images in separate windows on the same monitor together with the image obtained by the visual field expansion function in which the images are combined. In order to perform enlarged display of the test width, the upper limit and lower limit of image data in the depth direction for each ultrasonic probe moving distance set in advance by the user are stored in the memory, and the total moving distance of the ultrasonic probe is stored. An ultrasonic probe movement estimation processing method for performing ultrasonic probe movement prediction and estimation processing using image data within an effective image data range defined by an upper limit value and a lower limit value in the depth direction set by a user in accordance with the method.

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