JPH0571254B2 - - Google Patents

Description

Detailed Description of the Invention [Technical Field of the Invention] The present invention provides image display based on echo data sequentially obtained by a transmission multi-stage focus that transmits and receives ultrasound by changing the position of a focal point on one line of ultrasound beams. The present invention relates to an ultrasonic diagnostic device that performs.

[Technical background of the invention and its problems] Transmission multi-stage focusing is a method of focusing by changing the position from shallow to deep by changing the number of transducers to transmit waves or delaying the timing of transmitting waves by each transducer by a predetermined period of time. However, even if echo data is obtained using this method, it can only obtain highly reliable echo data in the depth direction of the ultrasound beam. For this reason, in order to obtain finer images by increasing the density of pixels containing display data on the display screen, for example, in the case of a sector scan, interpolated data is embedded in the area between adjacent ultrasound beams. I was worried. This type of embedding of interpolated data is called circular interpolation, in which interpolated data is calculated based on echo data at the same depth obtained from adjacent ultrasound beams, and the calculated interpolated data is inserted between ultrasound rasters. This is done by embedding it on empty pixels.

Conventionally, when performing the above-mentioned circular interpolation based on echo data obtained by multi-stage transmission focusing, at least 2n+1 line memories are required (n is the number of transmission stages when performing multi-stage transmission focusing). . In order to sequentially store echo data for two lines of adjacent ultrasonic beams for each focal point, a number of line memories equivalent to twice the number of transmission stages is required. This is because one line memory is required to store the next echo data obtained while calculating interpolated data based on echo data for two lines of ultrasound beams.

Therefore, in conventional ultrasonic diagnostic equipment that displays images by performing the above-mentioned circular interpolation based on echo data obtained through multi-stage transmission focusing, the scale of the storage means is increased in accordance with the number of stages of transmission focusing. There was a problem that I had to do it.

[Object of the Invention] The present invention has been made in view of the above circumstances, and an object of the present invention is to store pixels from adjacent ultrasonic beams in empty pixels between ultrasonic rasters without increasing the scale of the storage means. To provide an ultrasonic diagnostic apparatus that can embed interpolated data calculated by appropriately weighting based on obtained echo data of the same depth, and can contribute to clear image display.

[Summary of the Invention] In order to achieve the above object, the present invention synthesizes a plurality of echo data at different focus positions on one ultrasound beam line obtained by transmitting and receiving ultrasound beams multiple times using a multi-stage transmission focus. a first storage means for storing echo data for each line; a second storage means for storing echo data in an image display form; and a first storage means for storing echo data in image display form; a means for transferring and storing the ultrasound data in a storage means, and a plurality of ultrasonic waves until the composite echo data of the next line is obtained every time the composite storage of a plurality of echo data for each line is completed in the first storage means; During beam transmission and reception,
With respect to two adjacent lines for which storage of synthetic echo data has been completed, interpolated data of the entire area between the addressed storage areas of the two lines in the second storage means is computed and addressed, and the address is specified, and the second storage means is stored. The ultrasonic diagnostic apparatus is provided with means for storing data in the second storage means and means for displaying an image based on the data stored in the second storage means.

[Embodiments of the Invention] Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing a device according to an embodiment of the present invention. One embodiment of the device described here is
Echo data is obtained while transmitting multi-stage focusing is performed by sector scanning, and an image is displayed in B mode based on this echo data and circular interpolation data calculated from this echo data.

What is indicated by 1 in the figure is a transducer group in which a plurality of ultrasonic transducers are arranged in parallel, and this transducer group generates an ultrasonic beam with a desired deflection angle and focusing position. part 2, a detection part 3 that detects the echo of the transmitted ultrasound when the transducer group 1 receives it; an A/D conversion part 4 that converts the echo data detected by the detection part 3 into digital;
A first storage unit that stores the echo data digitally converted by the A/D converter 4 for each ultrasound beam line.
storage means 5, an address designation section 12 that designates addresses on the display screen for the echo data and circular interpolation data stored in the first storage means 5; A second storage means (hereinafter simply referred to as frame memory) 6 for storing data and circular interpolation data, and an output for temporarily storing echo data read from the frame memory 6 in accordance with the horizontal scan on the display screen. a buffer memory 7, a D/A converter 8 for converting the output from the output buffer memory 7 into analog;
A television monitor (hereinafter simply referred to as a TV monitor) 9 is provided that displays an image on a display screen based on the output from the A conversion section 8.

The first storage means 5 has a capacity that can store echo data for three lines of ultrasound beams, and is composed of a first line memory 5A, a second line memory 5B, and a third line memory 5C. It is structured as follows. Each line memory 5A, 5B, 5C
The system stores echo data for each ultrasound beam line, which is a combination of echo data with different focal point positions on one ultrasound beam line. A data synthesizing means (hereinafter simply referred to as a line memory controller) 10 is provided for synthesizing echo data with different focal point positions on one line of ultrasound beams sequentially obtained by storing the echo data in each line memory 5A, 5B, and 5C. It is being Each time the echo data for one line of ultrasound beams synthesized via this line memory controller 10 is stored in one line memory, it is transferred to the frame memory 6. During the start-to-end interval of each transfer operation that sequentially transfers the echo data stored in the frame memory 6 to the frame memory 6, the echo data of the adjacent ultrasonic beams stored in any two line memories are transferred to the frame memory 6. Calculation control means 11 is provided for calculating circular interpolation data in the region between ultrasound beams and storing it in the frame memory 6.

Here, the configuration of the calculation control means 11 will be explained in further detail. For example, if the echo data of the k-th ultrasound beam line is stored in the first line memory 5A and the echo data of the k+1-th ultrasound beam line is stored in the second line memory 5B, then The echo data of the th ultrasonic beam line will be stored in the third line memory 5C while being synthesized, but during this synthesis storage operation, the echo data stored in the second line memory 5B will first be stored in the second line memory 5B. is transferred to the frame memory 6, and after the transfer is completed, circular interpolation data is calculated based on the echo data stored in the first line memory 5A and the second line memory 5B, and this data is stored in the frame memory 6. This arithmetic storage operation is completed before the combined storage of the echo data in the third line memory 5C is completed and the transfer of the echo data to the frame memory 6 is started. Note that the echo data used in the calculation of interpolation data are sequentially erased in order to synthesize and store the next echo data. The above configuration includes, for example, a calculation weighting controller 11A that determines a value to be weighted on echo data when calculating circular interpolation data, and the weighting value determined by the calculation weighting controller 11A and echo data that are read out sequentially from the line memory. Specifically, it includes a calculation unit 11B that calculates circular interpolation data based on the calculation unit 11B.

Here, the contents of the calculation by the calculation control means 11 will be explained. FIG. 2A shows an ultrasonic sector image consisting of a plurality of ultrasonic rasters on the display screen of the TV monitor 9 when circular interpolation is not performed. For example, if the kth and k+1st ultrasound rasters are
When pixelized on the display screen of the TV monitor 9, it can be shown as shown in FIG. 2B (the intersection of each grid corresponds to a pixel). In this figure, the ● marks are pixels that make up the ultrasonic raster image. 〇 is an empty pixel that has no data, and the horizontal distribution of empty pixels between two ultrasonic rasters depends on the sector angle, for example, as shown in Fig. 2C.
The distribution area shown in is taken, and the number of empty pixels increases as the area approaches the tail. That is, the number of horizontal empty pixels between two ultrasound rasters is 0 in the S ₀ region, 1 in the S ₁ region, 2 in the S ₂ region, 3 in the S ₃ region, and 4 in the S ₄ region. It is distributed as follows.

The arithmetic control means 11 obtains circular interpolation data to be embedded in the empty pixels. For example, if the set of echo data possessed by the k-th ultrasound raster is A, and the echo data possessed by the k+1-th ultrasound raster is B, then the empty pixels between both ultrasound rasters are explained in Fig. 2C. Distribution area S ₁ ,
Circular interpolation data is obtained by weighting as shown in FIG. 2D according to the number of empty pixels in S ₂ , S ₃ , S ₄ , . . . , Sn. In addition, when obtaining circular interpolation data, echo data A, which is subject to weighting,
For B, those having the same depth, that is, those located at the same position along the tail direction of the ultrasonic raster are used. Furthermore, since the distribution state of empty pixels differs depending on the sector angle, that is, the position of the ultrasonic raster, as shown in Figure 2C, the positions V, W, X, and Y of empty pixels, which are the starting points for circular interpolation, are It is controlled so that it can vary variably according to the sector angle so as to match the distribution shown in Figure C.

Next, the operation of the apparatus of the above embodiment will be explained.

First, transmission multi-stage focusing is performed in two stages, one for near region N and one for far region F. As shown in Fig. 3, the apex of the sector is B ₀ , the boundary between both regions N and F is B ₁ , and the ultrasonic raster Let the numbers of the ultrasonic beam lines corresponding to the above be 0, 1, 2, .

FIG. 4 is a time chart for explaining the operation of the apparatus of the above embodiment. Ultrasonic waves are transmitted via the ultrasonic transducer group 1 and the wave transmitter 2 according to the ultrasonic rate. This wave transmission is performed along the ultrasound beam lines numbered 0 to number n shown in Fig. 3, and is performed to the near region N and far region F for each ultrasound beam line. . First, when the ultrasonic wave for the near region N is transmitted to the ultrasonic beam line number 0, the echo signal 0N is sent to the first line memory 5A via the detection section 3 and A/D conversion section 4. It will be sent. At this time, the line memory controller 10 stores only the echo data of the portion corresponding to the near region N of the echo signal 0N in the first line memory 5A. Next, when the ultrasonic wave for the far region F is transmitted to the ultrasonic beam line number 0, the echo signal 0F is similarly transmitted to the first line via the detection section 3 and the A/D conversion section 4. It will be sent to memory 5A. At this time, the line memory controller 10 outputs the echo signal 0.
Only the echo data of the portion of F corresponding to the far region is stored in the first line memory 5A following the already stored echo data of the near region. The echo data synthesized and stored in the first line memory 5A in this way is stored in the arithmetic control section 11.
The echo data is transferred to the frame memory 6 after receiving the address specification on the display screen by the address specification unit 12 (the echo data thus transferred is indicated by D{0} in FIG. 4). When this echo data D{0} is being transferred to the frame memory 6, the same multi-stage transmission focus as described above is performed for the number 1 ultrasound beam line.
The data are combined and stored on the second line memory 5B. After the combined storage is completed, the echo data of the near area N and far area F are addressed and transferred to the frame memory 6 (the echo data transferred in this way is indicated by D{1} in FIG. 4). ). Then, while this echo data D{1} is being transferred to the frame memory 6, the same multi-stage transmission focus as described above is performed on the number 2 ultrasound beam line, and the near area N and the front are focused on the third line memory 5C. The echo data of area F will be synthesized and stored, but after the transfer of the echo data D{1} is completed, until the echo data synthesized and stored on the third line memory 5C is transferred to the frame memory 6 ( At the interval time T of D{2} in FIG. 4, the echo data transferred to the frame memory is
The arithmetic control unit 11 generates an ultrasonic raster corresponding to the ultrasonic beam line number 0 and an ultrasonic raster number 1.
The circular interpolation data to be interpolated on the empty pixel located between the ultrasonic raster corresponding to the ultrasonic beam line of is calculated, and the calculated circular interpolation data is stored in the frame memory 6 (in this way, The circular interpolation data stored in Figure 4 is
C ₀ {denoted by f(0.1)}). Furthermore, this circular interpolation data
C ₀ {f(0.1)} is stored in response to the address designation on the display screen by the address designation section 12 . The same operation will be performed sequentially for the ultrasonic beam lines numbered 3 and onwards. That is, the first line memory 5A stores the combined information for the number 3 ultrasound beam line.
Until the above echo data is transferred to the frame memory (the transferred echo data is transferred to D{3} in Figure 4).
) within the interval time T, the interpolated data
C ₀ {f(1.2)} (Circular arc to be interpolated on empty pixels located between the ultrasound raster corresponding to the ultrasound beam line number 1 and the ultrasound raster corresponding to the ultrasound beam line number 2) interpolated data)
is calculated and stored, and the echo data D{4},
..., D{n} and circular interpolation data C ₀ {f(2.3)},
..., C ₀ {f(n-1.n)} is memorized.

Echo data D{0},..., D{n} and circular interpolation data C ₀ {f(0.1)},..., C ₀ {f(n-1) are stored in the frame memory 6 with specified addresses.
n)} is sent to the output buffer memory 7 along with the horizontal scan of the TV monitor 9, and is sent to the D/
The image is displayed on the TV monitor 9 via the A converter 8 .

As described above, the present embodiment apparatus combines the echo data of the near region N and the far region F for one ultrasonic beam line and stores the combined echo data in one line memory. When the echo data of the main ultrasound beam line is combined and stored, the echo data to be combined and stored next is based on the above two echo data within the free time (interval time T) until it is transferred to the frame memory. Since the circular interpolation data is calculated and stored, the capacity of the first storage means 5 is sufficient to store echo data for three lines of ultrasonic beams, and the size of the storage means can be reduced. can do. Furthermore, since circular interpolation data is embedded in empty pixels between ultrasound rasters, a clear image can be displayed without reducing the number of frames (however, the number of frames may be reduced due to multiple transmission stages).

Note that the above-mentioned embodiment is merely an example, and it goes without saying that various modifications can be made within the scope of the gist of the present invention. Although the above embodiment describes the case where sector scan is performed, the present invention is not limited to this, but is applicable to various scans such as linear scan, trapezoidal scan, and convex scan. Further, although the device of the above embodiment performs only B-mode display, it is also possible to use a device with an M-mode or D-mode display function added. In this case, another line memory is provided for D mode display or M mode display, or the line memories 5A to 5C in the first storage means 5 are controlled to display the B mode image and the M mode image or the B mode image. Mode image and D
It is necessary for the arithmetic control means 11 to perform the calculation appropriately so as not to calculate interpolated data based on the combination with the mode image. Furthermore, the method of weighting the interpolated data is not limited to the method shown in FIG. 2D, and any appropriate weighting is possible.

[Effects of the Invention] As detailed above, in the ultrasonic diagnostic apparatus of the present invention, data obtained from adjacent ultrasonic beams to empty pixels between ultrasonic rasters can be stored without increasing the scale of the storage means. This has excellent effects such as being able to embed interpolated data calculated with appropriate weighting based on echo data at the same depth, and contributing to clear image display.

[Brief explanation of drawings]

FIG. 1 is a configuration block diagram showing an apparatus according to an embodiment of the present invention, FIG. 2 is an explanatory diagram of the calculation contents by the calculation control means, and FIG. 2A is an explanatory diagram showing a sector image when circular interpolation is not performed. Figure B is an explanatory diagram when ultrasound rasters are pixelized on the display screen, Figure C is an explanatory diagram showing the horizontal distribution of empty pixels between ultrasound rasters, and Figure D is an example of weighting. FIG. 3 is a schematic explanatory diagram showing a sector image for explaining the operation of the apparatus of one embodiment, and FIG. 4 is a time chart for explaining the operation of the apparatus of one embodiment. 5...first storage means, 6...second storage means, 1
0...Data synthesis means, 11...Arithmetic control means.

Claims (1)

[Scope of Claims] 1. A first memory that combines a plurality of echo data with different focus positions on one ultrasound beam line obtained by transmitting and receiving ultrasound beams multiple times using a transmission multi-stage focus and stores it for each line. means; second storage means for storing echo data in an image display form; means for addressing the synthetic echo data stored in the first storage means and transferring and storing it in the second storage means; Every time the first storage means completes the combined storage of a plurality of echo data for each line, the combined echo data is stored during multiple ultrasound beam transmissions and receptions until the combined echo data of the next line is obtained. With respect to two adjacent lines for which storage has been completed, interpolation data of the entire area between the addressed storage areas of the two lines in the second storage means is calculated, addressed, and stored in the second storage means. An ultrasonic diagnostic apparatus comprising: means for displaying an image based on the data stored in the second storage means. 2. The interpolated data is obtained by calculating interpolated data between two lines between the synthetic echo data of the latest line for which synthetic storage has been completed and the synthetic echo data for the line for which synthetic storage has been completed one line before,
2. The interpolation data is addressed and stored in the second storage means after the latest synthesized echo data that has been synthesized and stored is addressed and stored in the second storage means. Ultrasound diagnostic equipment.