JP2009172030A - Ultrasonic diagnostic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the display of object tissue moving inside an image. <P>SOLUTION: A transmission circuit 12 controls a probe 10 so as to successively repeat scanning patterns in three directions corresponding to a center direction, a left direction and a right direction over a plurality of scanning timings, and a reception circuit 14 forms reception signals corresponding to the scanning pattern at the scanning timing for each scanning timing. The reception signals successively formed for the respective scanning timings are stored in a memory 16. A composition processing part 18 forms the image data of a display image including the object tissue by combining the plurality of reception signals corresponding to the plurality of scanning patterns. When combining the plurality of reception signals, the plurality of reception signals obtained at the scanning timings different from each other for at least one scanning pattern are combined. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an ultrasonic diagnostic apparatus, and more particularly to an ultrasonic diagnostic apparatus that synthesizes a plurality of received signals corresponding to a plurality of scanning patterns.

  A technique called spatial compound is known in which an ultrasonic beam is scanned with a plurality of scanning patterns corresponding to different directions, and a plurality of received signals corresponding to the plurality of scanning patterns are combined to form an ultrasonic image. (For example, refer to Patent Document 1). Spatial compounding can reduce noise such as speckle caused by ultrasonic interference, for example.

  In the spatial compound, for example, a three-direction scanning pattern corresponding to the central direction, the left direction, and the right direction is repeated over a plurality of times (scanning timings), and reception corresponding to the scanning pattern at that time is received at each time. A signal is obtained. Then, the reception signals corresponding to the scanning patterns in the three directions obtained over three times (scanning timings) are combined to form a combined image.

  Therefore, for example, the reception signal of the scan pattern in the central direction obtained at time 1 is used for forming a composite image corresponding to time 1 and corresponds to two times 2 and 3 after time 1. It is also used for forming composite images. Then, at time 4 after time 3, the reception signal of the scanning pattern in the central direction is updated.

Japanese Patent No. 3730147

  As described above, in the spatial compound, for example, the received signal of one scanning pattern obtained at a certain time is updated after being used at the next two times. For this reason, when a composite image of a moving object is formed by conventional spatial compounding, for example, the object moves greatly until the reception signal of one scanning pattern is updated, and the movement of the object in the composite image is awkward There are concerns about such phenomena as being visible.

  In addition, when the probe is moved with respect to a fixed object, the same phenomenon is concerned. For example, in the case of a blood vessel or the like that has a black spot in the image, if the probe is moved relative to the blood vessel, the black spot in the composite image will appear to flutter.

  Under such circumstances, the inventor of the present application has repeatedly researched and developed an improved technique related to spatial compound. In particular, we focused on the display technology of the target tissue that moves in the image.

  The present invention has been made in the course of its research and development, and its purpose is to improve the display of the target tissue moving within the image.

  In order to achieve the above object, an ultrasonic diagnostic apparatus according to a preferred aspect of the present invention includes a probe that transmits / receives ultrasonic waves to / from a diagnostic region including a target tissue and a plurality of scanning patterns corresponding to different directions. A transmitter that controls the probe so as to scan the ultrasonic beam within the diagnostic region; a receiver that forms a received signal corresponding to each of a plurality of scanning patterns by processing a signal obtained from the probe; An image forming unit that forms image data of a display image including a target tissue by synthesizing a plurality of reception signals corresponding to a scanning pattern, and the image forming unit is configured to synthesize a plurality of reception signals. A plurality of received signals obtained at different scanning timings for at least one scanning pattern are synthesized.

  According to the above aspect, since a plurality of reception signals obtained at different scanning timings for at least one scanning pattern are combined, the target tissue is compared with a case where only the reception signals obtained at one scanning timing are used. It becomes possible to reduce the phenomenon associated with large movement. For example, it is possible to reduce a phenomenon in which the motion of the target tissue looks awkward in the display image, a phenomenon in which a blackened portion such as a blood vessel flutters in the display image, and the like.

  In a preferred aspect, the image forming unit is characterized in that the plurality of received signals obtained at different scanning timings are weighted according to the scanning timing and combined.

  In a desirable mode, the transmitting unit controls the probe so as to sequentially repeat a scanning pattern in three directions corresponding to the central direction, the left direction, and the right direction over a plurality of scanning timings, and the receiving unit includes each scanning timing. Each time, a reception signal corresponding to the scanning pattern at the scanning timing is formed, and the image forming unit generates the reception signal at one scanning timing corresponding to the scanning pattern in the reference direction and the scanning pattern in the other two directions. It is characterized in that five reception signals corresponding to five consecutive scanning timings composed of reception signals at two scanning timings corresponding to each are synthesized.

  The present invention improves the display of the target tissue that moves within the image. For example, according to a preferred aspect of the present invention, it is possible to reduce a phenomenon in which the movement of the target tissue looks awkward in the display image, a phenomenon in which a blackened portion such as a blood vessel appears in the display image, It becomes possible.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the drawings. FIG. 1 shows a preferred embodiment of an ultrasonic diagnostic apparatus according to the present invention, and FIG. 1 is a functional block diagram showing the overall configuration thereof.

  The probe 10 is an ultrasonic probe that transmits and receives ultrasonic waves to and from a diagnostic region including a target tissue. The target tissue is, for example, a tissue in a living body, a cavity in the tissue, a blood vessel, a blood flow, a tumor, or the like, but may be a tissue other than these. The probe 10 in this embodiment is, for example, a linear probe and includes a plurality of vibration elements arranged in a straight line. However, the probe 10 is not limited to a linear probe, and may be, for example, a convex probe.

  The transmission circuit 12 outputs a transmission signal corresponding to each of the plurality of vibration elements included in the probe 10. The transmission circuit 12 applies a delay process or the like corresponding to the vibration element to the transmission signal of each vibration element. The transmission signal output from the transmission circuit 12 is supplied to each vibration element of the probe 10. That is, the transmission circuit 12 functions as a transmission beam former, and each vibration element vibrates in accordance with the transmission signal supplied from the transmission circuit 12, thereby forming an ultrasonic transmission beam and scanning control of the transmission beam. The

  The reception circuit 14 forms a reception beam based on signals obtained from a plurality of vibration elements included in the probe 10. The receiving circuit 14 performs a delay process or the like corresponding to the vibration element on the signal of each vibration element, and adds signals obtained from the plurality of vibration elements. That is, the reception circuit 14 functions as a reception beam former, and forms an ultrasonic reception beam by performing, for example, phasing addition processing on signals output from the plurality of vibration elements. In this way, reception signals along the reception beam are collected from the entire diagnosis area.

  Each unit in the ultrasonic diagnostic apparatus shown in FIG. 1 is controlled by the control unit 30. For example, the transmission circuit 12 and the reception circuit 14 are controlled by the control unit 30, and the probe 10 is controlled via the transmission circuit 12. In the present embodiment, the probe 10 is controlled so as to scan the ultrasonic beam in the diagnostic region with a plurality of scanning patterns corresponding to different directions, and a received signal corresponding to each of the plurality of scanning patterns. The receiving circuit 14 is controlled so as to form

  That is, the transmission circuit 12 controls the probe 10 so as to sequentially repeat three-direction scanning patterns corresponding to the central direction, the left direction, and the right direction over a plurality of scanning timings, and the receiving circuit 14 A reception signal corresponding to the scanning pattern at the scanning timing is formed. Received signals formed one after another at each scanning timing are stored in the memory 16. The memory 16 is, for example, a cine memory.

  The synthesis processing unit 18 forms image data of a display image including the target tissue by synthesizing a plurality of reception signals corresponding to a plurality of scanning patterns. When combining a plurality of received signals, signals (data) corresponding to the same pixel position are combined (weighted addition). For example, when the synthesis processing unit 18 reads the data of the reception signal from the memory 16, a read address is set as appropriate, and data corresponding to the same pixel position is read. Note that when data of a received signal is written in the memory 16, data corresponding to the same pixel position may be written at addresses corresponding to each other.

  The display processing unit 20 performs display processing on the image data (composite image data) formed in the synthesis processing unit 18. For example, the coordinate system of image data is converted from a coordinate system suitable for an ultrasonic beam to a coordinate system suitable for image display. That is, the display processing unit 20 has a function as a digital scan converter. Then, a display image corresponding to the image data processed in the display processing unit 20 is displayed on the display unit 22.

  As described above, in the present embodiment, image data of a display image including a target tissue is formed by combining a plurality of reception signals corresponding to a plurality of scanning patterns. In synthesizing a plurality of received signals, a plurality of received signals obtained at different scanning timings for at least one scanning pattern are synthesized. Therefore, the synthesis process in this embodiment will be described in detail below. In the following description, the reference numerals in FIG. 1 are used for the configuration (portion) shown in FIG.

  FIG. 2 is a diagram for explaining the synthesis processing by the ultrasonic diagnostic apparatus of FIG. In FIG. 2, times (T1 to T9) indicated on the horizontal axis are scanning timings. A received signal (A, D, G) obtained by a central scan pattern is shown along the horizontal axis indicating time, and similarly obtained by a left scan pattern along the horizontal axis showing time. The received signals (B, E, H) and the received signals (C, F, I) obtained by the rightward scanning pattern are shown.

  As described with reference to FIG. 1, the transmission circuit 12 controls the probe 10 to sequentially repeat a scan pattern in three directions corresponding to the center direction, the left direction, and the right direction over a plurality of scan timings, The reception circuit 14 forms a reception signal corresponding to the scanning pattern at the scanning timing for each scanning timing.

  As a result, for example, as shown in FIG. 2, a reception signal A corresponding to the scanning pattern in the central direction is formed at time T1, and a reception signal B corresponding to the scanning pattern in the left direction is formed at time T2. A reception signal C corresponding to the scanning pattern in the right direction is formed. Then, at time T4, the scan pattern returns to the central direction again, and the reception signal D is formed. In this way, the scanning patterns in the three directions corresponding to the central direction, the left direction, and the right direction are repeated, and reception signals corresponding to the respective scanning patterns are successively formed.

  Then, as described with reference to FIG. 1, a plurality of received signals corresponding to a plurality of scanning patterns are combined in the combining processing unit 18. At the time of the synthesis process, a reception signal at one scanning timing corresponding to the scanning pattern in the reference direction and a reception signal at two scanning timings corresponding to the scanning patterns in the other two directions are continuously formed. Five received signals corresponding to the five scanning timings are synthesized.

  For example, as shown in FIG. 2, five received signals (A to E) obtained from time T1 to T5, which are five consecutive scanning timings, are combined and combined at time T5 ′ corresponding to time T5. An image T5 ′ is formed. The composite image T5 ′ is formed with reference to the scanning pattern in the right direction. That is, the reception signal C at time T3 corresponding to the rightward scanning pattern is included as a reference. The composite image T5 'includes a reception signal A at time T1 corresponding to the scanning pattern in the center direction and a reception signal D at time T4, and further, a reception signal B at time T2 corresponding to the scanning pattern in the left direction. And the reception signal E at time T5.

  In synthesizing a plurality of received signals, the plurality of received signals are weighted according to the scanning timing. For example, with respect to the composite image T5 ′, the weight value 1 is associated with the reception signal C at time T3 corresponding to the reference scanning pattern in the right direction. Then, the received signals A, B, D, and E are weighted according to the temporal distance from the time T3.

  That is, with respect to the reception signal A and the reception signal D corresponding to the scanning pattern in the center direction, a relatively heavy weight value 2/3 is associated with the reception signal D that is temporally close to the time T3, and the time T3 A relatively light weight value 1/3 is associated with the received signal A that is far from the received signal A.

  Similarly, with respect to the reception signal B and the reception signal E corresponding to the scanning pattern in the left direction, a relatively heavy weighting value 2/3 is associated with the reception signal B that is temporally close to the time T3. A relatively light weight value 1/3 is associated with the received signal E that is far in time from T3.

  In this way, when the composite image T5 ′ is formed, a reception signal synthesis process expressed as “A * 1/3 + D * 2/3 + B * 2/3 + E * 1/3 + C” is performed. Since the coefficient (total weighting value) is 3 as a result of the synthesis process, the result of the synthesis process may be divided by 3 so as to cancel the coefficient.

  The synthesized image T6 ′ at time T6 ′ corresponding to time T6 is also formed by synthesizing five received signals corresponding to five consecutive scanning timings. For example, the composite image T6 ′ is based on the reception signal D of the scanning pattern in the central direction at time T4, and is weighted according to the temporal distance from time T4. Then, in forming the composite image T6 ′, a reception signal synthesis process expressed as “D + B * 1/3 + E * 2/3 + C * 2/3 + F * 1/3” is performed.

  By the way, when forming the composite image T7 ′, the reception signal expressed as “D * 2/3 + G * 1/3 + E + C * 1/3 + F * 2/3” is combined to form the composite image T8 ′. The received signal expressed as “D * 1/3 + G * 2/3 + E * 2/3 + H * 1/3 + F” is synthesized, and “G + E * 1/3 + H * 2/3 + F” is formed in forming the synthesized image T9 ′. A received signal combining process expressed as “* 2/3 + I * 1/3” is performed. In these combining processes, the weight values are linearly distributed according to the temporal distance from the reference time, but the distribution of the weight values is not limited to the linear distribution.

  As described above, in the present embodiment, two received signals obtained at different scanning timings are combined for each of the two scanning patterns of the three scanning patterns. Therefore, compared to the case where only the received signal obtained at one scanning timing is used, for example, the target tissue moves greatly compared to the case where only the received signal A, the received signal B, and the received signal C are used. The accompanying phenomenon can be reduced. For example, it is possible to reduce a phenomenon in which the motion of the target tissue looks awkward in the display image, a phenomenon in which a blackened portion such as a blood vessel flutters in the display image, and the like.

  As mentioned above, although preferred embodiment of this invention was described, embodiment mentioned above is only a mere illustration in all the points, and does not limit the scope of the present invention. The present invention includes various modifications without departing from the essence thereof.

1 is a functional block diagram showing an overall configuration of an ultrasonic diagnostic apparatus according to the present invention. It is a figure for demonstrating the synthetic | combination process by the ultrasonic diagnosing device of FIG.

Explanation of symbols

  10 probe, 12 transmitting circuit, 14 receiving circuit, 16 memory, 18 composition processing unit, 20 display processing unit, 22 display unit.

Claims (3)

A probe for transmitting and receiving ultrasound to and from a diagnostic region including the target tissue;
A transmitter for controlling the probe so as to scan the ultrasonic beam in the diagnostic region with a plurality of scanning patterns corresponding to different directions;
A reception unit that forms a reception signal corresponding to each of the plurality of scanning patterns by processing a signal obtained from the probe;
An image forming unit that forms image data of a display image including a target tissue by combining a plurality of reception signals corresponding to a plurality of scanning patterns;
Have
The image forming unit synthesizes a plurality of reception signals obtained at different scanning timings with respect to at least one scanning pattern in synthesizing a plurality of reception signals.
An ultrasonic diagnostic apparatus. The ultrasonic diagnostic apparatus according to claim 1,
The image forming unit weights and combines the plurality of received signals obtained at different scanning timings according to scanning timing;
An ultrasonic diagnostic apparatus. The ultrasonic diagnostic apparatus according to claim 2,
The transmission unit controls the probe to sequentially repeat a scanning pattern in three directions corresponding to the central direction, the left direction, and the right direction over a plurality of scanning timings,
The receiving unit forms a reception signal corresponding to a scanning pattern at each scanning timing for each scanning timing,
The image forming unit includes a reception signal at one scanning timing corresponding to a scanning pattern in a reference direction and a reception signal at two scanning timings corresponding to scanning patterns in the other two directions. Synthesizing five received signals corresponding to five scanning timings;
An ultrasonic diagnostic apparatus.

Images