KR100869496B1 - Ultrasound imaging system and method of forming ultrasound image - Google Patents

Abstract

The present invention provides a system and method for transmitting and focusing an ultrasound signal at a designated focal point different in position and number depending on an object, and receiving a reflected ultrasound signal to form an ultrasound image. The system and method stores information of a specific focusing point and common focusing point for each object, transmits an ultrasonic signal to a common focusing point or a designated focusing point of an object, and reflects a signal of an ultrasonic signal transmitted to a common focusing point of an object Receive a second signal to form a first received signal, receive a reflected signal of an ultrasonic signal transmitted to a designated focal point of the object to form a second received signal, form a base image of the object based on the first received signal, The basic image is analyzed to determine a designated focal point of the object, and an ultrasound image signal is formed based on the focused second received signal.

Ultrasound, number of focal points, designation, object

Description

ULTRASOUND IMAGING SYSTEM AND METHOD OF FORMING ULTRASOUND IMAGE

1 is a block diagram showing the configuration of an ultrasonic imaging system according to an embodiment of the present invention.

2 is a schematic view showing a scanning line and a coordinate system together with a transducer and an acoustic lens of an ultrasonic transceiver.

3 is a schematic diagram showing a common focal point arranged on each scan line.

4 is an explanatory diagram showing a divided region, an object, and a boundary point obtained by dividing a base image in a transmission axis direction of an ultrasonic signal according to an embodiment of the present invention;

Fig. 5 is a graph showing the number of boundary points of each partition and the relative size of ^-1 (total contrast mean-partial contrast mean) ^-1 .

FIG. 6 is a graph illustrating a grade of each divided area of FIG. 5 as a sum of a first reference value and a second reference value. FIG.

7 is a schematic diagram showing a focusing point assigned to a divided area of a reference grade or higher.

8 is an explanatory diagram showing a partition, an object, and a boundary point obtained by dividing a base image in a transmission side direction of an ultrasound signal according to an embodiment of the present invention;

FIG. 9 is a graph showing the number of boundary points of each partition of FIG. 8 and the relative size of (full contrast mean-partial contrast mean) ⁻¹ ; FIG.

FIG. 10 is a graph illustrating a grade of each divided area of FIG. 8 as a sum of a first reference value and a second reference value. FIG.

11 is a schematic diagram showing a designated focusing point determined by dividing a base image in a transmission axis direction and a lateral direction of an ultrasonic signal on a scan line;

12 and 13 are block diagrams showing the configuration of an ultrasound imaging system according to an embodiment of the present invention.

The present invention relates to the field of ultrasonic imaging, and more particularly, to an ultrasonic imaging system and method for forming an ultrasonic image using a designated focusing point reflecting a characteristic of an object.

The ultrasound imaging system uses ultrasound to show the internal structure of the object in a non-destructive and non-invasive manner. The ultrasonic imaging system includes a probe, a beamformer, an analog-to-digital converter, and an image processor. A probe for transmitting and receiving an ultrasonic signal includes a plurality of transducers for mutually converting an ultrasonic signal and an electrical signal. Each transducer of the probe generates an ultrasonic signal separately, and several transducers simultaneously generate an ultrasonic signal. The ultrasonic signal transmitted from each transducer is reflected at the discontinuous surface (reflector surface) of the acoustic impedance inside the object. Each transducer converts the individually reflected ultrasonic signals into electrical received signals. The analog-digital converter converts the received signal into a digital signal, and the beamformer focuses on the transmission and reception by considering the focal point of the ultrasonic signal and the position of each transducer. The image processor forms ultrasound image data based on the focused received signal.

In the conventional ultrasound imaging system, the ultrasound signal is transmitted and received at a focus point that is constantly set regardless of the shape of the object without considering the characteristics of the object. Accordingly, there is a disadvantage in that an ultrasound signal is focused on a focusing point not located on the object, and thus transmission and reception of unnecessary signals and data processing are required.

The present invention provides an ultrasound imaging system and method for forming an ultrasound image using a designated focusing point reflecting a characteristic of an object.

The ultrasound imaging system according to an embodiment of the present invention transmits and focuses an ultrasound signal to a designated focal point having a different number and position according to an object, and receives an ultrasound signal reflected from the object to form an ultrasound image.

The ultrasound imaging system may include: a focal point information storage unit configured to store information on the designated focal point for each object and common focal point information; Transmitting an ultrasonic signal to a common focal point or the designated focal point of the object, receiving a reflected ultrasound signal from the object to form a received signal, and receiving the reflected signal of the ultrasonic signal transmitted to the common focal point of the object A transceiver configured to receive and form a first received signal, and receive a reflected signal of the ultrasonic signal transmitted to a designated focal point of the object to form a second received signal; A designated focus point determiner configured to form a base image of the object based on the first received signal, and determine a designated focus point of the object by analyzing the base image; An image processor configured to form an ultrasound image signal based on the focused second received signal; And a display unit for displaying the ultrasound image.

The ultrasound imaging system may include a focusing point information providing unit for providing information of a focusing point for which a position and a number are designated for each object; A transmitter / receiver for transmitting an ultrasound signal to a designated focal point of the object and receiving a reflected ultrasound signal from the object to form a received signal; An image processor configured to form an ultrasound image signal based on the focused reception signal; And a display unit for displaying an ultrasound image formed based on the ultrasound image signal.

The focal point information providing unit provides designated focal point information stored in a computer readable recording medium. The focusing point information providing unit is a wired / wireless communication unit which receives and provides the focusing point information from the designated focusing point information providing server separated from the ultrasound imaging system.

The designated focal point information providing server forms a base image of the object based on the reflected ultrasound signal obtained by transmitting an ultrasonic signal to a common focal point having a constant position and number regardless of the type of the object, and analyzes the base image. A designated focus point determiner configured to determine a designated focus point of the object; And a storage unit for storing the information of the designated focal point.

The designated focusing point determiner may divide the base image into a plurality of areas based on the location of the common focusing point, detect a boundary point of the object in each divided area, and based on the number of detected boundary points, a first reference value. Calculate a difference between the average contrast value of the base image and the average contrast value of each of the divided regions, set a second reference value based on the calculated difference, and based on the first reference value and the second reference value It is determined whether to specify a focal point of each divided area. The designated focusing point determiner divides the base image in at least one of a transmission axis direction and a transmission side direction of the ultrasound signal.

The transceiver includes a plurality of transducers, and the ultrasound imaging system includes: a transmission beam forming unit configured to provide a transmission focusing delay for focusing a transmission ultrasound signal on the common focal point or the designated focal point of an object; The apparatus may further include a reception beam forming unit configured to provide a reception focus delay for focusing the first or second reception signal.

The ultrasound image shaping method according to the embodiment of the present invention transmits and focuses an ultrasound signal to a designated focusing point having a different position and number depending on an object, and receives a reflected ultrasound signal to form an ultrasound image. More specifically, the object stores the information on the designated focusing point and the common focusing point for each object, transmits an ultrasonic signal to the common focusing point or the designated focusing point of the object, receives and receives the reflected ultrasonic signal from the object Forming a signal, receiving a reflected signal of the ultrasonic signal transmitted to a common focal point of the object to form a first received signal, receiving a reflected signal of the ultrasonic signal transmitted to a specified focal point of the object, and 2 forming a received signal, forming a base image of the object based on the first received signal, analyzing the base image to determine a designated focus point of the object, and based on the focused second received signal An ultrasonic image signal is formed. The base image is divided into a plurality of areas based on the location of the common focal point, a boundary point of the object is detected in each divided area, a first reference value is set based on the number of detected boundary points, and the base image Calculates a difference between an average contrast value and an average contrast value of each of the divided regions, sets a second reference value based on the calculated difference, and focus points of the respective divided regions based on the first reference value and the second reference value Determine whether it is specified. The base image is divided into at least one of a transmission axis direction and a transmission side direction of the ultrasonic signal.

The present invention also provides a computer readable recording medium having stored thereon a program for performing the above-described ultrasound image forming method.

The ultrasound imaging system according to an embodiment of the present invention transmits and focuses an ultrasound signal at a designated focal point having a different position and number depending on an object, and receives a reflected ultrasound signal to form an ultrasound image.

First Example

Referring to FIG. 1, the ultrasound imaging system 100 includes a focal point information storage unit 10, a hand-deliver 20, a transmission beam forming unit 30, a reception beam forming unit 40, and a designated focal point determining unit ( 50, an image processor 60, and a display 70.

The focal point information storage unit 10 stores information of a specific focal point for each object and common focal point information. The subject may be a heart, liver, fetus, etc., but is not limited thereto, and all types of ultrasound diagnosis may be subjects. The designated focal point is a focal point whose position and number differ by object. In an embodiment of the present invention, the designated focusing point of each object is determined in the designated focusing point determination mode. The common focal point is a focal point set to have the same number of positions regardless of the object.

The transceiver 20 transmits an ultrasound signal to a common focal point or a designated focal point of the object, and receives a reflected ultrasound signal from the object to form a received signal. The transceiver 20 receives the reflected signal of the ultrasonic signal transmitted to the common focal point of the object to form a first received signal, and receives the reflected signal of the ultrasonic signal transmitted to the specified focal point of the object to receive the second received signal. To form. As shown in FIG. 2, the transceiver 30 may be implemented as a probe including a plurality of transducers 31 for converting ultrasonic signals and electrical signals. The ultrasonic signal from each transducer is transmitted and received to the object along the axial direction. FIG. 2 shows a lateral direction and an elevation direction, which is a cross-sectional thickness direction of the object, in a direction perpendicular to the axial direction.

The transmission beam forming unit 30 provides a transmission focus delay amount for focusing an ultrasound signal at each focal point in consideration of a common focal point or a designated focal point of the object and the position of each transducer. The reception beam forming unit 40 provides a reception focusing amount for focusing the first reception signal or the second reception signal in consideration of each focal point and the position of the transducer.

The reception beam forming unit 40 focuses the second received signal with a focusing delay amount considering the designated focusing point and the position of the transducer.

The designated focus point determiner 50 forms a base image of the object based on the first received signal, and analyzes the base image to determine the designated focus point of the object.

The image processor 60 forms an ultrasound image based on the second received signal. The image processor 60 may serve as a system controller for controlling the focal point information storage unit 10, the transmission beam forming unit 30, the reception beam forming unit 40, and the designated focal point determining unit 50. . Of course, depending on the implementation of the system, the image processor 60 and the system controller may be separately configured. The display unit 70 displays an ultrasound image.

Hereinafter, the function of each structure in a designated focusing point determination mode is demonstrated concretely.

In the designated focal point determination mode, the transceiver 20 transmits an ultrasonic signal to the common focal points FC01 to FC7 on each scan line SL0 to SL6 as shown in FIG. Form a receive signal.

The designated focusing point determiner 50 forms a base image of the object as shown in FIG. 4 based on the first received signal focused by the reception beam forming unit 40, and generates a plurality of baseline images based on the location of the common focal point. Split into areas of As shown in FIG. 4, the designated focusing point determiner 50 may divide the base image into a plurality of areas A0 to A7 in the transmission axis direction of the ultrasonic signal. The designated focusing point determiner 50 detects the boundary point EP of the object OB in each divided area A0 to A7 in order to efficiently designate a focusing point in the area where the object exists.

The boundary point can be detected using a change in the brightness value by the differential operator. In an embodiment of the present invention, an edge mask is detected using an edge mask such as Sobel, Prewitt, Robert, The Laplacian of Gaussian, or Canny mask. . Alternatively, the boundary point may be detected from a difference of eigen values using a structure tensor.

The designated focusing point determiner 50 sets the first reference value based on the number of detected boundary points EP. The first reference value may be the number of boundary points themselves or a rating determined according to the number of boundary points. In addition, the designated focus point determiner 50 calculates a difference between the average contrast value (the overall average contrast value) of the base image and the average contrast value (the partial contrast average) of each of the divided areas A0 to A7, and calculates the difference. Set a second reference value based on. The second reference value may be defined as a total contrast mean-partial contrast mean) ^-1 , or a rating determined according to the magnitude of (full contrast mean-partial contrast mean) ^-1 . Fig. 5 shows the number of boundary points of each of the divided regions A0 to A7 together with the relative size of (full contrast mean-partial contrast mean) ^-1 .

The designated focusing point determiner 50 determines whether to specify a focusing point of each divided area based on the first reference value and the second reference value. The designated focusing point determiner 50 determines whether to specify the focusing point of each divided area based on the sum of the first reference value and the second reference value or the sum of the first reference value and the second reference value reflecting the weight. For example, the designated focusing point determiner 50 determines the grade of each region by the sum of the first reference value and the second reference value (or the weighted sum), and focuses only on the partitions corresponding to the grade of the reference grade or higher. Specifies. FIG. 6 shows the class of each divided area determined according to the sum of the first reference value and the second reference value, and FIG. 7 schematically shows a focusing point assigned to the divided area above the reference class on the scan line. As described above, the designated focusing point determiner 50 determines whether to specify a focusing point by reflecting not only the number of boundary points but also the average contrast of the entire base image and the average contrast of each segmented area, thereby determining the segmentation area of FIGS. An error in which a focal point is not specified in an area where the object is located but the number of boundary points is relatively small, such as A4 and A5, can be avoided.

According to another exemplary embodiment of the present invention, the designated focusing point determiner 50 may divide the base image in the transmission side direction of the ultrasonic signal to obtain the divided regions B0 to B6 shown in FIG. 8. Similarly, the boundary point EP of the object OB is detected in each of the divided regions B0 to B6, and the average contrast value (the overall average contrast value) of the base image and the average contrast value (the average contrast value of each of the segment regions B0 to B6) are detected. The difference between the partial contrast averages) is calculated, and a second reference value is set based on the calculated difference to determine whether to specify each divided area B0 to B6? Focus point based on the first reference value and the second reference value. FIG. 9 shows the number of boundary points of each of the divided areas B0 to B6 and the relative size of (the total contrast mean-the partial contrast mean) ^-1 , and FIG. 10 shows the respective divisions determined according to the sum of the first reference value and the second reference value. The grades of the regions B0 to B6 are shown.

FIG. 11 schematically shows a designated focal point determined by dividing a base image in a transmission axis direction and a lateral direction of an ultrasound signal on a scan line. In accordance with the above-described determination of the focusing point, each scanline does not have a designated focusing point AF on the scanlines SL0, SL1, and SL6 of FIG. 11, but does not have a designated focusing point AF to obtain a received signal of the corresponding scanline. One focal point SF is designated at an arbitrary position.

Hereinafter, the function of each component in the ultrasound image forming mode will be described in detail.

The transmission beam forming unit 30 provides a transmission focus delay amount for focusing an ultrasonic signal to each designated focusing point in consideration of the designated focusing point AF and the position of each transducer as shown in FIG. 7 or 11. The transceiver 20 transmits an ultrasonic signal to the designated focusing point AF, receives the reflected ultrasonic signal, and forms a second received signal. The reception beam forming unit 40 focuses the second received signal with a focusing delay amount considering the designated focusing point and the position of the transducer. The image processing unit 60 forms an ultrasound image based on the focused second received signal. . The display unit 70 displays the ultrasound image formed by the image processor 60.

As shown in FIG. 3, the effect of the present invention can be intuitively understood by comparing a certain common focal point without distinguishing an object from the number of designated focal points of FIG. 7 or 11 determined according to an embodiment of the present invention. That is, according to the present invention, by designating a designated focusing point for each object in consideration of the characteristics of the object, the number of transmission focusing points can be reduced to shorten an ultrasonic signal transmission / reception time and a signal processing time.

2nd Example

Referring to FIG. 12, the ultrasound imaging system 300 according to an exemplary embodiment of the present invention may include a designated focusing point information providing unit 310 for providing information of a focusing point for which a position and a number are designated for each object, and a designated focusing point of an object. A transmitting / receiving unit 320 for transmitting an ultrasonic signal to the target, receiving a reflected ultrasonic signal from the object to form a received signal, an image processing unit 360 for forming an ultrasonic image signal based on the received signal, and based on the ultrasonic image signal And a display unit 370 for displaying the formed ultrasound image.

The designated focal point information providing unit 310 reads and provides designated focal point information stored in a computer readable recording medium. Computer-readable recording media include ROM, RAM, CD-ROM, magnetic tape, floppy disk, optical data storage device.

Referring to FIG. 13, the designated focal point information providing unit 310 may be implemented as a wired / wireless communication unit that receives and provides designated focal point information from the focal point information storage server 400 separated from the ultrasound imaging system 300. .

The designated focal point information storage server 400 analyzes a basic image obtained by transmitting an ultrasound signal to a common focal point having a constant position and number regardless of the type of the object, and determines a designated focal point of each object. 410 and a storage unit 420 for storing information of the designated focal point.

Like the designated focal point determiner 50 of FIG. 1, the designated focal point determiner 410 divides the base image into a plurality of areas based on the location of the common focal point. The designated focusing point determiner 410 may divide the base image in at least one of a transmission axis direction and a transmission side direction of the ultrasonic signal. The designated focus point determiner 410 detects the boundary point of the object in each divided area, sets the first reference value based on the number of detected boundary points, and compares the average contrast value of the base image with the average contrast value of each divided area. The difference is calculated, a second reference value is set based on the calculated difference, and whether to specify a focal point of each divided area is determined based on the first reference value and the second reference value.

The third Example

The ultrasound image shaping method according to the embodiment of the present invention transmits and focuses an ultrasound signal at a designated focal point having a different position and number depending on an object, and receives a reflected ultrasound signal to form an ultrasound image.

To this end, information on the designated focusing point and the common focusing point for each object are stored, and an ultrasound signal is transmitted to the common focusing point or the designated focusing point of the object. The reflection ultrasound signal is received from the object to form a reception signal.

In order to determine a designated focal point, a reflection signal of an ultrasound signal transmitted to a common focal point of an object is received to form a first received signal. A basic image of the object is formed based on the first received signal. The target image is determined by analyzing the base image. More specifically, the base image is divided into a plurality of areas based on the location of the common focal point. The base image may be divided into at least one of a transmission axis direction and a transmission side direction of the ultrasonic signal.

The boundary point of the object is detected in each segment, the first reference value is set based on the number of detected boundary points, the difference between the average contrast value of the base image and the average contrast value of each segment is calculated, and the calculated difference is calculated. A second reference value is set as a reference, and it is determined whether to specify a focal point of each divided area based on the first reference value and the second reference value.

A second reception signal is formed by receiving a reflection signal of an ultrasound signal transmitted to a designated focal point of the object to form an ultrasound image. An ultrasound image signal is formed based on the second received signal.

Although the ultrasound image forming methods according to the present invention have been described through specific embodiments, the methods may be embodied as computer readable codes on a computer readable recording medium. Computer-readable recording media include all kinds of recording devices that store data that can be read by a computer system. Examples of computer-readable recording media include ROM, RAM, CD-ROM, magnetic tape, floppy disks, optical data storage devices, and the like, which are also implemented in the form of carrier waves (for example, transmission over the Internet). Include. The computer readable recording medium can also be distributed over network coupled computer systems so that the computer readable code is stored and executed in a distributed fashion. In addition, functional programs, codes, and code segments for implementing the ultrasound image forming methods according to the present invention can be easily inferred by programmers in the art to which the present invention belongs.

It is to be understood that the above described embodiments are merely illustrative of some of the various embodiments employing the principles of the present invention. It will be apparent to those skilled in the art that various modifications may be made without departing from the spirit of the invention.

By determining the designated focusing point for each object in consideration of the characteristics of the object, it is possible to reduce the number of transmission focusing points to shorten the transmission / reception time of the ultrasonic signal and to efficiently focus the beam to obtain an optimized image.

Claims (14)

delete A focal point information storage unit for storing information on the designated focal point and the common focal point information different in position and number depending on the object; Transmitting an ultrasonic signal to a common focal point or the designated focal point of the object, receiving a reflected ultrasonic signal from the object to form a received signal, and receiving a reflected signal of the ultrasonic signal transmitted to the common focal point of the object A transmission / reception unit configured to form a first reception signal, and receive a reflection signal of the ultrasound signal transmitted to a designated focal point of the object to form a second reception signal; A designated focus point determiner configured to receive the first received signal to form a base image of the object, and to analyze the base image to determine a designated focal point of the object; An image processor configured to receive the second received signal and form an ultrasound image signal; And Display unit for displaying the ultrasound image Ultrasound imaging system comprising a. A focal point information providing unit for providing information of a focal point designated for each object by a position and number; A transmitter / receiver for transmitting an ultrasound signal to a designated focal point of the object and receiving a reflected ultrasound signal from the object to form a received signal; An image processor configured to receive the received signal and form an ultrasound image signal; And A display unit for receiving the ultrasound image signal and displaying an ultrasound image Ultrasound imaging system comprising a. The method of claim 3, The focal point information providing unit, An ultrasound imaging system, providing designated focal point information stored on a computer readable recording medium. The method of claim 3, The focal point information providing unit, And a wired / wireless communication unit configured to receive and provide the focusing point information from the designated focusing point information providing server separated from the ultrasonic imaging system. The method of claim 5, The designated focusing point information providing server, Regardless of the type of the object, a base image of the object is formed by using a reflected ultrasound signal obtained by transmitting an ultrasound signal to a common focal point having a constant position and number, and the base image is analyzed to determine a designated focal point of the object. A designated focus point determiner; And And a storage unit for storing information of the designated focal point. The method according to claim 2 or 6, The designated focus point determiner, The base image is divided into a plurality of areas based on the location of the common focal point. Detecting a boundary point of the object in each divided area, setting a first reference value based on the number of detected boundary points, Calculate a difference between the average contrast value of the base image and the average contrast value of each segment, set a second reference value based on the calculated difference, And determining whether to specify a focus point of each of the divided regions using the first reference value and the second reference value. The method of claim 7, wherein The designated focus point determiner, And dividing the base image in at least one of a transmission axis direction and a transmission side direction of the ultrasonic signal. The method of claim 8, The transceiver includes a plurality of transducers, The ultrasonic imaging system, A transmission beam forming unit configured to provide a transmission focusing delay for focusing a transmission ultrasound signal on the common focal point or the designated focal point of the object; And a reception beam forming unit configured to provide a reception focus delay for focusing the first or second reception signal. delete Stores information on the designated focal point and common focal point different in position and number depending on the object, Transmitting an ultrasonic signal to a common focal point or the designated focal point of the object, receiving a reflected ultrasonic signal from the object to form a received signal, and receiving a reflected signal of the ultrasonic signal transmitted to the common focal point of the object Forming a first received signal, receiving a reflected signal of the ultrasonic signal transmitted to a designated focal point of the object to form a second received signal, Receiving the first received signal to form a base image of the object, and analyzing the base image to determine a designated focal point of the object, And an ultrasound image forming method for receiving the second received signal to form an ultrasound image signal. The method of claim 11, The base image is divided into a plurality of areas based on the location of the common focal point. Detecting a boundary point of the object in each divided area, setting a first reference value based on the number of detected boundary points, Calculate a difference between the average contrast value of the base image and the average contrast value of each segment, set a second reference value based on the calculated difference, And determining whether to specify a focal point of each of the divided regions by using the first reference value and the second reference value. The method of claim 12, And dividing the base image in at least one of a transmission axis direction and a transmission side direction of the ultrasound signal. A computer-readable recording medium having stored thereon a program for performing the ultrasound image forming method according to any one of claims 11 to 13.

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