KR102389866B1 - Method for Generating a Ultrasound Image and Image Processing Apparatus - Google Patents

Abstract

A method and an image processing apparatus for generating an ultrasound image using temporal gain compensation are provided. A method of generating an ultrasound image includes: acquiring ultrasound data; determining effective data for estimating an attenuation degree from among ultrasound data; and estimating an attenuation degree of the ultrasound data based on the effective data; The method may include performing time gain compensation (TGC) on the ultrasound data based on the estimated attenuation degree, and generating an ultrasound image based on the ultrasound data on which time gain compensation has been performed.

Description

Method for Generating a Ultrasound Image and Image Processing Apparatus

The present invention relates to a method of generating an ultrasound image having high quality and an image processing apparatus therefor.

Ultrasound images generated using ultrasound are used in various ways. In particular, ultrasound images have non-invasive and non-destructive properties and are widely used in the medical field. The ultrasound image may be a 2D image or a 3D image of the inside of the object. When an image processing apparatus generating an ultrasound image is an ultrasound diagnosis apparatus, the ultrasound diagnosis apparatus irradiates an ultrasound signal generated from a transducer of a probe to an object, and receives information on an echo signal reflected from the object Thus, an image of a region inside the object can be obtained.

In order to observe the inside of the object using the ultrasound image, it is necessary to generate an ultrasound image clearly showing the inside of the object. However, when acquiring ultrasound data for generating an ultrasound image, an acoustic beam is attenuated while traveling inside the object. For this reason, the intensity of the echo signal returning from the reflector to the transducer becomes weaker as the position of the reflector is further away from the transducer. Accordingly, the image processing apparatus needs to perform time gain compensation in order to compensate for the strength of a signal weakened due to attenuation.

A method and an image processing apparatus for generating an ultrasound image using temporal gain compensation are provided.

As a technical means for achieving the above-described technical problem, a method for generating an ultrasound image according to some embodiments may include: acquiring ultrasound data; determining effective data for estimating an attenuation degree among ultrasound data; Estimating an attenuation degree for ultrasound data based on valid data, performing Time Gain Compensation (TGC) on ultrasound data based on the estimated attenuation degree, and time gain compensation ultrasound The method may include generating an ultrasound image based on the data.

In addition, according to another embodiment, estimating the degree of attenuation includes determining an attenuation coefficient for ultrasound data, and performing time gain compensation includes compensating for a gain for ultrasound data based on the attenuation coefficient. may include steps.

Also, according to another embodiment, the determining of valid data may include determining an effective area for ultrasound data and determining data included in the valid area among ultrasound data as valid data.

In addition, according to another embodiment, the determining of the effective area includes generating a tissue map based on a signal to noise ratio (SNR) for ultrasound data and based on the tissue map. It may include determining an effective area.

Also, according to another embodiment, determining the effective area may include analyzing a spectrum of ultrasound data and determining the effective area based on a standard deviation of the spectrum.

Also, according to another embodiment, the determining of the effective area based on the standard deviation may include determining the effective area based on an increase degree of the standard deviation.

As a technical means for achieving the above-described technical problem, an image processing apparatus for generating an ultrasound image according to some embodiments includes a data acquisition unit acquiring ultrasound data and an image processing unit generating an ultrasound image based on the ultrasound data and the image processing unit determines valid data among the ultrasound data, estimates an attenuation degree of the ultrasound data based on the valid data, and performs time gain compensation (TGC) on the ultrasound data according to the estimated attenuation degree. can be done

Also, according to another embodiment, the image processing unit may determine an attenuation coefficient for the ultrasound data based on the effective data, and perform temporal gain compensation on the ultrasound data based on the attenuation coefficient.

Also, according to another embodiment, the image processing unit may determine an effective area for ultrasound data, and may determine data included in the effective area among ultrasound data as valid data.

Also, according to another embodiment, the image processing unit may generate a tissue map based on a signal-to-noise ratio (SNR) of the ultrasound data, and determine an effective area based on the tissue map. there is.

Also, according to another embodiment, the image processing unit may analyze a spectrum of ultrasound data and determine an effective area based on a standard deviation of the spectrum.

Also, according to another embodiment, the image processing unit may determine the effective area based on the degree of increase of the standard deviation.

As a technical means for achieving the above-described technical problem, a computer-readable recording medium according to some embodiments may be characterized in that a program for executing the above-described method is recorded.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention can be easily understood by the following detailed description and combination of the accompanying drawings, in which reference numerals mean structural elements.
1 is a block diagram illustrating a configuration of an ultrasound diagnosis apparatus according to an exemplary embodiment.
2 is a block diagram illustrating a configuration of a wireless probe according to an embodiment.
3 is a flowchart illustrating a process of generating an ultrasound image according to an exemplary embodiment.
4 is an exemplary diagram illustrating an ultrasound image according to an embodiment.
5 is a block diagram simply illustrating a structure of an image processing apparatus according to some exemplary embodiments.
6 is a flowchart illustrating a process of generating an ultrasound image, according to some embodiments.
7 is a block diagram illustrating a process of performing time gain compensation according to some embodiments.
8 is a block diagram illustrating a process of performing time gain compensation according to some other exemplary embodiments.
9 and 10 are exemplary views illustrating a tissue map generated according to some embodiments.
11 to 13 are conceptual diagrams for explaining spectrum analysis of ultrasound data related to some embodiments.
14 and 15 are exemplary diagrams illustrating a standard deviation of a spectrum, a time gain compensation curve, and a scanline profile according to some embodiments.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those of ordinary skill in the art can easily implement them. However, the present invention may be embodied in several different forms and is not limited to the embodiments described herein. And in order to clearly explain the present invention in the drawings, parts irrelevant to the description are omitted, and similar reference numerals are attached to similar parts throughout the specification.

Throughout the specification, when a part "includes" a certain element, it means that other elements may be further included, rather than excluding other elements, unless otherwise stated. In addition, the “… wealth", "… The term “module” means a unit that processes at least one function or operation, which may be implemented as hardware or software, or a combination of hardware and software.

Throughout the specification, the term “ultrasound image” refers to an image of an object obtained using ultrasound. Also, a subject may include a human or animal, or part of a human or animal. For example, the object may include organs such as the liver, heart, uterus, brain, breast, abdomen, or blood vessels. Also, the object may include a phantom, and the phantom may mean a material having a volume very close to the density and effective atomic number of an organism.

In addition, throughout the specification, a "user" may be a medical professional, such as a doctor, a nurse, a clinical pathologist, a medical imaging specialist, or a technician repairing a medical device, but is not limited thereto.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

According to some embodiments, the image processing apparatus may include the ultrasound diagnosis apparatus 1000 . 1 is a block diagram illustrating a configuration of an ultrasound diagnosis apparatus 1000 according to an embodiment of the present invention. The ultrasound diagnosis apparatus 1000 according to an embodiment includes a probe 20 , an ultrasound transceiver 100 , an image processing unit 200 , a communication unit 300 , a memory 400 , an input device 500 , and a control unit 600 . ), and the various components described above may be connected to each other through the bus 700 . However, the present invention is not limited thereto, and the image processing apparatus may be implemented in the form of a fax viewer, a smart phone, a laptop computer, a PDA, a tablet PC, or a PC.

The probe 20 transmits an ultrasound signal to the object 10 according to a driving signal applied from the ultrasound transceiver 100 , and receives an echo signal reflected from the object 10 . The probe 20 includes a plurality of transducers, and the plurality of transducers vibrate according to a transmitted electrical signal and generate ultrasonic waves, which are acoustic energy. Also, the probe 20 may be connected to the main body of the ultrasound diagnosis apparatus 1000 by wire or wirelessly, and the ultrasound diagnosis apparatus 1000 may include a plurality of probes 20 according to an implementation form.

The transmitter 110 supplies a driving signal to the probe 20 , and includes a pulse generator 112 , a transmission delay unit 114 , and a pulser 116 . The pulse generator 112 generates a pulse for forming a transmission ultrasound according to a predetermined pulse repetition frequency (PRF), and the transmission delay unit 114 determines transmission directionality. A delay time is applied to the pulse. Each pulse to which the delay time is applied corresponds to a plurality of piezoelectric vibrators included in the probe 20 , respectively. The pulser 116 applies a driving signal (or a driving pulse) to the probe 20 at a timing corresponding to each pulse to which a delay time is applied.

The receiver 120 generates ultrasonic data by processing the echo signal received from the probe 20 , and an amplifier 122 , an analog digital converter (ADC) 124 , a reception delay unit 126 , and A summation unit 128 may be included. The amplifier 122 amplifies the echo signal for each channel, and the ADC 124 analog-digitizes the amplified echo signal. The reception delay unit 126 applies a delay time for determining reception directionality to the digitally converted echo signal, and the summing unit 128 sums the echo signals processed by the reception delay unit 166 by Generate ultrasound data. On the other hand, the receiver 120 may not include the amplifier 122 according to its implementation form. That is, when the sensitivity of the probe 20 is improved or the number of processing bits of the ADC 124 is improved, the amplifier 122 may be omitted.

The image processing unit 200 generates and displays an ultrasound image through a scan conversion process on the ultrasound data generated by the ultrasound transceiver 100 . Meanwhile, the ultrasound image is a gray scale image obtained by scanning an object in A mode (amplitude mode), B mode (brightness mode), and M mode (motion mode), as well as a Doppler effect. It may include a Doppler image representing a moving object by using it. The Doppler image includes a blood flow Doppler image (or also referred to as a color Doppler image) indicating blood flow, a tissue Doppler image indicating tissue movement, and a spectral Doppler image indicating a movement speed of an object as a waveform. may include

The B-mode processing unit 212 extracts and processes the B-mode component from the ultrasound data. The image generator 220 may generate an ultrasound image in which signal intensity is expressed as brightness based on the B mode component extracted by the B mode processor 212 .

Similarly, the Doppler processing unit 214 may extract a Doppler component from the ultrasound data, and the image generating unit 220 may generate a Doppler image expressing the motion of the object as a color or a waveform based on the extracted Doppler component.

The image generating unit 220 according to an embodiment may generate a 3D ultrasound image through a volume rendering process for volume data, and may generate an elastic image obtained by imaging the degree of deformation of the object 10 according to pressure. may be Furthermore, the image generator 220 may express various types of additional information as text or graphics on the ultrasound image. Meanwhile, the generated ultrasound image may be stored in the memory 400 .

The display 230 displays and outputs the generated ultrasound image. The display 230 may display and output not only the ultrasound image but also various information processed by the ultrasound diagnosis apparatus 1000 on the screen through a graphic user interface (GUI). Meanwhile, the ultrasound diagnosis apparatus 1000 may include two or more display units 230 according to an implementation form.

The communication unit 300 is connected to the network 30 by wire or wirelessly to communicate with an external device or server. The communication unit 300 may exchange data with a hospital server connected through a picture archiving and communication system (PACS) or other medical devices in the hospital. Also, the communication unit 300 may perform data communication according to a digital imaging and communications in medicine (DICOM) standard.

The communication unit 300 may transmit/receive data related to diagnosis of the object, such as an ultrasound image, ultrasound data, and Doppler data, of the object 10 through the network 30 , and may be photographed by other medical devices such as CT, MRI, and X-ray. A medical image can also be transmitted and received. Furthermore, the communication unit 300 may receive information about a patient's diagnosis history or treatment schedule from the server and use it for diagnosis of the object 10 . Furthermore, the communication unit 300 may perform data communication with a portable terminal of a doctor or a patient as well as a server or medical device in a hospital.

The communication unit 300 may be connected to the network 30 by wire or wirelessly to exchange data with the server 32 , the medical device 34 , or the portable terminal 36 . The communication unit 300 may include one or more components that enable communication with an external device, and may include, for example, a short-range communication module 310 , a wired communication module 320 , and a mobile communication module 330 . can

The short-range communication module 310 means a module for short-distance communication within a predetermined distance. Short-distance communication technology according to an embodiment of the present invention includes wireless LAN, Wi-Fi, Bluetooth, Zigbee, Wi-Fi Direct, UWB (ultra wideband), infrared communication ( IrDA, infrared Data Association), BLE (Bluetooth Low Energy), NFC (Near Field Communication), etc. may be included, but is not limited thereto.

The wired communication module 320 means a module for communication using an electrical signal or an optical signal, and in wired communication technology according to an embodiment, a pair cable, a coaxial cable, an optical fiber cable, an Ethernet cable, etc. may be included.

The mobile communication module 330 transmits/receives wireless signals to and from at least one of a base station, an external terminal, and a server on a mobile communication network. Here, the wireless signal may include various types of data according to transmission and reception of a voice call signal, a video call signal, or a text/multimedia message.

The memory 400 stores various pieces of information processed by the ultrasound diagnosis apparatus 1000 . For example, the memory 400 may store medical data related to diagnosis of an object, such as input/output ultrasound data and ultrasound images, and may store an algorithm or program executed in the ultrasound diagnosis apparatus 1000 .

The memory 400 may be implemented with various types of storage media such as flash memory, hard disk, and EEPROM. Also, the ultrasound diagnosis apparatus 1000 may operate a web storage or a cloud server that performs a storage function of the memory 400 on the web.

The input device 500 refers to a means for receiving data for controlling the ultrasound diagnosis apparatus 1000 from a user. The input device 500 may include, but is not limited to, hardware components such as a keypad, a mouse, a touch panel, a touch screen, a trackball, and a jog switch, and is not limited thereto. , a fingerprint recognition sensor, an iris recognition sensor, a depth sensor, a distance sensor, etc. may further include various input means.

The controller 600 generally controls the operation of the ultrasound diagnosis apparatus 1000 . That is, the control unit 600 controls operations between the probe 20 , the ultrasound transceiver 100 , the image processing unit 200 , the communication unit 300 , the memory 400 , and the input device 500 shown in FIG. 1 . can do.

Some or all of the probe 20 , the ultrasound transceiver 100 , the image processing unit 200 , the communication unit 300 , the memory 400 , the input device 500 , and the control unit 600 may be operated by a software module. However, the present invention is not limited thereto, and some of the above-described configurations may be operated by hardware. In addition, at least some of the ultrasound transceiver 100 , the image processing unit 200 , and the communication unit 300 may be included in the control unit 600 , but the embodiment is not limited thereto.

2 is a block diagram illustrating a configuration of a wireless probe 2000 according to an embodiment. The wireless probe 2000 includes a plurality of transducers as described with reference to FIG. 1 , and may include some or all of the configuration of the ultrasound transceiver 100 of FIG. 1 according to an implementation form.

The wireless probe 2000 according to the embodiment shown in FIG. 2 includes a transmitter 2100 , a transducer 2200 , and a receiver 2300 , and since each configuration has been described in 1, a detailed description is omitted. do. Meanwhile, the wireless probe 2000 may selectively include a reception delay unit 2330 and a summation unit 2340 according to an implementation form thereof.

The wireless probe 2000 may transmit an ultrasound signal to the object 10 , receive an echo signal, generate ultrasound data, and wirelessly transmit the ultrasound data to the ultrasound diagnosis apparatus 1000 of FIG. 1 .

3 is a flowchart illustrating a process of generating an ultrasound image according to an exemplary embodiment. 3 illustrates a process in which the image processing apparatus including the probe 20 generates an ultrasound image, but is not limited thereto.

First, in operation S3100, the image processing apparatus may generate ultrasound data by receiving beamforming an echo signal. Controlling the shape of an ultrasound beam received through an array probe is called reception beamforming. The image processing apparatus may receive ultrasound data generated from another device instead of performing beamforming. The beamformed ultrasound data may be referred to as BF(z).

Here, the ultrasound data may be data generated based on an echo signal attenuated due to the characteristics of the ultrasound signal. Accordingly, in operation S3200, the image processing apparatus may perform gain compensation on the ultrasound data to compensate for the attenuated gain. For example, a value of a gain compensation curve may be multiplied by a value of beamformed ultrasound data according to depth. Here, the gain compensation curve may be an inverse of an attenuation curve of the transmission signal. When the gain compensation curve is Gain(z), the result of performing the gain compensation may be BF(z)*Gain(z). The gain compensation may be time gain compensation (TGC). Here, the degree of attenuation of ultrasonic waves increases as the depth indicating the distance from the probe 20 increases. In addition, ultrasonic waves are attenuated to different degrees depending on the transmission frequency or the type of medium. Also, the degree of reflection of ultrasonic waves varies according to the impedance of the medium. Therefore, it is necessary to perform gain compensation in consideration of the characteristics of various media included in the object.

Thereafter, the image processing apparatus may demodulate the ultrasound data in operation S3300 and detect an envelope from the demodulated data in operation S3400 . Thereafter, the image processing apparatus may generate an ultrasound image based on the number of log compression performed on the ultrasound data in operation S3500 and the log-compressed ultrasound data.

4 is an exemplary diagram illustrating an ultrasound image according to an embodiment. 4A is an ultrasound image 4100 generated based on ultrasound data for which gain compensation is not performed in step S3200 of FIG. 3 . 4B is an ultrasound image 4200 generated based on ultrasound data on which the gain compensation of step S3200 is performed.

Referring to FIG. 4A , in the region 4120 having a deep depth in the ultrasound image 4100 , the image appears dark overall due to the attenuation of the ultrasound. Accordingly, since the contrast of the image in the deep region 4120 is low, it is difficult to distinguish tissues included in the deep region 4120 .

In contrast, referring to FIG. 4B , the contrast in the deep region 4220 in the ultrasound image 4200 is increased by performing gain compensation. Accordingly, the form 4240 of the organization that did not appear before performing the gain compensation is clearly revealed.

5 is a block diagram simply illustrating a structure of an image processing apparatus according to some exemplary embodiments. The components illustrated in FIG. 5 are for describing some embodiments, and the image processing apparatus may include more components than those illustrated in FIG. 5 . In addition, the components shown in FIG. 5 may be substituted with other components performing similar functions. An image processing apparatus according to some embodiments may include a data acquisition unit 5100 and an image processing unit 200 .

The data acquisition unit 5100 may acquire ultrasound data. The data acquisition unit 5100 may be implemented in various ways according to embodiments. For example, the data acquisition unit 5100 may include the probe 20 and the ultrasound transceiver 100 of FIG. 1 . That is, the data acquisition unit 5100 may generate ultrasound data by transmitting an ultrasound signal to the object and receiving an echo signal in which the ultrasound signal is reflected from the object. As another example, the data acquisition unit 5100 may include the communication unit 300 of FIG. 1 . That is, the data acquisition unit 5100 may receive ultrasound data from another device (eg, the server 32 of FIG. 1 , the medical device 34 , or the portable terminal 36 ). As another example, the data acquisition unit 5100 may acquire ultrasound data stored in the memory 400 . However, the present invention is not limited thereto.

The image processing unit 200 may generate an ultrasound image based on ultrasound data. Also, the image processing unit 200 may perform temporal gain compensation on ultrasound data to generate an ultrasound image. That is, the image processing unit 200 may compensate for the degree of attenuation of the ultrasound data.

In order to perform temporal gain compensation, the image processing unit 200 may estimate a degree of attenuation of ultrasound data. The image processing unit 200 may represent the degree of attenuation of the ultrasound data as a gain compensation curve. The image processing unit 200 may perform temporal gain compensation by multiplying the gain compensation curve by the ultrasound data according to the depth.

A medium (eg, liquid) having a low degree of reflection of ultrasound may be included in the object. In this case, ultrasound data corresponding to a region in an ultrasound image of a medium having a low degree of reflection may be invalid data in estimating the degree of attenuation. That is, according to some embodiments, the valid data may refer to data included in an effective area among ultrasound data. In this case, the image processing unit 200 may determine an effective area for ultrasound data, and may determine data included in the effective area among ultrasound data as valid data. Accordingly, the image processing unit 200 needs to estimate the attenuation level based on valid data except for invalid data among ultrasound data. Here, when estimating the degree of attenuation, the image processing unit 200 according to an exemplary embodiment may determine valid data among ultrasound data. The image processing unit 200 may estimate the degree of attenuation of the ultrasound data based on the determined valid data.

The image processing unit 200 according to some embodiments may generate a tissue map and determine an effective area based on the tissue map. Here, the tissue map refers to a chart indicating whether the ultrasound data is valid according to the characteristics of the tissue on the ultrasound data. For example, the image processing unit 200 may determine a region in which a signal to noise ratio (SNR) of ultrasound data is equal to or greater than a threshold value as an effective region, but is not limited thereto. As another example, the image processing unit 200 may analyze a spectrum of ultrasound data and determine an effective region based on a standard deviation of the spectrum.

The image processing unit 200 according to some embodiments may determine an attenuation coefficient to estimate the attenuation degree. The attenuation coefficient may be determined based on Equation 1 below.

Here, β _{dB /cm/MHz} is the attenuation coefficient, c is the average velocity of sound waves, spectral std is the standard deviation of the spectrum for ultrasound data, and df _max (t)/dt is the amount of change of the center frequency according to the depth. The average velocity of the sound wave may be determined as a constant or may be obtained from RF data. The image processing unit 200 may determine the gain compensation curve by multiplying the attenuation coefficient and the center frequency.

6 is a flowchart illustrating a process of generating an ultrasound image, according to some embodiments.

First, in operation S6100, the image processing apparatus may acquire ultrasound data. According to some embodiments, the image processing apparatus may generate ultrasound data by transmitting an ultrasound signal to the object and receiving an echo signal from which the ultrasound signal is reflected from the object. According to another embodiment, the image processing apparatus may receive ultrasound data from another device (eg, the server 32, the medical apparatus 34, or the portable terminal 36 of FIG. 1 ). According to another embodiment, the image processing apparatus may acquire ultrasound data stored in the memory 400 . However, the present invention is not limited thereto.

Thereafter, in operation S6200, the image processing apparatus may determine valid data from among the ultrasound data. Here, the valid data may mean data to be used to estimate the degree of attenuation. Also, according to some embodiments, the valid data may refer to data included in an effective area among ultrasound data. In this case, the image processing apparatus may determine an effective area for ultrasound data in operation S6200 . Thereafter, the image processing apparatus may determine data included in the valid region from among the ultrasound data as valid data.

According to some embodiments, the image processing apparatus may generate a tissue map for ultrasound data. The image processing apparatus may determine, as valid data, ultrasound data corresponding to an area indicated as an effective area in the tissue map. The image processing apparatus may determine a region in which a signal to noise ratio (SNR) of ultrasound data is equal to or greater than a threshold value as an effective region, but is not limited thereto. As another example, the image processing apparatus may analyze a spectrum of ultrasound data and determine an effective region based on a standard deviation of the spectrum.

Thereafter, in operation S6300 , the image processing apparatus may estimate the degree of attenuation of the ultrasound data. Here, the image processing apparatus may estimate the degree of attenuation based on valid data among the ultrasound data. That is, when estimating the degree of attenuation, the image processing apparatus may estimate the degree of attenuation based on data excluding data that is not valid data. According to some embodiments, the image processing apparatus may estimate the degree of attenuation by determining the attenuation coefficient using Equation 1 above.

In operation S6400 , the image processing apparatus may perform temporal gain compensation based on the estimated degree of attenuation. For example, the image processing apparatus may determine a gain compensation curve by multiplying an attenuation coefficient by a center frequency, and perform temporal gain compensation by multiplying the determined gain compensation curve by ultrasound data according to depth. Thereafter, in operation S6500 , the image processing apparatus may generate an ultrasound image based on the attenuation-compensated ultrasound data.

7 is a block diagram illustrating a process of performing time gain compensation according to some embodiments.

The image processing unit 200 according to some embodiments may include a spectrum analyzer 7200 and an effective area determiner 7100 . First, the spectrum analyzer 7200 may Fourier transform ultrasound data ( 7210 ). Here, the ultrasound data may be IQ/RF data. According to some embodiments, the Fourier transform may be a Short-Time Fourier Transform (STFT).

The effective region determiner 7100 may estimate a signal-to-noise ratio based on the converted ultrasound data ( 7110 ). The effective area determiner 7100 may determine the effective area based on the estimated signal-to-noise ratio ( 7120 ). For example, a region in which a signal is greater than noise may be determined as an effective region. Here, the effective area determiner 7100 may generate a tissue map indicating the determined effective area.

According to an embodiment, the spectrum analyzer 7200 may perform averaging and normalizing on ultrasound data included in the effective region ( 7220 ). Thereafter, the spectrum analyzer 7200 may estimate a standard deviation of spectrum (spectral STD) based on the normalized ultrasound data ( 7230 ). Thereafter, the spectrum analyzer 7200 may reduce an error caused by excluding data not included in the effective region by performing smoothing and interpolating on the estimated standard deviation ( 7240 ). The image processing unit 200 may estimate ( 7400 ) the degree of attenuation based on the frequency 7300 estimated based on the ultrasound data and the standard deviation of the spectrum estimated by the spectrum analyzer 7200 . The image processing unit 200 may perform gain compensation 7500 based on the estimated degree of attenuation.

According to another embodiment, the spectrum analyzer may perform averaging and normalizing on the Fourier-transformed (7210) ultrasound data (7220). Thereafter, the spectrum analyzer may estimate a standard deviation of a spectrum with respect to ultrasound data included in the normalized ultrasound data. Thereafter, the spectrum analyzer 7200 may reduce an error caused by excluding data not included in the effective region by performing smoothing and interpolating on the estimated standard deviation ( 7240 ). The image processing unit 200 may estimate ( 7400 ) the degree of attenuation based on the frequency 7300 estimated based on the ultrasound data and the standard deviation of the spectrum estimated by the spectrum analyzer 7200 . The image processing unit 200 may perform gain compensation 7500 based on the estimated degree of attenuation.

8 is a block diagram illustrating a process of performing time gain compensation according to some other exemplary embodiments.

The image processing unit 200 according to some embodiments may include a spectrum analyzer 7200 and an effective area determiner 8100 . First, the spectrum analyzer 7200 may Fourier transform ultrasound data ( 7210 ). Here, the ultrasound data may be IQ/RF data. According to some embodiments, the Fourier transform may be a Short-Time Fourier Transform (STFT).

The effective area determiner 8100 may acquire noise data and ultrasound data related to ultrasound data. The effective area determiner 8100 may estimate a signal-to-noise ratio based on previously acquired noise data and ultrasound data ( S8110 ). The effective area determiner 8100 may determine the effective area based on the estimated signal-to-noise ratio ( 8120 ). Here, the effective area determiner 8100 may generate a tissue map indicating the determined effective area.

According to an embodiment, the spectrum analyzer 7200 may perform averaging and normalizing on ultrasound data included in the effective region ( 7220 ). Thereafter, the spectrum analyzer 7200 may estimate a standard deviation of spectrum (spectral STD) based on the normalized ultrasound data ( 7230 ). Thereafter, the spectrum analyzer 7200 may reduce an error caused by excluding data not included in the effective region by performing smoothing and interpolating on the estimated standard deviation ( 7240 ). The image processing unit 200 may estimate ( 7400 ) the degree of attenuation based on the frequency 7300 estimated based on the ultrasound data and the standard deviation of the spectrum estimated by the spectrum analyzer 7200 . The image processing unit 200 may perform gain compensation 7500 based on the estimated degree of attenuation.

According to another embodiment, the spectrum analyzer may perform averaging and normalizing on the Fourier-transformed (7210) ultrasound data (7220). Thereafter, the spectrum analyzer may estimate a standard deviation of a spectrum with respect to ultrasound data included in the normalized ultrasound data. Thereafter, the spectrum analyzer 7200 may reduce an error caused by excluding data not included in the effective region by performing smoothing and interpolating on the estimated standard deviation ( 7240 ). The image processing unit 200 may estimate ( 7400 ) the degree of attenuation based on the frequency 7300 estimated based on the ultrasound data and the standard deviation of the spectrum estimated by the spectrum analyzer 7200 . The image processing unit 200 may perform gain compensation 7500 based on the estimated degree of attenuation.

9 and 10 are exemplary views illustrating a tissue map generated according to some embodiments.

In particular, FIG. 9 is an exemplary view illustrating an ultrasound image 9100 and a tissue map when the medium of the object is uniform. Referring to FIG. 9A , when the medium of the object is uniform and the object is a reflector that reflects ultrasound, the ultrasound image 9100 shows uniform brightness. FIG. 9B is a tissue map related to the ultrasound image 9100 shown in FIG. 9A . Referring to FIG. 9B , the effective area 9200 occupies most of the tissue map generated based on ultrasound data obtained from an object having a uniform medium.

10 is an exemplary diagram illustrating an ultrasound image and a tissue map of an object including a medium that does not reflect ultrasound. 10A is an ultrasound image of an object including a medium that does not reflect ultrasound. The region 10100 in which the medium that does not reflect the ultrasonic wave is located in the object appears dark as shown in FIG. 10A . That is, the echo signal for the region 10100 in which the non-reflective medium is located has a weaker signal strength than the echo signal for other regions. Referring to FIG. 10B , which is a tissue map generated based on the signal-to-noise ratio, the region 10100 in which the medium is located appears as an invalid region.

11 to 13 are conceptual diagrams for explaining spectrum analysis of ultrasound data related to some embodiments.

11A is an exemplary view illustrating an ultrasound image when the medium is uniform. Also, FIG. 11B is an exemplary diagram illustrating a spectrum related to the ultrasound image shown in FIG. 11A . Referring to FIG. 11B , the width 11010 of the spectrum representing the standard deviation of the spectrum is relatively constant. Referring to FIG. 11(c) , which is a graph of the standard deviation of the spectrum estimated from the ultrasound data of the ultrasound image shown in FIG. 11(a), the standard deviation of the spectrum decreases relatively constantly as the depth increases. .

12A is an exemplary view illustrating an ultrasound image of an object including a medium 12010 that does not reflect ultrasound. FIG. 12(b) is an exemplary view illustrating a spectrum related to the ultrasound image shown in FIG. 12(a). Referring to FIG. 12B , there is a region 12030 in which the width 12020 of the spectrum representing the standard deviation of the spectrum does not constantly decrease, but increases rapidly. Referring to FIG. 12(c), which is a graph of the standard deviation of the spectrum estimated from the ultrasound data of the ultrasound image shown in FIG. 12(a), a section in which the standard deviation of the spectrum rapidly increases as the depth increases 12040) appears. When the standard deviation of the spectrum including the region 12030 is estimated, as shown in FIG. 12C , an error exists in the standard deviation of the estimated spectrum. When estimating the degree of attenuation based on the standard deviation of the spectrum in which there is an error, it is necessary to reduce the error with respect to the standard deviation of the spectrum because an error occurs in the degree of attenuation.

Accordingly, as shown in FIG. 13B , the image display device according to some exemplary embodiments may determine an area in which the standard deviation of the spectrum rapidly increases as the ineffective area 13010 . Also, the image display device may determine an area excluding the non-effective area 13010 as the effective area 13020 . By dividing the spectrum related to the ultrasound image shown in FIG. 13A into an invalid region 13010 and an effective region 13020 , the image processing apparatus generates a tissue map as shown in FIG. 13B . can do. That is, the image processing apparatus according to some embodiments may analyze a spectrum of ultrasound data and determine the effective area 13020 based on the degree of increase according to the depth of the standard deviation of the spectrum. If the standard deviation of the spectrum is estimated based on the spectrum included in the effective region 13020 , as shown in FIG. 13C , it is possible to obtain the standard deviation of the spectrum that decreases as the depth increases.

14 and 15 are exemplary views illustrating a standard deviation of a spectrum, a time gain compensation curve, and a scanline profile according to some embodiments. The scan line profile shown in FIGS. 14 and 15 may be information about any one scan line among a plurality of scan lines.

14 is an exemplary diagram illustrating a standard deviation 14020, a time gain compensation curve 14030, and a scanline profile 14040 of a spectrum when an effective region is not considered. 14A illustrates a case in which ultrasound data acquired through the probe 20 - 1 is for a region 14012 including a uniform medium among the object 14010 . In this case, the standard deviation 14020 of the spectrum estimated from the ultrasound data gradually decreases as the depth increases. In addition, the time gain compensation curve 14030 determined based on the estimated standard deviation gradually increases as the depth increases. As temporal gain compensation is performed on the ultrasound data based on the temporal gain compensation curve 14030 , the intensity of the scanline profile 14040 appears as a constant value.

However, when the position of the probe 20 - 2 is moved as shown in FIG. 14B , the image processing apparatus may acquire ultrasound data for a region including the medium 14014 that does not reflect the ultrasound. In this case, the standard deviation 14020 of the spectrum estimated from the ultrasound data has a rapidly increasing section. The time gain compensation curve 14030 determined based on the standard deviation 14020 of the thus estimated spectrum is determined to be a value (ie, estimated result) smaller than a value required to compensate for the attenuation (ie, theoretical result). As a result, since the time gain compensation is performed based on the time gain compensation curve 14030 determined to be a small value, the intensity of the scanline profile 14040 is weaker than the intensity used to characterize the original medium. .

15 is an exemplary diagram illustrating a standard deviation 15020 of a spectrum, a time gain compensation curve 15030, and a scanline profile 15040 when an effective region is considered, according to some embodiments. FIG. 15A illustrates a case in which ultrasound data acquired through the probe 20 - 1 is for a region 15012 including a uniform medium among the object 15010 . In this case, the standard deviation 15020 of the spectrum estimated from the ultrasound data gradually decreases as the depth increases. In addition, the time gain compensation curve 15030 determined based on the estimated standard deviation gradually increases as the depth increases. As temporal gain compensation is performed on the ultrasound data based on the temporal gain compensation curve 15030 , the intensity of the scanline profile 15040 appears as a constant value.

When the position of the probe 20 - 2 is moved as shown in FIG. 15B , the image processing apparatus may acquire ultrasound data for a region including the medium 15014 that does not reflect the ultrasound. Even in this case, the standard deviation 15020 of the spectrum estimated based on the ultrasound data included in the effective region is constantly reduced. Accordingly, the time gain compensation curve 15030 determined based on the standard deviation 15020 of the spectrum estimated in consideration of the effective area may have a sufficient value. As a result, since the temporal gain compensation is performed based on the temporal gain compensation curve 15030 having a sufficient value, the intensity of the scanline profile 15040 may have sufficient contrast by indicating the original medium.

An embodiment of the present invention may also be implemented in the form of a recording medium including instructions executable by a computer, such as a program module to be executed by a computer. Computer-readable media can be any available media that can be accessed by a computer and includes both volatile and non-volatile media such as ROM, removable and non-removable media such as RAM. In addition, computer-readable media may include both computer storage media and communication media. Computer storage media includes both volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data. Communication media typically includes computer readable instructions, data structures, program modules, or other data in a modulated data signal, or other transport mechanism, and includes any information delivery media. For example, the computer storage medium may be embodied as ROM, RAM, flash memory, CD, DVD, magnetic disk, magnetic tape, or the like.

The above description of the present invention is for illustration, and those of ordinary skill in the art to which the present invention pertains can understand that it can be easily modified into other specific forms without changing the technical spirit or essential features of the present invention. will be. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive. For example, each component described as a single type may be implemented in a dispersed form, and likewise components described as distributed may be implemented in a combined form.

The scope of the present invention is indicated by the following claims rather than the above detailed description, and all changes or modifications derived from the meaning and scope of the claims and their equivalent concepts should be interpreted as being included in the scope of the present invention. do.

Claims (13)

A method for generating an ultrasound image, comprising:
acquiring ultrasound data;
analyzing a spectrum of the ultrasound data;
determining an effective area for the ultrasound data based on a standard deviation of the spectrum;
determining, among the ultrasound data, data included in the effective region as valid data for estimating an attenuation degree;
estimating an attenuation degree of the ultrasound data based on the valid data;
performing time gain compensation (TGC) on the ultrasound data based on the estimated attenuation degree; and
and generating an ultrasound image based on the ultrasound data on which the temporal gain compensation has been performed.
The method of claim 1,
The step of estimating the degree of attenuation includes determining an attenuation coefficient for the ultrasound data,
The performing of the temporal gain compensation includes compensating for a gain of the ultrasound data based on the attenuation coefficient. delete The method of claim 1,
The method of generating the ultrasound image,
generating a tissue map based on a signal to noise ratio (SNR) of the ultrasound data; and
The method of generating an ultrasound image, further comprising determining an effective area based on the tissue map.
delete The method of claim 1,
Determining the effective area based on the standard deviation comprises:
An ultrasound image generating method, characterized in that the effective area is determined based on the degree of increase in the standard deviation. An image processing apparatus for generating an ultrasound image, comprising:
a data acquisition unit configured to acquire ultrasound data; and
an image processing unit generating an ultrasound image based on the ultrasound data;
The image processing unit,
Analyze the spectrum of the ultrasound data, determine an effective area for the ultrasound data based on the standard deviation of the spectrum, and use data included in the effective area among the ultrasound data as effective data for estimating the degree of attenuation and estimating an attenuation degree of the ultrasound data based on the valid data, and performing time gain compensation (TGC) on the ultrasound data according to the estimated attenuation degree.
8. The method of claim 7,
The image processing unit,
determining an attenuation coefficient for the ultrasound data based on the effective data, and performing temporal gain compensation on the ultrasound data based on the attenuation coefficient. delete 8. The method of claim 7,
The image processing unit,
An image processing apparatus for generating a tissue map based on a signal to noise ratio (SNR) of the ultrasound data, and determining an effective area based on the tissue map.
delete 8. The method of claim 7,
The image processing unit,
The image processing apparatus, characterized in that the effective area is determined based on the degree of increase of the standard deviation. A computer-readable recording medium in which a program for executing the method according to claim 1 is recorded.

Images