Ultrasound diagnosis apparatus and method of operating the same

A method of operating an ultrasound diagnosis apparatus includes: acquiring a plurality of frequency band images respectively having different frequency bands based on an ultrasound signal corresponding to an object; determining weights respectively for the plurality of frequency band images based on brightness levels of regions including the object in each of the plurality of frequency band images; synthesizing the plurality of frequency band images based on the weights for the plurality of frequency band images; and displaying a synthetic ultrasound image of the object, generated as a result of the synthesizing.

BACKGROUND

The disclosure relates to an ultrasound diagnosis apparatus and a method of operating the same.

2. Description of Related Art

Ultrasound diagnosis apparatuses transmit, to an object, ultrasound signals generated by transducers of a probe and detect information about signals reflected from the object, thereby obtaining at least one image of an internal part, for example, soft tissue or blood flow, of the object.

SUMMARY

Provided are ultrasound diagnosis apparatuses capable of obtaining a sharp ultrasound image by respectively setting weights corresponding to brightness levels or detail levels for regions of an object in a plurality of frequency band images and synthesizing the plurality of frequency band images or a plurality of steer images according to the set weights.

In accordance with an aspect of the disclosure, a method of operating an ultrasound diagnosis apparatus includes: acquiring a plurality of frequency band images respectively having different frequency bands based on an ultrasound signal corresponding to an object; determining weights respectively for the plurality of frequency band images based on brightness levels of regions including the object in each of the plurality of frequency band images; synthesizing the plurality of frequency band images based on the weights for the plurality of frequency band images; and displaying a synthetic ultrasound image of the object generated as a result of the synthesizing.

In accordance with another aspect of the disclosure, a method of operating an ultrasound diagnosis apparatus includes: acquiring a plurality of steer images based on an ultrasound signal corresponding to an object and acquired according to a beam steering operation by a probe; acquiring a base image representing brightness levels of regions of the object and a detail image representing details of the regions of the object by performing spatial filtering on each of the plurality of steer images; setting weights of base images respectively for the plurality of steer images based on the brightness levels for the regions of the object and synthesizing the base images; setting weights for detail images respectively for the plurality of steer images based on detail levels for the regions of the object and synthesizing the detail images; and displaying a synthetic steer image obtained by combining a synthetic base image acquired by the synthesizing of the base images with a synthetic detail image acquired by the synthesizing of the detail images.

In accordance with another aspect of the disclosure, a computer program is stored on a medium for executing, in an ultrasound diagnosis apparatus, a method of operating the ultrasound diagnosis apparatus.

In accordance with another aspect of the disclosure, an ultrasound diagnosis apparatus includes: a probe configured to transmit an ultrasound signal to an object and receive an ultrasound signal reflected from the object; a processor configured to acquire a plurality of frequency band images respectively having different frequency bands based on the reflected ultrasound signal, determine weights respectively for the plurality of frequency band images based on brightness levels of regions including the object in each of the plurality of frequency band images, and generate a synthetic ultrasound image of the object by synthesizing the plurality of frequency band images based on the weights for the plurality of frequency band images; and a display displaying the synthetic ultrasound image.

DETAILED DESCRIPTION

Certain exemplary embodiments are described in greater detail below with reference to the accompanying drawings. The present specification describes principles of the present disclosure and sets forth embodiments thereof to clarify the scope of the present disclosure and to allow those of ordinary skill in the art to implement the embodiments. The present embodiments may have different forms and should not be construed as being limited to the descriptions set forth herein.

In the following description, the same drawing reference numerals are used for the same elements even in different drawings. The matters defined in the description, such as detailed construction and elements, are provided to assist in a comprehensive understanding of exemplary embodiments. Thus, it is apparent that exemplary embodiments can be carried out without those specifically defined matters. Also, well-known functions or constructions are not described in detail since they would obscure exemplary embodiments with unnecessary detail. Like reference numerals refer to like elements throughout. The present specification does not describe all components in the embodiments, and common knowledge in the art or the same descriptions of the embodiments will be omitted below. Terms such as “part” and “portion” used herein denote those that may be embodied by software or hardware. According to exemplary embodiments, a plurality of parts or portions may be embodied by a single unit or element, or a single part or portion may include a plurality of elements. Expressions such as “at least one of,” when preceding a list of elements, modify the entire list of elements and do not modify the individual elements of the list. Hereinafter, the principles and embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

In exemplary embodiments, an image may include any medical image acquired by various medical imaging apparatuses such as a magnetic resonance imaging (MRI) apparatus, a computed tomography (CT) apparatus, an ultrasound imaging apparatus, or an X-ray apparatus.

Also, in the present specification, an “object”, which is a thing to be imaged, may include a human, an animal, or a part thereof. For example, an object may include a part of a human, that is, an organ or a tissue, or a phantom.

Throughout the specification, an ultrasound image refers to an image of an object processed based on ultrasound signals transmitted to the object and reflected therefrom.

FIG.1is a block diagram illustrating a configuration of an ultrasound diagnosis apparatus100, i.e., a diagnostic apparatus, according to an exemplary embodiment.

Referring toFIG.1, the ultrasound diagnosis apparatus100may include a probe20, an ultrasound transceiver110, a controller120, an image processor130, one or more displays140, a storage150, e.g., a memory, a communicator160, i.e., a communication device or an interface, and an input interface170.

The ultrasound diagnosis apparatus100may be of a cart-type or a portable-type ultrasound diagnosis apparatus that is portable, moveable, mobile, or hand-held. Examples of the portable-type ultrasound diagnosis apparatus may include a smart phone, a laptop computer, a personal digital assistant (PDA), and a tablet personal computer (PC), each of which may include a probe and a software application, but embodiments are not limited thereto.

The probe20may include a plurality of transducers. The plurality of transducers may transmit ultrasound signals to an object10in response to transmitting signals received by the probe20, from a transmitter113. The plurality of transducers may receive ultrasound signals reflected from the object10to generate reception signals. In addition, the probe20and the ultrasound diagnosis apparatus100may be formed in one body (e.g., disposed in a single housing), or the probe20and the ultrasound diagnosis apparatus100may be formed separately (e.g., disposed separately in separate housings) but linked wirelessly or via wires. In addition, the ultrasound diagnosis apparatus100may include one or more probes20according to embodiments.

The controller120may control the transmitter113for the transmitter113to generate transmitting signals to be applied to each of the plurality of transducers based on a position and a focal point of the plurality of transducers included in the probe20.

The controller120may control an ultrasound receiver115to generate ultrasound data by converting reception signals received from the probe20from analog to digital signals and summing the reception signals converted into digital form, based on a position and a focal point of the plurality of transducers.

The image processor130may generate an ultrasound image by using ultrasound data generated from the ultrasound receiver115.

The display140may display a generated ultrasound image and various pieces of information processed by the ultrasound diagnosis apparatus100. The ultrasound diagnosis apparatus100may include two or more displays140according to the present exemplary embodiment. The display140may include a touch screen in combination with a touch panel.

The controller120may control the operations of the ultrasound diagnosis apparatus100and flow of signals between the internal elements of the ultrasound diagnosis apparatus100. The controller120may include a memory for storing a program or data to perform functions of the ultrasound diagnosis apparatus100and a processor and/or a microprocessor (not shown) for processing the program or data. For example, the controller120may control the operation of the ultrasound diagnosis apparatus100by receiving a control signal from the input interface170or an external apparatus.

The ultrasound diagnosis apparatus100may include the communicator160and may be connected to external apparatuses, for example, servers, medical apparatuses, and portable devices such as smart phones, tablet personal computers (PCs), wearable devices, etc., via the communicator160.

The communicator160may include at least one element capable of communicating with the external apparatuses. For example, the communicator160may include at least one among a short-range communication module, a wired communication module, and a wireless communication module.

The communicator160may receive a control signal and data from an external apparatus and transmit the received control signal to the controller120so that the controller120may control the ultrasound diagnosis apparatus100in response to the received control signal.

The controller120may transmit a control signal to the external apparatus via the communicator160so that the external apparatus may be controlled in response to the control signal of the controller120.

For example, the external apparatus connected to the ultrasound diagnosis apparatus100may process the data of the external apparatus in response to the control signal of the controller120received via the communicator160.

A program for controlling the ultrasound diagnosis apparatus100may be installed in the external apparatus. The program may include command languages to perform part of operation of the controller120or the entire operation of the controller120.

The program may be pre-installed in the external apparatus or may be installed by a user of the external apparatus by downloading the program from a server that provides applications. The server that provides applications may include a recording medium where the program is stored.

The storage150may store various data or programs for driving and controlling the ultrasound diagnosis apparatus100, input and/or output ultrasound data, ultrasound images, applications, etc.

The input interface170may receive a user's input to control the ultrasound diagnosis apparatus100and may include a keyboard, button, keypad, mouse, trackball, jog switch, knob, a touchpad, a touch screen, a microphone, a motion input means, a biometrics input means, etc. For example, the user's input may include inputs for manipulating buttons, keypads, mice, trackballs, jog switches, or knobs, inputs for touching a touchpad or a touch screen, a voice input, a motion input, and a bioinformation input, for example, iris recognition or fingerprint recognition, but an exemplary embodiment is not limited thereto.

An example of the ultrasound diagnosis apparatus100according to the present exemplary embodiment is described below with reference toFIGS.2A,2B, and2C.

FIGS.2A,2B, and2Care diagrams illustrating an ultrasound diagnosis apparatus according to an exemplary embodiment.

Referring toFIGS.2A and2B, the ultrasound diagnosis apparatus100aor100bmay include a main display121and a sub-display122. At least one among the main display121and the sub-display122may include a touch screen. The main display121and the sub-display122may display ultrasound images and/or various information processed by the ultrasound diagnosis apparatus100aor100b. The main display121and the sub-display122may provide graphical user interfaces (GUI), thereby receiving user's inputs of data to control the ultrasound diagnosis apparatus100aor100b. For example, the main display121may display an ultrasound image and the sub-display122may display a control panel to control display of the ultrasound image as a GUI. The sub-display122may receive an input of data to control the display of an image through the control panel displayed as a GUI. The ultrasound diagnosis apparatus100aor100bmay control the display of the ultrasound image on the main display121by using the input control data.

Referring toFIG.2B, the ultrasound diagnosis apparatus100bmay include a control panel165. The control panel165may include buttons, trackballs, jog switches, or knobs, and may receive data to control the ultrasound diagnosis apparatus100bfrom the user. For example, the control panel165may include a time gain compensation (TGC) button171and a freeze button172. The TGC button171is to set a TGC value for each depth of an ultrasound image. Also, when an input of the freeze button172is detected during scanning an ultrasound image, the ultrasound diagnosis apparatus100bmay keep displaying a frame image at that time point.

The buttons, trackballs, jog switches, and knobs included in the control panel165may be provided as a GUI to the main display121or the sub-display122.

Referring toFIG.2C, the ultrasound diagnosis apparatus100cmay include a portable device. An example of the portable ultrasound diagnosis apparatus100cmay include smart phones including probes and applications, laptop computers, personal digital assistants (PDAs), or tablet PCs, but an exemplary embodiment is not limited thereto.

The ultrasound diagnosis apparatus100cmay include the probe20and a main body40. The probe20may be connected to one side of the main body40by wire or wirelessly. The main body40may include a touch screen145. The touch screen145may display an ultrasound image, various pieces of information processed by the ultrasound diagnosis apparatus100c, and a GUI.

FIG.3is a diagram for explaining a process of performing image processing on a shadow region in an ultrasound image by using an ultrasound diagnosis apparatus, according to an embodiment.

Referring to an image310ofFIG.3, the ultrasound diagnosis apparatus100may transmit an ultrasound signal to an object and receive an ultrasound signal reflected from the object. The ultrasound diagnosis apparatus100may obtain an ultrasound image of the object based on the reflected ultrasound signal and display the ultrasound image.

When the object has a high medium rigidity, as an ultrasound signal travels deeper into the object, the magnitude of the ultrasound signal rapidly decreases. Furthermore, as the ultrasound signal has more high-frequency components and travels deeper into the object, the magnitude of the ultrasound signal decreases. In other words, as an attenuation coefficient of the ultrasound signal increases, as shown in the image310ofFIG.3, more portions of an ultrasound image may appear dark, or the ultrasound image may have a shadow region311in which a region of the object is invisible.

The shadow region311in the ultrasound image has a lower brightness level than a predetermined brightness level or a higher noise level than a predetermined noise level. Thus, the ultrasound diagnosis apparatus100may clearly display the shadow region311by using image information regarding a low-frequency band image.

The ultrasound diagnosis apparatus100may acquire image information regarding a region corresponding to the shadow region311from the low-frequency band image of the object. The ultrasound diagnosis apparatus100may improve the sharpness of the shadow region311by assigning a high weight to the image information regarding the low-frequency band image and synthesizing the low-frequency band image with a high-frequency band image.

Referring to an image320ofFIG.3, a region in the image320may be sharper than the shadow region311in the image310.

FIG.4is a flowchart of a method of operating the ultrasound diagnosis apparatus100, according to an embodiment.

Referring toFIG.4, the ultrasound diagnosis apparatus100may acquire a plurality of frequency band images respectively having different frequency bands based on an ultrasound signal corresponding to an object (S410).

For example, the ultrasound diagnosis apparatus100may decompose the ultrasound signal according to a plurality of frequency bands. The ultrasound diagnosis apparatus100may acquire, based on the decomposed ultrasound signal, a high-frequency band image corresponding to a predetermined high frequency band and a low-frequency band image corresponding to a predetermined low frequency band.

The ultrasound diagnosis apparatus100may respectively determine weights for the plurality of frequency band images based on brightness values of regions including the object in each of the plurality of frequency band images (S420).

For example, the ultrasound diagnosis apparatus100may detect, in a high-frequency band image, a shadow region having a lower brightness level than a predetermined brightness level and a higher noise level than a predetermined noise level. The ultrasound diagnosis apparatus100may acquire image information regarding a first region corresponding to the shadow region from a low-frequency band image. The ultrasound diagnosis apparatus100may set a weight for image information regarding the first region to be higher than a weight for image information regarding the shadow region in the high-frequency band image.

Furthermore, the ultrasound diagnosis apparatus100may set a weight for image information regarding a non-shadow region in the high-frequency band image to be higher than a weight for image information regarding a second region in the low-frequency band image corresponding to the non-shadow region.

For example, the ultrasound diagnosis apparatus100may acquire a base image representing brightness levels for regions of the object and a detail image representing details of the regions of the object by performing spatial filtering on each of the plurality of frequency band images. The ultrasound diagnosis apparatus100may set, based on brightness levels for the regions of the object, a weight for a base image in each of a plurality of frequency bands. Furthermore, the ultrasound diagnosis apparatus100may set, based on detail levels of the regions of the object, a weight for a detail image in each of the plurality of frequency bands. A process, performed by the ultrasound diagnosis apparatus100, of respectively setting weights for a base image and a detail image and obtaining a synthetic ultrasound image based on the weights will be described in more detail below with reference toFIGS.6through9.

For example, the ultrasound diagnosis apparatus100may receive, via a UI device, an input of adjusting a strength of a weight for image information regarding a low-frequency band image among a plurality of frequency band images. The ultrasound diagnosis apparatus100may adjust, based on the input for adjusting a strength of a weight, a weight for image information regarding a low-frequency band image.

The ultrasound diagnosis apparatus100may synthesize the plurality of frequency band images based on the weights therefor (S430).

For example, the ultrasound diagnosis apparatus100may synthesize base images in the plurality of frequency bands according to weights respectively assigned to the base images. For example, a weight may be set within a range of 0 to 1. The weights of the base images may be added together to equal 1. Furthermore, a weight may be set for each region in a base image. Furthermore, a weight may be set within a range of 0% to 100%. The ultrasound diagnosis apparatus100may respectively multiply weights assigned to the base images by brightness values of the base images to acquire brightness values to which the weights have been applied. The ultrasound diagnosis apparatus100may acquire a synthetic base image by adding together the brightness values of to which the corresponding weights have been applied. Furthermore, the ultrasound diagnosis apparatus100may acquire a synthetic base image by outputting maximum absolute brightness values. For example, the ultrasound diagnosis apparatus100may determine a brightness value having a maximum absolute value among brightness values for each region of a base image and acquire a synthetic base image by synthesizing regions with maximum absolute brightness values.

Furthermore, the ultrasound diagnosis apparatus100may synthesize detail images in a plurality of frequency bands according to weights respectively assigned to the detail images. Detail images may be synthesized in the same manner that the base images are synthesized.

The ultrasound diagnosis apparatus100may obtain a synthetic ultrasound image by combining a synthetic base image with a synthetic detail image.

For example, the ultrasound diagnosis apparatus100may synthesize high- and low-frequency band images based on a weight for image information regarding the low-frequency band image, which is adjusted according to a user input.

The ultrasound diagnosis apparatus100may display a synthetic ultrasound image of the object generated as a result of the synthesis (S440).

The ultrasound diagnosis apparatus100may display the synthetic ultrasound image and an original ultrasound image obtained based on the ultrasound signal. The ultrasound diagnosis apparatus100may display a result of comparing a sharpness or noise between the synthetic and original ultrasound images.

The ultrasound diagnosis apparatus100may respectively set weights corresponding to brightness levels or detail levels for regions of the object in a plurality of frequency band images and synthesize the plurality of frequency band images, thereby obtaining a sharp ultrasound image. Thus, the ultrasound diagnosis apparatus100may clearly display dark and bright regions in an ultrasound image. Furthermore, the ultrasound diagnosis apparatus100may increase uniformity of an ultrasound image by compensating brightness for regions of the object.

FIG.5is a diagram for explaining a process, performed by the ultrasound diagnosis apparatus100, of performing image processing by using high- and low-frequency band images, according to an embodiment.

The ultrasound diagnosis apparatus100may transmit an ultrasound signal to an object and receive an ultrasound signal reflected from the object. The ultrasound diagnosis apparatus100may obtain an ultrasound image510base on the reflected ultrasound signal and display the ultrasound image510.

Because a shadow region exists in the ultrasound image510, the user may input a command that instructs the ultrasound diagnosis apparatus100to perform a task of correcting an image of the shadow region. The ultrasound diagnosis apparatus100may perform the task of correcting an image of the shadow region according to the user's command. Furthermore, the ultrasound diagnosis apparatus100may determine whether the shadow region exists in the ultrasound image510displayed via the ultrasound diagnosis apparatus100When the shadow region exists therein, the ultrasound diagnosis apparatus100may perform the task of correcting an image of the shadow region.

For example, the ultrasound diagnosis apparatus100may acquire high- and low-frequency band images520and530for the ultrasound image510. In detail, the ultrasound diagnosis apparatus100may acquire high-frequency band image data by passing an ultrasound signal through a high-pass filter that allows only a signal in a predetermined high frequency band to pass. The ultrasound diagnosis apparatus100may then acquire the high-frequency band image520based on the high-frequency band image data. Furthermore, the ultrasound diagnosis apparatus100may acquire low-frequency band image data by passing the ultrasound signal through a low-pass filter that allows only a signal in a predetermined low frequency band to pass. The ultrasound diagnosis apparatus100may then acquire the low-frequency band image530based on the low-frequency band image data.

The high-frequency band image520may have a higher resolution than that of the low-frequency band image530. Thus, details of the object represented in the low-frequency band image530may be compensated by details of the object represented in the high-frequency band image520.

Furthermore, because an ultrasound signal in a low frequency band suffers less attenuation than an ultrasound signal in a high frequency band, the ultrasound signal in the low frequency band may travel deeper into the object than the ultrasound signal in the high frequency band. Thus, the low-frequency band image530may show a deep region of the object compared to the high-frequency band image520. Thus, a deep region of the object that is not clearly represented in the high-frequency band image520may be complemented by using image information regarding the low-frequency band image530.

The ultrasound diagnosis apparatus100may detect a shadow region521in the high-frequency band image520. The ultrasound diagnosis apparatus100may acquire image information regarding a region531corresponding to the shadow region521from the low-frequency band image530. The ultrasound diagnosis apparatus100may compensate a brightness or details of the shadow region521in the high-frequency band image520by using image information regarding the region531in the low-frequency band image530.

In detail, the ultrasound diagnosis apparatus100may set a weight for image information regarding the region531in the low-frequency band image530to be higher than a weight for image information regarding the shadow region521in the high-frequency band image520and synthesize the high- and low-frequency band images520and530according to the weights. As a result of the synthesis, the ultrasound diagnosis apparatus100may obtain a synthetic ultrasound image540.

Referring to the synthetic ultrasound image540ofFIG.5, the object in the synthetic ultrasound image540may be shown more clearly than that in the ultrasound image510. Furthermore, a portion of the object depicted in the region541of the synthetic ultrasound image540may appear clearer than the corresponding portion of the object in the shadow region521of the high-frequency band image520. Furthermore, there is reduced noise in the region541of the synthetic ultrasound image540, compared to in the region531of the low-frequency band image530. In other words, the ultrasound diagnosis apparatus100may prevent an increase in noise in the region541of the synthetic ultrasound image540by using the low-frequency band image530,

Furthermore, by using the low-frequency band image530with a low attenuation coefficient, the ultrasound diagnosis apparatus100may distinguish a dark region having a high attenuation from a dark region having a low reflection coefficient and prevent an excessive change in brightness of a region with a low reflection coefficient.

FIG.6is a flowchart of a method of operating the ultrasound diagnosis apparatus100, according to an embodiment.

Referring toFIG.6, the ultrasound diagnosis apparatus100may acquire a base image representing brightness levels for regions of the object and a detail image representing details of the regions of the object by performing spatial filtering on each of the plurality of frequency band images (S610).

The ultrasound diagnosis apparatus100may respectively set weights for base images for the plurality of frequency band images based on the brightness levels for the regions of the object, and synthesize the base images according to the weights (S620).

For example, with respect to a bright region having a brightness level that is greater than or equal to a first level among brightness levels lower than a first reference level used as a reference in representing the brightness levels for the regions of the object, the ultrasound diagnosis apparatus100may set a weight for image information regarding a base image for a high-frequency band image to be higher than a weight for image information regarding a base image for a low-frequency band image.

Furthermore, with respect to a dark region having a brightness level that is less than the first level among the brightness levels lower than the first reference level, the ultrasound diagnosis apparatus100may set a weight for image information regarding a base image for a low-frequency band image to be higher than a weight for image information regarding a base image for a high-frequency band image.

The ultrasound diagnosis apparatus100may respectively set weights for detail images for the plurality of frequency band images based on detail levels for the regions of the object, and synthesize the detail images according to the weights (S630).

For example, with respect to a bright region having a detail level that is greater than or equal to a second level among detail levels lower than a second reference level used as a reference in representing sharpness levels for the regions of the object, the ultrasound diagnosis apparatus100may set a weight for image information regarding a detail image for a high-frequency band image to be higher than a weight for image information regarding a detail image for a low-frequency band image.

Furthermore, with respect to a dark region having a detail level that is less than the second level among the detail levels lower than the second reference level, the ultrasound diagnosis apparatus100may set a weight for image information regarding a detail image for a low-frequency band image to be higher than a weight for image information regarding a detail image for a high-frequency band image.

The ultrasound diagnosis apparatus100may obtain a synthetic ultrasound image by combining a synthetic base image with a synthetic detail image (S640). The ultrasound diagnosis apparatus100may display the synthetic ultrasound image.

FIG.7is a diagram for explaining a brightness range that is expanded by using high- and low-frequency band images when generating an ultrasound image, according to an embodiment.

Referring to an image710ofFIG.7, a brightness range for an ultrasound image generated by the ultrasound diagnosis apparatus100may be a first range701. Only a bright region having a brightness greater than or equal to a reference level711may be represented in the ultrasound image while a region having a brightness less than the reference level711may not be represented therein.

In addition, brightness ranges for high- and low-frequency band images may be second and third ranges702and703, respectively. The ultrasound diagnosis apparatus100may acquire image information regarding the region having brightness less than the reference level711from the high-and low-frequency band images.

For example, the ultrasound diagnosis apparatus100may acquire, from the high-frequency band image, image information regarding a region having a brightness range704that is greater than or equal to a first level712but less than the reference level711. Furthermore, the ultrasound diagnosis apparatus100may acquire, from the low-frequency band image, image information regarding a region having a brightness range705that is greater than or equal to a second level713but less than the first level712.

The high-frequency band image has a higher resolution than that of the low-frequency band image. Thus, when generating a region having a brightness that falls within the brightness range704, the ultrasound diagnosis apparatus100may set a weight for image information regarding the high-frequency band image to be higher than a weight for image information regarding the low-frequency band image and synthetize the high- and low-frequency band images according to the set weights.

Furthermore, the low-frequency band image contains image information to the extent of a deep region of an object compared to the high-frequency band image. Thus, when generating a region having a brightness that falls within the brightness range705, the ultrasound diagnosis apparatus100may set a weight for image information regarding the low-frequency band image to be higher than a weight for image information regarding the high-frequency band image and synthetize the high- and low-frequency band images according to the set weights.

Referring to a graph720ofFIG.7, when the ultrasound diagnosis apparatus100displays an ultrasound image generated based on an ultrasound signal without performing a process for correcting a shadow region in the ultrasound image, a brightness range available for the ultrasound image may be a range that is greater than or equal to the reference level711. The intensity in the graph720represents the brightness.

Otherwise, when the ultrasound diagnosis apparatus100performs a process for correcting a shadow region in an ultrasound image, the ultrasound diagnosis apparatus100may generate an ultrasound image having the brightness range705that is greater than or equal to the second level713but less than the first level712from an image having the brightness range704that is greater than or equal to the first level712but less than the reference level711. Thus, a brightness range available for the ultrasound image may be expanded beyond the range greater than or equal to the reference level711into the brightness range721.

In other words, the ultrasound diagnosis apparatus100may expand a brightness range available for the ultrasound image by using the high- and low-frequency band images.

FIG.8is a diagram for explaining a process, performed by the ultrasound diagnosis apparatus100, of respectively determining weights for a plurality of frequency band images and synthesizing the plurality of frequency band images according to the weights, according to an embodiment.

Referring to an image810ofFIG.8, the ultrasound diagnosis apparatus100may acquire the number N of frequency band images having different frequency bands based on an ultrasound signal corresponding to an object. In detail, the ultrasound diagnosis apparatus100may acquire a first frequency band image811, a second frequency band image812having a second frequency band, . . . , and an N-th frequency band image813having an N-th frequency band.

The ultrasound diagnosis apparatus100may acquire brightness values of a plurality of regions into which each of the N frequency band images is segmented. Referring toFIG.8, ikmlrepresents a brightness value at m-th row and l-th column in a k-th frequency band image. As shown inFIG.8, the ultrasound diagnosis apparatus100may display each of the N frequency band images as a brightness map representing brightness values of a plurality of regions.

Referring to an image820ofFIG.8, the ultrasound diagnosis apparatus100may acquire brightness values of a plurality of regions in a synthetic ultrasound image825. For example, the ultrasound diagnosis apparatus100may respectively determine weights for the N frequency band images based on brightness values of a plurality of regions in each of the N frequency band images and acquire brightness values of the plurality of regions in the synthetic ultrasound image825by respectively applying the weights to the N frequency band images.

A weight for a specific region in a specific frequency band image may be determined based on at least one of a noise level and a brightness level of the region. For example, as described with reference toFIG.7, the ultrasound diagnosis apparatus100may acquire first image information regarding a region in the high-frequency band image, having a brightness level within the brightness range704that is greater than or equal to the first level712but less than the reference level711. The ultrasound diagnosis apparatus100may set a weight for the first image information to be higher than a weight for image information regarding the low-frequency band image.

Referring toFIG.8, Imlrepresents a brightness value at m-th row and l-th column in the synthetic ultrasound image825. wkmidenotes a weight for a brightness value at the m-th row and l-th column in a k-th frequency band image. For example, I11may be calculated by using Equation (1). I12may be calculated by using Equation (2). I44may be calculated by using Equation (3). Brightness values for the other regions in the synthetic ultrasound image825may also be calculated in the same manner as above.

FIG.9is a diagram for explaining a process, performed by the ultrasound diagnosis apparatus100, of acquiring a base image and a detail image for each of a plurality of frequency band images and synthesizing the plurality of frequency band images by using acquired base images and detail images, according to an embodiment.

The ultrasound diagnosis apparatus100may acquire, based on an ultrasound signal reflected from an object, high-frequency band images corresponding to high frequency bands and low-frequency band images corresponding to low frequency bands. For convenience,FIG.9shows only one of the high-frequency images and one of the low-frequency band images. The ultrasound diagnosis apparatus100may acquire a high-frequency band image910and a low-frequency band image920based on an ultrasound signal reflected from an object.

As shown inFIG.9, a shadow region901in the high-frequency band image910does not accurately represent image information of the object. On the other hand, a region902in the low-frequency band image920may correspond to the shadow region901and represent image information of the object. Furthermore, the high-frequency band image910may clearly depict the object. On the other hand, the low-frequency band image920may not clearly depict an edge region of the object and include noise.

Thus, the ultrasound diagnosis apparatus100may acquire image information regarding a region that clearly depicts the object in the high-frequency band image910and image information regarding a region of the object that is not visible in the high-frequency band image910.

In detail, the ultrasound diagnosis apparatus100may acquire a base image911in a high frequency band and a base image921in a low frequency band that represent brightness values for regions of the object by respectively performing spatial filtering on the high-and low-frequency band images910and920. For example, the ultrasound diagnosis apparatus100may acquire the base images911and921in high-and low-frequency bands by respectively passing the high-and low-frequency band images910and920through an edge preserving filter.

Furthermore, the ultrasound diagnosis apparatus100may acquire a detail image912in the high frequency band, which represents details of regions of the object by removing the base image911in the high frequency band from the high-frequency band image910. Similarly, the ultrasound diagnosis apparatus100may acquire a detail image922in the low frequency band by removing the base image921in the low frequency band from the low-frequency band image920.

For a bright region in the base image911having a brightness level that is greater than or equal to a first level among brightness levels lower than a first reference level used as a reference in representing the brightness levels for the regions of the object, the ultrasound diagnosis apparatus100may set a weight for image information regarding the base image911in the high frequency band to be higher than a weight for image information regarding the base image921in the low frequency band. In this case, the first level may be a threshold level for brightness in the high frequency band, which allows for a predetermined level of noise. Thus, a region having a brightness level less than the first level may have a low sharpness level due to noise.

Furthermore, for a dark region in the base image911in the frequency band, which has a brightness level that is less than the first level among the brightness levels lower than the first reference level, the ultrasound diagnosis apparatus100may set a weight for image information regarding the base image921in the low-frequency band to be higher than a weight for image information regarding the base image911in the high frequency band. For example, the dark region in the base image911in the high frequency band, which has a brightness level less than the first level, may correspond to a region903. The ultrasound diagnosis apparatus100may set a weight for image information regarding a region905in the base image921in the low frequency band to be higher than a weight for image information regarding the region903in the base image911in the high frequency band. In addition, because brightness in the low frequency band also has its threshold brightness level that allows for a predetermined level of noise, the ultrasound diagnosis apparatus100may acquire image information regarding a region having a brightness level that is greater than or equal to the threshold brightness level but less than the first level.

The ultrasound diagnosis apparatus100may generate a synthetic base image930by synthesizing the base image911in the high frequency band with the base image921in the low frequency band based on weights respectively set for regions in the base images911and921.

For a bright region in the detail image912in the high frequency band, which has a detail level that is greater than or equal to a second level among detail levels lower than a second reference level used as a reference in representing sharpness levels for the regions of the object, the ultrasound diagnosis apparatus100may set a weight for image information regarding the detail image912in the high frequency band to be higher than a weight for image information regarding the detail image922in the low frequency band. In this case, the second level may be a threshold level for details in the high frequency band, which allows for a predetermined level of noise. Thus, a bright region having a detail level less than the second level may have a low sharpness level due to noise.

Furthermore, for a dark region in the detail image912in the high frequency band, which has a detail level that is less than the second level among the detail levels lower than the second reference level, the ultrasound diagnosis apparatus100may set a weight for image information regarding the detail image922in the low frequency band to be higher than a weight for image information regarding the detail image912in the high frequency band. For example, the dark region in the detail image912in the high frequency band, which has a detail level less than the second level, may correspond to a region904. The ultrasound diagnosis apparatus100may set a weight for image information regarding a region906in the detail image922in the low frequency band to be higher than a weight for image information regarding the region904in the detail image912in the high frequency band. In addition, because details in the low frequency band also has its threshold detail level that allows for a predetermined level of noise, the ultrasound diagnosis apparatus100may acquire image information regarding a region having a detail level that is greater than or equal to the threshold detail level but less than the second level.

The ultrasound diagnosis apparatus100may generate a synthetic detail image940by synthesizing the detail image912in the high frequency band with the detail image922in the low frequency band based on weights respectively set for regions in the detail images912and922.

The ultrasound diagnosis apparatus1000may generate a synthetic ultrasound image950by combining the synthetic base image930with the synthetic detail image940. For example, a region951in the synthetic ultrasound image950may be generated by synthesizing a region931in the synthetic base image930with a region941in the synthetic detail image940.

The ultrasound diagnosis apparatus100may generate the synthetic ultrasound image950to sharpen details that are not seen in bright or dark regions of an original ultrasound image.

FIG.10is a diagram for explaining a process, performed by the ultrasound diagnosis apparatus100, of receiving an input for adjusting a strength of a weight for specific image information and synthesizing a plurality of frequency band images according to the weight with the adjusted strength, according to an embodiment.

Referring to an image1010ofFIG.10, an ultrasound image displayed by the ultrasound diagnosis apparatus100may include a shadow region1011where a portion of an object is not clearly seen. The ultrasound diagnosis apparatus100may automatically detect the shadow region1011via analysis of the ultrasound image. Furthermore, the ultrasound diagnosis apparatus100may acquire the shadow region1011based on a user input.

The ultrasound diagnosis apparatus100may receive a command for performing a process of improving image quality for the shadow region1011and perform its operations described with reference toFIGS.4through9according to the command.

Referring to an image1020ofFIG.10, the ultrasound diagnosis apparatus100may receive an input of changing a “Shadow High Dynamic Range (HDR)” function to an on state via the UI device. In this case, the “Shadow HDR” function may be a function for sharpening the shadow region1011in the ultrasound image. Furthermore, although the function for sharpening the shadow region1011in the ultrasound image is indicated as the term “Shadow HDR” inFIG.10, the function may be indicated as other terms.

According to the input for changing the “Shadow HDR” function to the on state, the ultrasound diagnosis apparatus100may perform an operation of correcting the shadow region1011in the ultrasound image. While performing the operation of correcting the shadow region1011, the ultrasound diagnosis apparatus100may perform correction to improve not only a sharpness level of the shadow region1011but also the overall sharpness of the ultrasound image.

In addition, the ultrasound diagnosis apparatus100may receive, via a UI interface, an input for adjusting a strength of a weight to be applied to a low-frequency band image for synthesis of high- and low-frequency band images. For example, a strength of a weight may be adjustable from 0 to 10. When the strength of a weight is 0, a weight to be applied to a low-frequency band image is 0. When the strength of a weight is 10, a weight to be applied to a low-frequency band image is a maximum value of 10.

As shown in the image1020ofFIG.10, the ultrasound diagnosis apparatus100may receive, via the UI device, an input for adjusting a strength of a weight to be applied to a low-frequency band image to 5. The ultrasound diagnosis apparatus100may synthesize the high-and low-frequency band images according to the weight with the adjusted strength.

Furthermore, the ultrasound diagnosis apparatus100may receive, via the UI device, an input for setting a plurality of regions of interest (ROIs) in an ultrasound image as well as an input for respectively adjusting strengths of a weight to be applied to a low-frequency band image for the plurality of ROIs. The ultrasound diagnosis apparatus100may synthesize the high- and low-frequency band images based on weights with strengths respectively adjusted for the ROIs.

FIG.11is a diagram for explaining a synthetic ultrasound image obtained by the ultrasound diagnosis apparatus100according to strengths of weights, according to an embodiment.

An image1110ofFIG.11is an ultrasound image obtained by the ultrasound diagnosis apparatus100when a “Shadow HDR” function is in an off state. As shown in the image1110ofFIG.11, the ultrasound image may include a dark region1112and a region1111where a region of an object is not well seen.

For example, the user may examine the ultrasound image displayed by the ultrasound diagnosis apparatus100and perform the “Shadow HDR” function. As shown in the image1020ofFIG.10, the user may adjust a strength of a weight to be applied to a low-frequency band image.

For example, an image1120ofFIG.11may be a synthetic ultrasound image when a strength of a weight applied to the low-frequency band image is 5. On the other hand, an image1130ofFIG.11may be a synthetic ultrasound image when a strength of a weight applied to the low-frequency band image is 10.

Detail levels for regions1121and1122in the image1120ofFIG.11are respectively increased compared to detail levels for the regions1111and1112in the image1110ofFIG.11. Furthermore, a noise level for the region1121in the image1120is reduced compared to the region1111in the image1110.

A detail level for a region1132in the image1130is increased compared to the detail level for the region1112in the image1110. However, a detail level for a region1131in the image1130may be reduced compared to the detail level for the region1111due to an increase in noise. Furthermore, the detail levels for the regions1131in the image1130is reduced compared to the detail levels for the regions1121in the image1120.

By comparing the image1120with the image1130, it can be seen that the synthetic ultrasound image may have an improved quality when the strength of the weight to be applied to the low-frequency band image is adjusted to 5, compared to when the strength of the weight is adjusted to 10. Thus, when a “Shadow HDR” function is performed by the ultrasound diagnosis apparatus100, a strength of a weight to be applied to a low-frequency band image needs to be adjusted properly.

The ultrasound diagnosis apparatus100may adjust a strength of a weight to be applied to a low-frequency band image to improve the quality of an ultrasound image by using attenuation characteristics of the low-frequency band image.

FIG.12is a flowchart of a method of operating the ultrasound diagnosis apparatus100, according to an embodiment

Referring toFIG.12, the ultrasound diagnosis apparatus100may acquire a plurality of steer images based on an ultrasound signal corresponding to an object and acquired according to a beam steering operation by a probe (S1210).

The ultrasound diagnosis apparatus100may acquire a base image representing brightness levels of regions of the object and a detail image representing details of the regions of the object by performing spatial filtering on each of the plurality of steer images (S1220).

The ultrasound diagnosis apparatus100may respectively set weights of base images for the plurality of steer images, based on the brightness levels for the regions of the object (S1230). The ultrasound diagnosis apparatus100may also synthesize the base images for the plurality of steer images according to the weights respectively set for the base images. For example, the ultrasound diagnosis apparatus100may acquire a synthetic base image by respectively multiplying weights assigned to the base images by brightness values of the base images and adding the resulting products together. As another example, the ultrasound diagnosis apparatus100may select a base image having a maximum brightness value from among the base images for each region of the base image and acquire a synthetic base image by synthesizing selected base images.

The ultrasound diagnosis apparatus100may respectively set weights for detail images for the plurality of steer images, based on detail levels for the regions of the object (S1240). The ultrasound diagnosis apparatus100may also synthesize the detail images for the plurality of steer images according to the weights respectively set for the detail images. A method of synthesizing the detail images for the plurality of steer images may be substantially the same as the method of synthesizing the base images for the plurality of steer images in operation S1230.

The ultrasound diagnosis apparatus100may obtain a synthetic steer image by combining a synthetic base image with a synthetic detail image (S1250). The ultrasound diagnosis apparatus100may display the synthetic ultrasound image.

FIG.13is a block diagram of a configuration of an ultrasound diagnosis apparatus100according to an embodiment.

Referring toFIG.13, the ultrasound diagnosis apparatus100may include a probe1310, a UI device1320, a display1330, a memory1340, and a processor1350. However, all the components shown inFIG.13are not essential components. The ultrasound diagnosis apparatus100may include more or fewer components than those shown inFIG.13. Structures and operations of the components are now described in more detail. The ultrasound diagnosis apparatus100ofFIG.13may correspond to the ultrasound diagnosis apparatus100,100a,100b, or100cdescribed with reference toFIG.1or2. Furthermore, the ultrasound diagnosis apparatus100ofFIG.13may perform the operation methods described with reference toFIGS.3through8.

The probe1310may include a plurality of transducers that convert ultrasound signals into electrical signals or vice versa. In other words, the probe1310may include a transducer array consisting of a plurality of transducers, and the plurality of transducers may be arranged in a one-dimensional (1D) or 2D array. Each of the plurality of transducers generates ultrasound signals separately or simultaneously. An ultrasound signal transmitted by each transducer is reflected off a discontinuous impedance surface within an object. Each transducer may convert a reflected echo signal into an electrical reception signal.

The UI device1320refers to a device via which data or signals for controlling the ultrasound diagnosis apparatus100are input by the user. The processor1350may control the display1330to generate and output a UI screen for receiving a predetermined command or data from the user.

The display1330displays a predetermined screen. In detail, the display1330may display a predetermined screen according to control by the processor1350. The display1330includes a display panel (not shown) on which an image such as an ultrasound image may be displayed.

The memory1340may store a program for executing a method of operating the ultrasound diagnosis apparatus100. Furthermore, the memory may store a code representing a method of operating the ultrasound diagnosis apparatus100.

The processor1350may acquire a plurality of frequency band images respectively having different frequency bands based on an ultrasound signal corresponding to the object and acquired via the probe1310.

For example, the processor1350may decompose the ultrasound signal according to a plurality of frequency bands. The processor1350may acquire, based on the decomposed ultrasound signal, a high-frequency band image corresponding to a predetermined high frequency band and a low-frequency band image corresponding to a predetermined low frequency band.

The processor1350may respectively determine weights for the plurality of frequency band images based on brightness values of regions including the object in each of the plurality of frequency band images.

For example, the processor1350may detect, in a high-frequency band image, a shadow region having a lower brightness level than a predetermined brightness level and a higher noise level than a predetermined noise level. The processor1350may acquire image information regarding a first region corresponding to the shadow region from a low-frequency band image. The processor may set a weight for the image information regarding the first region to be higher than a weight for image information regarding the shadow region in the high-frequency band image.

Furthermore, the processor1350may set a weight for image information regarding a non-shadow region in the high-frequency band image to be higher than a weight for image information regarding a second region in the low-frequency band image, corresponding to the non-shadow region.

For example, the processor1350may acquire a base image representing brightness levels for regions of the object and a detail image representing details of the regions of the object by performing spatial filtering on each of the plurality of frequency band images. The processor1350may set, based on brightness levels for the regions of the object, a weight for a base image in each of a plurality of frequency bands. Furthermore, the processor1350may set, based on detail levels of the regions of the object, a weight for a detail image in each of the plurality of frequency bands.

For example, the processor1350may receive, via the UI device1320, an input for adjusting a strength of a weight for image information regarding a low-frequency band image among the plurality of frequency band images. The processor1350may adjust, based on the input for adjusting a strength of a weight, a weight for image information regarding a low-frequency band image.

The processor1350may synthesize the plurality of frequency band images based on the weights therefor.

For example, the processor1350may synthesize base images in the plurality of frequency bands according to weights respectively assigned to the base images. The processor1350may synthesize detail images in a plurality of frequency bands according to weights respectively assigned to the detail images. The processor1350may obtain a synthetic ultrasound image by combining a synthetic base image with a synthetic detail image.

As a specific example, for a bright region having a brightness level that is greater than or equal to a first level among brightness levels lower than a first reference level used as a reference in representing the brightness levels for the regions of the object, the processor1350may set a weight for image information regarding a base image for a high-frequency band image to be higher than a weight for image information regarding a base image for a low-frequency band image.

Furthermore, for a dark region having a brightness level that is less than the first level among brightness levels lower than the first reference level, the processor1350may set a weight for image information regarding a base image for a low-frequency band image to be higher than a weight for image information regarding a base image for a high-frequency band image.

The processor1350may generate a synthetic base image by synthesizing the base image for the high-frequency band image with the base image for the low-frequency band image, based on weights respectively set for regions in the base images.

For a bright region having a detail level that is greater than or equal to a second level among detail levels lower than a second reference level used as a reference in representing sharpness levels for the regions of the object, the processor1350may set a weight for image information regarding a detail image for the high-frequency band image to be higher than a weight for image information regarding a detail image for the low-frequency band image.

Furthermore, for a dark region having a detail level that is less than the second level among detail levels lower than the second reference level, the processor1350may set a weight for image information regarding the detail image for the low-frequency band image to be higher than a weight for image information regarding the detail image for the high-frequency band image.

The processor1350may generate a synthetic detail image by synthesizing the detail image for the high-frequency band image with the detail image for the low-frequency band image, based on weights respectively set for regions in the detail images. Then, the processor1350may generate a synthetic ultrasound image by combining the synthetic base image with the synthetic detail image.

As another example, the processor1350may synthesize the high- and low-frequency band images based on a weight for image information regarding the low-frequency band image, which is adjusted according to a user input.

The display1330may display a synthetic ultrasound image of the object generated as a result of the synthesis.

The display1330may display the synthetic ultrasound image and an original ultrasound image obtained based on the ultrasound signal. The display1330may display a result of comparing a sharpness or noise between the synthetic and original ultrasound images.

In addition, the processor1350may acquire a plurality of steer images based on an ultrasound signal corresponding to an object and acquired according to a beam steering operation by the probe1310.

The processor1350may acquire a base image representing brightness levels of regions of the object and a detail image representing details of the regions of the object by performing spatial filtering on each of the plurality of steer images.

The processor1350may respectively set weights of base images for the plurality of steer images, based on the brightness levels for the regions of the object. The processor1350may synthesize the base images for the plurality of steer images according to the weights respectively set for the base images.

The processor1350may respectively set weights for detail images for the plurality of steer images, based on detail levels for the regions of the object. The processor1350may also synthesize the detail images for the plurality of steer images according to the weights respectively set for the detail images.

The processor1350may obtain a synthetic steer image by combining a synthetic base image with a synthetic detail image. The display1330may display the synthetic ultrasound image.

The ultrasound diagnosis apparatuses100described above may be implemented using hardware components, software components, and/or a combination thereof. For example, the apparatuses and components illustrated in the embodiments may be implemented using one or more general-purpose or special-purpose computers, such as a processor, a controller, an arithmetic logic unit (ALU), a digital signal processor, a microcomputer, a field programmable array (FPA), a programmable logic unit (PLU), a microprocessor, or any other device capable of responding to and executing instructions.

A processing device may run an operating system (OS) and one or more software applications running on the OS. The processing device may also access, store, manipulate, process, and create data in response to execution of software.

Although a single processing device may be illustrated for convenience, those of ordinary skill in the art will appreciate that a processing device may include a plurality of processing elements and/or a plurality of types of processing elements. For example, a processing device may include one or a plurality of processors and a controller. In addition, the processing device may have different processing configurations such as parallel processors.

Software may include a computer program, a piece of code, a command, or one or more combinations thereof and independently or collectively instruct or configure the processing device to operate as desired.

Software and/or data may be embodied permanently or temporarily in any type of machine, component, physical equipment, virtual equipment, computer storage medium or device, or in a transmitted signal wave so as to be interpreted by the processing device or to provide commands or data to the processing device. The software may also be distributed over network-coupled computer systems so that the software is stored and executed in a distributed fashion. The software and data may be stored in one or more computer-readable recording media.

The methods according to the embodiments may be implemented in the form of program instructions that may be executed through various computer devices and be recorded on non-transitory computer-readable recording media. The computer-readable recording media may also include, alone or in combination, program instructions, data files, data structures, and the like. The program instructions recorded on the non-transitory computer-readable recording media may be designed and configured specially for the embodiments or be known and available to those of ordinary skill in computer software.

Examples of non-transitory computer-readable recording media include magnetic media such as hard disks, floppy disks, and magnetic tape, optical media such as CD-ROM discs and DVDs, magneto-optical media such as floptical discs, and hardware devices that are specially configured to store and perform program instructions, such as ROM, RAM, flash memory, and the like.

Examples of program instructions include not only machine code made by a compiler but also high-level language code to be executed in a computer by using an interpreter.

The above-described hardware devices may be configured to act as one or more software modules in order to perform operations according to the embodiments, or vice versa.

While one or more embodiments have been described with reference to the figures, it will be understood by those of ordinary skill in the art that various modifications and changes in form and details may be made from the above descriptions without departing from the spirit and scope as defined by the following claims. For example, adequate effects may be achieved even if the above techniques are performed in a different order than that described above, and/or the aforementioned elements, such as systems, structures, devices, or circuits, are combined or coupled in different forms and modes than those described above or are replaced or supplemented by other components or their equivalents.

Thus, the scope of the disclosure is defined not by the above-described embodiments but by the appended claims and their equivalents.