Reference deformable body, ultrasonic diagnostic apparatus, and ultrasonic diagnostic method

An ultrasonic diagnostic apparatus and method are disclosed for enabling identification of a type of reference deformable body. The ultrasonic diagnostic apparatus includes an ultrasonic probe to which the reference deformable body is attached, a tomographic image constructing unit, and a display unit. The ultrasonic diagnostic apparatus further includes a storing unit configured to store the relationship between the ID given to the reference deformable body and a type of the reference deformable body, and a type identifying unit configured to specify the type of the reference deformable body corresponding to the inputted ID. A tomographic image can then be constructed based on the type of reference deformable body specified.

FIELD OF THE INVENTION

The present invention relates to a reference deformable body to be attached on an ultrasonic wave transmission/reception surface of an ultrasonic probe, an ultrasonic diagnostic apparatus and ultrasonic diagnostic method for displaying a tomographic image of an imaging target portion in an object to be examined using ultrasonic waves or an elasticity image which presents hardness or softness of biological tissues.

DESCRIPTION OF RELATED ART

An ultrasonic diagnostic apparatus transmits an ultrasonic wave to the inside of an object to be examined using an ultrasonic probe, receives the reflected echo signal of the ultrasonic wave from the inside of the object according to the structure of the biological tissue, and constructs a tomographic image such as a B-mode image to display for diagnosis.

Ultrasonic diagnostic apparatuses of recent years measure an ultrasonic wave receiving signal by pressing an object using an ultrasonic probe manually or mechanically, acquire displacement of the tissues, and display an elasticity image of the biological tissues based on the acquired displacement data. At this time, the method has been disclosed wherein a reference deformable body is attached to the ultrasonic probe via a fixing member, the border between the object and the reference deformable body is detected from the RF signal frame data acquired by transmission and reception of the ultrasonic waves, and the pressure applied to the object is measured from the positional information of the border (for example, Patent Document 1).

PRIOR ART DOCUMENT

Patent Document

There are various types of reference deformable bodies to be attached to an ultrasonic probe. For example, since there are different sizes or shapes of ultrasonic probes, the size or shape of the reference deformable body best suited to each of those probes would be also different. For a linear-type ultrasonic probe, a linear-type reference deformable body is to be attached. For a convex-type of ultrasonic probe, a curved reference deformable body is to be attached. Also, when depth or size of a measuring portion or physical attribute of the object is different, hardness or thickness of the reference deformable body needs to be changed. In this manner, it is necessary to switch types of the reference deformable body to have optimal feature according to the measurement condition.

However, if the type of the reference deformable body is not identified, elasticity modulus calculation or ultrasonic wave transmission/reception setting cannot be executed properly.

The objective of the present invention is to identify the type of a reference deformable body to be attached to an ultrasonic probe.

SUMMARY OF THE INVENTION

In order to achieve the objective of the present invention, the ultrasonic diagnostic apparatus comprises:

an ultrasonic probe having the ultrasonic wave transmitting/receiving surface on which a reference deformable body is attached;

a tomographic image constructing unit configured to transmit/receive an ultrasonic wave to/from an object to be examined via the reference deformable body, and generate a tomographic image based on the RF signal frame data of the cross-sectional region of the object; and

a display unit configured to display the tomographic image,

characterized in further comprising:

a storing unit configured to store the relationship between an ID given to the reference deformable body and the type of the reference deformable body; and

a type identifying unit configured to read out the type of the reference deformable body corresponding to the ID of the reference deformable body attached to the ultrasonic probe and to identify the type of the reference deformable body. Consequently, the type of the reference deformable body can be identified.

It also comprises an image analyzing unit configured to analyze feature quantity of the reference deformable body in the tomographic image, wherein:

the storing unit stores the relationship between the analyzed feature quantity of the reference deformable body and the type of the reference deformable body; and

the type identifying unit reads out the type of the reference deformable body corresponding to the feature quantity of the reference deformable body in the newly-obtained tomographic image, and identifies the type of the reference deformable body. Consequently, the type of the reference deformable body can be identified.

Furthermore, it comprises an image processing means configured to shift a tomographic image or an elasticity image toward the ultrasonic probe side in accordance with the thickness of the reference deformable body identified in the type identifying unit. Furthermore, it comprises an ultrasonic wave transmission/reception control unit configured to control the focus of the ultrasonic wave in accordance with the thickness of the reference deformable body identified by the type identifying unit, so that the ultrasonic wave will not be focused on the reference deformable body.

In the present invention, the type of a reference deformable body can be identified, and the information thereof can be reflected to calculation of elasticity or displayed.

DESCRIPTION OF REFERENCE NUMERALS

1: ultrasonic wave transmission/reception control circuit,2: transmitting circuit,3: ultrasonic probe,4: receiving circuit,5: phasing and adding circuit,6: signal processing unit,7: black and white scan converter,8: RF signal frame data selecting unit,9: displacement/strain calculating unit,10: elasticity modulus calculating unit,11: elasticity data processing unit,12: color scan converter,13: switching and adding unit,14: image display unit,15: pressure calculating unit,16: reference deformable body,30: reference deformable body information acquiring unit,32: control unit,34: input unit,36: cine memory

DETAILED DESCRIPTION OF THE INVENTION

An embodiment of the present invention will be described referring to the diagrams.FIG. 1shows a block diagram of the ultrasonic diagnostic apparatus related to the present invention. An ultrasonic diagnostic apparatus is for acquiring a tomographic image of a measuring portion in an object to be examined using ultrasonic waves and displaying an elasticity image that presents hardness or softness of biological tissues.

The ultrasonic diagnostic apparatus is Configured comprising ultrasonic wave transmission/reception control circuit1, transmitting circuit2, ultrasonic probe3, receiving circuit4, phasing and adding circuit5, signal processing unit6, black and white scan converter7, RF signal frame data selecting unit8, displacement/strain calculating unit9, elasticity modulus calculating unit10, elasticity data processing unit11, color scan converter12, switching and adding unit13, image display unit14, pressure calculating unit15, reference deformable body16, reference deformable body information acquiring unit30, control unit32, input unit34and cine memory36as shown inFIG. 1.

Ultrasonic probe3is formed by disposing multiple strips of transducers therein, for transmitting and receiving ultrasonic waves to/from an object by scanning beams mechanically or electronically. Each transducer generally has the function that converts incoming pulse waves or continuous transmitting signals into ultrasonic waves and discharges the converted ultrasonic waves, and the function that converts the reflected echoes discharged from inside of the object into electronic signals (reflected echo signals) and outputs the converted signals.

Reference deformable body16is attached on the ultrasonic wave transmitting/receiving surface of ultrasonic probe3. Reference deformable body16is to be applied on the body surface of the object to give compression. Compressing motion renders transmission/reception of ultrasonic waves via ultrasonic probe, and provides stress distribution to the measuring portion in the body cavity.

Ultrasonic wave transmission/reception control circuit1controls the timing or focus for transmitting and receiving ultrasonic waves. Transmitting circuit2produces transmission pulses for generating ultrasonic waves by driving ultrasonic probe3, and sets the convergent point (focus) of the ultrasonic waves transmitted by an internal transmission phasing and adding circuit at a certain depth. Receiving circuit4amplifies the reflected echo signal received by ultrasonic probe3at a predetermined gain. The number of reflected echo signals which corresponds to the number of the amplified respective transducers is inputted to phasing and adding circuit5. Phasing and adding circuit5controls the phase of the reflected echo signal amplified in receiving circuit4, and forms RF signal frame data.

Signal processing unit6and black and white scan converter7are provided on one end of the output side of phasing and adding circuit5. Signal processing unit6inputs the RF signal frame data from phasing and adding circuit5, and executes various signal processing such as gain compensation, log compensation, detection, edge enhancement and filtering.

Black and white scan converter7obtains the RF signal frame data signal processed in signal processing unit6at a predetermined cycle, and reads out the tomographic image data based on the RF signal frame data at TV system cycle.

Also, RF signal frame data selecting unit8, displacement/strain calculating unit9, pressure calculating unit15and elasticity modulus calculating unit10are comprised on the output side of the other end of phasing and adding circuit5. Also, elasticity data processing unit11and color scan converter12are comprised on the latter part of elasticity modulus calculating unit10.

On the output side of black and white scan converter7and color scan converter12, switching and adding unit13is comprised. Image display unit14is a monitor for displaying a tomographic image based on the tomographic image data obtained by black and white converter7and an elasticity image based on the elasticity image data obtained by the color scan converter. Cine memory36on the output side of switching and adding unit13is for storing tomographic image data and elasticity image data with time information. The tomographic image data and elasticity image data stored in cine memory36are displayed on image display unit14according to the command from input unit34.

RF signal frame data selecting8sequentially stores the RF signal frame data outputted from phasing and adding circuit5(the currently stored RF signal frame data is set as RF signal frame data N) in the frame memory provided in RF frame data selecting unit8, selects one set of RF signal frame data from among the past RF signal frame data N−1, N−2, N−3, . . . N−M (the selected data is set as RF signal frame data X), and outputs a pair of RF signal frame data N and RF signal frame data X to displacement/strain calculating unit9. While RF signal frame data is described above as the signal to be outputted from phasing and adding circuit5, it may also be the form of I,Q signal which is the complex-demodulated RF signal.

Displacement/strain calculating unit9executes one-dimensional or two-dimensional correlationship process based on the pair of RF signal frame data selected by RF signal frame data selecting unit8, measures displacement or moving vector (direction and size of displacement) of the respective measurement points on a tomographic image, generates displacement frame data, and calculates the strain from the generated strain frame data. The strain is to be calculated, for example, by performing spatial differentiation on the displacement. The moving vector is to be detected, for example, using the block matching method or the gradient method. Block matching method divides an image into blocks formed by, for example, N×N pixels, searches the block which is most approximated to the target block in the current frame from the previous frame, and performs encoding referring to the searched blocks.

Elasticity modulus calculating unit10calculates elasticity modulus from the strain information outputted from displacement/strain calculating unit9and from the pressure information outputted from pressure calculating unit15, generates numerical data of the elasticity modulus (elasticity frame data), and outputs the generated data to elasticity data processing unit11and color scan converter12. One of elasticity modulus, for example, Young's modulus Ym is to be obtained by dividing the stress (pressure) in each calculation point by the strain in each calculation point, as shown in the equation below. In the equation below, the index of i,j represents the coordinate of the frame data.
Ymi,j=pressure(stress)i,j/(straini,j)(i,j=1, 2, 3 . . . )  [Equation 1]

Here, the pressure given to the object is measured in pressure measuring unit15. Pressure measuring unit15obtains the pressure given to reference deformable body16by calculation, and outputs it as the pressure given to the object. The detail on this step will be described later.

Elasticity data processing unit11executes various image processing such as smoothing process in the coordinate plane of the calculated elasticity frame data, contrast optimization process, or smoothing process among the frames in the time axis direction.

Color scan converter12provides color information on light's three primary colors that are red(R), green(G) and blue(B) to the elasticity frame data outputted from elasticity data processing unit11. For example, large elasticity modulus is converted into red color code, and small elasticity modulus is converted into blue color code.

Also, object pressing mechanism18moves ultrasonic probe3in vertical directions using a device such as motor or wire so as to press the object, or an operator may manually move ultrasonic probe3in vertical direction.

First Embodiment

Manual Input of ID

Here, the first embodiment will be described referring toFIGS. 1˜5. In the first embodiment, an operator inputs an ID to make an ultrasonic diagnostic apparatus to identify the type of a reference deformable body, for reflecting the type to elasticity calculation or displaying the type. This ID is to be the index for identifying the type of the reference deformable body.

The ultrasonic diagnostic apparatus of the first embodiment mainly comprises input unit34configured to input an ID of reference deformable body16, control unit32configured to make the ID inputted by input unit34to be outputted to reference deformable body information acquiring unit30, reference deformable information acquiring unit30configured to acquire the type of reference deformable body16corresponding to the outputted ID and to reflect the type of reference deformable body16to calculation in pressure calculating unit15or elasticity modulus calculating unit10.

First, attachment pattern of reference deformable body16will be described usingFIG. 2. As shown inFIG. 2(a), fixing member17is formed by frame body20having airspace in the center thereof and a pair of holding units21extended downward from the bottom surface of frame body20. Frame body20and holding units21are formed being integrated with each other. On holding unit21, a protruded portion is provided so as to fit in the slot on the side portion of ultrasonic probe3(not illustrated in the diagram). Accordingly, fixing member17can be mounted to ultrasonic probe3through one-touch operation. Also, on the inner-peripheral surface of the airspace in frame body20, slot portion22is provided for holding reference deformable body16. The width of lot portion22is about 3 mm, and the depth thereof is about 5 mm.

As shown inFIG. 2(b), reference deformable body16has a form wherein rectangle body26is provided to the central portion on the upper surface of a square-shaped flat-plate body25. Rectangle body26of reference deformable body16has the size which can be protruded from the airspace in fixing member17. Also, flat-plate body25has about 3 mm of thickness which can be fit in slot portion22of fixing member17.

Reference deformable body16is formed based on oil-based gel material, water-based gel material such as acrylamide or silicon, etc. Acrylamide is formed as acrylamide gel wherein cross-linking agent (BIS) is polymerized in the presence of catalytic agent. This is polymer gel having 3-dimensional meshed structure, and has texture like agar or gelatin. In this manner, the material that is a liquid solution and gets coagulated over time into a gel after coagulating agent is mixed in is preferable for reference deformable body16. If it is constituted by the material such as acrylamide having low viscosity, it is suited for pressure measurement since it responds to pressing operation quickly. Also, reference deformable body16may also be formed by a material based on aqueous resin gelled substance which is to be used as a phantom for diagnosis using ultrasonic waves.

FIG. 2(c) shows a pattern wherein reference deformable body16is attached to fixing member17. The end portion of flat-plate body25is inserted into slot portion22formed on the inner-peripheral surface of frame body20, and reference deformable body16is attached to fixing member17. Since flat-plate body25which is reference deformable body16is an elastic body, flat-plate body25can be mounted in slot portion using the elasticity. Accordingly, when reference deformable body16is attached to fixing member17, rectangle body26of reference deformable body16is protruded from frame body20of fixing member17.

FIG. 2(d) shows the cross-sectional view in the longitudinal direction of the condition that reference deformable body16and fixing member17are fixed on ultrasonic probe3. In the condition that reference deformable body16is attached to fixing member17as shown inFIG. 2(c), fixing member17is fixed on ultrasonic probe3via holding unit22. When fixing member17is fixed on ultrasonic probe3, reference deformable body16comes to contact transducers19provided on the upper part of ultrasonic probe3. In this condition, the upper surface of reference deformable body16is applied to an object, and executes transmission/reception of ultrasonic waves from/to transducers19.

(1-1: ID on a Reference Deformable Body)

Concretely, as shown inFIG. 3(a), ID40formed by letters is appended on the side surface of reference deformable body16. ID40is, for example, “BBAC” formed by four alphabetical letters. ID40is appended on the side surface (the part which does not contact the object) of reference deformable body16to avoid the influence thereof in transmission and reception of ultrasonic waves to/from the object. An operator can identify ID40by the order of alphabetical letters through checking ID40on the side surface of reference deformable body16. ID40may be presented also by numbers, symbols, figures, colors, and so on.

Also, as shown inFIG. 3(b), by providing concavity and convexity for imprinting ID40in advance on a metal mold to form reference deformable body16and inpouring gel material of reference deformable body in the metal mold, ID40formed by concavity and convexity can be formed on the side surface of reference deformable body16. The operator can identify ID40by seeing or touching the concavity and convexity of ID40formed on the side surface of reference deformable body16. Also, surface treatment such as sawtooth or wave pattern may be worked on the side surface of reference deformable body16.

Also, ID40may be identified by dyeing reference deformable body16. For example, if reference deformable body16is white ID40is set as “BBAC”, and if reference deformable body16is yellow ID40is set as “AAAA”.

(1-2: ID on a Package)

As shown inFIG. 3(c), ID40may be appended on case42which is for packaging reference deformable body16. Case42has case part46having airspace therein and cover part44, and reference deformable body16is contained and sealed between case part46and cover part44. By sealing and containing reference deformable body16inside of case42, deterioration of reference deformable body16can be minimized by keeping out dust or air.

The operator can identify the alphabetical letters, i.e. ID40of reference deformable body by seeing ID40on the case for packaging reference deformable body16.

(1-3: Manual Input of ID)

Next, as shown inFIG. 4, the operator inputs ID40of reference deformable body16or ID40described on case42for containing reference deformable body16to input unit34. Control unit32outputs ID40inputted by input unit34to reference deformable body information acquiring unit30, and gives a command to identify the type of reference deformable body16. Then reference deformable body information acquiring unit30identifies the type of reference deformable body16from the outputted ID40, and reflects the type of reference deformable body16to calculation to be executed by pressure calculating unit16and elasticity modulus calculating unit10. Also, reference deformable body information acquiring unit30displays the type of reference deformable body16on image display unit14.

In concrete terms, reference deformable body information acquiring unit30is formed by ID information receiving unit50for receiving the inputted ID40of reference deformable body16, memory52for storing a plurality of relationships between IDs40of reference deformable body16and types of reference deformable body16in advance, and type identifying unit54for identifying the type of reference deformable body16corresponding to the inputted ID40based on the information stored in memory52. Also, in memory52, one type of reference deformable body (such as thickness, elasticity characteristic, acoustic characteristic and type of the probe) is stored corresponding to one ID40as shown in chart 1 below.

Here, the thickness of reference deformable body16is the thickness of reference deformable body in the transmitting/receiving direction of ultrasonic waves, and is the initial thickness before applying pressure. Elasticity characteristics indicate elasticity modulus, viscoelasticity modulus, nonlinearity, Poisson's ratio, etc. of reference deformable body16. In the present embodiment, elasticity modulus is used as elasticity characteristic. Also, acoustic characteristics indicate acoustic velocity, rate of decrease, acoustic impedance, etc. of reference deformable body16. In the present embodiment, acoustic impedance is used as acoustic characteristic. The type of probe indicates the type of ultrasonic probe3to which reference deformable body16is attached. For example, there are different types such as linear type of ultrasonic probe3for pressing from outside of the body or a convex type of ultrasonic probe3, or an intracavitary type of ultrasonic probe3for pressing from inside of the object's body, and the applying part is to be determined.

The four alphabetical letters which indicate ID40respectively correspond to the type of each reference deformable body16. The far-left alphabet corresponds to the thickness of each reference deformable body16. For example, if the far left alphabet is A, it means that the thickness of the reference deformable body is 8 mm, B indicates that the thickness of the reference deformable body is 7 mm, C indicates that the thickness of the reference deformable body is 6 mm, and D indicates that the thickness of the reference deformable body is 5 mm. In this manner, the operator can recognize the thickness of reference deformable body16by only looking at ID40. In the same manner, the second left alphabet corresponds to the elasticity characteristics. The third left alphabet corresponds to the acoustic characteristic, and the far-right alphabet corresponds to the type of ultrasonic probe to which reference deformable body16is attached.

Then kind identifying unit54identifies the kind of reference deformable body16corresponding to the inputted ID40by reading it out from memory52. Input unit34may also input the information on characteristics (for example, elasticity characteristics, etc. of reference deformable body16) of reference deformable body16instead of ID40.

Type identifying unit54outputs the type of reference deformable body16to pressure calculating unit15. Pressure calculating unit15detects the thickness and the elasticity modulus in particular from among the types of reference deformable body16(thickness, elasticity characteristics, acoustic characteristics, type of probe, etc.) outputted from reference deformable body information acquiring unit30. The detected thickness is the initial thickness of reference deformable body16before pressure is applied to the object.

Pressure calculating unit15obtains the strain of reference deformable body16deformed by the pressure applied to the object, from the RF signal frame data outputted from RF signal frame data selecting unit8. In concrete terms, pressure calculating unit15first extracts the RF signal frame data in the region including the border between the object and reference deformable body16. Then it obtains the coordinate of the border between the object and reference deformable body16based on the extracted RF signal frame data. For example, the threshold value is set with respect to the amplitude of the signal wave pattern of the RF signal frame data including the border, the threshold value is set as original point 0 in the depth direction (contact plane of the transducer and reference deformable body16), and the coordinate wherein the amplitude of the waveform of the RF signal frame data first surpasses the threshold value from in the depth direction from the original point is detected as the coordinate of the border.

While the border between the object and reference deformable body16is detected above based on the RF signal frame data, the tomographic image data outputted from black and white scan converter16may also be used for detecting the border.FIG. 5(a) shows the condition of reference deformable body16before pressure is applied on the object.FIG. 5(b) shows the condition of reference deformable body16after pressure is applied on the object. Pressure calculating unit15detects the coordinate of the border in the tomographic image based on the difference of the acoustic characteristics (acoustic velocity, rate of decrease and acoustic impedance) between tissue1and reference deformable body16.

Then pressure calculating unit15associates the initial thickness of reference deformable body16before pressure is applied with the coordinate of the border. Also, pressure calculating unit15calculates the displacement of reference deformable body16from the coordinate of the border after pressure is applied, based on the association between the initial thickness and the coordinate of the border. Pressure calculating unit15then calculates the strain from the calculated displacement and the initial thickness.

Also, elasticity modulus (a part of elasticity characteristics) of reference deformable body16is identified by type identifying unit54based on ID40. Consequently, by setting P as (pressure(stress)), Y as (elasticity modulus) and δd as (strain), their relationship can be expressed by the following equation.
P(pressure(stress))=Y(elasticity modulus)×δd(strain)  [Equation 2]

Pressure calculating unit15can obtain the pressure in the border between the object and reference deformable body16based on the above-mentioned equation 2.

(1-5: Calculation of Elasticity Modulus)

Elasticity modulus calculating unit10calculates elasticity modulus based on the above equation 1 from the strain information outputted from displacement/strain calculating unit9and the pressure information outputted from pressure calculating unit15, and generates numerical data (elasticity frame data) of the elasticity modulus. Elasticity modulus calculating unit10outputs the elasticity frame data to elasticity data processing unit11.

Color scan converter12appends hue information to the elasticity frame data outputted from elasticity data processing unit11, and image display unit14displays the elasticity image based on the elasticity image data acquired by the color scan converter. Though not shown in the diagram, image display unit14may also display the elasticity modulus outputted from elasticity modulus calculating unit10by numerical values.

As described above, in accordance with the present embodiment, it is possible to identify the type of reference deformable body16by ID40, and to reflect the identified information on elasticity calculation, whereby calculation of elasticity can be more stable.

Also, type identifying unit54outputs the type of reference deformable body16or ID40to cine memory36. Cine memory36stores the type of reference deformable body16or the information on ID40along with the elasticity image or tomographic image. Image display unit14outputs the type of reference deformable body16or the information on ID40along with the elasticity image or tomographic image from cine memory36and displays them. In this manner, the type of the reference deformable body or ID40can be displayed.

The operator can execute the setting of ultrasonic waves properly since the type of reference deformable body16or ID40can be identified. Also, after performing the ultrasonic diagnosis, he/she can identify which type of reference deformable body was used for obtaining the elasticity image or tomographic image upon reviewing the elasticity image or tomographic image obtained by applying reference deformable body16.

Also, dedicated information on ultrasonic probe3is appended to ID40as shown in chart 1. Though not shown in the diagram, it is possible to set the procedure to display the warning or to make sounds when reference deformable body16is applied to a nondedicated ultrasonic probe3and transmission/reception of ultrasonic waves is executed.

Second Embodiment

ID Automatic Identification

Here, the second embodiment will be described usingFIG. 6˜FIG.9. The difference from the first embodiment is that ID40of reference deformable body16is automatically identified.

Reference deformable body information identifying unit30is formed by image analyzing unit60configured to the tomographic image stored in cine memory36, memory52configured to store the relationship between a plurality of IDs40of reference deformable body16and feature quantity of the tomographic image of reference deformable body16in advance, and type identifying unit54configured to identify the type of reference deformable body16corresponding to the inputted tomographic image based on the information stored in memory52.

Reference deformable body16includes, for example, a scatterer. Image analyzing unit60analyses the echo luminance in the tomographic image of reference deformable body16in which the scatterer outputted from cine memory36is included. The memory52stores plural echo luminance (0˜255) of reference deformable body16by associating them with ID40respectively. For example, as shown in chart 2, it is assumed that there are two kinds (ID40: α,β) of reference deformable bodies16having different elasticity modulus or scatterer concentration that are stored in memory52. It is also assumed that the ultrasonic waves are transmitted/received to/from the respective reference deformable bodies16in the same condition.

FIG. 7are tomographic images in the case that reference deformable body16(α,β) in which scatterer is included is attached.FIG. 7(a) is a tomographic image in the case that reference deformable body16having α as ID40is attached, andFIG. 7(b) is a tomographic image in the case reference deformable body16having β as ID40is attached.

The echo luminance of reference deformable body16is displayed in the region where is shallow in depth (for example, 0˜5 mm) in the tomogaphic image. Image analyzing unit60analyzes the echo luminance in the shallow region of the tomographic image stored in cine memory36. For example, image analyzing unit60sets ROI70in reference deformable body16of the tomographic image, and analyzes the luminance information in ROI70. This ROI70is set via input unit34as one chooses. Also, it may be set so that ROI70is automatically set in the region which is shallow in depth (for example, 0˜5 mm) in the tomographic image.

Image analyzing unit60analyzes statistical characteristics of the echo luminance such as the average value or dispersion value of the echo luminance in ROI70. Then type identifying unit54reads out the type of reference deformable body16corresponding to the characteristics of the echo luminance in the analyzed tomographic image from memory52and identifies it.

In concrete terms, if the average value of the echo luminance in ROI70is “50”, type identifying unit54identifies that ID40of reference deformable16is α. Also, if the average value of the echo luminance in ROI70is “100”, type identifying unit54identifies that ID40of the reference deformable body is β.

Then type identifying unit54outputs the type (here, elasticity modulus, scatterer concentration, echo luminance and thickness) or ID40of reference deformable body16to cine memory36. Cine memory36stores the information on the type or ID40of reference deformable body16along with the elasticity image or tomographic image. Image display unit14outputs the information on the type or ID40of reference deformable body16along with the elasticity image or tomographic image from cine memory36, and displays them. Accordingly, the operator can identify the type or ID40of reference deformable body, and set ultrasonic waves appropriately. Also, he/she can identify the type of reference deformable body16used for obtaining the elasticity image or tomographic image.

Also, as in the same manner as the first embodiment, elasticity modulus may be calculated based on the type of reference deformable body16. Type identifying unit54outputs the type of reference deformable body16to pressure calculating unit15, and pressure calculating unit15calculates the pressure. Then elasticity modulus calculating unit10calculates elasticity modulus from the strain information outputted from displacement/strain calculating unit9and the pressure information outputted from pressure calculating unit15, and generates the numerical data (elasticity frame data) of the elasticity modulus. Image display unit14displays the elasticity image or elasticity modulus based on the generated elasticity frame data.

While the type of reference deformable body16is identified above from the average value of the echo luminance in reference deformable body16, there are cases, for example, that approximately average echo luminance is distributed even when the scatterer concentration of reference deformable body16is greatly different.

Given this factor, type identifying unit54may identify the type of reference deformable body16from attenuation characteristic of reference deformable body16. Attenuation characteristic is the feature that ultrasonic waves attenuate in proportion to the scatterer concentration. Image analyzing unit60analyzes the attenuation characteristics from distribution of the intensity of echo luminance in reference deformable body16. The intensity of echo luminance in reference deformable body16has the characteristic that it attenuates as moving from the shallow depth portion to the deep portion.

When the ultrasonic waves having low transmitting voltage are transmitted/received to/from ultrasonic probe3and the scatterer concentration of reference deformable body16is high, attenuation rate is great and the intensity of echo luminance attenuates drastically. ID40in this condition is set as α. Also, when the ultrasonic waves having high transmitting voltage are transmitted/received to/from ultrasonic probe3and the scatterer concentration is low, attenuation rate is small and the intensity of echo luminance attenuates gradually. ID40of this reference deformable body16is set as β. The relationship between the attenuation of reference deformable body16and ID40is stored in memory52.

Image analyzing unit60analyzes the attenuation rate from the distribution of the intensity in echo luminance of the scatterer in ROI70. Then type identifying unit54reads out and identifies the type of reference deformable body16corresponding to the attenuation rate from memory52. Type identifying unit54, in the case that the attenuation rate in ROI70is high, identifies that ID40of reference deformable body16is α. In the case that the attenuation rate in ROI is low, it identifies that ID40of reference deformable body16is β.

(2-3: Pattern of Scatterer)

Also, type identifying unit54may identify the type of reference deformable body16from density distribution (rarefaction density) of scatterer in reference deformable body16.

For example, in the case that density distribution of the scatterer of reference deformable body16gets higher as it moves from the shallow region to the deep region, ID40of reference deformable body16is set as α. In the case that the density distribution of the scatterer of reference deformable body16gets lower as it moves from the shallow region to the deep region, ID40of reference deformable body16is set as β. The relationship between the scatterer distribution of reference deformable body16and ID40is to be stored in memory52.

Image analyzing unit60analyzes density distribution of the scatterer from the echo luminance in ROI70. Then type identifying unit54reads out and identifies the type of reference deformable body16corresponding to the density distribution of the analyzed scatterer from memory52.

Type identifying unit54, in the case that the echo luminance in ROI70gets lower as it moves from the shallow region to the deep region, identifies that ID40of reference deformable body16is α. Type identifying unit54, in the case that the echo luminance in ROI70gets higher as it moves from the shallow region to the deep region, identifies that ID40of reference deformable body16is β. Type identifying unit54may also identify the type of reference deformable body16based on discreteness (dispersion in normal distribution) of the echo luminance distribution in the scatterer of reference deformable body16.

(2-4: Size and Form of Scatterer)

Also, deformable body type identifying unit54may identify the type of reference deformable body16from the size of the scatterer. For example, when the size of the scatterer included in reference deformable body16is 5 μm, ID40of reference deformable body16is set as α. When the size of the scatterer included in reference deformable body16is 10 μm, ID40of reference deformable body is set as β. At this time, it is to be assumed that a plurality of scatterers having even size are included in reference deformable body16. The relationship between the size of the scatterer in reference deformable body16and ID40is stored in memory52.

Image analyzing unit60analyzes the size of the scatterer from echo luminance in ROI70. Then type identifying unit54reads out and identifies the type of reference deformable body16corresponding to the size (5 μm or 10 μm) of the analyzed scatterer. Also, deformable body type identifying unit54can also identify the form of the scatterer in reference deformable body16using the pattern matching method. It is set so that the form of the scatterer is different for each ID40of reference deformable body16.

The relationship between the form of the scatterer of reference deformable body and ID40is stored in memory52. Image analyzing unit60analyzes the form of the scatterer from the echo luminance in ROI70. Then type specifying unit54executes the pattern matching method between the form of the scatterer stored in memory54and the form of the analyzed scatterer. Type identifying unit54reads out and identifies the type of reference deformable body16including the best matched scatterer stored in the memory.

(2-5: Layer and Barcode)

Also, deformable body type identifying unit54may identify the type by the pattern or barcode of reference deformable body16. As shown inFIG. 8, reference deformable body16is assumed to be formed by a plurality of different kinds of layers (layer1and layer2). Layer1is on the side of ultrasonic probe3, and layer2is on the side of the object.

As shown inFIG. 8(a), in the case that the ratio between layer1and layer2of reference deformable body16is (layer1:layer2=1:2), ID40of reference deformable body16is set as α. As shown inFIG. 8(b), in the case that the ratio thereof is (layer1:layer2=1:1), ID40of reference deformable body is set as β. The relationship between the ratio between the layers of reference deformable body16and ID40is stored in memory52.

Image analyzing unit60analyzes the ratio between layer1and layer2of reference deformable body16from the echo luminance of an elasticity image. In concrete terms, image analyzing unit60detects the border between layer1and layer2, and the border between layer2and tissue1based on the echo luminance. Then image analyzing unit60detects the height of layer1and layer2in the depth direction from the respective borders. Type identifying unit54then reads out and identifies ID40of reference deformable body16corresponding to the detected ratio between layer1and layer2from memory52.

Also, as shown inFIG. 9, it is assumed that mark72formed by barcodes is appended to the side of reference deformable body16. As shown inFIG. 9(a), in the case that reference deformable body16includes one strip of barcode, ID40of reference deformable body16is set as α. As shown inFIG. 9(b), in the case that reference deformable body16includes two strips of barcodes, ID40of reference deformable body16is set as β. The relationship between the number of strips in barcode and ID40of reference deformable body16is stored in memory52. The echo luminance of barcode should be different from the echo luminance of reference deformable body16. The array direction of the barcode is the major-axis direction or minor-axis direction of reference deformable body16.

Image analyzing unit60analyzes the number of strips of barcode in reference deformable body16from the echo luminance of the elasticity image. Then type identifying unit54reads out and identifies ID40of reference deformable body16corresponding to the analyzed number of strips of barcode from memory52.

While barcode is used as mark72here, a concave portion or notch may also be used. Also, by stretching a very thin string (for example, a fish line) inside of reference deformable body16along the minor-axis direction of reference deformable body16, the information on the number of the strings or interval between the strips may be also used as mark72.

Third Embodiment

Image Processing

The third embodiment will now be described referring toFIGS. 10 and 11. The difference from the first embodiment and the second embodiment is that image processing is executed by identifying the type of reference deformable unit16.

As shown inFIG. 10, reference deformable body information acquiring unit30has image processing unit62for executing image processing with respect to the tomographic image (or elasticity image) stored in cine memory36, in addition to the above-described image analyzing unit60, memory52and type identifying unit54.

As shown inFIG. 11, image processing unit62shifts the tomographic image toward the upper direction (the side of ultrasonic probe3) according to the “thickness” of reference deformable body16so as not to display reference deformable body16.FIG. 11(a) shows the tomographic image before the correction, andFIG. 11(b) shows the tomographic image after the correction.

In concrete terms, as shown in Chart 1, if ID40identified in type identifying unit54is AAAA, the thickness of reference deformable body16is 8 mm. Image processing unit62loads the thickness information of the reference deformable body from type identifying unit54, and shifts the tomographic image stored in cine memory36in the upper direction by 8 mm. If ID40is BAAA, the thickness of reference deformable unit16is 7 mm. Image processing unit62loads thickness information of the reference deformable body from type identifying unit54, and shifts the tomographic image stored in cine memory36in the upper direction by 7 mm.

In this manner, as shown inFIG. 11(b), since reference deformable body16is not displayed on image display unit14, it is possible to broaden the display region of tissue5in the deep portion.

Fourth Embodiment

Focus Only on the Thickness Portion

Here, the fourth embodiment will be described. The difference from the first embodiment˜the third embodiment is that transmission and reception of ultrasonic waves is controlled by identifying ID40of reference deformable body16.

In the present embodiment, though not shown in the diagram, reference deformable body information acquiring unit30is connected with ultrasonic-wave transmission/reception control circuit1.

Type identifying unit54outputs ID40of reference deformable body16(includes thickness, elasticity characteristics, acoustic characteristics, kind of probe, etc.) to ultrasonic-wave transmission/reception control circuit1. Ultrasonic-wave transmission/reception control circuit1detects “thickness” from ID40. Then ultrasonic-wave transmission/reception control circuit1controls focus of the ultrasonic waves according to the thickness so that the ultrasonic waves will not be focused on reference deformable body16.

In concrete terms, as shown in Chart 1, if ID40identified in type identifying unit54is AAAA, the thickness of reference deformable body16is 8 mm. Ultrasonic-wave transmission/reception circuit1loads the thickness information of the reference deformable body from type identifying unit54, and controls transmission circuit2and receiving circuit4so that ultrasonic waves will be focused at the depth deeper than 8 mm to avoid ultrasonic waves from being focused on reference deformable body16.

Accordingly, since ultrasonic waves are focused on tissues1˜5of the object, image display unit14can display the tomographic image appropriately.