JP5384919B2 - Ultrasonic diagnostic equipment - Google Patents

Description

  The present invention relates to an ultrasonic diagnostic apparatus that stably acquires and displays an elasticity index of a blood vessel or the like.

  In recent years, there has been a rapid increase in the number of patients treated for cardiovascular diseases such as ischemic diseases such as cerebral infarction, myocardial infarction or angina. To prevent these diseases, it is important to detect signs of arteriosclerosis early and improve lifestyle. As a method for non-invasive measurement of arteriosclerotic state, measurement of pulse wave velocity (PWV) and carotid intima-media thickness (IMT) is well known. The clinical diagnostic value is becoming clear.

  IMT is the thickness of the arterial wall having a three-layer structure composed of an intima, an intima and an adventitia. The length to the boundary with the outer membrane). Recent studies have shown that as the arteriosclerosis progresses, the intima-media complex becomes thicker or plaques are formed where the vascular wall rises inward. There are various plaque tissues such as thrombus, fatty or fibrous tissue, and the exfoliated plaque causes carotid artery stenosis, cerebral infarction, cerebral ischemia, and the like. Generally, when IMT is thickened, it can be determined that the plaque is advanced at the initial stage of arteriosclerosis.

  IMT can be measured by ultrasonography (carotid ultrasound). That is, the ultrasonic probe is brought into contact with the neck of the subject (patient), and ultrasonic waves are transmitted from the ultrasonic probe. Ultrasound is reflected at the surface of the structure in the subject (an interface between different tissues), so that the resulting ultrasound echo is received by the ultrasound probe, and an ultrasound image is generated based on the received signal. Is done.

  FIG. 10 is a drawing showing an ultrasonic image of the carotid artery. The IMT can be obtained by determining the vascular lumen intima boundary and medial epicardial boundary in the blood vessel wall from the generated ultrasonic image, and measuring the length between both boundaries using calipers or the like. Furthermore, the examiner (operator such as a doctor) can diagnose the degree of arteriosclerosis based on the IMT, and can estimate the vascular condition of the whole body including the heart and brain based on the result.

  Here, IMT is measured in the carotid artery because the direction of blood flow changes, such as the blood vessel bifurcation between the external carotid artery connected to the facial artery and the internal carotid artery connected to the cerebral artery, and the blood uptake part into the carotid artery. This is because the carotid artery is a frequent site of arteriosclerosis because plaque is easily formed in the region.

  As adopted in Non-Patent Document 1 issued by the Japanese Society of Ultrasound Medicine, a method for determining the risk of arteriosclerosis by measuring the thickness of plaque or the degree of stenosis has been established for IMT measurement. FIG. 11 is a graph showing the relationship between IMT and the risk of stroke shown by O'Leary DH et al. IMT has a clear correlation with the stroke risk rate, and it can be seen that the stroke risk rate increases rapidly when the IMT is 1.1 mm or more.

  However, IMT is an index indicating only the morphological change of the carotid artery, and is not an elastic index indicating blood vessel properties such as pulse wave velocity (PWV). Not appropriate.

  Therefore, in recent years, a method has been developed that uses the carotid artery echo to obtain an elasticity index indicating the properties of the blood vessel, such as the stiffness parameter β, strain, and elastic modulus, by calculation based on the displacement amount of the blood vessel wall. . For example, the pulse wave velocity (PWV) measures the time of heart contraction, detects the pulse wave of the carotid artery and the pulse wave of the femoral artery from the body surface, and determines the propagation time from the heart contraction to the generation of the pulse wave. The calculated speed is a parameter that represents the stiffness of the artery.

  The progression of arteriosclerosis can be quantitatively diagnosed using PWV, and the age of blood vessels can also be estimated. With the emphasis on preventive medicine, PWV has attracted attention as a new preventive medical index that represents the dynamic properties of blood vessels. In recent years, diagnostic devices that easily measure PWV from the pulse waves of the arms and ankles are commercially available. Furthermore, an instrument is also provided that displays a cardiac ankle vascular index (CAVI) that presents a stiffness parameter β, which is the vascular elasticity itself, by measuring PWV.

  FIG. 12 is a graph showing changes in the stiffness parameter β by age, presented by Hiroshi Furudate et al. It can be seen that the stiffness parameter β increases as the age increases regardless of gender. Moreover, it is said that the change of the elasticity index appears before the morphological change like IMT, and is expected to lead to early detection of arteriosclerosis.

  However, elasticity indices such as stiffness parameter β, strain, and elastic modulus need to be tracked for (a) minute displacement of the moving blood vessel wall, and (b) operator shake or subject. (C) When it is difficult to obtain a clear image due to the subject or the like, it is difficult to obtain stable and highly reproducible data. There are problems such as. The main reason why stable data cannot be acquired is that variations in luminance information and phase information, spike-like noise that occurs suddenly, and the like cause erroneous tracking.

  FIG. 13 and FIG. 14 are diagrams showing images for measuring the minute displacement of the carotid artery blood vessel by bringing the ultrasonic probe as shown in FIG. 15 into contact with the neck. The ultrasonic probe shown in FIG. 15 uses an arrayed transducer formed by arranging square bar-shaped transducers on a straight line. The ultrasonic probe having such a configuration can perform linear scanning by moving the position of the ultrasonic beam, that is, the scanning line in a direction perpendicular to the beam direction without moving the probe itself.

In general, in an ultrasound diagnostic apparatus , an ultrasonic echo intensity obtained by intensity-modulating an ultrasonic wave transmitted from a transducer of an ultrasonic probe is developed and displayed in a scanning width direction in a B mode. is referred to as an image, focusing on certain parts of the object, it is called where ultrasound reflection of M-mode images which expand the aging.
FIG. 13 is a diagram illustrating an example of a B-mode image. FIG. 13A shows an image in the i frame, and FIG. 13B shows an image in the j frame. In these B-mode images, line A and line B are indicated by arrows.

  FIG. 14 is a diagram showing an example of an M mode image in which echoes generated in a certain beam direction are displayed over time using the same measurement result as described above. FIG. 14A shows an acquired image in line A, and FIG. 14B shows an acquired image in line B. In these M mode images, an i frame and a j frame are indicated by arrows.

  In the example shown in FIG. 13 and FIG. 14, the data can be stably acquired in the i-frame and the j-frame in the line A, but in the line B, the blood vessel wall image is not obtained due to luminance information, phase variations, and the like. Since it became stable, the data could not be acquired stably, and tracking failed and the elastic index could not be measured stably. Therefore, it is necessary to obtain an elasticity index using data obtained by tracking a line indicating stable data appearing in a B-mode image.

  As a related technique, in Patent Document 1, in order to display an elastic image suitable for diagnosis, an error of the elastic image is evaluated using the luminance information of the tomographic image, and error information is displayed. A method for deleting an elastic image is disclosed. Patent Document 2 discloses an ultrasonic diagnostic apparatus including a calculation unit that obtains a characteristic value (elastic modulus) with time, a stability determination unit that sequentially obtains the stability, and an expression unit that expresses the stability. Is disclosed. Furthermore, Patent Document 3 compares a thickness change waveform indicating a change in distance between measurement sites with a reference waveform, calculates an index indicating the degree of coincidence, and determines the reliability of the maximum thickness change amount and the elastic modulus. A method is disclosed.

  On the other hand, when measuring the displacement of a tissue with an ultrasonic diagnostic apparatus, a method for measuring a displacement of a blood vessel synchronized with a heartbeat by performing M-mode measurement by ultrasonic echo examination of the carotid artery has been known for a long time. Patent Document 4 discloses a method for performing a quick diagnosis by measuring a thickness change from a minute displacement of a blood vessel wall, obtaining an elastic modulus, and identifying the type of biological tissue. Non-Patent Document 1 describes IMT and measurement of arterial diameter as evaluation items for arteriosclerotic lesions. In measuring arterial diameter, the minimum diameter time phase or maximum diameter of an artery that pulsates using the M mode is described. It has been proposed to measure with either cross-sectional image of the time phase.

  Diagnosis using M-mode images is not only familiar to doctors, but also can determine whether or not M-mode images can be acquired stably at the time of examination. There is an advantage that the measurement can be performed again. However, in order to quantitatively measure even a minute displacement of the movement of the blood vessel wall, it is not suitable because the scale of the image range is too different.

As described above, various inventions that enable the operator to acquire reliable data by determining stable data and error data have been disclosed. Since the accuracy of the measurement is too high and it cannot be said that the operator is satisfied with the determination, there is a big problem in stably acquiring the elasticity index.
JP 2007-31958 A International Publication No. 2006/068079 Pamphlet JP 2007-006914 A JP-A-10-711147 "Standard Evaluation Method for Carotid Artery Lesions Using Ultrasound (Draft)" Journal of the Japanese Society of Ultrasonic Medicine (Jpn J Med Ultrasonics) June 2008 Vol. 35 No. 2 p.202-209

  Therefore, in view of the above points, an object of the present invention is to provide an ultrasonic diagnostic apparatus that reliably eliminates unstable data from acquired ultrasonic image information and calculates and displays a correct elasticity index. .

In order to solve the above problems, an ultrasonic diagnostic apparatus according to one aspect of the present invention supplies a plurality of drive signals to an ultrasonic probe including a plurality of ultrasonic transducers that transmit and receive ultrasonic waves, Transmission / reception means for generating reception data by processing a plurality of reception signals output from the probe, storage means for storing reception data generated by the transmission / reception means, and received data stored in the storage means based on, it generates a B-mode image data representing a B-mode image to display the B-mode image on the display unit Rutotomoni, of several that have been set to the multiple positions of the displayed B-mode image on the display unit based on the interest line, read from the storage unit the received data over a predetermined time period at a position corresponding to the plurality of interest lines, M-mode image de representing an M-mode image of the multiple An image data generation means for generating a data Ru display the plurality of M-mode image on the display unit, and sets each a plurality of interest lines to a plurality of positions of the displayed B-mode image on the display unit, the display unit an input unit that is operated to select at least one M-mode image from among a plurality of M-mode images displayed, the elasticity index using the received data corresponding to at least one of the M-mode images selected Elastic index calculation means for calculating.

According to one aspect of the present invention, an ultrasonic diagnostic apparatus to display a B-mode image on the display unit based on the reception data stored in the storage unit, which is set in a plurality of positions of the B-mode image on the display unit based on multiple interest lines to display a plurality of M-mode image, the at least one M-mode image from among those M-mode image is selected, at least one M-mode image selected you calculate the elasticity index using the corresponding received data. Therefore, the operator sets a plurality of attention line in the displayed B-mode image on the display unit, a good M-mode image from among those of the plurality of displayed on the display unit based on the interest line M-mode image Since it can be selected and used to calculate the elasticity index, a stable elasticity index can be obtained.

Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings.
FIG. 1 is a block diagram showing a configuration of an ultrasonic diagnostic apparatus according to one embodiment of the present invention.
The ultrasonic diagnostic apparatus according to the embodiment of the present invention includes an ultrasonic probe unit 200 and an ultrasonic diagnostic apparatus main body 100.

  The ultrasonic probe 200 is a probe used in contact with the surface of an object, such as a convex type, a linear scan type, or a sector scan type. The ultrasonic probe 200 includes a plurality of ultrasonic transducers constituting a one-dimensional or two-dimensional transducer array.

  Each ultrasonic transducer is, for example, a piezoelectric ceramic represented by PZT (Pb (lead) zirconate titanate) or a polymer piezoelectric element represented by PVDF (polyvinylidene difluoride). It is constituted by a vibrator in which electrodes are formed at both ends of a piezoelectric material (piezoelectric body). These ultrasonic transducers transmit ultrasonic waves toward a subject such as a carotid artery based on an applied drive signal, receive ultrasonic echoes reflected from the subject, Output.

  In the ultrasonic diagnostic apparatus main body 100, an input unit 101 such as a keyboard and a pointing device for inputting various information, a transmission circuit 103 and a reception circuit 105 for controlling transmission and reception of ultrasonic waves in the ultrasonic probe 200, and an image are displayed. Display 107, system control unit 111 that adjusts the entire system to perform an appropriate operation, received data memory 113 as storage means for storing received data output from receiving circuit 105, received data An image forming unit 115 that generates image data representing a B-mode image or an M-mode image based on the above, and an elasticity index calculating unit that performs tracking using received data stored in the reception data memory 113 and calculates a target elasticity index 117, an image processor 121 for forming a screen for displaying image data and measurement results Comprising a display processing unit 123 for forming a signal for displaying on the display 107, and screen.

  The system control unit 111 sequentially sets the transmission direction of the ultrasonic beam and the reception direction of the ultrasonic echo of the ultrasonic probe 200 via the transmission circuit 103 and the reception circuit 105, according to the set transmission direction. A transmission control function for selecting a transmission delay pattern and a reception control function for selecting a reception delay pattern according to the set reception direction.

  Here, the transmission delay pattern is a pattern of delay time given to the drive signal of each ultrasonic transducer in order to form an ultrasonic beam in a desired direction by ultrasonic waves transmitted from a plurality of ultrasonic transducers, The reception delay pattern is a pattern of delay time given to a reception signal in order to extract ultrasonic echoes from a desired direction by ultrasonic waves received by a plurality of ultrasonic transducers. A storage device attached to the system control unit 111 stores a plurality of types of transmission delay patterns and a plurality of types of reception delay patterns, which are selectively used according to the transmission / reception direction.

  The transmission circuit 103 includes a plurality of channels, and generates a plurality of drive signals applied to the plurality of ultrasonic transducers. At that time, based on the transmission delay pattern selected by the system control unit 111, respective delay times can be given to the plurality of drive signals. The transmission circuit 103 adjusts the delay amounts of the plurality of drive signals so that the ultrasonic waves transmitted from the plurality of ultrasonic transducers form an ultrasonic beam, and supplies them to the ultrasonic probe 200. Alternatively, a plurality of drive signals configured so that ultrasonic waves transmitted at a time from a plurality of ultrasonic transducers reach the entire imaging region of the subject may be supplied to the ultrasonic probe 200.

  The reception circuit 105 includes a plurality of channels, receives and amplifies a plurality of analog reception signals respectively output from the plurality of ultrasonic transducers, and converts them into digital reception signals. Furthermore, the reception circuit 105 performs reception focus processing by giving each delay time to a plurality of reception signals based on the reception delay pattern selected by the system control unit 111 and adding the reception signals. By this reception focus processing, a reception signal (reception data) in which the focus of the ultrasonic echo is narrowed is formed.

  Next, the receiving circuit 105 performs detection processing such as envelope detection or quadrature detection on the received data, and then reflects the ultrasonic reflection position by STC (Sensitivity Time gain Control). The attenuation due to the distance is corrected in accordance with the depth.

  The orthogonal detection process is a process of down-converting the signals cosωt and sinωt, which have substantially the same angular frequency ω as that of the ultrasonic wave Φ and whose phases are shifted from each other by 90 degrees, with the ultrasonic wave Φ. It is. The measured reception data includes only the real component of the ultrasonic wave Φ, but a complex baseband signal V = x + ji can be generated by performing orthogonal detection processing.

That is, the complex baseband signal V obtained by performing quadrature detection has an I-phase component (real component) x and a Q-phase component (imaginary component) y that are orthogonal to each other, and an amplitude A = (x ² + y ² ) ^1/2 and phase θ = tan ⁻¹ (y / x). Therefore, when quadrature detection is used, a more accurate elasticity index can be calculated based on more information.

  The reception data thus processed is sequentially stored in a reception data memory 113 having a memory capacity for storing reception data corresponding to a plurality of frames of ultrasonic images. The image forming unit 115 receives the received data read from the received data memory 113, and performs a preprocessing process such as logarithmic compression and gain adjustment on the input received data, The image data is generated by performing a scanning line conversion process for converting into image data in accordance with a television signal scanning method, and the generated image data is output to the image processor 121.

  The image processor 121 generates image data representing a screen for displaying an ultrasonic image, a measurement result, and the like based on the input image data, elasticity index data, and the like, and outputs the image data to the display processing unit 123. The display processing unit 123 generates a video signal for displaying a screen and sends it to the display 107, and the display 107 displays a screen including an ultrasonic image and a measurement result.

  In the above, the system control unit 111, the image forming unit 115, the elasticity index calculation unit 117, the image processor 121, the display processing unit 123, and the like are software for causing the central processing unit (CPU) and the CPU to perform various processes. Consists of. The software is stored in a storage unit (not shown). These may be constituted by a digital circuit or an analog circuit.

FIG. 2 is a flowchart for explaining the operation of the ultrasonic diagnostic apparatus according to this embodiment as an example of calculating the stiffness parameter β.
When the operator sets to display the B-mode image and the M-mode image together from the input unit 101 (step S01), the system control unit 111 controls the transmission circuit 103 and the reception circuit 105 so that the neck part is displayed. The abutted ultrasonic probe unit 200 is operated to acquire an ultrasonic image of the carotid artery for a predetermined time.

  The transducer array of the ultrasonic probe 200 is arranged, for example, so that the scanning direction coincides with the blood flow direction of the carotid artery, and captures ultrasonic echoes from the blood vessel walls of the anterior and posterior walls of the blood vessel, and receives the received signals. Output. The reception circuit 105 generates reception data based on the reception signal output from the ultrasound probe 200, and a predetermined amount of reception data generated by the reception circuit 105 is stored in the reception data memory 113.

  Next, the image forming unit 115 starts obtaining the reception data corresponding to the ultrasonic image of the carotid artery from the reception data memory 113 (step S02), and B mode which is tomographic image information regarding the tissue in the subject. Image data is generated, and a B-mode image is displayed on the display 107 via the image processor 121 and the display processing unit 123.

  An operator such as a doctor finds several line positions where received data is not disturbed from one or more displayed B-mode images across the screens, and operates the input unit 101 to display one or more lines of interest. Is set (step S03). The line of interest can be set using a pointing device or the like displayed with the image. The position of the set line of interest is preferably clearly displayed by a vertical line or the like superimposed on the image. For the sake of simplicity, only one B-mode image may be displayed to find a portion in which received data is not disturbed.

  For each set line of interest, the image forming unit 115 reads out reception data over a predetermined period at a position corresponding to the line of interest from the reception data memory 113, and reads M-mode image data over a predetermined period along the time axis. One or more M-mode images corresponding to the line of interest are displayed on the display 107 via the image processor 121 and the display processing unit 123 (step S03). When the operator finds an appropriate screen that can be used for analysis while the displayed image changes over time, the operator operates the input unit 101 to send an instruction signal to the system control unit 111, and the M mode The image screen is frozen (step S04).

  FIG. 3 is a diagram showing an example of an image on the display 107 when the measurement object is the front wall and the rear wall of the carotid artery and the screen is frozen. In FIG. 3, one B-mode image is displayed on the upper side, and two M-mode images are displayed on the lower side. Two lines of interest are set in the B-mode image, the left M-mode image is formed from the received data in the line of interest indicated by the solid line, and the right M-mode image is the line of interest indicated by the dotted line. Is formed from the received data. Information such as measurement conditions is displayed in the upper left part of the screen.

  The right M-mode image shows a disturbance in the inner wall portion, but the left M-mode image is a high-quality image that has little noise and can be used for analysis. In FIG. 3, the M-mode image is displayed only for a period of approximately one beat, but it is more preferable to display the M-mode image for a period of about three beats in order to facilitate the determination. Further, the B-mode image displayed when the screen is frozen may be a timing when the freeze button is pressed, or may be an appropriate timing during one predetermined heartbeat.

  When a plurality of M-mode images are displayed, after the images are frozen, the operator operates the input unit 101 to select an M-mode image used for elastic index measurement (step S05). When the M-mode image to be used is determined, the image forming unit 115 enlarges the M-mode image and displays it on the display 107, and reduces the other images and displays them on the display 107.

  Next, the operator designates a tracking start time and a tracking end time in the M mode image and sets a time range of interest (step S06). Further, the operator sets a tracking point at the blood vessel front wall intima-blood vessel cavity boundary in the M-mode image (step S07), and further sets a tracking point at the blood vessel rear wall blood vessel lumen-intima boundary (step S07). Step S08). The tracking site includes the boundary between the outer membrane and the media in the anterior wall of the blood vessel, the boundary between the intima and the vascular space in the anterior wall of the blood vessel, the boundary between the vascular cavity and the intima in the posterior wall of the blood vessel, and the posterior blood vessel. At least one of the boundary between the media and adventitia in the wall can be included.

  FIG. 4 is a display screen of the display 107 showing a state in which the interest time is set in the M mode image and the tracking point is set. Since the B-mode image at the set time is displayed in real time on the display screen when setting the time of interest, the noise situation can be confirmed.

  Further, the operator operates the input unit 101 to input the maximum blood pressure and the minimum blood pressure measured with the cuff type sphygmomanometer (step S09). These blood pressure values are used as systolic blood pressure Ps and diastolic blood pressure Pd, respectively. In response to this, the elasticity index calculation unit 117 tracks and tracks the luminance change point characterizing the intima-blood vessel cavity boundary from the set tracking point. Tracking can be performed while defining target points by various methods such as tomographic pattern matching method, zero cross point method, tissue Doppler method, phase difference tracking method, etc. Needless to say, any method may be used. Absent.

The elasticity index calculation unit 117 calculates the maximum blood vessel diameter Ds in the systole and the minimum blood vessel diameter Dd in the diastole while tracking the specified region, and calculates the stiffness parameter β from the following equation.
β = {Log (Ps / Pd)} / (Ds / Dd−1)
The calculation result of the stiffness parameter β is displayed near the M mode image on the display screen (step S10).

  FIG. 5 shows a display screen on which the systolic blood pressure Ps and the diastolic blood pressure Pd are input and the stiffness parameter β is displayed. In the M mode image, a trajectory obtained by tracking the intima-blood vessel cavity boundary with respect to the anterior wall and the posterior wall of the blood vessel is displayed. The input blood pressure and the calculated stiffness parameter β are displayed as numerical values. Furthermore, the arteriosclerosis risk and the blood vessel age may be calculated and displayed.

  In addition, using the information of the set tracking part, the IMT (intima-media complex thickness), the blood vessel diameter, the ratio of the minimum blood vessel diameter to the maximum blood vessel diameter, and the like are calculated and displayed on the display unit together with the elasticity index. It may be. FIG. 6 is a diagram showing an example of a display screen on which the IMT value obtained from the tracking part information at the time of interest shown together with the M mode image is shown.

  In general, it is difficult to stably acquire an elasticity index of an organ that moves in synchronization with a heartbeat, such as a blood vessel. However, according to the ultrasonic diagnostic apparatus of this embodiment, a highly reproducible part is selected. Since the elasticity index is calculated using the received data at the place, the elasticity index related to the blood vessel or the like can be obtained stably.

  According to the present invention, before starting tracking for calculating an elasticity index in an ultrasonic diagnostic apparatus, an operator such as a doctor determines whether the data can obtain a reliable elasticity index, or appropriate data. A display screen serving as a convenient interface for selecting a part can be provided. By using the ultrasonic diagnostic apparatus of the present embodiment and calculating an elasticity index such as an elastic modulus that is difficult to obtain stably through a judgment selection by a doctor or the like, the result is more reliable than in the past. Can be obtained.

  In the ultrasonic diagnostic apparatus according to the present embodiment, one of the M-mode images for two lines is selected as the line of interest and the elasticity index is obtained. The elasticity index is calculated by selecting three lines, and the average value thereof may be used as the elasticity index of the blood vessel. In that case, five M-mode images are displayed, and two to three M-mode images are selected from them to obtain the stiffness parameter β, and the instruction screen averages the stiffness parameter β for each M-mode screen. The stiffness parameter β determined in this way is displayed.

  In the ultrasonic diagnostic apparatus according to the present embodiment, the stiffness parameter β is used as the elasticity index, but a strain rate and an elastic modulus can be selected as the elasticity index. However, when calculating the strain rate and the elastic modulus, the thickness of the blood vessel wall, particularly the intima-media thickness (IMT) becomes a problem. Therefore, as shown in FIG. The boundary between the adventitia and media in the anterior wall, the boundary between the intima and the vascular cavity in the anterior wall of the blood vessel, the boundary between the vascular cavity and the intima in the posterior wall of the blood vessel, and the media and the adventitia in the posterior wall of the blood vessel Set at 4 locations on the boundary. From the observed values obtained by tracking the outer membrane-media boundary and the intima-vascular cavity boundary on the front wall and the rear wall, a minute change in the blood vessel thickness is measured, and the maximum value Td and the minimum value of the blood vessel thickness are measured. Ts is obtained.

  Using these values, the strain rate can be obtained by (Td−Ts) / Td, and the elastic modulus E can be obtained by E = (Ps−Pd) / {(Td−Ts) / Td}. it can. When using more sophisticated algorithms, the elastic modulus of each region is measured by dividing the boundary between the outer and medial walls of the anterior and posterior walls and the boundary between the intima and the vascular cavity into multiple sections. You may make it do. In addition, the elasticity index calculation unit 117 calculates at least one of the IMT, the blood vessel diameter, and the ratio of the minimum blood vessel diameter to the maximum blood vessel diameter for the set tracking part, and displays the calculated value together with the elasticity index on the display 107. You may do it.

  In the ultrasonic diagnostic apparatus according to the present embodiment, the position information is represented on the horizontal axis of the M-mode image, but the velocity information may be represented. In that case, the tracking point is set on the B-mode image or is set by displaying the M-mode image including the position information together.

  The tracking point can also be set automatically using the luminance profile at the time of interest selected in the M mode image. FIG. 8 is a diagram showing a brightness profile in the depth direction of received data at the time of interest set in FIG. The left end of the figure is the position of the probe and becomes deeper as it goes to the right.

  FIG. 9 is a diagram for explaining a tracking point automatic determination method. The blood vessel cavity-anterior blood vessel boundary to be selected as the tracking point exceeds the threshold value when the luminance is traced from the position of the blood vessel cavity detected as the black portion in the central portion toward the probe, and further exceeds the peak. The determination can be made based on the point at which the threshold is reached again later. On the other hand, the blood vessel cavity-blood vessel rear wall boundary can be determined based on the point at which the threshold value is first reached when tracing in the direction deeper from the center. Although the same threshold value is used in the figure, the front wall boundary and the rear wall boundary may be determined with different threshold values.

  According to the present invention, in an ultrasonic diagnostic apparatus that generates ultrasonic image data by transmitting ultrasonic waves toward a subject and receiving ultrasonic echoes from the subject, a stable data area from image data displayed on a display Therefore, it is possible to provide an ultrasonic diagnostic apparatus capable of reliably obtaining a stable elasticity index.

1 is a block diagram illustrating a configuration of an ultrasonic diagnostic apparatus according to an embodiment of the present invention. It is a flowchart for demonstrating operation | movement of the ultrasound diagnosing device which concerns on this embodiment. It is drawing which shows the example of an image when a screen is frozen in this embodiment. It is a display screen which shows the state which set the interest time and the tracking point to the M mode image in this embodiment. It is the display screen which displayed the stiffness parameter (beta) in this embodiment. It is the display screen which further displayed IMT in this embodiment. It is drawing showing the example of a display when four tracking points are set in this embodiment. It is drawing which shows the brightness | luminance profile example in the time of interest in this embodiment. It is a diagram explaining the automatic determination method of the tracking point which concerns on this embodiment. It is drawing which shows the ultrasonic image of a carotid artery. It is a graph showing the relationship between IMT and stroke risk rate. It is the graph which looked at the change according to the age of the stiffness parameter β. It is drawing which shows the B mode image which measured the micro displacement of the carotid artery blood vessel wall. It is drawing which shows the M mode image which measured the micro displacement of the carotid artery blood vessel wall. It is a schematic diagram which shows the structure of an ultrasonic probe.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Ultrasonic diagnostic apparatus main body 101 Input part 103 Transmission circuit 105 Reception circuit 107 Display 111 System control part 113 Memory for received data 115 Image formation part 117 Elasticity index calculation part 121 Image processor 123 Display processing part 200 Ultrasonic probe

Claims (7)

A plurality of drive signals are supplied to an ultrasonic probe including a plurality of ultrasonic transducers for transmitting and receiving ultrasonic waves, and reception data is generated by processing a plurality of reception signals output from the ultrasonic probe. Transmitting and receiving means,
Storage means for storing received data generated by the transmission / reception means;
Based on the received data stored in said storage means, to display the B-mode image on the display unit to generate a B-mode image data representing the B mode image Rutotomoni, the displayed B-mode image on the display unit based on the multiple interest lines is set to the position of the multiple reads the received data over a predetermined time period at a position corresponding to the plurality of interest lines from the storage means, representing the M-mode image of the multiple M an image data generation means for Ru to display a plurality of M-mode image on the display unit generates the mode image data,
A plurality of lines of interest are set at a plurality of positions of the B-mode image displayed on the display unit, and at least one M-mode image is selected from the plurality of M-mode images displayed on the display unit. An input unit operated by
And elasticity index calculating means for calculating an elasticity index using the received data corresponding to at least one of the M-mode images selected,
An ultrasonic diagnostic apparatus comprising: The elasticity index calculating means, within the scope of Seki heart time set for at least one M-mode image is selected, to calculate the elasticity index using the received data corresponding to the at least one M-mode image, The ultrasonic diagnostic apparatus according to claim 1. The elasticity index calculating means performs tracking in the range of the interest time for the set tracking sites in at least one M-mode images selected to calculate the elasticity index corresponding to the at least one M-mode image The ultrasonic diagnostic apparatus according to claim 2. The tracking site is a boundary between the outer membrane and the media in the anterior wall of the blood vessel, a boundary between the intima and the blood vessel cavity in the anterior wall of the blood vessel, a boundary between the blood vessel cavity and the intima in the posterior wall of the blood vessel, and comprising at least one of the boundary between the middle and outer membrane, ultrasonic diagnostic apparatus according to claim 3, wherein. The elasticity index calculation means uses the set tracking part information to calculate at least one of IMT (intima-media complex thickness), blood vessel diameter, and ratio of minimum blood vessel diameter to maximum blood vessel diameter. calculated, to be displayed on the display unit together with the elasticity index ultrasonic diagnostic apparatus according to claim 3 or 4, wherein. According pre Me-determined characteristics, further comprising ultrasonic diagnostic apparatus according to claim 3 or 4, wherein the tracking region setting means for setting and automatically selects the tracking sites from within the at least one M-mode image selected . The ultrasonic diagnostic apparatus according to any one of claims 1 to 6, wherein the elasticity index calculation means calculates at least one of a stiffness parameter β, a strain rate, and an elasticity modulus as an elasticity index.