JPH10151133A - Medical imaging system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable the biological determination with high accuracy and with high reliability by providing a motional information obtaining means to obtain motional information on a reference part on an image and a moving distance operation means to perform an operation on a moving distance of an ROI position with every frame, and controlling the ROI position with every frame by using the moving distance by performing the operation. SOLUTION: An image memory unit 17 has a frame memory to primarily store image data on plural obtaining modes, and writes and reads the image data in response to a control signal. A biological determination instrument 18 measures biological information in a target time phase range with every frame in response to the supplied control signal, and sends measuring data to a data synthesizer 21. A moving distance computing element 19 performs an operation on a moving distance of a reference ROI as a reference part set on an image screen by an operator with every frame in the interested time phase range, and this movement control signal is outputted to an ROI generator 20, and graphic data of an ROI wished to be set on a display image is generated here, and a position on its image screen is adjusted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ROI on an image obtained by time-series ultrasonic scanning of a tomographic plane in a subject.
The present invention relates to a medical image diagnostic apparatus that obtains biometric information in an ROI, and particularly relates to time-series movement control of the ROI. In addition, this medical image diagnostic apparatus is often formed as an ultrasonic diagnostic apparatus having such a function of measuring a living body.

[0002]

2. Description of the Related Art In recent years, various types of ultrasonic images, such as a luminance image of a tomographic image of a subject and a blood flow image, have been obtained abundantly. The importance of quantitative measurement of image information is increasing. The measurement items include various items such as blood flow information of a living body, image signal intensity (luminance), area, and volume.

[0003] In order to evaluate the function of a subject, it is often the case that changes over time of the measurement items are observed. In such a case, the entire image is rarely set as a measurement target, and a specific region of interest on the image is specified, and the time change of the biological information in the specific region is observed and measured. In order to indicate this specific area, usually, the ROI (region of in
terest: region of interest).

Specifically, for example, first, time-series image data for each frame of a B-mode tomographic image of a subject is obtained by an ultrasonic diagnostic apparatus as a medical modality, and this image data is stored in an image memory of the medical image diagnostic apparatus. Is stored in The examiner designates image data of a period of interest (POI) in the time-series image data, and sets an ROI for biometric measurement on an image of a certain frame. The time-series image data of the time phase range of interest is displayed on a monitor at an appropriate frame rate, and biological information (for example, luminance change information to be applied to a time density curve) based on the image data in the ROI for the image data of each frame. Are calculated in time series.

[0005]

However, in image diagnosis using the above-mentioned conventional biometric method, although the position of the ROI set on the image is fixed on the monitor screen, the movement of the tissue (i.e. Contraction or expansion), the position of the display target itself moves relatively,
As the image is updated, the position of the ROI often shifts from a specific location on the display target that the inspector originally intended. When such a situation occurs, RO
Either the time-series biological information based on the image data in I cannot be accurately measured, or the reliability of the measurement result is extremely low.

In order to improve this problem and measure with high accuracy, as one countermeasure, it is necessary to manually correct the position of the ROI for each frame in the time phase range of interest. However, this requires that the mouse operation for freezing the display frame and moving the ROI be repeated for each correction frame, and the amount of operation occupies a large weight for image diagnosis and complicates the operation. For this reason, the operation time is prolonged, that is, the time required for the image diagnosis is prolonged, and the throughput of the image diagnosis is reduced, and the operation labor of the inspector (operator) is significantly increased. Also, since the position of the ROI is manually corrected,
Due to the fact that it is easy to cause frames to be forgotten to correct,
The reliability of the measurement results was also insufficient. On the other hand, if a highly reliable measurement is to be performed, such manual correction requires considerable skill, and there is also a problem that the operator lacks flexibility in terms of eligibility.

As a convenient method for alleviating the above-mentioned basic problem, it is conceivable to set a wide ROI in advance in consideration of the displacement of the ROI for measuring a living body. However, such a wide setting results in a compromise setting in which a part that is not particularly interesting is included in the ROI in advance, and there is a problem that both reliability and accuracy of the measurement result are unsatisfactory.

[0008] The present invention has been made in view of the above-described problem of the conventional ROI usage method, and in particular, to make an ROI for biometric measurement accurately follow an initially intended portion even when there is tissue movement. Accordingly, it is an object of the present invention to provide an image diagnostic apparatus that enables highly accurate and highly reliable biological measurement and that can significantly reduce operation labor.

[0009]

In order to achieve the above object, a medical image diagnostic apparatus according to one aspect of the present invention comprises a plurality of time-series frames obtained by scanning a cross section inside an object with an ultrasonic signal. An apparatus for measuring biological information of an ROI (region of interest) set on an image based on the image data based on the image data of the minute; Movement amount calculation means for calculating the movement amount of the position of the ROI for each frame based on information; and position control means for controlling the position of the ROI for each frame using the movement amount calculated by the movement amount calculation means. And characterized in that:

According to another aspect of the present invention, there is provided a medical image diagnostic apparatus comprising: a storage unit configured to store a plurality of time-series image data obtained by scanning a cross section inside an object with an ultrasonic signal; Display means for displaying, on a monitor, image data of an arbitrary frame among the image data of the plurality of frames,
A movement information obtaining unit for obtaining movement information of a reference portion on the image displayed on the monitor; and a biometric R on the image.
ROI setting means for setting an OI (region of interest); movement amount calculation means for calculating the movement amount of the position of the ROI with respect to the image data of the remaining frames for the plurality of frames based on the movement information of the reference region; Position control means for controlling the position of the ROI on the display image of the image data of the remaining frame using the movement amount calculated by the movement amount calculation means; and an image in the ROI based on the image data of the plurality of frames. Measuring means for measuring biological information based on data.

As a preferred example, the storage means, the display means, the movement information acquisition means, the ROI setting means, the movement amount calculation means, the position control means, and the measurement means are integrated into an ultrasonic diagnostic apparatus. Mounted on Thus, the apparatus can be used as the medical image diagnostic apparatus of the present invention while being used as an ultrasonic diagnostic apparatus.

[0012] For example, the position of the ROI for living body measurement and the position of the reference site coincide. In this case, the ROI for living body measurement and the reference site are commonly located in a part of a tissue such as a myocardium.

Further, for example, there is provided a reference part designating means for designating the position of the reference part independently of the position of the ROI for living body measurement. In this case, the reference site is a part of a tissue such as a myocardium of the subject, and the biometric R
The location of the OI is at the blood flow site.

[0014] More preferably, a data designating means for designating image data of a frame in a time phase range of interest out of the image data for a plurality of frames is additionally provided in the apparatus of the above two aspects.

The moving amount calculating means may be formed, for example, as means for estimating and calculating the moving amount from image data of two temporally adjacent frames of the remaining frames of the plurality of frames. Further, the movement amount calculating means may be formed as means for estimating and calculating the movement amount via a function from image data of a plurality of frames in the remaining frames of the plurality of frames. Further, the moving amount calculating means may be formed to include a correcting means for correcting the image data in accordance with an angle difference between the direction of the ultrasonic signal and the direction of the movement of the reference part.

[0016] More preferably, the apparatus may further comprise a manual adjusting means capable of manually adjusting the position of the ROI controlled by the position control means.

Further, for example, a plurality of the ROIs may be set by the ROI setting means.

With the above-described various aspects and modifications, the position of the ROI for measuring the living body set on the ultrasonic image can be controlled in accordance with the movement of the tissue so that the desired position on the living body can always be followed. it can. Therefore, it is possible to accurately exclude the fact that the living body measurement is performed based on the inappropriate image data, and it is possible to perform the highly accurate and highly reliable living body measurement. In addition, the labor required for the operation of the inspector can be significantly reduced.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the accompanying drawings.

First, an outline of the configuration of the medical image diagnostic apparatus according to the present embodiment will be described.

The medical image diagnostic apparatus is integrated with the ultrasonic diagnostic apparatus shown in FIG. 1, and is capable of both acquiring various ultrasonic images and performing medical image diagnosis represented by biological measurement. Can be done. Hereinafter, an ultrasonic diagnostic apparatus functionally equipped with the medical image diagnostic apparatus will be described.

The ultrasonic diagnostic apparatus shown in FIG. 1 has an ultrasonic probe 1 capable of bidirectional signal conversion between an ultrasonic signal and an electric signal, a transmission system circuit 2 connected to the ultrasonic probe 1, and a receiving circuit. System circuit 3, a processing / operation system circuit 4 for image data and biological measurement information provided on the output side of the reception system circuit 3, a display system circuit 5 provided on the output side of the processing / operation system circuit 4, and A control system circuit 6 for controlling operation and processing of the entire apparatus.

The ultrasonic probe 1 has an array type piezoelectric vibrator disposed at the tip thereof. The array type vibrator has a plurality of piezoelectric elements arranged in parallel and the arrangement direction thereof is used as a scanning direction, and each of the plurality of piezoelectric elements forms a transmission / reception channel.

Although not shown, the transmission system circuit 2 includes a pulse generator for generating a reference rate pulse, and a transmission for generating a drive pulse by delaying the reference rate pulse output from the pulse generator for each channel. And a circuit.
The drive pulse for each channel output from the transmission circuit is
It is supplied to each of the plurality of transducers of the ultrasonic probe 1. The transmission delay time of the drive pulse is controlled for each channel and is supplied repeatedly for each rate frequency. An ultrasonic pulse is emitted from each transducer in response to the supply of the drive pulse. The ultrasonic pulse forms a transmission beam due to a controlled transmission delay time while propagating in the subject, and reflects a part of the ultrasonic beam on a boundary surface having a different acoustic impedance to become an echo signal. Some or all of the returned echo signals are received by one or more transducers and converted to corresponding electrical signals.

Although not shown, the receiving system circuit 3 includes a preamplifier for each channel connected to each transducer of the probe 1, a delay circuit connected to each of the preamplifiers and capable of changing a delay time, An adder for adding the delay output of the circuit. For this reason, in the echo signal received by the probe 1, after the analog signal of the corresponding electric quantity is taken into the receiving system circuit 3, and amplified for each channel, the echo signal is subjected to delay control for receiving focus and added. . As a result, a reception beam having a focus point determined according to the control of the reception delay time is arithmetically formed, and a desired directivity can be obtained.

The output terminal of the receiving circuit 3 is connected in parallel to a B-mode processing circuit 11, a CFM mode processing circuit 12, a TDI mode processing circuit 13, and a PWD mode processing circuit 14. These processing circuits 11 to 14 constitute a part of the processing / arithmetic circuit 4. The processing / arithmetic circuit 4 includes a processing circuit 11 for each image data acquisition mode.
14, an electronic changeover switch 15, a digital scan converter (DSC) 16, and an image memory unit 1 provided on the output side of these processing circuits 11 to 14.
7, a biological measuring device 18, a movement amount computing device 19, a ROI generator 20, and a data synthesizer 21.

The B-mode processing circuit 22 is responsible for generating B-mode black-and-white tomographic image data, and includes a logarithmic amplifier, an envelope detector, and an A / D converter (not shown). I have. For this reason, the echo signal subjected to phasing addition in the receiving system circuit 3 is logarithmically compressed and amplified by the logarithmic amplifier, and
The envelope of the amplified signal is detected by an envelope detector, further converted into a digital signal by an A / D converter, and output as B-mode image data.

The CFM mode processor 12 is constituted by a conventionally well-known circuit for two-dimensionally detecting blood flow information in a color flow mapping (CFM: a type of color Doppler tomography) mode. Although not specifically shown, the CFM mode processor 12 includes a quadrature phase detector, an A / D
It includes a converter, an MTI filter, and an autocorrelator, and also includes an average speed calculator, a variance calculator, and a power calculator that perform calculations based on the autocorrelation output. A Doppler signal is detected from the received echo signal by a quadrature phase detector. The Doppler signal is converted into digital data by an A / D converter, and then temporarily stored in a frame memory of an MTI filter.

In the CFM mode, the same cross section is ultrasonically scanned a plurality of times in order to obtain blood flow information. Therefore, the frame memory has three dimensions of a beam scan direction, an ultrasonic beam direction, and a scan number direction. Is stored. The MTI filter includes a high-pass filter on the reading side of the frame memory. For this reason, of the image data having three dimensions, the Doppler component of the tissue echo is removed from each of a plurality of Doppler data strings in the scan frequency direction corresponding to each pixel position, so that the Doppler component of the blood flow echo is good. Is extracted.

The high-pass filtered Doppler data train analyzes the average Doppler frequency of the data train in a self-operation unit. Based on this average Doppler frequency, the average velocity calculator calculates the blood flow average velocity at each sample point on the scan section, the variance calculator calculates the variance of the blood flow velocity distribution, and the power calculator calculates the echo signal from the blood flow. Each power value is calculated. These pieces of calculation information are output as color Doppler information.

Further, the TDI mode processing circuit 13 two-dimensionally detects tissue motion information by tissue Doppler imaging (TDI: a type of color Doppler tomography). The configuration of the TDI mode processing circuit 13 is roughly the same as the C
It is the same as the FM mode processing circuit 12, but the characteristics of the filter circuit provided in the MTI filter are set so that the Doppler component of the echo signal from the tissue such as myocardium can be extracted. That is, the characteristic is based on the difference between the intensity and the Doppler shift frequency (motion speed) between the tissue echo signal and the blood flow echo signal.
Although the intensity of the tissue echo signal is large compared to that of the blood flow, the Doppler shift frequency (ie, velocity) is usually small. For this reason, the filter circuit mounted on the MTI filter is configured as a low-pass filter that can extract the low frequency Doppler shift frequency. Other configurations are the same as those of the CFM mode processing circuit 12.

Further, the PWD mode processing circuit 14 has a function of generating Doppler spectrum data based on the pulse Doppler (PWD) method. Specifically, it includes a quadrature phase detector, a sample and hold circuit, a bandpass filter, an A / D converter, an FFT, and the like.

Further, the changeover switch 15 is configured to have a contact made of an electronic switching element for switching a path according to an operation mode of the apparatus in response to a control signal. As this contact, three normally open contacts aa ', bb', and cc 'that operate on and off are provided. The contacts aa 'are connected to the four processing circuits 11 to 14 described above.
And the DSC 16 are connected to connect them in common. Another contact point bb ′ is interposed between the four processing circuits 11 to 14 and the image memory unit 17. The remaining contacts cc 'are connected to the image memory unit 17 and the DSC 16
It is interposed between.

In the ultrasonic diagnostic apparatus also serving as the image diagnostic apparatus, the operation modes include a "normal display mode" for functioning as a normal ultrasonic diagnostic apparatus, and a "data storage" for temporarily storing image data based on an ultrasonic scan. A "mode" and a "measurement mode" for measuring biological information based on the temporarily stored image data are provided. When the "normal display mode" is commanded, only the contacts aa 'of the changeover switch 15 are turned on and the other contacts bb' and cc 'are turned off by the control signal. When instructing the “data storage mode”, the contact b
Only -b 'is on, and the other contacts aa', cc '
Is switched off. When instructing the "measurement mode", only the contacts cc 'are turned on, and the other contacts a-
a 'and bb' are switched off. More preferably, it is desirable that the latest image is always automatically stored in data even under the "normal mode".

The DSC 16 has a frame memory 16a, and changes the scanning method by controlling writing and reading to and from the frame memory 16a.

The image memory unit 17 has a plurality of frame memories for temporarily storing image data in a plurality of acquisition modes, and performs writing and reading of the image data in response to a control signal. Has become.

The biological measuring device 18 is constituted by having a dedicated processor, for example. The biometric device 18 measures biometric information in a time phase range of interest for each frame in response to the supplied control signal. This measurement data is sent to the data synthesizer 21. The term “measurement” here refers to measurement of various living body diagnostic information (biological information) based on blood flow velocity information, tissue movement velocity information, and ultrasonic scattering intensity (luminance) information. As biological information, for example,
There are a distance, an area, a volume, a speed, a blood flow rate, a luminance value used for a time density curve, and the like.

The moving amount calculator 19 is formed as a dedicated processor, for example. Thereby, the movement amount calculator 1
Reference numeral 9 denotes a moving amount (moving direction and moving distance) of the reference ROI as a reference portion set on the screen by the operator for each frame (that is, over time) in a period of interest (POI: Period of interest). Calculate. The calculated movement amount is converted into a movement control signal and output to the ROI generator 20. As will be described later, this movement amount is a control amount for controlling the position on the ROI image for the set biological information measurement (that is, on the two-dimensional image data stored in the frame memory).

Here, a method of estimating the movement amount of the reference part will be described. The simplest method is to determine the amount of movement between two consecutive frames using the movement speed of the reference part one frame before as shown in FIG. As shown in the figure,
It is assumed that a reference ROI: ROIref indicating a reference site is set on the tissue of the image. Reference ROI: ROI
Assuming that the speed at time t one frame before ref is V (t), the movement amount dx is a value obtained by multiplying this speed V (t) by the frame interval time dT, that is,

Dx = V (t) · dT (1) However, in the case of the Doppler method, the speed is usually detected as a component Vd in the scanning line direction, so that an angle correction is required when taking the moving direction into account. Assuming that the angle between the direction of the scanning line and the movement direction of the reference ROI: ROIref is θ, and the actual movement speed is V (t),

Since Vd = V (t) · cos θ (2), the angle-corrected movement amount dx is

(Equation 3) Is required.

The angle correction when the object to be imaged is a heart will be described. In the case of the left ventricular short-axis view, the motion of the heart is
The movement is substantially concentric with the contraction center of the point. Using this property, angle correction can be performed as follows. The first method is to use an angle marker (for example, an arrow or a line) as shown in FIG. The obtained movement amount dx is obtained. In the second method, a contraction center O of the myocardium is specified on the image, a scan line passing through the reference ROI: ROIref, and the reference ROI: ROIref and the contraction center O.
Is determined with respect to the motion direction connecting the two, and the motion speed V (t) of the reference ROI: ROIref is obtained from equation (2). Thereby, the movement amount dx whose angle has been corrected can be obtained from the equation (3a). Movement direction is the reference part ROI
This is the direction of movement connecting ref and the contraction center O.

For example, assuming that the frame rate is 40 Hz and the moving speed V (t) of the reference ROI: ROIref as a reference portion (tissue) is 100 mm / s, the moving distance of the reference ROI: ROIref between frames is 25 msec. ×
100 mm / s = 2.5 mm.

Further, another method of estimating the movement amount uses speed information of a plurality of frames. For example, the reference ROI: RO at the sampling interval (frame interval time dT)
Assume that the (average) speed in Iref has been obtained over the past several frames. The motion speed of the reference part ROIref in the current frame is estimated using, for example, a spline function using the plurality of past time values. The spline function is a function in which derivatives up to the third order are continuous at each sampling point. The moving distance dx can be estimated with higher accuracy by applying the estimated speed of the current frame obtained in this way to the equation (3a).

Returning to FIG. 1, the description will be continued. The ROI setting unit 20 receives the RO from the operator through the control system circuit 6.
In addition to the supply of the I setting signal, the movement amount calculator 19 supplies a movement control signal indicating the two-dimensional movement amount (moving direction and moving distance) of the ROI (region of interest) for each frame. In response to this supply, the ROI setting unit 20 converts the graphic data of the ROI desired to be set on the display image into R
It is generated according to the OI setting signal and its position on the screen is adjusted according to the movement control signal. The graphic data of the adjusted ROI is sent to the data synthesizer 21.

The data synthesizer 21 can display the graphic data of the ROI sent from the ROI generator 20 and the measurement data (graphic data) sent from the biological measuring instrument 18 at each designated position on the screen. To the appropriate frame data.

On the other hand, the display system circuit 5 includes a frame synthesizer 31.
And a display unit 32. Frame synthesizer 31
Synthesizes, on a pixel-by-pixel basis, a frame of image data supplied from the DSC 16 and a frame of graphic data supplied from the data combiner 21 to form frame image data in which graphic data is superimposed on image data. The image data is sent to the display unit 32, subjected to color processing, converted into analog data, and displayed on a color monitor.

Finally, the configuration of the control system circuit 6 will be described.
The control system circuit 6 includes a CPU (controller) 41 as a center of control / processing of the entire apparatus, a console 42 for providing information required by an inspector, and a time phase detector 43.
The CPU 41 interacts with the console 42,
In addition to necessary control such as delay control related to transmission / reception, it has a function of controlling the movement of the ROI by executing the processes illustrated in FIGS. 4 to 6, for example. Here, the console 42 includes a keyboard KY, a mouse MU, an adjustment knob NB, a memory start button MR, a reproduction start button DS, and a measurement start button MS. The keyboard KY and the mouse MU are mainly used for inputting the shape and size of the ROI, the time phase range of interest, the type of biometric information, and the like. Adjustment knob N
B has a function of giving a display frame rate adjustment signal to the CPU 41. The memory start button MR is used to instruct the image memory unit 17 to write image data.
The reproduction start button DS is provided for instructing display of the image data stored in the image memory unit 17 on the monitor of the display unit 32, and the measurement start button MS is provided on the biological measuring device 18 for instructing the start of biological measurement. ing.

The time phase detector 43 comprises, for example, an ECG for detecting electrocardiographic information, and is provided for detecting a cardiac phase. This detector 43 may be a heart sound detector.

Description of Operation When the ultrasonic diagnostic apparatus is used for normal ultrasonic imaging, the operator instructs the operation mode of "scan / display mode" from the keyboard KY of the console 42, for example. In response to this command, the CPU 41 sends a control signal to the changeover switch 15 to turn on its contact a-a ',
Other contacts are switched off. as a result,
Mode processing circuit 1 for B, CFM, TDI, and PWD
1 to 14 are electrically connected to the DSC 16 and the image memory unit 17 is disconnected.

Based on the delay time control from the CPU 41, the transmission system circuit 2 drives the probe 1 to execute, for example, an electronic sector scan using an ultrasonic beam. The echo signal from the inside of the subject obtained by this scanning is again passed through the probe 1 and converted into a signal of the electric quantity.
To enter. The echo signal is sent to the processing circuits 11 to 14 of each mode after the reception signal is focused on the reception system circuit 3 by the delay time control from the CPU 41.

With the configuration and function of each processing circuit described above, the B-mode processing circuit 11 generates B-mode tomographic image data of the ultrasonic scattering intensity with the configuration and function described above. The CFM mode processing circuit 12 generates two-dimensional distribution image data of the blood flow in the scan section, and the TDI mode processing circuit 13 generates two-dimensional distribution image data of the tissue in the scan section. The PWD mode processing circuit 14 outputs Doppler spectral data.

These image data are supplied to the DSC 16. The examiner converts the observed image into the DSC1 via the CPU 41.
6 has been ordered. With this, the DSC 16 changes the scanning method from the ultrasonic method to the standard TV method,
A frame image is synthesized along with the observation image. This image is displayed on the monitor of the display unit 32. As a result, B
An image in which a blood flow distribution image is superimposed on a mode tomographic image, an image of a tissue distribution image alone, and the like are obtained.

Next, the "data storage mode" and the "measurement mode" for operating the ultrasonic diagnostic apparatus as an image diagnostic apparatus will be described. The CPU 41 sequentially executes a series of processes described in FIGS.

First, the CPU 41 sends a control signal to the changeover switch 15 to turn on only the contacts bb 'of the switch 15 and turn off the other contacts (step S1 in FIG. 4). As a result, the processing circuits 11 to 14 and the image memory unit 17 are connected, and the circuit on the DSC 16 side is disconnected. Next, the CPU 41 reads the operation signal from the keyboard KY or the like, determines the type of the measurement target image, the measurement item, and the like, and notifies the image memory unit 17 of the information (step S2). The image memory unit 17 can change the type of the image to be temporarily stored in the processing described below according to the type of the notified measurement target image.

In the present embodiment, the “reference region” is defined as a region on the tissue such as the myocardium. Therefore, in a data storage process described later, when the image to be measured is a tissue image, the TDI mode processing circuit 13 sends the motion information of the tissue. The data and the B-mode tomographic image are stored from the B-mode processing circuit 11. When the measurement target image is a B-mode tomographic image or a blood flow image,
In order to detect the movement speed of the “designated site on the tissue” as the “reference site”, image data of a B-mode tomographic image and / or a blood flow image from the B-mode processing circuit 11 and / or the CFM mode processing circuit 12 is obtained. At the same time,
The movement information data of the tissue is also stored from the DI mode processing circuit 13.

Next, the CPU 41 reads the signal of the memory start button MR (step S3), and waits while judging whether or not storage of the image data in the image memory unit 17 is instructed (step S4). When the storage command of the image data can be determined, the CPU 4
1 instructs the transmission system circuit 2, the reception system circuit 3, and each of the mode processing circuits 11 to 14 to perform an ultrasonic scan of a tomographic plane of a desired diagnostic site (step S5), and furthermore, an image of image data for a predetermined time. The storage in the memory unit 17 is instructed (step S6 in the figure). There are various modes for storing the image data. One of them is to use a time phase signal detected by the time phase detector 43 for a predetermined time (for example, 1).
There is a method of storing image data of (0 heartbeats) for each frame. As another method, data that has passed a certain time is stored while being updated while constantly updating image data for a certain time while overflowing data, and is stored when a storage stop command is issued to the image memory unit 17. This is a method to adopt the latest data within a certain time.

Further, the CPU 41 sets a reproduction start button DS
(Step S7), and waits while judging whether or not the reproduction is started (step S8). When it is determined that the reproduction is started (YES), the CPU 41 instructs the switch cc 'of the changeover switch 15 to turn on and the other contacts to turn off (step S9). Thereby, the reading side of the image memory unit 17 and the DSC 1
6 are connected. Further, the CPU 41 reads the signal of the adjustment knob NB at that time (step S10). This signal is used for adjusting the frame rate when reading image data from the image memory unit 17. That is, by adjusting the adjustment knob NB, the examiner can instruct a reproduction state such as slow reproduction, frame-by-frame reproduction, and stillness.

When the playback preparation is completed, the CPU 41
Commands the image memory unit 17 and the DSC 16 to perform loop reproduction display (step S11). The image data for a certain time stored in the image memory unit 17 is read out to the frame memory 16a of the DSC 16 at the adjusted frame rate and displayed on the monitor of the display unit 32. Since this display is a loop playback, for example, when the last frame of the tenth heartbeat is displayed, 1 is displayed again.
Return to the first frame of the heartbeat. As an example, FIG.
As shown in the figure, the B-mode tomographic image is, for example, 1
It is displayed endlessly for a certain period of time until the 0th heartbeat.

The examiner next enters the setting of the time phase range of interest (POI) while looking at the monitor screen of the loop reproduction display. The time-of-interest range is set to narrow the information collection range of the biological measurement to a time region (frame range) of diagnostic interest. For this reason, among the image data of all the frames stored in the image memory unit 17, a frame phase of an arbitrary time range is usually specified. Specifically, C
While reading the operation signal from the keyboard KY, the PU 41 determines whether or not the setting signal of the time phase range of interest has been input (Steps S12 and S13). When the setting signal is input (YES), the CPU 41 instructs the image memory unit 17 to set a time phase range of interest for the image data (step S14). By this time phase range of interest, image data of a specific frame range of t = a1 to am shown in FIGS. 7A and 7B is narrowed down. The time phase range of interest is usually set based on the diagnostic purpose, such as "systole of a certain heartbeat".

After the setting of the time phase range of interest is completed,
Setting of a measurement ROI (region of interest): ROImea that defines a measurement region of biological information, and a reference ROI: ROIref (reference site) for knowing a movement amount used as a parameter for movement control of the ROI: ROImea to go into.

More specifically, the CPU 41 controls the keyboard K
Y and the like are read, and it is determined whether or not the ROI setting command is issued (steps S15 and S15 in FIG. 5).
16). When an ROI setting command is issued, the shape of the measurement and reference ROIs based on the operation signal,
An ROI setting signal indicating the size is sent to ROI generator 20 (step S17).

Specifically, the ROI generator 20 generates, for example, rectangular ROI graphic data specified by the ROI setting signal at its initial position. This ROI data is sent to the display unit 32 via the data synthesizer 21 and the frame synthesizer 31, and is superimposed on the B-mode tomographic image of the current arbitrary frame (first frame) displayed on the monitor. That is, ROIs for measurement and reference: ROIref, RI on the image of an arbitrary frame in the time phase range of interest.
OImea is initialized.

In the ROI setting process of step S17, the examiner further moves the position of the ROI from the automatically displayed initial position to the desired position. Operator ROI
When the operation to move the position of is performed from the mouse MU or the like,
The contents of this operation are transmitted from the CPU 41 to the ROI generator 20, and the two ROs superimposed on the current frame image are displayed.
I can be moved to respective desired positions.

It is not always necessary to separately set the measurement ROI: ROImea and the reference ROI: ROIref. In the case of blood flow measurement, it is desirable to set the measurement ROI: ROImea on the blood flow and to set the reference ROI: ROIref on the tissue. However, in the case of tissue measurement or luminance measurement, both are set on the tissue. In addition, the positions can be matched to be combined in the same ROI (FIGS. 2, 3, and 7).
reference).

When the setting of the ROI is completed, the CPU 41 reads the signal of the reproduction start button DS (step S1).
8) Based on the read signal, it is determined whether or not the reproduction has started (step S19). In the case of starting reproduction, the CPU 41
Reads the adjustment signal of the adjustment knob NB at that time again,
The instructed frame rate is stored (step S
20). Next, it is determined whether or not the currently displayed frame is the first frame for which the ROI is set (step S).
21). When the ROI has just been set and the update from the first frame in which the ROI has been set has not yet been made (YES), the loop reproduction display based on the adjusted frame rate is performed by the image memory unit 17 and the DSC.
16 (step S22). This gives R
Endless loop reproduction display is started from the frame (first frame) in which the OI is set. If the first frame determined as YES in step S21 corresponds to the first frame immediately after the manual ROI position correction described later, the display command in step S22 is skipped.

After this display start command, the CPU 41 reads the signal of the measurement start button MS and determines whether or not the start of the biological measurement has been commanded (steps S23 and S2 in FIG. 6).
4). If measurement start has not been instructed (NO), an operation signal from the keyboard KY or the like is read to determine whether or not the inspector wants to manually correct the ROI position (step S25).

In the present embodiment, the measurement R
The position of the OI is automatically made to follow the reference site (ROI for reference). However, if for some reason the position of the measurement ROI deviates significantly from the expected following course, or if you want to correct the desired position of the ROI halfway,
You can take advantage of this manual modification.

If the determination in step S25 is YES (manual correction), the CPU 41 temporarily stops the loop reproduction display (step S26), and corrects the positions of the measurement and reference ROIs (step S27).
Also in this process, the CPU 41 reads the operation signal from the mouse MU, reads the correction position, and reads it to the ROI generator 20.
It is implemented by telling. After the manual correction, a restart of the loop playback display is instructed based on the operation signal from the playback start button DS (step S2).
8). After that, the processing of the CPU 41 returns to step S20.
Is returned to.

Therefore, when the display of the first frame in which the ROI is set to the desired position by the inspector in the loop reproduction display is completed, the processing of the CPU 41 proceeds to step 29 through steps 20 and 21. Here, it waits until the timing of the next frame according to the adjusted frame rate. When the timing of the second frame display comes,
YES is determined in the step 29, and then it is determined whether or not the display of the second frame is performed (step S30).

In the case of displaying the frame next to the first frame, that is, the display of the second frame, the determination in step S30 is Y
Since it becomes ES, the automatic tracking processes according to steps S31 to S33 are sequentially executed.

First, the movement amount calculator 19 is instructed to read the speed of the part of the reference ROI: ROIref (step S31). In response to this command, the movement amount calculator 19
From the tissue distribution images of a plurality of frames stored in the image memory unit 17, the image data of the tissue velocity distribution image of the frame at the same time as the second frame is designated, and the reference in the image data is specified. ROI for RO:
The image data of the area corresponding to the part of Iref, that is, the speed data is read.

Next, calculation and storage of the movement amount of the reference ROI are instructed to the movement amount calculator 19 (step S3).
2). Thus, the calculator 19 calculates, for example, the average speed of the portion of the reference ROI: ROIref based on the read speed data, and uses the calculated value as the reference portion (tissue portion).
And the moving amount between the two frames from the previous (first) frame to the current (second) frame of the reference ROI: ROIref is calculated based on this speed. This movement amount is calculated by, for example, the method of FIG. 2 described above.

Next, automatic movement control of the measurement and reference ROIs is performed by the movement amount calculator 19 and the ROI generator 2.
0 (step S33). Therefore, the movement amount calculator 19 sends the calculated movement amount to the ROI generator 20. ROI generator 20 is a measurement ROI: ROImea and a reference ROI whose position is corrected by an amount corresponding to the amount of movement.
I: Generates graphic data of ROIref and sends it to the data synthesizer 21. Thereby, the measurement ROI superimposed on, for example, a tomographic image on the monitor of the display unit 32:
ROImea and ROI for reference as reference site: ROI
The two-dimensional position of ref itself is automatically corrected in the second (next) frame.

When the determination in step S30 is NO, the third and subsequent frames counted from the "first frame" are displayed. In this case, step S3
Step 1 is skipped and the process directly proceeds to step S32. In the case of the frame display of the third frame transition, since the speed of the portion of the reference ROI: ROIref at the time of the previous frame display is stored, this speed is read out and the movement amount is determined by using the method described with reference to FIG. The calculation is performed (step S32).
Then, based on this movement amount, the ROI for measurement and the reference
Is automatically commanded for each frame (step S3).
3).

As a result, the set measurement ROI and reference ROI automatically follow the movement of the tissue while the frame in the time phase range of interest is loop-reproduced at the desired frame rate.

After the processing in step S33, the determination is made as to whether or not to perform the biological measurement in steps S23 and S24 described above. For this reason, unless the examiner operates the measurement start button MS, the image data of the frame in the time phase range of interest is reproduced in an endless loop. During this time, the inspector can visually check whether the measurement ROI automatically follows the desired position while observing the reproduced image, and can manually correct the position as needed (step S25).
To S28). At this time, the reference ROI can also be manually corrected. Further, during this visual observation, the frame rate of the loop reproduction can be arbitrarily adjusted (step S20).

When it is confirmed that the measurement ROI automatically follows the desired position in this way, the inspector operates the measurement start button MS to notify the start of measurement. Accordingly, the process of the CPU 41 exits from step S24 and shifts to step S34. In step 34, the CPU
From 41, a predetermined living body measurement execution is instructed to the living body measuring device 18. In response to the command, the biometric device 18 reads the image data (for example, tomographic image data) of the frame in the time phase range of interest from the image memory unit 17, and the moving amount data of the measuring ROI: ROIref from the moving amount calculator 19. Read. Then, image data of a portion of the movement-controlled measurement ROI: ROIref is specified for each frame, and a desired living body measurement item (for example, luminance change data used for a time density curve) for the portion is specified for each frame (that is, in time series). Is calculated.

When this calculation is completed, the CPU 41 instructs the biological measuring device 18 to display the measurement result (step S3).
5). As a result, the data of the measurement results is
1 to the frame combiner 31 and the display unit 32. As a result, for example, if the measurement item is luminance information and the time phase range of interest is one heartbeat, a luminance change curve (TDC) within the one heartbeat is obtained, and the result is displayed on a B-mode tomographic image, for example. It is displayed on a monitor as a superimposed image, and is provided to an examiner and a doctor.

The above-described biological measurement processing can be repeatedly performed as necessary (see step S36). Therefore, re-measurement can be performed from the image data storage, and another item of living body measurement can be performed using the image data once taken into the image memory unit 17.

A specific R for measurement related to the above series of processing
FIG. 7 shows an example of OI tracking.

Now, the image to be measured is a B-mode tomographic image,
It is assumed that the measurement item is scattering intensity (luminance) measurement. In this case, two types of image data of a B-mode tomographic image and a two-dimensional distribution image of a tissue are fetched into the image memory unit 17 for a plurality of frames for a predetermined time. Assuming that the time phase of this fixed time is n heartbeats of t = 11 to t = nn, a B-mode tomographic image of the n heartbeats is reproduced in a loop as shown in FIG.

While looking at this reproduced image, the time phase range of interest by the examiner is, for example, the time phase t of the “systole of a certain heartbeat”.
= A1 to am. Next, measurement and reference ROIs are set on a specific frame in the time phase range of interest. In this case, since the measurement item is luminance information, the measurement ROI: ROImea and the reference ROI: ROI
ref can be substituted with one ROI. This is because the measurement site is on the tissue, and a site on the tissue can be adopted as the reference site.

Thereafter, while the frame image of the time phase range of interest is loop-reproduced, the ROI (= ROI)
The amount of movement of the region of interest is estimated as the meaning of ref, and the ROI (= ROImea) as the measurement site is estimated using the estimated amount.
Is controlled as shown in FIG. 7B. For example, luminance change data is measured based on the ROI position data obtained by the tracking control.

For example, when the scan site is the heart, the left ventricle performs a contraction-expansion motion, and the tissue moves toward the contraction center as shown in FIG. For this reason, in the conventional case, the measurement ROI set in one frame moves relative to the subject in another frame, and it is difficult to measure a living body at a desired position or the measurement accuracy is significantly reduced. Although invited, such inconvenience can be avoided by the above-described configuration and processing. In most cases, the examiner simply sets the ROI for measurement and / or reference on a specific display frame, and in most cases, the ROI for measurement automatically follows a desired part. In addition, the following state can be confirmed on the monitor screen, and if there is a defect in the ROI setting for any reason, it can be manually corrected or changed. Therefore, since the measurement ROI is always placed at the position intended by the examiner for all frames within the time phase range of interest, the accuracy of the biological measurement performed thereafter is significantly improved as compared with the conventional measurement. As a result, the reliability of the measurement data is greatly improved.

Even when manual correction is required,
Since there is no need to modify every frame as in the past,
The amount of operation by the inspector (observer) is drastically reduced. The operation is simplified, the time required for the image diagnosis itself is shortened, and this contributes to an improvement in the throughput of the image diagnosis. The requirement for operational proficiency is also relaxed, since manual modification is virtually unnecessary.

Further, it is not necessary to widely set the ROI in advance in anticipation of the displacement of the measurement ROI as in the related art. Since the ROI can be set only for a specific site that is truly of diagnostic interest, the reliability and accuracy of the measurement result can also be improved.

Further, in the case of the present apparatus, the examiner has a system configuration in which image collection and living body measurement are performed separately, so that the examiner can concentrate on each work.

(Other Embodiments) Other embodiments according to the present invention will be described.

In the embodiment described above, the number of measurement ROIs is one. However, a plurality of measurement ROIs can be set. For example, as shown in FIG. 8, two measurement ROIs: ROImea1 and ROImea2 may be set (each ROI is common to the reference ROI: ROIref1 (ROIref2)). FIGS. 4 to 4 described above regarding the plurality of measurement ROIs.
By applying the processing of FIG. 6, it is possible to perform the biological measurement of the items given from each of the measurement ROIs. Further, another characteristic amount (for example, a luminance ratio, a luminance difference, an input / output ratio of blood flow) can be simultaneously calculated from each measurement result of the plurality of measurement ROIs.

In each of the above-described embodiments, a method is adopted in which one ROI is used for both the measurement ROI and the reference ROI (reference part). However, this may be set separately for each ROI. This form is necessary especially for blood flow measurement. This example is shown in FIGS.

Now, in the case of blood flow measurement in the left ventricular outflow tract of the heart, it is assumed that the measurement item is a velocity profile in the outflow tract. As shown in FIG. 9, on the image in which the blood flow distribution image is superimposed on the B-mode tomographic image, an elongated measurement ROI: ROImea whose velocity profile is to be measured is set in the left ventricular outflow tract. At the same time, in order to make the ROI: ROImea follow the movement of the surrounding myocardial tissue, another reference ROI: ROIref for analysis of the surrounding movement speed is set in the aortic valve annulus, for example, as shown.

The estimation of the amount of movement when these two ROIs are set is performed as follows based on, for example, the geometric relationship shown in FIG. To simplify the calculation, it is assumed that the measurement ROI moves in the direction of the ultrasonic scanning line. Assuming that the tissue movement speed is v as in the above-described embodiment, the Doppler speed vd
Is vd = v · cos θ. Assuming that the moving speed of the measurement ROI is v ′, v ′ = v · cos α (α is an angle between the speeds v and v ′). Therefore, the moving distance dx of the measurement ROI is obtained by dx = v ′ · dT (dT is the inter-frame time). By moving the measurement ROI for each frame using this movement amount (the movement distance is dx and the movement direction is the scanning line direction), the measurement ROI is changed so that the relative positional relationship with the surrounding tissue does not change. Automatic tracking is possible. This series of follow-up control can be realized by the same processing as in FIGS. 4 to 6 described above.

As a result, since the position of the measurement ROI always covers the left ventricular outflow tract, the velocity profile can be measured reliably and accurately. Using this measurement value, for example, Japanese Patent No. 1926682 The stroke volume can be calculated as shown.

Further, the following modification is possible in setting the time phase range of interest. In the above-described embodiment, the configuration has been described in which the time phase range of interest is manually specified while viewing the loop playback image. For this,
Using the detection signal of the time phase detector 43 as it is, for example, C
The PU 41 may automatically determine the systole and the diastole, and may automatically specify the time phase range. This allows
The examiner need only specify the ROI for measurement and reference, and the operation is further simplified. At this time, for example, it is displayed together with an electrocardiographic waveform so that the examiner can recognize which time phase has been automatically set. This notation is:
A method of indicating the set time phase range with the markers of the start point and the end point or a method of highlighting the entire set time phase range with colors or patterns can be adopted to increase the recognition degree. The processing required for these displays may be executed by, for example, the CPU 41 and the ROI generator 20 in FIG.

In the above-described device configuration, the changeover switch 15 is not provided, and the processing circuits 11 to 14, the DSC 1
6, and the CPU 41 controls the reading and writing between the three of the image memory unit 17 so as to control the exchange of data in three directions.

[0095]

As described above, the medical image diagnostic apparatus according to the present invention 1) calculates the amount of movement of the position of the region of interest for each frame based on the motion information of the reference region on the ultrasonic image, Using this movement amount, R for biometric measurement for each frame
A configuration for controlling the position of the OI, and 2) storing time-series image data for a plurality of frames obtained by scanning a cross section inside the object with an ultrasonic signal, and arbitrarily selecting the image data for the plurality of frames. The image data of the frame is displayed on a monitor to obtain motion information of a reference portion on the display image, a region of interest (ROI) for biometric measurement is set on the image, and the plurality of regions are determined based on the motion information of the reference portion. The ROI position is controlled by calculating the movement amount of the position of the region of interest with respect to the image data of the remaining frames for the frame, and the biological information based on the image data in the region of interest is measured based on the image data for the plurality of frames. Is the main part. Thereby, the position of the ROI for living body measurement can always be made to accurately follow the initially intended portion without being affected by the movement of the tissue. Therefore, compared to the conventional ROI setting, the relatively simple tracking control enables highly accurate and reliable biometric measurement, significantly reduces the operation labor, improves the operation efficiency, and improves the operation efficiency. It is possible to provide a medical image diagnostic apparatus in which the restriction on the skill level is relaxed.

[Brief description of the drawings]

FIG. 1 is a block diagram of an ultrasonic diagnostic apparatus functionally equipped with an image diagnostic apparatus according to one embodiment of the present invention.

FIG. 2 is a schematic diagram showing one method of estimating the movement amount of a reference part.

FIG. 3 is a schematic diagram illustrating an example of angle correction when estimating a movement amount of a reference part.

FIG. 4 is a flowchart showing an automatic ROI tracking process along with FIGS. 5 and 6;

FIG. 5 is a flowchart showing an automatic ROI tracking process along with FIGS. 4 and 6;

FIG. 6 is a flowchart showing an automatic ROI tracking process together with FIGS. 4 and 5;

FIG. 7 is a diagram schematically showing a process of an automatic ROI tracking process.

FIG. 8 is a diagram showing an example of setting of a plurality of measurement ROIs.

FIG. 9 shows a measurement ROI and a reference ROI for blood flow measurement.
The figure which shows an example of the setting of.

FIG. 10 is a view for explaining a geometric relationship between two ROIs shown in FIG. 9;

[Explanation of symbols]

REFERENCE SIGNS LIST 1 ultrasonic probe 2 transmission system circuit 3 reception system circuit 4 processing / operation system circuit 5 display system circuit (display means) 6 control system circuit 11 to 12 processing circuit 13 processing circuit (motion information acquisition means) 15 changeover switch (storage means) / Display means / motion information acquisition means) 16 DSC (display means) 17 image memory unit (storage means) 18 biometric device (measurement means) 19 travel distance calculator (travel distance calculation means) 20 ROI generator (ROI setting means) / Position control means /
CPU (storage means / display means / exercise information acquisition means / ROI setting means / movement amount calculation means / position control means / measurement means / data designation means / manual adjustment means) 42 console (ROI setting means / data) Designation method /
Manual adjustment means)

Claims (13)

[Claims] 1. Based on time-series image data of a plurality of frames obtained by scanning a cross section inside an object with an ultrasonic signal, biological information of an ROI (region of interest) set on an image based on the image data is obtained. A medical image diagnostic apparatus for measuring, wherein: a motion information acquisition unit for obtaining motion information of a reference portion on the image; and the ROI for each frame based on the motion information.
And a position control means for controlling the position of the ROI for each frame using the movement amount calculated by the movement amount calculation means. Medical diagnostic imaging device. 2. A storage means for storing a plurality of frames of time-series image data obtained by scanning a cross section in a subject with an ultrasonic signal, and an image of an arbitrary frame among the plurality of frames of image data. Display means for displaying data on a monitor; exercise information acquisition means for acquiring exercise information of a reference site on an image displayed on the monitor; and ROI setting for setting an ROI (region of interest) for biometric measurement on the image Means, movement amount calculating means for calculating the movement amount of the position of the ROI with respect to the image data of the remaining frames for the plurality of frames based on the movement information of the reference region, and movement amount calculated by the movement amount calculation means A position control means for controlling the position of the ROI on the display image of the image data of the remaining frame using the image data of the remaining frame, and an image in the ROI based on the image data of the plurality of frames. A medical image diagnostic apparatus comprising: a measuring unit that measures biological information based on image data. 3. The ultrasonic diagnostic apparatus according to claim 3, wherein said storage means, said display means, said movement information obtaining means, said ROI setting means, said movement amount calculating means, said position control means, and said measuring means are integrally mounted. The medical image diagnostic apparatus according to claim 2. 4. The medical image diagnostic apparatus according to claim 1, wherein a position of the ROI for measuring a living body and a position of the reference part are identical. 5. The medical image diagnostic apparatus according to claim 4, wherein the ROI for living body measurement and the reference site are both commonly located in a part of a tissue such as a myocardium. 6. The medical image diagnostic apparatus according to claim 1, further comprising a reference part designating unit that designates a position of the reference part independently of a position of the biological measurement ROI. 7. The medical image diagnostic apparatus according to claim 6, wherein the reference site is a part of a tissue such as a myocardium of the subject, and a position of the ROI for measuring a living body is located at a blood flow site. 8. The medical image diagnostic apparatus according to claim 1, further comprising a data designating unit that designates image data of a frame in a time phase range of interest among the image data of the plurality of frames. 9. The moving amount calculating means for estimating the moving amount from image data of two temporally adjacent frames of the remaining frames of the plurality of frames. 4. The medical image diagnostic apparatus according to claim 1. 10. The moving amount calculating unit according to claim 1, wherein the moving amount estimating unit calculates the moving amount by using a function as a medium from image data of a plurality of frames in the remaining frames of the plurality of frames. Medical diagnostic imaging device. 11. The moving amount calculating unit according to claim 1, further comprising a correcting unit configured to correct the image data in accordance with an angle difference between a direction of the ultrasonic signal and a direction of movement of the reference part. Medical diagnostic imaging device. 12. The medical image diagnostic apparatus according to claim 1, further comprising a manual adjustment unit capable of manually adjusting a position of the ROI controlled by the position control unit. 13. The medical image diagnostic apparatus according to claim 2, wherein the number of the ROIs set by the ROI setting means is plural.