JPH0924047A - Ultrasonic diagnostic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ultrasonic diagnostic device capable of saving an image effective for contrast medium inspection and diagnosis without any deficiency using a limited frame memory. SOLUTION: In an ultrasonic diagnostic device, an ultrasonic contrast medium is injected into a specimen, and the cross section of the specimen is scanned with an ultrasonic beam for repeatedly generating an image according to the first period, on the basis of an available ultrasonic echo signal. This ultrasonic diagnostic device is equipped with a TIC operation part 13 for finding a time- brightness curve regarding space within the interest zone of an image, and means 12 and 17 for selectively saving an image on the basis of the curve.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic diagnostic apparatus having various image processing functions for the purpose of detecting blood flow perfusion and quantitatively evaluating the perfusion using an ultrasonic contrast agent. .

[0002]

2. Description of the Related Art There are various medical applications of ultrasonic waves, the mainstream of which is an ultrasonic diagnostic apparatus for obtaining a tomographic image of a soft tissue of a living body using an ultrasonic pulse reflection method. This ultrasonic diagnostic apparatus is a non-invasive examination method and displays a tomographic image of a tissue. The X-ray diagnostic apparatus, X-ray CT apparatus, MR
Compared to other diagnostic devices such as I and nuclear medicine diagnostic devices,
It has the features that real-time display is possible, the device is small and inexpensive, there is no exposure to X-rays, etc., and safety is high, and blood flow imaging is possible by the ultrasonic Doppler method. Therefore, ultrasonic diagnosis is widely performed in the heart, abdomen, mammary gland, urology, obstetrics and gynecology. In particular, you can get real-time display of heart beats and fetal movements by simply applying an ultrasonic probe from the body surface, and because it is highly safe, you can repeat tests and move to the bedside. It is convenient because it can be easily tested.

In such an ultrasonic diagnostic apparatus, the blood flow dynamics are being evaluated by injecting an ultrasonic contrast agent from a vein in the examination of the heart and abdominal organs, for example. Since the injection of the contrast medium from the vein is less invasive, the diagnosis by the evaluation method of the hemodynamics is becoming popular. In many contrast agents, microbubbles serve as a reflection source, and if the injection amount / concentration is high, the contrast effect will be large, but due to the nature of the bubbles, the ultrasonic effect shortens the contrast effect time. In recent years, long-lasting and pressure-resistant contrast agents have been developed, but it is expected that their long-term persistence in the body will increase their invasiveness.

The earliest diagnosis using a contrast agent is to know the presence or absence of blood flow at the diagnosis site by examining the presence or absence of brightness enhancement by the contrast agent. Further advanced diagnoses include those that use the state of the temporal distribution of the spatial distribution of the contrast agent at the diagnosis site and the spatial spread of the contrast agent as the material. Further, in recent years, a time intensity curve (TIC; Time Intensity Curve) for the ROI
Based on the above, a dynamic study using the time from the injection of the contrast agent until it reaches the region of interest (ROI), the outflow time, the maximum brightness, etc. is also made. Then, conventionally, the change in the echo level of the ultrasonic echo caused by the contrast agent is detected simply by visually recognizing the change in the brightness level of the B-mode image, or by storing a plurality of image data in the device and then observing each image. Was used to quantitatively measure echo level changes and create TICs using a histogram calculation function.

[0005]

When an ultrasonic contrast agent is administered and a diagnosis is made based on the degree of shadowing in a region of interest, it is important to acquire an image collected at the maximum shadowing time.
For this image, for example, it is possible to obtain quantitative information on the degree of shadowing by comparing it with the image brightness before injection. The conventional ultrasonic diagnostic apparatus is equipped with an image memory capable of displaying measured frame images retroactively in the past and an image memory capable of storing an image at an arbitrary time as a snapshot by a manual operation of a console switch. Has been done. The former is a few seconds (tens of ~
The current situation is that only a few hundred frames can be stored. The measurement in administration of a contrast agent may require observation for about 1 to 3 minutes, and a memory of 10 times or more as compared with the conventional one is required to effectively store the peak of the stain. In the latter case, for example, it is necessary to visually grasp the moment of the brightness peak and perform the manual operation, and there is a risk of missing that moment.

Further, even when the TIC of the region of interest is to be measured, storing an image for several minutes as a digital image requires a huge memory,
Not realistic. Currently, VTR (Video Tape Recorde)
r), etc., once stored in an external storage device, and then these measurements are performed using an analysis device.
In addition to the deterioration of the image quality, the problem arises that it takes the same or longer time to review the measurement image again in order to obtain the TIC above all.

The present invention has been made in view of the above circumstances, and an object thereof is to make it possible to efficiently use a limited frame memory and to store an image useful for a contrast agent inspection diagnosis without a shortage. A sound diagnostic apparatus is provided.

[0008]

According to the present invention, an ultrasonic contrast agent is injected into a subject, a cross section of the subject is scanned with an ultrasonic beam, and an image is displayed based on the obtained ultrasonic echo signal. In an ultrasonic diagnostic apparatus that repeatedly generates in one cycle,
The image forming apparatus further comprises means for obtaining a time-intensity curve regarding the region of interest of the image, and means for selectively storing the image based on the time-intensity curve.

The image repeatedly generated in the first cycle is selectively stored based on the time intensity curve. Therefore, it becomes possible to efficiently use the limited storage capacity and store images useful for the contrast agent examination diagnosis without any shortage.
This means that re-examination is not required because images useful for diagnostics of contrast agent diagnosis are not stored, and the effect of avoiding the invasive problem of reinjecting the contrast agent into the subject is spread. Can be acquired.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. The present invention is applicable to all regions of interest when a blood flow state is observed by administering a contrast agent and the degree of contrast (contrast degree), but here, the degree of blood flow is known from the degree of contrast to the liver parenchyma, Description will be made assuming a case of identifying an abnormal portion. The blood flow state in the heart using the ultrasonic diagnostic apparatus can be viewed in the thick blood vessels of each organ by color display. However, normally, the blood flow of a relatively thin blood vessel to the myocardium and the parenchyma of the liver cannot be observed or the received echo signal is minute and cannot be captured. When contrast echo (enhanced reflected wave) from the blood flow of myocardium is used as a reception signal using an ultrasonic contrast agent, blood flow is identified in a B-mode image in the heart chamber and blood vessel, and the liver is also identified. Substantial blood flow can be observed. A time-brightness curve (hereinafter simply referred to as TIC; Time Intensity Curve) is obtained by measuring the time-dependent change in the brightness level in the above-mentioned region.

FIG. 1 is a block diagram of an ultrasonic diagnostic apparatus according to this embodiment. The ultrasonic diagnostic apparatus according to this embodiment includes an electrocardiograph (ECG) 1, an ultrasonic probe 4, an apparatus main body 22, and an operation panel (console) 3. On the operation panel 3, a mouse 16a for inputting a region of interest (ROI), a trackball 16b, and one of a plurality of modes in which conditions of an image to be stored in a TIC frame memory 12 described later are different is selected. It is equipped with a mode selection switch 16c, a keyboard 16d for inputting detailed conditions of the selected mode, and the like. The electrocardiographic waveform signal measured by the electrocardiograph 1 is sent to the memory synthesizing unit 9 as necessary via the amplifier 2 and the reference data memory 3.
It is displayed on the display unit 10 together with the B-mode image and the TIC.

The ultrasonic probe 4 has a piezoelectric vibrator as an acoustic / electric reversible conversion element such as a piezoelectric ceramic. A plurality of piezoelectric vibrators are arranged in parallel and mounted on the tip of the ultrasonic probe 4. The apparatus main body 22 is configured as follows with the CPU 17 as a control center of the entire system. An ultrasonic wave transmitter 4 and an ultrasonic wave receiver 5 are connected to the ultrasonic probe 4. The ultrasonic transmitter 6 includes a pulse generator 6A,
It has a transmission delay circuit 6B and a pulser 6C. The pulse generator 6A has a rate frequency fr (cycle; 1
/ Fr) repeatedly generates the rate pulse. This rate pulse is distributed to the number of channels, and the transmission delay circuit 6B
Sent to The transmission delay circuit 6B focuses each ultrasonic wave into a beam and gives each rate pulse a delay time necessary for determining the transmission direction. In the transmission delay circuit 6B, the trigger from the trigger signal generator 19 is supplied to the timing signal generator 18
Is supplied as a timing signal. Pulsar 6C
Applies a voltage pulse to the probe 1 for each channel at the timing when the rate pulse is received from the transmission delay circuit 6B. As a result, ultrasonic waves are transmitted in a beam shape in the direction according to the delay time.

The reflected wave reflected by the discontinuity surface of the acoustic impedance in the subject is received by the ultrasonic wave receiving section 5 via the ultrasonic wave probe 4. The ultrasonic receiver 5 is a preamplifier 5
A, a reception delay circuit 5B, and an adder 5C. The received signal is amplified by the preamplifier 5A for each channel, given a delay time necessary for determining the receiving direction by the reception delay circuit 5B, and added by the adder 5C. As a result, an echo signal in which a specific direction component is emphasized is obtained.

The ultrasonic wave transmitting section 6 and the ultrasonic wave receiving section 5 scan one frame while changing the delay time once or every predetermined number of transmissions and receptions. Also, the ultrasonic transmitter 6
Then, the ultrasonic receiving unit 5 repeats the scanning of one frame with a certain period (first period) over time.

The echo signal output from the adder 5C is
It is sent to the receiver unit 7. Although not shown, the receiver section 7 is composed of an envelope detection circuit, a logarithmic amplifier, and an analog-digital converter (A / D). The envelope detection circuit detects the envelope of the echo signal to obtain a detection signal that reflects the reflection intensity. The logarithmic amplifier logarithmically amplifies the detection signal. The output signal of the logarithmic amplifier is digitized through an analog-digital converter.

The original data of the B-mode image output from the receiver unit 7 is sent to the display unit 10 via the B-mode digital scan converter (DSC) unit 8 and the memory synthesizing unit 9 and is visually displayed as a real-time B-mode image. Is displayed in gray.

The B-mode image data output from the B-mode digital scan converter 8 is sent to the frame memory 11 and the TIC calculator 13. The frame memory 11 has a capacity capable of storing image data for several seconds, for example, and operates under the control of the CPU 17 so as to always store the latest image data for several seconds endlessly.

The TIC calculation unit 13 integrates the brightness values of a plurality of pixels existing in the ROI using the B-mode image data output from the receiver unit 7, and associates the brightness level of the ROI with the scan time information. Ask for. The scan time is defined as the time to start transmission / reception along the first raster of one frame, for example. The brightness level data and the time data are sent to the display unit 10 via the B-mode digital scan converter unit 8 and the memory synthesizing unit 9, and B
It is combined with the mode image into one frame and displayed visually as TIC.

The brightness level data and time data from the TIC calculator 13 are also supplied to the CPU 17. CPU17
Is based on the brightness level data and the time data, that is, based on TIC, so that one frame of B-mode image data repeatedly obtained in the first cycle is selectively stored in the TIC frame memory 12, Frame memory 11
And the writing operation of the TIC frame memory 12 are controlled.

Next, the operation of this embodiment will be described. The cross section of the subject is repeatedly scanned by the ultrasonic beam at a constant period (first period) by delay control by the ultrasonic wave transmitting unit 6 and the ultrasonic wave receiving unit 5. The receiver section 7 and the B-mode digital scan converter section 8 repeatedly generate B-mode image data for one frame in the first cycle. The B-mode image data is sent to the display unit 10 via the memory synthesizing unit 9 and visually displayed in real time as a B-mode image of a moving image.

The operator operates the mouse 16a or the trackball 16b to set a region of interest (ROI) on the B-mode image as shown in FIG. By operating the mode selection switch 16c by the operator, C
Reading of the frame memory 11 by the PU 17 and TIC
A mode relating to the control of the writing operation of the frame memory 12 is set. Here, the first to fourth modes are presented. The operation of each mode will be described later. The selection condition of the stored image, which means the selected mode, is displayed on the display unit 10 together with the B-mode image as full-text character information or simply as an index so that the operator can understand.

B-mode image data for one frame is repeatedly supplied to the TIC calculation unit 13 from the receiver unit 7 in the first cycle. The luminance values of a plurality of pixels existing in one frame of ROI are integrated as the luminance level of ROI.
This brightness level data is associated with scan time information, is interpolated as needed, is sent to the display unit 10 via the B-mode digital scan converter unit 8 and the memory synthesizing unit 9, and is sent together with the B-mode image. It is combined into a frame and visually displayed as a TIC as shown in FIG.

If the calculation of the ROI for each frame is performed, it is considered that a minute fluctuation as shown in FIG. 4A occurs due to a change in the speckle pattern accompanying the minute movement of the ultrasonic probe 4. To be Therefore, it is preferable that the TIC calculation unit 13 obtains an average value of a plurality of frames and performs a smoothing process as shown in FIG. Further, when observing a relatively slow change in luminance, frames for which TIC calculation is performed may be thinned out and processed. In this case, the operator can set the sample interval (thinning width), the average processing time, the display interval, etc. from the operation panel 16.

An example of the averaging process will be described with reference to FIG.
In this example, four luminance levels (x _n ) measured as shown in FIG. 5A are used to obtain an average value, which is taken as the luminance level (y _n ) at that time, and the following measured value (x _n ) If one is shifted by one and the average value is calculated, each average value can be calculated at the same time interval as the measured value. The average number can be set arbitrarily, and the smoothing effect is improved when the number is increased. Further, the number of shifts may be arbitrary, and in this case, the average value is equivalent to the thinning processing of the measured values. By performing such averaging processing, FIG.
As shown in (b), it is possible to prevent erroneous extraction of the peak (maximum brightness) of the brightness level caused by an instantaneous change.

The brightness level data and the time data obtained by the TIC calculator 13 are sent to the CPU 17. CPU
17 is based on the brightness level data and the time data,
That is, based on the temporal brightness change, the frame memory 11 is read and read so that one frame of B-mode image data repeatedly obtained in the first cycle is selectively stored in the TIC frame memory 12 according to the mode. It controls the write operation of the TIC frame memory 12. Each mode will be described below. The relationship between TIC and brightness is shown in FIG. 6 for reference. The contrast intensity of the contrast agent is remarkably stronger than the reflection intensity between other tissues. Therefore, B
On the mode image, the phenomenon occurs as high brightness. (First Mode) FIG. 7 shows the CPU in the first mode.
17 is a time chart showing a B-mode image stored in the TIC frame memory 12 under the control of 17. B-mode image data I1, I2, I3, ... For one frame is repeatedly generated in the first cycle P1. T0 indicates the scan start time, and T1 indicates the time when the brightness level becomes maximum. Under the first mode, the image I9 having the maximum brightness level is stored in the TIC frame memory 12. Further, before time T1, the images I1, I3, ... Are periodically stored in the TIC frame memory 12 in the second period P2 longer than the first period P1, and before the time T1, before the time T1.
The images I1, I3, ... Are periodically stored in the TIC frame memory 12 in the third period P3, which is longer than the second period P2. The second period P2 and the third period P3 are P1
Within the limit range of <P2 <P3, the operator can freely set through the operation panel 16. TI in Figure 4
As can be seen from C, the slope of the brightness change is relatively large during the contrast agent inflow period (before the maximum brightness), and the slope of the brightness change is relatively small during the contrast agent outflow period (after the maximum brightness). This means that in the contrast agent inflow period, it is necessary to record an image at a relatively short cycle in order to perform image diagnosis with high accuracy in observing the spread of the contrast agent over time. In the outflow period, it means that even if an image is recorded in a relatively long cycle, the accuracy of image diagnosis is allowed.
Therefore, it is possible to efficiently use the limited TIC frame memory 12 to store an image useful for a contrast agent examination diagnosis without any shortage. This means that re-examination is not required because images useful for diagnostics of contrast agent diagnosis are not stored, and the effect of avoiding the invasive problem of reinjecting the contrast agent into the subject is spread. Can be acquired. (Second Mode) FIG. 8 shows the CPU in the second mode.
17 is a time chart showing a B-mode image stored in the TIC frame memory 12 under the control of 17. Under the second mode, the image I9 having the maximum brightness level is displayed.
Are stored in the TIC frame memory 12. Further, as shown in FIG. 9, after the time T1 (contrast agent outflow period), the image I12 in which the brightness level is −3 dB at the maximum, that is, the brightness level is reduced to half the maximum value is displayed in the frame memory for TIC. Stored in 12. Therefore, there is a limited TIC
It is possible to efficiently use the use frame memory 12 to store an image useful for a contrast agent inspection diagnosis without any shortage.
This means that re-examination is not required because images useful for diagnostics of contrast agent examination are not stored, and the effect of avoiding the invasive problem of injecting the contrast agent into the subject again is spread. Can be acquired. (Third Mode) FIG. 10 shows the CP in the third mode.
It is a time chart which showed the B mode picture memorized by frame memory 12 for TIC by control of U17. Third
In this mode, the image I9 with the maximum brightness level is displayed.
Are stored in the TIC frame memory 12. In addition, after time T1 (contrast agent outflow period), the image I13 when the first time IV1 has elapsed from the time T1 and the time T1
The image I17 when the second time IV2 has elapsed from 1 is stored in the TIC frame memory 12. Therefore, it is possible to efficiently use the limited TIC frame memory 12 to store an image useful for the contrast agent examination diagnosis without any shortage. The first time IV1 and the second time IV2 can be freely set by the operator via the operation panel 16. This means that re-examination is not required because images useful for diagnostics of contrast agent examination are not stored, and the effect of avoiding the invasive problem of injecting the contrast agent into the subject again is spread. Can be acquired. (Fourth Mode) FIG. 11 shows the CP in the fourth mode.
It is a time chart which showed the B mode picture memorized by frame memory 12 for TIC by control of U17. 4th
Under this mode, the images I6 to I12 obtained within the period P before and after the time T1 are stored in the TIC frame memory 12. The images I6 to I12 include, of course, the image I9 having the maximum brightness level. Therefore, there is a limited TIC
It is possible to efficiently use the use frame memory 12 to store an image useful for a contrast agent inspection diagnosis without any shortage.
This means that re-examination is not required because images useful for diagnostics of contrast agent examination are not stored, and the effect of avoiding the invasive problem of injecting the contrast agent into the subject again is spread. Can be acquired. The period P can be freely set by the operator via the operation panel 16. Also, the period P before the time T1 in the period P
The period P2 after the time T1 may be individually set by the operator via the operation panel 16.

The ROI may be set at two or more places. In this case, the brightness level calculation, the averaging process, and the like are performed in parallel by the TIC calculation unit 13, and when the maximum value of the brightness for each ROI is detected, the brightness level is fetched into the image memory at any time. Also, multiple TICs are calculated,
It can be displayed on the display screen if necessary.

Next, an example of TIC display is shown in FIG. The measurement result is displayed in real time on one of the divided screens. When a plurality of ROIs are designated, they may be displayed in an overlapping manner as shown in FIG. 12, or a plurality of graphs may be displayed. Furthermore, as shown in FIG.
It is possible to store the brightness level inside the ROI obtained by the calculation unit 13 in the memory 21 and display the results collectively after the end of scanning. Since the scale level before the averaging process is stored, it is possible to calculate and display the averaging process many times by changing the parameters after the scan is completed.

FIG. 13 is a display example of the extracted and stored frame image. Also in this case, as in the case of FIG. 12, it is possible to display on one of the divided screens. this is,
It may be displayed immediately at the time of extraction, or may be displayed by calling from the TIC frame memory 12 after measurement. When there are a plurality of extracted images, it is possible to switch the frame images using a dial or buttons on the operation panel. Also, the screen may be divided into four or more parts to display a plurality of images.

Further, a label is added to a part of the displayed image so that the content of the extracted image can be understood. In the example of FIG. 7, the image at the maximum brightness is extracted, and “MA
"X" is displayed. When an image having a brightness of -3 dB from the maximum brightness is extracted, the required time from the maximum brightness time may be displayed. Note that management of these time information is performed by an instruction from the CPU 17 of FIG. 1 to the TIC calculation unit 13. The present invention is not limited to the above-described embodiments, but can be modified in various ways.

[0030]

According to the present invention, an ultrasonic contrast agent is injected into a subject, a cross section of the subject is scanned with an ultrasonic beam, and an image is generated in a first cycle based on the obtained ultrasonic echo signal. An ultrasonic diagnostic apparatus that is repeatedly generated includes means for obtaining a time-intensity curve for the region of interest of the image, and means for selectively storing the image based on the time-intensity curve.

The image repeatedly generated in the first cycle is selectively stored based on the time intensity curve. Therefore, it becomes possible to efficiently use the limited storage capacity and store images useful for the contrast agent examination diagnosis without any shortage.
This means that re-examination is not required because images useful for diagnostics of contrast agent diagnosis are not stored, and the effect of avoiding the invasive problem of reinjecting the contrast agent into the subject is spread. Can be acquired.

[Brief description of drawings]

FIG. 1 is a block diagram of an ultrasonic diagnostic apparatus according to a preferred embodiment of the present invention.

FIG. 2 ROI set on the displayed B-mode image
FIG.

FIG. 3 is a diagram showing an example of a TIC.

FIG. 4 is an explanatory diagram of an effect of averaging processing.

FIG. 5 is an explanatory diagram of averaging processing.

FIG. 6 is a diagram showing a relationship between TIC and brightness.

FIG. 7 is an operation explanatory diagram of a first mode.

FIG. 8 is an operation explanatory diagram of a second mode.

FIG. 9 is a supplementary explanatory diagram of the operation in the second mode.

FIG. 10 is an operation explanatory diagram of a third mode.

FIG. 11 is an operation explanatory diagram of a fourth mode.

FIG. 12 is a diagram showing an example of a display screen.

FIG. 13 is a diagram showing another example of a display screen.

FIG. 14 is a block diagram of a main part of a modified embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Electrocardiograph, 2 ... Amplifier, 3 ... Reference data memory, 4 ... Ultrasonic probe, 5 ... Ultrasonic receiving part, 5A ... Preamplifier, 5B ... Reception delay circuit, 5C ... Adder, 6 ... Ultrasonic transmitting part , 6A ... Pulse generator, 6B ... Transmission delay circuit, 6C ... Pulser, 7 ... Receiver section, 8 ... B-mode DSC section, 9 ... Memory combining section, 10 ... Display section, 11 ... Frame memory, 12 ... TIC frame Memory, 13 ... TIC calculation part, 16 ... Operation panel, 16a ... Mouse, 16b ... Trackball, 16c ... Mode selection switch, 17 ... CPU, 18 ... Timing signal generator, 19 ... Trigger signal generator.

Claims (10)

[Claims] 1. An ultra-sound system that injects an ultrasonic contrast agent into a subject, scans a cross section of the subject with an ultrasonic beam, and repeatedly generates an image in a first cycle based on the obtained ultrasonic echo signal. An ultrasonic diagnostic apparatus comprising: a unit that obtains a temporal brightness curve for the region of interest of the image; and a unit that selectively stores the image based on the temporal brightness curve. 2. The ultrasonic diagnostic apparatus according to claim 1, wherein the storage unit stores an image having the maximum brightness in the region of interest based on the temporal brightness curve. 3. The ultrasonic diagnostic apparatus according to claim 1, wherein the storage unit stores an image in which the brightness in the region of interest is decreased from the maximum brightness to a predetermined level based on the temporal brightness curve. 4. The storage means stores an image after a predetermined time has elapsed from the time when the brightness in the region of interest shows the maximum brightness based on the temporal brightness curve.
An ultrasonic diagnostic apparatus as described in the above. 5. The storage means stores an image periodically in a second cycle longer than the first cycle before a time when the brightness in the region of interest becomes maximum based on the temporal brightness curve,
The ultrasonic diagnostic apparatus according to claim 1, wherein an image is periodically stored in a third cycle longer than the second cycle after the time when the brightness in the region of interest becomes maximum. 6. The storage means stores the image periodically at a third cycle longer than the first cycle after the time when the brightness in the region of interest becomes maximum based on the temporal brightness curve. The ultrasonic diagnostic apparatus according to claim 1, which is characterized in that. 7. The storage means stores an image generated within a predetermined period before and after the time when the brightness in the region of interest becomes maximum based on the temporal brightness curve. Ultrasonic diagnostic equipment. 8. The ultrasonic diagnostic apparatus according to claim 1, further comprising means for displaying an image to be stored in the storage means side by side with a real-time image. 9. The ultrasonic diagnostic apparatus according to claim 1, further comprising means for displaying together with images the selection conditions of the images to be stored in said storage means in an understandable manner. 10. An ultrasound contrast medium is injected into a subject, a cross section of the subject is scanned with an ultrasound beam, and an image is repeatedly generated in a first cycle based on the obtained ultrasound echo signal. An ultrasonic diagnostic apparatus, comprising: a unit that periodically stores an image in a second cycle that is longer than the first cycle.