JP2011110211A - Medical image display device and distribution image configuration method for hemodynamics - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem in that hemodynamics of an image subject can not be easily recognized. <P>SOLUTION: A medical image display device includes an image data configuration part for configuring image data of a tomographic image surface of the image subject, a time change curve computing part for computing the time change curve from image data, a parameter computing part 14 for computing a parameter providing a characteristic point of the time change curve, and a distribution image configuration part 16 for configuring the distribution image including the time axis information of hemodynamics from the parameter. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a medical image display device and a distribution image construction method for creating a distribution image reflecting blood flow dynamics in an imaging region based on a medical image in a living body.

  The ultrasonic diagnostic apparatus is one of diagnostic apparatuses widely used in the medical field together with MRI (Magnetic Resonance Imaging) and CT (Computed tomography). The ultrasonic diagnostic apparatus has features such as small size, high spatial resolution, and high temporal resolution. Furthermore, in recent years, improvement in diagnostic performance using an ultrasonic diagnostic apparatus is expected due to the development of angiographic techniques and tumor imaging techniques accompanying the spread of contrast agents.

  The blood flow around and inside the tumor shows not only the presence or absence of lesions but also the nature of the tissue, giving important information for differential diagnosis. Until now, X-ray CTA (CT-Angiography) has been mainly used to acquire blood vessel images. In CTA, an iodine contrast agent is intravenously injected, and a plurality of X-ray images acquired at the stage where the contrast agent passes through the blood vessel is reconstructed to visualize the blood vessel structure in three dimensions. However, CTA has the side effects of exposure and contrast agents.

  On the other hand, an image diagnostic method using ultrasonic waves has a feature that does not involve invasion such as exposure during imaging. In addition, since the contrast medium uses microbubbles having a diameter of several μm, the contrast medium itself is not toxic. Furthermore, since the contrast agent is discharged out of the body by a metabolic function that the body naturally has as time passes, there is a feature that the burden on the patient is small. The contrast agent resonates with an ultrasonic wave of several MHz used in the medical field and emits a strong nonlinear signal. For this reason, a fine blood vessel structure can be depicted with high contrast by specifically detecting and imaging a nonlinear signal.

  Contrast agents are roughly classified into high sound pressure type and low sound pressure type due to the difference in behavior with respect to ultrasonic irradiation. The high sound pressure type is used when bubbles are crushed by ultrasonic irradiation with high sound pressure (mechanical index: MI 1.0 to 1.9), and an image is formed by a non-linear signal generated at that time. Since the contrast agent disappears with each irradiation, it is necessary to appropriately change the imaging surface in order to observe the contrast in the same region. On the other hand, the low sound pressure type is used when an image is constructed with a non-linear signal obtained by resonating without causing bubbles to be collapsed by (MI 0.1 to 0.9) ultrasonic irradiation. For this reason, the continuous contrast effect is exhibited by the characteristics of the low sound pressure type contrast agent, and continuous observation of the same region becomes possible.

  Some contrast agents undergo phagocytosis of Kupffer cells present in the sinusoids connecting arteries and portal veins to central veins. Therefore, when ultrasonic irradiation is performed in a state where the contrast medium is filled in the liver tissue, the region where the Kupffer cells are functioning normally is stained with high luminance. By observing this shadow, a lesion area such as a tumor can be identified as a defect in luminance. Furthermore, high brightness and duration of shadowing are one index for evaluating the function of Kupffer cells. For this reason, it is considered to be effective for liver function diagnosis.

  Thus, the contrast image is effective not only for observing a fine blood vessel structure but also for judging the function of the tissue, and has become widespread mainly in the abdominal region. As described above, the low-sound-pressure type contrast agent resonates when irradiated with ultrasonic waves and generates a nonlinear signal. Therefore, the contrast effect is maintained, and the progress of the shadow can be observed on the same imaging surface.

  The staining process varies depending on the tissue. For example, in the case of a normal liver, the arterial, portal vein, and vein blood vessels are stained at different time phases depending on the path, and then the liver tissue is stained. However, when there is a tumor, it exhibits a different staining process depending on the degree of vascular proliferation and activity. For this reason, if the dynamics of the staining are observed in detail, the properties of the tumor can be known from the state of the staining process. Such a difference in the staining process depending on the tissue indicates fluctuations in blood flow such as a blood flow path, flow rate, and velocity starting from the heart, that is, blood flow dynamics.

  An important index for quantifying the difference in the dyeing process is a time-intensity curve (TIC) in which the temporal change in luminance accompanying the inflow of contrast medium is plotted. For example, in the case of a liver tumor, it is important to distinguish whether the tumor blood vessel is formed starting from the artery or the portal vein. However, since the artery runs along the portal vein, the portal vein is not stained. Once started, it is difficult to distinguish between the two with a single contrast image. However, by comparing the TIC of each blood vessel, the difference in the staining process can be evaluated, and the blood vessel that is the origin of the tumor blood vessel can be objectively determined.

  Patent Document 1 relates to a technique for calculating an index value such as a luminance average value from a TIC measured by a transmission sequence in which high and low sound pressures are combined, and presenting an image color-coded according to the calculated value. In the TIC measurement, a high sound pressure ultrasonic irradiation to a tissue filled with a contrast agent is started as a trigger, and the process of the contrast agent recirculating in the imaging surface is measured based on the low sound pressure irradiation.

JP 2005-81073 A

  However, in the above-described conventional technology, in order to compare blood flow dynamics for each region, it is necessary to perform visual observation while replaying a moving image, and lack of objectivity of information, a plurality of regions cannot be observed simultaneously. There are problems such as a heavy burden on the operator. In addition, observation of blood flow dynamics starting from the heart is important for evaluating tissue properties, and the contrast medium that is administered flows along the perfusion of the original blood flow and is stained from the time it reaches the tissue. It is necessary to observe the progress.

  In the present invention, after obtaining a time change curve of an RF signal of image data to be imaged by calculation, a parameter giving a characteristic point of the time change curve is obtained by calculation, and time axis information of blood flow dynamics based on the parameter A technique for constructing a distribution image including

  According to the present invention, a difference in time axis information in blood flow dynamics can be displayed as a distribution image.

1 is a diagram illustrating a configuration example of an ultrasonic diagnostic apparatus (Example 1). FIG. 10 is a diagram for explaining processing steps from administration of a contrast agent to display of a color map image (Example 1). FIG. 6 is a diagram for explaining an example of TIC measurement and an example of smoothing processing (Example 1). The figure which shows an example of a display form (Example 1). The figure which shows the example of a display of a navigation screen (Example 1). FIG. 10 is a diagram illustrating an example of a display form of a color map image (Example 1). (Example 1) which shows the example of a display form at the time of displaying a color map image in parallel. FIG. 6 is a diagram for explaining an example of changing a display range of a color map image (Example 1). FIG. 6 is a diagram for explaining an example of changing a color range (Example 1). FIG. 6 is a diagram for explaining an example of changing a color range (Example 1). FIG. 10 is a diagram illustrating an example of an image in which information outside the color range is superimposed on information within the color range (Example 1). (Example 1) which shows the example of an image which superimposes a background image on a color map image. The figure explaining the process outline | summary for simplifying the waveform of TIC (Example 1). FIG. 1 is a diagram illustrating a configuration example of an ultrasound diagnostic apparatus having a position correction vector calculation unit (Example 1). FIG. 6 is a diagram illustrating a configuration example of an ultrasonic diagnostic apparatus (Example 2). The figure explaining the positional relationship of a different imaging surface (Example 2). (Example 2) which shows the structural example of the three-dimensional color map by the image data of each imaging surface. FIG. 10 is a diagram illustrating a configuration example of an ultrasonic diagnostic apparatus having a position correction vector calculation unit (second embodiment). FIG. 6 is a diagram for explaining a position correction processing operation (first embodiment). The figure explaining the position correction processing operation (Example 2). The figure explaining the measurement operation | movement of TIC using a position correction process (Example 1). FIG. 6 is a diagram for explaining position correction processing by TIC smoothing (Example 1). FIG. 3 is a diagram for explaining a storage trigger for image data (Example 1).

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. It should be noted that the contents of the device configuration and processing operation described below are examples for explaining the invention, and the present invention relates to an invention in which a known technology is combined with the device configuration and processing operation described later, and the device configuration and processing operation described later. It also includes inventions that partially replace known techniques. Hereinafter, an ultrasonic diagnostic apparatus which is one form of the medical image display apparatus will be described.

(A) Example 1
Example 1 of the present invention will be described below. Here, a case where a two-dimensional image (tomographic image) is displayed as a medical image will be described.

(overall structure)
FIG. 1 shows a block configuration example of the ultrasonic diagnostic apparatus according to the first embodiment. 1 includes a probe 2, a transmission beam former 3, a reception beam former 4, an A / D converter 5, a D / A converter 6, a TGC (time gain compensation) 7, an envelope detection. Unit 8, scan converter (SC) 9, image memory 10, TIC calculation control unit 11, TIC calculation unit 12, drawing information input unit 13, parameter calculation unit 14, display information input unit 15, distribution image configuration unit 16, display unit 17.

  The probe 2 is a device that transmits and receives an ultrasonic signal to the imaging target 1. For example, it is composed of a piezoelectric element. The transmission beamformer 3 and the reception beamformer 4 are devices that give a predetermined time delay so that a desired transmission / reception beam is formed on the piezoelectric element constituting the probe 2. The A / D converter 5 and the D / A converter 6 are devices that perform digital conversion or analog conversion on transmission / reception signals. The TGC 7 is a device that corrects amplitude attenuation that occurs in a process in which an ultrasonic signal propagates inside a living body. The envelope detector 8 is a device that detects a received RF signal and converts it into an image signal. SC9 is a device that constructs two-dimensional image data from image signals. The image memory 10 is a device that stores the image data configured by the SC 9 at a predetermined sampling interval. The TIC calculation control unit 11 is a device that executes control operations related to TIC measurement processing, such as setting of sampling intervals of image data and setting of a region of interest for performing TIC measurement. The TIC calculation unit 12 is a device that measures TIC based on the control content set by the TIC calculation control unit 11. The drawing information input unit 13 is a device for designating parameters calculated from the TIC. The parameter calculation unit 14 is a device for calculating a parameter corresponding to the drawing information from the TIC measured by the TIC calculation unit 12. The display information input unit 15 is a device for changing the color map image displayed on the display unit 17 and the display form of the TIC. The distribution image constructing unit 16 is a device for constructing a color map image based on parameters. The display unit 17 is a device for displaying the color map image configured by the distribution image configuration unit 16.

(Processing operation of image data component)
In FIG. 1, a system that executes processing operations from reception of ultrasonic waves by the probe 2 to configuration of image data is called an image data configuration unit, and the corresponding portion is surrounded by a broken line. The image configured by the image data configuration unit is a monochrome image (B mode) or a contrast agent image (an image in which a signal from the contrast agent is emphasized by a transmission / reception sequence, a filter process, etc.) of an ultrasonic diagnostic apparatus that is used for general purposes. The construction method is generally known. Therefore, a brief description will be given below.

  The ultrasonic irradiation surface of the probe 2 has a one-dimensional array configuration in which a plurality of piezoelectric elements are arranged in a line, and each element is responsible for transmitting and receiving ultrasonic waves. A voltage pulse applied from the transmission beam former 3 is input to each piezoelectric element via the D / A converter 6, and ultrasonic waves are irradiated toward the imaging target 1 by piezoelectric vibration of each piezoelectric element. At this time, a predetermined time delay is electronically given to each piezoelectric element, and the ultrasonic wave transmitted from each piezoelectric element is focused at a predetermined position inside the imaging target 1. The ultrasonic wave (reflection echo) reflected by the imaging target 1 is received by each piezoelectric element, and amplitude correction corresponding to the propagation distance is executed by the TGC 7 in order to correct the attenuation of the signal generated in the propagation process. Subsequently, the reception signal is sent to the reception beamformer 4 via the A / D converter 5, and an addition result is output by multiplying a delay time according to the distance from the focal position to each piezoelectric element (phased addition). ).

  As a technique for enhancing and imaging a signal from a contrast agent, for example, a method of transmitting two signals whose phases are reversed and adding the received signals is well known. While the fundamental frequency component mainly contained in the tissue component is suppressed by the addition of the received signal, the harmonic component mainly contained in the signal from the contrast agent is enhanced.

  By performing transmission / reception of ultrasonic waves on all scanning lines along the piezoelectric element array, a two-dimensional reflection echo distribution of the imaging target 1 can be obtained. An RF (Radio Frequency) signal divided into a real part and an imaginary part is output from the reception beamformer 4 and sent to the envelope detection unit 8. The signal sent to the envelope detector 8 is converted into a video signal and then output to the SC 9. The SC9 adds pixel interpolation between the scanning lines of the input video signal, and reconstructs it into two-dimensional image data. The reconstructed image data is displayed on the display unit 17.

(Color map composition operation)
Next, processing steps up to the construction of a color map image reflecting the TIC measurement and blood flow dynamics based on the image data constructed in SC9 will be described with reference to the flowchart shown in FIG.

(Process 0)
First, the operator confirms image data displayed on the display unit 17 while operating the probe 2 by a general usage method, and determines an imaging surface in a region of interest. In this state, a contrast medium is administered. The administration of the contrast agent is executed according to an instruction from an operator or the like.

(Process 1)
Thereafter, the image data of the imaging surface is stored in the image memory 10 at an appropriate timing. The start and end of storage are executed through operator input to the TIC switch installed on the operation panel of the ultrasonic diagnostic equipment. The image data storage start trigger is output to the TIC calculation unit 12 and the SC 9. When the save start trigger is input, the SC 9 starts saving an image to the image memory 10.

  Here, if a TIC switch is provided in the probe 2, the operability of the operator can be further improved. Also, the function that compares the acquired image data with the image data acquired immediately before it and automatically starts saving the image data from when the luminance change becomes large (that is, the function that automatically generates the save start trigger) ) Can be further improved in operability.

  For example, the following processing functions are installed. First, the difference between the data values of the acquired image and the image acquired immediately before is calculated for each pixel, and the sum of them is calculated. Next, it is determined whether or not the calculated sum continues to increase over, for example, 0.5 seconds (corresponding to 10 frames at a frame rate of 20), and image data is automatically saved from the time of detection of the corresponding event. To start.

  In general, it takes several seconds from the start of inflow of the contrast agent to the increase in brightness. Further, the time difference until the contrast medium flows into the artery, portal vein, and other blood vessels also requires 1 second or more from the start of the flow of the contrast medium. For this reason, as described above, even if the image data is acquired from the time point 0.5 seconds after the start of the inflow, the image data reflecting the blood flow dynamics of each blood vessel can be acquired.

  However, as shown in FIG. 23, the acquired image data is automatically saved, and the number of seconds set in advance from the input point of the save start trigger based on the manual operation of the operator or based on the automatic function described above. By adopting a system that retains image data after the time point that is traced back (from 1 second to several seconds) and discards the previous image data, the image data before the start of the inflow of the contrast agent can also be saved.

  In this embodiment, the operator sets the sampling interval of the image data stored in the image memory 10 in the TIC arithmetic control unit 11 in advance. In order to measure TIC with high accuracy, it is preferable to save all image data configured by SC9. However, when the storage capacity of the mounted or mountable image memory 10 is limited, it is necessary to set the sampling interval in consideration of the frame rate for acquiring the image data and reduce the load on the image memory 10. The increase in luminance on the image data due to the inflow of the contrast agent reaches an equilibrium state in a few seconds. For this reason, sampling of at least about 4 Hz is necessary. For example, when the frame rate is 20 Hz, image data is stored at a rate of at least every 5 frames.

(Process 2)
Next, the TIC calculation unit 12 uses a single pixel (x, y) (x = 1... X _max , y = 1) constituting the image data (image size (x _max * y _max )) stored in the image memory 10. Focusing on y _max ), as shown in FIG. 3, the luminance values f (f1 (x, y), f2 (x, y) of the pixels at the same position from all the acquired time-series image data fn (X, y)) is measured. When the horizontal axis is set to time, the vertical axis is set to the luminance value, and the measured luminance value is plotted, a luminance change curve (TIC) corresponding to each pixel (x, y) is obtained as shown in the middle part of FIG. .

  Here, for TIC, the brightness change from before ultrasound contrast is important. Therefore, the difference value between the luminance value fi (x, y) (where i is a natural number) and the initial value f1 (x, y) at each time point is calculated, and “0” is set as the starting point of the difference value. However, since the information of the initial value f1 (x, y) is retained, the operator can restore and confirm the original TIC from the difference value fi (x, y) as necessary. The TIC measurement may be executed in units of pixels of the image data stored in the image memory 10 or may be executed in units of a preset pixel range.

  In addition, when using a preset pixel range as a unit, the average luminance value of the corresponding region may be used for TIC. Further, the TIC measurement range (that is, the image configuration range) may be limited to the range of the region of interest set on the image data by the operator. The region of interest may be set in advance on the image data displayed on the display unit 17 before starting the storage of the image data. The image displayed on the display unit 17 after the storage of the image data is finished. It may be set on the data. When the region of interest is set before starting the storage of the image data, the image data itself stored in the image memory 10 can be limited to the range of the region of interest. The load can be reduced. Information on the region of interest that limits the TIC measurement range is input to the TIC calculation control unit 11.

Next, the TIC calculation unit 12 executes a smoothing process on the measured TIC. The lower part of FIG. 3 shows an image of the smoothing process. The smoothing process is an averaging process in the time axis direction of the TIC, and the luminance undulation caused by the pixel position shift and noise is reduced. In this embodiment, in order to maintain the measured number of sampling points of the TIC, the luminance value I _ti for each time ti (i = 1, 2,...) Of the TIC is calculated as shown below. For example, when obtaining the luminance value I _ti as five points average, the luminance value of each time after the smoothing _{processing, I t1 = (I t1 +} I t2 + I t3 + I t4 + I t5) / 5, I t2 = (I t2 + I _t3 + I _t4 + I _t5 + I _t6 ) / 5... Note that the TIC measurement process in step 2 is executed simultaneously with the saving of the image data, except when a region of interest is set for the image data saved in the image memory 10.

  By the way, at the time of TIC measurement by the TIC calculation unit 12, if the patient's body movement or the operator's hand shake is large, the position of the imaging target may be shifted in the image data, and a TIC measurement error may occur. In order to correct this misalignment, it is desirable to install a position correction vector calculation unit in the ultrasonic diagnostic apparatus. FIG. 14 shows a configuration example of an ultrasonic diagnostic apparatus including the position correction vector calculation unit 18. In FIG. 14, the same reference numerals are given to the corresponding parts to FIG. 1, and the apparatus configuration is the same as that of the ultrasonic diagnostic apparatus shown in FIG. 1 except for the position correction vector calculation unit 18.

  The position correction vector calculation unit 18 executes position correction processing at a stage prior to measurement processing by the TIC calculation unit 12 as necessary. A generally known pattern matching process is applied to the position correction process. First, the position correction vector calculation unit 18 sets a reference region that is a reference for position correction on the acquired first image data. Next, the position correction vector calculation unit 18 sets a search area on the image data to be position corrected. The center position of the search area is the same as that of the reference area, and the size of the search area is arbitrarily set by the operator according to the size of the positional deviation to be corrected.

  FIG. 19 shows a correction operation image by the position correction vector calculation unit 18. As shown in FIG. 19, the position correction vector calculation unit 18 searches the search area for a matching area that can be regarded as the same as the reference area, and uses a vector connecting the center position of the matching area and the center position of the search area as a position correction vector. measure. As a method for searching for a matching region, for example, a method is used in which the sum of absolute difference values is calculated while shifting the reference region pixel by pixel within the search region, and the region having the minimum value is used. As a search index, in addition to the sum of absolute differences described above, there are a least square sum, a correlation value by cross-correlation calculation, and the like.

Thereafter, when reading the luminance value from each stored image data, the TIC calculation unit 12 adjusts the pixel position to be read according to the measured position correction vector. As a result, it is possible to realize TIC measurement that suppresses the influence of the positional deviation of the imaging target. FIG. 21 shows an image of the position correction function. 21 shows an image in the case where there is no position correction function in the upper part of FIG. 21, and shows an image in the case where there is a position correction function in the middle part of FIG. In the figure, f _t0 is reference image data, and f _t1 , f _t2 , f _t3 , f _t4 , and f _t5 are images to be subjected to position correction. The observation target 211, the TIC measurement position 212, and the position coordinates of the observation target 211 on each image data are shown.

When position correction is not performed (upper stage in the figure), the measurement position 212 of the TIC is fixed regardless of the position change of the observation target 211 due to the position shift. This can also be confirmed from the fact that the pixel position used for TIC measurement shown in the lower part of the figure is the same pixel (x ₀ , y ₀ ) at all time points t. In this case, since the observation target 211 and the measurement position 212 of the TIC do not match, an error occurs when measuring the luminance value. On the other hand, when position correction is performed (middle in the figure), the TIC measurement position 212 also moves following the change in position of the observation target 211. This can also be confirmed from the fact that the pixel position used for the TIC measurement shown in the lower part of the figure changes with time t. In this case, since the observation target 211 and the TIC measurement position 212 coincide with each other, accurate TIC measurement is possible.

In addition to this, there is also a method of correcting the influence of misalignment by selecting the luminance approaching smoothing from the adjacent TIC, assuming that the TIC undulation is caused by misalignment. Specific processing contents will be described below with reference to FIG. FIG. 22 shows the change in luminance from time t ₀ to time t ₈ of the pixel (x ₀ , y ₀ ) to be corrected and the two pixels (x ₁ , y ₁ ) and (x ₂ , y ₂ ) adjacent thereto. Each is indicated by a circle mark, a triangle mark, and a square mark.

In FIG. 22, the TIC before correcting the positional deviation is indicated by a broken line. For Figure 22, TIC has a large relief from time t ₃ toward t _8. On the other hand, the TIC after correcting the positional deviation, each pixel intensity value at time t _1, corresponding to the time _{t 1 (x 0, y 0} ), (x 1, y 1), (x 2, y 2 The value closest to the average value of the luminance values at time t ₀ and time t ₂ is selectively used. Similarly, the luminance value at time t _2, each pixel corresponding to the time _{t 2 (x 0, y 0} ), (x 1, y 1), the time t ₁ of the luminance values of (x _2, y ₂₎ The value closest to the average value of the luminance values at time t ₃ is selectively used. This process is repeated, and the TIC relief of the pixel of interest is corrected with the brightness value of the surrounding pixels and smoothed. Thereby, the TIC shown by the solid line in FIG. 22 is measured. As shown, the relief is removed.

  In this embodiment, an example in which correction processing is performed on two adjacent pixels has been described. However, the number of pixels referred to at the time of correction is not limited, and for example, correction processing is performed using all eight adjacent pixels. May be executed. However, there is a trade-off relationship between the correction accuracy and the processing load, and it is desirable to determine the number of pixels used for correction in consideration of the processing time.

(Process 3)
In step 3, the process of constructing a color map indicating blood flow dynamics is started. This step 3 is started when the operator activates the drawing information input unit 13 by an operation input to a predetermined switch on the operation panel or the display screen. Simultaneously with the activation of the drawing information input unit 13, the image data stored in the image memory 10 is reproduced on the display unit 17 as a moving image in time series. The reproduced image to be displayed may be an image displayed on the display unit 17 from the SC 9 and stored by compressing the data.

  When the region of interest is set on the reproduced contrast image, the TICs of the region of interest ROI are displayed side by side on the display screen 41 as shown in FIG. A plurality of regions of interest ROI can be installed at arbitrary positions. When multiple TICs are displayed on the screen, TIC parallel display and superimposed display can be freely selected. Also, the operator can freely edit the display form, such as displaying only the region of interest ROI or TIC specified by the operator in a superimposed manner and displaying other TICs in parallel. The display example of FIG. 4 shows an example in which two TICs corresponding to two regions of interest ROI are displayed in a superimposed manner, and the TICs corresponding to the other four regions of interest ROI are displayed in parallel.

(Process 4)
In step 4, the operator selects and inputs drawing information using the displayed TIC. The drawing information selection input is executed based on a navigation screen 51 as shown in FIG. FIG. 5 shows an example of the navigation screen. On the navigation screen 51, an appropriate TIC (a schematic diagram of TIC or any TIC constituting the display screen 41) and representative drawing information are displayed. On the screen of the navigation screen 51, an identification code attached to each drawing information is provided so that the operator can easily understand the relationship between each drawing information and the physical quantity (value, range, etc.) of the TIC. Lines and shading with numbers (in the case of FIG. 5) are displayed in duplicate in the TIC display area.

  In the case of FIG. 5, drawing information (1) to (9) described below is displayed for selection input by the operator. The drawing information (1) is the inflow start time. The inflow start time indicates the time at which the contrast medium administered from the vein flows into the region of interest ROI and starts staining. The drawing information (2) is the equilibrium luminance arrival time. The equilibrium brightness arrival time indicates the time when the contrast medium is sufficiently circulated and the brightness value reaches the equilibrium state. The drawing information (3) is the disappearance start time. The disappearance start time indicates the time when the contrast agent disappears from the equilibrium state and the TIC starts to decrease. The drawing information (4) is the duration. The duration indicates the time from when the brightness reached by the TIC reaches the threshold, until the threshold is interrupted by the disappearance of the contrast agent, in other words, the length of time that the TIC exceeds the threshold. The drawing information (5) is a threshold luminance arrival time. The threshold luminance arrival time indicates the time to reach the threshold luminance. Drawing information (6) is the TIC increase rate. The rate of increase in TIC is an index that reflects the blood flow rate, and is given by the rate of time change of TIC from the start of staining to equilibrium. The drawing information (7) is the TIC descent rate. The TIC descent rate is an index that reflects the rate of disappearance of the contrast agent, and is given by the time change rate of the TIC when the TIC descends from the equilibrium state. The drawing information (8) is the equilibrium luminance. The equilibrium brightness is an index value that reflects the blood flow, and is a brightness value when the contrast agent is sufficiently circulated to reach an equilibrium state. The drawing information (9) is an integral value. The integral value is an index that suggests the total flow rate during the measurement of TIC, and is the time integral value of TIC (shaded area in FIG. 5).

  The operator operates the pointer displayed on the display unit 17 to select a desired number on the screen, thereby operating and inputting drawing information. The drawing information input unit 13 highlights the drawing information selectively inputted by the operation and the corresponding TIC number on the screen, so that the operator can easily identify the selection item. In the case of FIG. 5, an underline is used for highlighting. As other highlighting, the corresponding characters are bolded or colored.

  Note that the display order of the drawing information on the navigation screen 51 can be ranked based on the frequency selected by the operator in the past, the importance of image diagnosis (for example, tumor diagnosis), and the like. It can be changed freely. In addition, the threshold necessary for calculating the threshold luminance arrival time and duration is set from the screen by moving the arrow (arrow (5) or (4) in FIG. 5) installed on the TIC, for example. be able to. In this embodiment, the luminance value at the designated position is displayed on the screen when the threshold value is set. By displaying the luminance value as a numerical value, it is possible to set a threshold value independent of the sense.

  Of course, the drawing information that constitutes the navigation screen 51 is an example. In addition to adding or deleting items, changing the displayed text, drawing information that can be measured based on the TIC is newly defined. Can be edited freely.

(Process 5)
In this step, the parameter calculation unit 14 calculates a parameter corresponding to the drawing information selected through the operation input in step 4. For parameter calculation, a function having typical TIC characteristics is specified, and the measured TIC is simplified to the specified function form. FIG. 13 shows a calculation image by the parameter calculation unit 14. Fig. 13 shows the measured TIC (dashed line) and the TIC (solid line) simplified by a specified function. The defining function starts at a luminance value of 0, increases linearly at the first time point, reaches an equilibrium luminance value at the second time point, and then reaches a constant time equilibrium state and then linearly at the third time point. It is assumed to descend. That is, a function that approximates the shape of the TIC with a combination of line segments is assumed.

First, the parameter calculation unit 14 calculates an inclination indicating a luminance increase from the first time point to the second time point. At this time, the parameter calculation unit 14 calculates, based on the TIC, an average luminance value I _avg obtained by averaging the luminance values corresponding to the entire range of the measurement period over time and ½ of the average luminance value (that is, I _avg / 2). The time t _upavg , t _{upavg / 2} , t _downavg , t _{downavg / 2 at} which the TIC gives each luminance value is calculated. Here, the time t _up means the time during which TIC rises, and the time t _down means the time during which TIC falls.

When each time is obtained, the parameter calculation unit 14 calculates the slope of the luminance change (luminance change per unit time). The slope of the period in which the brightness rises is the rate of increase in TIC, and the slope of the period in which the brightness falls is the rate of decrease in TIC. Here, the rate of increase of TIC is calculated as (I _avg −I _{avg / 2} ) / (t _upavg −t _{upavg / 2} ), and the rate of decrease of TIC is (I _avg −I _{avg / 2} ) / (t _downavg -t _{downavg / 2} ).

  Next, the parameter calculation unit 14 obtains the calculated slope (increase rate) and a straight line (function) passing through the two points used for the calculation, and calculates the time point when the luminance value becomes “0”. The parameter calculation unit 14 sets the calculated time point as the first time point. This time corresponds to the inflow start time.

Then, the parameter calculating unit 14 has established between the time t _Downavg time t _Upavg the falling period of the rising period, which provides a mean brightness value I _avg in the calculation range, a luminance average value of the measured TIC for the calculation range Calculate again. The parameter calculation unit 14 sets the luminance average value as a luminance value (equilibrium luminance value) that gives an equilibrium state of TIC.

  When the equilibrium luminance value is calculated, the parameter calculation unit 14 sets the time point when the straight line passing through the two measurement points used for calculation of the slope in the TIC rising period reaches the equilibrium luminance value as the second time point, and the TIC falling period. The point in time when the straight line passing through the two measurement points used for calculation of the slope reaches the equilibrium luminance value is defined as the third point in time.

In the calculation process described above, if the luminance value of the TIC in the falling period does not reach I _{avg / 2} , it is assumed that the equilibrium state continues from the second time point, and the time at the third time point is set as the measurement end time, the luminance value. Is the equilibrium luminance value. By the above calculation, the parameter calculation unit 14 can automatically calculate the inflow start time, the equilibrium luminance arrival time, the disappearance start time, the TIC increase rate, the TIC decrease rate, and the equilibrium luminance.

  Incidentally, if the operator inputs a threshold value, the duration time, the threshold luminance arrival time, and the integral value can be directly calculated from the measured TIC without applying the simplification process as described above. For this reason, the simplification process as described above is not necessarily required for the duration, the threshold luminance arrival time, and the integral value. However, if a threshold value is applied to the function indicating the characteristics of the TIC as described above, changes in the drawing information can be immediately reflected in the color map.

  The parameter calculation unit 14 stores the calculated parameters in the image memory 10. However, if all the parameters calculated for each pixel are stored in the image memory 10, the capacity load of the image memory 10 increases. Therefore, in order to reduce the load on the image memory 10, the information stored in each pixel constituting the image data is set to the initial value of the TIC calculated by the TIC simplification process, the first time point, the second time point, and the third time point. , You may limit to the TIC descent rate. With these five pieces of information, the TIC outline of each pixel can be reproduced and a color map image can be constructed.

In the above description, the change in TIC is approximated by a line segment, but it can also be approximated using an arbitrary function as shown below. For example, a generally known fitting process is defined by defining a function y = A (1−e− ^βt ) where A is the equilibrium luminance after the first time point, t is the time, and β is the rate of change in luminance due to the inflow of the contrast agent. Thus, A and β giving the characteristics of TIC may be calculated by calculation. Also, if the contrast agent inflow start time is introduced as a parameter t ₀ , the function y = A (1−e− ^{β (t + t} 0 ⁾ ) is set, and if 0 <t <t ₀ , y = A, then the contrast agent flows. It is also possible to perform fitting processing on data from the previous stage.

(Step 6)
In this step, a color map image is formed that is color-coded according to the size of each parameter value calculated in the previous step. The color map image is created by the distribution image construction unit 16 and displayed on the screen of the display unit 17. FIG. 6 shows a display form example of the display screen 41 including a color map image. The display screen 41 shown in FIG. 6 is based on the display part of the contrast image corresponding to the stored image data, the display part of the TIC corresponding to the selected region of interest ROI, the display part of the drawing information, and the drawing information selected by the operator. And a display unit for a color map image created in this way.

  In the drawing information display unit, one or a plurality of drawing information selected by the operator is highlighted so as to be distinguishable from other drawing information. FIG. 6 is an example in which the inflow start time is selected, and the corresponding characters are displayed so as to be surrounded by a bold line. In addition, an arrow indicating a position corresponding to the drawing information selected by the operator or a corresponding physical quantity is displayed on the display unit of the TIC. In the case of FIG. 6, an arrow indicating the inflow start time is shown. In the case of FIG. 6, since there are two regions of interest ROI selected in the contrast image, two corresponding TICs are displayed in duplicate. Further, the TIC in FIG. 6 corresponds to the average value of the TIC for the pixels existing in the region of interest ROI.

  The display unit of the color map image displays each pixel constituting the contrast image with a color corresponding to the parameter value calculated for the drawing information selected by the operator. A set of the color-coded pixels is a color map image. FIG. 6 is an example of a color map image showing the difference in inflow start time by color coding. A color bar is additionally displayed at a position near the color map image. The color bar exemplarily shows the relationship between the parameter and the color. The example in FIG. 6 indicates that the darker the color, the faster the inflow start time. Note that the correspondence between the parameters and the colors can be freely changed by the operator. For example, the correspondence between the color gradation, the size of the parameters, and the color shading can be changed. The color bar can display not only qualitative information such as “slow” and “fast” but also quantitative information such as numerical values of actually calculated parameters.

  The position of the region of interest and the drawing information can be freely changed on the screen by the operator using a pointer or the like. When a plurality of drawing information is selected by the operator, color map images corresponding to the respective drawing information are displayed in parallel on the display screen 41 as shown in FIG. By displaying a plurality of color map images in parallel in the same display screen 41, it becomes easy to compare the difference in blood flow and inflow start time.

  For example, in the case of a liver tumor, the blood vessel that is the origin of the tumor blood vessel and the blood flow volume of the tumor tissue are important information for diagnosis, but color map images with drawing information such as inflow start time, equilibrium luminance, or integral value are displayed in parallel. Thus, for example, it is possible to evaluate the distribution and density of blood vessels and tumor tissues that have been grown from an artery as a starting point.

  The information displayed on the display screen 41 can be freely combined by the operator from among TIC, drawing information, contrast image, color map image, etc. The arrangement of the display unit corresponding to each information and the size of the display unit are as follows. The operator can freely edit.

(Change of color map image display)
Next, a method for changing the display form of the color map image will be described. The change in the display form of the color map image may be performed based on the color bar, when performed based on the TIC, or based on the color map image. It should be noted that by adjusting the use range of the parameters used for displaying the color map image, for example, by appropriately narrowing, it is possible to emphasize and display a region showing similar blood flow dynamics.

  First, the case of changing the display form based on the color bar will be described with reference to FIG. FIG. 9 is a display example of a color map image for the threshold luminance arrival time. In this case, two arrows displayed near the color bar are operated to change the display form. By specifying two arrows, it is possible to specify a limited color region, that is, a parameter range, on the color map image. Color optimization can be performed by correcting the arrow position.

  For example, if the display range is limited to 5 to 15 seconds for the color map image with the threshold luminance arrival time, color redistribution can be realized within the limited range. At the same time, the limited area is displayed on the TIC display section so that the limited area can be identified by the operator. In FIG. 9, a limited range of 5 to 15 seconds is displayed by shading.

  Next, a case where the display form is changed based on the TIC will be described. In this case, it can be realized by adjusting the shaded range on the TIC described above with the pointer, that is, by adjusting the evaluation time and the luminance range. In the case of this modification, the display of the color map image changes following the adjustment of the shaded range. In addition, the following functions can be realized by changing the display format based on TIC. Usually, an accurate parameter cannot be calculated in a region where the contrast agent does not recirculate. For this reason, these area portions may be displayed as noise on the color map image. Therefore, in such a case, in order to exclude the region where the contrast agent does not circulate from the color map image, a threshold luminance is set in the TIC, and a region not exceeding this is designated as 0 on the color map image. For example, the visibility of the color map image and the accuracy of the displayed information can be improved. However, a median filter may be applied to the color map image as necessary to remove mosaic noise from the color map image, thereby improving visibility.

  Next, a case where the display form is changed based on the color map image will be described. An example of an operation screen corresponding to this method is shown in FIG. FIG. 8 illustrates a method of changing the display form by setting the region of interest 81 on the color map image. In this method, color redistribution is determined within the range of the region of interest 81 set by the operator, and the determined color distribution is applied to the entire screen. Since this method can expand the color range of the region of interest, slight differences in parameters can be clearly distinguished by color differences.

  As shown in FIG. 10, it is also possible to set a reference area with a pointer or the like on the color map image and redistribute the colors between the parameters based on the parameter value corresponding to the reference area. FIG. 10 shows the case of a color map image indicating the inflow start time. When the operator designates a specific blood vessel as a reference area on the color map screen, the position of the corresponding color is displayed with an arrow on the color bar. FIG. 10 shows a color bar having a display range of 0 second to 20 seconds, and an arrow is displayed at a position of 8 seconds corresponding to the designated blood vessel region parameter. When the reference area is determined, the colors are redistributed with the parameters after 8 seconds, and the color map image is reconstructed. Note that the display range of the color bar is reset to the range of 8 to 20 seconds specified in the reference area. Incidentally, in the vicinity of the color bar, a converted value in which the parameter corresponding to the reference area is set to 0 second is also written together with the parameter value before the change. In FIG. 10, the converted value is shown in parentheses. Also in this case, the parameter range designated on the color map image is displayed in a form that allows the designated range such as shading to be identified on the TIC, as shown in FIG. Of course, the parameter usage range can be adjusted by changing the specified range on the TIC. By this processing, it is possible to evaluate in detail the difference in the start timing of the inflow of the contrast medium to the reference blood vessel.

  On the other hand, when the region on the color map image is changed or the parameter range is changed, the region portion outside the range of the color bar disappears from the color map image, so that it may be difficult to grasp the whole image. Therefore, in order to supplement the missing information, a color for displaying the missing information can be set in the color bar and supplemented by superimposing it on the color map image. For example, in the case of the color map image at the inflow start time shown in FIG. 10, by limiting the parameters to 8 seconds or later, information from 0 seconds to 7 seconds is lost. Therefore, as shown in FIG. 11, an out-of-range image of 0 to 7 seconds is prepared together with an in-range image composed of parameters of 8 to 20 seconds, and a superimposed image is formed by superimposing both images. 41 may be displayed.

  The above-described change in the display form of the color map image is executed starting from any one of the color bar, TIC, and color map image, but each change is reflected in other display units.

  It is also possible to select a specific contrast image from the reconstructed image and display the contrast image and a color map image constructed through arithmetic processing in a superimposed manner. FIG. 12 shows an example of this type of display. In this case, an image obtained by performing image processing such as blood vessel enhancement on the stored image can be used as the background image. As the background image, for example, an image in which the maximum TIC luminance or the average TIC luminance measured at each pixel is calculated and the blood vessel structure is emphasized can be used. It is also possible to display the constructed color map images in an overlapping manner. In addition, an image showing tissue elasticity, a CT image, an MRI image, or the like can be superimposed as a background image. Thus, the background image is not particularly limited.

(Summary)
As described above, when the ultrasonic diagnostic apparatus according to this embodiment is used, in addition to a color map image, commonly known medical images such as Doppler and contrast images, CT images, MRI images, and the like are the same. A display form that can be displayed in parallel or superimposed on the screen and that allows the operator or the observer to observe the observation region can be realized.

  In particular, it is effective to display color map images before and after treatment in parallel in determining the effect of a treatment method related to blood flow dynamics. For example, there is a treatment method in which a blood vessel serving as a nutrient supply path of a tumor is blocked by a laser, a drug, high sound pressure ultrasound, or the like, and a tumor in the downstream is necrotized. In determining the effect of this treatment, an important observation item is whether the blood flow is arterial or portal vein as well as the presence or absence of reperfusion of the blood flow after surgery. In arterial cases, insufficient occlusion of the blood vessels, and in case of portal veins, remodeling of detour blood vessels is suspected, and the content of additional treatment changes depending on each. Therefore, by using the ultrasonic diagnostic apparatus according to the embodiment that can display color map images before and after treatment in parallel and accurately compare the blood flow dynamics of both, improvement of diagnosis accuracy and improvement of treatment effect can be realized. be able to.

  In the above description, it has been described that the operator individually inputs information to each of the TIC calculation control unit 11, the drawing information input unit 13, and the display information input unit 15, but the information to be input is initially set. If it is input in advance as a set value, the operator's input work can be omitted. That is, a series of processes from acquisition of image data by the probe to image display can be automated.

  At that time, if the contents of the initial setting are packaged for each clinical use, the initial setting work by the operator can be simplified. For example, when using for tumor diagnosis of the liver, it is important to know the properties of tumor blood vessels and tumor tissue. In other words, the timing of the start of staining of tumor blood vessels and tumor tissue starting from the heart, the amount of contrast agent taken up by the liver Kupffer cells, and the like are important indicators. For example, in the example of FIG. 5, a combination of drawing information considered to be the minimum necessary such as the inflow start time, the duration, and the integral value among the nine drawing information is prepared as a liver tumor diagnosis package. In this case, the operator can automatically display necessary information on the display unit 17 without performing detailed settings simply by selecting the package for diagnosing the tumor of the liver.

(B) Example 2
Next, a second embodiment of the present invention will be described. In this embodiment, a case where the technique described in the first embodiment is extended to display of a three-dimensional image will be described. That is, a case where a three-dimensional image is displayed as a medical image will be described.

(overall structure)
FIG. 15 is a block diagram of an ultrasonic diagnostic apparatus according to the second embodiment. 15 corresponding to those in FIG. 1 are denoted by the same reference numerals. The ultrasonic diagnostic apparatus according to the second embodiment includes a probe 2, a transmission beam former 3, a reception beam former 4, an A / D converter 5, a D / A converter 6, a TGC (time gain compensation) 7, an envelope. Detection unit 8, scan converter (SC) 9, image memory 10, TIC calculation control unit 11, TIC calculation unit 12, drawing information input unit 13, parameter calculation unit 14, display information input unit 15, distribution image configuration unit 16, display A unit 17 and a transmission control unit 19 are included.

  The ultrasonic diagnostic apparatus shown in FIG. 15 is different from the ultrasonic diagnostic apparatus according to the first embodiment in that a transmission control unit 19 is added. Accordingly, the first embodiment and the second embodiment are basically the same with respect to other components. However, in the ultrasonic diagnostic apparatus according to this embodiment, the probe 2 that can image three-dimensional information is used. As long as the probe 2 can capture three-dimensional information, there is no particular limitation on the shape, internal configuration, and operation mode. For example, the one-dimensional array probe described in the first embodiment may be provided with a driving device such as a motor to mechanically move the probe or a probe having a two-dimensional array.

  The transmission control unit 19 is a device that controls a transmission sequence for acquiring a plurality of different cross-sectional image data. Therefore, the transmission control unit 19 controls the transmission beamformer 3 as a control target. The transmission sequence is determined by the size (azimuth direction, depth direction, slice direction) of the area from which the three-dimensional information is acquired, the frame rate of the image data, and the sampling interval when measuring the TIC. The TIC sampling interval needs to be about 4 Hz as described in the first embodiment. Therefore, when the frame rate of the image data is 20 Hz, it is possible to capture a maximum of five sections at different positions in the slice direction. When the area width in the slice direction for acquiring the three-dimensional information is set to 5 mm, the interval between the imaging sections is 1 mm, and this value is set as the interval when the probe 2 is moved in the slice direction. In order to increase the number of imaging sections and the sampling interval of TIC, it is only necessary to increase the frame rate at which image data is acquired. Adjust according to the usage of the operator.

(Color map image composition operation)
Since the TIC measurement based on the image data acquired through the probe 2, the input of drawing information, the calculation of parameters, and the display form of various information displayed on the display unit 17 are the same as in the first embodiment, the description will be given. Omitted.

  Next, the processing operation of the distribution image constructing unit 16 that realizes three-dimensional display of a color map image will be described. FIG. 16 shows an operation example during imaging. FIG. 16 shows a case where the imaging target is imaged at five different positions from the first imaging surface to the fifth imaging surface by moving the probe 2 of the one-dimensional array in the slice direction (indicated by the arrow direction). Assume. The transmission sequence sequentially captures images from the first imaging surface to the fifth imaging surface, and repeats this as one scan until the operator finishes the measurement. The acquired image data is distributed for each imaging section as shown in FIG. 17, and after TIC measurement and parameter calculation are performed, a two-dimensional color map image is formed.

  A noise removal filter such as a median filter is applied to each color map image. The configured two-dimensional color map image is three-dimensionally arranged at the position interval of each imaging surface at the time of imaging. The space generated between the imaging sections is complemented with pixels by linear interpolation processing or the like, and a three-dimensional color map image is formed. By making the color map image three-dimensional, the difference in blood flow dynamics between tissues can be observed in three dimensions.

  Of course, also in the case of the second embodiment, it is desirable to reduce the influence of the positional deviation of the imaging target that occurs during the TIC measurement. FIG. 18 shows a configuration example of an ultrasonic diagnostic apparatus equipped with the position correction vector calculation unit 18. FIG. 18 corresponds to the configuration of the first embodiment illustrated in FIG. However, the ultrasonic diagnostic apparatus shown in FIG. 18 is different in that the search range is expanded in three dimensions.

  In this embodiment, in the three-dimensional processing, as shown in FIG. 20, a reference region is set on the third imaging surface in FIG. 16 or FIG. First, a position where the difference absolute value between the reference area and the image data to be subjected to position correction is minimized is searched for in the same imaging plane, that is, among a plurality of other imaging planes belonging to the third imaging plane.

  Next, image data acquired at the same time phase (scan) as the previously searched image data is selected from the image data of the adjacent second imaging surface and fourth imaging surface, and a search area is set and evaluated. Calculate the minimum value of the indicator. Thereafter, the minimum values calculated on the respective imaging planes are compared, and the minimum area becomes the matching area, and the position correction vector is determined.

  A method of smoothing by comparing the TIC of the pixel of interest with the TIC of surrounding pixels is also applied in the same manner as in the first embodiment. The pixels used for correction may be selected from the same imaging surface, or may be selected from other adjacent imaging surfaces. The method of selecting the luminance for each time is the same as the method described in the first embodiment. The three-dimensional color map image can be displayed in parallel with or superimposed on the CT image or MRI image.

(C) Summary An ultrasonic diagnostic apparatus according to an embodiment includes a probe 2 for transmitting and receiving ultrasonic waves to and from an imaging target, and an image data configuration unit that configures image data based on a signal acquired by the probe. An image memory 10 for storing image data, a TIC calculation control unit 11 for controlling acquisition of image data and TIC measurement, a TIC calculation unit 12 for measuring TIC from luminance values on the image data, A parameter calculation unit 14 for calculating a parameter that gives a characteristic point of the TIC from the TIC, which is necessary for the configuration of the color map image, a distribution image configuration unit 16 for forming a color map image reflecting the blood flow dynamics from the parameter, It has a display unit 17 for displaying a color map image formed by the distribution image forming unit, and a display information input unit 15 for changing the display form of the displayed image. With this feature, it is possible to automatically create a color map image reflecting time axis information in the blood flow dynamics of the imaging target and provide it to the operator or the observer.

  Further, it is desirable that the TIC calculation control unit 11 is equipped with a function of setting a region of interest and a sampling interval setting function for image data to be stored. This setting function enables execution of control related to image data storage and TIC measurement processing.

  Further, in the TIC measurement in the TIC calculation unit 12, it is desirable to perform smoothing by averaging processing in the time direction while maintaining the number of measurement points. Smoothing can remove noise and other singularity information.

  In addition, it is desirable that the TIC measurement process in the TIC calculation unit 12 is executed for every pixel of the stored image data or for each preset region. It is desirable to select the region setting in consideration of the processing load and the capacity load of the image memory 10. If TIC is measured for all the pixels, fine image information about the imaging target 1 can be acquired. On the other hand, when the TIC measurement range is limited or the unit area for measuring the TIC is expanded to multiple pixels, processing load and capacity load can be reduced.

  In addition, the TIC calculation unit 12 measures the feature point of the luminance change that appears due to the reflux of the contrast agent by using a simplified approximate function set in advance, thereby processing load required for calculating the TIC feature point. Can be greatly reduced.

The approximate function used by the TIC calculation unit 12 for measuring the feature point is a constant value from the measurement start to the first time point, increases linearly from the first time point to the second time point, and increases from the second time point to the third time point. It has a constant value until the time point, and has a shape that linearly descends from the third time point, or a constant value from the start of measurement to the first time point, and after the first time point, the equilibrium luminance A, time t, inflow of contrast agent It is desirable that the luminance change associated with is given by a function y = A (1-e− ^βt ) that is generally known as β.

  The ultrasonic diagnostic apparatus described above preferably includes a drawing information input unit 13 for an operator to input drawing information necessary for image diagnosis. By specifying the drawing information to be calculated by the parameter calculation unit 14 through the drawing information input unit 13, the processing load for parameter calculation in the parameter calculation unit 14 and the color map image using the calculated parameters are drawn. Time reduction can be realized.

  The input of the drawing information here is preferably realized by the operator's input to the TIC reflecting the drawing information displayed on the navigation screen displayed on the display unit 17 and the information indicating the drawing information. Further, it is desirable that the input of the drawing information is omitted by setting the drawing information in advance.

  Further, it is desirable that the operator can freely edit the addition and deletion of display items and the change of the text on the navigation screen or the drawing information.

  The display unit 17 displays a still image or a moving image corresponding to the acquired image data, and a TIC corresponding to the region of interest ROI set on the still image or the moving image by the operator is parallel to the still image or the moving image. It is desirable to be displayed or superimposed. Note that the TIC to be superimposed is specified by specifying the region of interest ROI or TIC by the operator.

  Also, information input to the drawing information input unit 13 includes contrast agent inflow start time, equilibrium luminance arrival time, contrast agent disappearance start time, contrast agent duration, time to reach a preset threshold, and luminance increase It is desirable that the information be related to blood flow dynamics, such as rate or descent rate, brightness in equilibrium, and total flow rate.

  The parameter calculated by the parameter calculation unit 14 reflects information input to the drawing information input unit 13 and is a value calculated from TIC indicating a luminance change accompanying the reflux of the contrast agent. desirable.

  The distribution image formed by the distribution image forming unit 16 is preferably a color map image that is color-coded according to the parameter value calculated by the parameter calculating unit 14.

  The display form of the color map image on the display unit 17 is a combination of information to be displayed among drawing information, a still image or a moving image of acquired image data, a TIC of a region of interest designated by the operator, and a color map image. It is desirable that the operator can freely edit the arrangement and size.

  Further, it is desirable that the color map image formed by the distribution image forming unit 16 can optimize the color range within the region of interest ROI set on the color map image by the operator.

  In addition, the distribution image constructing unit 16 designates the range on the color bar indicating the relationship between the value of the parameter attached to the color map image and the display color with an arrow or the like, so that the color map image for the region included in the designated range. It is desirable to reconstruct With this function, the display color range can be optimized. The distribution image constructing unit 16 preferably has a function of reconstructing a color map image based on the reference region by designating the reference region on the color map image. Further, it is desirable that the distribution image forming unit 16 is equipped with a function that can limit the range of parameters displayed on the color map image when detecting an operation input on the TIC of the region of interest.

  In addition, the display information input unit 15 is configured to display a combination of drawing information to be displayed, a display size, a background image, and a reconstructed image based on information such as measured TIC, stored image data, and configured color map image. It is desirable to receive general display form information related to the combination of the two and reflect the received information on the distribution image forming unit 16 or the display unit 17.

  In addition, the distribution image forming unit 16 configures both a color map image included in the target parameter range and a color map image not included in the target parameter range. It is desirable to mount a function for displaying both images in a superimposed manner after distinguishing by color distribution.

  In addition, the distribution image forming unit 16 has a function of displaying a color map image, an ultrasonic image, an MRI image, a CT image, a PET image, and other images that show the same imaged object combined with different drawing information as a background image. It is desirable to install.

  Further, it is desirable that the distribution image forming unit 16 is provided with a function of displaying an image obtained by performing image processing such as blood vessel enhancement using the acquired image data as a background image and displaying a color map image superimposed thereon. .

  Further, it is desirable that the drawing information input unit 13 and the display information input unit 15 can set information input by the operator in advance before the operation, and can save the setting contents and reflect them next time. .

  The drawing information input unit 13 can set the drawing information to be displayed on the navigation screen by ranking based on the selection frequency on the operation history and the importance on diagnosis, or the operator can freely rearrange and display the drawing information. Is desirable.

  In addition, it is desirable that the above-described ultrasonic diagnostic apparatus includes the distribution image configuration unit 16 that configures a three-dimensional color map image that reflects blood flow dynamics based on the calculated parameters. With the three-dimensional display, the blood flow dynamics can be distinguished. In this case, the probe 2 can acquire image data on a plurality of different imaging surfaces such as a one-dimensional array type probe provided with a drive unit such as a motor, a two-dimensional array type probe, and the like. It is desirable to use one.

  In addition, the three-dimensional color map image configured in the distribution image configuration unit 16 is preferably configured by three-dimensionally combining two-dimensional color map images configured on different imaging surfaces.

  Further, it is desirable that the TIC measurement by the TIC calculation unit 12 is executed after the position correction vector calculation unit 18 corrects the positional deviation in the space to be imaged.

  The three-dimensional color map image formed by the distribution image forming unit 16 is a three-dimensional color map image composed of different drawing information, an ultrasonic image, an MRI image, a CT image, a PET image, or other images showing the same imaging target. Are preferably displayed in combination as a background image.

(D) Other Embodiments In the above-described embodiments, the case where the present invention is applied to an ultrasonic diagnostic apparatus has been described. That is, a case has been described in which a luminance change on image data captured using ultrasonic waves is measured in units of pixels as a TIC, and a parameter calculated based on the TIC is converted into a color map image. However, the feature of the present invention is not the image data acquisition method but the signal processing for the acquired image data. Therefore, the present invention can also be applied to processing of digital images other than ultrasonic images, for example, digital images such as MRI images and CT images.

  In each embodiment, the distribution value including the time axis information of blood flow dynamics is configured with the luminance value as the processing target, but the RF signal before being converted into the luminance value may be the processing target. When an RF signal is a processing target, a time change curve of the RF signal may be obtained by calculation, and a distribution image including time axis information of blood flow dynamics may be configured based on a parameter that defines the feature point.

  DESCRIPTION OF SYMBOLS 1 ... Imaging object, 2 ... Probe, 3 ... Transmission beam former, 4 ... Reception beam former, 5 ... A / D converter, 6 ... D / A converter, 7 ... TGC, 8 ... Envelope detection part, DESCRIPTION OF SYMBOLS 9 ... SC, 10 ... Image memory, 11 ... TIC calculation control part, 12 ... TIC calculation part, 13 ... Drawing information input part, 14 ... Parameter value calculation part, 15 ... Display information input part, 16 ... Distribution image structure part, DESCRIPTION OF SYMBOLS 17 ... Display part, 18 ... Position correction vector calculating part, 19 ... Transmission control part, 41 ... Display screen, 51 ... Navigation screen, 211 ... Observation target, 212 ... Measurement position of TIC.

Claims (14)

An image data configuration unit that configures image data for a tomographic plane to be imaged;
A time change curve calculation unit for calculating a time change curve from the image data;
A parameter calculation unit that calculates a parameter that defines a characteristic point of the time-varying curve;
A distribution image constituting unit constituting a distribution image including time axis information of blood flow dynamics from the parameters;
A medical image display apparatus. A position correction vector calculation unit for calculating a position correction vector between the image data corresponding to the imaging target;
The medical image display apparatus according to claim 1, wherein the time change curve calculation unit measures a time change curve based on image data whose position is corrected by the position correction vector. A drawing information input unit for inputting drawing information through the operation of the operator;
The medical image display apparatus according to claim 1, wherein the parameter calculation unit calculates a parameter for configuring a distribution image of blood flow dynamics based on the input drawing information. The drawing information is information related to blood flow dynamics, such as contrast agent inflow start time, equilibrium luminance arrival time, contrast agent disappearance start time, contrast agent duration, time to reach a preset threshold, luminance increase The medical image display device according to claim 3, wherein the medical image display device is at least one of a rate and a luminance decrease rate. The parameter calculation unit calculates a parameter for configuring a distribution image of blood flow dynamics for a feature point corresponding to the input drawing information among feature points of the time change curve. Item 4. The medical image display device according to Item 3. The medical image display apparatus according to claim 1, wherein the distribution image forming unit forms a two-dimensional or three-dimensional color map image as the distribution image by color coding according to the value of the parameter. A display information input unit for inputting display information by an operator;
The distribution image forming unit forms a distribution image of blood flow dynamics based on the drawing information, a still image or a moving image of acquired image data, a time change curve of a region of interest, and color coding according to the parameter. The medical image display apparatus described in 1. An image data composing unit constructing image data for a tomographic plane to be imaged;
A time change curve calculation unit calculating a time change curve from the image data;
A step of calculating a parameter for defining a characteristic point of the time-varying curve by a parameter calculation unit;
A step of forming a distribution image including time axis information of blood flow dynamics from a parameter by a distribution image configuration unit;
A method for constructing a distribution image of blood flow dynamics, comprising: The position correction vector calculation unit further includes a step of calculating a position correction vector between the image data corresponding to the imaging target;
The method for constructing a blood flow dynamic distribution image according to claim 8, wherein the step of calculating the time change curve measures the time change curve based on the image data position-corrected by the position correction vector. The method further includes a step of inputting drawing information through the operation of the operator,
The distribution image configuration of blood flow dynamics according to claim 8, wherein the step of calculating the parameter calculates parameters for forming a distribution image of blood flow dynamics based on the input drawing information. Method. Contrast agent inflow start time, equilibrium luminance arrival time, contrast agent disappearance start time, contrast agent duration, contrast agent time, time to reach a preset threshold, luminance increase The method of constructing a distribution image of blood flow dynamics according to claim 10, wherein at least one of a rate and a luminance decrease rate is obtained. The step of calculating the parameter calculates a parameter for constituting a distribution image of blood flow dynamics for a feature point corresponding to the input drawing information among the feature points of the time change curve. The method for constructing a distribution image of blood flow dynamics according to claim 10. The step of constructing the distribution image of the blood flow dynamics constructs a two-dimensional or three-dimensional color map image as the distribution image by color-coding according to the value of the parameter. Of distribution image of blood flow dynamics. The color map image is provided with a color bar indicating the correspondence between the color and the parameter value, and the parameter value range or color use range displayed on the color map image is displayed on the screen. The method for constructing a distribution image of blood flow dynamics according to claim 13, wherein the operator can freely change through an operation input.

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