CN118177865A

CN118177865A - Pulse Doppler ultrasound imaging method and ultrasound imaging device

Info

Publication number: CN118177865A
Application number: CN202211601632.4A
Authority: CN
Inventors: 向兰茜; 李双双
Original assignee: Shenzhen Mindray Bio Medical Electronics Co Ltd
Current assignee: Shenzhen Mindray Bio Medical Electronics Co Ltd
Priority date: 2022-12-13
Filing date: 2022-12-13
Publication date: 2024-06-14

Abstract

A pulsed doppler ultrasound imaging method and ultrasound imaging apparatus, the method comprising: acquiring a color Doppler blood flow image or a tissue Doppler image of a target object; acquiring initial imaging parameters for pulsed Doppler imaging; calculating the data volume to be acquired when pulse Doppler imaging is carried out according to the initial imaging parameters, and comparing the data volume with a preset data volume threshold; acquiring pulse Doppler imaging data based on the initial imaging parameters when the data volume does not exceed a preset data volume threshold; when the data volume exceeds a preset data volume threshold, adjusting initial imaging parameters so that the data volume to be acquired does not exceed the preset data volume threshold when pulse Doppler imaging is performed according to the adjusted imaging parameters, and acquiring pulse Doppler imaging data based on the adjusted imaging parameters; and storing the acquired pulse Doppler imaging data for pulse Doppler offline analysis. The method can limit the amount of data for offline analysis to an acceptable range.

Description

Pulse Doppler ultrasound imaging method and ultrasound imaging device

Technical Field

The application relates to the technical field of ultrasonic imaging, in particular to a pulse Doppler ultrasonic imaging method and an ultrasonic imaging device.

Background

Pulse Doppler imaging (Pulsed Wave Doppler, PW for short) is one of the necessary imaging means on ultrasonic equipment, and is widely applied to quantitative measurement of blood flow. When blood flow information of a specific physiological structure or a focus area needs to be observed, a clinician generally adopts color Doppler (Color Doppler Flow Imaging, abbreviated as CDFI) to observe blood flow conditions, then uses blood flow position information provided by CDFI to perform PW sampling, starts a PW imaging mode, performs spectrum analysis of blood flow in a specific sampling volume, and performs measurement of relevant parameters of blood flow dynamics through the result of the spectrum analysis.

The conventional PW imaging mode is generally in a real-time imaging state, that is, after a doctor selects a PW sampling gate on the basis of CDFI images, the doctor starts the PW imaging mode, at this time, CDFI images are frozen, and the PW imaging mode starts scanning, performs transmission, reception and signal processing of the PW mode, and finally displays spectrum information in a corresponding sampling volume on a screen. In this mode of operation, the physician typically selects only one PW sampling gate, and the probe must remain stationary during the PW scan to maintain accuracy of the sampling position.

Based on this, an offline PW imaging mode may be employed. In an offline PW imaging mode, that is, in a CDFI imaging state, after a doctor selects an observation section, the doctor starts to acquire original data for a specific period of time, the original data after the data acquisition is completed are stored in corresponding media, after the process is completed, the doctor does not need to maintain a real-time mapping state, the probe can be freely placed, and the subsequent processes of spectrum imaging and quantitative analysis are performed based on the original data in the storage media.

The offline PW imaging mode has the advantages over the real-time PW imaging mode: the doctor does not need to consider the two operations of probe mapping stability and on-machine spectrum sampling analysis, and can concentrate on PW sampling gate selection and corresponding quantitative analysis after data acquisition is completed; because the acquired raw data actually covers a larger ROI imaging range of the region of interest (Region of Interested), a plurality of different PW sampling gates in the ROI can be supported to be selected in the PW analysis process, and quantitative measurement results of a plurality of different positions can be obtained through one analysis. However, since a clinical scenario generally requires a larger PW imaging data volume for offline analysis, the offline PW imaging mode is limited by the original data storage medium (including the buffer size of the ultrasound system, the space size of the storage medium, and the read/write rate, etc.), and the data volume of a single data acquisition that can be supported by the offline PW imaging mode should be controlled within a certain range to ensure usability.

Therefore, how to limit the PW imaging data volume for offline analysis to an acceptable range under different clinical scenarios is an important issue in offline PW imaging protocols.

Disclosure of Invention

In one aspect of the present application, a pulse doppler ultrasound imaging method is provided, which is characterized in that the method comprises: acquiring a color Doppler blood flow image or a tissue Doppler image of a target object; acquiring initial imaging parameters for pulse Doppler imaging of the color Doppler blood flow image or tissue Doppler image; calculating the data volume to be acquired when pulse Doppler imaging is carried out by using the initial imaging parameters, and comparing the data volume with a preset data volume threshold; when the data quantity does not exceed the preset data quantity threshold value, controlling an ultrasonic probe to acquire pulse Doppler imaging data based on the initial imaging parameters; when the data volume exceeds the preset data volume threshold, adjusting the initial imaging parameters so that the data volume to be acquired does not exceed the preset data volume threshold when pulse Doppler imaging is performed by the adjusted imaging parameters, and controlling an ultrasonic probe to acquire pulse Doppler imaging data based on the adjusted imaging parameters; and storing the acquired pulse Doppler imaging data, wherein the pulse Doppler imaging data are used for pulse Doppler offline analysis.

According to another aspect of the present application there is provided a pulsed doppler ultrasound imaging method, the method comprising: acquiring a color Doppler blood flow image or a tissue Doppler image of a target object; acquiring a region of interest for pulse doppler imaging of the color doppler blood flow image or tissue doppler image; controlling an ultrasonic probe to acquire pulse Doppler imaging data of the region of interest; and storing part of data in the acquired pulse Doppler imaging data, wherein the part of data is used for pulse Doppler offline analysis, and the part of data corresponds to pulse Doppler imaging data corresponding to one or more subareas in the region of interest.

According to still another aspect of the present application, there is provided an ultrasound imaging apparatus comprising a transmit receive circuit, an ultrasound probe, a processor, and a memory, wherein: the transmitting and receiving circuit is used for controlling the ultrasonic probe to transmit ultrasonic waves to a target object, receiving echoes of the ultrasonic waves and acquiring ultrasonic echo data from the echoes; the processor is used for controlling the transmitting and receiving circuit and executing the pulse Doppler ultrasonic imaging method to acquire pulse Doppler imaging data and determine data to be stored for pulse Doppler off-line analysis; the memory is used for storing the data for pulse Doppler offline analysis.

According to the pulse Doppler ultrasound imaging method and the ultrasound imaging device, before PW imaging is carried out, whether the data volume to be acquired exceeds a preset data volume threshold value or not is calculated, if not, PW imaging data is acquired in real time by the initial imaging parameters, if yes, the imaging parameters are adjusted so that the data volume to be acquired does not exceed the preset data volume threshold value when PW imaging is carried out by the adjusted imaging parameters, then PW imaging data is acquired in real time, the acquired data is used for offline PW analysis, and the data volume for offline analysis can be limited within an acceptable range in any clinical scene. In addition, when the imaging parameters are adjusted, default imaging parameters can be preferentially adjusted, and settable imaging parameters set by a user are little adjusted or not adjusted, so that the method not only meets the index requirements of spectrum analysis (ensures the feasibility and certain flexibility of spectrum analysis) of a clinician in any clinical application scene, but also controls the original data volume within the allowable range of the system.

Drawings

The above and other objects, features and advantages of the present invention will become more apparent from the following more particular description of embodiments of the present invention, as illustrated in the accompanying drawings. The accompanying drawings are included to provide a further understanding of embodiments of the invention and are incorporated in and constitute a part of this specification, illustrate the invention and together with the embodiments of the invention, and not constitute a limitation to the invention. In the drawings, like reference numerals generally refer to like parts or steps.

Fig. 1 shows a typical PW application scenario schematic.

FIG. 2 shows an offline PW analysis application scenario schematic.

Figure 3 shows a schematic flow chart of a pulsed doppler ultrasound imaging method according to one embodiment of the application.

Fig. 4 shows a schematic diagram of an original region of interest and sub-regions therein in a pulsed doppler ultrasound imaging method according to one embodiment of the application.

Figure 5 shows a schematic flow chart of a pulsed doppler ultrasound imaging method according to another embodiment of the application.

Fig. 6 shows a schematic block diagram of an ultrasound imaging apparatus according to an embodiment of the present application.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, exemplary embodiments according to the present invention will be described in detail with reference to the accompanying drawings. It should be apparent that the described embodiments are only some embodiments of the present invention and not all embodiments of the present invention, and it should be understood that the present invention is not limited by the example embodiments described herein. Based on the embodiments of the invention described in the present application, all other embodiments that a person skilled in the art would have without inventive effort shall fall within the scope of the invention.

As described above, PW is one of the necessary imaging means on ultrasound equipment, and is widely used for quantitative measurement of blood flow. When blood flow information of a specific physiological structure or a focus area needs to be observed, a clinician generally adopts CDFI to observe blood flow condition, then uses blood flow position information provided by CDFI to perform PW sampling, starts a PW imaging mode, performs spectrum analysis of blood flow in a specific sampling volume, and performs measurement of hemodynamic related parameters through a result of the spectrum analysis, as shown in fig. 1.

Fig. 1 shows a typical PW application scenario schematic. As shown in fig. 1, CDFI images 110 can display blood flow information within the ROI; PW sampling gate 120 is a location area set according to the blood flow location shown in CDFI images 110; the PW imaging mode obtains a blood flow spectrum image 130, and can determine the blood flow velocity distribution and the change condition of the blood flow along with different cardiac cycles according to the spectrum morphology; from PW imaged blood flow spectrum image 130, a measurement interval may be selected, and a corresponding hemodynamic parameter index 140 is measured and displayed.

The conventional PW imaging mode is generally a real-time imaging state, that is, after a doctor selects a PW sampling gate on the basis of CDFI images, the doctor starts the PW imaging mode, at this time, the image is frozen CDFI, and the PW imaging mode starts scanning, performs transmission, reception and signal processing of the PW mode, and finally displays spectrum information in a corresponding sampling volume on a screen, as described above in connection with fig. 1. In this mode of operation, the physician typically has to select only one PW sampling gate, and the probe must remain stationary during the PW scanning process to maintain the accuracy of the sampling position, which is inconvenient.

The present application is directed to techniques in an offline PW imaging mode. In an offline PW imaging mode, that is, in the CDFI imaging state, after a doctor selects an observation section, the doctor starts to acquire original data for a specific period of time (typically 3-5 seconds), and after the data acquisition is completed, the original data is stored in a corresponding medium. After the process is finished, the doctor does not need to maintain the state of real-time mapping, and the probe can be freely placed. The subsequent process of spectral imaging and quantitative analysis is based on raw data in the storage medium, which means two advantages: the doctor does not need to consider the two operations of probe mapping stability and on-machine spectrum sampling analysis, and can concentrate on PW sampling gate selection and corresponding quantitative analysis after data acquisition is completed; because the acquired raw data actually covers a larger ROI imaging range, in the PW analysis process, a plurality of different PW sampling gates in the ROI can be supported for selection, and quantitative measurement results at a plurality of different positions can be obtained through one analysis, as shown in fig. 2.

FIG. 2 shows an offline PW analysis application scenario schematic. As shown in fig. 2, the raw data acquisition includes the entire color doppler ROI range 210; multiple PW sampling gates 220 are selected based on the raw data for multi-location spectral analysis.

In operational flow, the offline PW analysis has the above advantages over the conventional real-time PW imaging mode. But generally requires a larger amount of PW imaging data for offline analysis due to clinical scenarios. For example, first, to meet the requirements of clinical spectral analysis, the data acquisition duration cannot be typically less than 3 seconds (the longer the data acquisition duration, the proportionally increased amount of raw data); second, spectral analysis requires that the PW scale must be greater than the maximum flow rate of the analysis subject, so for higher flow rates, the higher the pulse repetition frequency (Pulse Repetition Frequency, abbreviated as PRF) of the raw data acquisition (higher data acquisition PRF, proportionally increased raw data volume); finally, the ROI range of the raw data acquisition needs to include as much as possible all possible regions of interest, thus allowing the physician freedom to place PW sampling gates on all regions of interest when analyzing offline (the larger the ROI range of the raw data acquisition, the proportionally increased amount of raw data). All of the above clinical demands tend to be larger amounts of raw data, but are in fact limited by the raw data storage media (including the ultrasound system buffer size, the storage media space size, and the read-write rate, etc.), the amount of data that can be supported for a single data acquisition should be controlled within a certain range to ensure ease of use.

The offline PW imaging mode is limited by the original data storage medium (including the buffer size of the ultrasound system, the space size of the storage medium, and the read-write rate), and the data volume of single data acquisition that can be supported by the offline PW imaging mode should be controlled within a certain range to ensure usability.

Based on this, the present application provides a pulsed doppler ultrasound imaging solution that solves the above-mentioned problems. Described below in connection with fig. 3 to 6.

Figure 3 shows a schematic flow chart of a pulsed doppler ultrasound imaging method 300 according to one embodiment of the application. As shown in fig. 3, the pulsed doppler ultrasound imaging method 300 may include the steps of:

in step S310, a color doppler blood flow image or a tissue doppler image of the target object is acquired.

In step S320, initial imaging parameters for pulse doppler imaging of a color doppler blood flow image or a tissue doppler image are acquired.

In step S330, the amount of data to be acquired when pulsed doppler imaging is performed with the initial imaging parameters is calculated and compared with a preset data amount threshold. When the data amount does not exceed the preset data amount threshold, step S340 is performed; when the data amount exceeds the preset data amount threshold, step S350 is performed.

In step S340, the ultrasound probe is controlled to acquire pulsed doppler imaging data based on the initial imaging parameters.

In step S350, the initial imaging parameters are adjusted so that the amount of data to be acquired when pulse doppler imaging is performed with the adjusted imaging parameters does not exceed a preset data amount threshold, and the ultrasound probe is controlled to acquire pulse doppler imaging data based on the adjusted imaging parameters.

In step S360, the acquired pulse doppler imaging data is stored, and the pulse doppler imaging data is used for pulse doppler offline analysis.

In embodiments of the present application, the data volume threshold and initial imaging parameters for PW imaging may be preset, and after a color doppler blood flow image, i.e., CDFI images or tissue doppler TDI images (suitable for measuring myocardial motion conditions) are obtained, the initial imaging parameters for PW imaging, such as data acquisition duration, maximum measurement speed, region of interest, scan line density, downsampling rate, etc., may or may not be adjusted based on CDFI images or TDI images. Based on the initial imaging parameters, the amount of data to be acquired when PW imaging is performed at the initial imaging parameters may be calculated, and it is determined whether the amount of data exceeds a preset data amount threshold. If the data volume to be acquired when the initial imaging parameters are used for PW imaging is calculated to be not more than the preset data volume threshold, the initial imaging parameters can be directly used for acquiring PW imaging data, and the acquired PW imaging data are stored for pulse Doppler offline analysis. In this case, the data volume acquired by PW parameter acquisition with the initial imaging parameter does not exceed the preset data volume threshold, that is, the data volume is within a certain range, so that the data volume to be stored for offline analysis can be satisfied within an acceptable range. If the calculated data volume to be acquired when PW imaging is performed with the initial imaging parameters exceeds the preset data volume threshold, the initial imaging parameters are adjusted at this time, such as the data acquisition duration, the maximum measurement speed, the region of interest, the scan line density, the downsampling rate, or at least one other imaging parameter, as described above, so that the data volume to be acquired when PW imaging is performed with the adjusted imaging parameters does not exceed the preset data volume threshold, and then the PW imaging parameters are acquired with the adjusted imaging parameters, and the acquired PW imaging data is stored for pulse doppler offline analysis. In this case, the data volume acquired by performing PW parameter acquisition with the initial imaging parameter may exceed a preset data volume threshold, and at this time, the data volume is reduced by adjusting the initial imaging parameter, and finally, the data volume acquired by performing PW parameter acquisition with the adjusted imaging parameter may not exceed the preset data volume threshold, and the data volume to be stored for offline analysis is limited within an acceptable range.

Therefore, the pulse doppler ultrasound imaging method 300 according to the embodiment of the present application calculates whether the amount of data to be acquired when PW imaging is performed with the initial imaging parameters exceeds the preset data amount threshold before PW imaging is performed, if not, acquires PW imaging data with the initial imaging parameters, and if so, adjusts the imaging parameters so that the amount of data to be acquired when PW imaging is performed with the adjusted imaging parameters does not exceed the preset data amount threshold, and acquires PW imaging data again, thereby enabling to limit the amount of data for offline analysis to an acceptable range in any clinical scenario.

In an embodiment of the present application, the initial imaging parameters described above may include default imaging parameters and settable imaging parameters, wherein the adjusting the initial imaging parameters described in step S350 may include: the default imaging parameters are preferentially adjusted. In this embodiment, when the amount of data to be acquired exceeds the preset data amount threshold when PW imaging is performed with the initial imaging parameters, and when the parameters need to be adjusted, the default imaging parameters are preferably adjusted, that is, the settable imaging parameters are not adjusted as much as possible, so that the data to be acquired is reduced, and such an imaging parameter adjustment manner can better meet the clinical scene requirement under the condition that the amount of data is limited within an acceptable range. Because default imaging parameters are default, fixed, and not user-settable, settable imaging parameters, as the name implies, are automatically or manually settable, specific needs are typically met by automatically or manually setting the settable imaging parameters (such as a patient's condition requiring a larger ROI range of data or requiring a longer data acquisition duration, etc.). In this case, by calculation, when it is determined that the amount of data acquired by PW imaging data based on the set settable imaging parameters and the default imaging parameters will exceed the preset data amount threshold, the default imaging parameters may be preferentially adjusted, for example, after one or more default imaging parameters are adjusted, by calculation, the amount of data acquired by PW imaging data with the adjusted imaging parameters will not exceed the preset data amount threshold, and (the set value of) the set imaging parameters is retained, so that the specific requirements of the clinical scenario can be satisfied, and the amount of data for offline analysis is limited within an acceptable range.

If the data volume obtained by PW imaging data acquisition with the adjusted imaging parameters still exceeds the preset data volume threshold after all default imaging parameters are adjusted, the settable imaging parameters, for example, the unset settable parameters, may be selectively adjusted. For example, the settable parameters include parameters a, b, c and d, which are currently set only automatically or manually according to the need, and parameters c and d are not set, so that the parameter values of c and d may be default recommended parameter values, in which case the settable parameters c and d may continue to be adjusted when it is found that adjustment is still needed after all other default imaging parameters are adjusted, so that the set settable parameters a and b are not yet adjusted, so that the specific need of the clinical scenario can still be met with reduced data volume. Of course, generally, the adjustment range of the default imaging parameters can be increased as long as the default imaging parameters are within the allowable range (for example, the requirement of basic image quality is met), so that the data volume requirement can be met only by adjusting the default imaging parameters. Of course, various requirements can be comprehensively considered, the adjustment amplitude of certain key default imaging parameters is reduced, and the adjustment amplitude of other non-key default imaging parameters is improved. Overall, the default imaging parameters are preferentially adjusted to better meet clinical scenario requirements while limiting the amount of data to within an acceptable range.

In an embodiment of the present application, acquiring settable imaging parameters from the initial imaging parameters may include: acquiring at least one settable imaging parameter based on user input; and/or acquiring at least one settable imaging parameter based on the automatic identification of the color doppler blood flow image. In this embodiment, the set results of settable imaging parameters may be obtained based on user input and/or automatic recognition of color Doppler blood flow images or tissue Doppler images. The acquisition of the settable imaging parameters based on user input is that the user sets the values of the settable imaging parameters, which generally reflects the specific needs of the user, so that the default imaging parameters are preferentially adjusted, the user needs can be better met under the condition that the data volume is limited within an acceptable range, and the user needs are also generally obtained from clinical scene needs, so that the clinical scene needs can be better met. The system automatically sets the value of the settable imaging parameter based on the automatic identification result of the color Doppler blood flow image or the tissue Doppler image, which generally reflects the specific requirement of clinical scenes, so that the default imaging parameter is preferentially adjusted, the clinical scene requirement can be better met under the condition that the data volume is limited within an acceptable range, and the user operation is reduced and the convenience is improved due to the automatic setting.

In a further embodiment of the present application, settable imaging parameters acquired based on user input may be set as non-adjustable parameters. Thus, in the adjustment of the imaging parameters in step S350, the settable imaging parameters acquired based on the user input are not adjustable, and only the imaging parameters other than them are adjusted, which can further ensure that the user demand is satisfied with the data amount being limited within the acceptable range.

In one example, the settable imaging parameters may include at least one of the following: one or more regions of interest for pulsed doppler imaging, acquisition duration, pulse repetition frequency, maximum measurement speed. In this example, examples of settable imaging parameters are given that can be key indicators for doctor-locked offline spectral analysis. The data acquisition time is generally in seconds, such as 2.5 seconds or 3 seconds. The maximum measurement speed is typically in units of cm/s, for example 5 cm/s or 10 cm/s. The maximum measurement speed is the maximum flow rate of the analysis object, and in general spectrum analysis requires that the PW scale must be larger than the maximum flow rate of the analysis object, so that for a blood flow with a higher flow rate, the pulse repetition frequency of the raw data acquisition is higher, that is, both the pulse repetition frequency and the maximum measurement speed have a correspondence relationship, and one of them may be set.

In the settable imaging parameters described above, the region of interest for pulsed doppler imaging may be the original region of interest for color doppler blood flow imaging or tissue doppler imaging, or one or more sub-regions within the original region of interest. The sub-region may be understood as a minimum analysis region for PW imaging, which, by setting such a minimum analysis region, helps to reduce the amount of data to be acquired before PW imaging, makes the subsequent process of imaging parameter adjustment easier (because the reduced amount can meet the data amount requirement) or limits the data set to an acceptable range without subsequent imaging parameter adjustment.

Fig. 4 shows a schematic diagram of an original region of interest and sub-regions therein in a pulsed doppler ultrasound imaging method according to one embodiment of the application. In fig. 4, a raw region of interest 410 for color doppler imaging is shown, along with two sub-regions 420 therein. The sub-region 420 is a subset of the original region of interest 410, and may contain only vessels of interest to the physician that require further spectral analysis. Although two sub-regions (SubROI) are shown in fig. 4, the number of sub-regions may be one or more.

In the embodiment of the application, the subareas can be defined manually by a doctor, and can be selected semi-automatically or automatically according to specific clinical application scenes by combining a corresponding intelligent recognition algorithm. The shape of the sub-region is also not limited to rectangular, but may be a more complex irregular shape, such as a shape that includes only that portion of the vascular architecture.

In one example, the default imaging parameters described previously may include scan line density and/or downsampling rate. In this example, when initial imaging parameters need to be adjusted, scan line density and/or downsampling rate may be preferentially adjusted, and these indices generally need not necessarily have specific values in the clinical scene, so by adjusting them to reduce the amount of data to be acquired, the requirements of the clinical scene are not impacted.

In a further embodiment of the present application, storing the acquired pulse doppler imaging data in step S360 may include: storing all data of the acquired pulse Doppler imaging data, wherein all data are used for pulse Doppler offline analysis; or based on user input, storing part of data in the acquired pulse Doppler imaging data, wherein the part of data is used for pulse Doppler offline analysis. In this embodiment, after the data acquisition is completed, all the acquired data may be stored for PW offline analysis, or a part of the acquired data may be stored for PW offline analysis. Since the amount of data acquired before data acquisition is determined not to exceed the preset data amount, the requirement that the amount of data is within an acceptable range can be met even if the entire data is stored, and storing the entire data can provide more flexibility for subsequent offline spectral analysis (because the amount of data is large, the range of selectable ROIs is wide) relative to storing portions of the data. On the other hand, the data can be further reduced before storage, for example, the data of the sub-region in the region of interest can be further acquired in all the data based on user input, so that the data volume to be stored can be further reduced, the flexibility of the subsequent offline spectrum analysis is reduced, the subsequent offline spectrum analysis is more targeted, and the efficiency of the offline spectrum analysis is improved.

In a further embodiment of the present application, comparing the data amount with the preset data amount threshold in step S330 may include: and acquiring a preset data quantity threshold value to be compared from a plurality of preset data quantity threshold values based on user input, and comparing the data quantity with the preset data quantity threshold value to be compared. In this embodiment, a plurality of preset data amount thresholds are provided, the thresholds may be classified (for example, a small threshold is 600MB, a medium threshold is 1GB, and a large threshold is 2 GB), and one preset data amount threshold may be selected according to user requirements, so that the user requirements can be met more flexibly. For example, in different clinical scenarios, when the user desires a higher quality of raw data, the parameter adjustment is performed according to a maximum data amount threshold, and when the user desires as little raw data as possible, the imaging parameter adjustment is performed according to a minimum data amount threshold.

At a later offline analysis, a stored color Doppler blood flow image (e.g., the color Doppler blood flow image acquired in step S310) or tissue Doppler image may be displayed, and one or more sampling gates may be selected within the region of interest of the color Doppler blood flow image or tissue Doppler image for pulse Doppler imaging; data corresponding to one or more sampling gates is acquired from stored pulse Doppler imaging data, and a pulse Doppler image corresponding to the one or more sampling gates is generated and displayed based on the acquired data. The pulsed doppler image shows a velocity-time curve of a blood flow signal or a myocardial motion signal, with the abscissa representing time and the ordinate representing velocity. The curve represents the frequency shift information of all red blood cells or particles on cardiac muscle in the sampling gate and between the moments, and the quantitative diagnosis of blood flow can be performed according to the form, amplitude, brightness and other indexes of the curve. Thus, by displaying the pulsed Doppler image, the user may be enabled to select a measurement interval on the pulsed Doppler image by user input, and based on the user input, measure and display a corresponding hemodynamic parameter index, such as systolic maximum flow velocity (PSV), diastolic minimum flow velocity (EDV), blood flow Resistance Index (RI), vascular Pulsation Index (PI), or the like.

A pulsed doppler ultrasound imaging method 300 according to an embodiment of the application is exemplarily shown above. Based on the above description, the pulse doppler ultrasound imaging method 300 according to the embodiment of the present application calculates, before PW imaging is performed, whether the amount of data to be acquired when PW imaging is performed with the initial imaging parameters exceeds the preset data amount threshold, if not, acquires PW imaging data in real time with the initial imaging parameters, if so, adjusts the imaging parameters so that the amount of data to be acquired when PW imaging is performed with the adjusted imaging parameters does not exceed the preset data amount threshold, acquires PW imaging data in real time, and acquires the acquired data for offline PW analysis, so that the amount of data for offline analysis can be limited within an acceptable range in any clinical scenario. In addition, when the imaging parameters are adjusted, default imaging parameters can be preferentially adjusted, and settable imaging parameters set by a user are little adjusted or not adjusted, so that the method not only meets the index requirements of spectrum analysis (ensures the feasibility and certain flexibility of spectrum analysis) of a clinician in any clinical application scene, but also controls the original data volume within the allowable range of the system.

A pulsed doppler ultrasound imaging method according to another embodiment of the application is described below in conjunction with fig. 5. Figure 5 shows a schematic flow chart of a pulsed doppler ultrasound imaging method 500 according to another embodiment of the application. As shown in fig. 5, a pulsed doppler ultrasound imaging method 500 may include the steps of:

In step S510, a color doppler blood flow image or a tissue doppler image of the target object is acquired.

In step S520, a region of interest for pulse doppler imaging of a color doppler blood flow image or a tissue doppler image is acquired.

In step S530, the ultrasound probe is controlled to acquire pulsed doppler imaging data of the region of interest.

In step S540, a portion of the acquired pulse doppler imaging data is stored, where the portion of the data is used for pulse doppler offline analysis, and the portion of the data corresponds to pulse doppler imaging data corresponding to one or more sub-regions within the region of interest.

In the embodiment of the application, after a color Doppler blood flow image, namely CDFI images or tissue Doppler TDI images are obtained, an interesting region for PW imaging can be adjusted or not adjusted based on CDFI images or TDI images, and an ultrasonic probe is controlled to acquire PW imaging data of the interesting region; after acquiring PW imaging data of a region of interest, storing PW imaging data for offline analysis, instead of storing all acquired PW imaging data, only a portion of the acquired PW imaging data is stored, which corresponds to PW imaging data within one or more sub-regions of the region of interest for PW imaging. After PW imaging is acquired, the amount of data stored may be reduced by storing only PW imaging data in one or more sub-regions of the imaging data corresponding to the region of interest, thereby achieving a limit to the amount of data to be stored for offline analysis within an acceptable range.

Thus, pulse Doppler ultrasound imaging method 500 according to an embodiment of the present application stores only a portion of PW imaging data after PW imaging is performed, the portion of data corresponding to PW imaging data in one or more sub-regions in a region of interest for PW imaging, enabling limiting the amount of data for offline analysis to within an acceptable range in any clinical scenario. In addition, since the accurate PW imaging data of the subarea for offline analysis is stored before offline analysis, the area with less analysis requirement can not be seen any more during offline analysis, so that the offline analysis is more targeted, and the efficiency of the offline analysis is improved.

In an embodiment of the present application, the partial data stored in step S540 is determined based on user input and/or automatic identification of PW imaging data. In this embodiment, after PW imaging data of the region of interest is acquired, PW imaging data in a sub-region that the user desires to store may be acquired based on user input, PW imaging data in a sub-region that has a higher analysis requirement may be acquired based on automatic identification of PW imaging data, or a combination of both. The PW imaging data to be stored is determined based on the user input, and the user sets the region to be analyzed offline, which reflects the specific requirement of the user, so that the PW imaging data in the region is stored, the user requirement can be better met under the condition of reducing the data amount to be stored, and the user requirement is generally obtained from the clinical scene requirement, so that the clinical scene requirement can be better met. Based on the automatic identification result of PW imaging data, PW imaging data to be stored is obtained, the system automatically identifies the region of interest corresponding to PW imaging data, so that the region of interest is determined to have one or more subareas (such as a region only comprising a blood vessel framework) possibly requiring offline analysis, the subareas to be analyzed are further accurately positioned, which generally reflects the specific requirement of clinical scenes, therefore, the PW imaging data in the region is stored, the clinical scene requirement can be better met under the condition of reducing the data quantity to be stored, and because the automatic identification and storage are realized, the user operation is reduced, and the convenience is improved.

In an embodiment of the present application, determining partial data based on user input may include: selecting one or more sub-regions in a region of interest for pulsed Doppler imaging based on user input; partial data corresponding to one or more sub-regions is determined from the pulsed Doppler imaging data. This embodiment provides an example way to acquire the partial data to be stored through user input, that is, by looking back at PW images of the region of interest, the user can input and select one or more sub-regions in the PW images from the user's own, so as to store PW imaging data corresponding to the selected sub-regions.

In an embodiment of the present application, determining partial data based on automatic identification of pulsed Doppler imaging data may include: automatically identifying the pulse Doppler imaging data, and determining one or more subareas according to the identification result; partial data corresponding to one or more sub-regions in the pulsed Doppler imaging data is determined. This embodiment provides an example way to acquire partial data to be stored by automatic identification, i.e. by automatically identifying PW imaging data of a region of interest, from which one or more sub-regions for which offline analysis is required can be identified to store PW imaging data corresponding to the sub-regions.

At a later offline analysis, a stored color Doppler blood flow image (e.g., the color Doppler blood flow image acquired in step S510) or tissue Doppler image may be displayed, and one or more sampling gates may be selected within the region of interest of the color Doppler blood flow image or tissue Doppler image for pulse Doppler imaging; data corresponding to one or more sampling gates is acquired from stored pulse Doppler imaging data, and a pulse Doppler image corresponding to the one or more sampling gates is generated and displayed based on the acquired data. The pulsed doppler image shows a velocity-time curve of a blood flow signal or a myocardial motion signal, with the abscissa representing time and the ordinate representing velocity. The curve represents the frequency shift information of all red blood cells or particles on cardiac muscle in the sampling gate and between the moments, and the quantitative diagnosis of blood flow can be performed according to the form, amplitude, brightness and other indexes of the curve. Thus, by displaying the pulsed Doppler image, the user may be enabled to select a measurement interval on the pulsed Doppler image by user input, and based on the user input, measure and display a corresponding hemodynamic parameter index, such as systolic maximum flow velocity (PSV), diastolic minimum flow velocity (EDV), blood flow Resistance Index (RI), vascular Pulsation Index (PI), or the like.

The above exemplarily illustrates a pulse doppler ultrasound imaging method 500 according to an embodiment of the present application. Based on the above description, pulse doppler ultrasound imaging method 500 according to an embodiment of the present application stores only a portion of PW imaging data after PW imaging, which corresponds to PW imaging data within one or more sub-regions in a region of interest for PW imaging, enabling limiting the amount of data for offline analysis to within an acceptable range in any clinical scenario. In addition, since the accurate PW imaging data of the subarea for offline analysis is stored before offline analysis, the area with less analysis requirement can not be seen any more during offline analysis, so that the offline analysis is more targeted, and the efficiency of the offline analysis is improved.

An ultrasound imaging apparatus provided in accordance with another aspect of the present application is described below in conjunction with fig. 6. Fig. 6 shows a schematic block diagram of an ultrasound imaging apparatus 600 according to an embodiment of the present application. As shown in fig. 6, the ultrasound imaging apparatus 600 may include a transmit receive circuit 610, an ultrasound probe 620, a processor 630, and a memory 640. Wherein: the transmitting-receiving circuit 610 is used for controlling the ultrasonic probe 620 to transmit ultrasonic waves to a target object, receiving echoes of the ultrasonic waves, and acquiring ultrasonic echo data from the echoes; the processor 630 is used to control the transmit receive circuitry and to perform the pulsed doppler ultrasound imaging method 300 or 500 described above in accordance with an embodiment of the present application to acquire pulsed doppler imaging data and determine data to be stored for pulsed doppler offline analysis; the memory 640 is used to store data for pulse doppler offline analysis. While the pulsed Doppler ultrasound imaging methods 300 and 500 have been described in detail in accordance with embodiments of the application, those skilled in the art can understand the structure and operation of the ultrasound imaging apparatus 600 in conjunction with the foregoing description, and only some of the main operations are described herein for brevity.

In one embodiment of the application, processor 630 may perform the following operations: acquiring a color Doppler blood flow image or a tissue Doppler image of a target object; acquiring initial imaging parameters for pulse Doppler imaging of a color Doppler blood flow image or a tissue Doppler image; calculating the data volume to be acquired when pulse Doppler imaging is carried out according to the initial imaging parameters, and comparing the data volume with a preset data volume threshold; when the data quantity does not exceed a preset data quantity threshold value, controlling the ultrasonic probe to acquire pulse Doppler imaging data based on initial imaging parameters; when the data volume exceeds a preset data volume threshold, adjusting initial imaging parameters so that the data volume to be acquired does not exceed the preset data volume threshold when pulse Doppler imaging is carried out according to the adjusted imaging parameters, and controlling an ultrasonic probe to acquire pulse Doppler imaging data based on the adjusted imaging parameters; the control memory stores acquired pulse Doppler imaging data, and the pulse Doppler imaging data is used for pulse Doppler offline analysis.

In an embodiment of the present application, the initial imaging parameters include default imaging parameters and settable imaging parameters, wherein the processor 630 adjusts the initial imaging parameters, which may include: the default imaging parameters are preferentially adjusted.

In an embodiment of the present application, the processor 630 obtains settable imaging parameters from the initial imaging parameters, which may include: acquiring at least one settable imaging parameter based on user input; and/or acquiring at least one settable imaging parameter based on an automatic identification of a color doppler flow image or a tissue doppler image.

In an embodiment of the present application, the settable imaging parameter acquired based on the user input is an unadjustable parameter.

In an embodiment of the application, the settable imaging parameters include at least one of the following: one or more regions of interest for pulsed doppler imaging, acquisition duration, pulse repetition frequency, maximum measurement speed.

In an embodiment of the application, the region of interest is a raw region of interest for color doppler flow imaging or tissue doppler imaging, or is one or more sub-regions within the raw region of interest.

In an embodiment of the application, the default imaging parameters include scan line density and/or downsampling rate.

In an embodiment of the present application, the processor 630 controls the memory 640 to store acquired pulse Doppler imaging data, including: storing all data of the acquired pulse Doppler imaging data into a memory 640, wherein all data are used for pulse Doppler offline analysis; or based on user input, store part of the acquired pulse doppler imaging data to memory 640, part of the data being used for pulse doppler offline analysis.

In an embodiment of the present application, the comparing the data amount with the preset data amount threshold value performed by the processor 630 may include: and acquiring a preset data quantity threshold value to be compared from a plurality of preset data quantity threshold values based on user input, and comparing the data quantity with the preset data quantity threshold value to be compared.

In an embodiment of the present application, the processor 630 may also be configured to: acquiring stored pulse Doppler imaging data, generating and displaying a pulse Doppler image by a display based on the pulse Doppler imaging data; and acquiring one or more sampling gates on the pulse Doppler image based on user input, and outputting an offline analysis result corresponding to an image area in the sampling gates to a display for display.

In another embodiment of the present application, the processor 630 may perform the following operations: acquiring a color Doppler blood flow image or a tissue Doppler image of a target object; acquiring a region of interest for pulse Doppler imaging of a color Doppler blood flow image or a tissue Doppler image; controlling an ultrasonic probe to acquire pulse Doppler imaging data of a region of interest; and outputting part of data in the acquired pulse Doppler imaging data to a memory 640 for storage, wherein the part of data is used for pulse Doppler offline analysis, and the part of data corresponds to pulse Doppler imaging data corresponding to one or more subareas in the region of interest.

In an embodiment of the application, the portion of the data is determined by processor 630 based on user input and/or automatic identification of pulse Doppler imaging data.

In an embodiment of the present application, the processor 630 determines partial data based on user input, may include: selecting one or more sub-regions in a region of interest for pulsed Doppler imaging based on user input; partial data corresponding to one or more sub-regions is determined from the pulsed Doppler imaging data.

In an embodiment of the present application, processor 630 determines partial data based on automatic identification of pulsed Doppler imaging data, which may include: automatically identifying the pulse Doppler imaging data, and determining one or more subareas according to the identification result; partial data corresponding to one or more sub-regions in the pulsed Doppler imaging data is determined.

In an embodiment of the present application, the user input described above may be obtained by the processor 630 through a user interaction device, for example, an interactive display screen of the ultrasound imaging device 600, or may also be a user interaction device such as a keyboard, a mouse, and the like.

Based on the above description, the ultrasound imaging apparatus 600 according to the embodiment of the present application calculates, before PW imaging is performed, whether the amount of data to be acquired when PW imaging is performed with the initial imaging parameters exceeds the preset data amount threshold, if not, acquires PW imaging data in real time with the initial imaging parameters, if so, adjusts the imaging parameters so that the amount of data to be acquired when PW imaging is performed with the adjusted imaging parameters does not exceed the preset data amount threshold, acquires PW imaging data in real time, and acquires the acquired data for offline PW analysis, so that the amount of data for offline analysis can be limited to an acceptable range in any clinical scenario. In addition, when the imaging parameters are adjusted, default imaging parameters can be preferentially adjusted, and settable imaging parameters set by a user are little adjusted or not adjusted, so that the method not only meets the index requirements of spectrum analysis (ensures the feasibility and certain flexibility of spectrum analysis) of a clinician in any clinical application scene, but also controls the original data volume within the allowable range of the system. Or the ultrasound imaging apparatus 600 according to the embodiment of the present application stores only a portion of PW imaging data after PW imaging, which corresponds to PW imaging data in one or more sub-regions in a region of interest for PW imaging, it can be achieved that the amount of data for offline analysis is limited to an acceptable range in any clinical scenario. In addition, since the accurate PW imaging data of the subarea for offline analysis is stored before offline analysis, the area with less analysis requirement can not be seen any more during offline analysis, so that the offline analysis is more targeted, and the efficiency of the offline analysis is improved.

Furthermore, according to an embodiment of the present application, there is also provided a storage medium having stored thereon program instructions for performing the respective steps of the pulse doppler ultrasound imaging method of an embodiment of the present application when the program instructions are executed by a computer or processor. The storage medium may include, for example, a memory card of a smart phone, a memory component of a tablet computer, a hard disk of a personal computer, read-only memory (ROM), erasable programmable read-only memory (EPROM), portable compact disc read-only memory (CD-ROM), USB memory, or any combination of the foregoing storage media. The computer-readable storage medium may be any combination of one or more computer-readable storage media.

Furthermore, according to an embodiment of the present application, there is also provided a computer program, which may be stored on a cloud or local storage medium. Which when executed by a computer or processor is adapted to carry out the corresponding steps of the pulse doppler ultrasound imaging method of an embodiment of the present application.

Based on the above description, the pulse doppler ultrasound imaging method and the ultrasound imaging apparatus according to the embodiments of the present application can achieve that the amount of data for offline analysis is limited to an acceptable range in any clinical scenario.

Although the illustrative embodiments have been described herein with reference to the accompanying drawings, it is to be understood that the above illustrative embodiments are merely illustrative and are not intended to limit the scope of the present invention thereto. Various changes and modifications may be made therein by one of ordinary skill in the art without departing from the scope and spirit of the invention. All such changes and modifications are intended to be included within the scope of the present invention as set forth in the appended claims.

Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the solution. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.

In the several embodiments provided by the present invention, it should be understood that the disclosed apparatus and method may be implemented in other ways. For example, the above-described device embodiments are merely illustrative, e.g., the division of elements is merely a logical function division, and there may be additional divisions of actual implementation, e.g., multiple elements or components may be combined or integrated into another device, or some features may be omitted, or not performed.

In the description provided herein, numerous specific details are set forth. However, it is understood that embodiments of the invention may be practiced without these specific details. In some instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description.

Similarly, it should be appreciated that in order to streamline the invention and aid in understanding one or more of the various inventive aspects, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof in the description of exemplary embodiments of the invention. However, the method of the present invention should not be construed as reflecting the following intent: i.e., the claimed invention requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single disclosed embodiment. Thus, the claims following the detailed description are hereby expressly incorporated into this detailed description, with each claim standing on its own as a separate embodiment of this invention.

It will be understood by those skilled in the art that all of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and all of the processes or units of any method or apparatus so disclosed, may be combined in any combination, except combinations where the features are mutually exclusive. Each feature disclosed in this specification (including any accompanying claims, abstract and drawings), may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise.

Furthermore, those skilled in the art will appreciate that while some embodiments herein include some features but not others included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the invention and form different embodiments. For example, in the claims, any of the claimed embodiments may be used in any combination.

Various component embodiments of the invention may be implemented in hardware, or in software modules running on one or more processors, or in a combination thereof. Those skilled in the art will appreciate that some or all of the functions of some of the modules in an item analysis device according to embodiments of the present invention may be implemented in practice using a microprocessor or Digital Signal Processor (DSP). The present invention can also be implemented as an apparatus program (e.g., a computer program and a computer program product) for performing a portion or all of the methods described herein. Such a program embodying the present invention may be stored on a computer readable medium, or may have the form of one or more signals. Such signals may be downloaded from an internet website, provided on a carrier signal, or provided in any other form.

It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word "comprising" does not exclude the presence of elements or steps not listed in a claim. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The invention may be implemented by means of hardware comprising several distinct elements, and by means of a suitably programmed computer. In the unit claims enumerating several means, several of these means may be embodied by one and the same item of hardware. The use of the words first, second, third, etc. do not denote any order. These words may be interpreted as names.

The above description is merely illustrative of the embodiments of the present invention and the protection scope of the present invention is not limited thereto, and any person skilled in the art can easily think about changes or substitutions within the technical scope of the present invention, and the changes or substitutions are covered by the protection scope of the present invention. The protection scope of the invention is subject to the protection scope of the claims.

Claims

1. A pulsed doppler ultrasound imaging method, the method comprising:

Acquiring a color Doppler blood flow image or a tissue Doppler image of a target object;

acquiring initial imaging parameters for pulse Doppler imaging of the color Doppler blood flow image or tissue Doppler image;

Calculating the data volume to be acquired when pulse Doppler imaging is carried out by using the initial imaging parameters, and comparing the data volume with a preset data volume threshold;

when the data quantity does not exceed the preset data quantity threshold value, controlling an ultrasonic probe to acquire pulse Doppler imaging data based on the initial imaging parameters;

When the data volume exceeds the preset data volume threshold, adjusting the initial imaging parameters so that the data volume to be acquired does not exceed the preset data volume threshold when pulse Doppler imaging is performed by the adjusted imaging parameters, and controlling an ultrasonic probe to acquire pulse Doppler imaging data based on the adjusted imaging parameters;

And storing the acquired pulse Doppler imaging data, wherein the pulse Doppler imaging data are used for pulse Doppler offline analysis.

2. The method of claim 1, wherein the initial imaging parameters comprise default imaging parameters and settable imaging parameters, wherein the adjusting the initial imaging parameters comprises: the default imaging parameters are preferentially adjusted.

3. The method of claim 2, wherein obtaining the settable imaging parameter of the initial imaging parameters comprises:

acquiring at least one of the settable imaging parameters based on user input; and/or the number of the groups of groups,

At least one of the settable imaging parameters is acquired based on an automatic identification of the color doppler flow image or tissue doppler image.

4. A method according to claim 3, wherein the settable imaging parameter obtained based on the user input is a non-adjustable parameter.

5. The method of claim 2, wherein the settable imaging parameter comprises at least one of: one or more regions of interest for pulsed doppler imaging, acquisition duration, pulse repetition frequency, maximum measurement speed.

6. The method of claim 5, wherein the region of interest is a raw region of interest for color doppler blood flow imaging or tissue doppler imaging, or is one or more sub-regions within the raw region of interest.

7. The method of claim 2, wherein the default imaging parameters include scan line density and/or downsampling rate.

8. The method of claim 1, wherein said storing the acquired pulsed doppler imaging data comprises:

storing all acquired pulse Doppler imaging data, wherein all data are used for pulse Doppler offline analysis; or alternatively

And storing part of data in the acquired pulse Doppler imaging data based on user input, wherein the part of data is used for pulse Doppler offline analysis.

9. The method of claim 1, wherein said comparing said data amount to a preset data amount threshold comprises:

And acquiring a preset data quantity threshold value to be compared from a plurality of preset data quantity threshold values based on user input, and comparing the data quantity with the preset data quantity threshold value to be compared.

10. The method according to claim 1, wherein the method further comprises:

displaying the stored color doppler flow image or tissue doppler image;

selecting one or more sampling gates within a region of interest of the color doppler flow image or tissue doppler image for performing the pulsed doppler imaging;

And acquiring data corresponding to the one or more sampling gates from the stored pulse Doppler imaging data, and generating and displaying pulse Doppler images corresponding to the one or more sampling gates based on the acquired data, wherein the pulse Doppler images corresponding to the one or more sampling gates are used for pulse Doppler offline analysis.

11. A pulsed doppler ultrasound imaging method, the method comprising:

Acquiring a region of interest for pulse doppler imaging of the color doppler blood flow image or tissue doppler image;

Controlling an ultrasonic probe to acquire pulse Doppler imaging data of the region of interest;

And storing part of data in the acquired pulse Doppler imaging data, wherein the part of data is used for pulse Doppler offline analysis, and the part of data corresponds to pulse Doppler imaging data corresponding to one or more subareas in the region of interest.

12. The method of claim 11, wherein the portion of data is determined based on user input and/or automatic identification of the pulsed doppler imaging data.

13. The method of claim 12, wherein determining the portion of data based on the user input comprises:

Selecting the one or more sub-regions in the region of interest based on user input;

The portion of data corresponding to the one or more sub-regions is determined from the pulsed Doppler imaging data.

14. The method of claim 12, wherein determining the portion of data based on automatic identification of the pulsed doppler imaging data comprises:

automatically identifying the pulse Doppler imaging data, and determining the one or more subareas according to an identification result;

The portion of the pulsed Doppler imaging data corresponding to the one or more sub-regions is determined.

15. The method of claim 11, wherein the method further comprises:

displaying the stored color doppler flow image or tissue doppler image;

16. An ultrasound imaging apparatus comprising transmit receive circuitry, an ultrasound probe, a processor, and a memory, wherein:

the transmitting and receiving circuit is used for controlling the ultrasonic probe to transmit ultrasonic waves to a target object, receiving echoes of the ultrasonic waves and acquiring ultrasonic echo data from the echoes;

The processor is configured to control the transmit receive circuitry and to perform the pulsed doppler ultrasound imaging method of any one of claims 1-15 to acquire pulsed doppler imaging data and to determine data to be stored for pulsed doppler offline analysis;

The memory is used for storing the data for pulse Doppler offline analysis.