METHOD AND SYSTEM FOR ULTRASONIC ACQUISITION AND PROCESSING

Abstract

Title: METHOD AND SYSTEM FOR ULTRASONIC ACQUISITION AND PROCESSING. Method for acquiring and processing ultrasonic waves in which the sequential processing comprises, for at least one of the elementary data blocks (Bi) of order i, a computer-implemented block processing (TBi) of order i, comprising, for at least one data subblock (SBij) of order j, an elementary processing comprising the combination of data from the data subblock (SBij) of order j so as to generate an elementary image, the block processing (TBi) of order i being implemented during the acquisition of order i+k with k greater than 0, i+k being less than or equal to N. Figure for the abstract: Fig. 4

Description

Title of the invention: METHOD AND SYSTEM FOR ULTRASOUND ACQUISITION AND PROCESSING Field of invention

[0001] The invention relates to ultrasound imaging.

[0002] It relates more particularly to a method for acquiring and processing ultrasonic waves for ultrasonic imaging.

[0003] The method is, for example, a method for super-resolution acquisition and processing of ultrasonic waves.

[0004] The resolution of conventional ultrasonic wave acquisition systems is limited by diffraction phenomena. Typically, the resolution is of the order of magnitude of the ultrasonic wavelength used by the acquisition system.

[0005] Super-resolution means a resolution higher than the maximum resolution achievable by a conventional ultrasonic wave acquisition system. This maximum resolution is equal to the diffraction limit of the acquired ultrasonic waves.

[0006] Consequently, super-resolution ultrasound images are understood to mean images having a resolution finer than the diffraction limit of the ultrasound waves used during the acquisition of the ultrasound waves used to generate the images. Typically, the generated images have a resolution improved by a factor of between 2 and 20 compared to this diffraction limit.

[0007] Super-resolution ultrasound imaging is conventionally based on the injection, into the blood, of ultrasound contrast agents in the form of millions of gas microbubbles which are detected, located and tracked on successive images so as to generate a reconstructed image of the imaged vessels.

[0008] In the literature, the Anglo-Saxon terminologies Ultrasound Localization Microscopy or ULM as well as all its variations, for example ultrafast ULM or uULM; transcranial ULM or tULM; sensing ULM or sULM; deep ULM or dULM; Super Resolution UltraSound SR-US; Super Resolution Microvascular Imaging or SR-MI; are ultrasonic super resolution methods having in common the use of ultrasound contrast agents, a step of detecting the signals coming from these contrast agents, and a step of reconstructing a super-resolved ultrasound image. State of the art

[0009] Generating super-resolution ultrasound images comprises repeating an acquisition sequence by an acquisition device using an ultrasound probe to generate successive data blocks. Each data block is generated during an acquisition sequence.

[0010] Each acquisition sequence comprises the repetition, a large number of times, of an elementary acquisition sequence. Each elementary acquisition sequence makes it possible to generate a sub-block of data. Each data block is therefore composed of several sub-blocks of data.

[0011] Each block of data is stored in a buffer memory of an acquisition device and then transmitted to an internal memory of a processing device before the acquisition of the next block of data. Since the speed of transfer and writing to the internal memory of the computer is limited, this operation can take several hundred milliseconds to several seconds in the case of 3D data which is very large.

[0012] Once the acquisition of all the data blocks is complete, the data blocks are processed block by block by a processing device. This processing begins by loading the data from the internal memory into the computer's RAM, known as Random Access Memory. Then, the data is sent from the RAM to the RAM of a graphics processing unit or GPU, to perform the steps of forming channels and eliminating echoes from the tissues. The data is then transferred to the computer's RAM where steps of detecting, localizing and temporally tracking the microbubbles are performed.

[0013] The method then comprises a step of reconstructing a super-resolution image. This step consists of accumulating the results of the tracking obtained for each block and for the different blocks.

[0014] Processing a block of data can take several seconds to several minutes in the case of 3D data that is very large.

[0015] This method has a number of drawbacks. Indeed, the acquisition of a new block of data must be stopped while the data is written to the internal memory of the processing device, which adds downtime to the acquisition. Furthermore, the results of the data processing are only available after the acquisition of all the blocks of data, once the data processing has started. Finally, large quantities of raw data (10 Gb - 1000 Gb) must be retained by the processing device for the entire duration of the acquisition and during part of the processing, which can lead to saturation of the RAM. Finally, additional transfer times are introduced during the processing, making it particularly long (>1 h).

[0016] One aim of the invention is to limit at least one of the aforementioned drawbacks.

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[0023] Summary of the invention For this purpose, the subject of the invention is a method for acquiring and processing ultrasonic waves comprising the sequential acquisition of N elementary data blocks of order i, with i = 1 to N, and the sequential processing, implemented by computer, of the elementary data blocks, the order i of each raw elementary data block being the acquisition order number of the data block among the N data blocks, the sequential acquisition comprising, for each elementary data block, the acquisition of the data block of order i comprising J acquisition(s) of sub-block(s) of data of order j, for j = 1 to J with J an integer greater than or equal to 1, comprising, for each transmission / reception configuration of a set of at least one transmission / reception configuration defined by a transmission sub-aperture and a reception sub-aperture of a transducer array,a set of at least one individual acquisition sequence comprising: - emission of an ultrasound beam, by the emission sub-aperture, in an area of ​​interest of a patient, , - reception of echoes by the reception sub-aperture, of echoes generated by the area of ​​interest under the effect of the ultrasonic beam, so as to generate electrical signals, - pre-processing including the digitization of signals from electrical signals in order to generate a set of elementary data, the sequential processing comprising, for at least one of the elementary data blocks of order i, a processing of block of order i, implemented by computer, comprising, for at least one sub-block of data of order j, an elementary processing comprising the combination of data of the sub-block of data of order j so as to generate an elementary image, the block processing of order i being implemented during the acquisition of order i+kO, kO being an integer greater than 0, i+kO being less than or equal to N. According to one embodiment, the i-order block processing is implemented during the acquisition of the i+1 order data block. According to one embodiment, the processing of block of order i is implemented only during the acquisition of the data block of order i+kO. According to one embodiment, the method comprises, during the acquisition of the data block of order i+kO, providing to a user, via a user interface, information from data generated during the processing of the block of order i. According to one embodiment, the elemental processing comprises enhancing signals from contrast agents on the elemental image relative to other signals so as to obtain an enhanced elemental image.

[0024] According to one embodiment, the elementary processing comprises the detection of contrast agent signals on the elementary image or on an image originating from the elementary image so as to obtain a set of contrast agent positions.

[0025] According to one embodiment, the i-order block processing comprises the tracking of contrast agents on several elementary images or images originating from elementary images.

[0026] According to one embodiment, the processing of block of order i comprises elementary processing operations implemented for respective sub-blocks of data, in parallel.

[0027] According to one embodiment, the individual acquisition sequence comprises the storage of the set of elementary data in a first memory, the method comprising the transfer of the block of elementary data of order i to a second memory, implemented, at least in part, prior to the block processing.

[0028] According to one embodiment, the first memory and the second memory are random access memories, the block of elementary data being transmitted from the first memory to the second memory without passing through another memory.

[0029] The invention also relates to a system for acquiring and processing ultrasonic waves, configured to implement the method according to the invention.

[0030] Advantageously, the acquisition system comprises the hardware and software means configured to implement the method according to the invention.

[0031] Advantageously, the acquisition and processing system comprising: - an acquisition system comprising the transducer network and configured to implement the acquisition step, - a processing system configured to implement the sequential processing step.

[0032] According to one embodiment, the acquisition system comprises the first memory and the processing system is intended to be connected in communication with the acquisition system, the processing system comprising the second memory.

[0033] The invention also relates to a computer program product comprising instructions which cause the system according to the invention to execute the steps of the method according to the invention.

[0034] The invention also relates to a computer-readable medium on which the computer program is recorded. Brief description of the figures

[0035] Other characteristics and advantages of the invention will emerge on reading the detailed description which follows, with reference to the appended figures, which illustrate:

[0036] [Fig-1]: an individual acquisition sequence,

[0037] [Fig.2]: an acquisition step of the method according to the invention,

[0038] [Fig.3]: a step of acquiring a sub-block of data,

[0039] [Fig.4]: an example of the temporal arrangement of the steps of acquisition and processing of a block of data of the method according to the invention,

[0040] [Fig.5]: an example of a processing step of the method according to the invention,

[0041] [Fig.6]: in block form, the hardware elements of an example system configured to implement the method according to the invention. Description of the invention

[0042] The invention relates to a method for acquiring and processing ultrasonic waves. This method is, for example, intended for super-resolution imaging. This method is advantageously, but not necessarily, a super-resolution imaging method. The invention also relates to the acquisition and processing system configured to implement the method.

[0043] Advantageously, the acquisition and processing system comprises the hardware and software means configured to implement the method.

[0044] This method is advantageously, but not necessarily, implemented after a step of intravenous injection into an individual of a contrast product comprising individual contrast agents, for example, in the form of gas microbubbles. These contrast agents injected into the body are of the exogenous type.

[0045] Alternatively, the method is carried out without an injection step of this type having been carried out beforehand, using endogenous contrast agents, for example red blood cells.

[0046] The method comprises sequentially acquiring and processing ultrasonic waves of N blocks of raw ultrasonic data B; with i = 1 to N where N is the number of blocks of raw ultrasonic data B; acquired and processed. Acquisition

[0047] The method comprises a step of sequential acquisition A of the blocks of raw ultrasonic data B;.

[0048] This step is implemented by an acquisition system SA comprising a probe S comprising a network R of transducers TR referenced in [Fig.6]. It is possible to define sub-apertures of the network R, each sub-aperture being composed of one or more transducers TR of the network R.

[0049] As visible in [Fig.l], we define a transmission sub-aperture SOo and a reception sub-aperture SOo' which define a transmission / reception configuration Ch is characterized by a pair (SOo, SOo'). The reception sub-aperture SOo' can be different or identical to the transmission sub-aperture SOo. The pairs of sub-apertures of different configurations Ch are different.

[0050] In the non-limiting example of [Fig.l], the transmission sub-aperture SOo is the reception sub-aperture SOo'.

[0051] The acquisition of a block of ultrasonic data B; comprises the repetition, preferably a large number of times, of an individual acquisition sequence sihk comprising the following steps shown in [Fig.l]: - Emission Ehk of an ultrasonic beam Wk by the emission sub-aperture SOo of the network R of transducers TR (referenced in [Fig.6]), - Reception R^ of echoes emitted by the surrounding environment under the effect of the ultrasonic beam Wk by the reception sub-aperture SOo' of the network R of transducers TR so as to generate electrical signals, - PTkh preprocessing, implemented by computer, by the acquisition system, comprising the digitization of the electrical signals so as to generate a set of elementary data RFijhk, and possibly (but not necessarily) one or more other operations carried out on the echoes received, such as a filtering step and / or a demodulation step (carrier suppression) and / or a time gain compensation step better known as TGC in reference to the Anglo-Saxon expression “Time Gain Compensation” and / or resampling of the digitized signals.

[0052] The received echoes are represented, in [Fig.l], in the form of a plurality of time signals corresponding to the evolution, over time, of the signal received by each of the transducers of the reception sub-aperture SOo'.

[0053] The elementary data set RFijhk is represented, in [Fig.l], in the form of a table in [Fig.l]. It comprises a time sampling of the signal received by each of the transducers of the receiving sub-aperture. Each box corresponds to a time sample of one of the transducers of the receiving sub-aperture. The box comprising the black circle corresponds to the time sample marked by a black circle.

[0054] Advantageously, the individual acquisition sequence sihk comprises a step of storing MEMhk the set of elementary data RFijhk in a first memory.

[0055] Each individual sequence si^ is advantageously carried out so that the ultrasound beam emitted during the reception step insonifies the area of ​​interest of the individual containing the contrast agents, for example, in the form of microbubbles and so as to receive, during the reception step, echoes coming from the area of ​​interest. Thus, the raw ultrasound data comes from a region of interest of a patient comprising contrast agents during the acquisition step.

[0056] Alternatively, the contrast agents are endogenous. In the case of vascular ultrasound, red blood cells can, for example, be used.

[0057] Advantageously, the area of ​​interest is an area of ​​the patient comprising vessels blood in which endogenous or exogenous contrast agents are present at the time of the acquisition phase.

[0058] Advantageously, the circulating contrast agents move relative to the area of ​​interest.

[0059] In the case where the area of ​​interest comprises blood vessels, the contrast agents advantageously move in the blood vessels under the effect of the circulation of blood in the vessels.

[0060] In the remainder of the text, we consider the case of a non-limiting example in which the acquisition concerns an area comprising contrast agents in the form of microbubbles. The steps described below which relate to these microbubbles are valid for other types of contrast agents.

[0061] As shown in [Fig.2], the acquisition step A comprises an elementary acquisition sequence seh, during which K individual acquisition sequences sihk are implemented, where K is an integer greater than or equal to 1, using the same transmission / reception configuration Ch so as to acquire K elementary data sets RFÿhk.

[0062] The individual acquisition sequences sihk differ from each other in that the ultrasonic beams Wk have distinct spatial and / or temporal (frequency) characteristics. For example, in one embodiment, the K ultrasonic beams may be a family of plane waves emitted with different angles relative to the grating R. Another embodiment consists of sending K beams corresponding to waves having respective amplitudes differing from each other by predetermined scalar factors.

[0063] The method comprises a step sbj of acquiring a data sub-block SBÿ which comprises the implementation of H elementary acquisition steps seh with h= 1 to H, where H is an integer greater than or equal to 1, carried out with respective distinct transmission / reception configurations Ch.

[0064] The elementary acquisition step A; of a data block B; comprises the implementation of the acquisition step sbj of a data sub-block SBÿ. This step is implemented J times so as to acquire J data sub-blocks SBÿ.

[0065] J is an integer greater than or equal to 1. Typically, J is between 1 and 2000. Advantageously, J may be the same for each data block B; but data blocks B; may, alternatively, have distinct J.

[0066] The data sub-blocks SBÿ are acquired successively in the temporal order defined by the index j representing the jth implementation of the step of acquiring a sub-block denoted sbj.

[0067] When the step sbj of acquiring a sub-block of data SBÿ has been implemented, that is to say when the elementary acquisition sequences seh have been implemented for the different transmission / reception configurations Ch (with h = 1 to H), we obtain a sub-block of elementary data SBÿ composed of H*K elementary data sets RFijhk, as represented in [Fig.3].

[0068] The sequential acquisition step A of the N raw data blocks B; comprises the implementation of the elementary acquisition step A; to acquire a block of ultrasonic data B; of order i. The elementary acquisition step A; is implemented N successive times so as to acquire the N data blocks B;. The data blocks B; are acquired successively in the temporal order defined by the index i representing the ith implementation of the elementary acquisition step A;.

[0069] N is an integer greater than 1. N is advantageously determined so that N*J*H*K is between 1000 and 10,000,000. In a typical embodiment, N = 300, J = 1000, H = 4 and K = 5, i.e. N*J*H*K = 6,000,000.

[0070] In order to generate a number equal to N blocks of data B;, the step of acquiring A; a block of raw data B; is repeated Nl times. A set denoted B is thus obtained, such that B = {Bb ..., B;, ..., BN] of blocks of raw data B;. Step A; of index i corresponds to the implementation, for the ith time, of the step of acquiring A; a block of raw data and makes it possible to acquire the block of data B; of order i.

[0071] In [Fig. 3], two transmission / reception configurations Ci and C4 of the ultrasonic probe S are shown. The configuration Ci is characterized by an emission sub-aperture SOi which is also the reception sub-aperture of this same configuration Cp. The configuration C4 is characterized by an emission sub-aperture SO 4 which is also the reception sub-aperture of this same configuration C4.

[0072] Also shown are the transmission steps Ehk of the individual acquisition sequences siik and si4k (with k = 1 to 5) implemented during elementary acquisition sequences seiet se4 using the respective transmission / reception configurations Ci and C4 as well as the elementary data sets RFijhk generated during these elementary acquisition sequences.

[0073] In [Fig.4], the different steps implemented during the acquisition and processing of two consecutively acquired data blocks B; and Bi+i are shown in the temporal order represented by the time axis t.

[0074] Each raw data block B; comprises a number J of data sub-blocks SBÿ with j = 1 to J, where J is an integer greater than or equal to 1, acquired during the J respective implementations of the step sbj of acquiring a data sub-block SBÿ.

[0075] As visible in [Fig.4], the data of the raw data block B; are stored, during a storage step m;. This step is advantageously implemented during the acquisition step Ai of the data block B; of order i, for the generation of the data block B; of order i.

[0076] In a particular embodiment of the invention, this storage step m; includes the MEMhk storage steps implemented during step Ai of acquiring data block B;. Sequential processing

[0077] The method according to the invention comprises a step of sequential processing of the data blocks B; implemented by computer, by a processing system, for example, a processing device DT, as we will see in the rest of the text.

[0078] The sequential processing step comprises, for at least one data block B; and, preferably, for each data block B;, the implementation, by computer, of a step of processing block TB; of order i of the data block B;, called block processing TB; of the data block of order i or block processing TB; of order i or block processing in the rest of the text.

[0079] According to the invention, as represented in [Fig.4], the processing of block TB; of a data block B; of order i less than N is implemented during the acquisition step A i+ko of the data block Bi+k0 of order i+kO with kO integer greater than or equal to 1, i+kO being less than or equal to N.

[0080] In other words, the block processing step TB; of a data block B; of order i less than N is implemented at least in part during the acquisition step Ai+k0 of the data block Bi+k0 of order i+kO with kO being an integer greater than or equal to 1, i+kO being less than or equal to N.

[0081] In the non-limiting example of [Fig.4], kO is equal to 1 so that the block processing TB; of the data block B; of order i is implemented during the acquisition step Ai+i of the data block Bi+i. In other words, the block processing step TB; of the data block B; of order i is implemented during the acquisition Ai+i of the data block Bi+i of order i+1 acquired consecutively to the data block B; of order i.

[0082] The invention therefore consists in processing a data block B; of order i during a subsequent acquisition of another data block Bi+k0, for example, during the acquisition of the following block, i.e. of order i+1. An advantage is to limit, or even eliminate, dead times during the acquisition.

[0083] Furthermore, once the block processing of a block of data has been carried out, the data resulting from this block processing can be transferred to a display device to provide real-time visual feedback to the user. The method therefore makes it possible to limit the downtime before the display of data generated from the acquired raw data.

[0084] Thus, according to a particular embodiment, the block processing step TB; comprises, during the acquisition Ai+k0 of the data block Bi+k0 of order i+k0, the display AFF;, on a display of an output interface INTS of a human-machine interface INT, referenced in [Fig.6], of a representation of information from data generated during the block processing TB; of order i.

[0085] Finally, the method according to the invention makes it possible, if necessary, to erase, that is to say to delete, the raw data of the raw data blocks B; as and when required after the implementation of the respective block processing operations TB;. This makes it possible to further reduce the costs in terms of duration and memory.

[0086] When the processing of block TB; comprises a step of locating or tracking positions of the microbubbles on images generated from the sub-blocks of data of block B;, the data obtained are very small in volume since they consist of successive positions of the different microbubbles. These data can be transferred to an internal memory, that is to say a read-only memory, of the processing system, for example of the processing device, such as a microcomputer, without impacting or slowing down the rest of the method.

[0087] The implementation of the block processing TB; of a data block B; of order i less than N during the acquisition Ai+k0 of the data block Bi+k0 of order i+kO with kO integer greater than or equal to 1, i+kO being less than or equal to N, can be carried out for one or more data blocks of different orders i, for example for any i less than or equal to N-kO. This applies to all the embodiments previously described and described below.

[0088] Thus, in the case of an implementation for any i less than or equal to N-kO, this means that the processing of each data block of data B; of order i less than N-kO is implemented during the acquisition Ai+k0 of the data block Bi+k0 of order i+kO with kO integer greater than or equal to 1, i+kO being less than or equal to N. This makes it possible to improve the advantages of the invention.

[0089] Advantageously, for at least one i, the processing of block TB; of the data block B; of order i begins during the acquisition Ai+k0 of the data block Bi+k0 of order i+kO and ends during the acquisition of the data block Bi+i of order i+l with 1 less than or equal to Ni. Thus the processing of the block of order i is finished before the acquisition of the data block of order i+1. This makes it possible to make the data generated during the block processing available more quickly and to limit the memory space to the conservation of the data from the acquisition of the block i.

[0090] In the particular embodiment of [Fig.4], kO = 1. This makes it possible to limit as much as possible the delay between the acquisition of the data and the start of data processing.

[0091] In the particular embodiment of [Fig.4], the block processing TB; of the data block B; of order i begins during the acquisition Ai+i of the data block Bi+i of order i+1 and is shorter than the acquisition Ai+i of the data block Bi+i of order i+1. In other words, the block processing TB; of the data block B; of order i is implemented only during the acquisition Ai+i of the data block Bi+i. This makes it possible to limit as much as possible the time taken to generate the final results of the block processing TB; and therefore their display time, or more generally their availability to a user. This also provides the possibility of limiting as much as possible the latency time between the end of the Bi+i acquisition of a data block of order i+1 and the processing of the Bi+i data block of order i+1, because the processing of the data block of order i is finished. The display makes it possible to provide the user with a means of feedback on the acquisition, in particular to help them maintain stable positioning.

[0092] Advantageously, for any i less than or equal to N-kO, the processing of block TB; of the data block B; of order i begins during the acquisition Ai+k0 of the data block Bi+k0 of order i+kO and ends during the acquisition of the data block Bi+k0 of order i+kO. Thus, the processing of the data block B; of order i is completed before the acquisition of the data block of order i+kO. An advantage is that it makes it possible to provide the user with data obtained during the acquisition of the different data blocks. This makes it possible, for example, to reconstruct the final image as it progresses and therefore to follow its evolution during the acquisition of the data.

[0093] Alternatively, for at least one i or for any i such that i+kO less than or equal to N, the processing of the data block B; of order i which begins during the acquisition of the block Bi+ko of order i+kO, ends after the acquisition of the data block Bi+k0 of order i+kO.

[0094] The block processing steps are implemented in the order defined by the order of acquisition of the data blocks of order i or not. Block processing

[0095] In [Fig.5], a flowchart of the steps of an example of processing T is shown, comprising the implementation, for each block B;, of data of order i, of a block processing step TB; corresponding to a super-resolution processing step.

[0096] The block processing step TB; comprises for each data sub-block SBÿ, an elementary processing TBÿ comprising the steps listed below, implemented by computer: - Combine COMB of data from the data sub-block SBÿ, to generate an elementary image IEÿ, - Improve AM the signals coming from the microbubbles, so as to generate an improved elementary image IAÿ from the elementary image IEÿ, - Detect DE microbubbles on the improved elementary image IA;i so as to obtain a set of Pijm positions of MIym microbubbles detected on the improved elementary image IA;i, - Localize LO the detected microbubbles so as to generate a set of sub-pixel or sub-voxel positions of microbubbles PSijm with m= 1 to M with M integer greater than or equal to 0.

[0097] The elementary processing steps TBÿ for a given i are implemented in the temporal order defined by the orders j of acquisition of the elementary data sub-blocks SBÿ or in another temporal order.

[0098] The COMB combination step allows you to move from the space of times to the space of distances. The elementary image is, for example, two-dimensional or three-dimensional.

[0099] By elementary image IEÿ, we mean a mesh of pixels or voxels whose respective intensities are representative of acoustic properties of the environment surrounding the probe in respective coordinates. The coordinates of a pixel or a voxel represent a position relative to the probe of a point in the surrounding environment.

[0100] The processing of block TB; of the data block B; of order i then comprises a step of temporal tracking SU of the microbubbles MIijm on the different improved elementary images IAÿ (with j = 1 = J) generated for the data block B; or on at least a part of these improved elementary images so as to obtain sets of positions of the contrast agents, for example microbubbles.

[0101] For example, assuming that we track microbubbles on all the enhanced elementary images IAÿ (with j = 1 = J) and that no microbubbles disappear, we obtain J positions PSÿm for each of the M microbubbles Mim detected.

[0102] It should be noted that the LO localization step is optional. The tracking step may consist of tracking the Pijm positions of the microbubbles obtained during the DE detection step instead of tracking the more precise PSijm positions obtained during the LO localization step.

[0103] The block processing step TB; can then comprise a step RE of reconstructing an image from data generated during block processing TB; of the data block B; of order i.

[0104] For example, the reconstruction step RE comprises a step of reconstructing an IR image; representing the paths followed by different microbubbles on the different improved elementary images AMÿ generated from the respective data sub-blocks SBÿ of the data blocks of order i B;, i.e. representing the positions Pijm or PSijm of the microbubbles followed on the respective data sub-blocks SBÿ.

[0105] The processing step T can then comprise a step of global reconstruction REG of a global image IG from data generated during processing of block TB; of order i of the data block B; of order i, for example, from IR images; reconstructed during reconstruction steps RE, for example from the IR images; with i = 1 to N.

[0106] The steps listed above are carried out by conventional methods known to those skilled in the art which will not be described again here. Non-limiting examples Examples of the methods used are given below.

[0107] The COMB combination step comprises, for example, a track formation step, called “beamforming” in English terminology.

[0108] In one embodiment, the channel formation step is carried out by the method called Delay and Sum, better known by the English name of “Delay & Sum”.

[0109] For example, in the case of 2D plane wave imaging where there is only one sub-aperture defined by transducers aligned along an axis of the probe. The different beams Wk are plane waves emitted with an angle ak relative to a normal direction. The elementary images IEÿ are obtained by combining a sum of the signals acquired by the transducers delayed by delays r(x, X, ): [0i 10] IE..U x) = Ya^RFljak(t(x, x ak)) [YES] Where J , \ zcose^+^sinaj- Jz-^x^x")' dx, X, ad =---T---- + J---

[0112] Where x is a coordinate of a point along the axis of the probe in a frame linked to the probe; z is a coordinate of a point along the normal to the axis of the probe in the frame linked to the probe and x' is a coordinate of the transducer along the axis of the probe in the frame linked to the probe.

[0113] The COMB combination step can be carried out by other methods known to those skilled in the art based on mathematical models, for example, by channel formation in Fourier space, using adaptive or multi-variant methods. It can alternatively be carried out by a learning method using, for example, a neural network trained to reconstruct the elementary images from the data of the sub-block.

[0114] In a particular embodiment, the elementary acquisition step seh comprises the implementation of several individual acquisition sequences sihk with k = 1 to K and K is an integer greater than 1. These individual acquisition sequences si^ differ in that spatial and / or temporal characteristics of the beams emitted during their respective emission steps E^ differ as explained previously.

[0115] The COMB combination step implemented during the elementary processing TBÿ comprises, for example, several channel formation steps, the respective channel formation steps use data acquired under the effect of the emission of respective beams, during the acquisition of the data sub-block SBÿ, so as to form several intermediate images and a combination step, for example averaging of these intermediate images so as to form the elementary image. This method is known by the English name of "compounding" or "coherent compounding". It makes it possible to increase the contrast and the resolution of the images. Combining multiple images reduces noise and therefore increases contrast. Combining images acquired using separate beams increases resolution.

[0116] Alternatively, K is equal to 1.

[0117] Alternatively and / or additionally, the step sbj of acquiring a sub-block SBÿ comprises the implementation of several elementary acquisition sequences seh with h = 1 to H and H is an integer greater than 1. These elementary acquisition sequences seh differ by the transmission / reception configurations Ch used. This type of method makes it possible to address probes with a greater number of transducers than the number of available electronic processing channels.

[0118] In this case, the COMB combination step advantageously comprises a known step of concatenating the acquired data with the different transmission / reception configurations so as to recompose the entire field of view. This step is implemented prior to the channel formation step(s).

[0119] The combination step comprises, for example, a step of concatenating the data acquired by means of the different elementary sequences.

[0120] Alternatively, H= 1.

[0121] The AM improvement step implemented to improve the signals of the elementary image IEÿ, which come from the microbubbles compared to other signals of the elementary image IEÿ, can use only the elementary image IEÿ or this image and at least one of the other elementary images IEÿ- with j' different from j. In other words, this step makes it possible to improve the contrast between these two types of signals.

[0122] This AM enhancement step consists, for example, in improving the signals from the microbubbles compared to those from the surrounding tissues, for example, the walls of the blood vessels in which the microbubbles circulate.

[0123] The AM enhancement step comprises, for example, a filtering step to remove signals from the tissues of the elementary image and to retain only the signals from the microbubbles. This step is, for example, known as a “clutter filter”. It comprises, for example, the application of spatio-temporal filters of the Singular Value Decomposition or SVD type, an acronym for the expression “Singular Value Decomposition” in English terminology, to separate the echoes from the microbubbles from the echoes from the tissues.

[0124] Alternatively, the AM enhancement step uses a non-linear strategy. This is, for example, a particular processing method based on the emission of particular beams during the acquisition step. The beam is, for example, defined so as to perform a phase inversion known as “Pulse Inversion” in English terminology, an amplitude modulation, for example a modulation amplitude on long ensembles (AMLE), a CHIRP emission (acronym for Compressed High Intensity Radar Puise), an emission using a Golay code, or other equivalent strategies.

[0125] The step of detecting microbubbles is, for example, implemented by searching for local maxima of the intensity of the pixels or voxels of the enhanced image. This step typically makes it possible to position the microbubbles to the nearest pixel or voxel.

[0126] The LO microbubbles localization step consists of improving the precision of the positions of the microbubbles obtained during the DE detection step. This is advantageously a localization method with sub-pixel or sub-voxel precision.

[0127] The LO localization step is, for example, carried out by weighted average of the intensity of the neighboring pixels / voxels, by interpolation, for example using a Gaussian, Cubic, Spline, or Lanczos kernel, by adjustment of a Gaussian function better known as "Gaussian fit", by an algorithm using the radial symmetry of the signal of an isolated microbubble, or more generally of an isolated contrast agent, and which makes it possible to explicitly calculate the position as the point minimizing the distance to the streamlines of the spatial gradient by or any other equivalent method. The interpolation and Gaussian adjustment methods are precise. The methods using a weighted average are precise.

[0128] The SU microbubbles tracking step, better known as "tracking" in English terminology, is for example implemented using the nearest neighbor method, which consists of assigning to each microbubble of the sub-block SBÿ, the microbubble of the sub-block SBij+i whose distance is closest; or by using the Kuhn Munkres algorithm also called the Hungarian method and which consists of minimizing the sum of the distances between all the microbubbles of the sub-block (i,j) and all the microbubbles of the sub-block (i,j+l). It is also possible to combine these approaches with Kalman filters to integrate a priori into these tracking methods.

[0129] The TB block processing can of course include other steps.

[0130] It may, for example, comprise a step of correcting the positions of the microbubbles which can be carried out in parallel with other steps of the TB block processing step; and comprising a step of estimating the movements (for example due to the patient's breathing) and a correction step using these movements to correct elementary images or improved images or directly the positions of the microbubbles calculated during the location step.

[0131] The block processing may include a step of correcting various aberrations due to the propagation of ultrasound through biological tissues, for example the skull or a layer of fat. These corrections may, for example, use the microbubbles to determine a general aberration law and use it to correct the delays when combining COMB.

[0132] The method may comprise a step of processing the trajectories of the microbubbles to correct spatial and temporal sampling artifacts.

[0133] The reconstruction steps RE and REG are, for example, carried out by accumulation.

[0134] For example, a mesh of the space is defined in voxels of predefined size, and the value of each voxel is incremented each time a contrast agent, for example a microbubble, is detected in this voxel during the monitoring steps of the TB block treatment; or during the monitoring steps of the first TB treatments; with i = 1 to N. thus creating a representation of the blood volume in the observation field. It is also possible for each voxel to represent the average speed of the microbubbles having crossed it.

[0135] Alternatively, the elementary processing TBÿ comprises part of the steps represented in [Fig.5]. It comprises, for example, the combination step COMB and possibly the improvement step and / or the detection step and / or the localization step LO and / or the tracking step SU and / or the reconstruction step RE.

[0136] Advantageously, the processing of block TB; of order i comprises, for example, instead of the detection, localization and tracking steps, following the implementation of the AM improvement step for each of the sub-blocks so as to obtain improved images IAÿ for j = 1 to J, a step of reconstructing an image, from the improved images IAÿ generated for the block of order i (i.e. for j = 1 to J), by a stochastic optical fluctuation imaging method better known under the name SOFI, acronym for the English expression "Stocastic Optical Fluctuation Imaging". An improved resolution of the root of 2 is obtained compared to the resolution of the improved images.

[0137] Alternatively, an ultrasensitive Doppler imaging method is known in which the reconstruction step RE consists of taking the temporal quadratic average of the improved images IAÿ obtained for the different sub-blocks of data SBÿ (with j = 1 to J) generated for a given i.

[0138] As a variant, the method comprises, following the implementation of the AM improvement step for each of the sub-blocks so as to obtain improved images IAÿ, a texture tracking step, better known as Speckle Tracking in English terminology, so as to obtain a sequence of images.

[0139] Alternatively, the block processing step TB; comprises the combination step COMB so as to obtain the images IEÿ. The reconstruction step RE is implemented by averaging all or part of the images IEÿ obtained for the different sub-blocks SBÿ so as to obtain an image better known as a B-mode image. Acquisition and processing system

[0140] In [Fig.6], a block diagram of the SYS system according to an exemplary embodiment of the invention configured to implement the method according to the invention is shown.

[0141] The system SYS comprises, for example, an acquisition system SA and a processing system which is a processing device DT in the non-limiting example of [Fig.6].

[0142] Alternatively, the processing system comprises different elements capable of communicating by wired or wireless communication means.

[0143] The acquisition system SA comprises a probe S and an acquisition device DA.

[0144] The probe S comprises the network R of transducers TR.

[0145] The TR transducer array can be one-dimensional. The TR transducers are then arranged in a line. The line is, for example, a straight line, the array is then linear, or curved. Alternatively, as in the example of [Fig.6], the TR transducers are arranged in lines and columns on a flat or curved surface. The TR transducers are advantageously regularly distributed in space. One variant consists of distributing the TR transducers randomly in space to form a sparse probe. Another variant consists of using probes called RCA for Raw-Column Arrays, where the elements of the same line and the same column are connected to each other.

[0146] The DA acquisition device comprises an EM transmitter, a CTR controller, a possible MUX multiplexer, a MPR pre-processing module comprising an analog-to-digital converter CAN, a first MT memory and a COL probe communication system.

[0147] The DA acquisition system is configured to implement the acquisition step A of the method according to the invention.

[0148] The MUX multiplexer allows the transmission and reception sub-openings to be selectively addressed.

[0149] When excited by the EM transmitter, via the MUX multiplexer, each transducer TR emits an ultrasonic pulse.

[0150] The CTR controller is capable of controlling the other elements of the DA acquisition device.

[0151] The controller CTR is configured to control, at each emission step Ehk: - the transmitter EM so that it generates, for the transducers TR, an excitation defined so that the emission sub-aperture SOo, receiving the excitation, emits an ultrasonic beam Wk defined by its temporal and spatial properties, - the multiplexer MUX so that the excitation is transmitted to the transducers of the emission sub-aperture SOo.

[0152] For example, the EM transmitter generates an excitation signal defining a waveform and a predetermined frequency of the wave and applies to this signal different delays so as to generate respective elementary excitation signals intended to excite the respective transducers TR of the emission sub-aperture SOo so as to define a direction of the beam Wk intended to be emitted by the sub-aperture SOo.

[0153] The controller CTR controls the configuration of switches of the multiplexer MUX so that the multiplexer transmits the respective elementary excitation signals to the respective transducers TR of the emission sub-aperture SOo so that the array of transducers TR emits the emission beam Wk.

[0154] The controller CTR is configured to control, at each reception step R^, the multiplexer MUX so that only the transducers TR of the reception sub-aperture SOo' transmit the electrical signals generated due to the emission of the ultrasonic beam Wk to the pre-processing device MPR.

[0155] The MPR pre-processing device may further comprise, by way of example, at least one filter and / or a demodulator and / or a time gain compensator and / or a sampler.

[0156] The controller CTR is programmed to control elements of the acquisition device DA so that the latter implements the acquisition step A.

[0157] In an exemplary embodiment, the CTR controller comprises, for example, a set of at least one processor operatively coupled to a memory in which is stored a program executed by the CTR controller so that the DA acquisition system implements the acquisition step A.

[0158] The multiplexer MUX transmits the signals received by the transducers TR of the receiving sub-aperture SOo' to the pre-processing device MPR comprising the analog-digital converter CAN to generate the digital raw data sets RFijhk from the echo signals. These data sets are recorded in the memory MT of the acquisition device ACQ during the storage step MEM^.

[0159] Advantageously, the first memory MT is a random access memory or RAM. It is, for example, a buffer memory of the acquisition device DA.

[0160] The DA acquisition device comprises a set of at least one COI communication system allowing the DA acquisition device to communicate with the probe S and with a set of at least one CO2 communication system of the DT processing device so as to allow the transmission of data from the MT memory of the ACQ acquisition device to the DT processing device, for example to a second MDT memory of the DT processing device.

[0161] The controller CTR is capable of controlling the communication system Cl of the acquisition device DA so that it transmits the data to the communication system CO2 of the processing device DT.

[0162] The processing system, for example the processing device DT, comprises the second memory MDT, a processing unit UT and a human-machine interface INT comprising an input interface INTE and an output interface INTS.

[0163] Advantageously, the method comprises, as visible in [Fig.4], prior to the block processing step TB;, a transfer step TRA; of the data block B; to the second memory MDT. One advantage is to empty the first memory MT and to allow the acquisition process to continue without saturating the first memory MT. Another advantage is to allow the size of the first memory MT to be limited.

[0164] In the particular example of [Fig.4], the processing of block TB;, of order i begins when the transfer step TRA; of the data block B; of order i is completed. Alternatively, the processing step of block TB; of order i begins during the transfer step TRAi of order i. In other words, the transfer step is carried out at least in part prior to the processing step of block TB;. The processing of block TB; can in fact begin as soon as a sub-block has been transferred from the first memory MT to the second memory MDT.

[0165] The TRA transfer step is, for example, carried out by the COI communication system under the effect of the command of the CTR controller.

[0166] The transfer step TRA; is, for example, implemented during the acquisition Ai+k0 of the data block Bi+k0 of order i+kO during which the block processing step TB; of the data block B; of order i is implemented or begins.

[0167] In the particular example of [Fig.4], kO = 1. The smaller kO, the smaller the size of the first MT memory can be.

[0168] This is valid for at least one i, for example for any i less than or equal to N-kO.

[0169] Advantageously, during the transfer step TRA;, the data block B; is erased of the first MT memory. The TRA transfer of data from the first MT memory to the second MDT memory makes it possible to record, in the first MT memory, data acquired during the acquisition of the data block Bi+k0.

[0170] Advantageously, the second memory MDT is a RAM of the processing device DT. One advantage is the speed of storage.

[0171] Advantageously, the data block B; is transmitted directly from the first memory to the second memory MDT without passing through another memory.

[0172] In a particular embodiment, the second MDT memory is a memory of a GPU.

[0173] The processing unit UT is configured to implement the processing step T or at least the block processing step TB; of the method according to the invention.

[0174] In an exemplary embodiment, the processing unit UT comprises, for example, a set of at least one processor operatively coupled to a memory in in which is stored a program executed by the processing unit UT so that the processing unit UT implements the processing step T.

[0175] The processing unit UT and / or the controller CTR are configured to synchronize the operations carried out by the acquisition system SA and the processing system so as to implement the method according to the invention.

[0176] The data generated during the processing of block TB; are advantageously stored in the second memory MDT.

[0177] This data can then be transferred to an internal memory of the DT processing system, for example the DT processing device.

[0178] The transfer of this data is advantageously carried out after the acquisition step A.

[0179] Alternatively, the data is directly stored in an internal memory of the processing device.

[0180] Advantageously, the processing device DT or processing system is configured to implement the display step AFF; and the processing unit UT is configured to generate the data to be displayed during this step.

[0181] This step consists of displaying a representation of information from data generated during the block processing step TB;. It can be implemented at the end of the block processing step TB; as in the example of [Fig.5] or at any other time during the block processing step, as soon as data has been generated.

[0182] This involves, for example, displaying one of the images IEÿ, IA,, of an IR image; constructed from Pijm positions generated from a sub-block of data or from several sub-blocks of data or from a table of values ​​of these positions, from an indicator or from a score.

[0183] If the displayed data are not data obtained during the steps COMB, AM, DE, LO, SU, the block processing step TB; advantageously comprises a step of calculating data to be displayed from data calculated during one of these steps to display the data to be displayed during the display step.

[0184] When the elementary processing TB;j comprises only a part of the steps COMB, AM, DE, LO, SU visible in [Fig.5], the processing unit UT is advantageously configured to control the transmission, via the system CO2, to a second processing unit of the processing system, for example, another processing device or a server, of data generated during the processing of block TB;. The second processing unit is advantageously configured to implement the remaining steps taken from COMB, AM, DE, LO, SU or at least one of these steps.

[0185] The reconstruction step RE can be implemented by the processing unit UT or a second processing unit. In the latter case, the processing unit UT is then advantageously configured to control the transmission, via the system C02, to the second treatment unit of the treatment system.

[0186] Advantageously, the elementary processing steps TB;j implemented, for j = 1 to J, during a block processing step T;, are implemented in parallel, i.e. simultaneously. This makes it possible to quickly process the data sub-block SBy.

[0187] The system, in particular the memories and the processing unit(s) and the communication systems are configured, in particular dimensioned, to enable the method according to the invention to be implemented. This configuration is, for example, carried out experimentally. Material

[0188] From a hardware point of view, the processing system and the CTR controller can be seen as computers interacting with computer programs.

[0189] The DT processing system and the DA acquisition device comprise at least one computer, for example, a microcomputer, a computer network, an electronic component, a tablet, a smartphone or a personal digital assistant (PDA).

[0190] The data processing unit UT, the possible second processing unit, and the controller CTR each comprise, for example, a computer, comprising a set of at least one processor, and possibly a memory operationally coupled to the computer.

[0191] The memory comprises, for example, a computer-readable medium. The computer-readable medium is a tangible device readable by a reader of the processing unit, capable of storing electronic instructions and of being coupled to the COI, CO2 communication system.

[0192] In other words, the computer-readable medium is a tangible medium. In other words, it is not a transient signal per se, such as radio waves or other freely propagating electromagnetic waves, such as light pulses or electronic signals. Such a computer-readable storage medium is, for example, an electronic storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any combination thereof.

[0193] For example, the readable medium is an optical disk, a magneto-optical disk, a read-only memory (ROM), an erasable and programmable read-only memory (EPROM), an electrically erasable and programmable read-only memory (EEPROM), a random access memory (RAM), a magnetic card or an optical card.

[0194] Each of the first memory MT and second memory MDT may be of one of the aforementioned types.

[0195] The readable medium may include an operating system and load the programs according to the invention. It includes registers adapted to record parameter variables created and modified during the execution of the aforementioned programs. A computer program comprising software instructions is then stored on the readable medium.

[0196] Alternatively, the program instructions come from an external source and are downloaded via a network. This is particularly the case for applications.

[0197] The data processing unit UT, the possible second processing unit and the controller CTR each comprise a calculator, i.e. at least one electronic data processing circuit designed to manipulate and / or transform data represented by electronic or physical quantities in registers of the evaluation system and / or memories into other similar data corresponding to physical data in the memories of registers or other types of display devices, transmission devices or storage devices.

[0198] The data processing unit UT and / or the optional second processing unit and / or the controller CTR comprise, for example, memories, for storing data, operatively coupled to the data processing circuit and a reader adapted to read a computer-readable medium.

[0199] The steps of the method according to the invention are, for example, executed by causing the processing circuits of the data processing unit UT, of the possible second processing unit, and of the controller CTR to read predetermined programs recorded on hardware such as memories so that their data processing circuits execute calculations, control communications and read and / or write data in memories.

[0200] The processing step is, for example, executed on a processing device, for example a single computer, or on a system distributed between several computers (in particular via the use of cloud computing).

[0201] The data processing unit UT, the possible second processing unit, and the controller CTR each comprise at least one computer comprising at least elements listed below: a set of one or more processors (for example at least one central processing unit (CPU) and / or at least one graphics processing unit (GPU) and / or at least one microcontroller and / or at least one digital signal processor (DSP)) capable of interpreting instructions in the form of a computer program and / or a hardware element, such as an electronic card, in which steps of the method according to the invention are implemented in hardware elements.

[0202] In a particular embodiment of the invention, the processing unit UT comprises a graphics processor GPU. Alternatively, the processing unit comprises a central processing unit (CPU).

[0203] The invention relates to a computer program product comprising the computer-readable medium containing instructions which, when executed by the processing circuit, cause the system S to implement the steps of the method according to the invention, i.e. to execute the functional building blocks of the system according to the invention.

[0204] The program product may include the computer-readable recording medium.

[0205] Alternatively, the program instructions are obtained from an external source and downloaded via a network. This is particularly the case for applications. In this case, the computer program product comprises a computer-readable data carrier on which the program instructions are stored or a data carrier signal on which the program instructions are encoded.

[0206] The form of the program instructions is, for example, a source code form, a computer-executable form, or any intermediate form between a source code and a computer-executable form, such as the form resulting from the conversion of the source code via an interpreter, an assembler, a compiler, a linker, or a locator. Alternatively, the program instructions are microcode, firmware instructions, state definition data, integrated circuit configuration data (e.g., VHDL), or object code. The program instructions are written in any combination of one or more programming languages, for example, an object-oriented programming language (C++, JAVA, Python), a procedural programming language (e.g., C language).

[0207] The COI, CO2 communication systems allow communication between the elements of the system and possibly between at least one element of the system and a device external to the system. The communication systems can establish a physical link between elements of the system and / or between an element of the system and a device external to the system and / or a remote communication link (wireless) between elements of the system and / or between an element of the system and a device external to the system.

[0208] The communication systems may comprise any hardware, firmware and / or software suitable for communicating information between elements of the device to which the communication system belongs, for example via a data bus, or to an element external to the device. In order to enable the communication of data between different devices to which the systems belong communication systems, these systems include firmware and / or software hardware allowing a wired or wireless communication link to be established between them, for example Wi-Fi, Bluetooth, cellular or Ethernet.

[0209] The user interface INT allows a user to enter data or commands so as to be able to interact with the programs according to the invention.

[0210] The user interface INT comprises, for example, an interface and output INTS and an input interface INTE.

[0211] The input interface includes, for example, a keyboard or a pointing interface, such as a mouse, a light pen, a touchpad, a remote control, a voice recognition device, a haptic device.

[0212] The output interface INTS is designed to restore information to a user, in a sensory or electrical manner, such as, for example, visually or audibly. The output interface comprises, for example, a display. The display step AFF; can then be a step of restoring information from data generated during the processing of block of order i by the output interface INTS, by a means other than a display.

[0213] The output interface INTS can be the input device INTE, for example, in the case of a touch tablet.

[0214] The invention also relates to a computer program product comprising instructions which cause the system according to the invention to execute the steps of the method according to the invention as well as to a computer-readable medium, on which the computer program is recorded. Special material realization

[0215] In a particular embodiment of the invention, the DA acquisition device comprises a housing containing and / or supporting the elements of the DA acquisition device shown in [Fig.6]. The DA acquisition device forms an object intended to be connected by wire to the probe S.

[0216] In the particular embodiment of [Fig.6], the processing system is a DT processing device, for example a microcomputer, intended to be connected in communication in a wired or wireless manner, for example via a Wifi network, to the DA acquisition device.

[0217] Alternatively, the DA acquisition device is integrated into the DT processing device.

[0218] In a particular embodiment, the processing device DT is a microcomputer, for example, a portable computer or one that can be transported by a human.

[0219] It is, for example, capable of being mounted on casters so that a human can move it easily.

[0220] Alternatively, the processing system comprises a first processing device comprising the second MDT memory and the processing unit. The processing system processing comprises an output device comprising the INT interface or the INTS output interface communicatively connected, for example wirelessly or wired, with the processing device, by the CO2 communication system. The output device is, for example, a telephone or a tablet. Alternatively, the processing unit UT is distributed between the first processing device and the output device so that the output device performs part of the block processing.

Claims

Claims

1. A method for acquiring and processing ultrasonic waves comprising the sequential acquisition of N elementary data blocks (B;) of order i, with i = 1 to N, and the sequential processing (T), implemented by computer, of the elementary data blocks (B;), the order i of each raw elementary data block (B;) being the acquisition order number of the data block (B;) among the N data blocks, the sequential acquisition (A) comprising, for each elementary data block, the acquisition (Ai) of the data block (B;) of order i comprising J implementations of a sub-block acquisition of data of order j (SBÿ), for j = 1 to J with J greater than 1, the sub-block acquisition comprising for each transmission / reception configuration (Ch) of a set of at least one transmission / reception configuration (Ch) defined by a transmission sub-aperture (SOo) and a reception sub-aperture (SOo') of an array (R) of transducers (TR), a set of at least one individual acquisition sequence (siijhk) comprising:; • Emission (Ehk) of an ultrasonic beam (Wk), by the emission sub-aperture (SOo), in an area of ​​interest of a patient, • Reception (Rhk), by the reception sub-aperture (SOo'), of echoes generated by the area of ​​interest under the effect of the ultrasonic beam, so as to generate electrical signals, • Preprocessing (PT^) including the digitization of signals from electrical signals in order to generate an elementary data set (RFhkji), the sequential processing (T) comprising, for at least one of the elementary data blocks (B;) of order i, a block processing (TB;) of order i, implemented by computer, comprising, for at least one data sub-block (SBÿ) of order j, an elementary processing (TBÿ) comprising the combination (COMB) of data of the data sub-block (SBÿ) of order j so as to generate an elementary image (IEÿ), the block processing (TB;) of order i being implemented during the acquisition (Ai+k0) of order i+kO with kO being an integer greater than 0, i+kO being less than or equal to N.

2. Method according to the preceding claim, in which the treatment of block (TB;) of order i is implemented during the acquisition (Ai+i) of the data block (Bi+i) of order i+1.

3. Method according to any one of the preceding claims, wherein the block processing (TB;) of order i is implemented only during the acquisition (Ai+k0) of the data block (Bi+k0) of order i+kO.

4. Method according to any one of the preceding claims, comprising, during the acquisition (Ai+k0) of the data block of order i+kO, the provision to a user, via a user interface (INT), of information from data generated during the processing of block (TB;) of order i.

5. Method according to any one of the preceding claims, in which the elementary processing (TB;j) comprises the improvement (AM) of signals coming from contrast agents (MB) on the elementary image (IEÿ) compared to other signals so as to obtain an improved elementary image (IAy).

6. Method according to any one of the preceding claims, in which the elementary processing (TBy) comprises the detection of signals originating from contrast agents on the elementary image or on an image originating from the elementary image (IEy) so as to obtain a set of positions of contrast agents (PSym).

7. Method according to any one of the preceding claims, in which the block processing (TB;) of order i comprises the tracking (SU) of contrast agents on several elementary images or images originating from elementary images.

8. Method according to any one of the preceding claims, in which the block processing (TB;) of order i comprises elementary processings (TBy) implemented for respective sub-blocks of data, in parallel.

9. Method according to any one of the preceding claims, in which the individual acquisition sequence (siijhk) comprises the storage of the set of elementary data in a first memory (MT), the method comprising, the transfer of the block of elementary data of order i to a second memory (MDT), implemented, at least in part, prior to the block processing (TB;).

10. Method according to the preceding claim, in which the first memory (MT) and the second memory (MDT) are random access memories, the block of elementary data being transmitted from the first memory (MT) to the second memory (MDT) without passing through another memory.

11. System for acquiring and processing ultrasonic waves configured to implement the method according to any one of the preceding claims, the acquisition and processing system comprising: • An acquisition system (SA) comprising the network (R) of transducers (TR) and configured to implement the acquisition step (A), • A processing system (DT) configured to implement the sequential processing step (T).

12. System according to claim 11 configured to implement the method according to any one of claims 9 to 10, wherein the acquisition system (SA) comprises the first memory (MT) and the processing system (DT) is intended to be connected in communication with the acquisition system (SA), the processing system (SA) comprising the second memory (MDT).

13. A computer program product comprising instructions which cause the system according to claim 11 to execute the steps of the method according to claim 1.

14. A computer-readable medium on which the computer program according to claim 13 is recorded.

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