A method for morphological processing of microwave radar images in the medical field, using different hypotheses about the medium through which microwave signals pass.

Abstract

The present invention relates to a method for processing medical images of a region of a patient's body, in particular human tissue of the breast, by means of a medical imaging device (1), the medical imaging device (1) comprising a microwave probe array comprising K>1 probes spaced apart from one another, the array comprising P>1 different configurations defining transmitting and receiving probes for one or more positions around the region, the transmitting probes configured to transmit microwave signals to illuminate the region of the body and the receiving probes configured to receive the microwave signals after scattering and reflection in the region, the probes may be configured to transmit and receive simultaneously in a complementary manner.

Description

Technical Field

[0001] The present invention relates to the field of medical image processing using electromagnetic waves in the microwave frequency band, and more specifically, to medical image processing for the analysis of human tissues or organs that transmit electromagnetic waves. Further, the present invention is particularly applicable to breast image processing and the detection of breast pathologies.

Background Art

[0002] Microwave image processing technology enables the image processing of human organs that transmit electromagnetic waves and is a promising technology in the fields of breast image processing and the detection of pathologies such as breast cancer.

[0003] Microwave image processing uses a radiation probe configured to irradiate all or part of an organ that will be imaged by electromagnetic waves. The radiation wave passes through the area to be imaged and is received by a receiving probe. The probes can be configured to radiate and receive simultaneously in a complementary manner. The received wave passes through the area to be imaged, which will be imaged by passing through reflections at obstacles encountered at the positions of the dielectric contrast (e.g., cancer lesions located in healthy tissue). All of the transmission coefficients measured between the radiation probe and the receiving probe in this way form a multistatic acquisition. These multistatic acquisitions serve as inputs to a radar image processing module and further enable the obtaining of 2D or 3D radar images of an organ or part of an organ.

[0004] In order to obtain an image that best represents the area to be imaged, it is necessary to know in advance the dielectric medium along the different paths through which the electromagnetic wave travels between the radiation probe, each point of the area to be considered that will be imaged, and the receiving probe.

[0005] However, this prior knowledge of the dielectric properties of the organ to be imaged is difficult to obtain, and assumptions have to be made about the medium being traversed, which results in an image that can be of low quality.

Summary of the Invention

[0006] This invention makes it possible to improve the quality of radar images for the analysis of human tissues or organs. In particular, this invention makes it possible to detect in radar images one or more regions of interest corresponding to physical objects that may constitute a lesion. [Means for solving the problem]

[0007] To achieve this objective, the present invention proposes a method for processing medical images of a region of a patient's body, particularly of human tissue of the breast, using a medical image processing apparatus according to a first aspect, the medical image processing apparatus comprising an array of probes that emit / receive microwave electromagnetic waves, including K>1 probes spaced apart from each other, the array comprising different configurations of P>1 that define emitting and receiving probes for one or more positions around the region, the emitting probes being configured to emit microwave signals to illuminate the region of the body, the receiving probes being configured to receive microwave signals after diffusion and reflection to the region, the probes may be configured to emit and receive simultaneously in a complementary manner, the method being carried out in a processing unit of the medical image processing apparatus as follows: - Step 1: Obtain the signal generated by the antenna array with a P>1 configuration; Includes, The method applies to each configuration as follows: -

[0008]

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[0009] The present invention is advantageously complemented by the following features, which may be employed individually or in any possible technical combination thereof: - Morphological processing essentially involves determining the solidity of one or more pixel regions in an image, and a region of interest is identified when the relevant solidity is greater than a threshold. - At least N=2 sets, preferably at least N=3 sets (1≦i≦N), of Ai>1 values ​​for the characteristic parameter (pcfib) of the medium the signal crosses are considered. - The sets overlap entirely or partially in terms of the range of variation and / or the values. - The assessment of persistence essentially involves determining the proportion of regions of interest present in morphological images, where regions of interest are validated for proportions greater than a threshold. - The array of probes includes K > 1 probes arranged around the area to be imaged, the array being movable in a vertical position around the area to be imaged, each configuration being an angular sector of probes each composed of M > 1 probes (M < K), each configuration being angularly offset from another configuration by at least one probe; for each sector, each of the probes is alternately in a radiating state so as to generate a signal acquired for the configuration, and a basic radar image is determined for each angular sector for each set of values of characteristic parameters.

[0010] According to a second aspect, the present invention proposes a computer program product including program code instructions for executing the steps of the method according to the first aspect of the present invention when the method according to the first aspect of the present invention is executed by at least one processor.

[0011] According to a third aspect, the present invention proposes a medical image processing apparatus including a processing unit configured to implement the method according to the first aspect of the present invention.

[0012] The combination of some configurations and the use of some characteristic values of the medium to be traversed, by way of assumption, make it possible to manage the non-uniformity of the dielectric properties of the area to be imaged that is not previously known.

[0013] Furthermore, the persistence of the region of interest morphologically identified for at least B > 1 sets (B / N ≤ 1) among the N sets means the verification of the region of interest, i.e., a strong probability pair against an artifact corresponding to a physical object / lesion present in the imaged area.

[0014] In a complementary manner, the criterion of solidity used is a shape descriptor that enables advantageous morphological identification of the region of interest.

Brief Description of the Drawings

[0015] Other features, objects, and advantages of the present invention will become apparent from the following description, which is given purely by way of example and is not limiting, and should be read in conjunction with the accompanying drawings.

[0016] In all the figures, like elements have the same reference numerals. [Figure 1] FIG. 1 is a schematic diagram illustrating a microwave medical imaging system according to an embodiment of the present invention. [Figure 2] FIG. 2 is a diagram illustrating steps of a method for performing morphological processing of a microwave radar image according to the present invention. [Figure 3] FIG. 3 is a diagram illustrating a microwave radar image obtained during the method according to the present invention. [Figure 4] FIGS. 4a, 4b, 4c, 4d, 4e are diagrams illustrating morphological images of a patient's breast obtained by a method for performing morphological processing of a microwave radar image according to the present invention. [Figure 5] FIGS. 5a, 5b, 5c, 5d are diagrams illustrating morphological images of a patient's breast obtained by a method for performing morphological processing of a microwave radar image according to the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] FIG. 1 illustrates a microwave medical imaging apparatus 1 including an examination table 11 on which a patient 12 lies. In particular, the patient 12 lies prone. The examination table 11 preferably includes a circular opening 13 that allows the patient's breast 14 to be immersed in a tank 15 filled with a biocompatible transition liquid, and the dielectric properties of the biocompatible transition liquid are optimized to improve the transmission of electromagnetic waves into the breast.

[0018] An array 16 of microwave-range electromagnetic radiation / receiving probes 161 (hereinafter given by dashes) is arranged around the tank 15, enabling the medium to be observed to be irradiated and the reflected signals to be imaged to be received. The probes 161 are advantageously distributed uniformly around the tank, preferably in a ring-like arrangement surrounding the tank, as illustrated in Figure 1. Advantageously, the probes are configured to radiate signals in the 0.5–6 GHz frequency band.

[0019] More generally, image processing systems operate in a multistatic manner, enabling the illumination of the medium to be imaged by using several probes in a radiating state and several probes in a receiving state, and by various configurations around the medium to be imaged. The probes can be configured to radiate and receive simultaneously in a complementary manner.

[0020] In each multistatic acquisition, all or part of the medium to be imaged is continuously illuminated by a pre-selected probe operating in the emitting state. The number of emitting probes in the array is selected according to the area of ​​the breast to be imaged. For each emitting probe, a signal is received by a pre-selected probe operating in the receiving state. The number of receiving probes in the array is selected according to the area of ​​the breast to be imaged. Each multistatic acquisition is then considered to correspond to the emission / reception of a series of signals by the probes in the determined configuration.

[0021] Therefore, configuration means defining a set of radiating probes and a set of receiving probes that enable multistatic acquisition of all or part of the breast, and these probes are positioned in a specific manner in the space surrounding the breast.

[0022] To switch from one configuration to another and to control various multistatic acquisitions, the system includes a unit 17 for controlling an array of probes connected to a monitoring and processing unit 18 (e.g., a processor and / or computer). Such a monitoring and processing unit 18 is configured to control the array, perform acquisitions, ensure storage of acquired data, perform radar image processing operations, and further implement the morphological image processing methods described below. A storage unit 19 enables the storage of all acquired multistatic data and a certain number of data that can be used in the image processing steps or generated by image processing. Furthermore, a display unit 20 enables the display and visualization of the obtained images. The monitoring and processing unit 18, the storage unit 19, and the display unit 20 can be directly integrated into the image processing apparatus or can be physically moved. Image processing operations can be performed retrospectively (offline).

[0023] To understand this, several consecutive configurations of radiation and receiving probes are defined for imaging the entire breast. These configurations of radiation and receiving probes are selected to cover various regions of the breast to be imaged, ultimately encompassing the entire breast to be imaged.

[0024] For each configuration, multistatic acquisition of the transmission coefficient between the radiating probe and the receiving probe makes it possible to obtain the basic radar image after radar image processing.

[0025] All of the obtained basic images enable the reconstruction of 2D or 3D radar images of the imaged region, in this case the breast. For radar processing of multistatic emitted / received signals that enables the reconstruction of 2D or 3D radar images, see, for example, the following literature: - AJ Devaney, Time reversal imaging of obscured targets from multistatic data, IEEE Trans. Antennas Propag. (2005). doi:10.1109 / TAP.2005.846723; - Marengo, EA; Gruber, FK; Simonetti, F. Time-reversal MUSIC imaging of extended targets. IEEE Trans. Image Process. 2007, 16, 1967-1984. doi:10.1109 / TIP.2007.899193; - Hossain, MD; Mohan, AS Cancer Detection in Highly Dense Breasts Using Coherently Focused Time-Reversal Microwave Imaging. IEEE Trans. Comput. Imaging 2017, 3, 928-939. doi:10.1109 / TCI.2017.2737947; - A. Fasoula, BM Moloney, L. Duchesne, JDG Cano, BL Oliveira, J. Bernard, MJ Kerin, Super-resolution radar imaging for breast cancer detection with microwaves: the integrated information selection criteria, in: 41st Annu. Int. Conf. IEEE Eng. Med. Biol. Soc., 2019 It is possible to refer to this.

[0026] The obtained 2D or 3D radar images are advantageously used as part of the processing methods described below.

[0027] As mentioned in the introduction, determining each basic radar image theoretically requires prior knowledge of the dielectric medium of the breast along the path extending between each radiating probe and each receiving probe (i.e., the medium being traversed). However, this is difficult to obtain.

[0028] As described, the present invention uses a pcfib parameter, in terms of dielectric constant, that corresponds to an assumption regarding the average composition of the medium through which electromagnetic waves traverse the breast (or, more generally, the region being imaged). This pcfib parameter corresponds to the ratio of the mixture of fibrous tissue and adipose tissue in the breast. For example, pcfib = 30% corresponds to a medium having 30% fibrous tissue and 70% adipose tissue. The dielectric properties of the breast tissue are then defined as a weighted average (weighted by pcfib) of the dielectric properties of the fibrous tissue and adipose tissue. For examples of dielectric constant values ​​for fibrous tissue and adipose tissue in the breast, see, for example, the following literature: - T. Sugitani, SI Kubota, SI Kuroki, K. Sogo, K. Arihiro, M. Okada, T. Kadoya, M. Hide, M. Oda, T. Kikkawa, Complex permittivities of breast tumor tissues obtained from cancer surgeries, Appl. Phys. Lett. (2014). doi:10.1063 / 1.4885087; - M. Lazebnik, L. McCartney, D. Popovic, CB Watkins, MJ Lindstrom, J. Harter, S. Sewall, A. Magliocco, JH Booske, M. Okoniewski, SC Hagness, A large-scale study of the ultrawideband microwave dielectric properties of normal breast tissue obtained from reduction surgeries, Phys. Med. Biol. (2007). doi:10.1088 / 0031-9155 / 52 / 10 / 001 It is possible to refer to this.

[0029] A method for morphological processing of microwave radar images is described below in relation to Figure 2.

[0030] Firstly, one or more P>1 configuration probe arrays (step E0) are defined to encompass the entire breast to be imaged and to allow for the subsequent reconstruction of a 3D radar image of the breast.

[0031] Next, for each configuration, a multistatic acquisition of the transmission coefficient measured between the radiating probe and the receiving probe is performed (step E1). Then, there are multiple multistatic acquisitions (multistatic acquisitions for P>1).

[0032] Next, the signals acquired for each configuration are processed to obtain a basic microwave radar image for each configuration (Step E2).

[0033] In particular, to process these signals, the Ai values ​​(values ​​of Ai > 1, 1 ≤ i ≤ N) of several sets (N > 1 sets) of pcfib parameters are considered. Then, for each configuration, the pcfib parameters are...

[0034]

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[0035]

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[0036] Conveniently, the sets of values ​​for the PCFIB parameters overlap entirely or partially in terms of variability and / or value.

[0037] For example, it is possible to have one set containing values ​​of 10% and 20%, and another set containing values ​​of 5%, 15%, and 25%. In this example, there is one set where the values ​​vary between 10% and 20%, and another set where the values ​​vary between 5% and 25%. Thus, these two sets share a common range of variation from 10% to 20%.

[0038] In another example, it is possible to have one set containing the values ​​10% and 20%, and another set containing the values ​​20%, 25%, and 30%. In this example, the sets have one value in common: 20%.

[0039] In yet another example, it is possible to have one set containing values ​​of 10%, 20%, and 25%, and another set containing values ​​of 5%, 10%, and 30%. In this example, these two sets have a common range of variation from 10% to 25%, and one common value of 10%.

[0040] At least two sets of pcfib parameter values ​​are considered, one of which may have a wider range of variation for the pcfib parameter values ​​than the other set. Here, the terms wider and narrower are relative terms understood by comparing the ranges of variation. The idea here is that there is overlap between the sets of values.

[0041] The selection of the range of variation for the pcfib parameters for various sets is made in relation to existing variability in breast composition and density.

[0042] Advantageously, a wide range of variation leads to images containing a more complete representation of the region of interest, while a narrow range of variation potentially leads to a partial representation of detectable lesions.

[0043] For example, in relation to breast image processing, we can choose N=5 sets of variations: - Three sets with a narrow range of variation: - Between 10% and 20%, the pcfib parameter can take values ​​within this range, for example: 10%, 15%, 20%. - Between 30% and 40%, the pcfib parameter can take values ​​within this range, for example: 30%, 35%, 40%. - Between 50% and 60%, the pcfib parameter can take values ​​within this range, for example: 50%, 55%, 60%. - Two sets with a wide range of variation: - Between 20% and 50%, the pcfib parameter can take values ​​within this range, for example: 20%, 25%, 30%, 35%, 40%, 45%, 50%. - Between 10% and 60%, the pcfib parameter can take values ​​within this range, for example: 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%.

[0044] For each configuration, a basic microwave radar image is selected for each set (step E3), corresponding to one of the set's parameter values ​​(pcfib); thus, one basic image is selected for each configuration, per set. Such selected images may have regions of interest corresponding to potentially pathological physical objects. In the previous example, there are five basic images per configuration (one basic image per set), which will be used for reconstruction.

[0045] Such choices are particularly relevant to the following literature: - S. Pertuz, D. Puig, MA Garcia, Analysis of focus measure operators for shape-from-focus, Pattern Recognit. (2013). Doi :10.1016 / j.patcog.2012.11.011 - O'loughlin, D.; Krewer, F.; Glavin, M.; Jones, E.; O'halloran, M. Focal quality metrics for the objective evaluation of confocal microwave images. Int. J. Microw. Wirel. Technol. 2017, 9, 1365-1372. Doi :10.1017 / S1759078717000642 The essential point is to use at least one of the image focusing criteria (image focusing metrics) described therein (a combination of several criteria can be used).

[0046] Each selected image may have one or more regions of interest, and these selections are made according to at least one image focusing criterion. In practice, selection is made by one or more focusing criteria. For example, for a chosen criterion, this includes, for example, selecting the image that gives the minimum metric value from all others for that criterion.

[0047] Note that the selection of base images for the same given set, when moving from one configuration to another, can be done using different values ​​for the pcfib parameters belonging to that set.

[0048] From the base images obtained for various configurations, a 2D or 3D radar image of the region to be imaged is reconstructed for each set (step E4). Thus, there is one reconstructed radar image for each set of pcfib values.

[0049] In each microwave radar image of the imaged region thus reconstructed, morphological processing is applied to detect regions of interest if they exist (step E5). The resulting image is called a microwave morphological image, which has zero or one or more identified regions of interest. Such morphological processing is essential in that it identifies the objects of interest in the image, particularly by using thresholding methods, and preserves the objects of interest as regions of interest, corresponding to a set of morphological features, in particular, the volume size of the objects of interest, the level of solidity of the objects of interest, the internal intensity level of the objects of interest, the contrast level between the internal intensity of the objects of interest and the internal intensity of other potentially identified objects of interest in the same image, etc. At this stage, there are several morphological images of breasts, each morphological image obtained for each set of pcfib values; each morphological image has zero or one or more identified regions of interest.

[0050] Preferably, morphological processing is based on a solidity criterion. Solidity is calculated as the ratio between the volume of the object and the volume of the convex hull of the object. In general, the greater the solidity of the region of interest, the more "filled" (a region of interest without holes) the region of interest will have a clearer, more convex contour, and therefore the significantly higher the probability that it must correspond to a mass. In the case of breast imaging processing, this solidity criterion may be intended to support the differentiation between breast masses and local asymmetry ("islands" of normal breast tissue without a clear convex outer border). This concept of a clear, convex contour in a solid breast mass is illustrated, for example, in the following literature: - TF de Brito Silva, AC de Paiva, AC Silva, G. Braz Junior, JDS de Almeida, Classification of breast masses in mammograms using geometric and topological feature maps and shape distribution, Res. Biomed. Eng. (2020). doi:10.1007 / s42600-020-00063-x - N. Safdarian, M. Hedyezadeh, Detection and Classification of Breast Cancer in Mammography Images Using Pattern Recognition Methods, Multidiscip. Cancer Investig. (2019). doi:10.30699 / acadpub.mci.3.4.13 It is explained in [the document].

[0051] In practice, the solidity of the region of interest must exceed a given level so that this region of interest can be identified in a given set of morphological images.

[0052] Next, the persistence of each previously identified region of interest is evaluated across various morphological images. The objective is to morphologically verify the persistence of regions of interest for several assumptions across the medium through which electromagnetic waves traverse (Step E6). Evaluating persistence means that the region of interest exists in 3D within the same region across several morphological images. Here, we evaluate whether the regions of interest identified by morphological processing exist in the same region across several images. Such evaluation is essential, in particular, to correlate the detected regions of interest together using criteria such as spatial clustering.

[0053] Therefore, persistence allows for morphological verification of the region of interest, that is, it allows for verification of their association with physical objects if the region of interest exists in proportion to the number of determined morphological images.

[0054] As shown, advantageously, at least two sets of PCFIB values, preferably at least three sets of PCFIB values, are considered. This is important for performing the persistence assessment step. In practice, a region of interest will be considered valid if it persists across several morphological images. In the case of two sets, the region of interest must be present in both images for it to be valid. In the case of three sets, the region of interest must be present in two of the three images or three of the three images for it to be valid.

[0055] Generally speaking, a region of interest is considered persistent if it exists in a proportion of morphological images that must be determined according to the type of region being sought.

[0056] Thus, these areas of interest validated by persistence are more likely to correspond to genuine lesions or tumors rather than artifacts. This persistence can be correlated with confidence in the detection level.

[0057] In a complementary fashion, the image processing system is contemplated to include a horizontal circular array of K>1 measurement probes arranged around a cylinder made of a dielectric material. The circular array may move along a vertical axis. The organ (breast) under inspection is placed inside the cylinder and is thus surrounded by this array. The dielectric transition medium contained within the cylinder in which the breast is placed enables optimizing the transmission of electromagnetic waves radiated by the probes inside the breast. The vertical position of the array is predefined and there is a fixed or variable distance interval between each position, covering the vertical extent of the breast.

[0058] For each of the vertical positions of the probe array, a multistatic measurement is performed.

[0059] As an example of the implementation of the acquisition step, L>1 angular sectors each composed of an array of M>1 probes (M<K) are considered. For example, an L = 18 angular sector of M = 6 probes, in which case each sector is angularly offset relative to each other by R = 1 probe along the periphery of an array of K = 18 probes.

[0060] For each of the angular sectors of M = 6 probes, each of the probes is alternately in a radiating state, and for each radiating probe, the other probes of the angular sector continuously receive signals corresponding to echoes, particularly from obstacles encountered in the breast. All the transmission coefficients measured between the radiating and receiving probes of the considered angular sectors form a multistatic acquisition. This multistatic acquisition is repeated for a set of L = 18 angular sectors of M = 6 probes. Next, the vertical array is moved at an interval along the vertical axis and the multistatic measurement is repeated for different angular sectors.

[0061] Next, the array configuration corresponds to angular sectors at a given vertical position. Acquisition for each angular sector allows for traversing the circumference of the breast by making several assumptions about the pcfib value in each angular sector at each vertical position. This allows for optimal consideration of the variable heterogeneous structure of the breast with respect to dielectric properties that may change according to different observation positions, and for revealing the angular response of non-uniform breast lesions.

[0062] Thus, by combining different assumptions about the pcfib parameters, sectorization of the region to be imaged is utilized to improve the detection of regions of interest.

[0063] Types of images obtained by the present invention Figure 3 illustrates a reconstructed microwave radar image for a set of PCFIB values, such as 10% ≤ PCFIB ≤ 60%. This radar image represents the coronal plane of the breast. In this radar image, several pixel regions are visible in terms of intensity.

[0064] The purpose of morphological processing is to process this type of radar image to identify regions of interest that may correspond to areas of suspicion.

[0065] Figures 4a, 4b, 4c, 4d, and 4e illustrate several morphological images of a patient's breast obtained after morphological processing of reconstructed microwave radar images for five sets of PCFIB parameter values. These morphological images are represented in the coronal plane of the breast. In this example, the morphological images are based on the following five sets of PCFIB parameter values: - Figure 4a: 10% ≤ pcfib ≤ 60% - Figure 4b: 20% ≤ pcfib ≤ 50% - Figure 4c: 10% ≤ pcfib ≤ 20% - Figure 4d: 30% ≤ pcfib ≤ 40% - Figure 4e: 50% ≤ pcfib ≤ 60% It supports this.

[0066] In light of the radar image in Figure 3, morphological processing allows for the identification of only one region of interest. This region of interest persists across five morphological images and is therefore valid.

[0067] In each morphological image, it was observed that the identified region of interest had a different contour, confirming that the microwave radar characteristics of the detected object vary depending on the set of PCFIB values ​​considered.

[0068] Figures 5a, 5b, 5c, and 5d illustrate morphological images of another patient's breast obtained after morphological processing of reconstructed microwave radar images for five sets of pcfib parameter values. These five sets of values ​​are the same as those considered in the previous figure (previous patient). In this example, the morphological processing allowed for the identification of a single region of interest that persists across four of the five morphological images. Thus, this region of interest is valid. A fifth morphological image corresponding to the set of values ​​10% ≤ pcfib ≤ 20% is not shown because no persistent region of interest is identified there. Unlike the previous example, the identified region of interest has a group shape, which remains the same and is the only relevant object following the previously applied processing behavior. This illustrates that the microwave radar properties of the detected object vary considerably depending on the set of pcfib values ​​considered. The region of interest corresponds to a lesion with a distributed, highly heterogeneous shape and highly heterogeneous texture.

Claims

1. A method for processing a medical image of a region of a patient's body, particularly of human tissue of the breast, using a medical image processing device, wherein the medical image processing device includes an array of probes that emit / receive microwave electromagnetic waves, including K>1 probes spaced apart from each other, the array includes different configurations P>1 that define emitting and receiving probes for one or more locations around the region, the emitting probes are configured to emit microwave signals to illuminate the region of the body, the receiving probes are configured to receive microwave signals after diffusion and reflection to the region, the probes can be configured to emit and receive simultaneously in a complementary manner, the method being carried out in the processing unit of the medical image processing device as follows: - Step of acquiring the microwave signal generated by an antenna array with a P>1 configuration. Includes, The method applies to each configuration, － [Math 1] A step of processing the microwave signal obtained for N>1 sets (1≦i≦N) of Ai>1 values ​​of parameter (pcfib) features of the human tissue that the microwave signal crosses, in order to obtain a basic microwave radar image of the human tissue, - A step of selecting a basic microwave radar image in each of N sets according to at least one image focusing criterion, wherein each selected basic image corresponds to one of the parameter (pcfib) values ​​of the N sets, and one basic image is selected for each set for one configuration. Includes, This method applies to each set, - Reconstructing each of the aforementioned configurations of radar images of a region of the patient's body such that one 3D radar image is reconstructed for each set from the selected basic radar images, - If there are one or more regions of interest that may constitute a lesion, the step of performing morphological processing on each reconstructed radar image to obtain a morphological image in which the one or more regions of interest are identified. - A step to evaluate the persistence of each region of interest in different morphological images obtained in order to perform morphological verification of the region of interest. Methods that include...

2. The method according to claim 1, wherein the morphological processing is essentially about determining the solidity of one or more pixel regions of the image, and a region of interest is identified when the relevant solidity is greater than a threshold.

3. The method according to claim 1, wherein at least N=2 sets (1≦i≦N) of Ai > 1 values ​​of the characteristic parameter (pcfib) of the medium through which the microwave signal passes are taken into consideration.

4. The method according to claim 3, wherein the set of values ​​for the characteristic parameters overlaps in whole or in part in terms of range of variation and / or value.

5. The method according to claim 1, wherein the evaluation of persistence is essentially about determining the proportion of the region of interest present on the morphological image, and the region of interest is validated for proportions greater than a threshold.

6. The method according to claim 5, wherein the array of probes includes K>1 probes positioned around a region to be imaged, the array is movable in a vertical position around the region to be imaged, each configuration is an angular sector of probes, each consisting of M>1 probes (M<K), each configuration is angularly offset by at least one probe relative to another configuration, and for each angular sector, each of the probes is alternately radiating to generate a microwave signal to be acquired relative to the configuration, and a basic radar image is determined for each angular sector for each set of feature parameter values ​​(pcfib).

7. A computer program comprising program code instructions for performing the steps of the method described in claim 1 when the method is performed by at least one processor.

8. A medical image processing apparatus comprising a processing unit configured to carry out the method described in claim 1.