Control device for magnetic resonance imaging system, imaging assembly and associated process

Abstract

A control device (3) for a magnetic resonance imaging system (1) for generating a diffusion image of an animal body (6) is proposed. Figure for the abstract: Fig 1

Description

Title of the invention: Control device for magnetic resonance imaging system, imaging assembly and associated method

[0001] The present invention relates to the field of magnetic resonance imaging (MRI) systems, and relates more particularly to a control device for a magnetic resonance imaging system for generating a diffusion image of an animal's body, a magnetic resonance imaging assembly comprising a magnetic resonance imaging system and such a device, and a magnetic resonance imaging method for generating a diffusion image of an animal's body.

[0002] Generally in human medicine, whole-body MRI imaging is performed to represent the human body.

[0003] Whole-body MRI imaging corresponds to the acquisition of high-resolution images on limited segments of the body, which are then fused to reconstruct the body.

[0004] Whole-body MRI imaging combines anatomical sequences and diffusion imaging sequences.

[0005] Diffusion-weighted imaging sequences allow the detection of lesions, for example metastatic or lymph node lesions, thanks to the high contrast between the lesions and their surroundings, and add a metabolic dimension to the imaging examination. They assess the diffusion properties of water molecules and reflect cellular richness and the integrity of cell membranes over time.

[0006] Anatomical sequences make it possible to localize lesions and to recognize the few false positive observations of diffusion imaging constructed from diffusion sequences.

[0007] In human medicine, the fields of view commonly used are between 48 and 50 cm with a relatively low spatial resolution.

[0008] The implementation of whole-body MRI imaging in veterinary medicine, for example to reconstruct the body of a dog or cat from the parameters of an MRI scan performed on a human body, presents insufficient spatial resolution to represent relevant information, including lesions.

[0009] Reducing the field of view and increasing spatial resolution when examining an animal's body results in increased noise and loss of the signal representing the diffusion of water molecules in the animal's body, so that the image obtained is of poor quality for making a diagnosis

[0010] In view of the foregoing, the invention aims to overcome all or part of the aforementioned drawbacks in order to perform whole-body MRI imaging of an animal that can be used to obtain a relevant representation of the lesions.

[0011] The invention relates to a magnetic resonance imaging method for generating a diffusion image of an animal body comprising:

[0012] - a first stage of diffusion sequences in strict transverse acquisition with respiratory compensation of a first field of view, the size of the first field of view extending between 30 and 48 cm so that the animal's body is entirely included within the first field of view, the first stage of diffusion sequences comprising:

[0013] o a first set of tracking sequences comprising the acquisition of a first group of slices of the animal contained in the first field of view along a transverse direction of the animal, the first group of data slices comprising slices of thickness between 2 and 6 mm,

[0014] or a second set of diffusion sequences in planar echo imaging comprising, for each slice of the first set of slices, an emission of a plurality of excitation pulses separated from each other by a first repetition duration greater than 4500 ms and less than 10000 ms,

[0015] o each first excitation pulse comprising:

[0016] - the emission of a first electromagnetic wave of radio frequency to put in phase the spins of the hydrogen protons contained in said cup,

[0017] - after an echo duration divided by two following the emission of the first radio frequency electromagnetic wave, the emission of a second radio frequency electromagnetic wave to compensate for the phase shift due to inhomogeneities in said section and simultaneously with the emission of the second radio frequency electromagnetic wave, the emission of a first set of gradients comprising the emission of a first gradient in the sagittal plane of the animal, a second gradient in the dorsal plane of the animal, and a third gradient in the transverse plane of the animal, the amplitude of the first, second and third gradients being identical and equal to a first gradient value allowing a diffusion of hydrogen atoms between 600 s / mm2 and 2000 s / mm2, preferably equal to 800 s / mm2 of the hydrogen atoms included in the first field of view, and

[0018] - after an echo duration beginning after the emission of the first wave radio frequency electromagnetics, the collection of a first resulting signal, the first signal being representative of the magnetic field generated by each hydrogen atom in said section along the sagittal, dorsal and transverse planes of the animal, said hydrogen atom being excited by radio electromagnetic waves frequencies and the first set of gradients, with the echo duration being between 45 ms and 100 ms,

[0019] or a reconstruction of a first set of three diffusion images for each slice of the first set of slices from the first signal resulting from said slice, and

[0020] o a fusion of the diffusion images of the first set of sections to obtain a first diffusion image of the animal's body.

[0021] The spatial resolution of the diffusion image of the animal's body is improved compared to known prior art veterinary MRI imaging in which the fields of view are reduced and the spatial resolution is increased when examining the body of an animal.

[0022] The diffusion sequence plateau acquired in strict transverse acquisition makes it possible to reduce eddy currents, reduce Nyquist artifacts and simplify registration.

[0023] Respiratory compensation helps to limit as much as possible the artifacts related to the movements of the animal's respiration.

[0024] The emission of a plurality of first excitation pulses having the first gradient value between 600 s / mm2 and 2000 s / mm2, preferably equal to 800 s / mm2 by the transmission and reception means makes it possible to increase the signal-to-noise ratio of the first signal resulting from each cut.

[0025] Preferably, the first stage of diffusion sequences further includes the detection of an expiratory plateau of the animal to determine the duration of the expiratory plateau and the respiratory rate, the first repetition duration being chosen so that the second set of diffusion sequences is included in the duration of the expiratory plateau.

[0026] Advantageously, the determination of the expiratory plateau duration and respiratory rate includes:

[0027] or an identification of the sections of the first set of sections comprising at least partially the liver and lungs of the animal, and

[0028] o an observation of the displacement of the liver and lungs from the identified sections of the first set of sections,

[0029] the expiratory plateau duration and respiratory rate being determined from the relative displacement of the liver with respect to the lungs.

[0030] Preferably, the second set of diffusion sequences further comprises the emission of a control excitation sequence simultaneously with each emission of a first excitation pulse, each control excitation sequence comprising:

[0031] - simultaneously with the emission of the second electromagnetic radio wave frequency, the emission of a second set of control gradients comprising the emission of a first control gradient in the sagittal plane of the animal, a second control gradient in the dorsal plane of the animal, and a third control gradient in the transverse plane of the animal, the amplitude of the first, second, and third control gradients being identical and equal to a second gradient value allowing a diffusion between 0 s / mm2 and 50 s / mm2, preferably equal to 50 s / mm2 of the hydrogen atoms included in the first field of view, and

[0032] - after the echo duration beginning after the emission of the first wave radio frequency electromagnetic, the collection of a first control signal, the first control signal being representative of the magnetic field generated by each hydrogen atom in said section along the sagittal, dorsal and transverse planes of the animal, said hydrogen atom being excited by radio frequency electromagnetic waves and the first set of gradients and the second set of control gradients,

[0033] the method further comprising:

[0034] or a reconstruction of a control set of three broadcast control images for each cut of the first set of cuts from the first control signal resulting from said cut,

[0035] o a fusion of the diffusion control images of the first set of sections to obtain a first diffusion control image of the animal's body, and

[0036] o the determination of a control map from the first diffusion image of the animal's body and the first diffusion control image of the animal's body.

[0037] Preferably, if the size of the animal is greater than 48 cm such that the animal's body is not entirely included in the first field of view, the method comprises the first stage of diffusion sequences and furthermore at least a second stage of diffusion sequences in strict transverse acquisition of a second field of view, the size of the second field of view extending between 30 and 48 cm and partially overlapping the first field of view, the first field of view covering a first area of ​​the animal delimited between the thorax and the abdomen of the animal to cover the pulmonary and abdominal areas of the animal, the second field of view covering a second area of ​​the animal delimited between the head and the shoulders of the animal or between the abdomen and the lower limbs of the animal such that the sum of the sizes of the fields of view of the stages of diffusion sequence is greater than or equal to the size of the animal,the second tier of broadcast sequences comprising: ,

[0038] or a third set of tracking sequences comprising the acquisition of a second group of data slices of the animal contained within the field of view of the second level of diffusion sequences along a transverse direction of the animal, the second group of data slices comprising slices of equal thickness to the thickness of the slices of the first group of data slices,

[0039] or a fourth set of diffusion sequences in planar echo imaging comprising, for each slice of the second set of slices, the emission of a plurality of second excitation pulses separated from each other by a second repetition duration greater than 4500 ms and less than 10000 ms,

[0040] o each second excitation pulse comprising:

[0041] - the emission of the first radio frequency electromagnetic wave for to phase the spins of the hydrogen protons contained in said section of the second set of sections,

[0042] - after the echo duration divided by two following the emission of the first radio frequency electromagnetic wave, the emission of the second radio frequency electromagnetic wave and simultaneously with the emission of the second radio frequency electromagnetic wave, the emission of the first set of gradients, and

[0043] - after the echo duration beginning after the emission of the first wave radio frequency electromagnetic, the collection of a second resulting signal, the second signal being representative of the magnetic field generated by each hydrogen atom in said section along the sagittal, dorsal and transverse planes of the animal, said hydrogen atom being excited by radio frequency electromagnetic waves and the first set of gradients,

[0044] or a reconstruction of a second set of three broadcast images for each cut of the second set of cuts from the second signal resulting from said cut, and

[0045] or a fusion of the images of the second set of sections of the second set of sections to obtain a second diffusion image of the animal's body.

[0046] Advantageously, the fourth set of diffusion sequences further comprises the emission of a control excitation sequence simultaneously with each emission of a second excitation pulse, each control excitation sequence comprising:

[0047] - simultaneously with the emission of the second electromagnetic radio wave frequency, the emission of a second set of control gradients comprising the emission of a first control gradient in the sagittal plane of the animal, a second control gradient in the dorsal plane of the animal, and a third control gradient in the transverse plane of the animal, the amplitude of the first, the second and third control gradients being identical and equal to a second gradient value allowing a diffusion between 0 s / mm2 and 50 s / mm2, preferably equal to 50 s / mm2 of the hydrogen atoms included in the second field of view, and

[0048] - after the echo duration beginning after the emission of the first wave radio frequency electromagnetic, the collection of a first control signal, the first control signal being representative of the magnetic field generated by each hydrogen atom in said section along the sagittal, dorsal and transverse planes of the animal, said hydrogen atom being excited by radio frequency electromagnetic waves and the first set of gradients and the second set of control gradients, the method further comprising:

[0049] or a reconstruction of a control set of three broadcast control images for each cut of the second set of cuts from the first control signal resulting from said cut, and

[0050] o a fusion of the diffusion control images of the second set of sections to obtain a second diffusion control image of the animal's body.

[0051] o the determination of a control map from the second diffusion image of the animal's body and the second control diffusion image of the animal's body.

[0052] Advantageously, the first animal body diffusion image and the second animal body diffusion image are merged to obtain a reconstructed animal body diffusion image.

[0053] Preferably, the method comprises the same number of anatomical steps as the number of diffusion sequence steps, an anatomical step being performed simultaneously with each diffusion sequence step to reconstruct an anatomical image of each slice of each group of slices, the anatomical images of each slice of each group of slices being superimposed with the corresponding diffusion image of the animal's body obtained from the first gradient value.

[0054] The invention further relates to a control device for a magnetic resonance imaging system for generating a diffusion image of an animal's body, in which:

[0055] - the device comprises a plurality of means configured to perform a first level of diffusion sequences in strict transverse acquisition with respiratory compensation of a first field of view, the size of the first field of view extending between 30 and 48 cm so that the animal's body is entirely included in the first field of view, the plurality of means including:

[0056] o acquisition means configured to acquire a first group of data slices of the animal contained in the first field of view along a transverse direction of the animal, the first group of data slices comprising slices of thickness between 2 and 6 mm,

[0057] o means for transmitting and receiving diffusion sequences in planar echo imaging configured, for each slice of the first set of slices, to emit a plurality of first excitation pulses separated from each other by a first repetition duration greater than 4500 ms and less than 10000 ms,

[0058] o each first excitation pulse comprising:

[0059] - the emission of a first electromagnetic radio frequency wave to put in phase the spins of the hydrogen protons contained in said cup,

[0060] - after an echo duration divided by two following the emission of the first radio frequency electromagnetic wave, the emission of a second radio frequency electromagnetic wave to compensate for the phase shift due to inhomogeneities in said section and simultaneously with the emission of the second radio frequency electromagnetic wave, the emission of a first set of gradients comprising the emission of a first gradient in the sagittal plane of the animal, a second gradient in the dorsal plane of the animal, and a third gradient in the transverse plane of the animal, the amplitude of the first, second and third gradients being identical and equal to a first gradient value allowing a scattering between 600 s / mm2 and 2000 s / mm2, preferably equal to 800 s / mm2 of the hydrogen atoms included in the first field of view, and

[0061] - after an echo duration beginning after the emission of the first wave radio frequency electromagnetic, the collection of a first resulting signal, the first signal being representative of the magnetic field generated by each hydrogen atom in said section along the sagittal, dorsal and transverse planes of the animal, said hydrogen atom being excited by radio frequency electromagnetic waves and the first set of gradients, the echo duration being between 45 ms and 100 ms,

[0062] o reconstruction means configured to reconstruct a first set of three broadcast images for each slice of the first set of slices from the first signal resulting from said slice, and

[0063] o of the first fusion means configured to fuse diffusion images from the first set of slices to obtain a first diffusion image of the animal's body.

[0064] Preferably, the plurality of means also includes:

[0065] o detection means configured to detect an expiratory plateau in the animal in order to determine the duration of the expiratory plateau and the respiratory rate, and

[0066] o of the first means of determination to choose the first repetition duration so that the second set of diffusion sequences is included in the expiratory plateau duration.

[0067] Advantageously, the detection means are configured to:

[0068] to identify sections from the first set of sections comprising at least partially the liver and lungs of the animal, and

[0069] o observe the displacement of the liver and lungs from the identified sections of the first set of sections,

[0070] the expiratory plateau duration and respiratory rate being determined from the relative displacement of the liver with respect to the lungs.

[0071] Preferably,

[0072] or the means for transmitting and receiving diffusion sequences in planar echo imaging are further configured to:

[0073] - simultaneously with the emission of the second electromagnetic radio wave frequency, emit a second set of control gradients comprising the emission of a first control gradient in the sagittal plane of the animal, a second control gradient in the dorsal plane of the animal, and a third control gradient in the transverse plane of the animal, the amplitude of the first, second, and third control gradients being identical and equal to a second gradient value allowing a diffusion between 0 s / mm2 and 50 s / mm2, preferably equal to 50 s / mm2 of the hydrogen atoms included in the first field of view, and

[0074] - after the echo duration beginning after the emission of the first wave radio frequency electromagnetic, collect a first control signal, the first control signal being representative of the magnetic field generated by each hydrogen atom in said section along the sagittal, dorsal and transverse planes of the animal, said hydrogen atom being excited by radio frequency electromagnetic waves and the first set of gradients and the second set of control gradients,

[0075] or the reconstruction means being further configured to reconstruct a control set of three broadcast control images for each cut of the first set of cuts from the first control signal resulting from said cut, and

[0076] o the first fusion means being further configured to fuse diffusion control images of the first set of sections to obtain a first diffusion control image of the animal's body,

[0077] or the device further comprising second determination means configured to determine a control map from of the first broadcast image of the animal's body and the first broadcast control image of the animal's body.

[0078] Preferably, if the size of the animal is greater than 48 cm so that the animal's body is not entirely included in the first field of view, the plurality of means are further configured to perform a second stage of diffusion sequences in strict transverse acquisition of a second field of view, the size of the second field of view extending between 30 and 48 cm and partially overlapping the first field of view, the first field of view covering a first area of ​​the animal delimited between the thorax and the abdomen of the animal to cover the pulmonary and abdominal areas of the animal, the second field of view covering a second area of ​​the animal delimited between the head and the shoulders of the animal or between the abdomen and the lower limbs of the animal so that the sum of the sizes of the fields of view of the stages of diffusion sequence is greater than or equal to the size of the animal,

[0079] o the acquisition means being further configured to acquire a second group of data slices of the animal contained within the field of view of the second level of diffusion sequences in a transverse direction of the animal, the second group of data slices comprising slices of equal thickness to the thickness of the slices of the first group of data slices,

[0080] o means for transmitting and receiving diffusion sequences in planar echo imaging being further configured, for each slice of the second set of slices, to emit a plurality of second excitation pulses separated from each other by a second repetition duration greater than 4500 ms and less than 10000 ms,

[0081] o each second excitation pulse comprising:

[0082] - the emission of the first radio frequency electromagnetic wave to put in phase the spins of the hydrogen protons contained in said section of the second set of sections,

[0083] - after the echo duration divided by two following the emission of the first radio frequency electromagnetic wave, the emission of the second radio frequency electromagnetic wave and simultaneously with the emission of the second radio frequency electromagnetic wave, the emission of the first set of gradients, and

[0084] - after the echo duration beginning after the emission of the first wave radio frequency electromagnetics, the collection of a second resulting signal, the second signal being representative of the magnetic field generated by each hydrogen atom in said section along the sagittal plane, the dorsal plane and the transverse plane of the animal, said hydrogen atom being excited by radio frequency electromagnetic waves and the first set of gradients,

[0085] o the reconstruction means being further configured to reconstruct a second set of three broadcast images for each cut of the second set of cuts from the second signal resulting from said cut, and

[0086] o the first fusion means being further configured to fuse images from the second set of slices to obtain a second diffusion image of the animal's body.

[0087] Advantageously:

[0088] or the means for transmitting and receiving diffusion sequences in planar echo imaging are further configured to:

[0089] - simultaneously with the emission of the second electromagnetic radio wave frequency, emit a second set of control gradients comprising the emission of a first control gradient in the sagittal plane of the animal, a second control gradient in the dorsal plane of the animal, and a third control gradient in the transverse plane of the animal, the amplitude of the first, second, and third control gradients being identical and equal to a second gradient value allowing a diffusion between 0 s / mm2 and 50 s / mm2, preferably equal to 50 s / mm2 of the hydrogen atoms included in the second field of view, and

[0090] - after the echo duration beginning after the emission of the first wave radio frequency electromagnetic, collect a first control signal, the first control signal being representative of the magnetic field generated by each hydrogen atom in said section along the sagittal, dorsal and transverse planes of the animal, said hydrogen atom being excited by radio frequency electromagnetic waves and the first set of gradients and the second set of control gradients,

[0091] o the reconstruction means being further configured to reconstruct a control set of three broadcast control images for each cut of the second set of cuts from the first control signal resulting from said cut, and

[0092] o the first fusion means being further configured to fuse diffusion control images of the second set of sections to obtain a second diffusion control image of the animal's body,

[0093] or the device further comprising second determination means configured to determine a determination of a control map from the second diffusion image of the animal's body and the second control diffusion image of the animal's body.

[0094] Preferably, the device further comprises second fusion means configured to fuse the first animal body diffusion image and the second animal body diffusion image to obtain a reconstructed animal body diffusion image.

[0095] Advantageously, the device comprises:

[0096] o control means configured to perform the same number of anatomical steps as the number of diffusion sequence steps, one anatomical step being performed simultaneously with each diffusion sequence step to reconstruct an anatomical image of each slice in each group of slices, and

[0097] o superposition means configured to superimpose the anatomical images of each slice of each group of slices with the corresponding diffusion image of the animal's body obtained from the first gradient value.

[0098] The invention further relates to a magnetic resonance imaging system comprising a magnetic resonance imaging system and a control device as defined above connected to the magnetic resonance imaging system.

[0099] Other objects, features and advantages of the invention will become apparent from the following description, given solely by way of non-limiting example, and made with reference to the accompanying drawings in which:

[0100] [Fig.l]

[0101] schematically illustrates an example of a magnetic resonance imaging system according to the invention;

[0102] [Fig.2]

[0103] schematically illustrates an example of the implementation of a control device according to the invention;

[0104] [Fig.3]

[0105] schematically illustrates a first example of a magnetic resonance imaging method according to the invention; and

[0106] [Fig.4]

[0107] schematically illustrates a second example of a magnetic resonance imaging method according to the invention.

[0108] Fig. 1 schematically illustrates an example of a magnetic resonance imaging assembly 1 comprising a magnetic resonance imaging system 2 and a control device 3 connected to said system 2.

[0109] The magnetic resonance imaging system 1 includes an examination tunnel 4, a table 5 intended to be inserted into the examination tunnel 4 to perform an MRI magnetic resonance imaging examination.

[0110] An animal 6 is positioned and held on the table 5 to perform an MRI magnetic resonance imaging examination, for example of the spine of a dog.

[0111] Animal 6 can be a dog, a cat or any other animal.

[0112] The animal 6 is for example positioned and held by a holding device 7 on the table 5.

[0113] A permanent static magnetic field is applied in the magnetic resonance imaging system 2, the value of the static magnetic field being for example greater than 0.55 Tesla, preferably equal to 1.5 Tesla, more preferably equal to 3 Tesla.

[0114] Fig. 2 schematically illustrates an example of an embodiment of the control device 3.

[0115] The control device 3 includes acquisition means 8, transmission and reception means 9 of diffusion sequences in planar echo imaging, detection means 10, first determination means 11, second determination means 12, reconstruction means 13, first fusion means 14, second fusion means 15, control means 16, and superposition means 17.

[0116] Fig. 3 schematically illustrates a first example of a magnetic resonance imaging process for generating a diffusion image of an animal body 6.

[0117] The method implements the imaging assembly 1.

[0118] In this example, it is assumed that the size of the animal 6 is such that the body of the animal 6 is entirely included in a first field of view of the magnetic resonance imaging system 2 extending between 30 and 48 cm.

[0119] A first stage of diffusion sequences in strict transverse acquisition with respiratory compensation of the first field of view is carried out.

[0120] The first stage of diffusion sequences comprises a first set of localization sequences, a second set of diffusion sequences in echo planar imaging “echo planar imaging EPI”.

[0121] During a step 20 of obtaining the first set of spotting sequences, the acquisition means 8 acquire a first group of data slices of the animal 6 contained in the first field of view along a transverse direction of the animal.

[0122] The first group of data slices comprises slices with a thickness between 2 and 6 mm.

[0123] During a step 21, the detection means 10 detect an expiratory plateau of the animal 6 to determine the duration of the expiratory plateau and the respiratory rate, and the first determination means 11 choose the first repetition duration so that the second set of diffusion sequences is included in the expiratory plateau duration.

[0124] The first repetition duration is greater than 4500 ms and less than 10000 ms.

[0125] To determine the expiratory plateau duration and respiratory rate, the detection means 10 identify sections from the first set of sections comprising at least partially the liver and lungs of the animal 6.

[0126] The detection means 10 observe the displacement of the liver and lungs from the identified sections of the first set of sections.

[0127] The expiratory plateau duration and respiratory rate are determined from the relative displacement of the liver with respect to the lungs.

[0128] Alternatively, the process does not include step 21, the process continuing directly to a step 22 after the execution of step 20.

[0129] During step 22 of obtaining the second set of diffusion sequences in planar echo imaging, the transmitting and receiving means 9 control the magnetic resonance imaging system 2 so that for each slice of the first set of slices, a plurality of first excitation pulses separated from each other of the first repetition duration, and collects and transmits to the transmitting and receiving means 9 a first resulting signal.

[0130] If the process does not include step 21, the first repetition time is greater than 4500 ms and less than 10000 ms, and is determined according to the number of cuts included in the first step.

[0131] The first repetition duration is, for example, determined by an algorithm known from the prior art.

[0132] Each first excitation pulse comprises:

[0133] - the emission of a first electromagnetic radio frequency wave to put in phase the spins of the hydrogen protons contained in said cup,

[0134] - after an echo duration divided by two following the emission of the first radio frequency electromagnetic wave, the emission of a second radio frequency electromagnetic wave to compensate for the phase shift due to inhomogeneities in said section and simultaneously with the emission of the second radio frequency electromagnetic wave, the emission of a first set of gradients comprising the emission of a first gradient in the sagittal plane of the animal, a second gradient in the dorsal plane of the animal, and a third gradient in the transverse plane of the animal, the amplitude of the first, second and third gradients being identical and equal to a first gradient value allowing a scattering between 600 s / mm2 and 2000 s / mm2, preferably equal to 800 s / mm2 of the hydrogen atoms included in the first field of view, and

[0135] - after an echo duration beginning after the emission of the first wave radio frequency electromagnetic, the collection of the first resulting signal, the first resulting signal being representative of the magnetic field generated by each hydrogen atom in said section along the sagittal, dorsal and transverse planes of the animal, said hydrogen atom being excited by radio frequency electromagnetic waves and the first set of gradients, the echo duration being between 45 ms and 100 ms.

[0136] During a step 23, the reconstruction means 13 reconstruct a first set of three diffusion images for each slice of the first set of slices from the first signal resulting from said slice.

[0137] During a step 24, the first fusion means 14 fuse diffusion images from the first set of slices to obtain a first diffusion image of the animal's body 6.

[0138] Since the body trail of animal 6 is integrated into the first field of view, the first diffusion image of the body of animal 6 is a diffusion image of the whole body of animal 6.

[0139] The spatial resolution of the whole-body diffusion image of the animal 6 is improved compared to known prior art MRI imaging in which the fields of view are reduced and the spatial resolution is increased when examining the body of an animal.

[0140] The first stage of diffusion sequences acquired in strict transverse acquisition makes it possible to reduce eddy currents, reduce Nyquist artifacts and simplify registration.

[0141] Respiratory compensation helps to limit as much as possible the artifacts related to the movements of the animal's respiration 6.

[0142] Emitting a plurality of first excitation sequences having the first gradient value between 600 s / mm2 and 2000 s / mm2, preferably equal to 800 s / mm2 by the transmission and reception means 9 makes it possible to increase the signal-to-noise ratio of the first signal resulting from each cut.

[0143] During step 22 of obtaining the second set of diffusion sequences in planar echo imaging, the transmitting and receiving means 9 can further control the magnetic resonance imaging system 2 so that it emits a control excitation sequence simultaneously with each emission of a first excitation, and collects and transmits to the transmitting and receiving means 9 a first control signal.

[0144] Each control excitation sequence comprises:

[0145] - simultaneously with the emission of the second electromagnetic radio wave frequency, the emission of a second set of control gradients comprising the emission of a first control gradient in the sagittal plane of the animal, a second control gradient in the dorsal plane of the animal, and a third control gradient in the transverse plane of the animal, the amplitude of the first, second, and third control gradients being identical and equal to a second gradient value allowing a diffusion between 0 s / mm2 and 50 s / mm2, preferably equal to 50 s / mm2 of the hydrogen atoms included in the first field of view, and

[0146] - after the echo duration beginning after the emission of the first wave radio frequency electromagnetic, the collection of the first control signal, the first control signal being representative of the magnetic field generated by each hydrogen atom in said section along the sagittal, dorsal and transverse planes of the animal, said hydrogen atom being excited by radio frequency electromagnetic waves and the first set of gradients and the second set of control gradients.

[0147] If step 22 includes the emission of control excitation sequences, during a step 25, the reconstruction means 13 reconstruct a control set of three diffusion control images for each slice of the first set of slices from the first control signal resulting from said slice.

[0148] During a step 26 the first fusion means 14 fuse diffusion control images of the first set of sections to obtain a first diffusion control image of the animal's body, and during a step 27, the second determination means 12 determine a first control map from the first diffusion image of the animal's body and the first diffusion control image of the animal's body.

[0149] The first control map includes diffusion coefficients to filter the first diffusion image of the animal's body to exclude areas resembling "false positive" lesions. The first control map is, for example, an apparent diffusion coefficient (ADC) type map.

[0150] The method may include a step 28 during which the control means 16 control the magnetic resonance imaging system 2 so that it performs the same number of anatomical steps as the number of diffusion sequence steps.

[0151] An anatomical step as known from the prior art is performed simultaneously with the first step of diffusion sequences to reconstruct an anatomical image of each slice of the first group of slices.

[0152] The anatomical images represent tissues of animal 6.

[0153] The anatomical images of each section of the first group of sections are superimposed by the superposition means 17 with the corresponding diffusion image of the animal's body obtained from the first gradient value.

[0154] The superimposed image obtained makes it possible to locate a lesion appearing on a diffusion image of the animal's body in the foreground of view in relation to the animal's bone structure 6.

[0155] Fig. 4 schematically illustrates a second example of the magnetic resonance imaging process for generating a diffusion image of an animal body 6.

[0156] In this example, it is assumed that the size of the animal 6 is such that the whole body of the animal 6 extends beyond the first field of view of the magnetic resonance imaging system 2 extending between 30 and 48 cm.

[0157] The size of animal 6 is divided into sections between 30 cm and 48 cm, each section being subjected to a level of diffusion sequences in strict transverse acquisition with or without respiratory compensation so that animal 6 is included in several fields of view.

[0158] It is assumed that the method comprises the first stage of diffusion sequences in strict transverse acquisition with respiratory compensation of the first field of view and a second stage of diffusion sequences in strict transverse acquisition of a second field of view.

[0159] Of course, the process may include more than two stages of diffusion sequences in strict transverse acquisition.

[0160] The first field of view of the first stage covers a first area of ​​the animal delimited between the thorax and the abdomen of the animal to cover the pulmonary and abdominal areas of the animal.

[0161] The size of the second field of view of the second stage of diffusion sequences extends between 30 and 48 cm and partially overlaps the first field of view.

[0162] The second field of view of the second stage of diffusion sequences covers a second area of ​​the animal delimited between the head and shoulders of the animal or between the abdomen and lower limbs of the animal such that the sum of the size of the fields of view of the stages of diffusion sequence is greater than or equal to the size of the animal 6.

[0163] The second level of diffusion sequences includes a third set of localization sequences, a fourth set of diffusion sequences in echo planar imaging EPI.

[0164] It is assumed that the first step is completed before the second step.

[0165] Alternatively, the second step is carried out before the first step.

[0166] We find steps 20 and 22 to 28 described previously (first stage of diffusion sequence), step 21 being optional.

[0167] Then, during a step 29, of obtaining the third set of spotting sequences, the acquisition means 8 acquire a second group of data slices of the animal 6 contained in the second field of view along a transverse direction of the animal.

[0168] The second group of data slices comprises slices of equal thickness to the thickness of the slices in the first group of data slices.

[0169] During a step 30 of obtaining the fourth set of diffusion sequences in planar echo imaging, the transmitting and receiving means 9 control the magnetic resonance imaging system 2 so that it emits, for each slice of the second set of slices, a plurality of second excitation pulses separated from each other by a second repetition duration, and collects and transmits to the transmitting and receiving means 9 the first resulting signal.

[0170] The second repetition duration is greater than 4500 ms and less than 10000 ms.

[0171] The second repetition duration is defined according to the number of cuts included in each level.

[0172] The second repetition duration is, for example, determined by an algorithm known from the prior art.

[0173] Each second excitation pulse comprises:

[0174] - the emission of the first electromagnetic radio frequency wave,

[0175] - after the echo duration divided by two following the emission of the first radio frequency electromagnetic wave, the emission of the second radio frequency electromagnetic wave and simultaneously with the emission of the second radio frequency electromagnetic wave, the emission of the first set of gradients, and

[0176] - after the echo duration following the emission of the first electromagnetic wave radio frequency, the collection of a second resulting signal, the second resulting signal being representative of the magnetic field generated by each hydrogen atom in said section along the sagittal, dorsal and transverse planes of the animal, said hydrogen atom being excited by radio frequency electromagnetic waves and the first set of gradients.

[0177] During a step 31, the reconstruction means 13 reconstruct a second set of three diffusion images for each cut of the second set of cuts from the second signal resulting from said cut.

[0178] During a step 32, the first fusion means 14 fuse diffusion images from the second set of slices to obtain a second diffusion image of the animal's body 6.

[0179] During step 30 of obtaining the fourth set of diffusion sequences in planar echo imaging, the transmitting and receiving means 9 may further control the magnetic resonance imaging system 2 so that it emits the control excitation sequence simultaneously with each emission of a second excitation, and collects and transmits to the transmitting and receiving means 9 the first control signal.

[0180] If step 30 includes the emission of control excitation sequences, during a step 31, the reconstruction means 13 reconstruct the control set of three diffusion control images for each slice of the second set of slices from the first control signal resulting from said slice.

[0181] During a step 33, the first fusion means 14 fuse diffusion control images of the second set of sections to obtain a second diffusion control image of the animal body, and during a step 34, the second determination means 12 determine a second control map from the second diffusion image of the animal body and the second diffusion control image of the animal body.

[0182] The second control map includes diffusion coefficients to filter the second diffusion image of the animal's body to exclude areas resembling "false positive" lesions. The second control map is, for example, an apparent diffusion coefficient (ADC) type map.

[0183] The method may include a step 35 during which the control means 16 control the magnetic resonance imaging system 2 so that it performs an anatomical step as known from the prior art simultaneously with the second step of diffusion sequences to reconstruct an anatomical image of each slice of the second group of slices.

[0184] The anatomical images represent tissues of animal 6.

[0185] The anatomical images of each section of the second group of sections are superimposed by the superposition means 17 with the corresponding diffusion image of the animal's body obtained from the first gradient value.

[0186] The superimposed image obtained makes it possible to locate a lesion appearing on a diffusion image of the animal's body in the second plane of view in relation to the bone structure of the animal 6.

[0187] During a step 36, the second fusion means 15 fuse the first animal body diffusion image and the second animal body diffusion image to obtain a reconstructed animal body diffusion image.

[0188] If the body of animal 6 is contained in the first animal body diffusion image and the second animal body diffusion image, the reconstructed animal body diffusion image is a whole body diffusion image of animal 6.

[0189] If more than two levels of diffusion sequences are required depending on the size of the animal 6, the second fusion means 15 fuse all the diffusion images of the animal's body obtained to obtain a whole-body diffusion image of the animal 6.

[0190] The first fusion means 14 and the second fusion means 15 implement known image fusion algorithms.

[0191] The superposition means 17 implement known image superposition algorithms.

[0192] The frequency of the first and second radio frequency electromagnetic waves is determined according to the amplitude of the static magnetic field.

[0193] For example, when the amplitude of the static magnetic field is equal to 0.55 Tesla, the frequency of the first and second electromagnetic waves is approximately 23.5 MHz; when the amplitude of the static magnetic field is equal to 1.5 Tesla, the frequency of the first and second electromagnetic waves is approximately 64 MHz; and when the amplitude of the static magnetic field is equal to 3 Tesla, the frequency of the first and second electromagnetic waves is approximately 128 MHz. Each level of diffusion sequences allows the diffusion of water molecules from the body of the animal 6 included in the field of view associated with said level of diffusion sequences.

Claims

1. Demands A magnetic resonance imaging method for generating a diffusion image of an animal body (6) comprising: - ,a first stage of diffusion sequences in strict transverse acquisition with respiratory compensation of a first field of view, the size of the first field of view extending between 30 and 48 cm so that the animal's body is entirely included in the first field of view, the first stage of diffusion sequences comprising: • a first set of tracking sequences comprising the acquisition of a first group of data slices of the animal (6) contained in the first field of view along a transverse direction of the animal (6), the first group of data slices comprising slices of thickness between 2 and 6 mm, • a second set of diffusion-weighted planar echo imaging sequences comprising, for each slice of the first set of slices, the emission of a plurality of first excitation pulses separated from each other by a first repetition duration greater than 4500 ms and less than 10000 ms, • each first excitation pulse comprising: - the emission of a first electromagnetic radio frequency wave to phase the spins of the hydrogen protons contained in said cup, - after an echo duration halved following the emission of the first radio frequency electromagnetic wave, the emission of a second radio frequency electromagnetic wave to compensate for the phase shift due to inhomogeneities in said section, and simultaneously with the emission of the second radio frequency electromagnetic wave, the emission of a first set of gradients comprising the emission of a first gradient in the sagittal plane of the animal, a second gradient in the dorsal plane of the animal, and a third gradient in the transverse plane of the animal, the amplitude of the first, second and third gradients being identical and equal to a first gradient value allowing a scattering of between 600 s / mm2 and 2000 s / mm2, preferably equal to 800 s / mm2 of the hydrogen atoms included in the first field of view, and - after an echo duration beginning after the emission of the first radio frequency electromagnetic wave, the collection of a first resulting signal, the first signal being representative of the magnetic field generated by each hydrogen atom in said section along the sagittal, dorsal and transverse planes of the animal (6), said hydrogen atom being excited by the radio frequency electromagnetic waves and the first set of gradients, the echo duration being between 45 ms and 100 ms,• a reconstruction of a first set of three diffusion images for each slice of the first set of slices from the first signal resulting from said slice, and • a fusion of the diffusion images of the first set of slices to obtain a first diffusion image of the animal's body.

2. A method according to claim 1, wherein the first stage of diffusion sequences further includes the detection of an expiratory plateau of the animal (6) to determine the duration of the expiratory plateau and the respiratory rate, the first repetition duration being chosen so that the second set of diffusion sequences is included in the duration of the expiratory plateau.

3. A method according to claim 2, wherein the determination of the expiratory plateau time and respiratory rate comprises:

4. • an identification of the sections from the first set of sections comprising at least partially the liver and lungs of the animal (6), and • an observation of the displacement of the liver and lungs from the identified sections of the first set of sections, the duration of the expiratory plateau and the respiratory rate being determined from the relative displacement of the liver with respect to the lungs. A method according to any one of claims 1 to 3, wherein the second set of diffusion sequences further comprises the emission of a control excitation sequence simultaneously with each emission of a first excitation pulse, each control excitation sequence comprising: - simultaneously with the emission of the second radio frequency electromagnetic wave, the emission of a second set of control gradients comprising the emission of a first control gradient in the sagittal plane of the animal (6), a second control gradient in the dorsal plane of the animal (6), and a third control gradient in the transverse plane of the animal (6), the amplitude of the first, second, and third control gradients being identical and equal to a second gradient value allowing a scattering between 0 s / mm2 and 50 s / mm2, preferably equal to 50 s / mm2 of the hydrogen atoms included in the first field of view, and - after the echo duration beginning after the emission of the first radio frequency electromagnetic wave, the collection of a first control signal, the first control signal being representative of the magnetic field generated by each hydrogen atom in said section along the sagittal, dorsal and transverse planes of the animal, said hydrogen atom being excited by the radio frequency electromagnetic waves and the first set of gradients and the second set of control gradients, the process also including:

5. • a reconstruction of a control set of three broadcast control images for each cut of the first set of cuts from the first control signal resulting from said cut, • a fusion of the diffusion control images from the first set of slices to obtain a first diffusion control image of the animal's body, and • the determination of a control map from the first diffusion image of the animal's body (6) and the first control diffusion image of the animal's body (6). A method according to any one of claims 1 to 4, wherein if the size of the animal (6) is greater than 48 cm such that the body of the animal is not entirely included in the first field of view, the method comprises the first stage of diffusion sequences and furthermore at least a second stage of diffusion sequences in strict transverse acquisition of a second field of view, the size of the second field of view extending between 30 and 48 cm and partially covering the first field of view, the first field of view covering a first area of ​​the animal delimited between the thorax and the abdomen of the animal (6) to cover the pulmonary and abdominal areas of the animal (6),the second field of view covering a second area of ​​the animal delimited between the head and shoulders of the animal (6) or between the abdomen and lower limbs of the animal such that the sum of the sizes of the fields of view of the diffusion sequence levels is greater than or equal to the size of the animal (6), the second diffusion sequence level comprising:, • a third set of tracking sequences comprising the acquisition of a second group of data slices of the animal (6) contained in the field of view of the second level of diffusion sequences along a transverse direction of the animal (6), the second group of data slices comprising slices of equal thickness to the thickness of the slices of the first group of data slices,

6. • a fourth set of diffusion-weighted planar echo imaging sequences comprising, for each slice of the second set of slices, the emission of a plurality of second excitation pulses separated from each other by a second repetition duration greater than 4500 ms and less than 10000 ms, • each second excitation pulse comprising: - the emission of the first radio frequency electromagnetic wave to phase the spins of the hydrogen protons contained in said section of the second set of sections, - after the echo duration is halved following the emission of the first radio frequency electromagnetic wave, the emission of the second radio frequency electromagnetic wave and simultaneously with the emission of the second radio frequency electromagnetic wave, the emission of the first set of gradients, and - after the echo duration beginning after the emission of the first radio frequency electromagnetic wave, the collection of a second resulting signal, the second signal being representative of the magnetic field generated by each hydrogen atom in said section along the sagittal, dorsal and transverse planes of the animal (6), said hydrogen atom being excited by the radio frequency electromagnetic waves and the first set of gradients, • a reconstruction of a second set of three broadcast images for each slice of the second set of slices from the second signal resulting from said slice, and • a fusion of the images from the second set of slices to obtain a second diffusion image of the animal's body (6). A method according to claim 5, wherein the fourth set of diffusion sequences further comprises the emission of a control excitation sequence simultaneously with each emission of a second excitation pulse, each control excitation sequence comprising: - simultaneously with the emission of the second radio frequency electromagnetic wave, the emission of a second set of control gradients comprising the emission of a first control gradient in the sagittal plane of the animal (6), a second control gradient in the dorsal plane of the animal, and a third control gradient in the transverse plane of the animal (6), the amplitude of the first, second and third control gradients being identical and equal to a second gradient value allowing a scattering between 0 s / mm2 and 50 s / mm2, preferably equal to 50 s / mm2 of the hydrogen atoms included in the second field of view, and - after the echo duration beginning after the emission of the first radio frequency electromagnetic wave, the collection of a first control signal, the first control signal being representative of the magnetic field generated by each hydrogen atom in said section along the sagittal, dorsal and transverse planes of the animal (6), said hydrogen atom being excited by the radio frequency electromagnetic waves and the first set of gradients and the second set of control gradients, the process also including: • a reconstruction of a control set of three broadcast control images for each cut of the second set of cuts from the first control signal resulting from said cut, and • a fusion of diffusion control images from the second set of slices to obtain a second diffusion control image of the animal body (6). • the determination of a control map from the second diffusion image of the animal's body (6) and the second control diffusion image of the animal's body (6).

7. A method according to claim 5 or 6, wherein the first animal body diffusion image (6) and the second animal body diffusion image (6) are merged to obtain a reconstructed animal body diffusion image (6).

8. A method according to any one of claims 1 to 6, comprising the same number of anatomical steps as the number of diffusion sequence steps, an anatomical step being performed simultaneously with each diffusion sequence step to reconstruct an anatomical image of each slice of each group of slices, the anatomical images of each slice of each group of slices being superimposed with the corresponding diffusion image of the animal's body obtained from the first gradient value.

9. Control device (3) for a magnetic resonance imaging system (1) for generating a diffusion image of the body of an animal (6), wherein: - the device comprises a plurality of means (8, 9, 12, 13, 14, 15, 16, 17) configured to perform a first stage of diffusion sequences in strict transverse acquisition with respiratory compensation of a first field of view, the size of the first field of view extending between 30 and 48 cm so that the body of the animal is entirely included in the first field of view, the plurality of means comprising: • acquisition means (8) configured to acquire a first group of data slices of the animal (6) contained in the first field of view along a transverse direction of the animal (6), the first group of data slices comprising slices of thickness between 2 and 6 mm,• means for transmitting and receiving (9) diffusion sequences in planar echo imaging configured, for each slice of the first set of slices, to emit a plurality of first excitation pulses separated from each other by a first repetition duration greater than 4500 ms and less than 10000 ms, • each first excitation pulse comprising:, the emission of a first radio frequency electromagnetic wave to phase the spins of the hydrogen protons contained in said section, after an echo time divided by two following the emission of the first radio frequency electromagnetic wave, the emission of a second radio frequency electromagnetic wave to compensate for the phase shift linked to inhomogeneities in said section and simultaneously with the emission of the second radio frequency electromagnetic wave, the emission of a first set of gradients comprising the emission of a first gradient in the sagittal plane of the animal (6), a second gradient in the dorsal plane of the animal (6), and a third gradient in the transverse plane of the animal (6), the amplitude of the first, second and third gradients being identical and equal to a first gradient value allowing a diffusion between 600 s / mm2 and 2000 s / mm2,preferably equal to 800 s / mm2 of hydrogen atoms included in the first field of view, and, after an echo duration beginning after the emission of the first radio frequency electromagnetic wave, the collection of a first resulting signal, the first signal being representative of the magnetic field generated by each hydrogen atom in said section along the sagittal, dorsal and transverse planes of the animal (6), said hydrogen atom being excited by the radio frequency electromagnetic waves and the first set of gradients, the echo duration being between 45 ms and 100 ms, reconstruction means (13) configured to reconstruct a first set of three broadcast images for each cut of the first set of cuts from the first signal resulting from said cut, and of the first fusion means (14) configured to fuse diffusion images from the first set of slices to obtain a first diffusion image of the animal's body.

10. Device according to claim 9, wherein the plurality of means (8, 9, 12, 13, 14, 15, 16, 17) further comprises: • detection means (10) configured to detect an expiratory plateau of the animal (6) to determine the duration of the expiratory plateau and the respiratory rate, and • first determination means (11) to choose the first repetition duration so that the second set of diffusion sequences is included in the duration of the expiratory plateau.

11. Device according to claim 10, wherein the sensing means (10) are configured to: • identify sections from the first set of sections comprising at least partially the liver and lungs of the animal (6), and • observe the displacement of the liver and lungs from the identified sections of the first set of sections, the expiratory plateau time and respiratory rate being determined from the relative displacement of the liver with respect to the lungs.

12. A device according to any one of claims 9 to 11, wherein: • the means for transmitting and receiving (9) scatter sequences in planar echo imaging are further configured to: - simultaneously with the emission of the second radio frequency electromagnetic wave, emit a second set of control gradients comprising the emission of a first control gradient in the sagittal plane of the animal (6), a second control gradient in the dorsal plane of the animal (6), and a third control gradient in the transverse plane of the animal (6), the amplitude of the first, second, and third control gradients being identical and equal to a second gradient value allowing scattering between 0 s / mm² and 50 s / mm², preferably equal to 50 s / mm², of the hydrogen atoms included in the first field of view, and

13. - after the echo duration beginning after the emission of the first radio frequency electromagnetic wave, collect a first control signal, the first control signal being representative of the magnetic field generated by each hydrogen atom in said section along the sagittal, dorsal and transverse planes of the animal (6), said hydrogen atom being excited by the radio frequency electromagnetic waves and the first set of gradients and the second set of control gradients, • the reconstruction means (13) being further configured to reconstruct a control set of three broadcast control images for each cut of the first set of cuts from the first control signal resulting from said cut, and • the first fusion means (14) being further configured to fuse diffusion control images of the first set of sections to obtain a first diffusion control image of the animal body (6), • the device (3) further comprising second determination means (12) configured to determine a determination of a control map from the first diffusion image of the animal's body (6) and the first control diffusion image of the animal's body (6). A device according to any one of claims 9 to 12, wherein if the size of the animal (6) is greater than 48 cm such that the animal's body is not entirely included in the first field of view, the plurality of means (9, 12, 3, 14, 15, 16, 17) are further configured to perform a second stage of diffusion sequences in strict transverse acquisition of a second field of view, the size of the second field of view extending between 30 and 48 cm and partially overlapping the first field of view, the first field of view covering a first area of ​​the animal (6) delimited between the thorax and abdomen of the animal (6) to cover the pulmonary and abdominal areas of the animal (6), the second field of view covering a second area of ​​the animal (6) delimited between the head and shoulders of the animal or between the abdomen and lower limbs of the animal (6) such that the sum of the sizes of the fields of view of the diffusion sequence levels is greater than or equal to the size of the animal (6), • the acquisition means (8) being further configured to acquire a second group of data slices of the animal (6) contained in the field of view of the second level of diffusion sequences along a transverse direction of the animal (6), the second group of data slices comprising slices of equal thickness to the thickness of the slices of the first group of data slices, • means for transmitting and receiving (9) diffusion sequences in planar echo imaging being further configured, for each slice of the second set of slices, to emit a plurality of second excitation pulses separated from each other by a second repetition duration greater than 4500 ms and less than 10000 ms, • each second excitation pulse comprising: - the emission of the first radio frequency electromagnetic wave to phase the spins of the hydrogen protons contained in said section of the second set of sections, - after the echo duration is halved following the emission of the first radio frequency electromagnetic wave, the emission of the second radio frequency electromagnetic wave and simultaneously with the emission of the second radio frequency electromagnetic wave, the emission of the first set of gradients, and - after the echo duration beginning after the emission of the first radio frequency electromagnetic wave, the collection of a second resulting signal, the second signal being representative of the magnetic field generated by each hydrogen atom in said section along the planes sagittal, dorsal and transverse of the animal (6), said hydrogen atom being excited by radio frequency electromagnetic waves and the first set of gradients, • the reconstruction means being further configured to reconstruct a second set of three diffusion images for each slice of the second set of slices from the second signal resulting from said slice, and • the first fusion means being further configured to fuse images of the second set of slices of the second set of slices to obtain a second diffusion image of the animal's body (6).

14. Device according to claim 13, wherein: • the means for transmitting and receiving (9) scatter sequences in planar echo imaging are further configured to: - simultaneously with the emission of the second radio frequency electromagnetic wave, emit a second set of control gradients comprising the emission of a first control gradient in the sagittal plane of the animal (6), a second control gradient in the dorsal plane of the animal (6), and a third control gradient in the transverse plane of the animal (6), the amplitude of the first, second, and third control gradients being identical and equal to a second gradient value allowing scattering between 0 s / mm2 and 50 s / mm2, preferably equal to 50 s / mm2 of the hydrogen atoms included in the second field of view, and - after the echo duration beginning after the emission of the first radio frequency electromagnetic wave,to collect a first control signal, the first control signal being representative of the magnetic field generated by each hydrogen atom in said section along the sagittal, dorsal and transverse planes of the animal (6), said hydrogen atom being excited by radio frequency electromagnetic waves and the first, set of gradients and the second set of control gradients, • the reconstruction means (13) being further configured to reconstruct a control set of three diffusion control images for each slice of the second set of slices from the first control signal resulting from said slice, and • the first fusion means (14) being further configured to fuse diffusion control images from the second set of slices to obtain a second diffusion control image of the animal body (6), • the device (3) further comprising second determination means (12) configured to determine a determination of a control map from the second diffusion image of the animal body (6) and the second diffusion control image of the animal body (6).

15. Device according to claim 13 or 14, further comprising second fusion means (15) configured to fuse the first animal body diffusion image (6) and the second animal body diffusion image (6) to obtain a reconstructed animal body diffusion image (6).

16. A device according to any one of claims 9 to 15, comprising: • control means (16) configured to perform the same number of anatomical steps as the number of diffusion sequence steps, an anatomical step being performed simultaneously with each diffusion sequence step to reconstruct an anatomical image of each slice of each group of slices, and • superposition means (17) configured to superimpose the anatomical images of each slice of each group of slices with the corresponding diffusion image of the animal's body (6) obtained from the first gradient value.

17. Magnetic resonance imaging assembly (1) comprising a magnetic resonance imaging system (2) and a device (3) control according to any one of claims 9 to 16 related to the magnetic resonance imaging system (2).

Images