Segmentation of magnetic resonance using transmission data when forming hybrid nuclear/magnetic resonance images. RU patent 2504841.

FIELD: physics.

SUBSTANCE: system (10) for correcting anatomical images includes: a magnetic resonance (MR) imager (12) which obtains MR image data (14) of a subject (60) during scanning to collect MR data; a nuclear scanner (20) which obtains nuclear image data (23) of a subject (60) during scanning to collect nuclear data, and simultaneously measures transmission data (22) from a radiation source (18) located in the investigation region of the nuclear scanner (20); and a processor which: generates an attenuation correction (AC) map (16) from the MR image data (14); iteratively adjusts the AC map (16) to form an improved AC map (32) using the measured transmission data (22); and makes corrections to image nuclear data (23) based on attenuation using the improved AC map (32).

EFFECT: ensuring accuracy of the attenuation correction map, eliminating the uncertainty between air elements of the three-dimensional image and bone elements of the three-dimensional image in a magnetic resonance-based attenuation correction map.

15 cl, 5 dwg

The present invention has particular application in the systems of formation anatomical image, more accurately, including the formation of a combined images PET-MR (positron emission tomography - nuclear resonance), but may also find application in other systems for building nuclear images, and the like. However, it should be noted that the described technique can also be used in other systems, imaging, other scenarios imaging, other techniques for the analysis of the images, and the like.

Imaging, positron emission tomography (PET), attenuation data PET usually adjusted using the card attenuation. During the formation of combined PET images - computer tomography (CT)data CT can easily create accurate map of the decay for data PET. Data and images CT based on the properties of the attenuation of radiation have been subjected to the formation of images of tissues. However, the formation of combined PET images magnetic resonance (MR)images MR depict the characteristics of resonance, typically, dipoles (H 1 )that are not a function of the properties of attenuation of the radiation of the patient.

PET scanners are typically combined with CT scanner, and most recently, with the scanner MR. The image can give MR map that depicts the anatomical organs or segmented region similar tissue type. For example, the image of MR usually shows a bone as a dark area, which can cause problems in distinguishing the bones from the air, which is also shown as a dark area. Air and bone have very different properties in respect of the attenuation of radiation. Bone structure, as a rule, includes the cortical layer of bone or shell on the surface and a porous, spongy bone inside. Understanding the anatomy of a typical it is necessary to distinguish between the bone and air areas. Note that if cortical shell is adjacent to an air pocket, MR image could show both as a single dark area. Therefore layer of the bone may be set to an incorrect value (for example, a value that is compatible with the air) on the map attenuation, or Vice versa. Technology for segmentation of areas of the cortical bone layer exist but are not always reliable.

This application provides new and improved the system and how to Refine based on MR card attenuation correction to correct for attenuation in the nuclear image, which overcome the above mentioned and other problems.

In accordance with one of the aspects of the correction system anatomical image includes the imaging unit of magnetic resonance (MR), which retrieves the image data MR subject during scanning for data collection MR, and nuclear scanner that gets nuclear data image of the subject during the scan for nuclear data collection, and simultaneously measures the data bandwidth from the radiation source located in the area of nuclear research of the scanner. System also includes a processor that generates a map attenuation correction (AC) from the image data MR, iteratively clarifies the map AC to form an updated map AC, with the use of measured data transmission, and amends the nuclear data image with the attenuation using the elaborated card AC.

In accordance with another aspect way to Refine card attenuation correction (AC) magnetic resonance (MR) includes the formation of the card attenuation correction (AC) from the image of MR subject transmission of radiation from the source of radiation through the subject of the radiation source is located outside the territory, and measurement data bandwidth radiation passed through the subject. A way of additionally includes the formation of the evaluated data bandwidth from the map AC and organize the specified card AC via the settings of the card AC on the basis of comparison of measured data transmission and evaluated data bandwidth.

In accordance with another aspect, PET scanner includes the ring radiation detectors, radiation source, motionless mounted within ring radiation detectors, and the processor is programmed to complete method under paragraph 1 in order to form an updated map attenuation correction (AC). The scanner also includes reconstruction algorithm, which corrects the data PET of radiation detectors elaborated card AC and reconstructs the corrected data PET subjected attenuation correction image of the PET.

In accordance with another aspect of the device to clarify card attenuation correction to correct for attenuation in the nuclear image includes a tool for the formation card attenuation correction (AC) from the image of MR entity, means for the transmission of radiation through the object, and a means for the transmission of radiation located outside of the subject, and a means for measuring data bandwidth radiation passed through the subject. The device additionally contains a tool for the formation of the evaluated data bandwidth from the map AC and means for the formation of the elaborated card AC via the settings of the card AC on the basis of comparison of measured data transmission and evaluated data bandwidth.

One of the advantages is that improves the accuracy of the map attenuation correction.

Another advantage is the resolution of uncertainty between the bone and air elements dimensional image in a knowledge-based MR map attenuation correction.

Moreover, the additional advantages of the present invention will be obvious to specialists in the field of technology by reading the following detailed description.

Invention can be implemented in the form of various components and combinations of components, and various phases and combinations stages. The drawings are intended only to illustrate different aspects and should not be construed as limiting the invention.

Figure 1 illustrates a system that promotes the use of a point or line source(s) for a precise setting of the card attenuation MR according to different aspects described in the materials of this application.

Figure 2 illustrates the location of the point source in the device for building nuclear images in accordance with one or more aspects described in the materials of this application.

Fig.3 graphic illustrates the dependence between the measured data bandwidth point-source and multi-column histogram, which fall into the respective data.

Fig.3 graphic illustrates the dependence between modelled or measured data bandwidth point source generated by the processor using the algorithm(s), ray tracing, and many columns, histograms, which fall into the corresponding simulated data.

Fig.3 graphic illustrates the dependence of the difference between the values of the measured data bandwidth point source and values data transmission and multi-column histogram, which fall into the respective data to the difference.

Figure 4 illustrates the method of formation of the elaborated card AC to amend the attenuation in the nuclear image in accordance with the various aspects described in the materials of this application.

Figure 5 illustrates the approximate system of in-patient medical institution, which can include a multitude of imaging devices, such as device MR imaging and nuclear scanner, which form the image data, which are redesigned individual or shared processors reconstruction for forming of three-dimensional representations of the images.

When MR image is segmented into different types of tissue, can be evaluated each tissue type and the appropriate property of the attenuation of radiation. Of MR image and the estimated values of bandwidth for each segment, you can calculate the estimated transmission on any beam through the object. Calculated the estimated transmission for each beam actually collected data bandwidth of a point source. Through a comparison of the estimated and actually measured bandwidth over the corresponding rays may be identified deviations in the values are evaluated bandwidth. It should be noted that many of the rays pass through different segmented region, as well as through General segmented region, but with different length of trajectories in each area. The area, estimated as being in the air or bone, can easily be verified. Moreover, the value of attenuation/bandwidth for each segmented region can be iterative tuning the attenuation coefficients until will not be optimized correspondence between the estimated and actually received by passing on the rays from a point source.

Similarly, the inability to optimize the data that may not be within the pre-selected threshold, may indicate a patient movement. Iterative set the position of a body contour and inland areas as a single whole, or to the provisions of the internal areas within the contour of the body can be made to optimize the matching and/or detect the movement of the patient.

It should be noted that the device 12 MR imaging device and 20 for building nuclear images or scans can be individual devices imaging or may be a combination of the device or imaging double action, in accordance with the different variants of implementation. For example, the case imager double action, the subject is scanned using the method of MR imaging, and then re-scanned using the method of building nuclear images (for example, PET or SPECT) after point source was located in the imaging device. In this way, the movement of the subject can be minimized between scans. Additionally, in this and other variants of implementation, the location of the point source can be maintained constant and/or can be determined, so that it is agreed between scans for building nuclear images, in order to facilitate the detection of data bandwidth from them.

System 10 includes the memory 34, which stores data 14 images MR map 16 AC, measured data 22 point source, simulated or estimated data 24 bandwidth of a point source and a revised map 32 AC. Memory also stores the algorithm(s) 26 ray tracing is used to create, data 24 bandwidth program 28 comparison (for example, machine-executable compare data with measured data point source) and the algorithm(s) 30 iterative exact settings used to Refine the card 16 AC during the formation of the elaborated card 32 AC.

Additionally, the system 10 includes processor 36, which analyses the data, stored in memory, 34, and performs algorithms stored in memory for generating new data to be stored in memory 34. For example, the processor executes one or more algorithms 38 reconstruction MR for the reconstruction of the image 14 MR from raw data 40 MR collected during scanning MR subject. Similarly, the processor executes one or more algorithms 39 reconstruction nuclear image for reconstruction nuclear image 23 projection of raw data 41 nuclear scan, collected during a nuclear scan of the subject. Additionally, the processor executes algorithms ray tracing for the formation of the evaluated data 24 bandwidth, resulting in the execution of the program 28 comparison to determine the difference between assessed data 24 and measured data 22 bandwidth of a point source, and performs the algorithm(s) 30 iterative accurate settings for the formation of the elaborated card 32 AC from the original card 16 AC. It should be noted that «algorithm», as used in the materials of this application, can be interpreted to indicate one or more of machine-executable commands stored permanently in memory 34 and executed by the processor 36.

Thus, the system 10 applies to the premises of the point source (or line source) in the field of research of the formation of nuclear images with the subject. In one example, a point or line source of radiation is labelled with energy, other than isotope PET used to generate the image PET subject, in order to facilitate the distinction between isotope imaging and a point or a line source. Radiation of a point or line source is detected detectors PET, separately from the data PET algorithms 42 differentiation of energy (for example, stored in memory 34 and executed by the processor 36), and is used to generate the data of radiation bandwidth, more accurately, projection through the subject. Through the use of two or more sources of radiation, or by turning the source of radiation regarding a patient, easily formed a three-dimensional map of the attenuation of radiation. A point or a line source can be temporarily inserted in the portal or device 20 for building nuclear images or bearing design of the patient, or can be permanently mounted. For example, the selection, the design can be defined in a pre-selected known location on the support of the patient or design which determines the diameter of the light. Known source location facilitates the analysis of the project data. Alternatively, the source location can be determined through the analysis of data projection.

According to yet another variant of implementation, map attenuation is deduced from the way of establishing the anatomical image, such as a scanner 12 MR. Many point sources 18, in particular, can be applied to obtain the best performance. In the following example, however, described the combination of PET/MR single point source. According example, MR image of the object or the patient is formed using the scanner 12 MR. Sets the shape of the body and other borders of the internal organs. The area, known on the merits or completely are soft cloth, are identified and marked. scope(s), such as the lung tissue, which includes air, and bone remains untagged.

Creates a nuclear image (such as a PET or SPECT) of the same object or the patient (e.g., going nuclear data image). Simultaneously, another power window for receiving impulses from the radioactive point source 18, appropriately located outside the borders of the patient or object, but within the field of research in the portal Builder of nuclear images. For example, the standard energy dialog is used for imaging SPECT, and energy window and cherepichniy» mode is used for PET imaging. Point source has a higher energy than the emission data generated by the radioactive isotope used to form images of the patient or the object (for example, 137 Cs 662 at formation of image data PET at 511 ). Path or an outline of the body is additionally promotes differences radiation of a point source of scattering. Additionally, the use of a point source with an energy higher than the radiation PET facilitates differences radiation of a point source of radiation scattering PET, because the radiation from a point source does not overlap with the scattering of radiation PET more low energy. Data from the source(s) are collected and accumulated in a histogram, or projection, which is stored in memory 34. Attenuation coefficients are assigned (for example, the processor when the formation of the card 16 AC) popular areas of segmented image of MR. The mathematical model is built using the ray tracing algorithm for the formation of the evaluated data 24 projection based on MR card 16 attenuation with the same geometry as the external point source (see figure 2). Unknown areas assigned the values of air or bone, alternatively, until the estimated or simulated mathematical data 24 projection through the card 16 attenuation not correspond to the close measured data, 22 bandwidth of a point source. Refined card 32 AC, properly segmented and properly assigned values for various uncertain areas of air or bone, can be used to perform attenuation correction nuclear image 23. Once the air or bony areas, at the choice of optimized attenuation coefficients for the different areas of soft tissues.

In another embodiment, two or more of point source 18, 18', with different energy energies bandwidth posted around the area of research to create a full field of vision. In this way, two or more linear integrals are formed to promote the resolution of uncertainty between the bone and air elements dimensional image in the image data MR.

In another embodiment, nuclear detectors are 70 detectors PET, and attenuation of the data collected PET is adjusted using the described in the materials of this application of the elaborated card AC during the reconstruction of the image of the PET.

In another embodiment, nuclear detectors 70 are single single photon detectors positron computed tomography (SPECT), and attenuation of the data collected SPECT is adjusted using the described in the materials of this application of the elaborated card AC during the reconstruction of the image SPECT.

Fig.3 graphic illustrates the dependence of 71 between the measured data 22 bandwidth point-source and multi-column histogram, which fall into the respective data. The measured data 22 bandwidth point source are measured in connection with evaluated data 24 bandwidth point source (fig.3)to iteratively Refine map AC until it is ready to be used for attenuation correction PET.

Fig.3 graphic illustrates the dependence of 72 between modelled or measured data 24 bandwidth point source generated by the processor using the algorithm(s) 26 (1) of ray tracing, and many columns, histograms, which fall into the corresponding simulated data. Estimated data 24 bandwidth point source are compared with the measured data 22 point source, and shall determine whether the card AC for use in making amendments to the attenuation in the PET scan data during the reconstruction of the image of the PET.

Fig.3 graphic illustrates the dependence of 71 difference between the values of the measured data bandwidth point source and values data transmission and multi-column histogram, which fall into the respective data to the difference. The difference is determined when the processor 36 enforces the program 28 comparison of figure 1. With each iteration setting in relation card AC, the difference is reduced. As soon as the value of the difference between assessed and measured data bandwidth is small enough (for example, below a predefined threshold), the improved map AC is stored for use when attenuation correction PET.

Figure 4 illustrates the method of formation of the elaborated card AC to amend the attenuation in the nuclear image in accordance with the various aspects described in the materials of this application. 78 MR image formation of the subject. 80 card AC is formed from the segmented image MR subject. 82 the subject is placed in the field of nuclear research of the scanner (for example, PET or SPECT) with a point source located outside the territory and within the study area. Point source emits gamma rays with energy higher than that of a radioactive isotope (for example, 511 Kev)entered in the subject, such as Cs-137 (for example, approximately 662 ). As an alternative, lower energy (for example, lower than 511 Kev) is used for point source, such as 133 Ba (for example, approximately 360 Kev).

84 data bandwidth from a point source are measured using nuclear scanner and formed nuclear image data subject. For example, PET scanner running in mode can measure the bandwidth of a point source at the same moment as the data emission of nuclear isotope, such as shown in Fig. 3A. 86 data bandwidth output or are estimated using technology ray tracing on the map AC, such as shown on fig.3.

88 determined by the difference between the data bandwidth from 84 and data projection of 86, as shown in fig.3.

90 calculated coefficient of variation, representing the difference, some 88, such as root-mean-square (rms) deviation, or the like.

As shown in figure 5, the approximate system 100 in-patient medical institution can include a multitude of imaging devices, such as device 12 MR imaging, nuclear scanner 20 (for example, PET or SPECT), or the like, which form the image data, which are redesigned individual or shared processors 102 reconstruction for forming of three-dimensional representations of the images. View the images are transmitted through a network of 104 in Central memory 106 or local memory 108.

At the station 110, the network is connected, the operator uses the user interface 124 to move the selected three-dimensional map of attenuation MR patient, or between Central memory 106 and local memory 108. Videoprocessor 116 displays the selected map attenuation (or image MR) in the first window 118 1 viewing device 122 display. Nuclear image is displayed in the second window 118 2 viewing. Third window 118 3 viewer can display overlay maps decay and nuclear image. For example, a user can be given the opportunity to combine landmarks in the map attenuation MR corresponding structures or benchmarks in nuclear image. For example, the operator's interface 124, selects the guidelines of the nuclear image (for example, using a mouse, pen, or other suitable user input device)that comply with the benchmarks in the map image of attenuation. Alternatively, the map attenuation can be aligned automatically program the processor 116. Processor 36 (1) in the user interface 124 then executes algorithms correction and makes a conclusion about the appropriate type of tissue (for example, bone or air) for use when completing the controversial areas in the map attenuation.

Refined attenuation map can then be used for reconstruction of the adjusted attenuation nuclear images that can be used in other applications. For example, the station 130 treatment planning can use the adjusted fading image of the PET for planning the treatment. As soon as satisfying the operator therapy is scheduled, it in those cases when such therapy corresponds to the automatic procedure can be therapeutic device 132, which implements the planned session. Other stations can use the adjusted fading image of the PET in various other planning processes.

In another embodiment, the imposition displayed in the window 118 3 view is customizable for weighing image on nuclear MR image, or Vice versa. For example, a ruler or a slider button (not shown), which can be mechanical or submitted on the device 122 display and be manipulated input device can be configured to change the weight of MR image or nuclear image. In one example, the operator can configure the image in the window 118 3 view from the image data pure MR (shown in the 118 1 viewing), through numerous and continuous combination of image data and MR nuclear images to pure nuclear data image (displayed in the window 118 2 viewing). For example, the ratio of image data to MR nuclear data image can discretely or continuously adjusted from 0:1 to 1:0. As another one of the choices, MR image can be displayed in the scale of levels of gray and nuclear image can be coloured. Anatomical landmarks in the MR image of help correlate the nuclear image with the subject.

The invention was described with reference to several options for implementation. After reading and understanding the specialist will be obvious to modify and change the preceding detailed description. It is assumed that the invention be construed as including all such modifications or changes as far as they fall within the scope of an accompanying the claim of the invention or its equivalents.

1. The system (10) correction anatomical image, which includes: shaper (12) images magnetic resonance (MR), which receives data (14) MR image of the subject (60) while scanning for data collection MR; nuclear scanner (20), which receives nuclear data (23) image of the subject (60) during the scan for nuclear data collection, and simultaneously measure data (22) transmission from the source (18) radiation, located in the area of research nuclear scanner (20); and a processor that builds the map (16) attenuation correction (AC) of the data (14) MR image; iteratively clarifies the map (16) AC to form an updated map (32) AC with the use of measured data bandwidth (22); and adjusts the nuclear data (23) the image with the attenuation using the elaborated card (32) AC.

2. The system of claim 1 in which the processor (36) performs: algorithm (26) ray tracing with regard card (16) AC for the formation of the evaluated data bandwidth (24); comparison of (28), which defines the difference between assessed data (24) bandwidth and measured data (22) transmission; and setting values of attenuation in the map AC to reduce the difference between assessed and measured data bandwidth.

4. The system of claim 2, in which the processor (36) maintains an updated map (32) AC in memory (34), if it is determined that the difference is minimal.

5. The system of claim 1, in which a nuclear scanner (20) is the scanner positron emission tomography (PET), which retrieves the data from the radiation emitted from a radioactive isotope, entered in the subject (60) and that has an energy level of about 511 Kev, and thus a source of (18) radiation is the radioactive material with an energy level that is different from approximately 511 Kev.

6. The system of claim 1 in which the source (18) radiation, installed in the fixed place on or in at least one of the following: support (62) the patient, which is the subject (60), in the field of research portal (64) nuclear scanner (20); and the portal (64).

7. Way to Refine card attenuation correction (AC) magnetic resonance (MR), which consists in the fact that: they form a map (16) attenuation correction (AC) of the data (14) MR image of the subject (60); miss radiation from the source (18) radiation through the subject (60), the radiation source is located outside entity; measure data (22) bandwidth based on the emission, which is run through the subject; form the estimated data (24) bandwidth of the card (16) AC; and form a revised map (32) AC via the settings of the card (16) AC on the basis of comparison of measured data (22) bandwidth and evaluated data (24) bandwidth.

8. The method according to claim 7, advanced, which consists in the fact that the form data positron emission tomography (PET); adjust the data PET using the elaborated card AC; and remodel the corrected data PET in PET image.

9. The method according to claim 7, advanced consists in the fact that: first determine the discrepancy between the measured data bandwidth and estimated data bandwidth; configure the card (16) AC to reduce discrepancies; determine the second evaluated data bandwidth using a customized card AC; define the second discrepancy between the measured data transmission and second-valued data bandwidth; and additionally configure the card (16) AC to further reduce the differences.

10. The method of claim 9, wherein determining the difference is that: the iterative determine the root-mean-square (rms) values, and configure the card (16) AC until some RMS are not optimized.

11. Machine-readable carrier (34), having recorded on a software to manage one or more computers to perform the way to 10.

12. The method according to claim 7, in which the scanner PET receives data from the radiation emitted from a radioactive isotope, entered in the subject (60) and that has an energy level of about 511 Kev) and source (18) radiation is the radioactive material with an energy level that is different from approximately 511 Kev.

13. Scanner positron emission tomography (PET), which includes: ring of detectors (70) radiation; source (18) radiation, permanently installed within ring radiation detectors; processor (36), programmed to complete method according to claim 7, in order to form an updated map (32) attenuation correction (AC). algorithm (39) reconstruction, which corrects the data PET of the detectors (70) radiation with the help of an updated map (32) AC and reconstructs the corrected data PET subjected attenuation correction image of the PET.

14. Scanner single photon emission computed tomography (SPECT), including: the set of detectors (70) radiation; source (18) radiation, permanently installed within the field of research of radiation detectors; processor (36), programmed to complete method according to claim 7, in order to form an updated map (32) attenuation correction (AC). algorithm (39) reconstruction, which corrects the data SPECT of the detectors (70) radiation with the help of an updated map (32) AC and reconstructs the corrected data PET subjected attenuation correction SPECT image.

15. Way to Refine card (16) attenuation correction (AC), which consists in the fact that: they form a map (16) AC of the data collected (14) magnetic resonance imaging (MR); and distinguish between the bone and air elements volumetric image of the data (14) MR image using data bandwidth, detected from the radioactive point source (18); and update the map (16) AC on the basis of the detected data bandwidth of a point source.