JP4609298B2 - Diagnostic imaging support device - Google Patents

Description

  The present invention relates to an image diagnosis support apparatus that performs diagnosis support using a medical image, and is obtained in particular according to three-dimensional distribution data of a radiopharmaceutical corresponding to a three-dimensional distribution in a subject of a radiopharmaceutical administered to the subject. The present invention relates to a technique for finding a radiopharmaceutical accumulation in a radiopharmaceutical distribution image.

Conventionally, as a device for supporting image diagnosis, computer diagnosis support (Computer-Aided)
Diagnosis (CAD) system. Conventional CAD image diagnosis support apparatuses target X-ray images (for example, mammogram, CT, etc.) or MRI images (for example, see Patent Documents 1 to 3).

JP-A-8-294479 (pages 12-17, FIGS. 1-21) JP 2004-135868 A (pages 17 to 21, FIGS. 1 to 18) JP 2004-173910 A (pages 5 to 8, FIGS. 2 and 5)

However, γ-rays generated from a subject administered with a radiopharmaceutical labeled with a positron-emitting radioisotope (RI = radioisotope) such as ¹¹ C, ¹³ N, ¹⁵ O, and ¹⁸ F are detected and detected. In the case of an ECT (Emission Computer Tomograpy) apparatus such as a PET apparatus that obtains three-dimensional distribution data of a radiopharmaceutical corresponding to the three-dimensional distribution of the radiopharmaceutical in a specimen, a radiopharmaceutical distribution image (according to the three-dimensional distribution data) There is no CAD system image diagnosis support device for (RI distribution image).

Furthermore, to explain using a PET apparatus as an example, there is naturally no CAD-based image diagnosis support apparatus that identifies the presence or absence of abnormal accumulation of radiopharmaceuticals in RI distribution images acquired according to the three-dimensional distribution data of radiopharmaceuticals.
In other words, there is no image diagnosis support in the field of nuclear medicine diagnosis.

  In general, when detecting a lesion from a medical image, if threshold processing is simply performed, sensitivity and specificity tend to be in a pair relationship. If the difference between the pixel value of the target location and the pixel value of the other location is taken and falls below a preset pixel value threshold, the pixel value of the target location is the pixel value of the lesion location In the following, an example will be described in which the pixel value of the target is detected as a pixel value of a lesioned part when the pixel value is detected as a normal part and exceeds a preset pixel value threshold value.

  When detection is performed with a lower pixel value threshold, the number of detected initial lesion candidates increases and the sensitivity increases, but false positives (which are judged to be abnormal although normal) are increased among the initial candidates. , The specificity goes down. On the other hand, when the pixel value threshold is increased and detected, the possibility that the detected initial candidate for the lesion is a lesion increases and the specificity increases, but false negatives (other than the initial candidate are normal but normal) The sensitivity decreases.

Here, the sensitivity is a rate (%) at which a test value performed on a population having a specific disease is positive (abnormal), and the sensitivity is represented by a / (a + b). The specificity is a rate (%) at which a test value performed on a population having no specific disease is negative (normal), and the specificity is expressed by d / (c + d). “a” to “d” are sampling numbers of a group as shown below.
a: Number of samplings showing positive in a population having a specific disease b: Number of samplings showing negative in a population having a specific disease c: Number of samplings showing positive in a population having no specific disease d: Specific Sampling numbers that were negative in a population with no disease

  In the RI distribution image acquired according to the three-dimensional distribution data of the radiopharmaceutical, there is always a physiological normal accumulation in addition to the abnormal accumulation of the radiopharmaceutical. Therefore, from the viewpoint of quickly finding out only abnormal accumulation of radiopharmaceuticals and performing image diagnosis support, it is important to consider how much normal physiological accumulation can be removed in consideration of the above-mentioned pixel value thresholds, etc. It becomes.

  The present invention has been made in view of such circumstances, and an object thereof is to provide an image diagnosis support apparatus capable of accurately performing image diagnosis support even in the field of nuclear medicine diagnosis.

In order to achieve such an object, the present invention has the following configuration.
That is, the image diagnosis support according to the invention of claim 1 is different in projection direction in accordance with (A) the three-dimensional distribution data of the radiopharmaceutical corresponding to the three-dimensional distribution of the radiopharmaceutical administered to the subject. MIP image acquisition means for acquiring MIP images that are a plurality of maximum value projection images; (B) Drug accumulation detection means for detecting accumulation of radiopharmaceuticals in the plurality of maximum value projection images acquired by the MIP image acquisition means; (C) Accumulation state determination means for determining whether the radiopharmaceutical accumulation detected by the drug accumulation detection means in the plurality of MIP images is normal accumulation or abnormal accumulation; and (D) abnormality by the accumulation state determination means. It is characterized by comprising image display means for displaying a maximum value projection image in which accumulation of radiopharmaceuticals determined to be accumulated is present.

  [Operation / Effect] When image diagnosis support is performed by the image diagnosis support apparatus according to the first aspect of the present invention, according to the three-dimensional distribution data of the radiopharmaceutical corresponding to the three-dimensional distribution of the radiopharmaceutical administered to the subject. A plurality of MIP (Maximum Intensity Projection) images having different projection directions are acquired as a radiopharmaceutical distribution image by the MIP image acquisition means, and the accumulation of radiopharmaceuticals in the MIP image acquired by the MIP image acquisition means is acquired by the drug accumulation detection means. Detected. Further, the accumulation state determining means determines whether the accumulation of the medicine detected by the medicine accumulation detecting means is normal accumulation or abnormal accumulation. Then, the MIP image with the accumulation of the radiopharmaceutical determined to be abnormal accumulation by the accumulation state determination means is displayed by the image display means and is used for observation by the image interpretation doctor.

  The MIP image acquired according to the three-dimensional distribution data of the radiopharmaceutical in the image diagnosis support apparatus according to the invention of claim 1 is obtained by projecting the three-dimensional distribution data of the radiopharmaceutical in an arbitrary viewpoint direction and data in each projection path. Is the image in which the largest data (maximum value) appears on the projection plane, and the MIP image has a sufficient three-dimensional distribution of the radiopharmaceutical compared to the tomographic image showing only the two-dimensional distribution of the radiopharmaceutical. In addition, the three-dimensional distribution state of the radiopharmaceutical is widely reflected in a plurality of MIP images having different projection directions. That is, a plurality of MIP images with different projection directions correspond well with the accumulation state of the radiopharmaceutical, and as a result, the accumulation of the radiopharmaceutical in the MIP image can be reliably detected.

In the case of the diagnostic imaging support apparatus according to the first aspect of the invention, a plurality of MIP images with different projection directions that correspond well with the radiopharmaceutical accumulation state are acquired as radiopharmaceutical distribution images, and the radiopharmaceutical accumulation in the MIP image is ensured. In addition to detecting, it is determined whether the radiopharmaceutical accumulation is normal accumulation or abnormal accumulation, and then the MIP image with the accumulation of radiopharmaceutical determined to be abnormal accumulation is displayed. Diagnosis is very easy.
Therefore, according to the diagnostic imaging support apparatus of the first aspect of the present invention, diagnostic imaging support can be performed accurately even in the field of nuclear medicine diagnosis.

  The invention according to claim 2 is the image diagnosis support apparatus according to claim 1, wherein (E) a part extracting means for extracting the MIP image for each part of the subject, and (F) for each part of the subject. And a criterion storage means for preliminarily storing the characterized criterion, and the accumulation state determination means determines the normal accumulation and the abnormal accumulation of the radiopharmaceutical accumulation detected by the medicine accumulation detection means. This is performed based on the extraction results of the parts and the determination criteria characterized for each part of the subject.

  [Operation / Effect] In the case of the diagnostic imaging support apparatus of the invention of claim 2, normal accumulation and abnormal accumulation determination regarding the accumulation of radiopharmaceuticals is performed according to the determination criteria characterized for each part of the subject. Thus, the determination of normal accumulation and abnormal accumulation of radiopharmaceutical accumulation is accurately performed.

  The invention according to claim 3 is the diagnostic imaging support apparatus according to claim 1 or 2, further comprising (G) tomographic image acquisition means for acquiring a tomographic image according to the three-dimensional distribution data of the radiopharmaceutical. The image display means displays the tomographic image acquired by the tomographic image acquisition means side by side with the maximum value projection image.

  [Operation / Effect] In the case of the image diagnosis support apparatus according to the third aspect of the present invention, different types of radiopharmaceutical distribution images of the maximum value projection image and the tomographic image are displayed side by side. .

  The invention of claim 4 is that the three-dimensional distribution data of the radiopharmaceutical is obtained by a PET (Positron Emission Tomograpy) apparatus.

  [Operation / Effect] In the case of the diagnostic imaging support apparatus according to the fourth aspect of the present invention, diagnostic imaging support can be performed when diagnosis is performed using the three-dimensional distribution data of the radiopharmaceutical obtained by the PET apparatus.

In the case of the image diagnosis support apparatus of the present invention, a plurality of MIP images with different projection directions that correspond well with the radiopharmaceutical accumulation state are acquired as radiopharmaceutical distribution images, and the radiopharmaceutical accumulation in the MIP image is reliably detected. In addition, since it is determined whether the accumulation of radiopharmaceuticals is normal accumulation or abnormal accumulation, MIP images with accumulation of radiopharmaceuticals determined to be abnormal accumulation are displayed. It becomes easy.
Therefore, according to the image diagnosis support apparatus of the present invention, image diagnosis support can be performed accurately also in the field of nuclear medicine diagnosis.

  An embodiment of an image diagnosis support apparatus according to the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a PET apparatus, and FIG. 2 shows a configuration of a computer-diagnosis support (Computer-Aided Diagnosis: CAD) type image diagnosis support apparatus (hereinafter abbreviated as “CAD apparatus” as appropriate). It is a block diagram. Hereinafter, the CAD apparatus according to the embodiment will be described on the assumption that image diagnosis support is performed using the three-dimensional distribution data of the radiopharmaceutical acquired by the PET apparatus of FIG.

  The PET apparatus in FIG. 1 includes a top plate 1 on which a subject M is placed. The top plate 1 is configured to move up and down and to translate along the body axis Z of the subject M. By configuring in this way, the subject M placed on the top 1 is scanned from the head to the abdomen and foot sequentially through the opening 2a of the gantry 2 to be described later for diagnosis support. Obtain three-dimensional distribution data of the radiopharmaceutical used.

  In addition to the top plate 1, the PET apparatus of FIG. 1 has a gantry 2 having an opening 2a, a plurality of scintillator blocks 3a and a plurality of photomultipliers 3b arranged in close proximity to each other. A container 3 is provided. The scintillator block 3 a and the plurality of photomultipliers 3 b are arranged in a ring shape so as to surround the body axis Z of the subject M, and the γ-ray detector 3 is embedded in the gantry 2. The photomultiplier 3b is disposed outside the scintillator block 3a. As a specific arrangement of the scintillator block 3a, for example, two scintillator blocks 3a are arranged in a direction parallel to the body axis Z of the subject M, and many scintillator blocks 3a are arranged around the body axis Z of the subject M. Lined up forms are listed.

In addition, the PET apparatus of FIG. 1 includes a top plate driving unit 4, a PET controller 5, a memory unit 6, an input unit 7, a PET output unit 8, a projection data deriving unit 9, and a reconstruction unit 10. Yes. The top plate drive unit 4 is a mechanism that drives the top plate 1 to move as described above, and includes an electric motor (not shown).
The PET controller 5 comprehensively controls each part constituting the PET apparatus of FIG. The PET controller 5 and the CAD controller 20 of the CAD apparatus in FIG. 2 to be described later are composed of a central processing unit (CPU) and the like.

  The image memory unit 23 and the determination reference memory unit 26 of the CAD device in FIG. 2 and the memory unit 6 are configured by storage media represented by ROM (Read-only Memory), RAM (Random-Access Memory), and the like. Yes. Data processed by the projection data deriving unit 9 and the reconstruction unit 10 is written and stored in the RAM, and is read from the RAM as necessary. Various programs and the like necessary for image diagnosis support are stored in advance in the ROM, and the programs are executed by the PET controller 5 and the CAD controller 20.

  The input unit 7 of the PET apparatus in FIG. 1 and the input unit 29 of the CAD apparatus in FIG. 2 send data and commands input by the operator to the PET controller 5. The input unit 7 and the input unit 29 are configured by a pointing device represented by a mouse, a keyboard, a joystick, a trackball, a touch panel, or the like. The PET output unit 8 and the CAD output unit 28 of the CAD apparatus in FIG. 2 to be described later are composed of a display unit represented by a monitor, a printer, and the like.

  The projection data deriving unit 9, the reconstruction unit 10, and the MIP image acquisition unit 21, the tomography image acquisition unit 22, the drug accumulation detection unit 24, the site extraction unit 25, and the accumulation state determination unit 27 of the CAD apparatus in FIG. For example, the PET controller 5 or the CAD controller 20 executes a program stored in a ROM of a storage medium represented by the memory unit 6 described above or a command input by a pointing device represented by the input unit 7 or the like. It is realized by doing.

  Image information (pixels) is detected by the γ-ray detector 3 by detecting γ-rays generated from the subject M to which a radiopharmaceutical labeled with a positron emission type radioisotope (RI) is administered and converted into an electrical signal. This is sent to the projection data deriving unit 9.

  Specifically, when a radiopharmaceutical is administered to the subject M, two γ rays are generated due to the disappearance of the positron of the positron emission type RI. The projection data deriving unit 9 checks the position of the emitted scintillator block 3a and the incident timing of the γ rays, and only sends the image information sent when the γ rays are incident on the two scintillator blocks 3a constituting the pair at the same time. Judged as appropriate data. When γ rays are incident on only one of the two scintillator blocks 3a constituting the pair, the projection data deriving unit 9 treats them as noise instead of γ rays generated by annihilation of positrons, and the image sent at that time Information is also judged as noise and rejected.

The image information sent to the projection data deriving unit 9 is sent to the reconstruction unit 10 as projection data. The reconstruction unit 10 reconstructs the projection data that has been sent in, and acquires three-dimensional distribution data of the radiopharmaceutical corresponding to the three-dimensional distribution of the radiopharmaceutical administered to the subject M in the subject. The data is sent to the memory unit 6 for storage. The CAD device performs image diagnosis support using the three-dimensional distribution data of the radiopharmaceutical thus obtained.
A radiopharmaceutical distribution image such as a tomographic image can be acquired according to the three-dimensional distribution data of the radiopharmaceutical and sent to the PET output unit 8 to display or print the radiopharmaceutical distribution image.

  Necessary data can be transmitted and received between the PET controller 5 and the CAD controller 20 so that the three-dimensional distribution data of the radiopharmaceutical obtained by the PET apparatus can be transferred to the CAD apparatus. If necessary, the data obtained by the CAD device can be transferred to the PET device.

  On the other hand, the CAD apparatus according to the embodiment integrates a CAD controller 20, a MIP image acquisition unit 21, a tomography image acquisition unit 22, an image memory unit 23, a drug accumulation detection unit 24, a site extraction unit 25, and a determination criterion memory unit 26. A state determination unit 27, a CAD output unit 28, and a CAD input unit 29 are provided. The CAD controller 20 comprehensively controls each part constituting the CAD apparatus of the embodiment.

  In the CAD apparatus according to the embodiment, the MIP image acquisition unit 21 and the tomography image acquisition unit 22 are MIPs according to the three-dimensional distribution data of the radiopharmaceutical taken from the PET apparatus of FIG. 1 via the PET controller 5 and the CAD controller 20. Images and tomographic images are acquired, written and stored in the image memory unit 23, and read from the image memory unit 23 as necessary.

  The drug accumulation detection unit 24 detects accumulation of the radiopharmaceutical in the MIP image. Specific functions of the medicine accumulation detection unit 24 will be described later with reference to FIGS. The part extraction unit 25 extracts the MIP image for each part of the subject (see, for example, FIG. 5). Specific functions of the part extracting unit 25 will be described later with reference to FIGS.

  The determination criterion memory unit 26 stores in advance a determination criterion characterized for each part of the subject. Specific criteria will be described later with reference to FIGS. The accumulation state determination unit 27 determines whether the accumulation of the radiopharmaceutical detected by the drug accumulation detection unit 24 is normal accumulation or abnormal accumulation, and the extraction result of the region of the subject M by the region extraction unit 25 and the characteristics of each region of the subject M. It judges based on the attached judgment standard. Specific functions of the integration state determination unit 27 will be described later with reference to FIGS.

  Next, a specific series of processing of image diagnosis support by the CAD device of the embodiment will be described with reference to the flowchart of FIG. 3 and the explanatory diagrams of FIGS. FIG. 3 is a flowchart showing an image diagnosis support process by the CAD apparatus of the embodiment, FIG. 4 is an explanatory diagram schematically showing a MIP image when there is accumulation of radiopharmaceutical as physiological normal accumulation, and FIG. FIG. 6 is an explanatory diagram schematically showing the extraction of each MIP image for each part of the subject M, and FIG. 6 shows an example of determination criteria when there is radiopharmaceutical accumulation as a physiological normal accumulation in the chest of the subject M It is explanatory drawing which showed typically.

(Step S1) Acquisition of MIP Image A plurality of MIP images having different projection directions according to the three-dimensional distribution data of the radiopharmaceutical corresponding to the three-dimensional distribution of the radiopharmaceutical administered to the subject M by the MIP image acquisition unit 21 To get. The MIP image acquisition unit 21 acquires a plurality of MIP images having different projection directions one after another while changing the angle in the projection direction by 5 °. For example, the MIP image acquisition unit 21 acquires 36 MIP images over a range of 180 ° while changing the angle in the projection direction by 5 °. FIG. 7 shows an example of a plurality of MIP images having different projection directions. The image memory unit 23 stores the acquired MIP image.

  The MIP image is an image obtained by projecting the three-dimensional distribution data of the radiopharmaceutical in an arbitrary viewpoint direction and causing the largest data (maximum value) among the data in each projection path to appear on the projection plane. Compared to the tomographic image showing only the two-dimensional distribution of the three-dimensional distribution, the MIP image fully incorporates the three-dimensional distribution of the radiopharmaceutical, and the three-dimensional distribution of the radiopharmaceutical for a plurality of MIP images having different projection directions. Is widely reflected. That is, a plurality of MIP images having different projection directions correspond well with the radiopharmaceutical accumulation state.

  The tomographic image acquisition unit 22 acquires a tomographic image such as a coronal image, a sagittal image, or a transverse image according to the three-dimensional distribution data of the radiopharmaceutical. The “coronal” is a plane parallel to the body axis Z of the subject M and the human body divided into front and rear, and the coronal image is a coronal cross-sectional image. “Sagittal” is a plane parallel to the body axis Z of the subject M and the human body divided into left and right, and the sagittal image is a sagittal cross-sectional image. “Transverse” is a plane perpendicular to the body axis Z of the subject M, and the transverse image is a cross-sectional image. The image memory unit 23 also stores the acquired MIP image. The type of image acquired by the tomographic image acquisition unit 22 can be designated by the CAD input unit 29.

(Step S <b> 2) Detection of Drug Accumulation The drug accumulation detection unit 24 detects the accumulation of radiopharmaceuticals in the MIP image read from the image memory unit 23. The accumulation of the radiopharmaceutical can be detected by, for example, the threshold processing described above or an iris filter as described in Patent Documents 1 to 3 described above. The MIP image P in which the accumulation of the radiopharmaceutical is detected is sent to the accumulation state determination unit 27 together with the image acquisition position information and the accumulation of the detected radiopharmaceutical. In the case of a plurality of MIP images shown in FIG. 7, as for the accumulation detection result of the radiopharmaceutical in the MIP image, if attention is paid to the chest of the subject, for example, a blackened area in FIG. 8 is detected. As described above, since a plurality of MIP images having different projection directions correspond well with the accumulation state of the radiopharmaceutical, the accumulation of the radiopharmaceutical in the MIP image can be reliably detected.

(Step S3) Part Extraction In parallel with Step 2, the part extraction unit 25 extracts a MIP image for each part. For example, as shown in FIG. 5, the part extracting unit 25 extracts the head and neck part R1, the chest part R2, the upper abdominal part R3, the lower abdominal part R4, and the part of the subject M. In order to extract each part, for example, a neck or the like is set as a region index (landmark), and extraction is performed based on the set index.
Specifically, when imaging is performed with both arms raised, both arms are above the neck, so when moving from the right area to the left area or from the left area to the right area If there are three groups of image information (pixels) intermittently, it can be considered that there is a group of pixel values for one arm, a group of pixel values for the neck, and a group of pixel values for the other arm. Thus, if there are three groups of pixel values intermittently, it can be recognized as an area above the neck, and can be recognized as the head and neck R1.

  Conversely, if there is only one group of pixel values, it can be recognized as an area below the neck and can be recognized as one of the chest R2, upper abdomen R3, and lower abdomen R4. Then, using the diaphragm or the like as an index, the region between the diaphragm and the neck can be recognized as the chest R2, or the region below the neck and separated from the neck by a predetermined distance can be recognized as the chest R2.

Similarly, the upper abdomen R3 and the lower abdomen R4 may be recognized and extracted based on the index. The position information of each part extracted in this way is sent to the accumulation state determination unit 27.
In the CAD apparatus of the embodiment, the detection of the drug accumulation in step S2 and the part extraction in step S3 are performed in parallel. However, the part extraction in step S3 may be performed after the detection of the drug accumulation in step S2. Conversely, detection of drug accumulation in step S2 may be performed after site extraction in step S3.

(Step S4) Determination of Accumulation State Accumulation of the drug detected in step S2 is not necessarily abnormal accumulation. For example, as shown in FIG. 4, there is always a physiological normal accumulation. FIG. 4 shows normal accumulation Pb1 of the head, normal accumulation Pb2 of the heart, and normal accumulation Pb3 of the bladder. Therefore, the accumulation state determination unit 27 uses the medicine accumulation detection unit 24 for each part extracted by the part extraction unit 25 based on the determination criteria characterized for each part stored in advance in the determination reference memory unit 26. Normal accumulation or abnormal accumulation is determined for the accumulation of the detected radiopharmaceutical.

  The criterion stored in advance in the criterion memory unit 26 is characterized for each part. For example, in the chest R2, as shown in FIG. 6, physiological normal accumulation of the nipple N may appear strongly, so when there is accumulation at the left and right target positions of the axis Ax of the PET image P, The possibility of normal accumulation is high. Therefore, when there is accumulation at the left and right target positions in the chest R2, the accumulation is regarded as normal accumulation. The criterion for determining that the accumulation at the left and right target positions is normal accumulation is the determination criterion characterized by the chest R2.

As shown in FIGS. 4 and 5, when there is a normal accumulation Pb1 of the head, the criterion for determining that the normal accumulation Pb1 of the head is normal accumulation is the determination criterion characterized by the head and neck R1, When there is a normal accumulation Pb2, the criterion for determining the normal accumulation Pb2 of the heart as a normal accumulation is a determination criterion characterized by the chest R2 or the upper abdomen R3, and when there is a normal accumulation Pb3 of the bladder, The criterion for determining that the normal accumulation Pb3 of the bladder is normal accumulation is the determination criterion characterized by the lower abdomen R4.
In addition, normal accumulation may appear in the muscles of the whole body about 1 hour and a half after meals. In such a case, the criteria for determining that the accumulation in the muscles is normal accumulation is determined by each part. The standard.

  Based on the position information extracted by the part extraction unit 25 in step S3, it is confirmed to which part the collection detected by the medicine accumulation detection unit 24 in step S2 belongs, and the position information of this confirmed accumulation Is compared with the position information of the part of the accumulation relating to the determination criterion characterized by the part to which the accumulation belongs, and the accumulation of the radiopharmaceutical detected by the medicine accumulation detecting unit 24 in step S2 is normal accumulation or abnormal accumulation It is determined whether it is.

(Step S5) Display MIP Image with Abnormal Accumulation The CAD controller 20 displays a CAD output unit (image for displaying the MIP image in which the accumulation of the radiopharmaceutical determined to be abnormal accumulation by the accumulation state determination unit 27 (image). Displayed on display means 28 for observation by an interpreting physician. If there are a plurality of MIP images in which accumulation of radiopharmaceuticals determined to be abnormal accumulation exists, all of those MIP images are displayed in order (or simultaneously in a lump). For example, three MIP images on the right side in FIG. 7 are displayed in order as MIP images in which accumulation of radiopharmaceuticals determined to be abnormal accumulation exists. Anomalous accumulation hidden behind a large normal accumulation is surely found.

  In the case of the CAD apparatus according to the embodiment, as shown in FIG. 9, the CAD output unit 28 displays the coronal image and the sagittal image acquired by the tomographic image acquisition unit 22 side by side with the MIP image. . In FIG. 9, the coronal image and the sagittal image are shown only by the outline for convenience.

  As described above, in the case of the CAD apparatus of the embodiment, a plurality of MIP images with different projection directions that correspond well with the radiopharmaceutical accumulation state are acquired as radiopharmaceutical distribution images, and the radiopharmaceutical accumulation in the MIP image is ensured. In addition to detecting the radiopharmaceutical, it is determined whether the accumulation of the radiopharmaceutical is normal accumulation or abnormal accumulation, and then the MIP image with the accumulation of radiopharmaceutical determined to be abnormal accumulation is displayed. Makes diagnosis very easy.

Therefore, according to the CAD apparatus of the embodiment, image diagnosis support can be performed accurately even in the field of nuclear medicine diagnosis.
In addition, since the CAD apparatus according to the embodiment displays different types of radiopharmaceutical distribution images such as MIP images and tomographic images side by side, it is easier for an interpreting doctor to diagnose. Usually, the image interpretation doctor first looks at the MIP image, and then looks at the coronal image and the sagittal image.

The present invention is not limited to the above embodiment, and can be modified as follows.
(1) In the above embodiment, the PET apparatus has been described as an example. However, the present invention can be applied to a nuclear medicine diagnostic apparatus other than a PET apparatus such as SPECT (Single Photon Emission CT). The present invention can also be applied to an apparatus combining a nuclear medicine diagnostic apparatus and an X-ray CT apparatus, such as a PET-CT equipped with a line CT apparatus.

  (2) In the above embodiment, the γ-ray detector 3 is a stationary type. However, the γ-ray detector 3 may be a rotary type that detects γ-rays while rotating around the subject M.

  (3) The above embodiment can also be applied to an apparatus provided with an external radiation source in the vicinity of the subject in order to perform absorption correction. That is, the subject M is irradiated with γ rays from an external radiation source to obtain absorption correction data (transmission data), and the reconstructing unit 10 performs radiopharmaceuticals based on the corrected data obtained by performing the absorption correction using the absorption correction data. It is also possible to acquire the three-dimensional distribution data.

  (4) In the above embodiment, the PET device that acquires the three-dimensional distribution data of the radiopharmaceutical and the CAD device that supports the image diagnosis using the three-dimensional distribution data of the radiopharmaceutical are separated from each other. Although it was the structure which transmits / receives required data between CAD apparatuses, the structure which incorporated the CAD apparatus in the PET apparatus and united both apparatuses may be sufficient. In this case, the configuration is such that the PET controller and the CAD controller are combined into one controller, and the PET input unit / output unit and the CAD input unit / output unit are combined into a single input unit / output unit. That's fine.

(5) In the above embodiment, the criterion used as a basis for determining whether the radiopharmaceutical is accumulated normally or abnormally is stored in the criterion memory unit 26 in advance. It is also possible to store the determination criteria to be stored in the determination criterion memory unit 26 in advance, and input the determination criteria to be changed according to the imaging state through the CAD input unit 29 and send it to the integrated state determination unit 27 each time.
Further, the fixed determination criteria may not be stored in advance, and all the determination criteria may be input through the CAD input unit 29.

It is a block diagram which shows the structure of the PET apparatus which acquires the three-dimensional distribution data of the radiopharmaceutical used with the CAD apparatus of an Example. It is a block diagram which shows the structure of the CAD apparatus of an Example. It is a flowchart which shows the image diagnosis assistance process by the CAD apparatus of an Example. It is explanatory drawing which shows typically a MIP image when there exists physiological normal accumulation. It is explanatory drawing which shows typically when the MIP image of FIG. 4 is extracted for every part of the subject. It is explanatory drawing which showed typically an example of the determination criteria when there is physiological normal accumulation in the chest of the subject. It is a schematic diagram which shows the specific example of the several MIP image acquired in the Example. It is explanatory drawing which shows typically the accumulation state of the radiopharmaceutical in the MIP image of FIG. It is a schematic diagram which shows a coronal image and a sagittal image corresponding to a MIP image with an abnormal accumulation of radiopharmaceuticals side by side.

Explanation of symbols

DESCRIPTION OF SYMBOLS 21 ... MIP image acquisition part 22 ... Tomography image acquisition part 24 ... Drug accumulation | storage detection part 25 ... Site extraction part 26 ... Judgment reference | standard memory part 27 ... Accumulation state determination part 28 ... Output part for CAD (image display means)
M: Subject P: MIP image (maximum value projection image)

Claims (4)

(A) MIP image acquisition that acquires MIP images that are a plurality of maximum-value projection images with different projection directions according to the three-dimensional distribution data of the radiopharmaceutical corresponding to the three-dimensional distribution of the radiopharmaceutical administered to the subject. Means, (B) drug accumulation detection means for detecting accumulation of radiopharmaceuticals in the plurality of maximum value projection images acquired by the MIP image acquisition means, and (C) drug accumulation detection in the plurality of MIP images (D) a maximum-value projection image in which there is accumulation of radiopharmaceuticals determined to be abnormal accumulation by the accumulation state determination means; And an image display means for displaying the image diagnosis support apparatus.   2. The diagnostic imaging support apparatus according to claim 1, wherein (E) a part extracting unit that extracts a MIP image for each part of the subject, and (F) a criterion that is characterized for each part of the subject is stored in advance. Determination criteria storage means, and the accumulation state determination means determines the normal accumulation and the abnormal accumulation regarding the accumulation of radiopharmaceuticals detected by the drug accumulation detection means. An image diagnosis support apparatus which is performed based on a determination criterion characterized for each part.   3. The diagnostic imaging support apparatus according to claim 1 or 2, further comprising: (G) a tomographic image acquisition unit that acquires a tomographic image according to three-dimensional distribution data of the radiopharmaceutical, wherein the image display unit acquires the tomographic image. An image diagnosis support apparatus that displays a tomographic image acquired by a means side by side with a maximum value projection image.   The diagnostic imaging support apparatus according to any one of claims 1 to 3, wherein the three-dimensional distribution data of the radiopharmaceutical is acquired by a PET (Positron Emission Tomograpy) apparatus.

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