JP5439078B2 - Magnetic resonance imaging apparatus and method of operating the same - Google Patents

Description

  The present invention relates to a magnetic resonance imaging (MRI) apparatus that measures nuclear magnetic resonance (hereinafter referred to as “NMR”) signals from protons in a subject and visualizes proton density distribution, relaxation time distribution, and the like. More specifically, the present invention relates to a magnetic resonance imaging apparatus that performs multi-slice imaging with an MRI apparatus and recommends and displays a slice image to be interpreted from the captured multi-slice image.

  Multi-slice imaging with an MRI apparatus is an imaging method in which a subject is sliced and a plurality of 2D MR images are measured over the entire subject in one imaging (sequence is executed once). Since it is possible to image whole organs and tissues with a single imaging, it is applied to the inspection of the brain and heart, as well as the inspection of cartilage.

  However, in order to make a diagnosis without missing a lesion, all of the multi-slice images obtained by multi-slice imaging must be read. This places a heavy burden on the reader. Further, in order to make it easy to find the lesion site, a T1W image that emphasizes the longitudinal relaxation T1 of protons that creates different contrasts, a T2W image that emphasizes the transverse relaxation T2, and the like are added. Furthermore, changing the inversion time TI, T1W images with different contrasts in the same slice, changing the proton spin lock time STL, T1ρW images with different contrasts in the same slice, changing the echo time TE Multiple T2W images with different contrasts in the same slice, creating T1 value images, T1ρ value images, and T2 value images (hereinafter referred to as value images), and overlaying the created images on T1W images or T2W images Diagnosis of multi-slice map images is performed.

  As described above, it is necessary for an image interpreter to interpret a large number of multi-slice images for examination of a desired organ / tissue. Furthermore, in order to interpret a thin tissue such as cartilage, a process of finding a cartilage region that is a region of interest and specifying a lesion slice by adjusting a window level or the like is required. In addition, since the map image color change (when the luminance value is colored) and the factorial change in luminance are small at the initial stage of the lesion, it is difficult to determine whether the lesion is a lesion, and the diagnosis results vary depending on the reader. It is predicted.

  In order to solve the above-mentioned problems, the present invention is able to display characteristics / trends such as a profile when a region of interest of a value image created from a multi-slice image acquired by multi-slice imaging is normal and an average / variance of divided analysis regions Use this to automatically and accurately determine slices with lesions in multi-slice images, present them to the reader as recommended slices to be characterized and interpreted, and T1W images, T2W images, and value images related to the lesion slices. An object of the present invention is to link each image type such as a map image and to easily call each image type.

  In order to solve the above problems, the present invention uses the magnetic resonance imaging apparatus to extract a region of interest of the multi-slice image, and the region of interest and the features of the region of interest previously stored in the storage unit. Thus, a process for determining the presence or absence of a lesion in each slice image is added. In addition, if necessary, extract slices with lesions or vice versa and characterize them, label each image type related to the lesion slice, and call the image reader to each image type. It adds a process that makes it easier to do.

  Specifically, the magnetic resonance imaging apparatus of the present invention is a magnetic resonance imaging apparatus that performs multi-slice imaging or 3D imaging, and includes the captured multi-slice image and the T1 value image and T1ρ value image created from the multi-slice image. Or storage means for storing a T-binary image (hereinafter referred to as a value image) and storing characteristics relating to the region of interest of the value image, setting means for setting the region of interest in the multi-slice image, and the value image Extraction means for extracting the region of interest from the image, determination means for determining the presence / absence of a lesion in the region of interest of the extracted value image based on the characteristics relating to the region of interest of the value image, and based on the result of the determination means Display means for recommending and displaying a slice to be interpreted from the multi-slice image is provided.

  Further, in the magnetic resonance imaging apparatus of the present invention, the extraction unit for extracting the region of interest includes the coordinates of the region of interest set by the setting unit in a part of the multi-slice image and the characteristics of the region of interest of the value image. Used to automatically extract the region of interest of all the slice images.

  In the magnetic resonance imaging apparatus of the present invention, the determination means for determining the presence or absence of a lesion compares whether the pixel value of the region of interest extracted from the value image is in a normal range, and sets the pixel value outside the normal range to zero. And means for determining the presence / absence of a lesion based on a pattern of a region of interest where the pixel value outside the normal range is zero.

  Further, in the magnetic resonance imaging apparatus of the present invention, the means for determining the presence or absence of a lesion detects whether there is a region where the pixel value is zero within the region of interest, and if there is a region that is zero, it is determined as a lesioned portion. It includes means to do.

  In the magnetic resonance imaging apparatus of the present invention, the means for determining the presence or absence of a lesion detects whether there is a region where the pixel value is zero within the region of interest. A means for obtaining a profile of the value, T1ρ value, or T2 value and comparing with a normal profile and determining that the two are different from each other.

  In the magnetic resonance imaging apparatus of the present invention, the region of interest may be a cartilage, brain, liver, or heart, and the lesion may be a cartilage, brain, liver, or heart lesion, respectively.

Method for operating a magnetic resonance imaging apparatus of the present invention is a method for operating a magnetic resonance imaging apparatus which performs multi-slice imaging or 3D imaging, from the storage means, a multi-slice imaging was Tsu line, or, 3D image 3D imaging was expanded to a multi-slice images, and obtaining a multi-slice image, the extraction unit, extracting a region of interest for all the slices of the multi-slice, decision means, for all regions of interest of the extracted value image, the value A step of determining the presence or absence of a lesion using normal characteristics that are not a lesion in the region of interest of the image, and a step of displaying a slice to be interpreted as a recommended slice based on the result of the determination by the display means It is.

In the method of operating the magnetic resonance imaging apparatus of the present invention, the step of extracting the region of interest selects a value image for each slice and stores it as a value image group, and selects an ROI setting image for each slice. Storing as a ROI setting image group, selecting from the ROI setting image group at least a first slice and a final slice as a reference image, a user setting a region of interest in the reference image, and a reference And estimating the region of interest of the ROI setting image excluding the reference image based on the region of interest set in the image.

Further, in the operation method of the magnetic resonance imaging apparatus of the present invention, the step of determining the presence or absence of a lesion applies the set or estimated region of interest to the value image, and the value image of the region of interest Comparing the pixel value of the extracted region of interest within the normal range, setting the pixel value outside the normal range to zero, and the pattern of the region of interest with the pixel value outside the normal range set to zero And determining the presence or absence of a lesion based on the above.

In the operation method of the magnetic resonance imaging apparatus of the present invention, the step of determining the presence or absence of a lesion detects whether there is a region where the pixel value is zero within the region of interest, and if there is a region that becomes zero, the lesion A step of determining a part.

In the operating method of the magnetic resonance imaging apparatus of the present invention, the step of determining the presence or absence of a lesion detects whether there is a region where the pixel value is zero within the region of interest, and if there is no region that becomes zero Includes a step of determining a T1 value, a T1ρ value, or a T2 value profile, comparing with a normal profile, and determining that the two are different from each other.

In the method for operating the magnetic resonance imaging apparatus of the present invention, the region of interest may be cartilage, brain, liver, or heart, and the lesion may be cartilage, brain, liver, or heart lesion, respectively.

  In the present invention, for multi-slice imaging in a magnetic resonance imaging apparatus, the region of interest of a multi-slice image is extracted using the characteristics of the region of interest, the presence or absence of a lesion in each slice image is determined, and the interpretation is performed by an interpreter. By recommending a slice to be performed, it is possible to reduce the burden such as the number of operations of the image interpreter, shorten the examination time, and improve the usability for simplifying the operation.

The figure which shows the MRI apparatus with which this invention is applied The figure which shows the outline | summary of the process of this invention The figure which shows the processing flow of step 22 of FIG. 2 of this invention The figure which shows the processing flow of step 223 of FIG. The figure which shows the processing flow of step 228 of FIG. The figure which shows the processing flow of step 2281 of FIG. The figure which shows the processing flow of step 23 of FIG. 2 of this invention The figure which shows the processing flow of 1st Embodiment of step 238 of FIG. The figure which shows the processing flow of 2nd Embodiment of step 238 of FIG. Explanatory drawing of direction of the cartilage area in the example of the present invention Explanatory drawing of 1st Embodiment in the Example of this invention Explanatory drawing of 2nd Embodiment in the Example of this invention Explanatory drawing which shows one example of the image display of this invention Explanatory drawing of the Example of this invention The figure which shows each image of this invention Explanatory drawing of 1st Embodiment in the Example of this invention

A magnetic resonance imaging apparatus according to the present invention will be described with reference to FIG. This magnetic resonance imaging apparatus is an apparatus that performs imaging using multi-slice imaging.
The magnetic resonance imaging apparatus includes a bed 112 on which a subject 101 is placed, a magnet 102 that generates a static magnetic field, a gradient magnetic field coil 103 that generates a gradient magnetic field in the space, and an RF transmission coil that generates a high-frequency magnetic field in this region 104, an RF receiving coil 105 that detects an MR signal generated by the subject 101, and a control unit 111 that controls the entire system.
The bed 112 can be retracted from the magnet 102 or inserted into the magnet 102. The bed 112 is moved by the bed driving unit 113. The bed driving unit 113 controls at least movement in the body axis direction (z direction) in accordance with a control signal given from the control unit 111.
The gradient magnetic field coil 103 is composed of gradient magnetic field coils in three directions of x, y, and z. In response to a signal from the control unit 111, a current is supplied from the gradient magnetic field power source 109 to the gradient magnetic field coil 103, and gradient magnetic fields orthogonal to each other are generated. For each gradient magnetic field, a slice selection gradient magnetic field, a phase encoding gradient magnetic field, and a readout gradient magnetic field can be set in arbitrary directions.
The RF transmission coil 104 generates a high-frequency magnetic field according to a signal from the RF transmission unit 110, and excites protons in the subject 101 with a high-frequency magnetic field having a Larmor frequency. Nuclear magnetization of the excited protons is received as an FID (free induction decay) signal or an echo signal by the RF receiving coil 105 and detected by the signal detection unit 106. The detected signal is subjected to processing such as FFT (Fast Fourier Transform) in the signal processing unit 107 and converted into an image signal. The image is displayed on the display unit 108. A signal processed by the signal processing unit 107 or the image, input data from the input unit 114, and a software program for extracting a region are stored in the storage unit 116.
The control unit 111 controls the gradient magnetic field power source 109, the RF transmission unit 110, the signal detection unit 106, the bed driving unit 113, and the display unit 108 in accordance with commands and signals from the input unit 114 and the signal processing unit 107. The control time chart is generally called a pulse sequence.

  In the present invention, after performing multi-slice imaging with the magnetic resonance imaging apparatus, a region of interest is extracted from the acquired multi-slice image, and the normal region that is not a lesion in the region of interest of all the extracted slices and the region of interest of the value image Using the characteristics of time, the presence or absence of a lesion is judged and labeled. Alternatively, the judgment result and the slice to be interpreted are characterized and reflected and displayed on the GUI of the display unit. The outline of the process will be described with reference to the flowchart of FIG.

  In the flowchart of FIG. 2, after performing multi-slice imaging (step 21) with the magnetic resonance imaging apparatus, extraction of a region of interest for all slices of the multi-slice (step 22) and interest of the value image for all extracted regions of interest The presence or absence of a lesion is determined using normal characteristics that are not lesions in the region (step 23), and based on the determination result, the slice to be interpreted is displayed as a recommended slice to the interpreter (step 24). Although the present invention is described by multi-slice imaging, FIG. 2 is also applicable to a case where a 3D image captured in 3D is developed into a multi-slice image.

  As an apparatus configuration for realizing this processing flow, a captured multi-slice image and a value image created from the multi-slice image are stored, storage means for storing characteristics relating to a region of interest of the value image, and the multi-slice image Setting means for setting the region of interest; extraction means for extracting the region of interest from the value image; and whether or not there is a lesion in the region of interest of the extracted value image based on the characteristics of the value image relating to the region of interest. Judgment means for judging and display means for displaying, as a recommendation, a slice to be interpreted from the multi-slice image based on the result of the judgment means. In the MRI apparatus of FIG. 1, the signal processing unit 107, the storage unit 116, the display unit 108, the input unit 114, and the like correspond to each other.

  The present embodiment is applied to multi-slice imaging of a cartilage of a foot, and steps 22 to 24 in FIG. 2 will be described separately by taking an example of multi-slice imaging for capturing a map image of T2 value of cartilage.

  The process of step 22 will be described with reference to FIGS. FIG. 3 illustrates the flow of the process of step 22, FIG. 4 illustrates the process of step 223 of FIG. 3, and FIG. 5 illustrates the process of step 228 of FIG.

  In FIG. 3 showing the process of step 22, the relationship between each image and image group involved in the process is shown in FIG. In order to extract a multi-slice region of interest, a plurality of T2W images having different echo times TE per slice, for example, TE1, TE2,..., TEs (hereinafter referred to as morphological images (1502 in FIG. 15)) Is stored in a multi-slice image (hereinafter referred to as an original image group (1501 in FIG. 15)) (step 221), and the number of slices sn is set (step 222), and then a T2 value image from the original image group is stored. Group (1503, sn in FIG. 15) and selection of morphological images for calculation of cartilage area (sn, ROI setting image group), for example, select TE1 image of each slice in FIG. 15 as ROI setting image group (Step 223).

  The processing in step 223 is composed of three steps as shown in FIG. Each of the slices is different from step 2231 in which T2 value images are created from morphological images having different TEs that are the same slice, and the T2 value images created for all slices are stored in the storage unit 116 as a T2 value image group. Extracting and storing one set of morphological images having the same TE value as the ROI setting image group, and selecting at least the first slice and the final slice as the reference images for setting the cartilage region from the ROI setting image group This is step 2233. Note that the processing in step 2231 may be performed before step 23. In the selection of the reference image in Step 2233, the number of reference images and the slice number may be automatically selected from the ROI setting image group according to the number of slices sn.

  After selecting the reference image in step 223, the reference image is displayed on the display unit 108 (step 224), and the user sets a cartilage region (hereinafter referred to as setROIs) as a region of interest in the reference image (step 225). The setROIs in step 225 is performed until the user instructs setting completion (step 226). After the setting of the setROIs is completed, the setROIs is stored in the storage unit 116 (step 227), the cartilage region of the ROI setting image group is extracted using the setROIs, and the outer contour is obtained (step 228).

  The process of step 228 is shown in FIG. In this step, the setROIs is used to estimate cartilage regions (hereinafter, estimated ROIs) of the ROI setting image group excluding the reference image (step 2281). Thereafter, the outer contour of setROIs and estimated ROIs (the outer contour of the cartilage morphological image, hereinafter referred to as MCOLs, for example, 1401 in FIG. 14) is calculated (step 2282), and MCOLs are stored in the storage unit 116 (step 2283).

  The estimation in step 2281 can be realized using a known example of Japanese Patent Laid-Open No. 7-2342927. However, since the known example uses linear interpolation processing of a distance image, the estimation of estimated ROIs lacks accuracy. In other words, it depends greatly on the setting of setROIs, and thus differs depending on the operator. In the present invention, as shown in FIG. 6, the position of the region of interest is estimated and the cartilage region is estimated more accurately by using the normal cartilage T2 value range (hereinafter referred to as T2 value range) stored in advance in the storage unit 116. The processing of step 2281 according to the present invention includes steps 22811 to 22816. In step 22811, center coordinates of the setROIs are obtained. In step 22812, curve fitting is performed in the slice direction using the center coordinates. The center coordinates of the setROIs are obtained as points passing through the centers of the long and short axes of the setROIs. In step 22813, a position that intersects the curve obtained by the curve fitting and the slice image of the ROI setting image group excluding the reference image is determined as the position Ps of the cartilage region of the corresponding slice, and the central coordinates and Ps are stored in the memory This is stored in the unit 116. Thereafter, in step 22814, the T2 value range is called from the storage unit 116, and in step 22815, the T2 value range is subjected to threshold processing for the T2 value range, and the component outside the T2 value range is set to 0, and then the storage unit Store in 116. This is TempT2Is. In step 22816, in TempT2Is, the block of the T2 value image where the position Ps including the central coordinates is located is set as a cartilage region and stored as estimated ROIs. After the processing in step 228, the MCOLs that are the outlines of the cartilage region of the original image group can be acquired. Step 23 of FIG. 2 is entered using MCOLs.

  The process of step 23 will be described with reference to the flowcharts of FIGS. FIG. 8 shows a first embodiment of this step, and FIG. 9 shows a second embodiment of this step. FIG. 7 shows a flow common to the first and second embodiments.

  First, FIG. 7, which is a flow common to the first and second embodiments, will be described. The MCOLs are applied to the T2 value image group, and T2 value images (hereinafter referred to as CarT2Images) in the region surrounded by the MCOLs are extracted and stored (step 231), and then the T2 value range is called from the storage unit 116 (step 231). 232), the brightness value (pixel value) of CarT2Images is compared with the T2 value range, and the pixel value outside the T2 value range is set to zero and stored as ThreCT2Is (step 233).

  Regarding the ThreCT2Is, the T2 value of normal cartilage is non-patent literature Mosher TJ, Dardzinski BJ, Smith MB, Human articular cartilage: influence of aging and early symptomatic degeneration on the spatial variation of T2--preliminary findings at 3 T, Radiology, Since it is within a certain range from 259-266 (2000), it becomes four patterns from 1402 to 1405 shown in FIG. The patterns 1402 and 1404 are patterns having no zero area inside ThreCT2Is, and the patterns 1403 and 1405 are patterns having a zero area.

  After the processing in step 233, the slice counter sc is set to 0 (step 234), and it is detected whether or not there is a region that becomes zero in the ThreCT2Is (step 235). Based on the detection result, it becomes zero. When it is determined that there is a region (step 236), the corresponding slice is determined to be a lesion slice, each image type such as a related morphological image and T2 value image is labeled and stored (step 237), and then the slice counter 1 is incremented (step 239), and it is determined whether the slice counter has reached the number of slices sn (step 2310). If sc is sn, the determination of whether or not there is a lesion has been completed for all slices, so the processing in step 23 is completed. If the sc is not sn, the process returns to the step 235 and is repeated until all slices are completed. On the other hand, if it is determined in the step 236 that a region that becomes zero is not detected in the ThreCT2Is, the processing in the step 238 for determining whether the slice does not include the zero region in the ThreCT2Is is the step described above. Proceed to 239.

  A first embodiment of step 238 will be described using the flow of FIG. If it is determined in step 236 that there is no zero region inside the ThreCT2Is, the outer contour of the ThreCT2Is (hereinafter, ThreCT2IOLs, 1406 or 1407 in FIG. 14) is calculated and stored in the storage unit 116 ( Step 2380) Using the ThreCT2IOLs, the direction from the lower bone side (1601 in FIG. 16) to the cartilage fluid (1602 in FIG. 16) is determined (Step 2381).

  The processing of step 2381 is a characteristic that the profile perpendicular to the subchondral bone side of normal cartilage from the non-patent literature (hereinafter referred to as a vertical profile) has a smaller T2 value on the subchondral bone side than the T2 value on the cartilage fluid side. Is used, the direction of the cartilage region (from the lower bone side to the cartilage fluid side) can be easily obtained. FIG. 10 illustrates an example for obtaining the direction of the cartilage region. With respect to the ThreCT2IOLs, the long and short axes are separated, the boundary line 1003 passing through both ends of the long axis is taken as the heel, and the upper (1001) and lower (1002) T2 value averages are obtained and compared. The lower bone side. If there is little change in the average of the upper and lower T2 values, the lower bone side and the cartilage fluid side can be distinguished by the same method as described above in the minor axis direction.

  After the processing of the step 2381, the total number allpn of the subchondral bone side points (pixels on the ThreCT2IOLs) is obtained (step 2382). PF) is obtained (step 2384), the allpn is reduced by 1 (step 2385), and compared with the characteristics of the vertical profile of normal cartilage called from the storage unit 116 (hereinafter referred to as T2 curve characteristic), It is determined whether the PF curve characteristic tendency is the same as the T2 curve characteristic (step 2386).

  The PF in step 2384 is obtained by acquiring data on a line perpendicular to the tangent line of ThreCT2IOLs on the subchondral bone side, and normalizing with 0 on the subchondral bone side and 1 on the cartilage fluid side.

  In the processing of step 2386, as described in p261 of the non-patent document, the T2 value curve characteristic has a characteristic that the T2 value of cartilage increases from the subchondral bone side toward the cartilage fluid side. On the other hand, in the case where the zero region is not included in the ThreCT2Is but there is a lesion, the PF can be narrowed down to the patterns 1103 and 1104 in FIG. As an example, if there is a loss / lesion of the cartilage margin, the image of the same PF (1101) and T2 curve characteristics (1102) of 1104 is shown in Fig. 11 (B). If there is a lesion, the image of 1103 is shown in (C). When the cartilage side of PF (1101) in (B) is smaller than normal and the loss / lesion is on the subchondral bone side, it can be judged as a lesion by becoming larger. In (C), 1105 undulates compared with PF (1105) and 1102 above, so it is possible to determine whether or not it is a lesion when determining using the number of wave valleys or the number of peaks.

  Based on the result of step 2386, if PF is different from the T2 curve characteristics (2387), the corresponding slice is determined to be a lesion slice, and each image type such as a morphological image and a T2 image related to the slice is labeled and stored. (Step 2388), the process of Step 238 is exited. If PF matches the T2 curve characteristic in step 2387, it is determined by checking whether allpn is 0 (step 2389). If allpn is not 0, the process returns to step 2384, and the next vertical profile is repeatedly processed. If allpn is 0, the process exits from step 238.

  A second embodiment of step 238 will be described using the flow of FIG. In the second embodiment, the processing from step 2380 to step 2382 is the same as that in the first embodiment. In the present embodiment, an analysis region (hereinafter referred to as analROIs) for analyzing mean / variance and the like is obtained for ThreCT2Is (step 23810), and then the number of points pn on the subchondral bone side in analROIs is obtained, The value is reset after subtracting allpn by pn (step 23811).

  An example of how to determine the analROIs in step 23810 is shown in FIG. On the subchondral bone side, points 1202 that are adjacent to each other on one straight line 1201 are straight lines that are perpendicular to the straight line including several points (for example, five points shown in FIG. 12A). 1206 and 1207) and a region 1205 surrounded by a point 1204 on the cartilage fluid side curve / straight line 1203 is defined as one analROIs. When a curve is drawn on the subchondral bone side, as shown in FIG. 12B, an area 1210 surrounded by a straight line (1209 and 1211) perpendicular to the tangent line 1208 of two adjacent points and the cartilage fluid side curve 1210 Is one analROIs.

  The average / variance is obtained for each analROIs obtained in step 23810, and it is tested whether there is a significant difference in the mean / variance between the analROIs (step 23812). The test result is judged to determine whether or not there is a significant difference (step 23814), and it is determined whether to proceed to the next step 23814 or 23815. For the examination of the significant difference, for example, a t-test can be used. If there is a significant difference, the corresponding slice is determined to be a lesion slice, and each image type such as a morphological image and a T2 value image related to the main slice is labeled and stored (step 23814). If there is no significant difference, it is determined whether or not allpn is 0 (step 23815). If allpn is 0, the process of step 238 is exited. If allpn is not 0, the process returns to step 23810 and is repeated until the process of step 238 is completed.

  After the process of step 238 is completed, the process proceeds to step 239, and after sc is incremented, it is determined whether or not sc has been processed for all slices (step 2310). If it is determined in step 2310 that sc is all slices, the process goes to step 23 and proceeds to step 24 in FIG. If it is determined in step 2310 that sc is not all slices, the process returns to step 235 and is repeated until the process of step 23 is exited.

  In step 24, the result processed in step 23 is displayed on the display unit. An example of the result display is shown in FIG. The result display window 1301 of FIG. 13 includes a slice number display unit 1302 and an image display unit 1305 that displays an image. The slice number display part is composed of a part 1303 recommended for interpretation and a part 1304 not recommended for interpretation. The slice determined to be a lesion slice in the 23 steps is displayed on the section 1303 recommended for interpretation. For example, illustrated slice numbers 2, 3, 7, and 9 are displayed as lesion slices. A part 1304 not recommended for interpretation displays a slice that is determined not to be a lesion slice in step 23.

  For the slice numbers 1302 and 1303, it is possible to add a color color or the like for easy understanding visually. The slice number is linked to the original image group, T2 value image group, T2 value map image group, T2 value image CarT2Images of the cartilage region, or the like. The display of each image type can be combined (not shown), and the user can set the combination (not shown).

  The image display unit 1305 displays an image 1306 of the slice by selecting a slice number, clicking, or the like. The image 1306 is an example of one sheet, but is set by the user as necessary, and the image display unit 1305 can simultaneously display a plurality of types of images related to the slice.

  The 1304 can be set not to be displayed by the user's selection. For example, this can be realized by adding a display / non-display button (not shown) of 1304 to the 1301.

  Further, the PF of FIG. 8 and the analROIs of FIG. 9 are stored, and when the slice number is selected, it is displayed on the image display unit 1305 at the same time or at the same time as the image type (not shown). It may be. Further, the CarT2Images obtained in FIGS. 8 and 9 may be displayed in 3D in the slice direction.

  In the above description, the morphological image uses T2W. However, the present invention is not limited to this, and an MRI image such as a T1W image or a PDW image may be used. In addition, if the region of interest is cartilage and the characteristic of cartilage is used to determine whether it is a lesion slice, if the region of interest is another organ or tissue such as the brain or liver, replace it with the corresponding organ or tissue property, It is possible to determine a lesion slice.

DESCRIPTION OF SYMBOLS 101 ... Subject, 102 ... Static magnetic field magnet, 103 ... Gradient magnetic field coil, 104 ... RF transmission coil, 105 ... RF reception coil, 106 ... Signal detection part, 107 ... Signal processing part, 108 ... Display part, 109 ... Gradient magnetic field Power source, 110 ... RF transmission unit, 111 ... control unit, 112 ... bed, 113 ... bed driving unit, 114 ... input unit, 116 ... storage unit,
1001, 1002 ... cartilage contour, 1003 ... cartilage lower bone side and cartilage fluid side boundary,
1101, 1105 ... Profile of diseased cartilage, 1102 ... Profile of normal cartilage, 1103, 1104 ... Profile position, 1106 ... Borderline between lower bone side and cartilage fluid side of cartilage, 1107 ... Cartilage region,
1201 ... Contour of the subchondral bone side, 1202 ... Point on the contour of the subchondral bone side (pixel), 1203 ... Contour of the cartilage side, 1204 ... Point of contour (pixel) of the cartilage side, 1205 ... Analysis region, 1208: Tangent line on the subchondral bone side, 1209, 1211 ... Straight line perpendicular to the tangent line, 1210 ... Analysis area,
1301 ... Result display window, 1302 ... Slice number display section, 1303 ... Slice number display section recommended for interpretation, 1304 ... Slice number display section not recommended for interpretation, 1305 ... Image display section, 1306 ... Image,
1401, 1406, 1407 ... peripheral contour of the region of interest, 1402-1405 ... image diagram of thresholded image,
1501 ... Original image group, 1502 ... Form image, 1503 ... T binary image group,
1601 ... Lower bone side of cartilage area, 1602 ... Cartilage fluid.

Claims (15)

A magnetic resonance imaging apparatus for performing multi-slice imaging or 3D imaging,
Storage means for storing a plurality of images obtained by the multi-slice imaging or the 3D imaging and a value image created based on the plurality of images;
Setting means for setting a region of interest in any of the plurality of images;
Extracting means for extracting the region of interest from the value image;
Comprising display means for displaying slice information recommended for interpretation from the plurality of images based on information on the region of interest of the value image;
A magnetic resonance imaging apparatus. The magnetic resonance imaging apparatus according to claim 1.
The magnetic resonance imaging apparatus, wherein the value image is a T1 value image, a T1ρ value image, or a T2 value image. The magnetic resonance imaging apparatus according to claim 1 or 2, further comprising:
A determination means for determining the presence or absence of a lesion in the region of interest of the value image;
The display unit displays slice information recommended for interpretation from the plurality of images based on a determination result of the determination unit. The magnetic resonance imaging apparatus according to claim 3.
Judgment means for judging the presence or absence of the lesion,
Means for comparing whether the pixel value of the region of interest extracted from the value image is within a normal range, and setting the pixel value outside the normal range to zero;
A magnetic resonance imaging apparatus comprising: means for determining presence / absence of a lesion based on a pattern of a region of interest in which a pixel value outside the normal range is zero. The magnetic resonance imaging apparatus according to claim 4.
The means for determining the presence or absence of a lesion includes a means for detecting whether or not there is a region having a pixel value of zero within the region of interest, and determining a lesion when there is a region that is zero. Resonance imaging device. The magnetic resonance imaging apparatus according to claim 5.
The means for determining the presence or absence of the lesion detects whether there is a region where the pixel value is zero within the region of interest, and if there is no region where the pixel value is zero, the profile of the T1 value, T1ρ value, or T2 value And a means for determining a lesioned part when they are different from each other as compared with a normal profile. The magnetic resonance imaging apparatus according to any one of claims 1 to 6,
The extracting means for extracting the region of interest uses all the images of the plurality of images using the coordinates of the region of interest set by the setting unit and the characteristics of the region of interest of the value image in a part of the plurality of images. A magnetic resonance imaging apparatus characterized by automatically extracting a region of interest. The magnetic resonance imaging apparatus according to any one of claims 1 to 7,
2. The magnetic resonance imaging apparatus according to claim 1, wherein the slice information is a slice number. The magnetic resonance imaging apparatus according to any one of claims 1 to 8,
The magnetic resonance imaging apparatus, wherein the region of interest is a cartilage, brain, liver, or heart, and the lesion is a cartilage, brain, liver, or heart lesion, respectively. A method of operating a magnetic resonance imaging apparatus for performing multi-slice imaging or 3D imaging,
From the storage means, a multi-slice imaging was Tsu row, or to expand the 3D image 3D imaging Multislice image, and obtaining a multi-slice image,
Extracting a region of interest for all slices of the multi-slice with an extraction means ;
A step of determining presence / absence of a lesion by using a normal characteristic that is not a lesion in the region of interest of the value image for all the regions of interest of the extracted value image by the determination unit ;
A step of displaying a slice to be interpreted as a recommended slice based on a result of the determination by a display means ;
A method of operating a magnetic resonance imaging apparatus comprising : The method of operating a magnetic resonance imaging apparatus according to claim 10,
Extracting the region of interest comprises
Selecting a value image for each slice and storing it as a value image group;
Selecting an ROI setting image for each slice and storing it as an ROI setting image group;
Selecting at least the first slice and the last slice from the ROI setting image group as reference images;
A user setting a region of interest in a reference image;
Estimating the region of interest of the ROI setting image excluding the reference image based on the region of interest set in the reference image;
A method of operating a magnetic resonance imaging apparatus comprising : The method of operating a magnetic resonance imaging apparatus according to claim 10 or 11,
Determining the presence or absence of the lesion,
Applying the set or estimated region of interest to the value image to extract a value image of the region of interest;
Comparing whether the pixel value of the extracted region of interest is within a normal range, and setting the pixel value outside the normal range to zero;
The normal range of the pixel values based on the pattern of the region of interest is zero, operation method for a magnetic resonance imaging apparatus characterized by comprising a step of determining whether the lesion. The method of operating a magnetic resonance imaging apparatus according to claim 12,
The step of determining the presence or absence of the lesion includes the step of detecting whether or not there is a region where the pixel value is zero within the region of interest, and determining that the region is zero is a lesion portion A method of operating a resonance imaging apparatus. The method of operating a magnetic resonance imaging apparatus according to claim 13,
The step of determining the presence or absence of the lesion detects whether there is a region where the pixel value is zero within the region of interest. If there is no region where the pixel value is zero, the profile of the T1 value, T1ρ value, or T2 value And a method of operating the magnetic resonance imaging apparatus, comprising the step of determining a lesion when the two are different from each other as compared with a normal profile. The method of operating a magnetic resonance imaging apparatus according to any one of claims 10 to 14,
The method of operating a magnetic resonance imaging apparatus, wherein the region of interest is cartilage, brain, liver, or heart, and the lesion is a lesion of cartilage, brain, liver, or heart, respectively.

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