JP6510170B2 - Medical diagnostic imaging system - Google Patents

Description

  The embodiment of the present invention relates to a medical diagnostic imaging apparatus.

  For example, a magnetic resonance imaging apparatus (MRI) magnetically excites nuclear spins of an object placed in a static magnetic field with a high frequency signal of a Larmor frequency, and automatically induced decay occurs along with the excitation. An image inside the subject is obtained from the signal or echo signal. By adopting such a method, acquisition of a medical image by MRI is extremely effective as a method for noninvasively obtaining an anatomical tomogram of a subject.

  However, each pixel value of a medical image obtained by multi-slice imaging using MRI is strongly influenced by the volume of the subject in the medical image or the contents such as an organ, so even under the same imaging conditions. Even in the case of the image taken with the above, it varies for each medical image and shows different values. This point is, for example, a point different from a CT value (for example, a bone, water, or the like which takes a value determined depending on an object) in an image obtained by an X-ray CT apparatus (computed tomography: computed tomography).

  Therefore, in the medical image obtained by MRI, the gray value of the pixel is set by the setting of the display unit (display window) so that the part (part) to be the diagnostic purpose can be clearly and clearly observed. For example, when the display gradation of the display unit is 256 gradations, “0 (dark)” to “255 (bright)” are set. The settings of the display window are the width of the pixel value to be converted to the gray value (Window Width (hereinafter referred to as “WW”)) and the pixel value (Window level (Window level) that is the center value of the gray value. Level) (hereinafter referred to as "WL")), and is performed by setting.

  In setting WW / WL, for example, all pixel values are acquired and set in units of medical images and series. However, since all signals are taken into consideration in setting, there is a possibility that the contrast of the region that the user of interest wants to observe may not necessarily be optimal. In addition, all signals include noise and signals in areas other than the subject, which may result in a medical image that is not intended by the user.

  Therefore, it is also conceivable to set WW / WL using, for example, a preset equation for setting WW / WL (see Patent Document 1).

Japanese Patent Application Laid-Open No. 2004-057389

  However, in the invention disclosed in Patent Document 1, the following points are not taken into consideration.

  That is, since an equation for setting WW / WL is provided in advance, naturally, the setting of WW / WL applied to the equation is performed. However, as described above, for example, it is likely that the pixel values in medical images captured using MRI show different values even in medical images obtained by imaging under the same conditions. If this is taken into consideration, if WW / WL is set by substituting into a formula uniformly, it may occur that the setting does not necessarily provide the user with an optimal medical image. In particular, although the region of interest changes depending on the subject (medical image), it is required to be able to set the optimum WW / WL in accordance with the change.

  The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to simply set the optimum WW / WL in the entire medical image in accordance with the region of interest set by the user. An object of the present invention is to provide a medical image diagnostic apparatus capable of easily setting an optimum WW / WL for subsequent medical images by holding information on a region of interest.

The feature of the invention according to claim 1 is that in the medical image diagnostic apparatus, a region of interest setting unit for setting a region of interest on a medical image based on a setting instruction of a region of interest on a medical image by a user; the contrast of the realm that includes an external area of the region of interest compared on the basis of the pixel value a on the inside and a medical image, so as to emphasize the internal contrast of the region of interest in response to a result of comparison, window width and An image processing unit that sets tone conversion parameters including a window level, sets tone conversion parameters in an area outside the region of interest on the medical image, and performs tone conversion processing inside and outside the region of interest And. The image processing unit further includes a window width / window level setting unit for setting a window width and window level for performing tone conversion processing inside and outside the region of interest, and the window width / window level setting unit The difference between the maximum pixel value and the minimum pixel value in the above is set to be approximately the window width inside the region of interest.

It is a block diagram showing an internal configuration of a medical image diagnostic device in an embodiment. FIG. 3 is a block diagram showing an internal configuration of an image processing unit in the embodiment. It is a flowchart which shows the flow which sets WW / WL in embodiment. It is explanatory drawing which shows the example of the medical image displayed on a display part when setting WW / WL in embodiment. In the flow which sets up WW / WL in an embodiment, it is a flow chart which shows an example of setting of a field of interest. It is a conceptual diagram used when demonstrating the setting of WW / WL in embodiment. It is a conceptual diagram used when demonstrating the setting of WW / WL in embodiment. It is a flowchart which shows the flow which sets WW / WL in embodiment.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a block diagram showing an internal configuration of the medical image diagnostic apparatus 1 according to the embodiment.

  In the medical image diagnostic apparatus 1, a central processing unit (CPU) 1a, a read only memory (ROM) 1b, a random access memory (RAM) 1c, and an input / output interface 1d are connected via a bus 1e. An input unit 1 f, a display unit 1 g, a communication control unit 1 h, a storage unit 1 i, a removable disk 1 j, and a drive unit control unit 1 k are connected to the input / output interface 1 d. The drive unit control unit 1 k controls each drive unit provided in the medical image diagnostic apparatus 1.

  The CPU 1a reads and executes a boot program for activating the medical image diagnostic apparatus 1 from the ROM 1b based on an input signal from the input unit 1f, and reads out various operating systems stored in the storage unit 1i. The CPU 1a also controls various devices based on input signals from other external devices (not shown in FIG. 1) via the input unit 1f and the input / output interface 1d. Furthermore, the CPU 1a reads a program and data stored in the RAM 1c, the storage unit 1i, etc. and loads the program and data into the RAM 1c, and based on the program command read from the RAM 1c A processing device that realizes a series of processing such as setting, image processing, data calculation, and processing.

  The input unit 1 f is configured by an input device such as a keyboard or a dial through which an operator (for example, a user such as a doctor or an inspection technician) of the medical image diagnostic apparatus 1 inputs various operations. A signal is generated and transmitted to the CPU 1a via the bus 1e.

  The display unit 1g is, for example, a liquid crystal display. The display unit 1g receives an output signal from the CPU 1a via the bus 1e and, for example, an image or the like necessary for setting conditions for performing a processing request of a certain image to the medical image diagnostic apparatus 1, or a processing result of the CPU 1a Display etc.

  The communication control unit 1 h is a means such as a LAN card or a modem, and is a means capable of connecting the medical image diagnostic apparatus 1 to a communication network such as the Internet or a LAN. Data transmitted to and received from the communication network via the communication control unit 1 h is transmitted to and received from the CPU 1 a via the input / output interface 1 d and the bus 1 e as an input signal or an output signal.

  The storage unit 1i is configured of a semiconductor or a magnetic disk, and stores programs and data executed by the CPU 1a.

  The removable disk 1 j is an optical disk or a flexible disk, and signals read and written by the disk drive are transmitted to and received from the CPU 1 a via the input / output interface 1 d and the bus 1 e.

  The region of interest setting unit 10 sets a region of interest to the user on the medical image. Specifically, a region of interest (ROI: Region Of Interest) is set by the user surrounding an area to be a target of medical examination (observation) on a medical image using, for example, an input unit 1 f such as a mouse. Hereinafter, in the drawings and in the drawings, the region of interest setting unit 10 is appropriately referred to as “ROI setting unit 10”.

  The region of interest setting storage unit 11 grasps the coordinates of the region of interest indicated by the user, and stores the coordinates (information on the region of interest). The storage destination of the information on the region of interest is, for example, the header portion of the information on the medical image for which the region of interest is set, or the storage unit 1i, or even in the region of interest setting storage unit 11. good. Hereinafter, in the drawings and in the drawings, the region of interest setting storage unit 11 will be appropriately referred to as “ROI setting storage unit 11”.

  The image processing unit 20 sets WW / WL in a medical image. In the embodiment of the present invention, when the region of interest is set via the ROI setting storage unit 10, the image processing unit 20 automatically performs WW / WL setting using the information on the region of interest. Further, even if the information on the region of interest to be used relates to the region of interest directly set by the user, or, as described later, for example, as in follow-up observation for the same subject, imaging under the same conditions It may be information on a region of interest that has already been set for the target region.

  FIG. 2 is a block diagram showing an internal configuration of the image processing unit 20 in the embodiment. The image processing unit 20 includes a reception unit 21, a window width / window level setting unit 22 (hereinafter referred to as “WW / WL setting unit 22” as appropriate), a determination unit 23, an image alignment unit 24, and a transmission unit. And 25. The function of each unit constituting the image processing unit 20 will be described together with the setting of the region of interest (ROI) and the setting of WW / WL.

  In addition, although the medical image diagnostic apparatus 1 may be installed in a medical institution by the apparatus alone, for example, a hospital information management system (HIS: Hospital Information System), a radiation department information management system (RIS: Radiological Information System) And a medical image management system (PACS: Picture Archiving Communication System) may be part of various management systems built in a medical institution.

  FIG. 3 is a flowchart showing a flow of setting WW / WL in the embodiment. In the embodiment of the present invention, first, the setting of the region of interest (ROI) is performed by the user (ST1).

  As described above, the setting of the region of interest is performed using the input unit 1 f by determining the region in which the user is interested, that is, the region to be examined (observed) and the region. The ROI setting unit 10 performs setting processing according to a user's instruction, and transmits, to the image processing unit 20, the fact that the region of interest has been set and information on the region of interest.

  FIG. 4 is an explanatory view showing an example of the medical image MI displayed on the display unit 1g when setting WW / WL in the embodiment.

  The medical image MI in FIG. 4 is a medical image captured around the neck of the subject H. For the purpose of understanding, the appearance of the subject H is indicated by a two-dot chain line. In the medical image MI, jaws and shoulders are shown just around the neck.

  Also shown as a solid line in a tubular form are blood vessels including the left and right carotid arteries. Furthermore, a hatched area is shown above the medical image MI, which is a region of interest (ROI). FIG. 4 shows a state in which the user has set the region of interest in the relevant part of the medical image MI using the input unit 1 f. The shaded area is an area of interest for the user to perform a medical examination (observation). Therefore, for the medical image diagnostic apparatus 1, the inside of the region of interest is a region clearly shown under the balance with the entire medical image MI.

  Although the setting of the region of interest (ROI) is set by the user as described above, the region-of-interest setting unit 10 is configured to be able to set the region of interest on the inclined rectangle or straight line. Here, it is clarified that the “tilted” region of interest can be set in particular, although the region of interest is set so as to straddle the blood vessel to be examined (observed), This is because they are not necessarily displayed vertically or horizontally. As a matter of course, it is possible to set the region of interest on the medical image vertically or horizontally.

  The setting of the region of interest can be set by the user specifying the region as described above. That is, in general, when setting the region of interest by the user using the mouse as the input unit 1 f to set the region, the user places the mouse pointer at a predetermined position. Then, while pressing the left button of the mouse, the area is designated by moving the mouse starting from that point.

  Therefore, in addition to the designation of such a region, for example, a region which is a region of interest may be set only by designating a “point”. Specifically, the user places the mouse pointer at a predetermined position and clicks. The region-of-interest setting unit 10 that receives the designation of the “point” automatically sets a region having a predetermined area starting from the point. This starting point may be any point at the four corners of the area or a point indicating the center of the area. When setting the region of interest, the user can set the region of interest more simply because the region of interest is set simply by specifying the point that is the starting point on the medical image. In addition, it is possible to set a more appropriate region as a region of interest by rotating the region of interest set in this manner on a medical image or the like.

  Furthermore, it is also possible to set a region of interest using a model of a medical image in which the region of interest is predetermined. FIG. 5 is a flowchart showing an example of setting of a region of interest in the flow of setting WW / WL in the embodiment.

  The medical image in which the region of interest is set by the user is an image obtained by imaging the subject. Of course, imaging conditions are set for imaging the medical image. As this imaging condition, for example, an imaging site such as a neck and a stomach can be mentioned. Furthermore, the region of interest set for each imaging site does not differ significantly depending on the user. That is, it is possible to define an area that may be set as an area of interest in advance for each imaging site.

  Therefore, one or a plurality of regions of interest are defined in advance on the medical image, and the medical image is stored as a medical image model when setting the regions of interest. The user can reduce the burden of setting the region of interest by setting the region of interest while using such a medical image model.

  The flow of setting of a specific region of interest (ROI) using a medical image model will be described using FIG. First, when the user starts the setting process of the region of interest, the ROI setting unit 10 confirms imaging conditions at the time of imaging in the medical image for setting the region of interest (ST1-1). This is a condition for searching for an optimal medical image model in setting a region of interest on a medical image. Then, a medical image model that matches the confirmed imaging condition is searched (ST1-2). The medical image model is stored, for example, in the storage unit 1i.

  Then, when a medical image model optimal for use as a model is retrieved, alignment is performed between the medical image for setting the ROI and the retrieved medical image model (ST1-3). This alignment is required, for example, because the region of interest can not be set at an appropriate position if the scale of the medical image and the medical image model in which the region of interest is set are different. In addition, about alignment of an image, since it plans to perform using a well-known technique, it does not demonstrate in particular here.

  When alignment is completed, settable ROIs (regions of interest) are displayed on the medical image (ST1-4). The displayed region of interest is a region of interest defined in the medical image model. The user selects a region of interest considered to be optimal from among the displayed regions of interest (ST1-5). The ROI setting unit 10 confirms and sets the selected region of interest (ROI) (ST1-6). This completes the setting of the region of interest using the medical image model (ST1-7).

  A case may be considered where it is desired to set a region of interest different from the region of interest defined in the medical image model displayed on the medical image. In such a case (NO in ST1-5), the user newly sets a region of interest (ROI) (ST1-8). This completes the setting of the region of interest.

  Next, the image processing unit 20 first sets WW / WL so that the contrast in the set region of interest is emphasized (ST2). The setting of WW / WL is performed immediately after the region of interest is set. With such processing, WW / WL can be set in real time following the setting of the region of interest. This leads to good operability of the user.

  Here, "to enhance the contrast" means (set) that the medical image in the region set as the region of interest can be most clearly seen by the user. That is, since the medical image itself is displayed in black and white, the display is clarified by emphasizing the edge serving as the black and white boundary. Since the setting of WW / WL is originally performed so that the pixel value on the medical image becomes a value suitable for medical examination (observation) as described above, here, first of all, the user is particularly interested Setting of WW / WL in a certain area.

  Specifically, the setting of WW / WL in the region of interest is calculated by substituting necessary values into the following preset equations in the WW / WL setting unit 22 of the image processing unit 20.

  First, the maximum pixel value in the region of interest is, for example, “Local Max”. On the other hand, the minimum pixel value in the region of interest is, for example, "Local Min". These maximum pixel values or minimum pixel values in the target medical image are grasped in the WW / WL setting unit 22. And WW is calculated | required by following (1) Formula, for example. Moreover, WL is calculated | required by following (2) Formula, for example.

  As described above, WW and WL in the region of interest are set.

  Next, WW / WL in a region outside the region of interest (ROI) is set on the medical image (ST3). It can be said that it is only in the area set as the region of interest that the user focuses most in medical examination (observation) on medical images. In other words, it can be said that the setting of the region of interest is performed because it is the region of most interest, and it is considered sufficient to set the WW / WL only for the region concerned.

  However, on the same medical image, the contrast is adjusted only in the region of interest, and even if only the region is set to be easy to see, it may be considered that the entire medical image is difficult to see. Therefore, after setting WW / WL in the region of interest, WW / WL is set based on the pixel values of the entire medical image in consideration of the balance with the region of interest even in the region outside the region of interest.

  The setting of WW / WL outside the region of interest is performed in the WW / WL setting unit 22 using the following equation. First, as a premise, the maximum pixel value in the entire medical image is, for example, “Max”. On the other hand, the minimum pixel value in the entire medical image is, for example, "Min". The maximum pixel value or the minimum pixel value is grasped in the WW / WL setting unit 22. Then, in order to obtain WW, first, a comparison value of the contrast in the entire medical image and the contrast in the region of interest is obtained by the equation (3).

  Here, the purpose of finding the comparison value between the contrast in the entire medical image and the contrast in the region of interest is to set the WW / WL in the entire medical image in balance with the WW / WL in the region of interest set earlier. It is. When the comparison value Ratio1 is obtained using the equation (3), it is then determined whether the comparison value is larger than a preset value (Ratio1> constant value).

  The method of determining the constant value may be determined in advance, or may be set manually by the user. That is, considering the adjustment of contrast in the region outside the region of interest, the contrast in the region of interest can be obtained by adjusting the entire range so that it has a certain width even if it is a constant value. Some degree of easiness to see, which is a relationship between the contrast and the contrast outside the region of interest, can be secured.

  As a result, when the comparison value is larger than the preset value, WW is set based on the above-mentioned equation (1).

  On the other hand, if the comparison value is the same as or smaller than the preset value, WW is set using the following equation (4).

  In addition, about WL, the same value as WL set in the region of interest is used. Because WL is a pixel value which is a value at the center of the gray value, it is considered that there is no difference between the region of interest and the region of interest on the medical image.

  The method of setting the WW / WL of the entire medical image other than the region of interest described above will be further described using FIGS. 6 and 7. 6 and 7 are conceptual diagrams used when describing the setting of WW / WL in the embodiment.

  Here, the vertical axis indicates the number of pixels, and the number of pixels increases in the direction of the arrow. The horizontal axis indicates pixel values, and the horizontal axis increases to the right (in the direction of the arrow). A straight line indicated by two solid lines corresponds to Ratio 1. Further, a straight line indicated by two broken lines corresponds to the above-described "constant value". Therefore, it can be said that the constant value is a value having a certain degree of width.

In the conceptual diagram shown in FIG. 6, it is shown that the value of Ratio 1 is larger than the value of the constant value. In this case, as described above, WW is set using equation (1). Therefore, in this case , the difference between the maximum pixel value and the minimum pixel value in the region of interest is set as WW, and the center of the width indicated by WW is set as WL . In other words, setting the difference between the maximum pixel value and the minimum pixel value as WW enables display with enhanced contrast.

On the other hand, the conceptual diagram shown in FIG. 7 is the case of (Ratio1 ≦ constant value), unlike the case of FIG. In this case, a value obtained by multiplying the difference between the maximum pixel value and the minimum pixel value in the entire medical image by a fixed value is set as WW, and the center of the width indicated by WW is set as WL. By setting in this way, the contrast in the region of interest and the contrast outside the region of interest are balanced, and as a result, the medical image in the region set as the region of interest becomes clear.

  Further, the WW / WL setting unit 22 includes the first setting method which is a setting method of WW inside the region of interest as described above, and the second setting method which is a setting method of WW in the region outside the region of interest. Switch the WW setting method appropriately for each.

  As described above, WW / WL in the entire medical image balanced in the region of interest and the region outside the region of interest is set. Here, the ROI setting storage unit 11 stores, for example, information (setting information) on the region of interest used in setting WW / WL in a header portion of information on a medical image. Alternatively, it may be stored in the storage unit 1i or in the ROI setting storage unit 11.

  The information on the region of interest is stored, as will be described later, for use in setting WW / WL again for the medical image on the subject similar to the medical image. Here, although information on the region of interest is stored at this stage (step), for example, it may be stored immediately after the setting of the region of interest (after step ST1).

  Next, setting of WW / WL for a medical image used when medical examination (observation) is continuously performed on the same subject such as follow-up observation will be described. Follow-up observation is performed on the same site of the same subject. Therefore, it is preferable to set the WW / WL after setting the region of interest again at the same position as the region of interest in the medical image observed as previously as possible. By setting the WW / WL in this manner, especially when the previous medical image and the medical image to be used this time are aligned and compared, the difference becomes clear and the user observes the region of interest Becomes easier.

  Therefore, in the embodiment of the present invention, after setting the region of interest as follows, the setting of WW / WL is performed. Here, a medical image previously set with a region of interest and used for medical examination or the like is referred to as a "first medical image". Then, a medical image to be displayed which is to be newly set for the region of interest is represented as a “second medical image”.

  FIG. 8 is a flowchart showing a flow of setting WW / WL in the embodiment. First, the second medical image for which the setting of the region of interest has not been made is displayed on the display unit 1g (ST11). Next, when setting the region of interest in the second medical image, the determination unit 23 of the image processing unit 20 checks whether information (setting information) on the region of interest serving as a reference is stored in any of them. (ST12).

  When the information on the region of interest is already stored (YES in ST12), first, the medical image in which the region of interest is set by the image alignment unit 24 to use the information on the region of interest (1) medical image and the second medical image are aligned. Alignment of both medical images is performed even if the region of interest is set in the second medical image with information on the region of interest set in the first medical image without aligning the positions of both medical images. As a result, it is not possible to set an appropriate WW / WL in the area required by the user.

  Therefore, the image alignment unit 24 aligns the medical image (first medical image) with the second medical image including information on the region of interest to be referred to when setting the same region of interest again this time (the first medical image). ST13). The image alignment is scheduled to be performed using a known technique, and thus will not be described here.

  When the alignment of the first medical image and the second medical image is completed in the image alignment unit 24, next, setting of a region of interest is performed on the second medical image (ST14). In setting the region of interest, information on the region of interest at the time of setting in the first medical image is used, and at the position of the region of interest set in the first medical image, the region of interest of the second medical image is also used. It is set.

  After the region of interest is set, as described above, adjustment of contrast (setting of WW / WL) in the region of interest in the second medical image and setting of WW / WL in the entire second medical image are performed. It is performed (ST2, 3). Then, the information on the region of interest set in the second medical image is stored in the header portion or the like of the information on the second medical image (ST4).

  As described above, not only the position of the region of interest but also the WW / WL value set in the first medical image is used as it is in the medical image diagnostic apparatus 1 (MRI). This is because captured medical images do not become identical medical images even if they are captured under the same conditions. Therefore, although the position of the region of interest is the same, the setting of WW / WL is performed again.

  When the determination unit 23 determines that there is no information on the existing region of interest (NO in ST12), the region of interest is newly added to the medical image displayed by the ROI setting unit 10 based on the determination result. Setting (ST1). The setting of WW / WL after this is as described above.

  As described above, first, it is possible to provide a medical image diagnostic apparatus capable of easily setting the optimum WW / WL in the entire medical image in accordance with the region of interest set by the user.

  That is, while setting a region of interest by the user, setting of the region of interest alone will automatically set WW / WL only for the region of interest. Therefore, since it is sufficient for the user to set only the region of interest, the WW / WL setting process is simplified. Moreover, not only the setting of WW / WL in the region of interest but also setting of WW / WL of the entire medical image to balance with the region of interest, it is possible to clearly see the region of interest, and the medical image The contrast can be adjusted to an image that is easy to see as the entire medical image, which is well-balanced with other regions in.

  Furthermore, by holding information on the region of interest, it is possible to provide a medical image diagnostic apparatus capable of easily setting the optimum WW / WL for the subsequent medical image.

  That is, when medical examination (observation) is continuously performed on the same region of the same subject such as follow-up observation, if it is assumed that the region of interest has to be set each time in order to set WW / WL, There is a possibility that the position may shift. Therefore, once the region of interest is set, the setting of the region of interest is performed at the same position using information (setting information) on the region of interest. Furthermore, by aligning the medical image having information on the region of interest with the medical image for setting the region of interest newly before setting the region of interest, setting the region of interest at the same position without deviation And subsequent WW / WL configuration will be more easily done.

  Although the embodiments of the present invention have been described, this embodiment is presented as an example and is not intended to limit the scope of the invention. This embodiment can be implemented in other various forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. This embodiment and its modifications are included in the scope and the gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

1 medical image diagnostic apparatus 10 ROI setting unit 11 ROI setting storage unit 20 image processing unit 21 reception unit 22 WW / WL setting unit 23 determination unit 24 image alignment unit 25 transmission unit

Claims (7)

A region of interest setting unit that sets the region of interest on the medical image based on a setting instruction of the region of interest on the medical image by the user;
Emphasizing the internal contrast of the region of interest in accordance with a result of the A on the inside and the medical image of the region of interest compared based contrast realm that includes an external area of the region of interest on the pixel values were compared Setting the gradation conversion parameters including the window width and the window level, and setting the gradation conversion parameters in the region on the medical image and outside the region of interest; comprising of an image processing unit that performs gradation conversion processing, and
The image processing unit includes a window width / window level setting unit that sets the window width and the window level that perform tone conversion processing inside and outside the region of interest.
The window width / window level setting unit sets the difference between the maximum pixel value and the minimum pixel value in the region of interest to be substantially the window width in the region of interest. Medical diagnostic imaging system.   The image processing unit obtains the contrast by obtaining a difference between a maximum pixel value and a minimum pixel value in each of an area including the area inside the region of interest and on the medical image and outside the region of interest. The medical image diagnostic apparatus according to claim 1, which is to be compared. The region of interest setting unit is configured to be able to set the region of interest on a sloped rectangle or a straight line,
The medical image according to claim 1 , wherein the window width / window level setting unit obtains the window width and the window level immediately after the region of interest is set by the region of interest setting unit. Diagnostic device. The region of interest setting unit sets the region of interest based on the region of interest indicated in a medical image model that is a model of the medical image in which the region of interest is set. The medical image diagnostic apparatus according to any one of claims 1 to 3 . The window width / window level setting unit sets a difference between a maximum pixel value and a minimum pixel value inside the region of interest, and a difference between a maximum pixel value and a minimum pixel value of a region including a region outside the region of interest. The medical image diagnostic apparatus according to any one of claims 1 to 4, wherein the window width outside the region of interest is set based on the comparison result of (4) . The window width / window level setting unit
A first setting method for setting the difference between the maximum pixel value and the minimum pixel value inside the region of interest to be substantially the window width, and the maximum pixel value and the minimum pixel of the region including the region outside the region of interest The medical image diagnostic apparatus according to any one of claims 1 to 5, wherein a second setting method of setting based on a value is switched. It further comprises a region-of-interest setting storage unit for storing information on the setting of the region of interest set by the region-of-interest setting unit,
The image processing unit
A determination unit that determines the presence or absence of information related to the setting of the region of interest stored in the region-of-interest setting storage unit;
As a result of the determination by the determination unit, when the information on the setting of the region of interest is stored, the first medical image in which the region of interest is set to set the region of interest and the region of interest newly An image alignment unit for performing alignment with a second medical image in which a region of interest is set based on information on setting of
The medical image diagnostic apparatus according to any one of claims 1 to 6 , comprising:

Images