JP4356414B2 - Biological tissue multidimensional visual device - Google Patents

Description

  The present invention relates to a biological tissue multidimensional visual apparatus using an ultrasonic diagnostic apparatus or the like.

  The ultrasonic diagnostic apparatus is configured to display a tomographic image of a biological tissue in a linear scanning direction plane of the probe by applying a linear scanning ultrasonic probe to the surface of the biological tissue. For example, when observing or visualizing a certain tissue of the human body, the probe of the ultrasonic diagnostic apparatus is applied to the body surface close to the tissue, a pulsed ultrasonic wave is emitted, and the intensity of the reflected ultrasonic wave is measured on the time axis. To display. One tomographic image is obtained by linearly scanning the above-described ultrasonic wave from the probe. In order to diagnose the entire tissue, a large number of tomographic images are obtained while moving the probe in a direction perpendicular to the linear scanning direction, and a judgment is made visually from these many tomographic images.

  Diagnosis using conventional ultrasonic diagnostic equipment has been specialized in diagnosis because diagnosis and diagnosis of pathology and lesions have been made by diagnosing a large number of tomographic images by a doctor or the like as described above. A high degree of experience and skill are required, and it is necessary for doctors with special training to read tomographic images. That is, the conventional ultrasonic diagnostic apparatus is used for diagnosis by a specialist doctor decoding an image.

  In order to eliminate such inconvenience, the tomographic image data from the ultrasonic diagnostic apparatus is image-processed by a computer to create a two-dimensional image or a three-dimensional image, and this is used as a tomographic image of a desired cross section based on the tomographic image data. A multi-dimensional visual device has been proposed by the present applicant and is publicly known so that a living tissue can be easily observed without special experience by displaying it on the same screen (for example, Patent Document 1). And 2).

  A technique for displaying blood vessels using such a multidimensional visual device is also known (for example, Patent Documents 3 and 4). Patent Document 3 describes a technique for specifying a blood vessel of interest and distinguishing it from others, and Patent Document 4 describes a three-dimensional display method of blood vessels.

Japanese Patent No. 2785636 Japanese Patent No. 2785679 JP-A-7-178090 JP 2000-300555 A

  However, as described in Patent Documents 3 and 4, it is very difficult to grasp the positional relationship between the blood vessel and other living tissue simply by displaying the blood vessel on the screen.

  Accordingly, an object of the present invention is to provide a biological tissue multidimensional visual device capable of easily grasping the positional relationship between a blood vessel and another biological tissue.

  According to the present invention, ultrasonic diagnostic means for forming ultrasonic tomographic image data composed of a plurality of pixel data arranged in the ultrasonic traveling direction and the ultrasonic scanning direction for each of a plurality of parallel cross sections of the living tissue. A storage means for storing tomographic image data for each cross section formed by using the ultrasonic diagnostic means, and a first interest for setting at least one first region of interest for extracting a blood vessel for each cross section Of the tomographic image data of each cross-section stored in the storage unit, a second region-of-interest setting unit for setting a second region of interest for extracting a bone tissue for each cross-section, and a storage unit First calculation means for obtaining one-dimensional image data relating to a blood vessel for each cross section by performing arithmetic processing on pixel data existing in one region of interest along the ultrasonic traveling direction, and stored in a storage means A second process for obtaining one-dimensional image data relating to bone tissue for each cross section by performing arithmetic processing on pixel data existing in the second region of interest among the tomographic image data of each cross section along the ultrasonic wave traveling direction. A two-dimensional image from the calculated one-dimensional image data for a plurality of cross sections related to blood vessels and a two-dimensional image from the determined one-dimensional image data for a plurality of cross sections related to bone tissue on the same screen. A biological tissue multidimensional visual device including display means for displaying is provided.

  Since the two-dimensional image related to the blood vessel and the two-dimensional image related to the bone tissue are combined and displayed on the same screen, the positional relationship between the blood vessel and the bone tissue can be easily grasped.

  The first region of interest setting means is preferably closed region setting means for setting at least one local closed region for each cross section. At least one local closed region is set for each cross section, and this becomes a region of interest, so that it is possible to eliminate the influence of biological tissue other than the desired blood vessel, spurious images of ultrasonic waves, acoustic noise, and the like. As a result, only blood vessels can be extracted and displayed clearly.

  The closed region setting means sets at least one local closed region in all the remaining cross sections by interpolation calculation from at least one local closed region in at least two specific cross sections arbitrarily set by the operator. It is preferable that the setting means. For all cross sections, for example 150 cross sections, it is cumbersome for the operator to set at least one local closed region, but only at least two specific cross sections, for example 3-5 cross sections, are set and the rest are interpolated By automatically setting by calculation, the burden on the operator is greatly reduced, and the operability is greatly improved.

  More preferably, the closed area setting means is a setting means for setting at least one local closed area having a rectangular shape or an elliptical shape.

  The first calculation means calculates the luminance value of the low-luminance portion of the pixel data along the ultrasonic traveling direction among the pixel data existing in the closed region, and obtains one-dimensional image data for each cross section. It is also preferable to be a means.

  The first calculation means inverts the luminance value of the pixel data existing in the closed region, and when the inverted luminance value is equal to or less than a predetermined threshold, sets the luminance value to zero, and then advances the ultrasonic wave in the closed region. More preferably, it is a calculation means for obtaining an average luminance value of pixel data along the direction and obtaining one-dimensional image data for each cross section.

  It is also preferable that the second region-of-interest setting unit is a band-shaped region setting unit that sets a band-shaped region along the ultrasonic scanning direction for each cross section.

  The second calculation means obtains the luminance value of the high-luminance portion of the pixel data along the ultrasonic wave traveling direction among the pixel data existing in the band-like region, and obtains one-dimensional image data for each cross section. It is preferable that it is a calculation means.

  The second calculation means obtains the average luminance value of the portion where the added value of the predetermined number of pixels along the ultrasonic wave traveling direction of the pixel data existing in the band-like region is the maximum for each cross section. More preferably, the calculation means obtains the one-dimensional image data.

  It is also preferable that the second calculating means is a calculating means for obtaining a luminance value in consideration of the acoustic shadow and obtaining one-dimensional image data for each cross section. In this case, it is preferable that the second calculation means is set so that the luminance value is high when an acoustic shadow is present.

  Calculation in which the second calculation means obtains one-dimensional image data for each cross section by obtaining an average value of all pixel data along the ultrasonic wave traveling direction among the pixel data existing in the band-like region. It may be a means.

  The display means is preferably a display means capable of displaying both two-dimensional images and a tomographic image of a desired cross section based on tomographic image data stored in the storage means on the same screen.

  According to the present invention, since the two-dimensional image related to the blood vessel and the two-dimensional image related to the bone tissue are combined and displayed on the same screen, the positional relationship between the blood vessel and the bone tissue can be easily grasped. .

  FIG. 1 is a block diagram schematically showing a configuration of an embodiment of a biological tissue multidimensional visual device according to the present invention.

  In the figure, 10 is an ultrasonic diagnostic apparatus, and 11 is a probe of the ultrasonic diagnostic apparatus 10. This ultrasonic diagnostic apparatus 10 has a configuration of a commercially available general ultrasonic diagnostic apparatus. As shown in the figure, an oscillator 10 a that generates a high-frequency pulse voltage, and a probe 11 that amplifies the high-frequency pulse and applies it to the probe 11. A transmission amplifier 10b that sends out, a reception amplifier 10c that receives and amplifies a reflection pulse (echo signal) sent from the probe 11, a display unit 10d such as a liquid crystal display device or a CRT that displays the output of the reception amplifier 10c, and a reception amplifier 10c having a function of converting the output of 10c into a video signal, a video signal output device 10e having a buffer function of temporarily storing a video signal for one cross-sectional image, and a synchronization and oscillation frequency of a high-frequency pulse to be transmitted and a display unit 10d And a controller 10f for performing other controls such as the selection control of.

  The oscillation frequency of the oscillator 10a is selected according to, for example, whether it is a bone tissue, a soft tissue such as a muscle or a blood vessel, or a visceral organ according to the type of the inspection object 12a. Is configured so that it can be selected from, for example, 3.5 MHz, 5.0 MHz, and 7.5 MHz. Note that the probe 11 may be exchanged depending on the oscillation frequency.

  The probe 11 is a linear scanning ultrasonic probe in which a large number of piezoelectric vibrators are arranged one-dimensionally. The probe 11 is held in contact with the skin surface of the human body 12 to be examined through a water bag (not shown) or a jelly-like oil applied to the body surface. The high-frequency pulse sent from the diagnostic apparatus main body to the probe 11 is sequentially switched and applied to each one-dimensionally arranged piezoelectric vibrator, whereby an ultrasonic pulse is emitted from each piezoelectric vibrator to the living tissue of the human body 12. The The ultrasonic echo reflected from the inspection object 12a or the like in the human body 12 is applied to each piezoelectric vibrator and converted into an electric pulse to be an echo signal, which is sent to the diagnostic apparatus body.

  An output terminal of the video signal output device 10e of the ultrasonic diagnostic apparatus 10 is connected to an input interface (not shown) of the digital computer 14 such as a personal computer via an A / D converter 13 that converts an analog video signal into digital data. It is connected to the. The computer 14 includes a CPU (Central Processing Unit) (not shown), a ROM (Read Only Memory) storing a program to be described later, a RAM (Random Access Memory), an image memory, a bus connecting them, and other general It has a control circuit and generally includes an input device such as a keyboard 14a and a mouse 14b as shown in the figure, a CRT 14c, an external memory 14d and the like. The image memory temporarily stores tomographic image data sent from the ultrasonic diagnostic apparatus 10 via the A / D converter 13, and can be configured by a general RAM. In this embodiment, it has a capacity capable of storing tomographic image data for 150 slices. When data exceeding this capacity is input, it is overwritten sequentially from the head address, so that the latest image data for 150 images is always stored.

  Next, the operation of the present embodiment will be described based on the flowchart of the digital computer 14. FIG. 2 is a flowchart for explaining an ultrasonic tomographic image data capturing operation control program.

  When the operator instructs to capture ultrasonic tomographic image data using the keyboard 14a or mouse 14b, first, in step S1, the capturing operation is delayed for a predetermined time. This is to absorb the time delay from the capture instruction to the start of movement of the probe 11.

  While the operator or an automatic feeder (not shown) moves the probe 11 on the surface of the layer of the human body 12 at a constant speed along a predetermined axis, the processes in steps S2 and S3 are executed. In step S2, ultrasonic diagnosis similar to that in the prior art is performed, and ultrasonic tomographic image data for one screen, that is, one cross section, is captured and stored in an image memory in the computer. In step S3, it is determined whether or not an image has been captured in a predetermined amount. This determination may be performed by determining whether or not the number of images actually captured has reached a specified number, or by determining whether or not a predetermined time has elapsed since activation. The latter can simplify the processing content. If capturing of the designated image has not been completed, the process returns to step S2, and if completed, this capturing process ends.

  At this time, ultrasonic tomographic image data relating to a specified number of cross sections is stored in the image memory. That is, as shown in FIG. 3, tomographic image data for n different cross sections of the human body 12 is accumulated for each tomographic image in the image memory. FIG. 4 shows a three-dimensional configuration of tomographic image data of n slices (for example, 150 slices) stored in the image memory in this way.

  FIG. 5 is a flowchart for explaining the image display operation control program.

  When the operator gives an instruction to display an image using the keyboard 14a or mouse 14b, an image display processing operation is started in step S11. Next, in step S12, ultrasonic tomographic image data stored in the image memory is extracted for one image (one cross section) and temporarily stored in the RAM.

  In the next step S13, a process of cutting a low level echo portion is performed on the extracted ultrasonic tomographic image data. This process is performed to remove noise generated between the probe 11 and the skin surface, and the contents thereof will be described below with reference to FIGS. 6 and 7.

FIG. 6 is a flowchart for explaining the processing in step S13, and FIG. 7 is a diagram showing the correspondence between one cross-sectional image and its ultrasonic tomographic image data. As shown in FIG. 6, the ultrasonic tomographic image data for one cross section includes a large number of arrays arranged in a matrix of the ultrasonic scanning direction (X axis, row direction) and the ultrasonic traveling direction (Y axis, column direction). It consists of pixel data _PXY .

In step S131 in FIG. 6, the pointer is set to the head address of the ultrasonic tomographic image data in the RAM, and the pixel data _P00 is read out. Each pixel data P _XY is represented by a luminance value of 0 to 255 corresponding to the echo level, the pixel data P ₀₀ read in the next step S132, it is determined whether or less luminance value 50. If the pixel data is less than or equal to the brightness value 50 only, to re-store the luminance value of the pixel data P ₀₀ at the next step S133 to a 0 RAM. Next in step S134 Y-axis direction is incremented to the next address location corresponding to the pixel data P ₁₀ rows of (ultrasonic traveling direction, see FIG. 7). In the next step S135, it is determined whether or not the above processing has been completed for all the pixel data P ₀₁ , P ₀₂ , P ₀₃ ,..., P _0m in the Y-axis direction, and if not, the process returns to step S131. The same processing is performed on these pixel data. If completed, the address is incremented to a position corresponding to the pixel data P ₀₁ in the first row of the next column in the X-axis direction (ultrasonic scanning direction, see FIG. 7) in the next step S136. In the next step S137, it is determined whether or not the processing has been completed up to the pixel data P _n0 , P _n1 ,..., P _{nm in the} last column also in the X-axis direction. Repeat the process. If completed, the process proceeds to step S14 in FIG.

  In step S14 of FIG. 5, the coordinate value of the skin surface is detected. In this process, ultrasonic tomographic image data is sequentially checked in the traveling direction of ultrasonic waves, and a position where the difference in luminance value between adjacent pixel data is no longer 0 is detected as the skin surface. Is shown in FIG.

In step S141 in FIG. 8, the pointer is set to the head address where the ultrasonic tomographic image data in the RAM after the processing in step S13 is performed, and the pixel data _P00 is read out. In the next step S142, it is determined whether or not the difference in luminance value from the previous pixel data is zero. Only when the difference between the luminance values is not 0, it is determined that this position is the skin surface, and the coordinate value of the pixel data is stored in the RAM in the next step S143. The process proceeds to step S144 if the difference between the luminance value is 0, Y-axis direction is incremented to the next address position corresponding to the pixel data P ₀₁ rows of (ultrasonic traveling direction, see FIG. 7) . In the next step S145, it is determined whether or not the above processing has been completed for all the pixel data P ₀₁ , P ₀₂ , P ₀₃ ,..., P _0m in the Y-axis direction, and if not, the process returns to step S141. The same processing is performed on these pixel data. When the processing is completed or when the difference in luminance value is not 0 and the processing in step S143 is executed, the next row in the next column in the X-axis direction (ultrasonic scanning direction, see FIG. 7) is executed in the next step S146. It is incremented to address the location corresponding to the pixel data P _01. In the next step S147, it is determined whether or not the processing has been completed up to the pixel data P _n0 , P _n1 ,..., P _{nm in the} last column also in the X axis direction. Repeat the process. If completed, the process proceeds to step S15 in FIG.

  Through the above processing, the coordinate data of the skin surface 20 (see FIG. 7) in the ultrasonic tomographic image data is accumulated in the RAM. That is, between the probe 11 and the layer surface of the human body is only a water bag filled with water or jelly-like oil, and the ultrasonic beam emitted from the probe 11 is first reflected due to the difference in acoustic impedance. Since it is regarded as the skin surface, the position of the skin surface can be known by determining whether or not the difference in luminance value is zero.

  In step S15 in FIG. 5, it is determined whether or not all the processes in steps S12 to S14 have been completed for the designated image. If not completed, the process returns to step S12 and the same process is repeated. If completed, the process proceeds to step S16.

  In step S16, a correction curve for the skin surface is created from the coordinate data of the skin surface obtained in step S15.

  In the next step S17, the operator sets a local closed region on a plurality of specific tomographic images as the vascular region of interest. FIG. 9 is a flowchart showing the contents of the closed region setting process.

  First, in step S171, a tomographic image of a cross section designated by the operator is displayed. Next, in step S172, the operator uses the mouse 14b or the like to set a closed region by an ellipse on the tomographic image. This setting is performed by designating the center position and size of the ellipse. That is, the operator operates at least one oval closed region on the displayed tomographic image while operating the mouse 14b so as to wrap only the blood vessel to be examined as much as possible while avoiding false images and acoustic noise. Set. Specifically, when the mouse 14b is clicked, an ellipse having a prescribed size centered on the cursor position is generated and displayed. By dragging the mouse or clicking an operation button displayed on the screen, the center position and size thereof are adjusted, and the outer periphery of the blood vessel can be approached.

  FIG. 10 shows a vascular region of interest by a closed region and a bone tissue region of interest by a band-like open region in the present embodiment.

  As shown in the figure, by setting so as to wrap the blood vessels 101a and 101b in the oval closed region 100, the blood vessel region of interest can be set so as not to include other unnecessary biological tissues, false images and acoustic noise. . On the other hand, the bone tissue region of interest is set to include the bone tissues 103a and 103b in the band-like open region 102 along the ultrasonic scanning direction. FIG. 10 shows an example in which one closed region is set as the vascular region of interest, but it is obvious that two or more closed regions may be set.

As shown in FIG. 11, when the coordinates of the center position of the ellipse are C (x ₀ , y ₀ ), the major axis is a, and the minor axis is b, the ellipse equation is (x−x ₀ ) ² / a ² + ( y−y ₀ ) ² / b ² = 1. The vascular region of interest is represented as a closed region of an ellipse, and is calculated as an ellipse in image processing. However, inside the computer, the upper left corner coordinates P _C1 (x ₁ , y ₁ ) and lower right of the rectangle circumscribed by the ellipse Corner coordinates P _C2 (x ₂ , y ₂ ) are stored as region-of-interest data in this cross section. In this _{case, x 0 = (x 1 +} x 2) / 2, y 0 = (y 1 + y 2) / 2, a = (x 2 -x 1) / 2, b = (y 2 -y 1) / 2 It becomes.

  In the next step S173 of FIG. 9, it is determined whether or not the setting of the closed region as the vascular region of interest has been completed for the tomographic images of a plurality of specific cross sections, and if not set, the process returns to step S171 and the next setting is performed. The tomographic image of the cross section to be displayed is displayed, the process proceeds to step S172, and the same processing is performed.

  The setting of the closed region by the operator is performed only for at least two specific sections, for example, 3 to 5 sections, because the processing becomes complicated if performed for all sections, for example, 150 sections. As this specific section, in addition to the first section and the last section, it is possible to select a section in which the target blood vessel is inflected. Later, when a closed region of a tomographic image of another section is obtained by interpolation In addition, it is possible to automatically set a more accurate closed region.

  In step S18 of FIG. 5, from the closed regions in the tomographic images of the plurality of specific cross sections set in step S17, the closed regions in all the remaining cross sections are automatically set by interpolation calculation. FIG. 12 is a flowchart showing the contents of the closed region setting process, FIG. 13 is a diagram showing the relationship between the tomographic image of a specific cross section and the closed region of the ellipse set there, and FIG. 14 shows the interpolation calculation. It is a figure explaining.

  First, in step S181, a tomographic image of one cross section is taken out, and a setting status is detected as to whether or not a closed region is set in the tomographic image. If a closed region is set on the tomographic image, the process proceeds from step S182 to step S183, and if not set, the process proceeds to step S186. As shown in FIG. 13, since the closed region 130a is set in the first cross section 130, the process proceeds to step S183.

  In step S183, the tomographic image of the cross section 131 corresponding to the cross section 130, that is, the specific cross section 131 for which the closed area setting is performed next is taken out, and the situation of the closed area 131a set in the cross section, for example, Detect numbers etc. If the number of closed regions set in the cross section matches the number of closed regions in the tomographic image of the first cross section, the process proceeds from step S184 to step S185, and if they do not match, interpolation calculation cannot be performed. Then, the process of FIG. 12, and thus the process of step S18 of FIG. 5, is terminated, and the operator sets the closed region again.

  In step S185, an elliptical closed region is obtained by interpolation for all cross sections between the two cross sections 130 and 131 for which the closed region is set.

In this embodiment, linear interpolation is used for the interpolation calculation. That is, as shown in FIG. 14, the upper left corner coordinates P _C1130 (x ₁₁₃₀ , y ₁₁₃₀ ) of the rectangles 130 b and 131 b circumscribed by the oval closed areas 130 a and 131 a in the cross-sections 130 and 131 where the closed areas are set, and the _{P C1131 (x 1131, y 1131} ), the upper left corner coordinates _P of the rectangle 133b that ellipse closed region 133a in the section 133 to calculate the circumscribed C1133 _{(x 1133, y} 1133) is linear interpolation. Similarly, the lower right corner coordinates P of the circumscribed rectangle 133b in the cross section 133 to be calculated based on the lower right corner coordinates P _C2130 (x ₂₁₃₀ , y ₂₁₃₀ ) and P _C2131 (x ₂₁₃₁ , y ₂₁₃₁ ) of the circumscribed rectangles 130b and 131b. _C2133 (x ₂₁₃₃ , y ₂₁₃₃ ) is linearly interpolated.

By this interpolation calculation,
x ₁₁₃₃ = (n ₁ x ₁₁₃₁ + n ₂ x ₁₁₃₀ ) / (n ₁ + n ₂ )
y ₁₁₃₃ = (n ₁ y ₁₁₃₁ + n ₂ y ₁₁₃₀ ) / (n ₁ + n ₂ )
x ₂₁₃₃ = (n ₁ x ₂₁₃₁ + n ₂ x ₂₁₃₀ ) / (n ₁ + n ₂ )
y ₂₁₃₃ = (n ₁ y ₂₁₃₁ + n ₂ y ₂₁₃₀ ) / (n ₁ + n ₂ )
Coordinates P _C1133 (x ₁₁₃₃ , y ₁₁₃₃ ) and P _C2133 (x ₂₁₃₃ , y ₂₁₃₃ ) are obtained. Here, n ₁ is the number of cross sections from the cross section 130 to the cross section 133, and n ₂ is the number of cross sections from the cross section 133 to the cross section 131.

  In the next step S186, it is determined whether or not it is detected that the closed region is set for all the cross sections. If it is set, the processing of FIG. 12 is terminated. If it is not set, the process returns to step S181, and a setting state is detected as to whether or not the closed region 131a is set in the current section 131. Since the closed region 131a is set in the current cross section 131, the process proceeds from step S182 to step S183, the same processing as described above is executed, and the cross section between the cross section 131 and the corresponding cross section 132 is executed. A closed region is obtained by interpolation calculation.

  In this way, the elliptical closed region of all cross sections, for example, 150 cross sections, is set by the interpolation calculation in step S18 of FIG. Even when a plurality of closed regions are set, the elliptical closed region is set for all the cross sections by performing the same interpolation calculation. When the closed region set in this way is connected in the direction of longitudinally crossing each cross section, a tubular region including this is formed along the target blood vessel.

  In step S19 of FIG. 5, blood vessel two-dimensional image data is obtained from the ultrasonic tomographic image data. More detailed contents of step S19 are shown in FIG.

  In step S191 in FIG. 15, the luminance value D = 0 to 255 of the tomographic image data in the closed region, which is the vascular region of interest in one cross section designated by the pointer in the RAM of the computer 14, is inverted. That is, the calculation of D ′ = 255−D is performed.

  In the next step S192, it is determined whether or not the inverted luminance value D ′ is larger than a predetermined threshold value. If it is larger, the process proceeds to step S193, and the inverted luminance value D ′ is set as the luminance value of the pixel. In this case, the process proceeds to step S194 to clear the luminance value of the pixel to zero.

  In the next step S195, it is determined whether or not the above process has been completed for all the pixels in the vascular region of interest. If not, the process returns to step S192 and the same process is repeated.

  When the processing of steps S192 to S194 has been completed for all the pixels in the vascular region of interest, the process proceeds to step S196, and for each pixel row aligned in the ultrasonic scanning direction (X-axis direction) in the vascular region of interest, the ultrasound traveling direction An average value of luminance values of the pixels in the (Y-axis direction) is obtained, and this is set as one-dimensional image data in the cross section.

  Next, in step S197, it is determined whether or not such one-dimensional image data has been obtained for all cross sections. If not, the process returns to steps S191 to S196 for the next cross section and the same processing is repeated. Execute. When all the cross sections (150 cross sections) are completed, the process proceeds to step S20 in FIG.

  By the above processing, as shown in FIG. 16, two-dimensional luminance image data indicating the blood vessels 161a and 161b in the blood vessel region of interest 160 is obtained. The blood vessel is a low-luminance part as an ultrasonic tomographic image, but in this embodiment, since the luminance value is inverted, it is represented as a high-luminance part in the obtained two-dimensional luminance image data. .

  In step S20 in FIG. 5, two-dimensional image data of bone tissue is obtained from the ultrasonic tomographic image data. A more detailed content of step S20 is shown in FIG.

  In step S201 in FIG. 17, ultrasonic tomographic image data in one cross section designated by the pointer in the RAM of the computer 14 is read. Next, in step S202, pixel data corresponding to the skin and the fat layer below the specified cross section is deleted from the ultrasonic tomographic image data. The depth 192a (see FIG. 19) of the skin and the fat layer is set in advance as a variable surface correction value. Accordingly, the pixel data area to be deleted is defined by the skin surface coordinate data and the surface correction value.

  In the next step S203, the ultrasonic traveling direction (Y-axis direction) from the tomographic image data in the band-shaped open region which is the bone tissue region of interest in the cross section developed with the same width in the ultrasonic scanning direction (X-axis direction). A high luminance part is searched for and the luminance value of that part is calculated. Furthermore, the presence or absence of an acoustic shadow is determined from the luminance distribution in the band-shaped open area, and correction is performed so that the luminance value of the high-intensity part decreases in areas where no acoustic shadow exists. An average luminance value in pixels in the traveling direction (Y-axis direction) is obtained, and this is used as one-dimensional image data in the cross section.

  Hereinafter, the contents of the arithmetic processing in step S203 will be described in detail with reference to FIG.

First, the tomographic image data in the band of the bone tissue region of interest 180, the front-most pixel column in the X-axis direction, determines the value D ₁ obtained by adding the luminance values of m ₁ pixel in the Y-axis direction. D ₁ is similarly determined while shifting one pixel at a time in the Y-axis direction, and the Y-axis direction position at which D ₁ is maximum and the value D _1MAX at that time are determined. This maximum value _D1MAX is obtained in a high-luminance portion that is a portion of the target bone tissues 181a and 181b. Then, determine the value D ₂ obtained by adding the luminance value of m ₂ pixels in the Y-axis direction following the position the D ₁ is the maximum. However, when obtaining the value D _2, which may also be used outside of the tomographic image data of the band-shaped bone tissue region of interest 180. m ₁ and m ₂ are experimentally determined coefficients. For example, m ₁ = 5 and m ₂ = 20.

Next, an acoustic shadow effect coefficient Se, which is a correction coefficient based on the acoustic shadow, is calculated from Se = D _1MAX / (D _1MAX + D ₂ ). The acoustic shadow effect coefficient Se increases when an acoustic shadow exists, and decreases when it does not exist.

Thereafter, the average luminance value D in the pixel column in the X-axis direction is obtained from D = D _1MAX (k ₁ Se + k ₂ ) using the acoustic shadow effect coefficient Se and the maximum value D _1MAX . k ₁ and k ₂ are also experimentally determined coefficients. For example, k ₁ = 0.7 and k ₂ = 0.3.

  Next, the same calculation is performed on the next pixel column in the X-axis direction to obtain the average luminance value D, and the average luminance value D is obtained for all the pixel columns in the band-like bone tissue region of interest 180, thereby One-dimensional image data is obtained.

  Next, in step S204, the average luminance value D along the X-axis for the designated cross section is converted into luminance information (for example, with 256 gradations) and displayed as a single line luminance image on the CRT 14c. This corresponds to, for example, a line image along the broken line 191a in FIG.

  In the above description, one-dimensional image data of each cross section is calculated by obtaining the average luminance value D of the high luminance portion in consideration of the acoustic shadow in the band-shaped bone tissue region of interest. One-dimensional image data of each cross section may be calculated by obtaining an average value of all pixel data along the ultrasonic traveling direction (Y-axis direction). In this case, the average value can be calculated by dividing the sum of all the pixel data of each column in the region of interest by the number of pixels in that column in the region of interest. In addition, the method for obtaining one-dimensional image data of each cross section by calculating the pixel data existing in the band-shaped bone tissue region in the present invention along the ultrasonic traveling direction is limited to the above-described method. It is not a thing.

  In the next step S205, the pointer is moved to ultrasonic tomographic image data and skin surface coordinate data in the next cross section. In the next step S206, it is determined whether or not the processing in steps S201 to S205 described above has been completed for all cross sections. If not completed, the process returns to step S201 and the same process is repeated. When all the cross sections are completed, the process proceeds to step S21 in FIG.

  By the above processing, as shown in FIG. 18, two-dimensional luminance image data indicating the bone tissues 181a and 181b in the bone tissue region of interest 180 is obtained. Since the bone tissue region of interest 180 is a region that expands in the ultrasonic scanning direction (X-axis direction), not only the bone tissue is detected by the above-described processing, but also other biological tissues with high luminance and the whole A contour is also detected.

  In step S21 of FIG. 5, the two-dimensional luminance image data related to the blood vessel and the two-dimensional luminance image data related to the bone tissue obtained as described above are synthesized, and synthesized on the CRT 14c of the computer as shown in FIG. The two-dimensional luminance image 191 thus displayed is displayed like an X-ray image. In this synthesis, in the two-dimensional luminance image data related to the blood vessel, the portion where the blood vessel does not exist is replaced with the corresponding pixel data of the two-dimensional luminance image data related to the bone tissue.

  In the next step S22, as shown in FIG. 19, the tomographic image 192 for the specified cross section is the same as the two-dimensional luminance image 191 using the ultrasonic tomographic image data stored in the RAM of the computer 14. Is displayed in the screen 190. In the next step S23, a mark 197 indicating the position of the designated cross section is displayed on the side of the two-dimensional image 191, thereby making it possible to understand the correspondence between the two-dimensional luminance image and the tomographic image at a glance. Examples of the display of the mark 197 include: (1) the display color of the mark is different from the image of the other part, (2) the mark 197 is blinked, (3) the mark 197 is a broken line, a chain line, or a blinking line And so on.

  For example, a desired cross section can be specified by moving the mark 197 on the screen 190 using the keyboard 14a or the mouse 14b, and the ultrasonic tomographic image data of the specified cross section can be displayed on the screen 190. .

  As described above, in this embodiment, as shown in FIG. 19, the two-dimensional luminance image data of the target blood vessels 194a and 194b and the two-dimensional luminance image data of the bone tissues 195a, 195b and 195c are synthesized. Therefore, the positional relationship of the blood vessels 194a and 194b with respect to the bone tissues 195a, 195b and 195c can be clearly grasped. In addition, an elliptical closed blood vessel region 193 that wraps only the blood vessels as close as possible to the outer circumferences of the blood vessels 194a and 194b is provided in each cross section, and the closed region 193 thus set is arranged in a direction that crosses each cross section longitudinally. By connecting, a tubular region that includes this is formed along the blood vessel, and by performing calculations in such a tubular blood vessel region of interest 193, unnecessary biological tissue, spurious images and acoustic noise can be removed. Image processing with pixel data not included is possible, and only a desired blood vessel can be clearly displayed. Further, since the bone tissue region of interest 196 is an area that extends in the ultrasonic scanning direction (X-axis direction), not only the bone tissue is detected, but also other living tissues with high luminance and the entire contour are detected. Therefore, the positional relationship between blood vessels can be grasped more clearly.

  Of course, according to the present embodiment, the combined two-dimensional luminance image of the blood vessel and bone tissue to be examined is displayed next to the tomographic image regarding the desired cross section, and the tomographic image at which position of the combined two-dimensional luminance image is marked. Therefore, the relationship between the two can be grasped concretely (objectively), and blood vessels can be easily analyzed without special experience. For this reason, what cannot be diagnosed from the outside and those that are difficult to diagnose even by X-ray imaging can be grasped even without special experience. Moreover, the operation is simple and can be observed easily. Moreover, there is no danger like X-rays, and since there are no legal restrictions on operation, anyone can use it easily. Furthermore, it can be manufactured at a much lower cost than a CT scanning device or the like.

  In the above-described embodiment, the two-dimensional image of the blood vessel and the bone tissue is represented by a luminance image. However, the two-dimensional image of the blood vessel and the bone tissue is displayed by a color image having a different color for each appropriate number of luminance values. Obviously, the display may be made clearer.

  It is possible to reset the closed region so that the extraction target blood vessel is included in the tubular region of interest with reference to the two-dimensional luminance image displayed in this way. Images can be displayed.

  20 to 22 are photographic diagrams showing an example in which the tomographic image and the two-dimensional luminance image as shown in FIG. 19 are actually displayed on the computer screen. 20 shows a tomographic image and two-dimensional image data of blood vessels 194a and 194b. FIG. 21 shows a tomographic image and two-dimensional image data synthesized of blood vessels 194a and 194b and bone tissues 195a, 195b and 195c. FIG. 22 shows a tomographic image, two-dimensional image data of blood vessels 194a and 194b, two-dimensional image data of bone tissues 195a, 195b and 195c, and two-dimensional images of blood vessels 194a and 194b and bone tissues 195a, 195b and 195c. This is a case where image data is displayed.

  As is clear from a comparison of FIGS. 20 and 21, in the present invention of FIG. 21, which is two-dimensional image data obtained by synthesizing blood vessels and bone tissue, it is possible to grasp the positional relationship between blood vessels very clearly. .

  All the embodiments described above are illustrative of the present invention and are not intended to be limiting, and the present invention can be implemented in other various modifications and changes. Therefore, the scope of the present invention is defined only by the claims and their equivalents.

It is a block diagram which shows roughly the structure of one Embodiment of the biological tissue multidimensional visual apparatus in this invention. It is a flowchart explaining the acquisition operation control program of ultrasonic tomographic image data. It is a figure explaining the relationship between a human body and its tomographic image. It is a figure which represents the tomographic image data of the n cross section stored in the image memory in three dimensions. It is a flowchart explaining an image display operation control program. It is a flowchart explaining the content of the low level echo cut process of FIG. It is a figure which shows the correspondence of the image in one cross-sectional example, and its ultrasonic tomographic image data. It is a flowchart explaining the content of the detection process of the skin surface position of FIG. It is a flowchart explaining the content of the process which sets the closed area | region of FIG. It is a figure explaining the vascular region of interest by a closed region, and the bone tissue region of interest by an open region. It is a figure explaining the coordinate which specifies an ellipse. It is a flowchart explaining the content of the interpolation process of the closed area | region of FIG. It is a figure which shows the relationship between the tomographic image of a specific cross section, and the oval closed region set there. It is a figure explaining the calculation content in the interpolation process of the closed area | region of FIG. It is a flowchart explaining the processing content which calculates | requires the two-dimensional image data of the blood vessel of FIG. It is a figure explaining the process which forms the two-dimensional image data of the blood vessel. It is a flowchart explaining the processing content which calculates | requires the two-dimensional image data of the bone structure | tissue of FIG. It is a figure explaining the calculation content of the average luminance value of the high-intensity part which considered the acoustic shadow of FIG. It is a figure which shows the example of a screen displayed by the image display operation control program of FIG. It is a photograph figure which shows the example which actually displayed the tomographic image and the two-dimensional luminance image on the screen of a computer. It is a photograph figure which shows the example which actually displayed the tomographic image and the two-dimensional luminance image on the screen of a computer. It is a photograph figure which shows the example which actually displayed the tomographic image and the two-dimensional luminance image on the screen of a computer.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Ultrasonic diagnostic apparatus 10a Oscillator 10b Transmission amplifier 10c Reception amplifier 10d Display part 10e Video signal output device 10f Controller 11 Probe 12 Human body 12a Test object 13 A / D converter 14 Digital computer 14a Keyboard 14b Mouse 14c CRT
14d External memory 20 Skin surface 100, 160, 193 Blood vessel region of interest 101a, 101b, 161a, 161b, 194a, 194b Blood vessel 102, 180, 196 Bone tissue region of interest 103a, 103b, 181a, 181b, 195a, 195b, 195c Bone tissue 130, 131, 133 Cross-section 130b, 131b, 133b Rectangular area 190 Screen 191 Two-dimensional luminance image 192 Tomographic image 197 Mark

Claims (13)

  Ultrasonic diagnostic means for forming ultrasonic tomographic image data composed of a plurality of pixel data arranged in the ultrasonic traveling direction and the ultrasonic scanning direction for each of a plurality of parallel sections of the living tissue, and the ultrasonic diagnosis Storage means for storing tomographic image data for each cross section formed using the means, and first region of interest setting means for setting at least one first region of interest for extracting a blood vessel for each cross section. A second region of interest setting means for setting a second region of interest for extracting a bone tissue for each cross section; and the first of the tomographic image data of each cross section stored in the storage means. First calculation means for obtaining one-dimensional image data related to blood vessels for each cross section by performing arithmetic processing on the pixel data existing in the region of interest along the ultrasonic wave traveling direction; and storing in the storage means Pixel data existing in the second region of interest among the tomographic image data of each cross section is processed along the ultrasonic traveling direction to obtain one-dimensional image data relating to bone tissue for each cross section. The second calculation means to be obtained is the same as the two-dimensional image from the obtained one-dimensional image data at the plurality of cross-sections related to blood vessels and the two-dimensional image from the obtained one-dimensional image data at the plurality of cross-sections related to bone tissue. A biological tissue multidimensional visual device comprising: display means for combining and displaying on a screen.   The biological tissue multidimensional visual device according to claim 1, wherein the first region-of-interest setting unit is a closed region setting unit that sets at least one local closed region for each cross section.   The closed region setting means sets at least one local closed region in all remaining cross sections by interpolation calculation from at least one local closed region in at least two specific cross sections arbitrarily set by the operator. The biological tissue multidimensional visual device according to claim 2, wherein the biological tissue multidimensional visual device is a setting unit that performs the setting.   The biological tissue multidimensional visual device according to claim 2 or 3, wherein the closed region setting unit is a setting unit that sets at least one local closed region having a rectangular shape or an elliptical shape.   The first calculation means obtains a luminance value of a low-luminance portion of pixel data along the ultrasonic traveling direction of the pixel data existing in the closed region, and obtains one-dimensional image data for each cross section. The biological tissue multidimensional visual device according to any one of claims 2 to 4, wherein the biological tissue multidimensional visual device is a calculation means for obtaining.   The first calculation means inverts the luminance value of the pixel data existing in the closed region, and sets the luminance value to zero when the inverted luminance value is equal to or less than a predetermined threshold, and then in the closed region. The biological tissue multidimensional visual device according to claim 5, wherein the biological tissue multidimensional visual device is a calculation means for obtaining an average luminance value of pixel data along the ultrasonic traveling direction and obtaining one-dimensional image data for each cross section.   The said 2nd region of interest setting means is a strip | belt-shaped area | region setting means which sets the strip | belt-shaped area | region along the ultrasonic scanning direction for every said cross section, The any one of Claim 1 to 6 characterized by the above-mentioned. The biological tissue multidimensional visual device described.   The second calculation means obtains the luminance value of the high-luminance portion of the pixel data along the ultrasonic wave traveling direction among the pixel data existing in the band-like region, and the one-dimensional image data for each cross section The biological tissue multidimensional visual device according to claim 7, wherein the biological tissue multidimensional visual device is a calculation means for obtaining a value.   The second calculation means obtains an average luminance value of a portion where the added value of a predetermined number of pixels along the ultrasonic wave traveling direction is maximum among the pixel data existing in the band-shaped region, The biological tissue multidimensional visual device according to claim 8, wherein the biological tissue multidimensional visual device is calculation means for obtaining one-dimensional image data of a cross section.   The biological tissue multidimensional visible according to claim 8 or 9, wherein the second calculation means is calculation means for obtaining a luminance value in consideration of an acoustic shadow and obtaining one-dimensional image data for each cross section. apparatus.   The biological tissue multidimensional visual device according to claim 10, wherein the second calculation means is set so that the luminance value is increased when an acoustic shadow is present.   The second calculation means calculates one-dimensional image data for each cross section by obtaining an average value of all pixel data along the ultrasonic wave traveling direction among the pixel data existing in the band-shaped region. The biological tissue multidimensional visual device according to claim 7, wherein the biological tissue multidimensional visual device is a calculation unit to obtain.   The display means is display means capable of displaying both the two-dimensional images and a tomographic image of a desired cross section based on tomographic image data stored in the storage means on the same screen. The biological tissue multidimensional visual device according to any one of claims 1 to 12.