Computer program, contrast enhancement evaluation device, and contrast enhancement evaluation method

Abstract

This invention provides a computer program, a contrast-enhancing device, and a contrast-enhancing method that can objectively evaluate the contrast-enhancing properties of long medical devices. [Solution] The computer program is instructed to perform the following processes: acquire an image of a medical long-length object, calculate the brightness value of each pixel in the acquired image and the number of pixels for each brightness value, and then calculate a contrast-enhancing evaluation value of the medical long-length object based on the calculated brightness values ​​and number of pixels.

Description

Technical Field

[0001] The present invention relates to a computer program, a contrast evaluation device, and a contrast evaluation method.

Background Art

[0002] Since catheters and guidewires (GWs) are assumed to be used in an X-ray contrast environment, each is designed to have X-ray visibility (contrast) using an X-ray opaque material.

[0003] Patent Document 1 discloses a medical elongate body configured to be attachable to the tip of a catheter having a contrast member with X-ray opacity extending in the axial direction.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, since the design using an X-ray opaque material varies depending on the product (medical elongate body), the contrast often varies depending on the product. Also, the evaluation of the contrast itself often depends on the subjective evaluation by the operator (person).

[0006] The present invention has been made in view of such circumstances, and an object thereof is to provide a computer program, a contrast evaluation device, and a contrast evaluation method capable of objectively evaluating the contrast of a medical elongate body.

Means for Solving the Problems

[0007] (1) The computer program according to the present invention causes the computer to perform the following processes: acquire an image of a medical elongated body, calculate the brightness value of each pixel in the acquired image and the number of pixels for each brightness value, and calculate a contrast-enhancing evaluation value of the medical elongated body based on the calculated brightness values ​​and number of pixels.

[0008] Herein, embodiments of the present invention are as follows: (2) The computer program described in (1) above receives the setting of the evaluation range for the medical elongated body, calculates the brightness value of each pixel included in the image of the set evaluation range, and the number of pixels for each brightness value, and causes the computer to perform the following processing to calculate the contrast-enhancing evaluation value of the medical elongated body for which the evaluation range has been set.

[0009] (3) The computer program described in (1) or (2) above causes the computer to perform the following processes: remove the background brightness values ​​corresponding to the background portion included in the acquired image; calculate the brightness value of each pixel from which the background brightness values ​​have been removed, and the number of pixels for each brightness value; and calculate the contrast-enhancing evaluation value of the medical elongated body from which the background brightness values ​​have been removed.

[0010] (4) Any one of the computer programs described in (1) to (3) above is instructed to perform the following process on the computer: acquire multiple images of different medical elongated bodies, set the background brightness value corresponding to the background area included in the acquired multiple images to a common value, calculate the brightness value of each pixel included in the multiple images for which the background brightness value has been set to a common value, and the number of pixels for each brightness value, and calculate the contrast enhancement evaluation value for each of the different medical elongated bodies based on the calculated brightness value and number of pixels.

[0011] (5) Any one of the computer programs described in (1) to (4) above causes the computer to perform a process to determine the position of the medical elongated body based on the calculated contrast-enhancing evaluation value.

[0012] (6) Any one of the computer programs described in (1) to (5) above causes the computer to perform a process that outputs an image of the medical elongated body and a contrast evaluation result including a contrast evaluation value of the medical elongated body.

[0013] (7) The contrast-enhancing evaluation device according to the present invention comprises a control unit, which acquires an image of a medical elongated body, calculates the brightness value of each pixel in the acquired image and the number of pixels for each brightness value, and calculates a contrast-enhancing evaluation value of the medical elongated body based on the calculated brightness value and number of pixels.

[0014] (8) The contrast enhancement evaluation method according to the present invention acquires an image of a medical elongated body, calculates the brightness value of each pixel in the acquired image and the number of pixels for each brightness value, and calculates a contrast enhancement evaluation value of the medical elongated body based on the calculated brightness value and number of pixels. [Effects of the Invention]

[0015] According to the present invention, the contrast-enhancing properties of long medical devices can be objectively evaluated. [Brief explanation of the drawing]

[0016] [Figure 1] This figure shows an example of the configuration of the contrast enhancement evaluation device of this embodiment. [Figure 2] This figure shows an example of an image taken of a medical-grade long object. [Figure 3] This figure shows an example of a method for calculating the visibility conversion value. [Figure 4] This figure shows the first example of the calculation result for the visibility conversion value. [Figure 5] This figure shows a second example of the calculation results for the visibility conversion value. [Figure 6] This figure shows an example of the background area in an image of a medical-grade long object. [Figure 7] This figure shows an example of background removal performed by the background removal unit. [Figure 8] This figure shows the results of verifying the validity of the visibility conversion value of X-ray fluoroscopic images, where the shades of gray are represented by gradients. [Figure 9] It is a diagram showing the verification result of the validity of the area calculation of the X-ray imaging section. [Figure 10] It is a diagram showing the first example of an image of a prototype (sample) of a guide wire. [Figure 11] It is a diagram showing an example of the visibility conversion value of each sample by the contrast evaluation device. [Figure 12] It is a diagram showing an example of the ranking of contrast by visual inspection of an evaluator. [Figure 13] It is a diagram showing an example of comparison between the ranking of the visibility conversion value and the ranking range of the visual evaluator. [Figure 14] It is a diagram showing the second example of an image of a prototype (sample) of a guide wire. [Figure 15] It is a diagram showing an example of the visibility conversion value of each sample by the contrast evaluation device. [Figure 16] It is a diagram showing an example of the ranking of contrast by visual inspection of an evaluator. [Figure 17] It is a diagram showing an example of the visibility conversion value of each product of a guiding catheter by the contrast evaluation device. [Figure 18] It is a diagram showing an example of determining the position of a long medical body. [Figure 19] It is a diagram showing an example of the contrast evaluation result.

Mode for Carrying Out the Invention

[0017] Hereinafter, embodiments of the present invention will be described. FIG. 1 is a diagram showing an example of the configuration of a contrast evaluation device 50 of the present embodiment. The contrast evaluation device 50 includes a control unit 51 that controls the entire device, a communication unit 52, a memory 53, a display unit 54, an operation unit 55, a visibility conversion value calculation unit 56, a background removal unit 57, an evaluation range setting unit 58, a position determination unit 59, a storage unit 60, a recording medium reading unit 62, and the like.

[0018] The control unit 51 may be configured by incorporating a required number of CPUs (Central Processing Units), MPUs (Micro-Processing Units), GPUs (Graphics Processing Units), etc. Alternatively, the control unit 51 may be configured by combining DSPs (Digital Signal Processors), FPGAs (Field-Programmable Gate Arrays), etc.

[0019] The communication unit 52 is equipped with a communication module and has the function of communicating with external devices. The communication unit 52 can, for example, acquire images of a medical long object taken from an external device (e.g., an imaging device).

[0020] Medical elongated instruments include, for example, guiding catheters (also called "GCs"), catheters, and guidewires (also called "GWs"). A guiding catheter is a catheter used to guide devices (treatment equipment) such as guidewires, catheters, stents, and balloons to the coronary arteries, with its tip placed at the coronary artery ostium after passing through the aorta. These devices can be guided through the guiding catheter to reach the lesion.

[0021] These long medical devices are intended for use in an X-ray contrast environment, and therefore use radiopaque materials to maintain X-ray visibility (also referred to as "contrast-enhanced"). Images of these long medical devices (also referred to as "X-ray fluoroscopic images") are, by their nature, almost always represented in grayscale. Consequently, in X-ray fluoroscopic images, the RGB data for red, green, and blue stored in each pixel are equal in value, and each pixel stores a brightness value (0 to 255). In general, during catheter treatment, bright areas (white areas: brightness values ​​close to 255) in X-ray fluoroscopic images are areas that are not enhanced by contrast, while dark areas (black areas: brightness values ​​close to 0) are areas that are enhanced by contrast. Therefore, in X-ray fluoroscopic images, differences in contrast enhancement can be represented by differences in brightness values. For example, if a digitized X-ray fluoroscopic image is inverted to black and white, areas with high contrast enhancement will have low brightness values ​​close to 0 (black), and areas with low contrast enhancement will have high brightness values ​​close to 255 (white), the difference in brightness values ​​will remain the same.

[0022] The display unit 54 is composed of a liquid crystal display or an organic EL display, and provides a user interface (UI) to the user by displaying the required information. The display unit 54 can display the visibility conversion value calculated by the contrast evaluation device 50. Alternatively, an external display device may be provided instead of the display unit 54.

[0023] The operation unit 55 is, for example, a touch panel and can perform operations such as operating icons displayed on the display unit 54, moving and manipulating the cursor, and inputting text. The operation unit 55 may be composed of buttons and switches, or it may be composed of a keyboard and mouse. The operation unit 55 provides a user interface (UI) to the user by accepting user input. An external input device may be provided instead of the operation unit 55.

[0024] The storage unit 60 can be made up of semiconductor memory or a hard disk, and stores a computer program 61 (program product) and necessary information.

[0025] The computer program 61 can be read by the recording medium reading unit 62 from a recording medium (e.g., an optically readable disc storage medium such as a CD-ROM) M and stored in the storage unit 60. The computer program 61 may also be read from a recording medium such as a storage device (semiconductor memory such as an SSD (Solid State Drive)) connected by a standard for connecting to a computer (e.g., USB (Universal Serial Bus) or other standards) and stored in the storage unit 60. Alternatively, the computer program 61 may be downloaded from an external device via the communication unit 52 and stored in the storage unit 60.

[0026] The memory 53 can be composed of semiconductor memory such as SRAM (Static Random Access Memory), DRAM (Dynamic Random Access Memory), or flash memory. The computer program 61 is loaded into the memory 53, and the control unit 51 can execute the computer program 61. The control unit 51 can execute the processing defined in the computer program 61. In other words, the processing performed by the control unit 51 is also the processing performed by the computer program 61.

[0027] The visibility conversion value calculation unit 56 analyzes images of the medical elongated object acquired via the communication unit 52 and calculates the visibility conversion value (also referred to as the "contrast-enhancing evaluation value") of the medical elongated object. Details of the visibility conversion value will be described later.

[0028] The background removal unit 57 removes the background portion from the image of the acquired medical elongated object. Details of the background removal process will be described later.

[0029] The evaluation range setting unit 58 sets the range (a part of the medical elongated body) from the entire medical elongated body to be evaluated for contrast enhancement. Specifically, the evaluation range setting unit 58 acquires the evaluation range set by the user via the operation unit 55 and sets the acquired evaluation range. The visibility conversion value calculation unit 56 calculates the visibility conversion value of the medical elongated body within the evaluation range set by the evaluation range setting unit 58.

[0030] The position determination unit 59 determines the position of the medical elongated body based on the visibility conversion value calculated by the visibility conversion value calculation unit 56. Details of the position determination will be described later.

[0031] The visibility conversion value calculation unit 56, the background removal unit 57, the evaluation range setting unit 58, and the position determination unit 59 may be implemented in hardware, implemented by the processing of a computer program 61 (software), or may be implemented in both hardware and software.

[0032] The contrast enhancement evaluation device 50 may be composed of multiple devices by distributing the functions within the device.

[0033] Figure 2 shows an example of an image of a medical elongated object. Figure 2 schematically shows an image of a guidewire (GW). The elongated object in the center of the image is the guidewire.

[0034] Figure 3 shows an example of a method for calculating the visibility conversion value. Contrast enhancement (visibility by visual inspection) is determined by the radiopaqueness (color intensity) of the medical long-length material and the area of ​​the radiopaque region. Therefore, the visibility conversion value can be defined by two numerical values: the radiopaqueness and the area of ​​the radiopaque region.

[0035] As shown in Figure 3, the visibility conversion value E is given by E = K0 + K1 + K2 + ... + K N It is calculated using the formula (where N is a luminance value from 0 to 255). Here, K N is, K N = (255 - N) × M N (M N(where N is the total number of pixels). Note that a smaller brightness value (closer to 0) and a darker color indicate higher image quality. However, to ensure that a larger brightness value indicates higher image quality (better visibility), the brightness value is subtracted from 255 for convenience.

[0036] Figure 4 shows the first example of the calculation results for the visibility conversion value. In Figure 4, for convenience, the brightness values ​​of the images of the medical elongated object are set to 0, 40, and 160. The brightness value of the pixels around the image is set to 160, the brightness value of the pixels in the center of the image is set to 0, and the brightness value of the pixels between the periphery and the center of the image is set to 40. There are 36 pixels with a brightness value of 0, 28 pixels with a brightness value of 40, and 36 pixels with a brightness value of 160. Therefore, the visibility conversion value E for the medical elongated object is E = (255-0) × 36 + (255-40) × 28 + (255-160) × 36 = 18620.

[0037] Figure 5 shows a second example of the calculation results for the visibility conversion value. In Figure 5, we compare image G1 and image G2. Image G1 is the same as the image exemplified in Figure 4, and the visibility conversion value E for a medical long-length object is 18620. In image G2, the area of ​​the X-ray contrast-enhanced area (dark areas, areas with brightness values ​​close to 0) is smaller than in image G1. Specifically, there are 16 pixels with a brightness value of 0, 20 pixels with a brightness value of 40, and 64 pixels with a brightness value of 160. Therefore, the visibility conversion value E for a medical long-length object is E = (255-0) × 16 + (255-40) × 20 + (255-160) × 64 = 14190. In this way, as the area of ​​the X-ray contrast-enhanced area decreases, the visibility conversion value also decreases, and by using the visibility conversion value, the contrast enhancement (X-ray visibility) of a medical long-length object can be correctly evaluated.

[0038] As described above, the control unit 51 can acquire an image of a medical elongated body, calculate the brightness value of each pixel in the acquired image and the number of pixels for each brightness value, and calculate a contrast-enhancing evaluation value (visibility equivalent value) of the medical elongated body based on the calculated brightness values ​​and number of pixels.

[0039] This allows for objective evaluation of the contrast enhancement of medical long-length materials, even when the design using radiopaque materials differs depending on the product (medical long-length material) and the contrast enhancement varies from product to product, without relying on subjective evaluations of contrast enhancement by the operator (person).

[0040] Figure 6 shows an example of the background area in an image of a medical elongated object. In the example in Figure 6, four background areas #1 to #4 are shown around the medical elongated object. Note that each background area is shown schematically for convenience. In actual X-ray fluoroscopic images, the background color is reflected in addition to the medical elongated object. Depending on the image acquisition conditions, the background color often has a certain degree of intensity (density), and the background color differs slightly depending on the background area. By removing the background area (background color) from the visibility conversion value, it is possible to calculate an accurate visibility conversion value.

[0041] Furthermore, when calculating the visibility conversion value for multiple X-ray fluoroscopic images, by standardizing the background color of each X-ray fluoroscopic image (making the background brightness value common), the visibility conversion value for multiple X-ray fluoroscopic images can be calculated as a quantitative value.

[0042] Figure 7 shows an example of background removal by the background removal unit 57. The background removal unit 57 removes the background portion from the image of the acquired medical elongated object. Specifically, the background removal unit 57 identifies the luminance value distribution of the background area of ​​the image of the medical elongated object and removes luminance values ​​equal to or greater than the lowest luminance value of the identified distribution as the background color. The removed luminance values ​​are not used in the calculation of the visibility conversion value. Even if the medical elongated object contains luminance values ​​equivalent to the background color, areas equivalent to the background color are areas without contrast enhancement, so it can be said that this does not affect the visibility conversion value. In the example in Figure 7, the lowest luminance value is 175, and luminance values ​​of 175 or higher are removed as the background color.

[0043] As described above, the control unit 51 can remove the background brightness value corresponding to the background area included in the acquired image, calculate the brightness value of each pixel from which the background brightness value has been removed, and the number of pixels for each brightness value, and calculate the contrast enhancement evaluation value (visibility conversion value) of a medical long body based on the calculated brightness value and number of pixels. By removing the background area (background color) from the visibility conversion value, it becomes possible to calculate an accurate visibility conversion value.

[0044] Furthermore, the control unit 51 can acquire multiple images of different medical elongated bodies, set the background brightness value corresponding to the background area included in the acquired multiple images to a common value, calculate the brightness value of each pixel included in the multiple images with the common background brightness value, and the number of pixels for each brightness value, and calculate the contrast enhancement evaluation value for each of the different medical elongated bodies based on the calculated brightness value and number of pixels.

[0045] In stable environments such as those used in X-ray CT (where there are few foreign objects or noise), adjusting at least one of the tube voltage and tube current of the device so that the background color is constant (common) makes it possible to compare visibility conversion values ​​between multiple images from multiple devices. Tube voltage is the voltage applied to the X-ray tube; increasing the voltage shortens the wavelength of the X-rays. Tube current is the current flowing through the X-ray tube; increasing the current increases the amount of X-rays. By adjusting at least one of the tube voltage and tube current, it is possible to adjust how the image appears, and by adjusting them so that the background color is similar, it becomes possible to compare images taken with different devices or in different environments under the same transmission conditions. This allows for the calculation of a quantitative visibility conversion value for multiple X-ray fluoroscopic images.

[0046] Furthermore, in animal experiments where it is not possible to maintain a uniform background color for images, etc., it is possible to reproduce a consistent environment by setting conditions using the following method. That is, (1) Dilute the contrast agent with water and seal it in a tubular tube. (2) In the procedure described in (1) above, prepare 2 to 4 capillaries with different dilution concentrations. (3) Each capillary is photographed, and the shooting conditions of each imaging device are adjusted so that the brightness values ​​of the background color of each are the same.

[0047] Next, we will explain the verification results regarding the validity of the visibility conversion values ​​obtained using the contrast enhancement evaluation device 50.

[0048] Figure 8 shows the results of verifying the validity of the visibility conversion value for an X-ray fluoroscopic image where the shades are represented by a gradient. In Figure 8, image G3 is an X-ray fluoroscopic image where the shades are represented by a gradient. Image G3 was analyzed to verify whether the gradient could be appropriately quantified. Open-source ImageJ was used for the analysis. In the analysis results (3D view), the gradient area is drawn linearly, indicating that the visibility conversion value has been appropriately quantified. Thus, the visibility conversion value by the contrast evaluation device 50 can be defined by two numerical values: X-ray opacity (shade) and the area of ​​the X-ray contrast-enhanced area. As shown in the verification results in Figure 8, the validity of using X-ray opacity (shade) has been verified.

[0049] Figure 9 shows the results of verifying the validity of the area calculation for the X-ray contrast-enhanced area. Image G4 has images of small circles and large circles, with a brightness value set to 64. The ratio of the number of pixels in the small circle image to the number of pixels in the large circle image is 1:2.78 (theoretical value).

[0050] The image G4, with its defined size, is analyzed in ImageJ, and the area is calculated from the histogram. When only pixels with a brightness value of 64 are considered, the ratio of the number of pixels in the small circle image to the number of pixels in the large circle image is 1:2.81, which is a slight error from the theoretical value.

[0051] However, when analyzing the image in ImageJ, including pixels with a brightness value of 64 or higher (brightness values ​​of 70-249), the ratio of the number of pixels in the small circle image to the number of pixels in the large circle image is 1:2.78, which matches the theoretical value. This is thought to be due to anti-aliasing (a process that blends the outline of an object with the background and smoothly changes the color) during the generation of image G4. Since anti-aliasing does not occur in actual X-ray fluoroscopy images, it can be concluded that these errors do not occur.

[0052] Thus, the visibility conversion value obtained by the contrast enhancement evaluation device 50 can be defined by two numerical values: radiopaqueness (color intensity) and the area of ​​the X-ray contrast-enhanced region. However, the validity of using the area of ​​the X-ray contrast-enhanced region was verified by the verification results shown in Figure 9.

[0053] Next, we will explain the verification results of the visibility conversion value using a prototype guidewire.

[0054] Figure 10 shows the first example of an image taken of a prototype (sample) of the guidewire. In the following description, the sample numbers will be represented as #1 to #9 in the specification. Figure 10 schematically shows images of the guidewires for sample numbers #1 to #9. The evaluation range of the guidewire for calculating the visibility conversion value is set to 30 mm from the tip.

[0055] Figure 11 shows examples of visibility conversion values ​​for each sample as measured by the contrast enhancement evaluation device 50. Each sample is the same as the one illustrated in Figure 10. As shown in Figure 11, the visibility conversion values ​​for samples No. #1 to #9 are 257604, 253368, 259229, 168458, 188135, 189137, 244984, 177982, and 159870.

[0056] Figure 12 shows an example of the ranking of contrast enhancement by visual inspection by evaluators. As shown in Figure 12, the ranking of contrast enhancement (visibility) by visual inspection by evaluator A was sample No. #7, #3, #2, #1, #6, #8, #9, #5, and #4. The ranking of contrast enhancement (visibility) by visual inspection by evaluator B was sample No. #3, #2, #1, #7, #6, #8, #9, #5, and #4. The ranking of contrast enhancement (visibility) by visual inspection by evaluator C was sample No. #2, #3, #1, #7, #6, #8, #5, #9, and #4. The ranking of contrast enhancement (visibility) by visual inspection by evaluator D was sample No. #7, #2, #1, #3, #6, #8, #5, #9, and #4.

[0057] The ranking of contrast enhancement (visibility) based on the visibility conversion value obtained by the contrast enhancement evaluation device 50 is as follows, as shown in Figure 11: Sample No. #3, #1, #2, #7, #6, #5, #8, #4, and #9.

[0058] Figure 13 shows an example of comparing the ranking of the visibility conversion value with the ranking range of the visual evaluators. In Figure 13, the ranking of the visibility conversion value by the contrast enhancement evaluation device 50 is indicated by a circle. The ranking of contrast enhancement for each sample No. is illustrated in Figure 12. The range indicated by the arrows shows the range of the contrast enhancement ranking for each sample as evaluated by evaluators A to D. The ranking of contrast enhancement for each sample No. is illustrated in Figure 12.

[0059] For example, as shown in Figure 12, for sample No. 1, evaluators A, B, C, and D ranked it 4, 3, 3, and 3 respectively. Therefore, in Figure 13, the arrows indicate a contrast enhancement ranking in the range of 3 to 4. The same applies to the other sample numbers.

[0060] As shown in Figure 13, out of the nine samples, four samples (Sample No. #2, #3, #6, #7) were within the range of the visual evaluator's (operator's) ranking, and for the remaining five samples (Sample No. #1, #4, #5, #8, #9), the difference from the visual evaluator's ranking was 1.

[0061] Furthermore, for sample No. #4, which all evaluators A-D ranked 9th, the visibility conversion value measured by the contrast enhancement evaluation device 50 ranked 8th. Unlike the other guidewires, the guidewire of sample No. #4 has a tapered tip in the contrast-enhancing section. From the results shown in Figure 13, it can be inferred that for products such as guidewires that have contrast enhancement only at the tip, visual evaluators focus on the tip of the guidewire to evaluate the quality of the contrast enhancement. Therefore, the evaluation range for the contrast enhancement of the guidewire will be changed as follows, and the contrast enhancement will be evaluated again.

[0062] Figure 14 shows a second example of images taken of a prototype (sample) of the guidewire. The difference from the first example shown in Figure 10 is that in the second example, the evaluation range for contrast enhancement was changed to 20 mm from the tip. In the first example, it was 30 mm from the tip.

[0063] Figure 15 shows examples of visibility conversion values ​​for each sample as measured by the contrast enhancement evaluation device 50. Each sample is the same as the one illustrated in Figure 14. As shown in Figure 15, the visibility conversion values ​​for samples No. #1 to #9 are 168099, 165557, 168535, 96025, 110119, 134735, 154548, 107246, and 98132.

[0064] Figure 16 shows an example of the ranking of contrast enhancement by visual inspection by evaluators. As shown in Figure 16, the ranking of contrast enhancement (visibility) by visual inspection by evaluator A was sample No. #7, #3, #2, #1, #6, #8, #9, #5, and #4. The ranking of contrast enhancement (visibility) by visual inspection by evaluator B was sample No. #3, #2, #1, #7, #6, #8, #9, #5, and #4. The ranking of contrast enhancement (visibility) by visual inspection by evaluator C was sample No. #2, #3, #1, #7, #6, #8, #5, #9, and #4. The ranking of contrast enhancement (visibility) by visual inspection by evaluator D was sample No. #7, #2, #1, #3, #6, #8, #5, #9, and #4.

[0065] The ranking of contrast enhancement (visibility) based on the visibility conversion value after changing the evaluation range by the contrast enhancement evaluation device 50 is as follows, as shown in Figure 15: Sample No. #3, #1, #2, #7, #6, #5, #8, #9, and #4.

[0066] As mentioned above, for sample No. #4, which all evaluators A to D ranked 9th, the ranking in the visibility conversion value measured by the contrast enhancement evaluation device 50 was also 9th, showing consistency.

[0067] As described above, the control unit 51 can receive the setting of the evaluation range for the medical elongated body, calculate the brightness value of each pixel included in the image of the set evaluation range, and the number of pixels for each brightness value, and calculate the contrast enhancement evaluation value of the medical elongated body based on the calculated brightness values ​​and number of pixels.

[0068] Depending on the product and type of medical long-length body, the contrast-enhancing area of ​​the medical long-length body differs, and the area where the operator evaluates the contrast enhancement also differs. By accepting the setting of the evaluation range and changing the evaluation range, it is possible to calculate a visibility conversion value that can be evaluated in the same way as the contrast enhancement evaluated consistently by multiple operators, and the contrast enhancement can be objectively evaluated with high accuracy for a wide variety of medical long-length bodies.

[0069] Figure 17 shows an example of the visibility conversion values ​​for each guiding catheter product using the contrast enhancement evaluation device 50. Figure 17 shows the contrast-enhancing areas of each product P1 to P4 enclosed in rectangles. As shown in Figure 17, the visibility conversion values ​​for products P1, P2, P3, and P4 are 1618828, 1655408, 1285717, and 1890935, respectively.

[0070] Product P4 has the highest contrast enhancement. Product P3 has the lowest contrast enhancement. Products P1 and P2 also exhibit some degree of contrast enhancement.

[0071] Figure 18 shows an example of determining the position of a long medical instrument. In the example in Figure 18, it is shown how to determine whether the guiding catheter and guidewire are coaxial based on a visibility conversion value and notify the operator to provide support. As shown in Figure 18, the visibility conversion value for the guidewire (GW) is set to E1, and the visibility conversion value for the marker on the guiding catheter is set to E2. For example, E1 = 60000 and E2 = 120000. The contrast-enhanced evaluation device 50 can determine the position of the guiding catheter and guidewire on the image based on the visibility conversion value calculated from the image showing the guiding catheter and guidewire.

[0072] The position determination unit 59 can determine the position of a medical elongated object based on the visibility conversion value calculated by the visibility conversion value calculation unit 56. The positional relationship can be determined by utilizing the fact that the radiopaqueness of X-rays increases when medical elongated objects overlap. For example, under conditions where the medical elongated objects to be identified each have a certain degree of radiopaqueness (and are not completely radiopaque), when the medical elongated objects overlap, the radiopaqueness of each medical elongated object is added together, resulting in a region in the image that appears highly radiopaque (dark). By using this "dark appearance" as a criterion, it becomes possible to match the positional relationship of different medical elongated objects or devices. The position determined by the position determination unit 59 can be displayed on the display unit 54 along with the visibility conversion value. This allows the operator to determine whether the guidewire is coaxial when inserting it toward the guiding catheter.

[0073] When the guidewire is inserted toward the guiding catheter and overlaps with the guiding catheter, the visibility conversion value becomes E1 + E2. Based on this visibility conversion value, it can be determined that the guidewire has been inserted into the guiding catheter.

[0074] As described above, the control unit 51 can determine the position of the medical device based on the calculated contrast enhancement evaluation value. In this way, by using the visibility conversion value, it is possible to assist the operator in guiding guidewires, catheters, etc., through the inside of the guiding catheter to reach the lesion.

[0075] Figure 19 shows an example of contrast enhancement evaluation results. The contrast enhancement evaluation results shown in Figure 19 can be displayed, for example, on the display unit 54. As shown in Figure 19, the contrast enhancement evaluation results screen displays the image of the medical elongated object and the corresponding visibility conversion value of the medical elongated object. In addition, as shown in Figure 19, the contrast enhancement ranking of the visibility conversion value of the medical elongated object may be displayed.

[0076] As described above, the control unit 51 can output (display) images of the medical long-length body and contrast-enhancing evaluation results, including the contrast-enhancing evaluation value of the medical long-length body. This allows the operator to easily determine the objective visibility (contrast enhancement) of each of the multiple medical long-length bodies, providing information to help them decide which medical long-length body to use.

[0077] By using the visibility conversion value obtained by the contrast enhancement evaluation device 50 of this embodiment, the following effects can be expected: (1) Even when using materials with different opacity properties, it becomes possible to design a system that obtains equivalent visibility (contrast enhancement) by changing the density, thickness, etc. (2) By calculating the brightness value of the contrast agent used in the procedure, it becomes possible to determine the visibility during contrast enhancement. (3) The contrast enhancement of the catheter tip and marker can also be quantified. [Explanation of Symbols]

[0078] 50 Contrast-enhancing evaluation device 51 Control Unit 52 Communications Department 53 memory 54 Display section 55 Operation section 56 Visibility conversion value calculation unit 57 Background removal part 58 Evaluation Range Setting Section 59 Position determination section 60 Storage section 61 Computer Programs 62 Recording medium reading unit

Claims

1. Images of medical-grade long objects are captured, The brightness value of each pixel in the acquired image, and the number of pixels for each brightness value are calculated. Based on the calculated brightness value and pixel count, the contrast-enhancing evaluation value of the long medical body is calculated. A computer program that instructs a computer to perform a process.

2. The setting of the evaluation range for the aforementioned medical elongated body is accepted. The brightness value of each pixel included in the image within the set evaluation range, and the number of pixels for each brightness value are calculated. The contrast enhancement evaluation value of the long medical body for which the evaluation range has been set is calculated. A computer program according to claim 1 that causes a computer to perform a process.

3. Remove the background brightness values ​​corresponding to the background area included in the acquired image. The brightness value of each pixel from which the aforementioned background brightness value has been removed, and the number of pixels for each brightness value are calculated. The contrast-enhancing evaluation value of the medical elongated body from which the background brightness value has been removed is calculated. A computer program according to claim 1 that causes a computer to perform a process.

4. By acquiring multiple images taken of different medical elongated objects, The background brightness values ​​corresponding to the background area in multiple acquired images are set to a common value. The brightness value of each pixel included in the plurality of images, in which the background brightness value is set to a common value, and the number of pixels for each brightness value are calculated. Based on the calculated brightness value and pixel count, the contrast enhancement evaluation value for each of the different medical elongated bodies is calculated. A computer program according to any one of claims 1 to 3, which causes a computer to perform a process.

5. The position of the medical elongated body is determined based on the calculated contrast enhancement evaluation value. A computer program according to any one of claims 1 to 3, which causes a computer to perform a process.

6. The system outputs an image of the medical elongated body and a contrast-enhancing evaluation result including a contrast-enhancing evaluation value of the medical elongated body. A computer program according to any one of claims 1 to 3, which causes a computer to perform a process.

7. Equipped with a control unit, The control unit, Images of long medical objects are taken, The brightness value of each pixel in the acquired image, and the number of pixels for each brightness value are calculated. Based on the calculated brightness value and pixel count, the contrast-enhancing evaluation value of the long medical body is calculated. Contrast-enhancing evaluation device.

8. Images of medical-grade long objects are captured, The brightness value of each pixel in the acquired image, and the number of pixels for each brightness value are calculated. Based on the calculated brightness value and pixel count, the contrast-enhancing evaluation value of the long medical body is calculated. Contrast enhancement evaluation method.

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