Method for estimating liver volume, device for estimating liver volume and program for estimating liver volume

Abstract

To provide a method for estimating a liver volume, capable of easily and inexpensively acquiring the liver volume.SOLUTION: A method for estimating a liver volume using a plurality of cross-sectional images obtained by computed tomography or nuclear magnetic resonance imaging, the method includes the steps of: selecting, from the plurality of cross-sectional images showing the liver, a first image with a longest first length, the length in the anteroposterior direction between the ventral surface of the liver and a prescribed point on the vertebra, a second image, the cross-sectional image closest to head side, and a third image, the cross-sectional image closest to the foot side; and calculating the liver volume using the first length in the first image, a second length, the maximum length in a left-right direction between left and right abdominal walls in the first image, and a third length, the length in a vertical direction between a cross-section corresponding to the second image and a cross-section corresponding to the third image.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a method for estimating liver volume, an apparatus for estimating liver volume, and a program for estimating liver volume. [Background technology]

[0002] Polycysts of the liver is a disease in which cysts are formed in the liver, and the liver becomes enlarged as the formed cysts grow. Since polycysts of the liver have the above-mentioned characteristics, a method for evaluating the effect of treatment for polycysts of the liver from the volume of the patient's liver can be used. This method can also be used to predict the onset of complications caused by polycysts of the liver. For these reasons, it is necessary to accurately obtain the volume of the liver.

[0003] As a method for acquiring liver volume, for example, a method of manually tracing and measuring images obtained by magnetic resonance imaging (MRI) using image analysis software is known (see Non-Patent Document 1). In addition, a method of semi-automatically measuring liver volume from images obtained by MRI using software (see Non-Patent Document 2), and a method of automatically measuring liver volume from images obtained by MRI using a deep learning program (see Non-Patent Document 3) are also known. [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] Edwin M. Spithoven, et al., “Estimation of Total Kidney Volume in Autosomal Dominant Polycystic Kidney Disease”, American Journal of Kidney Diseases, Vol. 66, pp. 792-801. [Non-Patent Document 2] Yusuke Sakuhara, et al., “Initial experience with the use of tris-acryl gelatin microspheres for transcatheter arterial embolization for enlarged polycystic liver”, Clinical and Experimental Nephrology, Vol. 23, pp. 825-833. [Non-Patent Document 3] Maatje DA, et al., “Automatic Measurement of Kidney and Liver Volumes from MR Images of Patients Affected by Autosomal Dominant Polycystic Kidney Disease”, Journal of the American Society of Nephrology, Vol. 30, pp. 1514-1522. Summary of the Invention [Problem to be solved by the invention]

[0005] Methods for obtaining liver volume are known, such as those described in Non-Patent Documents 1 to 3. However, the method described in Non-Patent Document 1 requires a long time for measurement, which places a heavy burden on the person performing the measurement. In addition, the methods described in Non-Patent Documents 2 and 3 require high costs for purchasing software. Therefore, there is a demand for a method for obtaining liver volume simply and inexpensively.

[0006] An object of the present invention is to provide a method for estimating liver volume, an apparatus for estimating liver volume, and a program for estimating liver volume, which are capable of obtaining liver volume simply and inexpensively. [Means for solving the problem]

[0007] In order to achieve the above object, one aspect of the present invention relates to the following methods for estimating liver volume [1] to [7]. [1] A method for estimating liver volume using multiple transverse images obtained by computed tomography or magnetic resonance imaging, comprising: selecting, from the plurality of transverse images showing the liver, a first image having the longest first length, which is the length in the anterior-posterior direction between the ventral surface of the liver and a predetermined point on a vertebra, a second image being the most cranial transverse image, and a third image being the most pedestal transverse image; calculating a volume of the liver using the first length in the first image, a second length that is a maximum length in a left-right direction between the left and right abdominal walls in the first image, and a third length that is a length in a vertical direction between a transverse plane corresponding to the second image and a transverse plane corresponding to the third image; 16. A method for estimating liver volume, comprising: [2] The method for estimating liver volume described in [1], wherein the liver volume is calculated by the following formula (1). V=(D×W×H) / α…Equation (1) (In formula (1), V is the volume of the liver, D is the first length, W is the second length, H is the third length, and α is a number between 2.2 and 3.8.) [3] The method for estimating liver volume described in [2], wherein α is a number between 2.8 and 3.2. [4] A method for estimating liver volume described in any of [1] to [3], wherein the specified point of the vertebra is located within the lamina, within the spinous process, or at the connection between the lamina and the spinous process. [5] A method for estimating liver volume as described in [4], wherein the specified point of the vertebra is located at the connection between the lamina and the spinous process. [6] The method for estimating liver volume according to any one of [1] to [5], wherein the liver is a human liver. [7] The method for estimating liver volume described in [6], wherein the liver is the liver of a patient with multiple hepatic cysts.

[0008] Another aspect of the present invention for achieving the above object relates to an apparatus for estimating liver volume as described below in [8]. [8] A device for estimating liver volume using multiple transverse images obtained by computed tomography or magnetic resonance imaging, comprising: a selection unit that selects, from the plurality of transverse images showing the liver, a first image having the longest first length, which is a length in the anterior-posterior direction between the ventral surface of the liver and a predetermined point of a vertebra, a second image being the transverse image closest to the head, and a third image being the transverse image closest to the foot; a calculation unit that calculates the volume of the liver using the first length in the first image, a second length that is a maximum length in a left-right direction between the left and right abdominal walls in the first image, and a third length that is a length in a vertical direction between a transverse plane corresponding to the second image and a transverse plane corresponding to the third image; 13. An apparatus for estimating liver volume comprising:

[0009] Another aspect of the present invention for achieving the above object relates to a program for estimating liver volume as described below in [9]. [9] A program for estimating liver volume using multiple transverse images obtained by computed tomography or magnetic resonance imaging, comprising: On the computer, selecting, from the plurality of transverse images showing the liver, a first image having the longest first length, which is the length in the anterior-posterior direction between the ventral surface of the liver and a predetermined point on a vertebra, a second image being the most cranial transverse image, and a third image being the most pedestal transverse image; calculating a volume of the liver using the first length in the first image, a second length that is a maximum length in a left-right direction between the left and right abdominal walls in the first image, and a third length that is a length in a vertical direction between a transverse plane corresponding to the second image and a transverse plane corresponding to the third image; Execute the A program to estimate liver volume. Effect of the Invention

[0010] According to the present invention, there are provided a method for estimating liver volume, an apparatus for estimating liver volume, and a program for estimating liver volume, which are capable of determining liver volume simply and inexpensively. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a flow chart illustrating a method for estimating liver volume according to one embodiment of the present invention. [Figure 2A] FIG. 2A is an example of a first image in one embodiment of the present invention. [Figure 2B] FIG. 2B is an example of a second image in one embodiment of the present invention. [Figure 2C] FIG. 2C is an example of a third image in one embodiment of the present invention. [Diagram 3] FIG. 3 is a block diagram showing the configuration of an apparatus for estimating liver volume according to one embodiment of the present invention. [Figure 4] FIG. 4 is a block diagram showing a schematic functional configuration of a control unit in the device for estimating liver volume. [Diagram 5] FIG. 5 is a graph showing the relationship between the estimation result and the measurement result of the liver volume in an embodiment of the present invention. [Figure 6] FIG. 6 is a graph showing the relationship between liver volumes estimated (calculated) by two evaluators in an example of the present invention.

[0012] 1. Methods for estimating liver volume FIG. 1 is a flow chart illustrating a method for estimating liver volume according to one embodiment of the present invention.

[0013] As shown in Fig. 1, a method for estimating liver volume according to an embodiment of the present invention is a method for estimating liver volume using a plurality of transverse images obtained by computed tomography or nuclear magnetic resonance imaging, and includes the steps of: (1) selecting a first image, a second image, and a third image from the plurality of transverse images showing the liver (step S30); and (2) calculating the liver volume using the first and second lengths in the first image and the third length, which is the vertical length between the transverse plane corresponding to the second image and the transverse plane corresponding to the third image (step S50). In this embodiment, the method for estimating liver volume further includes the optional steps of inputting a plurality of transverse images showing the liver (step S10), measuring the first length from the plurality of transverse images (step S20), and acquiring the second length from the first image (step S40).

[0014] In this embodiment, the liver to be estimated in volume is, for example, a human liver, a monkey liver, a dog liver, a pig liver, a cow liver, etc. Among these, a human liver is preferable, and a liver of a patient with polycystic liver is more preferable.

[0015] In the above method, the liver volume can be estimated simply by selecting three transverse images (first image, second image, and third image) from multiple transverse images obtained by computed tomography or nuclear magnetic resonance imaging, and calculating the liver volume using three lengths (first length, second length, and third length) obtained from the selected three images. Therefore, the liver volume can be obtained simply and inexpensively.

[0016] It should be noted that the method for estimating liver volume described below is intended to be performed on a computer, but is not limited to this. For example, the method may be performed manually by a person using printouts of the multiple cross-sectional images.

[0017] 1-1. Step of inputting multiple cross-sectional images (step S10) In this step, a plurality of transverse images obtained by computer tomography or nuclear magnetic resonance imaging are input to a computer. For example, a plurality of transverse images of the liver may be captured by a computer tomography device or a nuclear magnetic resonance imaging device and input to a computer. A plurality of transverse images of the liver captured in advance by computer tomography or nuclear magnetic resonance imaging may be input via a storage medium or a communication line. The input transverse images may include a transverse image that does not show the liver. From the viewpoint of making it easier to select the second image 200 and the third image 300 described later, it is preferable that a transverse image that does not show the liver is included. In addition, it is preferable that the transverse image showing the liver includes all of the transverse images of the liver in the imaging range. The number of the transverse images to be input is not particularly limited.

[0018] Furthermore, the slice thickness of each transverse image is not particularly limited, but is, for example, 1 mm or more and 5 mm or less.

[0019] 1-2. Step of measuring the first length (step S20) In this step, image analysis is performed on each of a plurality of cross-sectional images showing the liver 110 obtained by computed tomography or nuclear magnetic resonance imaging, and a first length, which is the length in the anterior-posterior direction between the ventral surface 120 of the liver 110 and a predetermined point 130a of the vertebra 130, is measured. In this embodiment, the first length may be measured using a known image analysis software or the like, or the first length may be measured by manually specifying the first length. In this specification, the "anterior-posterior direction" refers to the direction connecting the ventral side and the dorsal side of the liver (dorsal-ventral direction).

[0020] Also, in this embodiment, when the method for estimating liver volume includes step S10, the transverse images used in this step are the transverse images input in step S10. When the method does not include step S10, the transverse images used in this step are printouts of the transverse images obtained, for example, by computed tomography or magnetic resonance imaging.

[0021] The vertebra 130 includes a vertebral body 131, a lamina 132, and a spinous process 133. The above-mentioned predetermined point 130a of the vertebra 130 is not particularly limited, but from the viewpoint of estimating the liver volume more accurately, it is preferable that the predetermined point 130a is located within the lamina 132, within the spinous process 133, or at the connection part 134 between the lamina 132 and the spinous process 133, and more preferable that the predetermined point 130a is located at the connection part 134 between the lamina 132 and the spinous process 133.

[0022] 1-3. Step of selecting the first image, the second image, and the third image (step S30) Fig. 2A shows an example of a first image 100, Fig. 2B shows an example of a second image 200, and Fig. 2C shows an example of a third image 300. In this specification, in Figs. 2A to 2C, the X-axis direction is the left-right direction (described later), the Y-axis direction is the front-back direction, and the Z-axis direction is the up-down direction (described later).

[0023] In this process, from a plurality of transverse images obtained by computed tomography or nuclear magnetic resonance imaging, a first image 100 having the longest first length, a second image 200 which is the most cranial transverse image among the plurality of transverse images showing the liver 110, and a third image 300 which is the most foot-side transverse image among the plurality of transverse images showing the liver 110 are selected.

[0024] The first image 100 may be the transverse image having the longest first length, which is the length in the anterior-posterior direction between the ventral surface 120 of the liver 110 and a predetermined point 130a of the vertebra 130, among the multiple transverse images. In FIG. 2A, the predetermined point 130a is a connection 134 between the lamina 132 and the spinous process 133, and the length of the arrow A is the first length.

[0025] The method of selecting the first image 100 is not particularly limited, and may be a method of manually selecting the image having the longest first length from the plurality of transverse images, or a method of using software that automatically selects the image having the longest first length from the plurality of transverse images. Also, software may be used that automatically performs both the measurement of the first length in the plurality of transverse images and the selection of the first image 100.

[0026] In this embodiment, when the method for estimating liver volume includes step S20, the first length referred to when selecting the first image 100 is the value measured in step S20. When the method for estimating liver volume does not include step S20, the first length measured by a computer (or person) different from the computer (or person) performing the above method may be referred to.

[0027] The second image 200 may be the most cranial transverse image among the multiple transverse images showing the liver 110. The method of selecting the second image 200 is not particularly limited, and may be a method of manually selecting the most cranial transverse image showing the liver 110 from the multiple transverse images, or a method of using software to automatically select the most cranial transverse image showing the liver 110 from the multiple transverse images.

[0028] Moreover, the third image 300 may be the transverse image closest to the foot among the multiple transverse images showing the liver 110. The method of selecting the third image 300 is not particularly limited, and may be a method of manually selecting the transverse image closest to the foot showing the liver 110 from the multiple transverse images, or a method of using software to automatically select the transverse image closest to the foot showing the liver 110 from the multiple transverse images.

[0029] 1-4. Step of obtaining second length (step S40) In this step, image analysis is performed on the first image 100 selected in step S30 to obtain a second length (the length of arrow B in FIG. 2A) which is the maximum length in the left-right direction between the left and right abdominal walls 140 in the first image 100. Note that the "left-right direction" is a direction perpendicular to the anterior-posterior direction in the first image 100 in FIG. 2A, but is not limited to this and does not have to be strictly perpendicular to the anterior-posterior direction.

[0030] In this embodiment, the second length may be obtained by detecting the position in the first image 100 where the length in the left and right direction between the left and right abdominal walls 140 is maximum using known image analysis software or the like, and measuring the length in the left and right direction at the position. The second length may also be obtained by manually specifying the second length and measuring the second length. Note that the second length may be obtained by measuring the length in the left and right direction between the left and right abdominal walls 140 at multiple points from the front side to the back side (from the ventral side to the dorsal side), and selecting the maximum length from among the measured lengths.

[0031] 1-5. Step of obtaining third length (step S50) In this step, a third length is obtained, which is the length in the vertical direction between the transverse plane corresponding to the second image 200 and the transverse plane corresponding to the third image 300. The third length is obtained, for example, by multiplying the thickness (slice thickness) of each transverse image showing the liver 110 by the number of transverse images between the second image 200 and the third image 300.

[0032] 1-6. Calculating liver volume (step S60) In this step, the volume of the liver is calculated using a first length (the length of arrow A in FIG. 2A) and a second length (the length of arrow B in FIG. 2A) in the first image 100, and a third length which is the vertical length between a transverse section corresponding to the second image 200 and a transverse section corresponding to the third image 300. In this specification, the "vertical direction" refers to the direction connecting the head and tail of the liver (head-to-tail direction).

[0033] In this embodiment, when the method for estimating liver volume includes step S40, the second length used in this step is the value acquired in step S40. When the method for estimating liver volume does not include step S40, the second length acquired by a computer (or person) different from the computer (or person) performing the above method may be used. Also, the third length may use the value acquired in step S50.

[0034] Although the method of calculating the liver volume using the first length, the second length, and the third length is not particularly limited, a calculation method using the following formula (1) is preferable, which can further improve the estimation accuracy of the liver volume. V=(D×W×H) / α…Equation (1)

[0035] In formula (1), V is the liver volume, D is the first length, W is the second length, H is the third length, and α is a number between 2.2 and 3.8. From the viewpoint of further improving the estimation accuracy of the liver volume, α is preferably a number between 2.8 and 3.2, and more preferably a number between 2.9 and 3.1.

[0036] In this step, it is sufficient if the liver volume can be calculated using the first length, the second length, and the third length, and the calculation method is not limited to the method according to formula (1).

[0037] 2. Device for estimating liver volume An apparatus for estimating liver volume according to this embodiment, which can be used when carrying out the above-mentioned method for estimating liver volume, will be described.

[0038] 3 is a block diagram showing the configuration of the device 1 for estimating liver volume according to this embodiment. The device 1 includes an input unit 10, a control unit 20, an operation unit 30, a display unit 40, and a storage unit 50.

[0039] The input unit 10 inputs a plurality of cross-sectional images showing the liver obtained by the above-mentioned computed tomography or nuclear magnetic resonance imaging. The input unit 10 may input image information sent from a computed tomography device or a nuclear magnetic resonance imaging device, or may input image information stored in a storage medium.

[0040] Fig. 4 is a block diagram showing a schematic functional configuration of the control unit 20. The control unit 20 has a CPU (Central Processing Unit), a RAM (Random Access Memory), etc., and executes various processes in cooperation with various programs stored in the storage unit 50 to comprehensively control the operation of the device 1. As shown in Fig. 4, the control unit 20 also has a measurement unit 21, a selection unit 22, and a calculation unit 23. The control unit 20 operates the measurement unit 21, the selection unit 22, and the calculation unit 23 in cooperation with an image processing program stored in the storage unit 50 to estimate the volume of the liver.

[0041] The measuring unit 21 performs image analysis on the multiple cross-sectional images input from the input unit 10, and measures a first length that is a length in the anterior-posterior direction between the ventral surface 120 of the liver and a predetermined point 130a of the vertebra 130. The predetermined point 130a of the vertebra 130 (including the vertebral body 131, the lamina 132, and the spinous process 133) is not particularly limited, but is preferably located within the lamina 132, within the spinous process 133, or at the connection part 134 between the lamina 132 and the spinous process 133, from the viewpoint of further improving the estimation accuracy of the liver volume, and is more preferably located at the connection part 134 between the lamina 132 and the spinous process 133.

[0042] The measuring unit 21 may perform image analysis on the first image 100 selected by the selecting unit 22, and measure the length in the left-right direction between the left and right abdominal walls 140 at multiple points from the front to the back (from the ventral side to the dorsal side). In addition, the maximum length among the measured lengths in the left-right direction may be selected as the second length.

[0043] The selection unit 22 selects, from among the multiple transverse images input by the input unit 10, the first image 100 having the longest first length measured by the measurement unit 21, the second image 200 which is the transverse image closest to the head, and the third image 300 which is the transverse image closest to the foot.

[0044] The calculation unit 23 calculates the liver volume using a first length in the first image 100, a second length which is the maximum length in the left-right direction between the left and right abdominal walls 140 in the first image 100, and a vertical length between the transverse plane corresponding to the second image 200 and the transverse plane corresponding to the third image 300. Although the method of calculating the liver volume is not particularly limited, from the viewpoint of further improving the estimation accuracy of the liver volume, a calculation method using the following formula (1) is preferable. V=(D×W×H) / α…Equation (1)

[0045] In formula (1), V is the liver volume, D is the first length, W is the second length, H is the third length, and α is a number between 2.2 and 3.8. From the viewpoint of further improving the estimation accuracy of the liver volume, α is preferably a number between 2.8 and 3.2, and more preferably a number between 2.9 and 3.1.

[0046] The operation unit 30 has, for example, a keyboard including character input keys, numeric input keys, various function keys, etc., and a pointing device such as a mouse, and outputs a press signal of a key pressed on the keyboard and an operation signal by the pointing device as input signals to the control unit 20.

[0047] The display unit 40 is configured to include a monitor such as a CRT (Cathode Ray Tube) or LCD (Liquid Crystal Display), and displays various screens according to instructions of a display signal input from the control unit 20.

[0048] The device 1 may be provided with a LAN adapter, a router, etc., and may be configured to be connected to an external device via a communication network such as a LAN.

[0049] The storage unit 50 is configured, for example, with a HDD (Hard Disk Drive), a semiconductor non-volatile memory, etc. The storage unit 50 stores various programs and various data, etc., as described above.

[0050] 3. Program to estimate liver volume A program for estimating liver volume according to the present embodiment will be described, which can be used when estimating liver volume in the above-mentioned device 1. Note that the present invention is not limited to the following embodiment.

[0051] The image processing program of this embodiment is a program for estimating liver volume using multiple transverse images obtained by computed tomography or nuclear magnetic resonance imaging, and causes a computer to execute the steps of selecting, from the multiple transverse images showing the liver, a first image having the longest first length, which is the anterior-posterior length between the ventral surface of the liver and a specified point on the vertebrae, a second image which is the cranial-most transverse image, and a third image which is the foot-most transverse image, and calculating the liver volume using the first length in the first image, a second length which is the maximum left-right length between the left and right abdominal walls in the first image, and a third length which is the vertical length between the transverse plane corresponding to the second image and the transverse plane corresponding to the third image.

[0052] The program cooperates with the control unit 20 of the device 1 to cause the measurement unit 21, the selection unit 22, and the calculation unit 23 to function and execute image processing.

[0053] (effect) In the method, device, and program for estimating liver volume according to the present embodiment, the liver volume can be estimated simply by using the first length, the second length, and the third length obtained from the first image, the second image, and the third image. Therefore, the liver volume can be estimated simply and inexpensively by the above method, device, and program. EXAMPLES

[0054] The present invention will now be described with reference to examples, which should not be construed as limiting the scope of the present invention.

[0055] <Estimation of liver volume> For the livers (before treatment) of 26 patients with multiple hepatic cysts, multiple transverse images with a slice thickness of 5 mm were obtained by computed tomography. The length between the ventral surface of the liver and the connection between the lamina and the spinous process in the multiple transverse images obtained was defined as the first length, and the first length was manually set and measured on a computer using image analysis software (SonicDICOM Media Viewer, Fujidenolo Solutions Co., Ltd.). The transverse image with the longest measured first length was selected as the first image. Among the multiple transverse images obtained, the transverse image closest to the head, in which the liver was shown, was manually selected as the second image, and the transverse image closest to the foot, in which the liver was shown, was manually selected as the third image.

[0056] Next, the maximum length between the left and right abdominal walls in the selected first image (second length) was manually specified and measured, and the third length was calculated by multiplying the slice thickness of each transverse image by the number of transverse images between the second and third images.

[0057] The liver volume was calculated using the first length, second length, and third length according to the following formula (1), where V is the liver volume, D is the first length, W is the second length, and H is the third length. V=(D×W×H) / 3…Formula (1)

[0058] The 26 patients were treated for polycystic liver disease, and the liver volumes 24 weeks after treatment were estimated using the same method as above. Furthermore, the liver volumes 144 weeks after treatment were estimated using the same method as above.

[0059] <Liver volume measurement> For the livers of the 26 patients with multiple hepatic cysts described above, the liver volumes before the treatment for multiple hepatic cysts were measured using 3D image analysis software (SYNAPSE VINCENT, Fujifilm Corporation) for the transverse images obtained by computed tomography. The liver volumes after the treatment and 144 weeks after the treatment were also measured in the same manner. The 3D image analysis software measures the area of ​​the liver in each transverse image, multiplies the measured area by the slice thickness of each transverse image, and calculates the liver volume by summing the values ​​calculated for all transverse images in which the liver is shown. Therefore, the liver volume measured by the 3D image analysis software is equivalent to the actual measurement value. Note that the 3D image analysis software is expensive software, costing more than 5 million yen.

[0060] Table 1 shows the measurement results of the first length, the second length, and the third length of the liver before treatment, as well as the estimated and measured (actual) results of the liver volume. Table 2 shows the measurement results of the first length, the second length, and the third length of the liver after 24 weeks of treatment, as well as the estimated and measured (actual) results of the liver volume. Table 3 shows the measurement results of the first length, the second length, and the third length of the liver after 144 weeks of treatment, as well as the estimated and measured (actual) results of the liver volume. In addition, FIG. 5 shows a graph showing the relationship between the estimated and measured (actual) results of the liver volume before treatment, 24 weeks after treatment, and 144 weeks after treatment.

[0061] [Table 1]

[0062] [Table 2]

[0063] [Table 3]

[0064] The intraclass coefficient (ICC(2,1)) between estimated and measured liver volumes for all patients' livers before treatment, at 24 weeks, and at 144 weeks after treatment was 0.923 (95% confidence interval: 0.862 to 0.958).

[0065] The liver volumes of the 26 patients with multiple liver cysts described above were estimated by two evaluators (before treatment, 24 weeks after treatment, and 144 weeks after treatment). The intraclass coefficient between the two evaluators for the estimated liver volumes was 0.996 (95% confidence interval: 0.993 to 0.997). Figure 6 shows the relationship between the liver volumes estimated (calculated) by the two evaluators.

[0066] From these results, it was found that the estimated liver volume was close to the measured (actual) liver volume. It was also found that the estimation (calculation) error between evaluators was low. Therefore, it was found that the liver volume can be calculated easily and inexpensively by the above-mentioned method of estimating liver volume. [Industrial Applicability]

[0067] The method for estimating liver volume according to the present invention is useful, for example, for evaluating the effectiveness of treatment for polycysts of the liver and for predicting the onset of complications due to polycysts of the liver. [Explanation of symbols]

[0068] 1. Device for estimating liver volume 10 Input section 20 Control section 21 Measurement section 22 Sorting Department 23 Calculation section 30 Control section 40 Display section 50 Storage section 100 1st image 110 Liver 120 Ventral surface 130 vertebrae 131 Vertebrae 132 Lamina 133 spinous process 134 Connection 140 Abdominal wall 200 2nd image 300 3rd image A First Length B Second Length

Claims

1. 1. A method for estimating liver volume using multiple transverse views obtained by computed tomography or magnetic resonance imaging, comprising: selecting, from the plurality of transverse images showing the liver, a first image having the longest first length, which is the length in the anterior-posterior direction between the ventral surface of the liver and a predetermined point on a vertebra, a second image being the most cranial transverse image, and a third image being the most pedestal transverse image; calculating a volume of the liver using the first length in the first image, a second length that is a maximum length in a left-right direction between the left and right abdominal walls in the first image, and a third length that is a length in a vertical direction between a transverse plane corresponding to the second image and a transverse plane corresponding to the third image; 16. A method for estimating liver volume, comprising:

2. The method for estimating liver volume according to claim 1 , wherein the liver volume is calculated by the following formula (1): V=(D×W×H) / α...Formula (1) (In formula (1), V is the volume of the liver, D is the first length, W is the second length, H is the third length, and α is a number between 2.2 and 3.8.)

3. 3. The method for estimating liver volume according to claim 2, wherein α is a number between 2.8 and 3.

2.

4. The method of claim 1 , wherein the predetermined point of the vertebra is located within a lamina, within a spinous process, or at the junction of the lamina and the spinous process.

5. The method of claim 4 , wherein the predetermined point of the vertebra is located at the junction of the lamina and the spinous process.

6. The method for estimating liver volume according to any one of claims 1 to 5, wherein the liver is a human liver.

7. The method for estimating liver volume according to claim 6 , wherein the liver is that of a patient with multiple hepatic cysts.

8. 1. An apparatus for estimating liver volume using multiple transverse images obtained by computed tomography or nuclear magnetic resonance imaging, comprising: a selection unit that selects, from the plurality of transverse images showing the liver, a first image having the longest first length, which is a length in the anterior-posterior direction between the ventral surface of the liver and a predetermined point of a vertebra, a second image being the transverse image closest to the head, and a third image being the transverse image closest to the foot; a calculation unit that calculates a volume of the liver using the first length in the first image, a second length that is a maximum length in a left-right direction between left and right abdominal walls in the first image, and a third length that is a length in a vertical direction between a transverse plane corresponding to the second image and a transverse plane corresponding to the third image; 13. An apparatus for estimating liver volume comprising:

9. 1. A program for estimating liver volume using multiple transverse images obtained by computed tomography or nuclear magnetic resonance imaging, comprising: On the computer, selecting, from the plurality of transverse images showing the liver, a first image having the longest first length, which is the length in the anterior-posterior direction between the ventral surface of the liver and a predetermined point on a vertebra, a second image being the most cranial transverse image, and a third image being the most pedestal transverse image; calculating a volume of the liver using the first length in the first image, a second length that is a maximum length in a left-right direction between the left and right abdominal walls in the first image, and a third length that is a length in a vertical direction between a transverse plane corresponding to the second image and a transverse plane corresponding to the third image; Execute the A program to estimate liver volume.

Images