JP5368615B1 - Ultrasound diagnostic system - Google Patents

Abstract

An index value representing visceral fat mass is easily and accurately obtained in a metabolic syndrome examination.
A probe is brought into contact with the surface of the abdomen, and ultrasonic waves are transmitted and received. On the tomographic image thus formed, the length a between the body surface and the abdominal aorta and the length a1 between the outer edge of the visceral fat-containing region and the abdominal aorta are measured. Separately, the waist circumference is measured. On the premise of elliptical approximation of the abdominal section, the entire abdominal area is calculated from the abdominal circumference and length a. From the total area and the ratio of the length a and the length a1, the area of the visceral fat-containing region is calculated as the area of a similar ellipse (partial area). An index value representing the visceral fat mass is calculated from the partial area and one or more individual parameter values for the subject.
[Selection] Figure 4

Description

  The present invention relates to an ultrasonic diagnostic system, and more particularly to an ultrasonic diagnostic system for measuring visceral fat.

  Ultrasound diagnostic systems are used in the medical field. An ultrasonic diagnostic system is generally configured by an ultrasonic diagnostic apparatus or a combination of an ultrasonic diagnostic apparatus and a computer. Ultrasonic diagnostic equipment forms an image based on an ultrasonic probe (probe) that transmits ultrasonic waves to a living body and receives reflected waves from within the living body, and signals received from the ultrasonic probe And an apparatus main body that performs measurement. According to ultrasonic diagnosis, the problem of exposure that occurs in X-ray diagnosis can be avoided, and a large-scale mechanism required for X-ray diagnosis is unnecessary. From such convenience, it is desired to use ultrasonic diagnosis for medical examination of metabolic syndrome (visceral fat type obesity).

  Currently, abdominal circumference measurement is generally performed in a medical checkup of metabolic syndrome. This is because a certain correlation is observed between the abdominal circumference and visceral fat mass. However, the abdominal circumference is only length information including subcutaneous fat (including muscle), and does not directly represent the amount of visceral fat in the abdominal cavity or the size of the range where it may exist. . A method has also been proposed in which a weak current is passed through the abdomen and the visceral fat mass is estimated from the electrical resistance. However, a large-scale device is required to realize such a method, and the structure in the abdomen can be fully considered. It is not a thing. According to the technique for measuring visceral fat mass using an X-ray CT apparatus, it is possible to achieve high-precision measurement. However, in order to do so, it is necessary to construct a very large-scale system. There is a problem, especially in terms of exposure.

  In the medical examination of metabolic syndrome, particularly in the group examination, it is required to measure information representing visceral fat mass easily and quickly and with high reliability. The request cannot be satisfied sufficiently.

JP 2011-101679 A JP 2011-101680 A

  Patent Documents 1 and 2 disclose a system for measuring visceral fat mass using ultrasonic diagnosis. In the system, three distances from a reference site in the visceral fat area to three points on the outer edge of the visceral fat area are calculated by abutting the probe on three positions on the abdominal surface, and the visceral fat is calculated from the three distances. The area area is estimated. Therefore, if this system is used, it is possible to obtain an index value representing the visceral fat amount relatively easily without fear of exposure. However, there is a problem that it takes time to measure because the operation of sequentially abutting the probes at three positions is required. Of the three positions, the probe needs to be inclined at two positions on the left side and the right side, and there is a problem that it is difficult to maintain the posture of the probe in some cases. Further, since the distance between the three locations is constant regardless of the body shape, there is a problem that the geometrical relationship (particularly the angular relationship) between the reference portion and the three locations varies depending on the body shape.

  An object of the present invention is to easily and accurately measure information representing visceral fat mass. Alternatively, an object of the present invention is to accurately measure information representing visceral fat mass regardless of the body shape. Alternatively, the object of the present invention is to use both the abdominal circumference generally measured conventionally in the medical examination of metabolic syndrome and the measurement result of the ultrasonic image to easily and easily express information representing visceral fat mass and It is to measure with high accuracy.

  The ultrasonic diagnostic system according to the present invention is based on a transmitter / receiver that contacts an abdomen surface of a subject and transmits / receives an ultrasonic wave, and a reception signal obtained by the ultrasonic wave transmission / reception, An image forming unit for forming an ultrasonic image representing the inside of the abdomen, and a means for measuring the ultrasonic image, wherein a reference region existing in a visceral fat-containing region in the abdomen and the transducer A measurement unit for measuring a first length from the reference site to the abdominal surface and a second length from the reference site to the outer edge of the visceral fat-containing region on a measurement path connecting the contact site; and at least Computing means for computing an index value representing visceral fat mass based on the abdominal circumference, the first length, and the second length.

  According to the above configuration, the transducer is basically brought into contact with one place on the surface of the abdomen, and ultrasonic waves are transmitted and received in this state. Thereby, an ultrasonic image is formed. In that case, it is desirable to form a tomographic image as an ultrasonic image, but other images may be formed as long as the first length and the second length can be measured. In forming a tomographic image, a beam scanning surface corresponding to the transverse section of the abdomen may be formed, or a beam scanning surface corresponding to the longitudinal section of the abdomen may be formed. Alternatively, three-dimensional measurement may be performed and a three-dimensional image or two orthogonal cross sections may be displayed. The measurement of the first length and the second length is performed based on an input of a user who visually observes an image, or is performed as an automatic image analysis. In the former case, a point (coordinate) for distance measurement can be specified by placing a marker on the screen and positioning the marker. The reference site is preferably a tissue that is present at approximately the central position in the visceral fat-containing region (visceral fat area or abdominal cavity area), and particularly preferably the abdominal aorta (lower aorta). Since the abdominal aorta is a pulsating tissue and the blood flow part is displayed with low luminance, it is relatively easy to specify the abdominal aorta for image observation. The outer edge of the visceral fat-containing region is basically the inner edge (inner membrane) of the muscle layer inside the subcutaneous fat layer, but it may be the inner edge of the subcutaneous fat layer or the like. In any case, a point on the boundary surface that can be used as a reference is specified. The abdominal circumference is measured before or after the ultrasound diagnosis. Abdominal circumference is usually measured using a measure surrounding the abdomen. A belt with an automatic measurement function may be used, or a non-contact measurement method may be used. Since the abdominal girth has been measured in the past and is a standard examination item in a health checkup, even if the abdominal girth is used, there should be no extra burden during the examination. Rather, since the information directly related to the entire abdominal area difficult to observe by ultrasonic measurement can be used, the estimation accuracy of visceral fat mass can be improved. Based on such an abdominal circumference length, the first length, and the second length, an index value representing the visceral fat amount, that is, a correlation value recognized for the visceral fat amount is calculated. The index value may be a value representing the visceral fat amount itself existing on the two-dimensional plane or in the three-dimensional space, or may be a value indicating the magnitude of the visceral fat amount.

  In the embodiment described later, the entire abdomen (the cross-sectional shape thereof) is approximated by an ellipse, the abdominal circumference is used as the circumference of the ellipse, and the short axis length of the ellipse is assumed to be the first length. In fact, the abdominal cross section has an approximately oval shape. In order to define the first length as the short axis length, it is desirable that the reference region is set approximately at the center in the abdominal section. Desirably, the visceral fat-containing region (its cross-sectional shape) is also approximated by an ellipse. Moreover, an ellipse representing the outer shape of the visceral fat-containing region is defined as an ellipsoidal similarity that approximates the entire abdomen. Thereby, the ellipse defining the partial area is defined as a similar shape based on the ellipse defining the entire area. In order to define the latter based on the former, preferably the ratio of the first length to the second length is utilized. As a result, as long as the ratio can be used, the length from the body surface to the outer edge of the visceral fat region and the length from the outer edge of the visceral fat region to the reference site may be measured. This is also nothing but the measurement of the first length and the second length.

  According to the elliptical approximation of the visceral fat-containing region, the organs and other tissues (tissue other than the visceral fat) existing in the region (that is, the abdominal cavity) may be evaluated as visceral fat. It is desirable to apply correction conditions so that non-target tissues are excluded. For example, the elliptical area may be multiplied by a coefficient smaller than 1.0. In addition, it is desirable to apply the correction condition so that the back side tissue such as the spine is excluded. For example, only a certain range in 360 degrees may be recognized as a range in which visceral fat may exist. Even if the measurement path is shifted in the left-right direction from the center of the abdominal section, or even if the reference site is shifted in the vertical direction from the center of the abdominal section, if the error can be reduced by applying correction conditions, etc., Such a shift is not a problem.

  In addition, the index value as the area value may be output as it is, or the area value is calculated at each position of the living body, the volume value is obtained as a sum of them, and it is output as the index value. It may be. Various methods are conceivable as the method of area calculation and volume calculation.

  Preferably, the calculation means converts visceral fat from a total area of the abdomen estimated based on the abdominal circumference and the first length using a ratio between the first length and the second length. A corresponding partial area is estimated, and the index value is calculated based on the partial area corresponding to the visceral fat. The abdominal circumference, the first length, and the second length are basically measured values. The area of the approximate shape (total area) of the entire abdomen can be calculated from the former two, and the approximate shape area (partial area) of the visceral fat-containing region can be calculated from the total area and the above ratio.

  Desirably, the total area of the abdomen is obtained by calculating the ellipse area from the minor axis radius of the ellipse and the circumference of the ellipse, giving the first length as the minor axis radius of the ellipse, and the circumference of the ellipse The partial area corresponding to the visceral fat is obtained by multiplying the total area by the square of the ratio of the first length and the second length. Is obtained by further applying a predetermined correction condition to the similar elliptical area obtained by the above. Each cross section of the abdomen and visceral fat-containing region can be approximated by an ellipse, and it is possible to define an ellipse that approximates the visceral fat-containing region as a similar shape of the cross-section that approximated the abdomen. And reasonable.

  Preferably, the predetermined correction condition includes a first correction condition that excludes a portion on the back side from the reference portion from the similar elliptical area, and a portion corresponding to an organ from the similar elliptical area. This is the second correction condition to be performed. The back side portion is, for example, a portion where a spine or the like exists. The part corresponding to the organ may be regarded as a constant value. Or you may consider that an organ equivalent part exists in a fixed ratio with respect to a visceral fat containing area | region (area | region assumed as the ellipse).

  Preferably, the calculation means calculates the index value using a partial area corresponding to the visceral fat and one or a plurality of personal parameter values for the subject. In order to further improve the accuracy of the calculation result, that is, the index value for each subject, it is desirable to apply correction based on personal parameter values. In that case, it is desirable to use a parameter value highly correlated with the visceral fat mass. Preferably, the one or more personal parameter values include at least one of gender, age, height, and weight. For example, BMI which is a general medical examination item may be included, which can be calculated from weight and height. In addition to the above, gender and nationality (place of birth or country of origin) may be considered. Depending on the individual parameter values, not only the coefficients but also the function itself may be switched. For example, it is possible to prepare separate calculation formulas for men and women.

  Preferably, the reference site is an abdominal aorta present in the abdomen, and the measurement path is set in a direction orthogonal to the aorta. Preferably, the measurement unit is configured to specify a position of the reference portion and an outer edge position of the visceral fat region on the ultrasonic image, and a position of the reference portion and an outer edge position of the visceral fat-containing region. And a means for measuring the first length and the second length. Although the body surface position may be input, the position is usually known in the ultrasonic diagnostic apparatus. Preferably, the means for specifying the position includes means for aligning the first marker with the reference region and aligning the second marker with the outer edge of the visceral fat-containing region on the ultrasound image. Using these markers, distance measurement is performed on the ultrasound image.

  An information processing apparatus according to the present invention is an information processing apparatus for processing an abdominal tomographic image formed by contacting a transducer on an abdominal surface of a subject and transmitting and receiving ultrasonic waves. Means for performing measurement on the top, wherein a first part from the reference part to the abdominal surface on the measurement path connecting the reference part existing in the visceral fat-containing region in the abdomen and the contact part of the transducer A measurement unit that measures a length of 1 and a second length from the reference region to an outer edge of the visceral fat-containing region, means for receiving information representing the abdominal circumference of the subject, at least the abdominal circumference, Computing means for computing an index value representing visceral fat mass based on the first length and the second length. The information processing apparatus is configured as an apparatus that processes ultrasonic image data, and is, for example, a personal computer.

  Preferably, it includes means for accepting information representing one or more personal parameter values for the subject, and the calculating means further calculates the index value based on the one or more personal parameter values. . The input of the personal parameter value can be performed by manual input, network transmission, reading of a patient card, or the like.

  According to the present invention, information representing visceral fat mass can be measured easily and accurately. Or the information showing the amount of visceral fat can be accurately measured regardless of the body shape. Alternatively, the object of the present invention is to use both the abdominal circumference generally measured conventionally in the medical examination of metabolic syndrome and the measurement result of the ultrasonic image to easily and easily express information representing visceral fat mass and Accurate measurement.

It is sectional drawing which shows the contact state of the probe to an abdominal part. It is a figure which shows the relationship between an abdominal section and a tomographic image. It is a figure which shows the other contact example of a probe. It is a schematic diagram for demonstrating an ellipse approximation model. It is a figure for demonstrating the measurement of the abdominal girth length by a measure. It is a block diagram which shows the structural example of the ultrasound diagnosing system which concerns on this invention. It is a block diagram for demonstrating the calculation of an index value. It is a figure which shows the relationship between the measured value about visceral fat, and an estimated value.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the drawings.

  FIG. 1 schematically shows a cross section of the abdomen in a living body. In FIG. 1, the situation at the time of measuring the index value representing the visceral fat mass is shown. Incidentally, the X direction is the backbone direction, the Z direction is the thickness direction of the living body, and the Y direction is the left-right direction. FIG. 1 shows a cross section when viewed from the foot side to the head side.

  In FIG. 1, the living body 10 is the abdomen, the lower side is the back, and the upper side is the abdominal surface 12. For example, the living body 10 is placed on its back on a bed. A subcutaneous fat layer 14 exists inside the living body 10. The subcutaneous fat layer 14 is a layer including skin. The muscle layer 16 exists inside thereof, and the visceral fat-containing region 20 exists inside thereof. The visceral fat-containing region 20 is originally a three-dimensional region, but is shown as a two-dimensional region extending on the YZ plane in FIG. 1 and includes a plurality of organs. In the visceral fat-containing region 20, visceral fat is present in gaps other than organs and bones.

  In FIG. 1, the code | symbol 18 represents the lumbar vertebrae, and the code | symbol 24 represents the organ. In the abdomen 10, there is an abdominal aorta (lower aorta) 22 particularly in the visceral fat-containing region 20, which is a thick artery, and its pulsation can be easily visually recognized on an ultrasound image. The abdominal aorta 22 is located substantially at the center on the cross section of the abdomen 10, and in this embodiment, it is used as a reference tissue or a reference part. The outer edge of the visceral fat-containing region 20 is the inner surface of the muscle layer 16, which is indicated by reference numeral 16A.

  When measuring the index value, the probe 36 is brought into contact with the abdominal surface 12. Specifically, the abdominal aorta 22 is located at a position 40 shifted from the navel position 38 to the left hand side of the subject by a predetermined distance (for example, 2-3 cm), that is, a position avoiding the navel having an air layer. The probe 36 is brought into contact with the position 40 directly above in a vertical posture. The probe 36 forms a two-dimensional scanning surface 42 by scanning with an ultrasonic beam. In the example shown in the figure, the scanning plane 42 forms a YZ plane, that is, corresponds to a cross section. As will be described later, it is also possible to bring the probe 36 into contact so that the scanning surface has a longitudinal section. In the illustrated example, the contact position and the contact posture of the probe 36 are adjusted so that the central axis of the scanning plane 42 just crosses the center of the abdominal aorta 22 vertically. The adjustment is usually performed manually while observing a tomographic image. If the probe 36 is pushed too far, the distance measurement value will fluctuate. Therefore, as long as the wave transmitting / receiving surface of the probe 36 is in close contact with the body surface, the probe 36 is in contact with the body surface with an appropriate contact pressure. The

  FIG. 2 shows the positional relationship between the abdomen 10 and the tomographic image 44. A tissue on the scanning plane appears in the tomographic image 44. Tissue that exists outside the scan plane is not imaged. In ultrasonic measurement, particularly ultrasonic measurement by one probe contact, it is almost difficult to image the entire abdomen 10. The same is true even if the probe contact is performed a plurality of times. In this embodiment, the abdominal circumference is separately measured, and the abdominal circumference is also used for calculating the index value. That is, information indicating the size or spread of the entire abdomen (information difficult to obtain by ultrasonic diagnosis) is actively used.

  On the tomographic image 44 displayed on the screen, the first length a and the second length a1 are measured on the center line (measurement path) connecting the center of the abdominal aorta 22 and the transmission / reception center point. . In that case, each point is designated by the user by making a marker appear on the screen and designating its position. Reference numeral 46 indicates the central level of the abdominal aorta, reference numeral 48 indicates the abdominal surface level, and reference numeral 50 indicates the muscle layer inner surface level as a boundary surface. The first length a is the distance from the abdominal surface level 48 to the abdominal aorta center level 46, and the second length a1 is the distance from the muscle layer inner surface level 50 to the abdominal aorta center level 46. In the illustrated example, the measurement path corresponds to the scanning plane center line, but the measurement path may be inclined with respect to the scanning plane center line. Various measurement techniques can be applied as long as the first length a and the second length a1 can be accurately measured.

  For example, as shown in FIG. 3, an image may be formed by positioning the probe 36 so that the scanning surface 42 has a longitudinal section. Also in this case, the distance from the abdominal surface level 48A to the abdominal aorta center level 46A can be measured as the first length a, and the second length a1 from the muscle layer inner surface level 50A to the abdominal aorta center level 46A. Can be measured. In any case, it is desirable to adjust the contact position and the contact posture of the probe 36 so that the measurement path is orthogonal to the abdominal aorta, that is, it corresponds to the short axis in the elliptical approximation.

  FIG. 4 is a schematic diagram showing the calculation principle of the index value. Reference numeral 46B indicates the center of the abdominal aorta, and reference numeral 48B indicates a contact point on the body surface. A point on the measurement path connecting them and on the inner surface of the muscle layer is indicated by reference numeral 50B. An ellipse 52 has a shape approximating the outer shape of the abdominal section. From an anatomical point of view and as a rule of thumb, such approximations have a certain validity. It is assumed that the minor axis length of the ellipse 52 is the first length a. Although the ellipse 52 may deviate from the actual abdominal outline 54, even if there is a slight deviation, the measurement accuracy is greatly affected by the application of correction conditions described later or the application of a calculation formula that takes into account various parameter values. There is nothing. In addition to ultrasonic measurement, the abdominal circumference is measured at a site crossing the navel using a measure or the like. It is also possible to measure the abdominal girth length passing through another part and to substitute it in the calculation formula as it is or after correcting it. The abdominal circumference can be regarded as the ellipse circumference c. When the first length a is the minor axis radius and b is the major axis radius, the area of the ellipse (the entire abdomen area) S0 is expressed as follows, and the ellipse circumference c is approximately as follows: Expressed (other approximations may be used).

S0 = πab (1)
c = π × (2 (a ² + b ² )) ^1/2 − (ab) ² /2.2 (2)
In the above equation (2), the abdomen is an ellipse close to a circle, so the second term is ignored and the major axis radius b is
(C ² / 2π ² -a ² ) ^1/2 (3)
The total area S0 is expressed as follows.

S0 = πa (c ² / 2π ² -a ² ) ^1/2 (4)
Next, when it is assumed that the outer shape of the abdominal cavity, ie, the visceral fat-containing region, is an ellipse 56 as a similar shape of the ellipse 52 (such an assumption also from an anatomical viewpoint, The short axis radius in the ellipse 56 can be defined as a1, and the area S1 uses the ratio of the short axis radius a to the short axis radius a1 from the overall area S0 as follows: It is possible to calculate.

S1 = (a1 / a) ² S0 (5)
However, since the spine exists on the back side of the abdominal aorta in the ellipse 56 and it is necessary to exclude that portion, the range of 120 degrees on the back side in the ellipse 56 (line 58 and line 60). Excluding the fan-shaped range sandwiched between the left and right sides, the remaining 240-degree range 61, that is, 2/3 of the entire range, becomes an effective region. In addition, since organs other than visceral fat exist in the visceral fat-containing region approximated by an ellipse, it is necessary to exclude them. Therefore, a predetermined numerical value α (for example, 10 and may be a numerical value obtained by multiplying S1 by a predetermined coefficient instead) as an exclusion amount. Considering these two correction conditions, the visceral fat area S2 is calculated as follows.

S2 = (a1 / a) ² S0 × 2 / 3−α (6)
This calculation is an estimate of the effective area where visceral fat is present in the abdomen, and the area S2 can be used as an index value, and a correction based on the personal parameter value is applied to the area S2. Then, the result value can be used as an index value. As will be described later, while using only three actually measured values of the abdominal circumference c, the first length a, and the second length a1, the measured values are applied to the elliptical approximate model of the abdominal and visceral fat-containing regions. Further, by applying the necessary correction, it is possible to obtain an index value having a high practical value, that is, a reliable value. In addition to the above three actual measurement values, other actual measurement values can be used.

  FIG. 5 conceptually shows the measurement of the abdominal circumference. The outer peripheral length of the abdomen 10 is measured by a measure 62 such as a tape measure provided with a scale. It is also possible to apply automatic measurement instead of manual measurement. The measurement of the abdominal circumference can be performed before or after the ultrasound diagnosis. Of course, the abdominal circumference may be measured simultaneously with the ultrasonic diagnosis.

  FIG. 6 is a block diagram showing the configuration of the ultrasonic diagnostic system according to this embodiment. The ultrasonic diagnostic system is configured by an ultrasonic diagnostic apparatus in the present embodiment. However, image processing and index value calculation can be executed by a computer.

  The ultrasonic diagnostic system shown in FIG. 6 is roughly composed of a main body 66 and a probe 36. The main body 66 is a main body portion of the ultrasonic diagnostic apparatus, and the probe 36 is connected to the main body 66 via a cable. The probe 36 is used in contact with the body surface. The probe 36 includes an array transducer including a plurality of vibration elements. The array transducer is a 1D array transducer. An electron beam B is formed by the array transducer, and the scanning surface 69 is configured by scanning the electron beam B in the electronic scanning direction θ. In addition, r has shown the depth direction. As an electronic scanning method, an electronic linear scanning method (including an electronic convex scanning method), an electronic sector scanning method, and the like are known. A so-called 3D probe may be used as the probe 36.

  Next, the main body 66 will be described. The transmission / reception unit 68 functions as a transmission beam former and a reception beam former. At the time of transmission, the transmission / reception unit 68 supplies a plurality of transmission signals to the probe 36 in parallel. As a result, a transmission beam is formed at the probe 36. At the time of reception, a reflected wave from the living body is received by the array transducer, and a plurality of received signals are output from the received signal to the transmitting / receiving unit 68. In the transmission / reception unit 68, a phasing addition process is executed on a plurality of reception signals, thereby electronically forming a reception beam. The reception signal after the phasing addition, that is, the beam data obtained as a result is output to the signal processing unit 70.

  The signal processing unit 70 has a known circuit such as a detection circuit or a logarithmic conversion circuit, and executes predetermined signal processing on the beam data. The beam data after the signal processing is output to the image forming unit 72. The image forming unit 72 includes a digital scan converter (DSC), that is, forms a B-mode tomographic image based on a plurality of beam data. The image data is sent to the display unit 76 via the display processing unit 74, and the tomographic image is displayed on the screen in the display unit 76.

  The measurement unit 78 is a module that performs distance measurement based on user-specified coordinates on the tomographic image. In this embodiment, the first length a between the contact point on the body surface and the center of the abdominal aorta and the point corresponding to the inner surface of the muscle layer on the measurement path connecting these two points to the center of the abdominal aorta The second length a1 is measured. In this case, a plurality of markers may be displayed simultaneously on the screen. Or you may make it designate a coordinate sequentially using a single marker. Such measurement is executed after the contact position and contact posture of the probe 36 are appropriately adjusted while viewing the tomographic screen. The measurement result obtained by the measurement unit 78 is sent to the display processing unit 74 as necessary.

  The index value calculation unit 80 is based on the first length a and the second length a1 measured by the measurement unit 78 and the abdominal girth length c passed from the control unit 84, and a plurality of individuals described later. This module calculates an index value based on a parameter value. In that case, the coefficient group stored in the coefficient table 82 is referred to, that is, the index value is calculated using a plurality of coefficient values. An index value as a calculation result, that is, a value representing the visceral fat mass is sent to the display processing unit 74, and the index value is displayed as a numerical value or the like on the display unit. In this case, various parameter values used in the process of calculating the index value may be simultaneously displayed on the screen. The calculation of the index value and the coefficient group will be described later.

  The control unit 84 performs operation control of each component shown in FIG. An input unit 86 is connected to the control unit 84. The input unit 86 is composed of a keyboard, a trackball, and the like. The input unit 86 may be a port that receives information from the network, and the input unit 86 may be a card reader or the like. In the present embodiment, the coordinates of the marker are designated by the user using the input unit 86. Further, the abdominal circumference c measured separately using the input unit 84 is input. Further, a plurality of personal parameter values are input as subject information using the input unit 86. Such information may be input via a backbone network in a medical institution.

  FIG. 7 shows a conceptual diagram of the operation of the index value calculation unit 80. A calculation formula (function) for calculating the index value exists in the index value calculation unit 80, and the numerical values given to the items of the calculation formula are shown in FIG. First, measurement values a and a1 that are measurement results are input to the index value calculation unit 80. Also, various numerical values such as height, weight, BMI, age, abdominal circumference c, and the like, which are individual parameter values, are input to the index value calculation unit 80. In this embodiment, as will be described later, when calculating the index value, the abdominal circumference c is used as a correction parameter value in addition to the calculation of the entire area. The index value calculation unit 80 is provided with a plurality of coefficient values [k1, k2,..., Kn] 92 from the coefficient table described above. Based on the numerical value set given as described above, the index value calculation unit 80 assigns them to a predetermined calculation formula, and calculates an index value 98 representing the visceral fat mass as the calculation result.

  The index value calculation unit 80 may prepare a calculation formula for each age or nationality. In that case, for example, an appropriate calculation formula is selected as indicated by reference numeral 94 according to the country (region), sex, etc. as indicated by reference numeral 96, and the index value calculation unit 80 selects the selected calculation. It is desirable that the index value is calculated using an expression.

  Next, the calculation of the index value considering the personal parameter value will be described. In order to further improve the estimation accuracy of the visceral fat mass, that is, the index value, in addition to the abdominal circumference length c, the first length a, and the second length a1 described above, personal parameter values are considered when calculating the index value. desirable. The personal parameter value referred to in this case has a correlation with the visceral fat mass, and is preferably a general personal parameter value measured in a normal health examination or the like. In the present embodiment, height, weight, BMI, and age are considered in addition to the above three actual measurement values. Specifically, the corrected visceral fat amount (area) S3 is calculated as follows. In the following, height, weight, BMI, and age are numerical values.

S3 = k1 * height + k2 * weight + k3 * BMI
+ K4 * abdominal circumference c + k5 * age + k6 * S2 (7)
In the above, S2 is calculated | required from said (6) Formula. As already described, the abdominal girth c is used in the calculation of S2 and is reused as a correction parameter value. Since MBI is obtained from height and weight, as a result, height and weight are used twice as correction parameter values. In the above, k1 to k6 are coefficients (weighting coefficients), and k1 = 1.04625, k2 = −0.66080, k3 = 6.42130, k4 = 0.09900, k5 = 1.17187, k6 from the result of the multiple regression analysis for a certain male sample population. = 0.47235 is obtained. Note that the value of k4 is small, and it can be pointed out that re-consideration of the abdominal circumference c is not necessarily required. In any case, the above calculation formulas and coefficients are merely examples.

  FIG. 8 shows the correlation between the measured values of visceral fat mass for the male sample population and the estimated visceral fat mass S3 obtained using the calculation formula (7) for the same sample population. ing. The actual measurement value is obtained from the X-ray CT image. The horizontal axis indicates actual measurement values, and the vertical axis indicates estimated values. As shown in this figure, a fairly good correlation is recognized between the two, and a correlation coefficient of 0.8766 is obtained. That is, a considerably high estimation accuracy has been confirmed. It is desirable to build a calculation formula considering gender and birthplace. Alternatively, it is desirable to prepare an individual calculation formula according to them. In that case, it is conceivable to change the configuration of the calculation formula itself, or to change the coefficient set in the calculation formula.

  As described above, according to the present embodiment, a numerical value indicating the visceral fat amount can be easily obtained. In particular, since it is only necessary to bring the probe into contact with one place on the body surface, the burden on the subject and the examiner is reduced, and the examination time can be shortened. Moreover, since not only the result of one-dimensional measurement called distance measurement but also the size of the entire abdomen can be considered as the abdominal circumference length, the estimation accuracy of visceral fat mass can be improved. In the above configuration, since a plurality of individual parameter values are further taken into account, the estimation accuracy of visceral fat mass can be further increased, and conversely, a decrease in estimation accuracy due to individual differences can be prevented.

  10 abdomen, 14 subcutaneous fat layer, 16 muscle layer, 18 lumbar vertebrae, 20 visceral fat-containing region, 22 abdominal aorta, 24 organs, 36 probe, 52 ellipse approximating abdominal contour, 56 ellipse approximating the external shape of visceral fat .

Claims (11)

A transducer that abuts the subject's abdominal surface and transmits and receives ultrasonic waves;
An image forming unit that forms an ultrasonic image representing the inside of the abdomen based on a reception signal obtained by transmitting and receiving the ultrasonic wave;
Means for measuring the ultrasonic image from the reference site on the measurement path connecting the reference site present in the visceral fat-containing region in the abdomen and the contact site of the transducer A measurement unit that measures a first length to the abdominal surface and a second length from the reference site to the outer edge of the visceral fat-containing region;
A computing means for computing an index value representing visceral fat mass based on at least the abdominal circumference, the first length and the second length;
An ultrasonic diagnostic system comprising: The system of claim 1, wherein
The calculation means is a portion corresponding to visceral fat using a ratio of the first length and the second length from the entire abdominal area estimated based on the abdominal circumference and the first length. Estimate the area,
The ultrasonic diagnostic system, wherein the index value is calculated based on a partial area corresponding to the visceral fat. The system of claim 2, wherein
The total area of the abdomen is obtained by calculating the ellipse area from the short axis radius of the ellipse and the perimeter of the ellipse, giving the first length as the short axis radius of the ellipse and the abdominal circumference as the perimeter of the ellipse Is required by giving a length,
The partial area corresponding to the visceral fat is further corrected to a similar elliptical area obtained by multiplying the total area by the square of the ratio of the first length and the second length. Is required by applying the conditions,
An ultrasonic diagnostic system characterized by that. The system of claim 3, wherein
The predetermined correction condition is such that a portion corresponding to an organ is excluded from the first correction condition and the similar elliptical area to exclude a portion on the back side from the reference region from the similar elliptical area. The second correction condition to be
An ultrasonic diagnostic system characterized by that. The system of claim 2, wherein
The calculation means calculates the index value using a partial area corresponding to the visceral fat and one or more individual parameter values for the subject.
An ultrasonic diagnostic system characterized by that. The system of claim 5, wherein
The ultrasonic diagnostic system, wherein the one or more individual parameter values include at least one of sex, age, height, and weight. The system of claim 1, wherein
The reference site is the abdominal aorta present in the abdomen,
The measurement path is set in a direction orthogonal to the abdominal aorta,
An ultrasonic diagnostic system characterized by that. The system of claim 1, wherein
The measuring unit is
Means for identifying the position of the reference region and the position of the outer edge of the visceral fat region on the ultrasound image;
Means for measuring the first length and the second length based on the position of the reference portion and the position of the outer edge of the visceral fat-containing region;
An ultrasonic diagnostic system comprising: The system of claim 8, wherein
The means for specifying the position includes means for aligning the first marker with the reference site on the ultrasound image and aligning the second marker with the outer edge of the visceral fat-containing region.
An ultrasonic diagnostic system characterized by that. In an information processing apparatus for processing an abdominal tomographic image formed by contacting a transducer on an abdomen surface of a subject and performing ultrasonic transmission / reception,
Means for performing measurement on the abdominal tomographic image, wherein the abdomen from the reference site on a measurement path connecting a reference site existing in a visceral fat-containing region in the abdomen and a contact site of the transducer A measurement unit that measures a first length to the surface and a second length from the reference site to the outer edge of the visceral fat-containing region;
Means for accepting information representing the abdominal circumference of the subject;
Calculating means for calculating an index value representing visceral fat mass based on at least the abdominal circumference, the first length and the second length;
An information processing apparatus comprising: The apparatus of claim 10.
Means for accepting information representing one or more personal parameter values for the subject,
The calculation means further calculates the index value based on the one or more personal parameter values.
An information processing apparatus characterized by that.