EP0245098A2 — Method and apparatus for judging deformation of v…

Claim 1

Independent Claim 63 words

A method for judging deformation of a vertebral body, which comprises measuring a central length (a), rear brim length (c), and front brim length (d) from a profile X-ray image of a vertebral body to be judged, determining ratios of c/d, a/c and a/d, and classifying deformation of the vertebral body to be judged by using indices, c, d, c/d, a/c and a/d.

Claim 2

Independent Claim 63 words

A method for judging deformation of a vertebral body, which comprises measuring a central length (a), rear brim length (c), and front brim length (d) from a profile X-ray image of a vertebral body to be judged, determining ratios of c/d, a/c and a/d, and classifying deformation of the vertebral body to be judged by using indices, c, d, c/d, a/c and a/d.

Claim 3

Dependent Claim 95 words

A method as claimed in claim 1, wherein the classification of the deformation of the vertebral body to be judged is determined by using an average value (c) of the rear brim length (c) and an average value (d) of the front brim length (d), and standard deviations σ c and σ d of c and d respectively, which are determined from c and d measured from a plurality of the profile X-ray images being obtained from the vertebral bodies having substantially no deformation at the same portion of the vertebral body to be judged.

Claim 4

Dependent Claim 202 words

A method as claimed in claim 1, wherein the judgment of the classification of deformation of the vertebral body is carried out as follows: (i) c/d > β 1 ... wedge-shaped vertebrae (or anterior wedge fracture) (ii) c/d ≤ β 2 ... inverse wedge-shaped vertebrae (or inverse anterior wedge fracture) (iii) c < c - β 3 σ c , d < d - β 4 σ d , and β 2 < c/d < β 1 ... flat vertebrae (or compression fracture) (iv) a/c ≤ β 5 a/d ≦ β 6 and, c ≧ c - β 3 σ c and/or d≧ d - β 4 σ d ... fish vertebra (or central biconcave fracture) (v) β 2 < c/d < β 1 , c ≧ c - β 3 σ c and/or d ≧ d - β 4 σ d , and a/c > β 5 and/or a/d > 86 ... No deformation (or no fracture) wherein β 1 to β 6 are 1.25 ≦ β 1 ≦ 1.55, 0.6 ≦ β 2 ≦ 0.8, 1 ≦ β 3 ≦ 2.5, 1 ≦ β 4 ≦ 2.5, 0.65 ≦ β 5 ≦ 0.9, and 0.65 ≦ β 6 ≦ 0.9

Claim 5

Dependent Claim 51 words

A method as claimed in claim 3, wherein β 1 to β 6 are 1.33 ≦ β 1 ≦ 1.5, 0.65 ≦ β 2 ≦ 0.75, 1.25 ≦ β 3 ≦ 2.25, 1.25 ≦ β 4 ≦ 2.25, 0.7 ≦ β 5 ≦ 0.85, and 0.7 ≦ β 6 ≦ 0.85.

Claim 6

Dependent Claim 28 words

A method as claimed in claim 3, wherein β 1 is 1.4, β 2 0.7, β 3 2, β 4 1.5, β 5 0.8, and β 6 0.8.

Claim 7

Dependent Claim 75 words

A method as claimed in claim 2, wherein at least one of β 1 to β 6 are determined by a discriminant function capable of discriminating two groups with one or two variables by using two of a, b, c, and d or the ratio thereof, which are obtained by measuring at least 5 profile X-ray images in each of two types selected from four types, "wedge-shaped vertebrae", "fish vertebrae", "flat vertebrae", and "no deformation".

Claim 8

Dependent Claim 211 words

7 . A method as claimed in claim 6, wherein β 1 is z 5 obtained by the following discriminant function using the ratio c/d derived rom c and d, which are obtained by measuring at least 5 profile X-ray images in each of two types selected from "wedge-shaped vertebrae" and "no deformation": (i) When the standard deviation σ 1 of c/d of at least 5 profile X-ray images of "wedge-type vertebrae" is substantially the same as the standard deviation a 2 of c/d of at least 5 profile X-ray images of "no deformation". wherein µ 1 and µ 2 are averages of c/d relating to the profile X-ray images of "wedge-shaped vertebrae" and "no deformation", respectively, π 1 and π 2 are numbers of the X-ray images of "wedge-type vertebrae" and "no deformation", respectively, µ is an average of µ 1 and µ 2 , and c is an average of σ 1 and σ 2 ; and (ii) When σ 1 and σ 2 are substantially different, wherein µ 1 and U2 are averages of c/d relating to the profile X-ray images of "wedge - shaped vertebrae" and "no deformation", respectively, π 1 and π 2 are numbers of the X-ray images of "wedge-type vertebrae" and "no deformation", respectively.

Claim 9

Dependent Claim 43 words

A method as claimed in claim 1, wherein the measurement is carried out by a rule means, a digitizer means, or a means for automatically measuring the lengths from image treatment by memorizing the X-ray image with an X-ray image automatical input means.

Claim 10

Independent Claim 63 words

A method for judging deformation of a vertebral body, which comprises obtaining at least two indices by measuring a central length (a), vertebral body width (b), rear brim length (c), and front brim length (d) from a profile X-ray image of a vertebral body, analyzing these indices by discriminant function and classifying a deformation of the vertebral body from results of said analysis.

Claim 11

Independent Claim 63 words

A method for judging deformation of a vertebral body, which comprises obtaining at least two indices by measuring a central length (a), vertebral body width (b), rear brim length (c), and front brim length (d) from a profile X-ray image of a vertebral body, analyzing these indices by discriminant function and classifying a deformation of the vertebral body from results of said analysis.

Claim 12

Dependent Claim 71 words

A method as claimed in claim 9, wherein the discriminant function is obtained by using, at least two indices of a, b, c, and d measured from a plurality of the profile X-ray images of each of at least two types of "wedge-shaped vertebrae", "flat vertebrae", "fish vertebrae", and "no deformation", the X-ray images being obtained from the vertebral bodies at the same portion of the vertebral body to be judged.

Claim 13

Dependent Claim 67 words

A method as claimed in claim 10, wherein said discriminant function is obtained by using indices a, b, c, and d measured from at least 5 profile X-ray images in each of the four types of "wedge-shaped vertebrae", "flat vertebrae", "fish vertebrae", and "no deformation" and is capable of discriminating said four types of the vertebral body by using, as four variables, a, b, c, and d.

Claim 14

Dependent Claim 112 words

A method as claimed in claim 11, wherein said discriminant function is represent by the following formulae and the vertebral body is judged from the maximum value of z i to z 4 : wherein z l , z 2 , z 3 , and z 4 are discriminant values of "wedge-shaped vertebrae", "fish vertebrae", "flat vertebrae", and "no deformation", respectively, x 1 , x 2 , x 3 , and x 4 are variables corresponding to a central length, vertebral body width, rear brim length, and front brim length, respectively, a 10 , a 20 , a 30 , and a 40 are constants, and all to a 44 are coefficients.

Claim 15

Dependent Claim 68 words

A method as claimed in claim 10, wherein said discriminant function is derived from at least three indices of a, b, c, and d measured from at least 5 profile X-ray images in each of at least three types of "wedge-shaped vertebrae", "fish vertebrae", "flat vertebrae", and "no deformation" and the three types are capable of being judged by using as variables said at least three measured indices.

Claim 16

Dependent Claim 73 words

A method as claimed in claim 10, wherein said discriminant function is derived from two or three indices of a, b, c, and d measured from at least 5 profile X-ray images in each of two types of "wedge-shaped vertebrae" and "no deformation" and said two types of vertebral body are capable of being judged by using as variables said two or three measured values or the ratios of the two values thereof.

Claim 17

Dependent Claim 219 words

A method as claimed in claim 14, wherein said discriminant function is represented by the following formula in which the ratio (c/d) of c and d measured from at least 5 profile X-ray images in each of two types of "wedge-shaped vertebrae" and "no deformation" and the ratio (c/d) of less than z 5 obtained from the vertebral body to be judged is judged as "no deformation" and the ratio (c/d) equal to or larger than z 5 is judged as "wedge-shaped vertebrae". (i) When the standard deviation σ 1 of c/d of at least 5 profile X-ray images of "wedge-shaped vertebrae" is substantially the same as the standard deviation σ 2 of c/d of at least 5 profile X-ray images of "no deformation", wherein µ 1 and µ 2 are averages of c/d relating to the profile X-ray images of "wedge-shaped vertebrae" and "no deformation", resgectively, µ is an average of µ 1 and µ 2 and a is an average of σ 1 and σ 2 ; and (ii) when σ 1 and σ 2 are substantially different, wherein µ 1 and P2 are averages of c/d relating to the profile X-ray images of "wedge-shaped vertebrae" and "no deformation", respectively, π 1 and w2 are numbers of the X-ray images of "wedge-type vertebrae" and "no deformation", respectively.

Claim 18

Dependent Claim 55 words

A method as claimed in claim 14, wherein said discriminant function can discriminate "fish vertebrae" and "no deformation" by using, as variables, a, c, and d, or the ratios a/c and a/d obtained therefrom, which are measured from at least 5 profile X-ray images in each of the two types "fish vertebrae" and "no deformation".

Claim 19

Dependent Claim 49 words

A method as claimed in claim 14, wherein said discriminant function can discriminate "flat vertebrae" and "no deformation" by using, as variables, a, c, d or c, d, which are measured from at least 5 profile X-ray images in each of the two types "flat vertebrae" and "no deformation".

Claim 20

Dependent Claim 43 words

A method as claimed in claim 9, wherein the measurement is carried out by a rule means, a digitizer means, or a means for automatically measuring the lengths from image treatment by memorizing the X-ray image with an X-ray image automatical input means.

Claim 21

Independent Claim 125 words

An apparatus for judging deformation of a vertebral body comprising (i) an input means for inputting at least two values of a central length (a), vertebral body width (b), rear brim length (c), and front brim length (d) from a profile X-ray image of a vertebral body to be judged, (ii) an arithmetic means for operating the calculation necessary for discriminating "wedge-shaped vertebrae", "inverse wedge-shaped vertebrae", "fish vertebrae", "flat vertebrae", and "no deformation" to at least two types by using the above-mentioned input value, (iii) a means for discriminating the at least two types by using the calculation results, (iv) a means for inputting the discriminant function and/or standard necessary for the calculation and discrimination, and (v) an output means for outputting the judgment result.

Claim 22

Independent Claim 125 words

An apparatus for judging deformation of a vertebral body comprising (i) an input means for inputting at least two values of a central length (a), vertebral body width (b), rear brim length (c), and front brim length (d) from a profile X-ray image of a vertebral body to be judged, (ii) an arithmetic means for operating the calculation necessary for discriminating "wedge-shaped vertebrae", "inverse wedge-shaped vertebrae", "fish vertebrae", "flat vertebrae", and "no deformation" to at least two types by using the above-mentioned input value, (iii) a means for discriminating the at least two types by using the calculation results, (iv) a means for inputting the discriminant function and/or standard necessary for the calculation and discrimination, and (v) an output means for outputting the judgment result.

Claim 23

Dependent Claim 15 words

An apparatus as claimed in claim 19, wherein said input means is a digitizer means.

Claim 24

Dependent Claim 45 words

An apparatus as claimed in claim 19, wherein said input means is composed of an image input means from the X-ray image, a memory means for the input image, and an image treatment means for reading the at least two values from the memorized images.

Claim 25

Dependent Claim 25 words

An apparatus as claimed in claim 21, wherein said image input means is a TV camera means for receiving a light from the X-ray image.

Claim 26

Dependent Claim 26 words

An apparatus as claimed in claim 19, wherein said input means is a means for inputting values measured by a rule means from the X-ray image.

Claim 27

Dependent Claim 222 words

24'. An apparatus as claimed in claim 19, wherein said arithmetic means determines c/d, a/c, and a/d, said discriminating standard input means inputs a discriminating standard for c , d, σ c , a d , and β 1 to β 6 , and said discriminating means is based on the following standards: (i) c/d > β 1 ... "wedge-shaped vertebrae" (ii) c/d < β 2 ... "inverse wedge-shaped vertebrae" (iii) c < c - β 3 σ c , d < d - β 4 σ d , and < c/d < β 1 ... "flat vertebrae" (iv) β 2 < c/d < β 1 , a/c ≦ β 5 , a/d ≦ β 6 and, c > c - β 3 σ c and/or d > d - β 4 σ d ... "fish vertebrae" (v) β 2 < c / d < β 1 ,c ≧ c - β 3 σ c and/or d ≧ d - β 4 σ d , and a/c > β 5 and/or a/d > β 6 ... "no deformation" wherein β 1 to β 6 are 1.25 < β 1 ≦ 1.55, 0.6 ≦ β 2 ≦ 0.8, 1 < β 3 ≦ 2.5, 1 < β 4 ≦ 2.5, 0.65 ≦ β 5 ≦ 0.9, and 0.65 < β 6 ≦ 0.9

Claim 28

Dependent Claim 47 words

An apparatus as claimed in claim 19, wherein said apparatus is provided with a means for obtaining the discriminating standards from a plurality of the profile X-ray images of the vertebral bodies having substantial no deformation at the same portion of the vertebral body to be judged.

Claim 29

Dependent Claim 52 words

An apparatus as claimed in claim 19, wherein said arithmetic means is connected with the discriminating standard means for inputting the discriminant function and calculates the discriminating values by using the discriminant function, whereby the type of the vertebral body is determined according to the type corresponding to the maximum discriminating value.

Claim 30

Dependent Claim 40 words

An apparatus as claimed in claim 26, wherein said discriminant function judges the four types of the vertebral body, "wedge-shaped vertebrae", "fish vertebrae", "flat vertebrae", and "no deformation" from a one-dimensional formula containing four variables a, b, c, and d.

Claim 31

Dependent Claim 44 words

An apparatus as claimed in claim 19, wherein said arithmetic means calculates c/d and the discriminating means is connected with the discriminating standard input means, whereby the "wedge-shaped vertebrae" and the "no deformation" are judged by comparing the c/d value and the discriminating standard.

Claim 32

Dependent Claim 29 words

An apparatus as claimed in claim 19, wherein said apparatus further comprises a means for obtaining the constants and coefficients of the discriminant function and the discriminating standard values.

Method and apparatus for judging deformation of vertebral body

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