JPH0340612B2 - - Google Patents

Description

[Detailed description of the invention]

<Industrial Application Field> The present invention relates to a method for evaluating X-ray photographic images for determining vertebral body deformation. More specifically, the present invention relates to a method for evaluating X-ray images for determining the classification of deformation of a vertebral body, which is one of the bones forming the spinal column. To determine the presence or absence of vertebral body deformity due to osteoporosis and the classification of deformity,
This is extremely important for understanding the progress of osteoporosis and confirming the effectiveness of treatment. <Conventional technology> Conventionally, doctors have visually determined the presence or absence of deformation of the vertebral body, which is one of the bones that form the spinal column, using side X-ray images of the thoracic and lumbar vertebrae. Compared to fractures of so-called long bones such as the tibia, radius, and ulna, vertebral body deformities are difficult to diagnose because they include wedge-shaped deformities, compression fractures, and depressed fractures, and individual differences in diagnosis are inevitable. Moreover, even when trying to track changes over time to confirm the therapeutic effect, it was not always possible to accurately determine the progression of deformation because it was not quantified. In addition, the ratio (a/d) between the median length a and the anterior edge length d of the third lumbar vertebra was determined and used as an index of the degree of bone atrophy (Lumbar).
Spine Score) or an index of the degree of bone atrophy (Shigei classification severity) by looking at changes in the vertical and horizontal trabeculae of the third lumbar vertebrae. It has been reported that fractures of the vertebral body can be determined by measuring the posterior edge length c [The New
The New England Journal of Medicine,
vol306446 (February 25, 1982)], there is no known method for classifying the types of vertebral body deformities. <Problems to be Solved by the Invention> As a result of intensive research into an objective evaluation method for vertebral body deformation, the present inventors have determined that the anterior edge, posterior edge, central portion, etc. We have discovered that it is possible to objectively determine the presence or absence of vertebral deformity by accurately measuring the length of the vertebral body, determining the ratio of each part of the vertebral body, and using a criterion that combines the length and ratio of the vertebral body, Furthermore,
The type of vertebral body deformation is determined using criteria that combine the length and ratio of the vertebral body, and the progression of vertebral body deformation over time is also determined from changes in the deformation type and the length of the vertebral body. The present invention has been completed based on the discovery that this can be achieved. <Means for Solving the Problems> According to the present invention, from a lateral X-ray image of a vertebral body,
Measure the median length a, trailing edge length c, and leading edge length d, and further calculate the ratios of c/d, a/c, and a/d, and calculate these c, d, c/d, a/c, and a. /d provides a method for evaluating an X-ray photographic image for determining vertebral body deformation, which is characterized by determining the type of vertebral body deformation. Conventionally, lateral X-ray images of vertebral bodies (hereinafter referred to as ``lateral
In contrast, the method of the present invention measures the length of each part of the vertebral body and creates judgment criteria using the doctor's judgment as a reference. This is a method for objectively determining the presence or absence of vertebral body deformation and the classification of the deformation type according to the criteria. The method for evaluating X-ray photographic images of the present invention will be explained in more detail below. () First, measure the median length a, posterior edge length c, and anterior edge length d for each vertebral body from a lateral X-ray of an undeformed vertebral body, and calculate the average value of c, the average value of d, and the standard deviation. Find σ. The above measurements are the median length a, posterior edge length c, and anterior edge length d determined by the patient whose vertebral body deformity is to be determined.
This is to obtain a reference value that will be used as a judgment criterion. The undeformed vertebral body to be measured should be a vertebral body of a person whose age is usually from 50 years or older to about 75 years old, taking into account the age of the patient whose vertebral body deformity is to be determined. is preferred. It is also preferable to perform measurements separately for men and women, and it is desirable to measure approximately 50 or more vertebral bodies for each. When taking a lateral X-ray image of a vertebral body, there are a total of 17 vertebral bodies, the thoracic vertebrae from the 1st thoracic vertebrae to the 12th thoracic vertebrae, and the lumbar vertebrae from the 1st lumbar vertebrae to the 5th lumbar vertebrae, so for example, the 8th thoracic vertebrae It is advantageous to separate the images into a lateral X-ray image centered on the third lumbar vertebra and a lateral X-ray image centered on the third lumbar vertebra. In addition, in lateral X-ray images centered on the 8th thoracic vertebra, the 1st thoracic vertebrae cannot be accurately measured in most cases, and the 2nd and 3rd thoracic vertebrae are often unclear, but in these vertebral bodies, Since the frequency of deformity is not large, it is sufficient to measure from the fourth or fifth thoracic vertebrae. The central length a, the posterior edge length c, and the anterior edge length d of the vertebral body are specifically as shown in FIG. To obtain these values, use a ruler, caliper, etc. to determine the median length a,
Although the trailing edge length c and the leading edge length d may be measured, the median length a (3-
4) It is also possible to measure the trailing edge length c (5-6) and the leading edge length d (1-2) and calculate the ratios of C/d, a/c, and a/d. Alternatively, the length of each part of the vertebral body may be automatically measured by storing the degree of darkening using a television camera or the like and performing image processing. () Next, from the lateral X-ray image of the vertebral body of the patient whose vertebral body deformity is to be determined, in the same manner as in (),
For each vertebral body, the median length a, posterior edge length c, and anterior edge length d are measured, and the ratios of c/d, a/c, and a/d are calculated. These measurements, etc. can be performed in exactly the same manner as in the case () above. () Next, from a, c, d, c/d, a/c, and a/d, the vertebral body deformation can be determined, for example, as follows. That is, when (A) c/d, c, d, a/c, and a/d satisfy the following conditions, it can be determined that there is "no deformation" (type N). (a) 0.70＜c/d＜1.40 (b) At least one of c≧−2〓, d≧−1.5〓 is satisfied (c) a/c＜0.80, a/d＜0.80 The first condition (a) is the ratio c/d of the trailing edge length to the leading edge length.
must be between 0.70 and 1.40. As described later, when c/d becomes 1.40 or more, the anterior edge becomes a deformed cuneiform vertebra, and c/d becomes 0.70.
The following is actually very small, but
This is because it becomes a reverse cuneiform vertebrae with a deformed posterior edge. Next, as the second condition (b), at least one of the posterior edge length c and the anterior edge length d is the average value of the posterior edge length c and the anterior edge length d of the undeformed vertebral bodies obtained in (). When and respectively, −
Must be greater than 2σ and −1.5σ. In a typical healthy vertebral body, a, c, and d are large;
a≧-2σ, c≧-2σ, d≧-1.5σ, but the vertebral body is slightly compressed and a<-2σ
Even if c≧−2σ or d≧
If any one of the conditions of -1.5ρ is satisfied, no obvious vertebral body deformation is recognized and it can be determined that there is "no deformation". As the third condition (c), at least one of a/c and a/d must be 0.80 or more. If both a/c and a/d are 0.80 or less, that is, if the median length a is particularly small compared to the posterior edge length c and the anterior edge length d, it will be determined to be a fish vertebra as described below. be. For the above reasons, if the conditions (a), (b), and (c) above are satisfied, it can be determined that there is no change. The relationship between the conditions (a), (b), and (c) above or each condition described later and each type of vertebral body deformation described later including "no change" is shown in FIG. (B) When c/d is c/d≧1.40, it can be determined as “cuneiform vertebrae” (type). As shown in Figure 3, the cuneiform vertebra is in a state where the anterior edge is deformed and the anterior edge length d is particularly small compared to the posterior edge length c.For example, the anterior edge length is shorter than the posterior edge length. If it becomes 3/4 (c/d=
1.33), deformation of the cuneiform vertebral body is already recognized, but it may not necessarily be recognized as a clear cuneiform vertebra. On the other hand, the leading edge length is 2/3 of the trailing edge length.
(c/d=1.50), it is clearly recognized as cuneiform vertebrae, so c/d≧1.40
was used as the criteria for determining cuneiform vertebrae. In addition to the so-called cuneiform vertebrae, there are other types of cuneiform vertebrae, such as upper edge compression fractures, upper edge depression fractures, lower edge compression fractures, and lower edge depression fractures, resulting in cuneiform vertebrae and anterior edge depression. This includes deformation where the length becomes shorter, and as described later, a<-2σ, c<-
Even in vertebral bodies judged to be flat vertebrae with 2σ, d<-1.5σ, the deformation of the anterior edge is particularly marked, and c/d
If ≧1.40 is satisfied, it can also be determined as cuneiform vertebrae. (C) When c/d is c/d≦0.70, it can be determined as “reverse cuneiform vertebrae” (type). In reverse cuneiform vertebrae, the anterior edge length d is smaller than the posterior edge length c due to deformation of the anterior edge part of the cuneiform vertebrae, whereas the anterior edge length d is smaller than the posterior edge length c due to the deformation of the posterior cuneiform vertebrae. It is defined as a vertebral body whose posterior edge length c is smaller than that of the vertebral body (see Fig. 3), but in reality, such a vertebral body hardly exists. Fifth
In the lumbar vertebrae, as shown in Example 1, the posterior edge length c is smaller than the anterior edge length d, and the average value of c/d is 0.95, which is less than 1. However, the posterior edge length c is smaller than the anterior edge length. When it becomes 3/4 of d (c/d=0.75)
However, there are cases where it is not clearly recognized as a reverse cuneiform vertebrae, and therefore, if c/d≦0.70, it can be determined to be a reverse cuneiform vertebrae (type). (D) If c, d, and c/d satisfy the following conditions, it can be determined as a "flat vertebrae" (type). (a) c<-2σ (b) d<-1.5σ (c) 0.70<c/d<1.40 The first condition (a) and the second condition (b) are when the trailing edge length c and the leading edge length d are When the average value of an undeformed vertebral body is taken as and, both -2σ and -1.5σ are smaller, that is, c<-2σ and d<
−1.5σ. A flat vertebra is a vertebral body whose anterior edge, center, and posterior edge are compressed and deformed relatively uniformly (see Figure 3); that is, the anterior edge length d, the median length a, and the posterior edge c are , both are getting smaller. As shown by the average length of each part of an undeformed vertebral body in Example 1, even in an undeformed vertebral body, the median length a
is smaller than the anterior edge length d and the posterior edge length c, so the characteristic of flat vertebrae is that the anterior edge length d and the posterior edge length c are particularly small, and c<-
A vertebral body with 2σ and d<−1.5σ is determined to be a flat vertebra (type). Note that c is −2σ,
The reason why d is set to -1.5σ is because c> as shown in Example 1, so by setting such conditions, c and d become approximately equal values, satisfying the conditions for a flat vertebra. This is because it becomes like that. The second condition (c) is 0.70<c/d<
It is 1.40. a<-2σ, c<-2σ, d<
Even in the case of d-1.5σ, if the deformation of the anterior edge is significant and c/d≧1.40, it is determined to be a cuneiform vertebrae, as described above, and if the deformation of the posterior edge is significant and c/d≦0.70. This is because in some cases, it is determined that the vertebrae are inverted cuneiform. (E) “Fish vertebrae” (type) when c/d, c, d, a/c, a/d satisfy the following conditions.
It can be determined that (a) 0.70<c/d<1.40 (b) At least one of c<-2σ, d<-1.5σ is satisfied (c) a/c≦0.80 and a/d≦0.80 “Fish A "vertebral body" is a vertebral body in which a depression fracture or compression fracture has occurred in the central part, and the central length a is particularly small compared to the anterior edge length d and the posterior edge length c (see Figure 3). . Therefore, among the so-called "no deformation" vertebrae, excluding cuneiform vertebrae, flattened vertebrae, and inverted cuneiform vertebrae, the median length a is particularly small. leading edge length a,
The median length a is smaller than the trailing edge length c,
When a/c<0.90 and a/d<0.90,
A fish-like deformity is already recognized, but it may not always be clearly recognized as a fish vertebra, and a/
c<0.80 and a/d<0.80 can be used as criteria for determining fish vertebrae. In addition to the so-called fish vertebrae, there are other types of fish vertebrae, such as upper edge compression fractures, upper edge depression fractures, lower edge compression fractures, and lower edge depression fractures, resulting in fish-like, centrally It includes a deformation in which the length is shortened. The criteria for determining "no change,""cuneiformvertebrae,""reverse cuneiform vertebrae,""flatvertebrae," and "fish vertebrae" have been described above, and the relationship between these criteria is shown in FIG. In the above-mentioned judgment, as a preferable example, the c/d judgment criteria is an upper limit of 1.4 and a lower limit of 0.70.
have been selected for explanation, but these values can be arbitrarily selected from the range of 1.25 to 1.55, for example, in the case of the upper limit. It can be selected preferably from the range of 1.33 to 1.50, more preferably from 1.40 to 1.45. The lower limit can be arbitrarily selected from the range of usually 0.80 to 0.60, preferably 0.75 to 0.65. As the criterion for a/c and a/d, we chose 0.8 for "no deformity" and "fish vertebrae"; this value is
It can be arbitrarily selected from the range of usually 0.65 to 0.90, preferably 0.70 to 0.85, and more preferably 0.75 to 0.80. As the criteria for c and d, we chose -2σ and -1.5σ in the cases of "no deformity", "flat vertebrae", and "fish vertebrae", but the criteria for c are usually -1.0σ ~
It can be arbitrarily selected from the range of c-2.5σ, preferably -1.25σ to -2.25σ, particularly preferably -1.5σ to -2.0σ. Similarly, the criterion for d is usually −1.0σ to −2.5σ, preferably −1.25σ
~−2.25σ, particularly preferably −1.5σ to −2.0σ
can be arbitrarily selected from the range. <Effects of the Invention> According to the method for evaluating X-ray photographic images of the present invention, the type of vertebral body deformation can be objectively evaluated, and changes in the deformation type and progression of vertebral body deformation over time can be evaluated. can also be determined. It is also very useful for controlling the progression of bone diseases such as osteoporosis and confirming therapeutic effects. <Example> Example 1 From a lateral X-ray image of the thoracolumbar vertebrae centered on the 8th thoracic vertebrae and 3rd lumbar vertebrae of a woman aged 50 to 75, the anterior edge length d, median length a, and posterior length of each vertebral body were determined. The edge length c and the vertebral body width b were measured, and for the vertebral bodies that were determined to be "no change" by the doctor, the measured values of a, b, c, d and c/
The average value ( ) and standard deviation (α) of the calculated values of d for each vertebral body are as shown in Table 1.

【table】

[Table] Example 2 Side view of thoracolumbar vertebrae of a 70-year-old osteoporotic patient (female)
From the line image, measure the median length a, vertebral body length b, posterior edge length c, and anterior edge length d of each vertebral body, calculate c/d, a/c, and a/d, and calculate the deformation of each vertebral body. Table 2 shows the results of determining the presence or absence and type of change. Note that the determination was made based on the criteria shown in FIG. below,
The same applies to Examples 3 and 4.

[Table] Example 3 The third sample of 10 osteoporosis patients (female) aged 59 to 76 years
Measure the median length a, vertebral body width b, posterior edge length c, and anterior edge length d of the third lumbar vertebra from a lateral X-ray image centered on the lumbar vertebrae, and calculate c/d, a/c, and a/d. Table 3 shows the results of determining the presence or absence of deformation and the type of deformation.

[Table] Example 4 A 67-year-old osteoporotic patient (female). From a lateral X-ray image centered on the 8th thoracic vertebrae and 3rd lumbar vertebrae, the median length a, vertebral body width b, and rear from the 6th thoracic vertebrae to the 5th lumbar vertebrae. Measure the edge length c and leading edge length d, c/d, a/c, a/d
After calculating the presence or absence of deformation and determining the type of deformation, 6 months later, a lateral X-ray image of the same region was taken again and the presence or absence of deformation and the type of deformation were determined using the same method, and a, b, Table 4 shows the results of calculating the rates of change in c and d.

【table】

[Table] The second lumbar vertebrae changed from "no change" to type (flat vertebrae) over the course of 6 months. Although there was no obvious deformity, the anterior and posterior edges of the 7th thoracic vertebrae, and the center of the 10th thoracic vertebrae tended to deteriorate. In addition, the center of the 10th thoracic vertebrae and 3rd lumbar vertebrae have also deteriorated further. On the other hand, almost no changes were observed in the 6th, 8th, 9th, 11th, and 12th thoracic vertebrae, and the 4th and 5th lumbar vertebrae.

[Brief explanation of drawings]

Figure 1 shows a lateral X-ray image of the vertebral body, and Figure 2 shows the deformation of each vertebral body, anterior edge length d, posterior edge length c, etc., according to the method of evaluating X-ray images of the present invention. FIG. 3 shows an example of vertebral body deformation.

Claims (1)

[Claims] 1 From the lateral X-ray image of the vertebral body, measure the median length a, posterior edge length c, and anterior edge length d, and further calculate c/d, a/
Find the ratio of c and a/d, and calculate these c, d, c/
1. A method for evaluating an X-ray photographic image for determining vertebral body deformation, comprising determining the type of vertebral body deformation based on d, a/c, and a/d.