Methods and devices for quantitative analysis of x-ray images
View Patent ↗The present invention relates to network enabled analysis of x-ray images. Also described are devices comprising calibration phantoms; methods of using these devices; methods of formulating databases containing information regarding x-ray images; the databases themselves; and methods of manipulating the information and databases.
1. An x-ray assembly for determining bone mineral density comprising
an x-ray film cover
x-ray film and
a calibration phantom having length (L) and varying thickness (T) along the length and wherein the calibration phantom is attached to the x-ray film cover.
2. The assembly according to claim 1 , wherein the calibration phantom projects free of bone tissue.
3. The assembly of claim 1 , wherein the calibration phantom is integral to the x-ray film cover.
4. The assembly of claim 1 , wherein the x-ray assembly is a dental x-ray assembly.
5. The assembly of claim 1 , wherein the thickness of the calibration phantom varies linearly along the length.
6. The assembly of claim 1 , wherein the thickness of the calibration phantom varies non-linearly along the length.
7. A method, comprising the steps of
(a) providing x-ray film, and a calibration phantom having length (L) and varying
thickness (T) along the length, wherein the thickness of the calibration phantom varies non-linearly along the length;
(b) producing an x-ray image of an anatomical structure, wherein the x-ray image comprises the calibration phantom;
(c) providing an expected calibration curve for the non-linear calibration phantom;
(d) measuring attenuation at a multitude of points in the x-ray image of the calibration phantom; and
(e) aligning the points measured in step (d) with the expected calibration curve generated in step (c), thereby generating a density calibration curve for the image.
8. The method of claim 7 , further comprising the step of translating the calibration curve describing thickness into a curve describing calcium concentration.
9. The method of claim 8 , wherein the calibration phantom comprises aluminum and the calibration curve describes aluminum thickness.
10. The method of claim 8 , further comprising:
(a) comparing attenuation information obtained from the x-ray image of a subject's anatomical structure to the generated calibration curve; and
(b) determining bone mineral density or structure of the subject.
11. The method of claim 7 , further comprising the step of calculating the average of calibration curves to generate a reference calibration curve.
12. The method of claim 11 , further comprising:
(a) comparing attenuation information obtained from the x-ray image of a subject's anatomical structure to the generated calibration curve; and
(b) determining bone mineral density or structure of the subject.
13. The method of claim 7 , further comprising:
(a) comparing attenuation information obtained from the x-ray image of a subject's anatomical structure to the generated calibration curve; and
(b) determining bone mineral density or structure of the subject.
14. The method of claim 7 , wherein the x-ray image is a dental x-ray.
15. The method of claim 7 , wherein the calibration curve is generated in a network environment.
16. A method, comprising:
producing a set of x-ray images, wherein the x-ray images include a calibration phantom having length (L) and varying thickness (T) along the length;
measuring attenuation at a multitude of points in the x-ray images of the calibration phantom, wherein each point is at known distance from a selected part of the phantom;
generating density calibration curves that describes the relationship between measured attenuation and material thickness; and
calculating the average of the density calibration curves to generate a reference calibration curve.
17. The method of claim 16 , further comprising:
(a) comparing attenuation information obtained from the x-ray image a subject's anatomical structure to the generated calibration curve; and
(b) determining bone mineral density or structure of the subject.
18. The method of claim 16 , further comprising providing an x-ray film holder attached to the calibration phantom and x-ray film.
19. The method of claim 16 , further comprising
producing an x-ray image without the calibration phantom of an anatomical structure; and
calibrating the x-ray image without the calibration phantom using the reference calibration curve.
20. The method of claim 16 , wherein the set of x-ray images are of the same anatomical structure in different individuals.
21. A method of generating a density calibration curve, comprising the steps of
(a) generating a digital x-ray image of an anatomic structure that includes a wedge-shaped calibration phantom having length (L) and varying thickness (T) along the length;
(b) generating an expected calibration curve for the wedge-shaped calibration phantom; and
(c) measuring attenuation at a multitude of points in the x-ray image including the calibration phantom;
(d) aligning the points measured in step (c) with the expected calibration curve generated in step (b), thereby generating a calibration curve for the image.
22. The method of claim 21 , further comprising the step of translating the calibration curve describing thickness into a curve describing calcium concentration.
23. The method of claim 22 , wherein the calibration phantom comprises aluminum and the calibration curve describes aluminum thickness.
24. A kit comprising an x-ray film cover, x-ray film, a calibration phantom attached to the x-ray film cover, an x-ray imaging assembly and computer programs, wherein said computer programs analyze and assess bone mineral density.
25. A method comprising the step of analyzing an x-ray image obtained using an x-ray film cover, x-ray film, and a calibration phantom having length (L) and varying thickness (T) along the length;
comparing a bone mineral density to a reference standard;
making a diagnosis of osteoporosis if the bone mineral density is below the reference standard.
26. The method of claim 25 , further comprising administering one or more anti-resorptive agents or one or more anabolic agents.
27. A calibration phantom comprising a plurality of geometric shapes, wherein a first shape of the plurality of geometric shapes is of a first geometric type, and a second shape of the plurality of geometric shapes is of a second geometric type different from the first geometric type.
28. The calibration phantom according to claim 27 , wherein the first type is rectanguler and forms a step-wedge.
29. The calibration phantom according to claim 27 , wherein the phantom comprises stainless steel.
30. The calibration phantom according to claim 29 , wherein the stainless steel comprises 0.08% carbon, 2% manganese, 1% silicon, 0.045% phosphorus, 0.03% sulphur; 10–14% nickel, 16–18% chromium, 2–3% molybdenum and 61.845%–68.845% iron.
31. The calibration phantom of claim 27 , wherein the calibration phantom is less than 2.5 cm in length and less than 5 mm in width.
32. The calibration phantom of claim 27 , wherein each geometric shape comprises at least one material in common.
33. An x-ray assembly for determining bone mineral density comprising
an x-ray film cover;
x-ray film and
a calibration phantom having length (L) and varying thickness (T) along the length and wherein the calibration phantom is integrated into the film.
34. The assembly according to claim 33 , wherein the calibration phantom projects free of bone tissue.
35. The assembly of claim 33 , wherein the x-ray assembly is a dental x-ray assembly.
36. The assembly of claim 33 , wherein the thickness of the calibration phantom varies linearly along the length.
37. The assembly of claim 33 , wherein the thickness of the calibration phantom varies non-linearly along the length.