Plain x-ray bone densitometry apparatus and method

• US 6,064,716 A
• Filed: 03/02/1999
• Issued: 05/16/2000
• Est. Priority Date: 09/05/1997
• Status: Expired due to Fees

• Current Assignee: CyberLogic, Inc.
• Original Assignee: CyberLogic, Inc.
• Inventors: Kaufman, Jonathan J., Siffert, Robert S., Chiabrera, Alessandro
• Primary Examiner(s): Porta, David P.
• Application Number:
  US09/260,850
• Time in Patent Office: 441 Days
• Field of Search: 378/51, 378/53, 378/54, 378/56, 378/58, 378/207
• US Class Current: 378/53
• CPC Class Codes: A61B 6/482 involving multiple energy imaging
• CPC Class Codes: A61B 6/505 for diagnosis of bone
• CPC Class Codes: A61B 6/583 using calibration phantoms
• CPC Class Codes: G01N 2223/419 computed tomograph
• CPC Class Codes: G01N 23/046 using tomography, e.g. computed tomography [CT]

Abstract

Non-invasive quantitative plain radiographic evaluation of bone in a bony locale of a body is performed by subjecting the bony locale to a broadband collimated x-ray beam having energy in the range of about 20 keV to 150 keV. Alongside the bony locale is a material phantom. An energy-selective multiple-film detector cassette containing at least two films is placed under the body and material phantom to receive the transmitted x-ray beam. The films in the cassette are developed and digitally scanned to produce sets of material phantom data and sets of bone data. The data sets are then processed with a feedforward neural network whereby to generate the indicated estimate of bone status, namely, bone-mineral density. In an alternative embodiment, an independent measurement is made of the total tissue thickness, and input to the neural network to achieve higher accuracy and precision.

Claims

1. A method of non-invasively and quantitatively evaluating the status of bone tissue in a bony locale of a body, as manifested through the quantity:

bone-mineral density, using a collimated broadband x-ray beam, which method comprises the steps of;

(a) providing a multiple-material phantom wherein said phantom contains more than one material;

(b) providing a multiple-film cassette, wherein said cassette contains more than one film and wherein each of said films within said cassette receives different relative portions of the energy spectrum of said broadband x-ray beam;

(c) transmitting said collimated broadband x-ray beam through said bony locale of said body and through said multiple-material phantom, wherein said multiple-material phantom is placed alongside said bony locale of said body, and wherein said multiple-film cassette is positioned to receive said x-ray beam after transmission through said bony locale and said multiple-material phantom;

(d) obtaining bony locale image data and multiple-material phantom image data associated with each of said films contained within said multiple-film cassette; and

(e) numerically processing using a neural network said bony locale image data and said multiple-material phantom image data to evaluate said status of said bone tissue.

2. A method of non-invasively and quantitatively evaluating the status of bone tissue in a bony locale of a body, as manifested through the quantity:

bone-mineral density, using a collimated broadband x-ray beam and a phantom, which method comprises the steps of;

(a) providing a multiple-film cassette, wherein said cassette contains more than one film and wherein each of said films within said cassette receives different relative portions of the energy spectrum of said broadband x-ray beam;

(b) transmitting said collimated broadband x-ray beam through said bony locale of said body and through said phantom, wherein said phantom is placed alongside said bony locale of said body, and wherein said multiple-film cassette is positioned to receive said x-ray beam after transmission through said bony locale and said phantom;

(c) obtaining bony locale image data and phantom image data associated with each of said films contained within said multiple-film cassette; and

(d) numerically processing using a neural network said bony locale image data and said phantom image data to evaluate said status of said bone tissue.

3. A method of non-invasively and quantitatively evaluating the status of bone tissue in a bony locale of a body, as manifested through the quantity:

bone-mineral density, using a collimated broadband x-ray beam and a phantom, which method comprises the steps of;

(a) providing a multiple-film cassette, wherein said cassette contains more than one film and wherein each of said films within said cassette receives different relative portions of the energy spectrum of said broadband x-ray beam;

(b) transmitting said collimated broadband x-ray beam through said bony locale of said body and through said phantom, wherein said phantom is placed alongside said bony locale of said body, and wherein said multiple-film cassette is positioned to receive said x-ray beam after transmission through said bony locale and said phantom;

(c) obtaining bony locale image data and phantom image data associated with each of said films contained within said multiple-film cassette;

(d) determining independently a total tissue thickness associated with a region of interest in said bony locale; and

(e) numerically processing using a nonlinear optimization technique said bony locale image data and said phantom image data and said total tissue thickness to evaluate said status of said bone tissue.

4. The method according to claim 3 wherein said nonlinear optimization technique includes a neural network.

5. The method according to claim 3 wherein said region of interest includes soft tissue only.

6. The method according to claim 3 wherein said region of interest includes both soft tissue and bone tissue.

7. A method of non-invasively and quantitatively evaluating the status of bone tissue in a bony locale of a body, as manifested through the quantity:

bone-mineral density, using a collimated broadband x-ray beam and a phantom, which method comprises the steps of;

(a) providing a film cassette, wherein said cassette contains a folded film and wherein each folded portion of said folded film receives different relative portions of the energy spectrum of said broadband x-ray beam;

(b) transmitting said collimated broadband x-ray beam through said bony locale of said body and through said phantom, wherein said phantom is placed alongside said bony locale of said body, and wherein said multiple-film cassette is positioned to receive said x-ray beam after transmission through said bony locale and said phantom;

(c) obtaining bony locale image data and phantom image data associated with each of said films contained within said multiple-film cassette;

(d) determining independently a total tissue thickness associated with a region of interest in said bony locale; and

(e) numerically processing using a nonlinear optimization technique said bony locale image data and said phantom image data and said total tissue thickness to evaluate said status of said bone tissue.

8. A method of non-invasively and quantitatively evaluating the status of bone tissue in a bony locale of a body, as manifested through the quantity:

bone-mineral density, using a collimated broadband x-ray beam and a phantom, which method comprises the steps of;

(a) providing a multiple-array detector, wherein said detector contains more than one array and wherein each of said arrays within said detector receives different relative portions of the energy spectrum of said broadband x-ray beam;

(b) transmitting said collimated broadband x-ray beam through said bony locale of said body and through said phantom, wherein said phantom is placed alongside said bony locale of said body, and wherein said multiple-array detector is positioned to receive said x-ray beam after transmission through said bony locale and said phantom;

(c) obtaining bony locale image data and phantom image data associated with each of said arrays contained within said multiple-array detector; and

(d) numerically processing using a nonlinear optimization technique said bony locale image data and said phantom image data and said total tissue thickness to evaluate said status of said bone tissue.