The present invention relates to methods and devices for analyzing x-ray images. In particular, devices, methods and algorithms are provided that allow for the accurate and reliable evaluation of bone mineral density and bone structure from x-ray images.
Drawings
Claims8
A method to derive quantitative information on bone structure from an x-ray image comprising:
(a) obtaining an x-ray image;
and
(b) analyzing the image obtained in step (a) using one or more indices selected from the group consisting of Hough transform, skeleton operator, morphological operators, mean pixel intensity, variance of pixel intensity, fourier spectral analysis, fractal dimension, morphological parameter and combinations thereof, thereby deriving quantitative information on bone structure,
wherein at least one of the indices is Hough transform.
09/977,012Filed 11 Oct 2001 · us provisional application
Priority
11 Oct 2000
Published
US 2002/0114425 A122 Aug 2002
Granted
10 Feb 2004
Term ended
3 Dec 2021Estimated · howhide20 years from earliest known nonprovisional domestic filing plus recorded patent term adjustment, including 53 days of adjustment. Maintenance-fee lapses, terminal disclaimers and statutory extensions have not been checked. The continuity chain may be incomplete; this is not an enforceability determination.
Inspection of images, e.g. flaw detection: biomedical image inspection
Life of this patent
Term ended 3 Dec 2021 (estimated)
Priority11 Oct 2000
Filed11 Oct 2001
Granted10 Feb 2004
Term ended3 Dec 2021
Priority11 Oct 2000
Granted10 Feb 2004
Term ended3 Dec 2021
Priority claimedParent application 60/240,157
Application filedUS 09/977,012
Assigned to Osteonet.Comassignment of assignor's interest
PublishedUS 2002/0114425 A1
Assigned to Imaging Therapeutics, Inc.assignment of assignor's interest
GrantedUS 6,690,761 B2
Assigned to Osteonet.Com, Inc.corrective coversheet to correct the name of the assignee that was previously recorded on reel 012433, frame 0205.
Assigned to Imaging Therapeutics, Inc.corrective assignment to correct the conveying party/assignor's name on the recordation cover sheet previously recorded on reel 013434 frame 0408. assignor(s) hereby confirms the conveying party/assignor's name is osteonet.com, inc..
Assigned to Imatx, Inc.merger and change of name
Assigned to Oxford Finance LLC, AS Collateral Agentsecurity interest
Assigned to Innovatus Life Sciences Lending Fund I, LP, AS Collateral Agentsecurity interest
Assigned to Imatx, Inc.release of security interest
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Assigned to Innovatus Life Sciences Lending Fund I, LPrelease of security interest
Term endedEstimated, includes 53 days of adjustment
Assigned to Conformis, Inc., Imatx, Inc.release of security interest
Description19,126 words
Summary2,432 words
#The present invention is in the field of x-ray imaging and analysis thereof. In particular, methods and compositions for the accurate analysis of bone mineral density and/or bone structure based on x-rays are described.
#X-rays and other x-ray image analysis are important diagnostic tools, particularly for bone related conditions. Currently available techniques for the noninvasive assessment of the skeleton for the diagnosis of osteoporosis or the evaluation of an increased risk of fracture include dual x-ray absorptiometry (DXA) (Eastell et al. (1998) New Engl J. Med 338:736-746); quantitative computed tomography (QCT) (Cann (1988) Radiology 166:509-522); peripheral DXA (pDXA) (Patel et al. (1999) J Clin Densitom 2:397-401); peripheral QCT (pQCT) (Gluer et. al. (1997) Semin Nucl Med 27:229-247); x-ray image absorptiometry (RA) (Gluer et. al. (1997) Semin Nucl Med 27:229-247); and quantitative ultrasound (QUS) (Njeh et al. “Quantitative Ultrasound: Assessment of Osteoporosis and Bone Status” 1999, Martin-Dunitz, London England; U.S. Pat. No. 6,077,224, incorporated herein by reference in its entirety). (See, also, WO 9945845; WO 99/08597; and U.S. Pat. No. 6,246,745).
#DXA of the spine and hip has established itself as the most widely used method of measuring BMD. Tothill, P. and D. W. Pye, (1992) Br J Radiol 65:807-813. The fundamental principle behind DXA is the measurement of the transmission through the body of x-rays of 2 different photon energy levels. Because of the dependence of the attenuation coefficient on the atomic number and photon energy, measurement of the transmission factors at 2 energy levels enables the area densities (i.e., the mass per unit projected area) of 2 different types of tissue to be inferred. In DXA scans, these are taken to be bone mineral (hydroxyapatite) and soft tissue, respectively. However, it is widely recognized that the accuracy of DXA scans is limited by the variable composition of soft tissue. Because of its higher hydrogen content, the attenuation coefficient of fat is different from that of lean tissue. Differences in the soft tissue composition in the path of the x-ray beam through bone compared with the adjacent soft tissue reference area cause errors in the BMD measurements, according to the results of several studies. Tothill, P. and D. W. Pye, (1992) Br J Radiol, 65:807-813; Svendsen, O. L., et al., (1995)J Bone Min Res 10:868-873. Moreover, DXA systems are large and expensive, ranging in price between $75,000 and $150,000.
Brief description of the drawings14 figures
#FIG. 1 shows an example of a dental x-ray. A calibration phantom 110 is seen. Regions of interest 120 have been placed for measurement of bone mineral density or structure.
#FIG. 2 shows another example of a dental x-ray. A calibration phantom 110 is seen. Regions of interest 120 have been placed for measurement of bone mineral density or structure.
#FIG. 3 shows an example of an analysis report resulting from a measurement of mandibular or maxillary bone mineral density. A subject (X) is more than one standard deviation below the mean of age-matched controls (x-axis age, y-axis arbitrary units BMD).
Detailed description16,245 words
#Before describing the present invention in detail, it is to be understood that this invention is not limited to particular formulations or process parameters as such may, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments of the invention only, and is not intended to be limiting.
#The practice of the present invention employs, unless otherwise indicated, conventional methods of x-ray imaging and processing within the skill of the art. Such techniques are explained fully in the literature. See, e.g., X-Ray Structure Determination: A Practical Guide, 2nd Edition, editors Stout and Jensen, 1989, John Wiley & Sons, publisher; Body CT: A Practical Approach, editor Slone, 1999, McGraw-Hill publisher; X-ray Diagnosis: A Physician's Approach, editor Lam, 1998 Springer-Verlag, publisher; and Dental Radiology: Understanding the X-Ray Image, editor Laetitia Brocklebank 1997, Oxford University Press publisher.
#All publications, patents and patent applications cited herein, whether above or below, are hereby incorporated by reference in their entirety.