Cardiovascular risk assessments using aortic calcification information derived from x-ray measurements taken with a dual energy x-ray densitometer
View Patent ↗Methods and systems for computer assisted detection of arterial calcification, for example in the abdominal artery, by using measurements such as those conventionally taken with a dual x-ray energy bone densitometers at single energy or dual energy, and for using the calcification assessment either alone or with other information to assess and report a risk of a cardiovascular event.
1. A computer-implemented method of estimating cardiovascular risk information for a patient using aortic calcification information obtained with a dual x-ray energy range bone densitometer and generating a record of the estimated risk together with a record of bone assessment information, comprising:
obtaining dual energy range x-ray measurements of a patient's anatomy that includes a selected portion of the patient's aorta, by using a dual energy range bone densitometer;
deriving digital image information describing an image of at least the selected portion of the patient's aorta, by computer processing that uses said x-ray measurements;
producing aortic calcification information describing at least one selected calcification property of the selected portion of the aorta, by computer processing that uses the digital image information;
estimating cardiovascular risk information related to an assessment of risk of a cardiovascular event by computer processing that uses the aortic calcification information;
calculating first bone assessment information, by computer processing that uses the digital image information; and
reporting the estimated cardiovascular risk information and the calculated bone assessment information.
2. A method as in claim 1 including inputting additional information regarding clinical risk factors for the patient and using said additional information in said estimating of cardiovascular risk information.
3. A method as in claim 1 including showing an image of the patient's anatomy derived using said digital image information, together with the cardiovascular risk assessment and bone assessment information.
4. A method as in claim 1 in which the calcification information comprises a grade calculated according to a selected grading scheme.
5. A method as in claim 1 in which calcification property is at least one of length of a calcified portion of the aorta, area of the calcified portion, mineral content of the calcified portion, and mineral content per unit area of the calcified portion.
6. A method as in claim 1 in which said reporting comprises concurrently showing the cardiovascular risk information and the bone assessment information.
7. A method as in claim 1 in which said reporting comprises showing the cardiovascular risk information and the bone assessment information at different times.
8. A method as in claim 1 in which said reporting comprises showing the cardiovascular risk information and the bone assessment information at a single display or document.
9. A method as in claim 1 in which said reporting comprises showing the cardiovascular risk information and the bone assessment information at separate display screens or documents.
10. A method as in claim 1 in which the producing comprises scaling aortic calcification information to patient's vertebral size information.
11. A method as in claim 1 in which the obtaining comprises obtaining the x-ray measurements from a lateral view of the patient.
12. A method as in claim 11 the deriving comprises processing the lateral view measurements, and further including obtaining dual energy range AP x-ray measurements from an AP view of the patient and computer processing the AP measurements to derive and report second bone assessment results that include indications of BMD and/or BMC.
13. A method as in claim 1 in which the selected portion of the aorta comprises a selected portion of the abdominal aorta.
14. A method as in claim 1 in which the selected portion of the aorta comprises a selected portion of the thoracic aorta.
15. A computer-implemented method comprising:
using a processor to perform steps comprising:
obtaining dual energy range x-ray measurements of a patient's anatomy that includes a selected portion of the patient's aorta, by using a dual x-ray energy range bone densitometer system;
using the x-ray measurements to derive digital image information describing an image of at least the selected portion of the patient's aorta;
producing aortic calcification information describing at least one selected calcification property of the selected portion of the aorta, by computer processing that uses the digital image information;
estimating cardiovascular risk information related to an assessment of risk of a cardiovascular event by computer processing using the aortic calcification information; and
reporting the calculated cardiovascular risk information.
16. A method as in claim 15 in which the digital image information describes values of image pixels, and the producing of aortic calcification information comprises applying at least one selected computer search algorithm to the digital image information to identify pixel groupings that meet selected pixel value characteristics.
17. A method as in claim 16 including displaying an image of the patient's anatomy, including an image of the selected portion of the aorta, derived from said digital image information, and manually marking a calcified portion of the aorta visible in the image, wherein the producing of aortic calcification information comprises using information regarding said marking in the course of computer processing the image information.
18. A method as in claim 15 including displaying an image of the patient's anatomy, including an image of the selected portion of the aorta, derived from said digital image information, and manually marking a calcified portion of the aorta visible in the image, wherein the producing of aortic calcification information comprises using information regarding said marking in the course of computer processing the image information.
19. A method as in claim 15 in which the producing of aortic calcification information comprises treating as calcified a composite of non-contiguous parts of the aorta that meet selected criteria.
20. A method as in claim 15 including inputting additional information regarding clinical risk factors for the patient and using said additional information in said estimating of cardiovascular risk information.
21. A method as in claim 15 including deriving bone assessment information by computer processing that uses said x-ray measurements, and wherein the reporting comprises showing the cardiovascular assessment information and the bone assessment information.
22. A method as in claim 21 in which the reporting comprises showing the cardiovascular risk information and the bone assessment information at different displays or documents.
23. A method as in claim 21 in which the reporting comprises showing the cardiovascular risk information and the bone assessment information concurrently.
24. A method as in claim 23 in which the reporting comprises showing the cardiovascular risk information and the bone assessment information at same display or document.
25. A method as in claim 15 including displaying information related to treatment guidelines related to the cardiovascular risk information.
26. A method as in claim 15 in which the obtaining of x-ray measurements comprises scanning the patient with a fan beam of x-rays.
27. A system comprising:
a dual x-ray energy range bone densitometer obtaining dual energy range x-ray measurements of a patient's anatomy that includes a selected portion of the patient's aorta;
a computer coupled with the densitometer and receiving said x-ray measurements therefrom, said computer being programmed to:
(a) process the x-ray measurements and thereby derive digital image information describing an image of at least the selected portion of the patient's aorta,
(b) process the digital image information and thereby produce aortic calcification information describing at least one selected calcification property of the selected portion of the aorta, and
(c) process the aortic calcification information and thereby estimate cardiovascular risk information related to an assessment of risk of a cardiovascular event for the patient; and
a display coupled with the computer and receiving said cardiovascular risk information therefrom and displaying an indication of a cardiovascular risk for the patient.
28. A system as in claim 27 wherein said computer is further programmed to process the digital image information and thereby calculate bone assessment information for the patient.
29. A system as in claim 28 wherein said display is coupled with said computer to receive the bone assessment information therefrom and displays an indication of the bone assessment information.
30. A system as in claim 28 in which said bone assessment information comprises bone fracture risk information.
31. A system as in claim 28 in which said bone assessment information comprises information related to at least one of bone mineral content and bone mineral density.
32. A system as in claim 21 in which said bone assessment information comprises bone fracture risk information.
33. A system as in claim 27 in which said digital image data comprises pixel values for respective pixels of a two-dimensional image of the patient's anatomy, and wherein said computer is programmed to carry out at least one pixel-based search algorithm in a process producing said aortic calcification information.
34. A system as in claim 27 in which said densitometer comprises a source of a fan-shaped beam of x-rays and a detector for x-rays traveling within respective sectors of said fan beam.
35. A computer readable medium carrying out one or more sequences of instructions stored therein in a non-transitory form, wherein execution of the one or more sequences of instructions by one or more processors causes the one or more processors to perform the steps of:
receiving at dual energy range x-ray measurements taken as a projection view of a patient's anatomy that includes a selected portion of the patient's aorta, said projection view having been taken at a substantially lower x-ray dose to the patent than a radiography or a CT slice-based image of the same anatomy;
processing the x-ray measurements to derive digital image information describing an image of at least the selected portion of the patient's aorta,
processing the digital image information to produce aortic calcification information describing at least one selected calcification property of the selected portion of the aorta,
processing the aortic calcification information to estimate cardiovascular risk information related to an assessment of risk of a cardiovascular event for the patient; and
displaying an indication of the estimated cardiovascular risk for the patient.
36. A computer readable medium as in claim 35 in which said x-ray measurements are taken in a lateral view of the patient.
37. A computer readable medium as in claim 35 in which said processing further comprises using said x-ray measurements to derive bone assessment information and said displaying further comprises displaying the bone assessment information.
38. A computer readable medium as in claim 37 in which said bone assessment information comprises bone fracture risk assessment information.
39. A computer readable medium as in claim 37 in which said bone assessment information comprises information related to at least one of bone mineral content and bone mineral density.
40. A computer readable medium as in claim 37 in which said digital image data comprises pixel values for respective pixels of a projection image of the patient's anatomy, and said processing comprises applying at least one pixel-based search algorithm in a process producing said aortic calcification information.