EP0713676A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
X-ray bone densitometry
Assignee: Hologic Inc
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Filing: 1995-11-24
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Granted: —
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Expires: 2015-11-24
Abstract
Abstract An x-ray bone densitometry apparatus having a patient table with a length extending along a Y-axis and a width extending along an X-axis and a C-arm supporting an x-ray source at one side and an x-ray detector at an opposite side of the table such that the source and detector are aligned along a source-detector axis which is transverse to the Y-axis. The source is selectively energized to emit a fan beam of x-rays which conform to a beam plane which is transverse to the Y-axis and contains the source-detector axis. Either, or both, the C-arm or the table are selectively movable relative to the other along the X-axis, along the Y-axis, and along a Z-axis which is transverse to both the X-axis and the Y-axis so that selected regions of a patient on the table can be selectively scanned with the fan beam of X-rays. In addition, the C-arm is selectively rotatable around a rotational axis extending along the Y-axis to selectively change the angle of the fan beam with respect to a patient on the table.
Inventors
- 👤 Jay A. Stein
- 👤 Steven Teta
- 👤 Donald Barry
- 👤 Richard E. Cabral
- 👤 Tracy L. Ramsdell
- 👤 Tina Lefebvre
- 👤 Noah Berger
- 👤 Tom Richardson
- 👤 Eric Von Stetten
- 👤 Howard P. Weiss
- 👤 Thomas L. Kelly
- 👤 Russell J. Gershman
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-10 01:18
CPC Classifications
G; G21; G21K; G21K1/00; G21K1/10; A; A61; A61B; A61B6/00; A61B6/04; A61B6/0407; A61B6/0421; A61B6/06; A61B6/08; A61B6/40; A61B6/405; A61B6/48; A61B6/482; A61B6/488; A61B6/50; A61B6/505; A61B6/54; A61B6/548; A61B6/58; A61B6/582; A61B6/583
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
170 words
An x-ray bone densitometry apparatus comprising: a patient table having a length extending along a Y-axis and a width extending along an X-axis; a C-arm supporting an x-ray source at one side and an x-ray detector at an opposite side of said table; said source and detector being aligned along a source-detector axis which is transverse to the Y-axis; said source when selectively energized emitting a fan beam of x-rays which conforms to a beam plane which is transverse to the Y-axis and contains the source-detector axis; at least one of said C-arm and table being selectively movable relative to the other along the X-axis, along the Y-axis, and along a Z-axis which is transverse to both the X-axis and the Y-axis to selectively scan selected regions of a patient on the table with said fan beam of x-rays; and said C-arm being selectively rotatable around a rotational axis extending along the Y-axis to selectively change the angle of the fan beam with respect to a patient on the table.
Claim 2
Dependent Claim
83 words
An x-ray bone densitometry apparatus as in claim 1 further comprising: a beam modulator mounted between the x-ray source and the table for rotation about a beam modulator axis which is transverse to the source-detector axis; said beam modulator being selectively rotatable about the beam modulator axis to cause the fan beam of x-rays to pass through a succession of beam modulating materials before reaching a patient on the table; said beam modulating materials having respective different effects on the x-rays impinging thereon.
Claim 3
Dependent Claim
64 words
An x-ray bone densitometry apparatus as in claim 1 further comprising: an attenuator selector mounted between the x-ray source and the table; said attenuator selector having a plurality of attenuating materials selectively movable to cause the fan beam to pass therethrough; and each of the attenuating materials attenuating the fan beam passing therethrough in a selected manner different from that of other attenuating materials.
Claim 4
Dependent Claim
83 words
An x-ray bone densitometry apparatus as in claim 1 further comprising: a variable aperture collimator mounted between the x-ray source and the table to define the cross-section of the fan beam; said variable aperture collimator comprising a pair of plates selectively movable along the Y-axis to define one of the cross-sectional dimensions of the fan beam and a pair of plates movable along a direction transverse to both the Y-axis and the source-detector axis to define another cross-sectional dimension of the fan beam.
Claim 5
Dependent Claim
73 words
An x-ray bone densitometry apparatus as in claim 1 further comprising: detector elements forming a part of said detector and providing respective detector outputs related to the x-rays received at respective angular positions within the fan beam; and a detector response flattener responsive to said detector outputs to process said outputs to account for at least one of: (i) non-uniformities in the fan beam; and (ii) non-uniformities in the response of detector elements.
Claim 6
Dependent Claim
84 words
An x-ray bone densitometry apparatus as in claim 1 further comprising: detector elements forming a part of said detector and providing respective detector outputs related to the x-rays received at respective angular positions within the fan beam; a dark current system for interleaving the detector outputs with dark current responses of the detector elements on a substantially continuous basis; and a dark current corrector responsive to the detector outputs and the dark current responses to account for dark current characteristics of the detector elements.
Claim 7
Dependent Claim
43 words
An x-ray bone densitometry apparatus as in claim 1 further comprising: an optical crosshairs device mounted on the C-arm to project a visible crosshairs co-axial with the source-detector axis and having a plane along the Y-axis and a plane normal to the Y-axis.
Claim 8
Dependent Claim
113 words
An x-ray bone densitometry apparatus as in claim 1 further comprising: a scan motion controller moving at least one of the C-arm and the table relative to the other to scan at least a first region and then a second region of a patient on the table with the fan beam along the Y-axis; said first region and said second region being next to each other along the X-axis, each having an edge overlapping an adjacent edge of the other region; the distance along the Z-axis from an origin of the fan beam in the source to the table being the same for the scan of each of the first and second regions.
Claim 9
Dependent Claim
78 words
An x-ray bone densitometry apparatus as in claim 8 further comprising: a merger responsive to outputs of the detector for scans of the first and second regions to merge detector outputs for positions of the fan beam which are spatially adjacent along the X-axis but are obtained at different times, into resulting merged detector outputs corresponding to detector outputs obtainable from a single fan beam having substantially twice the width of the fan beam emitted from the source.
Claim 10
Dependent Claim
93 words
An x-ray bone densitometry apparatus as in claim 1 further comprising: a source controller selectively pulsing the source to emit therefrom single energy and dual energy x-rays in time-interleaved manner; a processor responsive to detector outputs for said single and dual energy x-rays to derive therefrom diagnostic information based solely on single energy x-rays as well as diagnostic information based on said dual energy x-rays; and a display coupled with the processor to display concurrently both the diagnostic information based on single energy x-rays and the diagnostic information based on dual energy x-rays.
Claim 11
Dependent Claim
110 words
An x-ray bone densitometry apparatus as in claim 1 further comprising: a scan motion controller moving at least one of the C-arm and the table relative to the other to carry out first a posterior/anterior or an anterior/posterior scan and then a lateral scan of a patient on the table without moving the patient between the two views; said scan motion controller rotating the C-arm around the rotation axis thereof between the two scans; and said scan motion controller selecting the position of the source relative to the table for the lateral scan based on information respecting the patient's spine obtained in the course of the anterior/posterior or posterior/anterior scan.
Claim 12
Dependent Claim
76 words
An x-ray bone densitometry apparatus as in claim 1 further comprising: a scan motion controller storing scan sequences each corresponding to scanning a selected set of regions of interest in a patient on the table; and an interface responsive to operator input to select a stored scan sequence, said scan motion controller being coupled to said interface to carry out a scan sequence selected by an operation through said interface to carry out the selected sequence.
Claim 13
Dependent Claim
116 words
An x-ray bone densitometry apparatus as in claim 1 further comprising: a patient positioner removably supported on the table; said patient positioner having: (i) a base for supporting the head and upper shoulders of a patient who is supine on the table; and (ii) a pair of wings spaced from each other along the X-axis and extending up from the base for supporting the patient's arms when the patient's hands are under the patient's head and the elbows are to the left and right of, and elevated from, the patient's torso; said patient positioner being shaped and dimensioned to maintain the patient's arms and hands away from the patient's chest and to straighten the patient's spine.
Claim 14
Dependent Claim
97 words
An x-ray bone densitometry apparatus as in claim 1 further comprising: a forearm positioner removably supported on the table at a selected distance along the X-axis from an edge of the table; said forearm positioner comprising a base with an opening therein corresponding to a position for a patient's wrist when the patient's forearm extends along the Y-axis and is held against the table, and further comprising a fence against which the patient's forearm can be pressed to limit movement of the patient's forearm along the X-axis in a direction away from said edge of the table.
Claim 15
Dependent Claim
105 words
An x-ray bone densitometry apparatus as in claim 1 further comprising: a scan motion controller maintaining the C-arm and the table at a selected relative position along the Y-axis but selectively causing other relative motion between the C-arm and the table to obtain dual energy detector outputs for different relative positions between the C-arm and table while a patient is on the table; processing the dual energy detector outputs to substantially cancel out soft tissue information while retaining bone information in the detector outputs; and forming a computerized tomography image reconstructing bone structure but not soft tissue structure for which detector outputs have been obtained.
Claim 16
Dependent Claim
38 words
An x-ray bone densitometer in which a table for supporting a patient and an x-ray source and detector combination for emitting and detecting x-rays passing through the table are movable relative to each other along three orthogonal axes.
Claim 17
Dependent Claim
41 words
An x-ray bone densitometer in which an x-ray source and detector combination is rotatable relative to a table for supporting a patient so as to vary the angle at which x-rays from the source pass through the table to the detector.
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