Extremity imaging apparatus for cone beam computed tomography
View Patent ↗An apparatus for cone beam computed tomography can include a support structure, a scanner assembly coupled to the support structure for controlled movement in at least x, y and z orientations, the scanner assembly can include a DR detector configured to move along at least a portion of a detector path that extends at least partially around a scan volume with a distance D 1 that is sufficiently long to allow the scan volume to be positioned within the detector path; a radiation source configured to move along at least a portion of a source path outside the detector path, the source path having a distance D 2 greater than the distance D 1 , the distance D 2 being sufficiently long to allow adequate radiation exposure of the scan volume for an image capture by the detector; and a first gap in the detector path.
1. An apparatus for cone beam x-ray computed tomographic imaging, the apparatus comprising:
a digital x-ray radiation detector;
a detector mechanism attached to the detector and configured to move the detector along a detector path, a shape of the detector path comprising a first circular arc, the detector path defining a vertical detector axis whereat at least a portion of a patient is positioned to be imaged by the apparatus;
an x-ray radiation source;
a source mechanism attached to the source and configured to move the source along a source path, a shape of the source path comprising a second circular arc having a gap in the source path, the source path defining a source plane and a vertical source axis, the source axis coaxial with the detector axis; and
a housing comprising two opposing end surfaces defining a peripheral gap,
wherein the detector mechanism comprises a frame upon which the detector is attached, the frame comprising a section shaped as a portion of a cylinder, the cylinder portion having a central axis coaxial with the detector axis and having a height greater than a height of the detector, the source mechanism integrally attached to a portion of the frame such that the source and the detector can only move simultaneously, and
wherein a distance from the source path to the source axis is greater than a distance from the detector path to the detector axis.
2. The apparatus of claim 1 , wherein the apparatus is configured to allow one extremity of the patient to be positioned at the detector axis by moving the one extremity of the patient through the peripheral gap in a direction substantially perpendicular to the source axis.
3. The apparatus of claim 1 , wherein the source mechanism includes:
a rigid assembly to provide mechanical support for the source as the source is moved along the source path.
4. The apparatus of claim 3 , wherein the detector mechanism includes the rigid assembly to provide mechanical support for the detector as the detector is moved along the detector path.
5. The apparatus of claim 3 , wherein the rigid assembly comprises a C-shaped assembly configured to allow one extremity of the patient to be positioned at the detector axis by moving the one extremity of the patient through the gap in the C-shaped assembly.
6. The apparatus of claim 5 , wherein the detector path includes a gap in the first circular arc, and wherein at least a portion of the gap in the first circular arc is diametrically opposite at least a portion of the gap in the source path.
7. The apparatus of claim 5 , wherein the housing comprises a C-shape to enclose the source and the source mechanism as the source moves along the source path and to enclose the detector and the detector mechanism as the detector moves along a portion of the detector path.
8. The apparatus of claim 7 , wherein the C-shaped housing comprises a housing gap configured to allow the one extremity of the patient to be positioned at the detector axis by moving the one extremity of the patient through the housing gap in a direction substantially perpendicular to the detector axis.
9. The apparatus of claim 1 , wherein the housing comprises a C-shape to enclose the source, the source mechanism, the detector, and the detector mechanism, the C-shaped housing comprising:
a housing extension attached to the housing and configured to controllably extend from the housing across the peripheral gap to enclose the detector as the detector moves along the detector path across the peripheral gap.
10. The apparatus of claim 9 , wherein the housing extension is further configured to retract into the housing.
11. The apparatus of claim 9 , wherein the housing extension comprises a cross section along a plane coinciding with the central axis, the cross section of the housing extension having a tapered shape along at least one dimension of the cross section.
12. The apparatus of claim 1 , wherein the source mechanism includes a C-shaped turntable attached to the source to provide mechanical support for the source and to move the source along the source path.
13. An apparatus for cone beam x-ray computed tomographic imaging of one extremity of a patient, the apparatus comprising:
a digital x-ray radiation detector and an x-ray radiation source configured to simultaneously move around a central axis whereat at least a portion of the one extremity of the patient is positioned to be imaged by the apparatus; and
a C-shaped housing configured to enclose the source within the housing as the source moves around the central axis and to enclose the detector within the housing for a portion of the distance that the detector moves around the central axis, the detector configured to be manually removable from within the housing and the housing comprising a gap configured to allow the one extremity of the patient to be positioned at the central axis by moving at least a portion of the one extremity of the patient through the housing gap,
wherein the C-shaped housing comprises two opposing end surfaces at the housing gap, the end surfaces each parallel to a different plane coinciding with the central axis, and wherein at least one of the end surfaces comprises an opening through which the detector can be manually removed from within the housing.
14. The apparatus of claim 13 , further comprising a housing extension attached to the housing and configured to controllably extend from the housing and across the housing gap to enclose the detector when the detector moves around the central axis across the housing gap.
15. The apparatus of claim 14 , wherein the housing extension is configured to controllably extend across the housing gap after the one extremity of the patient is positioned at the central axis.
16. The apparatus of claim 15 , wherein the housing extension is further configured to controllably retract into the housing.
17. The apparatus of claim 15 , wherein the housing extension is configured to controllably extend across the housing gap between legs of the patient after one leg of the patient is positioned at the central axis.
18. The apparatus of claim 15 , wherein the detector is configured to move around the central axis at a first distance therefrom, the source is configured to move around the central axis at a second distance therefrom, and wherein the first distance is less than the second distance.