Back to results
US 5,291,021 AGranted
Positron computed tomography scanner
AssigneeHamamatsu Photonics K.K.
InventorsEiichi Tanaka, Nakahiro Satoh, Keiji Shimizu
Life of this patent
Estimating the term…
Abstract
A positron CT scanner includes a plurality of detectors arranged in a generally cylindrical multi-layers of rings, and slice septa for restricting visual fields of the detectors so that the visual fields intersect a set axis. An interval of the slice septa is substantially corresponds to a plural number of detector cells each of which can determine positions of .gamma. rays incident in the direction of the set axis. The slice septa are movable relatively to the detector cells in the direction of the set axis during a .gamma. ray counting operation.
Claims53
A positron CT scanner comprising:
- a plurality of detectors arranged in multi-layer rings about a predetermined central axis, each detector having at least one detecting cell;
- slice septa comprising a plurality of annular members formed about a non-parallel axis relative to the central axis, the annular members axially spaced along the non-parallel axis to define inter-member intervals along the non-parallel axis;
- and
- means for moving said slice septa during image detection about the central axis to cause the inter-septa intervals to move relative to said detecting cells.
1 more element
A positron CT scanner comprising:
- a plurality of detectors arranged in multi-layer rings about a predetermined central axis, each detector having at least one detecting cell;
- slice septa comprising a plurality of septa for restricting the detection fields of the detectors so that the detection fields intersect the predetermined axis by an interval in the direction of the predetermined axis corresponding to a selected number of the detecting cells;
- and
- means for driving the slice septa in a first direction along the predetermined axis and the opposite direction along the predetermined axis during a detection operation to cause the septa to move relative to the detecting cells.
1 more element
A positron CT scanner comprising:
- a plurality of detectors arranged in multi-layer rings about a predetermined central axis, each detector having at least one detecting cell;
- slice septa comprising a plurality of annular members concentric with the predetermined axis and aligned non-normal to the predetermined axis, and a holder for retaining a relative positional relationship with the detectors, said slice septa restricting detection fields of the detectors so that the detection fields intersect the predetermined axis by an interval in the direction of the predetermined axis corresponding to a plural number of the detecting cells;
- and
- means for driving the slice septa in a first direction and the opposite direction along the predetermined axis during a detection operation, to cause the septa to move relative to the detecting cells.
1 more element
A positron CT scanner comprising:
- a plurality of detectors arranged in multi-layer rings about a predetermined central axis, each detector having at least one detecting cell;
- slice septa comprising a single helical plate member advancing in the direction of the predetermined axis, and a holder of the member, for restricting detection fields of the detectors so that the detection fields intersect the predetermined axis by an interval in the direction of the predetermined axis corresponding to a plural number of the detecting cells;
- and
- means for driving the slice septa in a first direction and the opposite direction along the predetermined axis during a detection operation, to cause the septa to move relative to the detecting cells.
1 more element
A positron CT scanner comprising:
- a plurality of detectors arranged in multi-layer rings about a predetermined central axis, each detector having at least one detecting cell;
- slice septa means comprising a plurality of annular members axially spaced in the direction of the predetermined axis, and a holder for retaining a relative positional relationship with detectors, said slice septa means for restricting detection fields of the detectors so that the detection fields intersect the predetermined axis by an interval in the direction of the predetermined axis corresponding to a plural number of the detecting cells;
- and
- means for driving the slice septa means during image detection in a first direction and the opposite direction along the predetermined axis to cause the septa means to move relative to the detecting cells.
1 more element
A positron CT scanner comprising:
- a plurality of detectors arranged in multi-layer rings about a predetermined central axis, each detector having at least one detecting cell;
- slice septa comprising a plurality of curved sectors, each curved sector being offset with respect to one another in the direction of the predetermined axis, and a holder for retaining a relative positional relationship thereof with the detectors, the slice septa for restricting detection fields of the detectors so that the detection fields intersect the predetermined axis by an interval in the direction of the predetermined axis corresponding to a plural number of the detecting cells;
- and
- means for driving the slice septa in a first direction and the opposite direction along the predetermined axis during a detection operation, to cause the septa to move relative to the detecting cells.
1 more element
A positron CT scanner comprising:
- a plurality of detectors arranged in multi-layer rings about a predetermined central axis, each detector having a detection field in the direction of the predetermined central axis and having at least one detecting cell for detecting incident energy from positron-electron annihilations from an object within the detection field of a respective detector;
- means for defining a plurality of field-of-view intervals along the predetermined central axis for restricting the detection fields of the detectors along the predetermined central axis;
- and
- means for moving the first-mentioned means during detection so that said field-of-view intervals are moved in a first direction along the predetermined axis and in the opposite direction along the predetermined axis to cause the field-of-view intervals to move relative to the detectors in the first direction and then in the opposite direction along the predetermined axis.
1 more element
Dependencies are inferred from the claim text.