Computed tomography image acquisition
AssigneeKoninklijke Philips Electronics N.V.
InventorsJinghan Ye, John F. Vesel, Michael J. Petrillo
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Abstract
A computed tomography acquisition geometry provides an increased field of view (218). A radiation source (202, 702) such as an x-ray source and a radiation detector (204, 704) are displaced from the imaging center (214). In one implementation, the central ray (216) of a radiation beam (212) is parallel to the plane of the detector (204, 704) at the detector midpoint (219, 719), but is displaced from the imaging center.
Claims29
An apparatus for acquiring tomographic projection data at a plurality of angular positions relative to an object disposed in an examination region, the apparatus comprising:
- a radiation source that emits a radiation beam from a first position and a second different position;
- a radiation sensitive detector which detects radiation emitted by the source, which radiation has traversed the examination region;
- wherein both the source and a transverse center of the detector are transversely displaced from a center of a transverse field of view during acquisition of the projection data, and
- wherein from the first position and from the second position, the radiation beam has a generally fan shaped transverse cross section, the cross section includes first and second outermost rays, and the outermost rays intersect the detector at equal angles of incidence.
A computed tomography method comprising:
- emitting first radiation from a location which is transversely displaced from a center of a transverse field of view, wherein the first radiation traverses a portion of the transverse field of view;
- using a radiation detector to acquire computed tomography projection data indicative of the first radiation, wherein the detector is transversely displaced from the center of the transverse field of view;
- repeating the steps of emitting first radiation and using the radiation detector to acquire computed tomography projection data indicative of the first radiation at each of a plurality of projection angles to acquire a first CT data set;
- reconstructing the first CT data set to generate first volumetric data.
A computed tomography apparatus comprising:
- an x-ray source, wherein the x-ray source is transversely displaced from and rotates about a center of rotation;
- an x-ray detector, wherein the x-ray detector detects radiation emitted by the x-ray source, wherein the x-ray detector is transversely displaced from the center of rotation and rotates about the center of rotation in a fixed mechanical relation to the x-ray source so as to acquire projection data at a plurality of projection angles, wherein the x-ray source emits radiation having a transverse fan angle, and wherein a complete angular sampling of a transverse field of view requires the acquisition of projection data over an angular range greater than 180° plus the fan angle;
- a reconstructor which reconstructs the projection data to generate volumetric data indicative of the transverse field of view.
Dependencies are inferred from the claim text.