Apparatus for partial CT imaging comprising a collimator to center a radiation beam toward a region of interest spaced apart from a rotation axis

A method for computed tomography imaging of a patient, comprising:

• providing a rotatable mount that is actuable to rotate about a rotation axis and the rotatable mount comprises, in opposition, an x-ray source and an x-ray detector for obtaining a plurality of frame images;
• directing, at each of a plurality of angular positions of the rotatable mount about the rotation axis, a radiation beam from the x-ray source through an imaging area;
• providing a patient positioning apparatus for positioning relative to the rotation axis;
• providing a collimator between the x-ray source and the imaging area;
• directing, at said each of the plurality of angular positions of the rotatable mount about the rotation axis, the radiation beam from the x-ray source through the collimator and the imaging area, wherein the x-ray detector is of a smaller size that is irradiated with the radiation beam through the collimator and the imaging area;
• moving the collimator to direct the radiation beam, at said each of the plurality of angular positions, toward a region of interest that is spaced apart from the rotation axis;
• and
• moving the x-ray detector to a plurality of different positions along a detector track according to a mount angle of the rotatable mount at said each of the plurality of angular positions and detected coordinates for an opening of the collimator at said each of the plurality of angular positions;
• and moving the x-ray detector to form image data including a frame image at each of the plurality of different positions along the detector track according to the radiation beam during a computed tomography scan, wherein the x-ray detector moves in opposite directions along the detector track during the computed tomography scan.

A method for computed tomography imaging of a patient, comprising:

• providing a rotatable mount that is actuable to rotate about a rotation axis and the rotatable mount comprises, at opposing ends, an x-ray source having a collimator and an x-ray detector for obtaining a plurality of frame images, wherein the x-ray source is disposed to direct a radiation beam through the patient and toward the x-ray detector;
• accessing a region of interest of the patient, the region of interest having a center that is spaced apart from the rotation axis;
• positioning the rotatable mount at a first angular position;
• calculating the position of a center of an opening of the collimator at the first angular position for centering a radiation beam about the center of the region of interest;
• acquiring a frame image at the first angular position;
• rotating the rotatable mount to at least one second angular position;
• changing the position of the center of the opening of the collimator at the at least one second angular position for centering a radiation beam about the center of the region of interest;
• acquiring a frame image at the at least one second angular position;
• forming a volume image according to at least image data acquired at the first angular position and the at least one second angular position;
• and
• displaying, transmitting, or storing the volume image;
• changing the position of the opening of the collimator relative to a vertical direction;
• and
• storing one or more coordinates that identify the region of interest having the center that is spaced apart from the rotation axis.