Imaging systems and methods for extending truncated projection data

An imaging method, comprising:

• obtaining reference data including a complete projection of an object;
• wherein the reference data includes projection data acquired by scanning, from a non-truncated projection view, the object using a radiation device, in the non-truncated projection view, the object is within a field of view (FOV) of the radiation device, and the non-truncated projection view is determined by a first process including:
• obtaining at least one second image of the object, the at least one second image being acquired by at least one camera at a plurality of candidate projection views, the at least one camera being positioned on a gantry of the radiation device, an FOV of the at least one camera being consistent with the FOV of the radiation device;
• identifying, based on the at least one second image, one or more of the plurality of candidate projection views in which the object is completely within the FOV of the at least one camera;
• and
• selecting, as the non-truncated projection view, one of the one or more of the plurality of candidate projection views;
• obtaining original projection data of the object, the original projection data being acquired by scanning the object using the radiation device from one or more imaging projection views, the original projection data including truncation projection data that is acquired from at least one of the one or more imaging projection views, in each of the at least one of the one or more imaging projection views a truncation region of the object being located outside the FOV of the radiation device;
• determining extended projection data corresponding to the at least one truncation region by performing, based on the original projection data and the reference data, a mirror extrapolation algorithm;
• and
• generating a first image of the object based on the original projection data and the extended projection data.

A non-transitory computer readable medium, comprising executable instructions that, when executed by at least one processor, direct the at least one processor to perform a method, the method comprising:

• obtaining reference data including a complete projection of an object;
• wherein the reference data includes projection data acquired by scanning, from a non-truncated projection view, the object using a radiation device, in the non-truncated projection view, the object is within a field of view (FOV) of the radiation device, and the non-truncated projection view is determined by a first process including:
• obtaining at least one second image of the object, the at least one second image being acquired by at least one camera at a plurality of candidate projection views, the at least one camera being positioned on a gantry of the radiation device, an FOV of the at least one camera being consistent with the FOV of the radiation device;
• identifying, based on the at least one second image, one or more of the plurality of candidate projection views in which the object is completely within the FOV of the at least one camera;
• and
• selecting, as the non-truncated projection view, one of the one or more of the plurality of candidate projection views;
• obtaining original projection data of the object, the original projection data being acquired by scanning the object using the radiation device from one or more imaging projection views, the original projection data including truncation projection data that is acquired from at least one of the one or more imaging projection views, in each of the at least one of the one or more imaging projection views a truncation region of the object being located outside the FOV of the radiation device;
• determining extended projection data corresponding to the at least one truncation region by performing, based on the original projection data and the reference data, a mirror extrapolation algorithm;
• and
• generating a first image of the object based on the original projection data and the extended projection data.