Systems and methods for calibrating radiation device

A method for calibrating a radiation device implemented on a computing device having one or more processors and one or more storage devices, the radiation device includes a radiation source, a collimator, and a detector of an imaging device disposed opposite to the radiation source, the radiation source being configured to emit a radiation beam, the collimator being configured to block the radiation beam, the method comprising:

• obtaining a plurality of images acquired at each source-to-image distances (SID) of a plurality of SIDs by the imaging device, wherein the plurality of images include at least one first image and at least one second image, the at least one first image is obtained by rotating the collimator around the first axis of the collimator, and the at least one second image is obtained by imaging a phantom from at least one gantry angle;
• determining, based on the at least one first image, a first projection position of a first axis of the collimator on the imaging device associated with the each SID of the plurality of SIDs;
• determining, based on the at least one second image, a second projection position of a second axis of the radiation beam on the imaging device associated with the each SID of the plurality of SIDs;
• determining, based on the first projection position of the first axis of the collimator on the imaging device associated with the each SID of the plurality of SIDs and the second projection position of the second axis of the radiation beam on the imaging device associated with the each SID of the plurality of SIDs, an offset distance associated with the each SID of the plurality of SIDs;
• and
• determining, based on the plurality of SIDs and the offset distance associated with the each SID of the plurality of SIDs, a deviation between the first axis of the collimator and the second axis of the radiation beam.

A method for calibrating a radiation device implemented on a computing device having one or more processors and one or more storage devices, the radiation device includes a radiation source, a collimator, and a detector of an imaging device disposed opposite to the radiation source, the radiation source being configured to emit a radiation beam, the collimator being configured to block the radiation beam, the method comprising:

• obtaining at least one first image acquired at a first source-to-image distance (SID) by the imaging device;
• obtaining at least one second image acquired at a second SID by the imaging device, wherein the at least one first image and the at least one second image are obtained by rotating the collimator around the first axis of the collimator;
• determining at least one projection position of a first axis of the collimator on the imaging device based on the at least one first image and the at least one second image, the at least one projection position of the first axis of the collimator on the imaging device includes a first projection position of the first axis of the collimator on the imaging device when the imaging device is positioned to acquire the at least one first image at the first SID, and a second projection position of the first axis of the collimator on the imaging device when the imaging device is positioned to acquire the at least one second image at the second SID;
• obtaining at least one third image acquired at the first SID by the imaging device;
• obtaining at least one fourth image acquired at the second SID by the imaging device, wherein the at least one third image and the at least one fourth image are obtained by imaging a phantom from at least one gantry angle;
• determining at least one projection position of a second axis of the radiation beam on the imaging device based on the at least one third image and the at least one fourth image, the at least one projection position of the second axis of the radiation beam on the imaging device includes a third projection position of the second axis of the radiation beam on the imaging device when the imaging device is positioned to acquire the at least one third image at the first SID, and a fourth projection position of the second axis of the radiation beam on the imaging device when the imaging device is positioned to acquire the at least one fourth image at the second SID;
• determining, based on the at least one first image and the at least one third image, a first offset distance between the first projection position and the third projection position;
• determining, based on the at least one second image and the at least one fourth image, a second offset distance between the second projection position and the fourth projection position;
• and
• determining, based on the first offset distance, the second offset distance, the first SID, and the second SID, a deviation between the first axis of the collimator and the second axis of the radiation beam.