Imaging mode for linear accelerators

An apparatus comprising:

• an input device to receive a first instruction to enter an imaging mode, and a second instruction to enter a first radiation treatment mode;
• an accelerator waveguide to emit a radiation beam;
• a first device to reduce a focal spot size of a radiation beam in response to the first instruction, and to increase a focal spot size of the radiation beam in response to the second instruction;
• a second device to move a flattening filter out of a path of the radiation beam in response to the first instruction, and to move the flattening filter into the path of the radiation beam in response to the second instruction;
• a third device to move a first target for photon emission out of the path of the radiation beam and to move a second target for photon emission into the path of the radiation beam in response to the first instruction, and to move the second target out of the path of the radiation beam and to move the first target into the path of the radiation beam in response to the second instruction;
• and
• a fourth device to move a scatter-reducing filter into the path of the radiation beam in response to the first instruction, and to move the scatter-reducing filter out of the path of the radiation beam in response to the second instruction.

A medium storing program code, the program code comprising:

• code to receive a first instruction to enter an imaging mode;
• code to, in response to the first instruction, automatically reduce a focal spot size of a radiation beam, move a flattening filter out of a path of the radiation beam, move a first target for photon emission out of the path of the radiation beam and move a second target for photon emission into the path of the radiation beam, and move a scatter-reducing filter into the path of the radiation beam;
• code to receive a second instruction to enter a first radiation treatment mode;
• and
• code to, in response to the second instruction, automatically perform at least one of:
• increase a focal spot size of the radiation beam, move the flattening filter into the path of the radiation beam, move the second target out of the path of the radiation beam and move the first target into the path of the radiation beam, and move the scatter-reducing filter out of the path of the radiation beam.