Projection data acquisition apparatus

A projection data acquisition method for acquiring projection data, the projection data acquisition method comprising:

• generating a pulsed radiation beam with a radiation source for traversing an object by a radiation device with a grid switching x-ray source,
• generating projection data being indicative of the pulsed radiation beam after having traversed the object by a detection device,
• moving the radiation device and the object relative to each other by a moving unit, in order to generate the projection data at different acquisition positions of the radiation device relative to the object,
• wherein the radiation device generates the pulsed radiation beam such that at different acquisition positions the pulsed radiation beam has different shapes,
• wherein the collimator comprises a rotatable cylinder with several openings, and is adapted to rotate the cylinder such that the openings are arranged at different rotational positions relative to the radiation source at the different acquisition positions such that at the different acquisition positions the pulsed radiation beam has different shapes,
• wherein the openings of the cylinder include first openings arranged at a first position along a longitudinal axis of the cylinder and second openings arranged at a second position along the longitudinal axis of the cylinder, wherein the first openings and the second openings have a circumferential offset relative to each other,
• wherein the first and second openings are rectangular,
• wherein the collimator partially blocks the radiation beam such that a shadowed region and a non-shadowed region are generated on the detection device,
• wherein the detection device generates the projection data based on the pulsed radiation beam directed onto the non-shadowed region and to generate scatter data based on radiation, which has been scattered onto the shadowed region,
• wherein the generated projection data are corrected based on the scatter data by using a correction unit.

A non-transitory computer storage medium encoded with computer readable instructions, which, when executed by a processor of a computing system, causes the processor to perform acts of:

• generating a pulsed radiation beam with a radiation source for traversing an object by a radiation device with a grid switching x-ray source;
• generating projection data being indicative of the pulsed radiation beam after having traversed the object by a detection device;
• and
• moving the radiation device and the object relative to each other by a moving unit, in order to generate the projection data at different acquisition positions of the radiation device relative to the object,
• wherein a collimator partially blocks the radiation beam such that a shadowed region and a non-shadowed region are generated on the detection device,
• wherein the collimator comprises a rotatable cylinder with several openings, and is adapted to rotate the cylinder such that the openings are arranged at different rotational positions relative to the radiation source at the different acquisition positions such that at the different acquisition positions the pulsed radiation beam has different shapes,
• wherein the openings of the cylinder include first openings arranged at a first position along a longitudinal axis of the cylinder and second openings arranged at a second position along the longitudinal axis of the cylinder, wherein the first openings and the second openings have a circumferential offset relative to each other,
• wherein the first and second openings are rectangular,
• wherein the radiation device generates the pulsed radiation beam directed onto the non-shadowed region.