BACKGROUND

Field of the Invention

The present application relates generally to a multiposition collimation device for an x-ray source and x-ray imaging systems that use the multiposition collimation device.

Description of Related Art

X-ray radiography can be performed by positioning an x-ray source on one side of an object (e.g., a patient or a portion thereof) and emitting x-rays from that source, through the object, and toward an x-ray detector (e.g., radiographic film, an electronic digital detector, or a photostimulable phosphor plate) located on the other side of the object. As the x-rays pass through the object they are attenuated to varying degrees depending on the composition of the object. X-rays arriving at the x-ray detector form a two-dimensional (2D) x-ray image (also known as a radiograph) based on the cumulative absorption through the object.

Tomosynthesis provides three-dimensional information about a patient in the form of tomographic image slices reconstructed from x-ray images of the patient taken from multiple perspectives within a scan angle smaller than that of computed tomography (CT) or cone-beam computed tomography (CBCT) (e.g., ±20°, compared with at least 180° in CBCT).

In order to limit x-ray exposure to only those areas of diagnostic inquiry, it is beneficial to collimate the x-ray beam so that only the patient's volume of interest (the region of space relevant to the diagnostic inquiry) is radiated. It is also beneficial to ensure that the x-ray source is correctly positioned and aligned with respect to the x-ray detector. Therefore, it would be desirable to have a collimation device which could provide beneficial collimation and aid in the positioning and alignment during a tomosynthesis imaging operation.

SUMMARY OF THE INVENTION

One or more the above limitations may be diminished by collimation devices and x-ray imaging systems described herein.

In one embodiment, a collimation device for a dental imaging apparatus is provided. The collimation device includes a collimator housing and a collimator plate constructed to at least partially block the passage of x-rays. The collimator plate is movable relative to the collimator housing to a first position, corresponding to a first x-ray detector size, and a second position, corresponding to a second x-ray detector size.

In another embodiment, an x-ray imaging system is provided. The x-ray imaging system includes an x-ray source, configured to generate an x-ray beam, and a collimation device. The collimation device is connected to the x-ray source and includes: a collimator housing and a collimator plate. The collimator plate is constructed to at least partially block the passage of x-rays. The collimator plate is movable relative to the collimator housing to a first position, corresponding to a first x-ray detector size, and a second position, corresponding to a second x-ray detector size. The collimation device is arranged to receive the x-ray beam generated by the x-ray source.

