A TECHNIQUE FOR GENERATING MULTIPLE ENERGY X-RAY IMAGES
Publication Date: 2016-Dec-10
The IP.com Prior Art Database
A technique for generating multiple energy X-ray images is proposed. According to the proposed technique, multiple X-ray sources are mounted on a gantry in axial direction for acquiring multiple energy data and performing quantitative reconstruction. Further, different filtration material is added to enhance the spectral separation between the different energy portions on the detector. A weighted image reconstruction algorithm which uses the knowledge of the regions on the detector where different energy spectrum is used is generated. Thereby, images which are largely reconstructed from separate given energy spectrum are generated and input to an image space decomposition.
The present disclosure relates generally to computed tomography and more particularly to a technique for generating multiple energy X-ray images.
In computed tomography (CT) majority of clinical exams are acquired using a single energy spectrum and energy integrating detector. Reconstruction problem in techniques using single energy spectrums is to reconstruct average attenuation coefficient over the effective energy spectrum of the source and detector system.
In recent years several multiple energy methods depicted in Figure 1 have been proposed which provide the ability to reconstruct attenuation due to the photo-electric and Compton effects or material basis images such as the projection onto the water basis or onto the iodine basis. The multiple energy techniques offer improved quantification compared to single energy acquisitions. However, CT machines capable of producing multiple energy acquisitions remain a challenge. A conventional clinical implementation required either two complete X-ray detector systems, a completely redesigned sandwiched layer detector or a very fast switching generator and a detector with a very rapid primary decay time. These requirements limited true multiple energy acquisitions to the premium CT scanners.
Another conventional technique proposed using a special z dependent collimation and a low pitch acquisition to obtain dual energy acquisitions. This technique has the advantage of ease of implementation but the disadvantage of requiring very heavy filtration in order to achieve the desired spectral separation.
It would be desirable to have an improved technique for generating multiple energy X-ray images.
BRIEF DESCRIPTION OF DRAWINGS
Figure 1 depicts a comparison of conventional techniques for generating multiple energy X-ray data using conventional energy integrating detectors.
A technique for generating multiple energy X-ray images is proposed. According to the proposed technique, multiple X-ray sources are mounted on a gantry in axial direction for acquiring multiple energy data and performing quantitative reconstruction.
According to the proposed technique, X-ray projection data is acquired from the multiple X-ray sources mounted in the axial direction along the direction of the table. Each of the multiple X-ray sources is programmed with a different tube potential for generating multiple energy images. Further, different fi...