PURPOSE: In this article, the authors propose a multibeam field emission x-ray (MBFEX) system along with a half-scan fan-beam reconstruction algorithm. METHODS: The proposed system consists of a linear CNT-based MBFEX source array, a single large area detector that is divided into same number of segments as the number of x-ray beams, a multihole collimator that aligns each beam with a corresponding detector segment, and a sample rotation stage. The collimator is placed between the source and the object to restrict the x-ray radiations through the target object only. In this design, all the x-ray beams are activated simultaneously to provide multiple projection views of the object. The detector is virtually segmented and synchronized with the x-ray exposure and the physiological signals when gating is involved. The transmitted x-ray intensity from each beam is collected by the corresponding segment on the detector. After each exposure, the object is rotated by a step angle until sufficient data set is collected. The half-scan reconstruction formula for MBFEX system is derived from the conventional filtered backprojection algorithm. To demonstrate the advantages of the system and method in reducing motion artifacts, the authors performed simulations with both standard and dynamic Shepp-Logan phantoms. RESULTS: The numerical results indicate that the proposed multibeam system and the associated half-scan algorithm can effectively reduce the scanning time and improve the image quality for a time-varying object. CONCLUSIONS: The MBFEX technique offers an opportunity for the innovation of multisource imaging system.
PURPOSE: In this article, the authors propose a multibeam field emission x-ray (MBFEX) system along with a half-scan fan-beam reconstruction algorithm. METHODS: The proposed system consists of a linear CNT-based MBFEX source array, a single large area detector that is divided into same number of segments as the number of x-ray beams, a multihole collimator that aligns each beam with a corresponding detector segment, and a sample rotation stage. The collimator is placed between the source and the object to restrict the x-ray radiations through the target object only. In this design, all the x-ray beams are activated simultaneously to provide multiple projection views of the object. The detector is virtually segmented and synchronized with the x-ray exposure and the physiological signals when gating is involved. The transmitted x-ray intensity from each beam is collected by the corresponding segment on the detector. After each exposure, the object is rotated by a step angle until sufficient data set is collected. The half-scan reconstruction formula for MBFEX system is derived from the conventional filtered backprojection algorithm. To demonstrate the advantages of the system and method in reducing motion artifacts, the authors performed simulations with both standard and dynamic Shepp-Logan phantoms. RESULTS: The numerical results indicate that the proposed multibeam system and the associated half-scan algorithm can effectively reduce the scanning time and improve the image quality for a time-varying object. CONCLUSIONS: The MBFEX technique offers an opportunity for the innovation of multisource imaging system.
Authors: G Cao; Y Z Lee; R Peng; Z Liu; R Rajaram; X Calderon-Colon; L An; P Wang; T Phan; S Sultana; D S Lalush; J P Lu; O Zhou Journal: Phys Med Biol Date: 2009-03-25 Impact factor: 3.609