Objective:To evaluate and compare the diagnosti c value in atlantoaxial subluxation by CT three-dimensional (3D) reconstruction . Methods:3D reconstruction findings of 41 patients with atlanto axial subluxation were r...Objective:To evaluate and compare the diagnosti c value in atlantoaxial subluxation by CT three-dimensional (3D) reconstruction . Methods:3D reconstruction findings of 41 patients with atlanto axial subluxation were retrospectively analyzed, and comparisons were made among images of transverse section, multiplanar reformorting (MPR), surface shade dis play (SSD), maximum intensity project (MIP), and volume rendering (VR). Results:Of 41 patients with atlantoaxial subluxation, 31 belon ged to rotary dislocation, 5 antedislocation, and 5 hind dislocation. All the ca ses showed the dislocated joint panel of atlantoaxial articulation. Fifteen case s showed deviation of the odontoid process and 8 cases widened distance between the dens and anterior arch of the atlas. The dislocated joint panel of atlantoax ial articulation was more clearly seen with SSD-3D imaging than any other metho ds. Conclusions:Atlantoaxial subluxation can well be diagnosed by CT 3D reconstruction, in which SSD-3D imaging is optimal.展开更多
During the design process of Blu-ray disc optical pick-up （BD OPU）, the optical system and the collimator lens design is especially important. This paper designs an optical system and some lenses for＇the BD OPU, in...During the design process of Blu-ray disc optical pick-up （BD OPU）, the optical system and the collimator lens design is especially important. This paper designs an optical system and some lenses for＇the BD OPU, including collimator lens, beam shaping lens for laser beam shaping, and cylinder lens for signal detecting. In this OPU, we use a triplet lens to collimate the laser beam. At the same time, we build a series of assembly jigs to make sure that each lens can be put into the OPU basement properly. At last, we get the reading spot image and S-curve photo of OPU, which can be used to read Blu-ray disc （BD）.展开更多
文摘Objective:To evaluate and compare the diagnosti c value in atlantoaxial subluxation by CT three-dimensional (3D) reconstruction . Methods:3D reconstruction findings of 41 patients with atlanto axial subluxation were retrospectively analyzed, and comparisons were made among images of transverse section, multiplanar reformorting (MPR), surface shade dis play (SSD), maximum intensity project (MIP), and volume rendering (VR). Results:Of 41 patients with atlantoaxial subluxation, 31 belon ged to rotary dislocation, 5 antedislocation, and 5 hind dislocation. All the ca ses showed the dislocated joint panel of atlantoaxial articulation. Fifteen case s showed deviation of the odontoid process and 8 cases widened distance between the dens and anterior arch of the atlas. The dislocated joint panel of atlantoax ial articulation was more clearly seen with SSD-3D imaging than any other metho ds. Conclusions:Atlantoaxial subluxation can well be diagnosed by CT 3D reconstruction, in which SSD-3D imaging is optimal.
基金the project cooperated by Optical Memory National Engineering Research Center,Tsinghua University and Philips Investment Co.,Ltd.
文摘During the design process of Blu-ray disc optical pick-up （BD OPU）, the optical system and the collimator lens design is especially important. This paper designs an optical system and some lenses for＇the BD OPU, including collimator lens, beam shaping lens for laser beam shaping, and cylinder lens for signal detecting. In this OPU, we use a triplet lens to collimate the laser beam. At the same time, we build a series of assembly jigs to make sure that each lens can be put into the OPU basement properly. At last, we get the reading spot image and S-curve photo of OPU, which can be used to read Blu-ray disc （BD）.
