影像学-CT2课件.ppt

Reconstruction Idea Algebraic Reconstruction Technique(ART) First Generation Second Generation Third Generation Fourth Generation Third Fourth Generations E-Beam CT Scanner Spiral/Helical Scanning Spiral CT Scanner Spiral CT Scanner Data Acquisition System (DAS) Data Acquisition System (DAS) Gantry Data acquisition system Table Computer Parallel processors Control console Storage units Tapes, disks Recording device Network interface X-ray generator Heat exchanger (From Elscint) Gantry Data acquisition system Detectors Storage units: Tapes, disks Display Control console Computer Parallel processor Table Recording Source Network Filter Source Detector Pre-Collimator Post-Collimator Patient Scattering (From G. Wang) X-ray Tube Detectors CT Gantry(From Siemens) Filter Source Detector (From G. Wang) 演示DrawSpiral * * 伦琴因发现X射线获得 首届诺贝尔物理学奖。 1901???????伦琴 (Roentgen) 发现X射线(1895) 1914???????劳厄（Laue） 晶体的X射线衍射 1915???????布拉格父子 (Bragg) 分析晶体结构 1917 巴克拉 (Barkla) 发现元素的标识X射线 1924????????塞格巴恩 (Siegbahn ) X射线光谱学 1927????????康普顿(Compton等六人) 康普顿效应 1936????????德拜 (Debye) 化学 1946????????马勒 (Muller) 医学 1962 沃生(Wason等三人) 医学 1964????????霍奇金 (Hodgkin) 化学 1979????????柯马克和豪森菲尔德（Cormack/Hounsfield） 医学 1981 塞格巴恩(Siegbahn) 物理 同X射线有关的诺贝尔奖 正片与负片 防护 防护 洛书 九宫图，幻方 洛书 九宫图，幻方 河出图,洛出书,圣人则之 ---易?系辞 伏羲时代,黄河中有龙马背负河图. 夏禹时代,洛水中有神龟背负洛书. 洛书 九宫图，幻方 洛书 九宫图，幻方 x1 x2 x3 x6 x5 x4 x9 x8 x7 已经数字化 ??=4 ?2=3 ?3=2 ?4=1 (From G. Wang) 3 2 3 2 4 3 2 1 0 0 0 0 4 3 2 1 6 4 -2 2 Update a guessbased ondata differences Guess 1 Guess 0 Guess 2 Error Error (From G. Wang) 洛书 九宫图，幻方 8 1 6 7 2 9 5 4 3 洛书 九宫图，幻方 稀疏矩阵 比较图像恢复与图像重建 融会贯通 洛书 九宫图，幻方 8 1 6 7 2 9 5 4 3 多个解 演示Matlab One detector Translation-rotation Parallel-beam (From G. Wang) Multiple detectors Translation-rotation Small fan-beam (From G. Wang) Multiple detectors Translation-rotation Large fan-beam (From G. Wang) Detector ring Source-rotation Large fan-beam 演示csim 重建算法 (From G. Wang) (From Picker) (From Siemens) Speed: 50,