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1 Nuclear Medicine Imaging 核醫影像原理與處理 Imaging I 蕭穎聰 Ing-Tsung Hsiao Department of Medical Imaging and Radiological Sciences Chang-Gung University Tao-Yuan, Taiwan Imaging II Imaging III Imaging System I Imaging System II 1

Radiological Sciences Chang-Gung University Tao-Yuan,

2 核子醫學影像什麼是核子醫學影像?? 基本放射物理訊號? Radiation, isotope, density 如何偵測? detecting system (detector, scanner) 如何處理偵測資料? physical effects correction, reconstruction 如何處理與分析影像? segmentation, registration, kinetic model,.. 如何利用影像? diagnosis, planning, staging, new drug development 核子醫學影像 Planar Imaging 基本放射物理藥物注射訊號偵測影像重建影像處理分析核醫藥物研發偵測硬體研發電腦軟體處理診斷治療 PET Images Tomographic Images MRI SPECT PET 2

segmentation, registration, kinetic model,.. 如何利用影像?

3 Nuclear Medicine Imaging Nuclear Medicine : Basic Physics Tomographic Imaging PET: Basic Physics Hardware detectors, Radiopharmaecuticals Software Image Formation Reconstruction Atomic structure Physics I The Nucleus of An Atom Proton and Neutron Binding energy: MeV Radioactivity ( 放射性 ) Radioactive decay 不穩定原子核放射出輻射粒子或能量 (photons,, or gamma rays) 變成穩定狀態包括衰變,, 衰變,, 放射能量 gamma ( ) ) emission ( 伽瑪射線 or 光子 ) Nuclear binding force Positron Decay( + 正子衰變 ) Too many protons: P N+ P + + : positive beta particle or positive electron or anti-electron 正子與電子發生互毀, 產生 180 度相反方向的兩個光子 Gamma Emission ( 伽瑪射線 ) Too much energy: energy ( ) gamma ray A A gamma ray is a photon ( 光子 )(energy). A A gamma ray photon is different from the X-rayX photon only by its energy Excited nucleus 3

放射能量 gamma ( ) ) emission ( 伽瑪射線 or 光子 ) Nuclear binding force Positron Decay( + 正子衰變 ) Too many protons: P N+ P + + : positive beta particle or positive electron or anti-electron 正子與電子

4 能量傳輸光電效應, 康普敦散射, 與成對效應輻射與物質的作用 (Non-)Penetrating Radiation Penetrating or not energy Gamma ray and X-rayX are penetrating radiation History 1895: Rontgen X-rays 1896: Bequerel radiation from Uranium 1898: Curies radioactivity, Radium 1913: Georg de Hevesy tracer approach 1923: first study on biologic system 1927: Blumgart and Weiss first human study using tracer 1930s: Lawrence cyclotron 1951: Benedict Cassen: rectilinear scanner 1958: Hal Anger: Anger camera 1960s: major use 131 I 1964: Paul Harper: 99m Tc major turning point for NM 1963: Cormack CT math 1972: Hounsfield CT scanner 1970s: Phelps et al PET; Kuhl et al SPECT 核醫影像核醫影像核醫影像 = 藥物分佈的情形生理或功能性 Physiology / Metabolism Planar vs. Tomography Two Modalities: SPECT (Single Photon Emission Computed Tomography) PET (Positron Emission Tomography) Function vs. Anatomy (MRI/CT) Inject Radioactive Tracer Localizes in ROI Emits gamma-rays (photons) Tracer Concentration physiological function 平面造影 Planar Imaging 平面造影空間資訊重疊了 ==> 需要每一個空間位置的資訊 4

Lawrence cyclotron 1951: Benedict Cassen: rectilinear scanner 1958: Hal Anger: Anger camera 1960s: major use 131 I 1964: Paul Harper: 99m Tc major turning point for NM 1963: Cormack CT math 1972:

5 核醫硬體偵測系統 Standard Nuclear Medicine Imaging system Rectilinear Scanner First nuclear medicine images: thyroid 131 I scans (Back to History) 偵測系統 - 伽瑪攝影機 First gamma camera (1958) 核醫硬體偵測系統 Standard Nuclear Medicine Imaging system 電腦斷層掃瞄 Computed Tomography Tomography cross-sectional imaging Emission Computed Tomography (ECT) Compute cross-sectional tracer distribution Collect data at all angles 1-D projection=>2d sinogram Sinogram -----> cross-sectional distribution where -----> reconstruction t sinogram 5

Computed Tomography Tomography cross-sectional imaging Emission Computed Tomography (ECT) Compute cross-sectional tracer distribution

6 Sinogram Nuclear Medicine Imaging Two Modalities: SPECT: (Single Photon Emission Computed Tomography) Physical Mechanism: 2. PET:(Positron Emission Tomography) Physical Mechanism: Radio-isotopes 99m Tc, I, Tl Radio-isotopes 15 O, 11 C, F 18 Emission Computed Tomography II Simple Illustrations of Cameras Emission Computed Tomography III Example of Real Detectors SPECT Detectors :Picker Irix PET Detectors :GE Advance Whole Body PET SPECT 單光子電腦斷層掃瞄 PET 6

PET:(Positron Emission Tomography) Physical Mechanism: 90 45 0 Radio-isotopes 99m 123 201 Tc, I, Tl Radio-isotopes 15 O,

7 Nuclear Medicine Imaging Nuclear Medicine : PET and SPECT Tomographic Imaging PET: Basic Physics Hardware detectors, Radiopharmaecuticals Software Image Formation Reconstruction Clinical Application New Development Positron Detection Coincidence Two Photons detected at the same time (timing circuit) i j Nuclear Medicine Imaging Nuclear Medicine : PET and SPECT Tomographic Imaging PET: Basic Physics Hardware detectors, Radiopharmaecuticals Software Image Formation Reconstruction Clinical Application New Development PET Scanner 正子掃瞄儀 Block Detectors In PET, block detectors are arranged in rings Nuclear Medicine Imaging Nuclear Medicine : PET and SPECT Tomographic Imaging PET: Basic Physics Hardware detectors, Radiopharmaecuticals Software Image Formation Reconstruction Clinical Application New Development 7

8 Sinogram Tomographic Reconstruction 2D object sinogram 影像重建解 Ax=b 的問題? Analytical Reconstruction Reconstruct object from projection data g A x b xˆ Tomographic System -1 A Reconstruction The Most popular reconstruction method: FBP: filtered backprojection algorithm Ax b ˆ 1 x A b Iterative algorithm: k ˆ g Statistical Reconstruction Optimization Algorithm System Model Η O Reconstruction Update Parameter ˆ 1 k ( g) log Pr( g ) Criteria? Satisfy Yes arg max ( g)? No *ˆ Done FBP FBP vs. Statistical Reconstruction *ˆ k ˆ 2ˆ 1ˆ Statistical 0ˆ 8

reconstruction method: FBP: filtered backprojection algorithm Ax b ˆ 1 x A b Iterative algorithm: k ˆ g Statistical Reconstruction

9 PET Processing Examples Nuclear Medicine Imaging Nuclear Medicine : PET and SPECT Tomographic Imaging PET: Basic Physics Hardware detectors, Radiopharmaecuticals Software Image Formation Reconstruction Clinical Application New Development New Development Dual Modality: PET/CT Function + Anatomy + = + = Function (PET) Anatomy (CT) Dual Modality: PET/CT Thanks Other Dual Modalities SPECT/CT, SPECT/MRI, PET/MRI, Optical Imaging/PET 9

Application New Development New Development Dual Modality: PET/CT Function + Anatomy + = + = Function (PET)

10 分子影像 :Molecular Imaging PET and SPECT for molecular imaging in living subjects: High sensitivity, full quantitative tomography Animal Imaging MicroPET, MicroSPECT for small animal imaging In Vivo Studies: 18 FDG Mouse Heart 核醫影像處理 Weight: 32 g Injection: 0.58 mci Uptake: 120 minutes 核醫影像處理核醫影像處理影像融合 Image processing: max the info from an image using computer Including: Basic processing: edge/contrast enhancement Pre-processing before reconstruction System artifact correction Kinetic analysis (time analysis) 3D visualization Image Fusion with other modalities PACS.. 10

58 mci Uptake: 120 minutes 核醫影像處理核醫影像處理影像融合 Image processing: max the info from an image using computer Including: Basic processing:

11 核醫影像處理藥物動力學 FIG. 3. Distribution of FDG in cross section (OM + 8 cm ) of normal human brain at various times following intravenous injection of FDG bolus. Distributions were measured and reconstructed with ECAT. At early times, F-DOPA PETdistribution dynamic reflects image boththru LCRMGlc the same and slice cerebral blood flow (CBF), with effects of CBF gradually diminishing with time. After 20 min, distribution becomes stable. Photographic gray scales in these distributions of different times are not normalized to a common reference. Although, relative distribution in brain remains stable, absolute amount of FDG dose change slowly as shown in Fig. 4. Distributions shown are selected from a total of distributions obtained for each study. 核醫影像處理其他影像分割影像參數最佳化影像 ( 系統 ) 品質評估什麼是核子醫學影像?? 11

At early times, F-DOPA PETdistribution dynamic reflects image boththru LCRMGlc the same and slice cerebral blood flow (CBF), with effects of CBF gradually diminishing with time.

第二組掃描器規範書

第二組掃描器規範書第二組掃描器規範書 1. A4 規格 2400 DPI( 含 ) 以上掃描器第 1 項 ) 1-1. 機型 : 平台式掃瞄器 1-2. 光學解析度 :2400x2400DPI( 含 ) 以上 1-3. 最大輸出解析度 :9600DPI( 含 ) 以上 1-4. 介面 :SCSI 介面 ( 附介面卡及傳輸線 ) 或 USB