医学影像学绪论课件

1、Medical ImagingDiagnostic ImageologyInterventional RadiologyDiagnostic RadiologyUltrasonographyNuclear ImagingDiagnosisTherapyScintigraphy学习医学影像学的注意点了解不同成像技术的基本原理及其图像特点掌握图像的观察与分析方法，了解正常影像学表现和常见病的异常表现及其病理基础掌握不同成像手段在不同疾病诊断中的作用与限度影像学检查价值很大，但有限度，需结合临床资料Diagnostic Imaging MethodsDiagnostic imaging is a d

2、ynamic specialty that has undergone rapid change with continuing advancements in technology.Not only has the number of imaging methods increased but each one continues to undergo improvement and refinement of its use in medical diagnosis.第一章 X线成像Radiography第一节 普通X线成像一 、 X线成像基本原理与设备 X线的产生，X线是真空管内高速行进

3、的电子流轰击钨靶时产生的The x-ray beam is produced by bombarding a tungsten target with an electron beam within an x-ray tube.X线的特性穿透性：与管电压和物体的密度与厚度相关荧光效应：透视的基础感光效应：摄影的基础电离效应：放射治疗的基础、X线防护X线成像基本原理As x-ray pass through the human body they are attenuated by interaction with body tissues(absorption and scatter), re

4、sulting in an image pattern recognizable as human anatomy.基本条件X线具有穿透性存在密度(density)与厚度(thick or thin)的差异显像过程二、 X线图像特点X线图像不同灰度的影像反映了人体解剖结构和病理状态的不同密度和厚度X线图像是重叠的，有一定程度的放大，并可产生伪影三、 X线检查技术Radiographic Techniques自然对比(natural contrast) 人工对比(artificial contrast)三、 X线检查技术Radiographic Techniques 普通检查透视(Fluoros

5、copy)、摄片(Plain film)特殊检查体层摄影(conventional tomography)、软线摄影(soft beam radiography)造影检查 contrast administration examination三、 X线检查技术Radiographic Techniques造影检查对比剂(contrast medium)高密度对比剂：钡剂(barium)、碘剂(iodine)等低密度对比剂：气体(gas agents)造影方式直接引入：口服、灌注、穿刺注入间接引入：经静脉注入对比剂，生理性排泄检查前准备及造影反应的处理三、 X线检查技术Radiographic

6、TechniquesX线检查方法的选择原则(principle)安全(safe)、准确(accurate)、简便(convenient)、经济(economic)四、X线诊断的临床应用成像清晰、经济、简便胸部、骨骼、胃肠道首选五、X线检查中的防护技术方面：屏蔽防护、距离防护患者方面：照射次数、范围、条件，遮盖工作人员方面：自我防护，定期体检第二节 数字化X线成像数字化X线成像（digital radiology） 1. CR（影像板，imaging plate IP) 2. DF (影像增强电视系统，IITV) 3. DR（平板探测器，flat panel detectors)Principl

7、e of CRPrinciple of DR感光度与解析度不能很好兼顾可以同时做到高感光度和高解析度第二节 数字化X线成像DR的临床应用 图像软件：Inverse Topography (组织平衡软件)Soft tissue + Bone detail at the same time动态范围宽一次曝光可通过窗宽,窗位的调整获得从软组织到骨骼不同的影像,甚至可以清楚到头发。 第三节 数字减影血管造影(Digital Subtraction Angiography, DSA)DSA成像基本原理血管造影时，由于血管与骨骼和软组织影像重叠，致使血管显影不请。将X线图像数字化，用1帧血管内不含对比剂的

8、图像作为蒙片，和1帧含对比剂的图像相减，使图片中代表骨骼和软组织的数字相抵消，只剩有对比剂的血管显影清晰。有助于诊断和做各种介入手术Principle of DSA ImagingA method for showing contrast-filled vessels without any interfering background.“Mask” image, just before the contrast medium is injected, onto which the images with contrast medium were overlaid to coincide, p

9、roducing a subtraction image only displaying the contrast-filled vessels.DSA检查技术和临床应用DSA techniques and clinical applications动脉(percutaneous arterial)DSA静脉(percutaneous venous)DSA旋转(rotate)DSA，3D立体实时成像第二章 计算机体层成像(Computed Tomography)Introduction Since its introduction in the 1970s, CT has been shown

10、 to have wide applications within all the radiological subspecialities. It has become a primary imaging technique in the clinic.第一节 CT成像基本原理与设备基本原理 用X线束对人体检查部位一定厚度的层面进行扫描，由探测器接受衰减的X线，并由光电转换器变为电信号，再由模数转换器变为数字进行计算机处理，获得该层面的每个体素的X线衰减系数，再由数模转换器把每个体素的数字转换成不等灰阶度的像数，按矩阵排列，构成CT图像What is CTCT images a sectio

11、n or slice of the patientTwo-dimensional image of the sliceReconstructed image(array of quantized gray scale values or pixels)Pixel values(CT number)are related to the linear attenuation of the corresponding volume element of the slice(voxel)CT设备( Equipment)普通CT Conventional CT螺旋CT Spiral (helical)

12、CT多层螺旋CT Multislice CT (MSCT）双源多层螺旋CT Dual Source CT (DSCT）电子束CT Electron beam CT (EBCT)平板CT Flat panel CT世界第一台双源 CTSOMATOM Definition 球管球管探测器探测器多层螺旋CT的趋势“多排和多层”1998年，8排或16排或32排探测器，实现4层扫描，2002年，24排探测器，实现16层扫描；2004年，32或64排探测器，实现64层扫描；2005年，128层扫描，双球管2006年，256层扫描，2007年，320层扫描200？年，平板探测器，1024X768扫描CT球管

13、的趋势：0.75MHU1.0MHU1.5MHU2.0MHU3.0MHU-3.5MHU4.0MHU5.3MHU6.3MHU7.5MHU.2003年SIEMENS 0MHU球管 Clinical Benefits of Multislice CTShorter Scan Time0.33sLarger VolumeClinicalApplicationIsotropic Resolution0.4mmmore detailedmore speedymore volume第二节 CT图像特点数字图像(digital imaging)矩阵(matrix)像素与体素(pixel and voxel)CT

14、值(CT pixel numbers)窗宽、窗位(window width and centre)CT value图像质量的进展.二 维 横 断 面 到 三 维 图 像 重 建第三节 CT检查技术CT Techniques平扫(plain scanning)对比增强扫描(contrast enhancement)造影扫描(other contrast methods)HRCT (high resolution computed tomography)第三节 CT检查技术CT Techniques重建技术(Reconstruction Techniques)表面遮盖法重建（Surface Sha

15、ded Display, SSD）最大密度投影（Maximum Intensity Projection, MIP）容积再现（Volume Rendering, VR）多层面重建（Multiplanar Reconstruction, MPR）曲面多层重建（Curved Multiplanar Reconstruction, CMPR）仿真内窥镜技术（Virtual Endoscopy, VE）HeadlinestenosisCourtesy of University of Erlangen, Department of Radiology and Institute of Medical

16、Physics SOMATOM Sensation 646 sec for 350 mm64 x 0.6mm (2x32)Resolution 0.4 mmRotation 0.37 sec120 kV / 150 mAs缺乏造影剂？扫描比造影剂跑得快！HeadlineEmotion 16 6.5 for 235.5mm16 x 1.2 mmPich 1.3Rotation 0.6 sec130 kV90 effective mAsCourtesy of Jiangsu Prov People Hospital / NanJin, ChinaHeadlineCourtesy of Jiangs

17、u Prov People Hospital / NanJin, ChinaEmotion 16 6.5 for 235.5mm16 x 1.2 mmPich 1.3Rotation 0.6 sec130 kV90 effective mAsHeadlineCourtesy of Jiangsu Prov People Hospital / NanJin, ChinaEmotion 16 10s for 258mm16 x 1.2 mmPich 1.2Rotation 1.0 sec130 kV90 effective mAsHeadlineCourtesy of Jiangsu Prov P

18、eople Hospital / NanJin, ChinaEmotion 16 10s for 258mm16 x 1.2 mmPich 1.2Rotation 1.0 sec130 kV90 effective mAs肺动静脉瘘（两侧）曲面重建Arteriovenous fistula of pulmonary vessels(bilateral)Aneurysm and Dissection第三节 CT检查技术CT Techniques功能(function)及其他检查灌注成像 Perfusion 骨密度测定 Quantitative CT (QCT)冠状动脉造影 CT coronary

19、 artery angiography 骨密度分析区（五点修饰轮廓）模板的水样部分模板的骨样部分 男 性, 56 岁, 症 状 后150 min 常 规 CT Time to Peak CBF 随 访 颅 内 动 脉 栓 塞 随 访 CT 显 示 液 化 灶embolism of intracranial arteries, follow-up CT image shows the infarctionmale, 56, 150min after the onset左冠状动脉钙化狭窄CT coronary artery VE扫描层厚、空间分辨率和冠脉成像SOMATOM Sensation Ca

20、rdiacCardiac MorphologyAdditional Clinical Information received from ECG-gated scan Calcified ThrombusAortic ValveECG-Gated Scan16-Slice Cardiac Function Analysis syngo Argus, CT 4D and LV-FunctionCourtesy of Grosshadern Clinic EF EDV ESV Mass Wall Thickening MovieCompatible to MRI and CT DataMCBLCA

21、小分支的动脉瘤第四节 CT诊断的临床应用优点：断层图像密度分辨率高可反映造影剂在不同时相的变化，大大扩展了临床检查范围缺点：较昂贵X线损伤第四节 CT诊断的临床应用中枢神经系统头颈部胸部心脏与血管腹部盆腔骨骼系统第三章 超声成像(ultrasonography,USG)第四章 磁共振成像（Magnetic Resonance Imaging , MRI） Imaging method using a strong magnetic field and gradient field to localize burst of radiofrequency signals coming from a

22、 system of spins consisting of reorienting hydrogen (H) nuclei(protons) after they have been disturbed by radiofrequency pulses.磁共振成像是利用体内氢原子核在强磁场内发生磁矩，用射频发生共振提供能量，改变磁矩；停止射频，恢复磁矩，释放能量，产生信号，经计算机处理，形成MR图像。 成 像 基 本 原 理纵向磁化（longitudinal magnetization）纵向磁化减小与横向（transverse）磁化驰豫与弛豫时间（relaxation time）驰豫时间与M

23、RI成像脉冲序列（pulse sequence）与加权像（weighted imaging， WI）T1加权像（T1WI）： 短TE, 短TRT2加权像（T2WI）： 长TE, 长TR MRI 设 备（MRI Equipment） Low field MR， open system MRRecent progress in MRI unitPolarization of magnetic fieldSpecial MR UnitFaster and stronger magnetic resonance gradientsRF coil RF CoilsAdvanced Imaging Tec

24、hniquesWhole body MR screening It is an ideal modality for the purposes of healthcare screening that has both high sensitivity and specificity with out radiation hazard. The true benefit of whole body MR imaging is in the variety of disease found. Its value is in its reliability and accuracyPatient

25、with PlasmocytomaTSE T1+2w, PAT 2Schlemmer, Claussen et al.University Tuebingen (Germany)Neuro-Ocular Plane ImagingImage courtesy of Dr Scarabino, Casa Sollievo della Sofferenza, Italy.3T Imaging Resembles SpecimenMRI 图 像 特 点MRI characteristics多参数成像（multiple sequences）多方位成像流动效应对比增强MRI 图 像 特 点MRI cha

26、racteristics多参数成像多方位成像（provide images in any anatomic plane）。现在有挑战。流动效应对比增强MRI 图 像 特 点MRI characteristics多参数成像多方位成像流动效应（flowing effects）对比增强3D ToFTR/ TE 35 /3.6 ms, 192x512,SL 0.8 mm,108 partitionsTA: 6:44 minHigh-Resolution ToF at 3TMRI 图 像 特 点MRI characteristics多参数成像多方位成像流动效应对比增强(contrast enhancem

27、ent)MRI增强扫描的适应症 application of MRI enhancement肿瘤的鉴别与定性(tumor)血脑屏障是否破坏(blood-brain barrier)提高病变的发现率(more sensitive)MRI造影剂(contrast medium)主要分为两类：顺磁性物质(Gd-DTPA) paramagnetic contrast medium超顺磁性物质(AMI-25,菲力磁) superparamagnetic contrast medium转移瘤T1C+，T2肝Ca(CT,T1,T2FS,T1C+) MRI检查技术 MRI Techniques脉冲序列（pul

28、se sequence）SE序列，梯度回波（gradient echo）序列，回波平面成像（echo-planar image，EPI）脂肪抑制（fat suppression）MRC （Cinema）MRI对比增强（contrast enhancement）MRA(MR血管造影)MRI水成像(MRCP, MRU, MRM)功能性MRI成像（fMRI）MRSDWIMRI检查应注意的问题禁忌证（contraindication）： 起搏器（pacemaker） 动脉瘤金属夹（aneurysm clips） 眼球金属异物（intraocular metallic foreign bodies） 危

29、重患者（serious patient）相对禁忌证：人工关节、体内金属异物、高热患者、早期妊娠等检查前注意事项Advantage and Disadvantage of MRIAdvantage：Multiple tomographical imageMore information from imagingHigh soft tissue resolutionContrast enhancement have wide applicationsDisadvantage：ExpensiveComplicationMore contraindication第四节 MRI诊断的临床应用中枢神经系统

30、头颈部循环系统肌骨系统盆腔胸部腹部分子影像学Molecular imagingThough evolving continuously, the field of molecular imaging is expected to bring radiology into the forefront of disease diagnosis and therapy design through advances in three modalities: radionuclide, MR, and optical imaging. Molecular imagingPET/SPECTCT perfu