在兽医的应用课件

Computed tomography (CT) in veterinary medicine CT(计算机体层摄影) 在兽医医学上的应用,H. van Bree & I. Gielen,Department Medical Imaging Faculty of Veterinary Medicine Ghent University,Radiology Computed Tomography (CT),X-rays,Draw backs of conventional radiology 传统放射学回顾,Three dimensions becoming two 三维变成二维 Superposition 叠影 Distortion of the image 图像的失真 Limited soft tissue differentiation 软组织分辨率有限,CT: what? 什么是CT？,Is a form of radiography in which a beam of x-rays is directed to the patient from many different angles. 是一种X-rays，光束可以沿不同角度直接照射病人。 The fractional transmission of the x-rays through the patient is measured with electronic sensors. X-rays x-rays可以分次穿过病人，并可以用电子感受器测量。 The signals are converted to digital form + sent to a computer. 信号被转变成数字的形式，并输入电脑。,Set of Disconnected Data间断的数据设置 Series of contiguous 2-D axial images of specified thickness are required. 一系列特殊厚度的2维轴图像,Conventional CT 传统CT,Single-Slice Spiral CT 单层螺旋CT,Continuous Volume of Data数据连续 Spiral pattern of volumetric data acquired 旋转模式获得数据,“Step and Shoot” Gantry Rotation 间断照射扫描架旋转 Gantry containing x-ray tube and detectors returned to starting position after one 360-degree rotation, patient advanced fixed distance through gantry. 扫描架包括X-rays电子管和检测器，旋转360度后，再回到正常位置，因为病人先前被固定在扫描架上。.,Continuous Gantry Rotation 连续扫描架旋转 Gantry housing x-ray tube and detectors rotates uninterrupted around the patient while patient continuously advanced through gantry 当病人连续的通过扫描架时，有X-ray电子管和检测器的扫描架绕病人持续旋转。,Technological Comparison of CT Scanners CT扫描仪在技术上的对比,Comparison of Single-Slice CT and Multislice CT 单层螺旋CT与多层螺旋CT的比较,Single-Slice Spiral CT 单层螺旋CT,Multislice Spiral CT 多层螺旋CT,One Detector Row一个检测面 Radiation penetrating through patient is registered by one row of detectors 穿过病人的射线是被一排检测器记录。,Four Detector Rows四个检测面 Radiation penetrating through patient is registered by four rows of detectors 穿过病人的射线被四排检测器记录。,One Slice一层 Spiral path traced around patient yields one slice per gantry rotation 扫描架每旋转一圈，产生一层断面图像,Spatial resolution and pixel 空间（立体）的分辨和像素,CT images portray differences primarily in physical density, rather than in atomic number. CT主要是根据物理密度而不是电子数鉴别组织的差异的。 These differences can be accentuated in terms of shades of grey in the image by manipulating the window. 这些差异可通过操作窗口成像的灰色阴影而明显化,Different windows 不同的窗口,Soft tissue window: WW 400; WL 60,Bone window: WW 3500; WL 500,Advantages:优点 Avoiding superimposition of surrounding structures. 避免环绕结构形成重影 Superior tissue contrast-density difference. 优异的组织对比密度差异 Possibility of recons in different planes (2D, 3D). 对不同平面进行远程操作（2D，3D） Measurements possible (density, surface, size). 可以测量（密度，表面积，大小）,Disadvantages:缺点 Radiation hazard. 射线的危害 High cost? 高成本？ Access to equipment? 有权使用设备否？ General anaesthesia. 全身麻醉 Learning curve dealing with axial pictures. 学会处理轴线图像的曲线,(Dis)advantages of CT CT的优缺点,Radiation dose from CT CT射线的放射剂量,Data from NRPB 1992,Sagittal reconstructions 弧矢重建,CT: 2D-reconstructions CT：二维重建,CT: 3D-reconstructions CT：三维重建,CT artefacts CT误差,Most common:最常见 Streak artefacts 纹理 Partial volume artefacts 局部体积,Beam hardening 射束硬化,Why CT ? 为什么要做CT？,Any situation where superimposition should be avoided. 被检结构不受邻近器官重叠干扰,Any situation where superimposition should be avoided. 被检结构不受邻近器官重叠干扰 Any situation where the extension of a process should be evaluated. 评估病程的进展。,Why CT ? 为什么要做CT？,Any situation where superimposition should be avoided. 被检结构不受邻近器官重叠干扰 Any situation where the extension of a process should be evaluated. 无论什么情况都要评估病程进展。 CT guided biopsies. CT可以引导活组织检查。 Evaluation of treatment/follow-up. 评估治疗效果/追踪观察,Why CT ?,When CT in small animals? 小动物何时做CT？,Affections of the skull 颅部受影响 Brain 脑 Splanchnocranium 咽颅 Nasal cavity 鼻腔 Spinal problems 脊柱问题 Orthopaedics 矫形外科 Detection of fragments 碎片检测 Elbow 肘 Tarsus 跗节 Other其他,Asymmetry lat ventricles = “mass-effect” 侧脑室不对称=“肿块影响”,Contrast enhancement 对比增强,Brain pathology 脑部病理,Indications for CT CT的应用,Affections of the skull 颅部受影响 Brain脑 Splanchnocranium 咽颅 Nasal cavity鼻腔 Spinal problems脊柱问题 Orthopaedics 整形外科 Detection of fragments 碎片检测 Elbow 肘 Tarsus 跗节 Other其他,Indications for CT CT的应用,Affections of the skull 颅部受影响 Brain脑 Splanchnocranium 咽颅 Nasal cavity鼻腔 Spinal problems脊柱问题 Orthopaedics 整形外科 Detection of fragments 碎片检测 Elbow 肘 Tarsus 跗节 Other其他,CT tarsocrural OCD 分离性骨软骨炎，跗腕部骨软骨炎的CT,Distal lesion 远端损伤,Dorsal lesion 背侧损伤,Proximal lesion 近端损伤,Exact location精确定位 Size + extend尺寸+扩大 Number of fragments碎片数量,Inflammation炎症,Soft tissue swelling 软组织肿胀,Local extension of neoplasm 螯生物的局部增大,Metastases 转移灶,Follow-up 追踪观察,CT horse CT检查马,Limitations: 局限 Size 大小 Weight 体重,Indications for CT horse 马CT的应用,Skull 颅部 Dental problems 牙齿问题 Sinus problems 鼻窦问题 Etmoid problems 筛骨问题 (Brain) 脑部 Extremities 四肢 Fragments? Navicular, any body part 碎片？足舟骨炎，其他部位 Complex fractures 复合骨折,Sinusitis 鼻窦炎,Dental problems 牙齿问题,Tooth fracture 牙齿断裂,Bilateral fracture M1 Food sinus maxillaris,Indications limbs CT horse 马四肢CT的应用,Feet/distal limb (till carpus?-tarsus?): 脚/肢远端（到腕？-跗部？） fracture (spiral) 螺旋骨折 fragments 碎片 OCD 分离性骨软骨炎 sesamoids 籽骨 navicular bone 足舟骨炎 soft tissues?.软组织？,Spiral P1 fracture 螺旋状P1骨折,Spiral P1 fracture 螺旋状P1骨折,PET-CT 正电子发射计算机断层显像仪,PETCT,positron emission tomography 正电子发射计算机断层显像技术 -rays Metabolism 新陈代谢,computed tomography CT 计算机X线断层摄影术 X-rays Anatomy 解剖学,PET-CT,Localisation of Activity 定位,Image fusion 图象融合 Combined systems 复合系统 CT/MRI/SPECT: data acquired at the same scanning session: no motion! CT/MRI/SPECT: ：扫描过程中同期获得数据（无需移动） Image fusion with soft ware programs Manual-automatical人工-自动 CT, TCT: anatomical