医学交流课件：腹部超声 －物理

1、ABDOMEN- Physics 腹部超声腹部超声 物理物理 OPTIMIZING YOUR MACHINE 优化你的仪器 OPTIMIZING YOUR MACHINE 优化你的仪器优化你的仪器 Ultrasound is a dynamic process 超声是动态的 Constant interaction between you and your machine is required 这要求你和仪器不停 的相互影响 TRANSDUCERS 探头探头 IDEAL TYPE OF TRANSDUCER? 最理想的探头？ Mechanical vs electronic 机械的和电子的

2、Linear, convex, phased array, sector scanner 线阵，凸阵，相控阵，扇扫 Scan head shape 探头的形状 Frequency 频率 Depends on use and available money! 根据用途和资金选择！ Mechanical Sector Transducer 机械的扇扫探头机械的扇扫探头 Does not allow variable focussing 没有可变的焦点 Elements are mechanically rotated 晶片是机械性转动的 Small footprint intercostal sc

3、anning 接触面小可用于肋间 Moving parts subject to wear 可戴上其它部件？ More prone to damage when dropped 掉在地上更容易坏 Electronic Transducers 电子探头电子探头 Multiple crystals fire together or sequentially 多个晶片同时或按顺序的发出声波 Multi-element transducers are called arrays 多晶片探头被称作阵 Linear 线阵 Convex 凸阵 Phased 相控阵 Linear Array Transduc

4、er 线阵探头线阵探头 Rectangular FOV 矩形的视野 Often limited skin contact 常受皮肤的接触面限制 Wide near-field, limited depth 更宽的近场视野，但深度不深 Best for musculoskeletal application, superficial structures 最好用于肌肉与骨骼，浅表的结构 Highest lateral resolution 侧向分辩率最高 High frequencies (up to 25mHz) 高频率（可达25mHz ） Convex Array Transducer 凸阵

5、探头凸阵探头 = curvilinear 60, 90, 120 等于弧线60, 90, 120 Wide near-field 近场视野宽 Even wider far-field 远场视野也宽 Best for abdominal scans 最适合腹腔检查 Phased Array Transducer 相控阵探头相控阵探头 Sector FOV 扇形的视野 Firing of multiple transducer elements in a precise sequence electronically 能电子地由多个晶片 的按顺序发出声波 Wide FOV at deep dept

6、hs 远场深部视野宽 Phased Array Transducer 相控阵探头相控阵探头 Limited near-field visibility compared with linear-array or curvilinear-array transducers 与线阵或凸阵探头相比近场视野 受限 Useful for evaluation of deeper structures 可用于检查深部结构 Best for heart (intercostal windows) 最适合用于心脏（肋间） Transducer Care 探头保养探头保养 Do not apply alcoho

7、l directly onto surface 不要在探头表面上直接用酒精 Clean/wipe after every scan 每次检查后都要清洁/擦 Freeze image when not in use 不用时要冻结图像 Heat sensitive do not sterilize 不耐热不要灭菌 Settings Power 设置功率设置功率 Intensity (Amplitude) of sound 声的强度（振幅） Adjusting power effects entire screen 调整整个屏幕的功率 Related to artefact production 与

8、伪影的产生有关 The lower the power setting, the less likely artefacts will occur 功率越低，越少产生伪影 Settings Gain 设置增益设置增益 Amplification and reject controls 控制接收回声的扩增或减少 Intensity of sound decreases with depth 声的强度随深度加深而减弱 Amplification of returning echoes 扩增回声的接收 Selects gain (vs Overall Gain) 选择增益（和总增益） Not equ

9、al to power 与功率不同 Settings Gain 设置增益设置增益 Overall Gain 总增益 Uniform amplification of all returning echoes regardless of depth 不管其深度多少，使所有接收的回声同时增强 Settings Gain 设置增益设置增益 Time Gain 时间增益 Echoes returning from deeper structures are weaker than those arising from more superficial structures 从深部结构返回的回声比浅表结

10、构返回的要弱 Selective gain 选择性增益 Near-field gain 近场增益 Far-field gain 远场增益 Series of sliding controls 一列滑动的控制键 Settings Gain 设置增益设置增益 Time Gain 时间增益 Settings Focus 设置焦点设置焦点 Set continuously during scanning, dynamic process 在动态的检查中可不停的设置 Autofocus 自动对焦 Single or multiple 单个或多个 Changes in frame rate 改变帧率 Patient Preparation 动物准备动物准备 Starve or not? 要不要禁食？ Access to water 有水源 Avoid stress aer