彩超中pw与cw的区别

admin

                    

                    

                    
                    
                    <p><img src="http://mmbiz.qpic.cn/mmbiz/M2H0aGBjWUTRia7nqkArYeKZUqEfdmpNibMPiaZk4gvlWk5v5lUKyXhjJP4CENKQeQt5HI8zwcTCWJOkicfWJiatdJQ/640?wx_fmt=gif" data-type="gif" class="" data-ratio="0.10555555555555556" data-w="720"  /></p><p><span style="font-size: 14px;"></span></p><p style="line-height: 2em;margin-bottom: 5px;"><span style="font-size: 14px;">脉冲式多普勒（pw）和连续式多普勒（cw）各自有其特点，介绍如下：</span></p><p style="line-height: 2em;margin-bottom: 5px;"><span style="color: rgb(2, 30, 170);font-size: 14px;"><strong>脉冲式多普勒：</strong></span></p><p style="line-height: 2em;margin-bottom: 5px;"><span style="font-size: 14px;">其发射与接收的超声波均为间断脉冲式，显示声束上某一深度的血流速度、方向和性质。</span></p><p style="line-height: 2em;margin-bottom: 5px;"><span style="font-size: 14px;"><strong>优点：</strong>有距离分辨能力，可定点测定心血管内某一小块区域（取样线）的瞬时血流频谱，因此可定位异常血流，并可鉴别正、异常血流。</span></p><p style="line-height: 2em;margin-bottom: 5px;"><span style="font-size: 14px;"><strong>缺点：</strong>易受尼奎斯特频率的影响，若流速超过最大显示频率，则在频谱上出现频谱混叠现象，因此不能定量测定高速血流。</span></p><p style="line-height: 2em;margin-bottom: 5px;"><span style="font-size: 14px;"><strong><span style="font-size: 14px;color: rgb(2, 30, 170);">连续式多普勒：</span></strong></span></p><p style="line-height: 2em;margin-bottom: 5px;"><span style="font-size: 14px;">其发射与接收的超声波均为连续性，是整个声束通道上全部血流信号的总和。</span></p><p style="line-height: 2em;margin-bottom: 5px;"><span style="font-size: 14px;"><strong>优点：</strong>速度分辨率强，其频谱可反映高速血流的速度，而不受尼奎斯特频率的影响。</span></p><p style="line-height: 2em;margin-bottom: 5px;"><span style="font-size: 14px;"><strong>缺点：</strong>无距离选通性能，缺乏距离分辨力，声束所经的途径各点信息重叠，被探头同时接收，从而使得输出信号无法定位。</span></p><p style="line-height: 2em;margin-bottom: 5px;"><span style="color: rgb(2, 30, 170);font-size: 14px;"><strong>频谱分析包括：</strong></span></p><p style="line-height: 2em;margin-bottom: 5px;"><span style="font-size: 14px;"><strong>（1）频移时相</strong>：即收缩期、舒张期或全心动周期，以频谱的横坐标（X轴）的数值代表时间，单位为每秒。</span></p><p style="line-height: 2em;margin-bottom: 5px;"><span style="font-size: 14px;"><strong>（2）频移幅值</strong>：以频谱的纵坐标（Y轴）的数值代表血流速度的大小，单位为kHz或cm/s和m/s，测定血流速度，包括最大流速、平均流速、加速度和减速度；计算跨瓣压差；测定加速度、减速度时间、射血前期、射血时间及压力降半时间。</span></p><p style="line-height: 2em;margin-bottom: 5px;"><span style="font-size: 14px;"><strong>（3）频移方向</strong>：以频谱的基线为准，基线上方频移为正值（正向），表示血流方向朝向探头；基线下方频移为负值（负向），表示血流方向背离探头。</span></p><p style="line-height: 2em;margin-bottom: 5px;"><span style="font-size: 14px;"><strong>（4）频谱辉度</strong>：以亮度表示，反映取样容积或探查声束内具有相同流速的红细胞相对数量的多少。速度相同的红细胞数量越多，散射信号强度越大，频谱辉度也就越亮，反之，辉度弱（暗）。</span></p><p style="line-height: 2em;margin-bottom: 5px;"><span style="font-size: 14px;"><strong>（5）频谱的离散度</strong>：以频谱在垂直方向上的宽度表示，指某一瞬间取样容积或探查声束内红细胞速度分布范围的大小。红细胞速度分布范围大，则频谱宽，反之，频谱窄，频谱宽度是识别血流动力学改变的重要因素。</span></p><p style="line-height: 2em;margin-bottom: 5px;"><span style="font-size: 14px;">层流显示频谱窄，光点密集，频谱包络较光滑，血流频谱和基线之间常呈现空窗；湍流显示频谱宽，光点疏散，频谱包络毛糙，血流频谱和基线之间为充填状；涡流时，因红细胞运动呈多方向性，因而其特征为双向湍流频谱。</span></p><p style="line-height: 2em;margin-bottom: 5px;"><span style="font-size: 14px;">由以上几项分析可得出以下四项异常，具有临床意义：</span></p><p style="line-height: 2em;margin-bottom: 5px;"><span style="font-size: 14px;">（1）血流速度异常：指所测流速高于或低于正常范围。</span></p><p style="line-height: 2em;margin-bottom: 5px;"><span style="font-size: 14px;">（2）血流时相异常：指血流的持续时间长于或短于正常范围。</span></p><p style="line-height: 2em;margin-bottom: 5px;"><span style="font-size: 14px;">（3）血流性质异常：指血流由正常的层流变为湍流。</span></p><p style="line-height: 2em;margin-bottom: 5px;"><span style="font-size: 14px;">（4）血流途径异常：指血流出现在正常人心脏中不应出现的通道，如间隔缺损、异常通道及返流等。</span></p><p><img class="" data-backh="380" data-backw="559" data-copyright="0" data-ratio="0.680921052631579" data-s="300,640" src="http://mmbiz.qpic.cn/mmbiz_jpg/dx3KibwtDhvfMusfnIibpCibDQ9MaXhjETP8OicscYTEuAD85jgsAo91wlPSsBgNiaAAGOqP7aIJIRO61yM4iaOKT2nA/640?wx_fmt=jpeg" data-type="jpeg" data-w="608" style="width: 100%;height: auto;"  /></p><p><span style="font-size: 14px;"></span></p><p style="max-width: 100%;min-height: 1em;color: rgb(51, 51, 51);text-align: right;"><span style="max-width: 100%;font-size: 12px;box-sizing: border-box !important;word-wrap: break-word !important;">来源：网络</span><br style="max-width: 100%;box-sizing: border-box !important;word-wrap: break-word !important;"  /></p><p style="max-width: 100%;min-height: 1em;color: rgb(51, 51, 51);"><span style="max-width: 100%;font-size: 12px;box-sizing: border-box !important;word-wrap: break-word !important;"><br style="max-width: 100%;box-sizing: border-box !important;word-wrap: break-word !important;"  /></span></p><p style="max-width: 100%;min-height: 1em;color: rgb(51, 51, 51);"><span style="max-width: 100%;font-size: 12px;box-sizing: border-box !important;word-wrap: break-word !important;"></span></p><p style="max-width: 100%;min-height: 1em;letter-spacing: 0.544px;white-space: normal;color: rgb(62, 62, 62);font-size: 16px;line-height: 25.6px;text-align: center;font-family: 微软雅黑;background-color: rgb(255, 255, 255);box-sizing: border-box !important;word-wrap: break-word !important;">赞<span style="max-width: 100%;line-height: 25px;box-sizing: border-box !important;word-wrap: break-word !important;">是一种友谊 |&nbsp;</span><span style="max-width: 100%;line-height: 25px;color: rgb(192, 0, 0);box-sizing: border-box !important;word-wrap: break-word !important;"><strong style="max-width: 100%;box-sizing: border-box !important;word-wrap: break-word !important;">分享</strong></span><span style="max-width: 100%;line-height: 25px;box-sizing: border-box !important;word-wrap: break-word !important;">传递智慧</span></p><p style="max-width: 100%;min-height: 1em;letter-spacing: 0.544px;white-space: normal;color: rgb(62, 62, 62);font-size: 16px;line-height: 25.6px;text-align: center;font-family: 微软雅黑;background-color: rgb(255, 255, 255);box-sizing: border-box !important;word-wrap: break-word !important;"><strong style="max-width: 100%;letter-spacing: 0.5px;line-height: 28px;box-sizing: border-box !important;word-wrap: break-word !important;"><span style="max-width: 100%;font-size: 15px;box-sizing: border-box !important;word-wrap: break-word !important;"><strong style="max-width: 100%;letter-spacing: 1px;line-height: 25.6px;white-space: pre;color: rgb(68, 68, 68);font-family: 宋体;box-sizing: border-box !important;word-wrap: break-word !important;"><strong style="max-width: 100%;box-sizing: border-box !important;word-wrap: break-word !important;"><strong style="max-width: 100%;color: rgb(95, 73, 122);font-size: 14px;line-height: 24.381px;text-align: justify;box-sizing: border-box !important;word-wrap: break-word !important;"><span style="max-width: 100%;font-size: 18px;color: rgb(62, 62, 62);line-height: 25px;text-align: center;box-sizing: border-box !important;word-wrap: break-word !important;"><strong style="max-width: 100%;white-space: normal;font-family: 微软雅黑;color: rgb(171, 25, 66);box-sizing: border-box !important;word-wrap: break-word !important;"></strong></span></strong></strong></strong></span></strong></p><p style="max-width: 100%;min-height: 1em;letter-spacing: 0.544px;white-space: normal;color: rgb(62, 62, 62);font-size: 16px;line-height: 25.6px;text-align: center;font-family: 微软雅黑;background-color: rgb(255, 255, 255);box-sizing: border-box !important;word-wrap: break-word !important;"><strong style="max-width: 100%;letter-spacing: 0.5px;line-height: 28px;box-sizing: border-box !important;word-wrap: break-word !important;"><span style="max-width: 100%;font-size: 15px;box-sizing: border-box !important;word-wrap: break-word !important;"><strong style="max-width: 100%;letter-spacing: 1px;line-height: 25.6px;white-space: pre;color: rgb(68, 68, 68);font-family: 宋体;box-sizing: border-box !important;word-wrap: break-word !important;"><strong style="max-width: 100%;box-sizing: border-box !important;word-wrap: break-word !important;"><strong style="max-width: 100%;color: rgb(95, 73, 122);font-size: 14px;line-height: 24.381px;text-align: justify;box-sizing: border-box !important;word-wrap: break-word !important;"><span style="max-width: 100%;font-size: 18px;color: rgb(62, 62, 62);line-height: 25px;text-align: center;box-sizing: border-box !important;word-wrap: break-word !important;"><strong style="max-width: 100%;white-space: normal;font-family: 微软雅黑;color: rgb(171, 25, 66);box-sizing: border-box !important;word-wrap: break-word !important;">，您身边专业超声维修专家</strong></span></strong></strong></strong></span></strong></p><p style="max-width: 100%;min-height: 1em;letter-spacing: 0.544px;white-space: normal;color: rgb(62, 62, 62);font-size: 16px;line-height: 25.6px;text-align: center;font-family: 微软雅黑;background-color: rgb(255, 255, 255);box-sizing: border-box !important;word-wrap: break-word !important;"><strong style="max-width: 100%;letter-spacing: 0.5px;line-height: 28px;box-sizing: border-box !important;word-wrap: break-word !important;"><span style="max-width: 100%;font-size: 15px;box-sizing: border-box !important;word-wrap: break-word !important;"><strong style="max-width: 100%;letter-spacing: 1px;line-height: 25.6px;white-space: pre;color: rgb(68, 68, 68);font-family: 宋体;box-sizing: border-box !important;word-wrap: break-word !important;"><strong style="max-width: 100%;box-sizing: border-box !important;word-wrap: break-word !important;"><strong style="max-width: 100%;color: rgb(95, 73, 122);font-size: 14px;line-height: 24.381px;text-align: justify;box-sizing: border-box !important;word-wrap: break-word !important;"><span style="max-width: 100%;font-size: 18px;color: rgb(62, 62, 62);line-height: 25px;text-align: center;box-sizing: border-box !important;word-wrap: break-word !important;"><strong style="max-width: 100%;white-space: normal;font-family: 微软雅黑;color: rgb(171, 25, 66);box-sizing: border-box !important;word-wrap: break-word !important;"><span style="max-width: 100%;color: rgb(62, 62, 62);font-size: 15px;line-height: 24px;box-sizing: border-box !important;word-wrap: break-word !important;">超声一站式服务商</span></strong></span></strong></strong></strong></span></strong></p><p style="max-width: 100%;min-height: 1em;letter-spacing: 0.544px;white-space: normal;color: rgb(62, 62, 62);font-size: 16px;line-height: 25.6px;font-family: 微软雅黑;background-color: rgb(255, 255, 255);box-sizing: border-box !important;word-wrap: break-word !important;"><span style="max-width: 100%;font-size: 14px;text-indent: 0em;font-family: Arial, Verdana, sans-serif;line-height: 1.75em;box-sizing: border-box !important;word-wrap: break-word !important;">地址：广州市天河区银利街银利茶叶博览中心E栋4楼E4030室 &nbsp; &nbsp; &nbsp;</span></p><p style="max-width: 100%;min-height: 1em;letter-spacing: 0.544px;text-indent: 0em;white-space: normal;color: rgb(62, 62, 62);font-size: 12px;font-family: Arial, Verdana, sans-serif;line-height: 1.75em;background-color: rgb(255, 255, 255);box-sizing: border-box !important;word-wrap: break-word !important;"><span style="max-width: 100%;font-size: 14px;line-height: 1.75em;box-sizing: border-box !important;word-wrap: break-word !important;">邮编：510507</span></p><p style="max-width: 100%;min-height: 1em;letter-spacing: 0.544px;text-indent: 0em;white-space: normal;color: rgb(62, 62, 62);font-size: 12px;font-family: Arial, Verdana, sans-serif;line-height: 1.75em;background-color: rgb(255, 255, 255);box-sizing: border-box !important;word-wrap: break-word !important;"><span style="max-width: 100%;font-size: 14px;box-sizing: border-box !important;word-wrap: break-word !important;">电话：(+86)020-8722 8723 &nbsp; &nbsp;8764 5360 &nbsp; &nbsp;</span></p><p style="max-width: 100%;min-height: 1em;letter-spacing: 0.544px;text-indent: 0em;white-space: normal;color: rgb(62, 62, 62);font-size: 12px;font-family: Arial, Verdana, sans-serif;line-height: 1.75em;background-color: rgb(255, 255, 255);box-sizing: border-box !important;word-wrap: break-word !important;"><span style="max-width: 100%;font-size: 14px;box-sizing: border-box !important;word-wrap: break-word !important;">传真：020-8722 8623</span></p><p style="max-width: 100%;min-height: 1em;letter-spacing: 0.544px;text-indent: 0em;white-space: normal;color: rgb(62, 62, 62);font-size: 12px;font-family: Arial, Verdana, sans-serif;line-height: 1.75em;background-color: rgb(255, 255, 255);box-sizing: border-box !important;word-wrap: break-word !important;"><span style="max-width: 100%;font-size: 14px;box-sizing: border-box !important;word-wrap: break-word !important;">全国统一免费服务热线：400-020-6788</span></p><p style="max-width: 100%;min-height: 1em;letter-spacing: 0.544px;text-indent: 0em;white-space: normal;color: rgb(62, 62, 62);font-size: 12px;font-family: Arial, Verdana, sans-serif;line-height: 1.75em;background-color: rgb(255, 255, 255);box-sizing: border-box !important;word-wrap: break-word !important;"><span style="max-width: 100%;line-height: 24.381px;box-sizing: border-box !important;word-wrap: break-word !important;">公司官网：http://www.parts-ultrasound.com/</span><span style="max-width: 100%;font-size: 14px;box-sizing: border-box !important;word-wrap: break-word !important;"></span></p><p style="max-width: 100%;min-height: 1em;letter-spacing: 0.544px;white-space: normal;color: rgb(62, 62, 62);font-size: 16px;font-family: 微软雅黑;line-height: 24.381px;background-color: rgb(255, 255, 255);box-sizing: border-box !important;word-wrap: break-word !important;"><span style="max-width: 100%;line-height: 1.75em;text-indent: 0em;font-size: 14px;font-family: Arial, Verdana, sans-serif;box-sizing: border-box !important;word-wrap: break-word !important;">微信公众帐号：</span></p><p style="max-width: 100%;min-height: 1em;letter-spacing: 0.544px;white-space: normal;color: rgb(62, 62, 62);font-size: 16px;line-height: 25.6px;text-align: center;font-family: 微软雅黑;background-color: rgb(255, 255, 255);box-sizing: border-box !important;word-wrap: break-word !important;"><img class="" data-ratio="1" data-s="300,640" src="http://mmbiz.qpic.cn/mmbiz_jpg/dx3KibwtDhvfh2wVX4NftfnfjcZWIKK6EQDWtTTsYwjfQBnsqkThAZP5OlDmg5S3g22gSqMWhAxr2O4MydSJHnQ/640?wx_fmt=jpeg" data-type="jpeg" data-w="258" style="float: left;box-sizing: border-box !important;word-wrap: break-word !important;visibility: visible !important;width: auto !important;" width="auto"  /></p><p style="max-width: 100%;min-height: 1em;letter-spacing: 0.544px;text-indent: 0em;white-space: normal;color: rgb(62, 62, 62);font-size: 12px;font-family: Arial, Verdana, sans-serif;line-height: 1.75em;background-color: rgb(255, 255, 255);box-sizing: border-box !important;word-wrap: break-word !important;"><span style="max-width: 100%;font-size: 14px;box-sizing: border-box !important;word-wrap: break-word !important;">维修咨询：QQ: &nbsp;712638 404</span><br style="max-width: 100%;box-sizing: border-box !important;word-wrap: break-word !important;"  /></p><p style="max-width: 100%;min-height: 1em;letter-spacing: 0.544px;text-indent: 0em;white-space: normal;color: rgb(62, 62, 62);font-size: 12px;font-family: Arial, Verdana, sans-serif;line-height: 1.75em;background-color: rgb(255, 255, 255);box-sizing: border-box !important;word-wrap: break-word !important;"><span style="max-width: 100%;font-size: 14px;box-sizing: border-box !important;word-wrap: break-word !important;">设备咨询: &nbsp; QQ: &nbsp;712638 405</span></p><p style="max-width: 100%;min-height: 1em;letter-spacing: 0.544px;white-space: normal;color: rgb(62, 62, 62);font-size: 16px;font-family: 微软雅黑;line-height: 24.381px;background-color: rgb(255, 255, 255);box-sizing: border-box !important;word-wrap: break-word !important;"><span style="max-width: 100%;font-size: 14px;font-family: Arial, Verdana, sans-serif;line-height: 1.75em;text-indent: 0em;box-sizing: border-box !important;word-wrap: break-word !important;">软件咨询：QQ: 712638 406</span><br style="max-width: 100%;box-sizing: border-box !important;word-wrap: break-word !important;"  /></p><p style="max-width: 100%;min-height: 1em;letter-spacing: 0.544px;text-indent: 0em;white-space: normal;color: rgb(62, 62, 62);font-size: 12px;font-family: Arial, Verdana, sans-serif;line-height: 1.75em;background-color: rgb(255, 255, 255);box-sizing: border-box !important;word-wrap: break-word !important;"><span style="max-width: 100%;font-size: 14px;box-sizing: border-box !important;word-wrap: break-word !important;">配件咨询：QQ: &nbsp; 712638 407</span></p><p style="max-width: 100%;min-height: 1em;letter-spacing: 0.544px;text-indent: 0em;white-space: normal;color: rgb(62, 62, 62);font-size: 12px;font-family: Arial, Verdana, sans-serif;line-height: 1.75em;background-color: rgb(255, 255, 255);box-sizing: border-box !important;word-wrap: break-word !important;"><span style="max-width: 100%;font-size: 14px;box-sizing: border-box !important;word-wrap: break-word !important;">交流Q群：1106 11074</span></p><p style="max-width: 100%;min-height: 1em;letter-spacing: 0.544px;text-indent: 0em;white-space: normal;color: rgb(62, 62, 62);font-size: 12px;font-family: Arial, Verdana, sans-serif;line-height: 1.75em;background-color: rgb(255, 255, 255);box-sizing: border-box !important;word-wrap: break-word !important;"><span style="max-width: 100%;font-size: 14px;box-sizing: border-box !important;word-wrap: break-word !important;"><span style="max-width: 100%;">阿里店铺网址：</span><span style="max-width: 100%;">https://renchengyiliao.1688.com</span></span></p><p style="max-width: 100%;min-height: 1em;letter-spacing: 0.544px;text-indent: 0em;white-space: normal;color: rgb(62, 62, 62);font-size: 12px;font-family: Arial, Verdana, sans-serif;line-height: 1.75em;background-color: rgb(255, 255, 255);box-sizing: border-box !important;word-wrap: break-word !important;"><span style="max-width: 100%;font-size: 14px;box-sizing: border-box !important;word-wrap: break-word !important;">电子邮箱：sales@parts-ultrasound.com</span></p>