数字减影检测模体DSA-8 Plus检测教程

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                    <section><section powered-by="gulangu"><section><section><p><img src="image/20201019/27e0a381db305a1f993f8601022ff617_1.gif" /></p></section></section></section><section powered-by="gulangu"><section><section><section><section powered-by="gulangu"><section><section><p>概 &nbsp;述</p></section></section></section></section></section></section></section><section powered-by="gulangu"><section><section><p>&nbsp; &nbsp; &nbsp; &nbsp;DSA是数字X线成像（Digital&nbsp;Radiography，DR）的一个组成部分。是利用计算机处理数字化的影像信息，以消除骨骼和软组织影的减影技术，是新一代血管造影的成像技术。</p><p>&nbsp; &nbsp; &nbsp; &nbsp;数字减影血管造影的方法有几种，目前常用的是时间减影法：经导管内快速注入有机碘水造影剂。在造影剂到达欲查血管之前，血管内造影剂浓度处于高峰和造影剂被廓清这段时间内，使检查部位连续成像，比如每秒成像一帧，共得图像 10 帧。在这系列图像中，取一帧血管内不含造影剂的图像和含造影剂最多的图像，用这同一部位的两帧图像的数字矩阵，经计算机行数字减影处理，使两个数字矩阵中代表骨骼及软组织的数字被抵消，而代表血管的数字不被抵消。这样，这个经计算机减影处理的数字矩阵经数字/模拟转换器转换为图像，则没有骨骼和软组织影像，只有血管影像，达到减影目的。这两帧图像称为减影对，因系在不同时间所得，故称为时间减影法。&nbsp;</p><p>本套模体的设计用于检测 DSA 系统低对比度分辨力、减影性能等性能指标。&nbsp;模体由以下几部分构成：&nbsp;</p><p>1、模体基座</p><p>2、血管细节模块</p><p>3、低对比度分辨力模块</p><p>5、骨骼模块</p><p>6、动态阶梯模块</p><p>7、影像失真度检测模块</p><p>9、空白模块</p></section></section></section><section powered-by="gulangu"><section><section><section><section powered-by="gulangu"><section><section><p>特点</p></section></section></section></section></section></section></section><section powered-by="gulangu"><section><section><p>1、该模体独特的行走机构可实现半自动的模块减影功能，操作人员可在安全距离内通过挤压气囊来推动插件模块在照射场行走摇控操作实现减影，从而有效减少了操作人员暴露在射线下的机会。</p><p>2、不同项目的检测可通过更换不同的模块来实现。</p></section></section></section><section powered-by="gulangu"><section><section><p><img src="image/20201019/5bccbd7da72761c182631f53e36fff4b_2.jpg" /></p></section></section></section><section powered-by="gulangu"><section><section><p><img src="image/20201019/63decfe6c773fff264ba3b73b744b519_3.jpg" /></p></section></section></section><section powered-by="gulangu"><section><section><section><section powered-by="gulangu"><section><section><p>操作教程</p></section></section></section></section></section></section></section><section powered-by="gulangu"><section><section><p>1、模体基座</p><p>1.1用来放置不同的模块以实现对不同参数的测量，将基座上的白色按钮按下可将中间可移动模块取出，从而实现模块的更换。测量时将模体基座水平置于诊断床面上，模体表面与影像探测器输入面垂直距离为&nbsp;30cm，使模体在视野的中心。</p></section></section></section><section powered-by="gulangu"><section><section><p><img src="image/20201019/9b2fd3c5ab0fd36b96bb033e121e714c_4.jpg" /></p></section></section></section><section powered-by="gulangu"><section><section><p>1.2先在透视状态下进行定位观察，设备选择DSA&nbsp;Body模式。</p></section></section></section><section powered-by="gulangu"><section><section><p><img src="image/20201019/686af567c466069188bca7f108d94dc8_5.jpg" /></p></section></section></section><section powered-by="gulangu"><section><section><p>2、模拟血管最小分辨尺寸及伪影的检测</p><p>2.1将血管细节模块置入模体基座内，将影像探测器输入视野（FOV）置于最大。在自动控制减影状态下先静置进行曝光作蒙片，在蒙片和减影采集之间选择 3～5 秒的延迟，挤压气囊推动模块在照射场行走实现减影，在此状态下对含有两种不同造影剂浓度（150、300） mg/cm3 的模拟动脉血管和含有畸变尺寸为（1/4、1/2、3/4）血管宽度的模拟血管进行减影。减影后调窗宽 W 和窗位 L 使减影后影像显示最佳，所看到的最清晰的血管及畸变即为本系统的血管最小分辨尺寸。不应有明显的伪影。应能看到直径为 1mm 的模拟血管，同时应能分辨造影剂浓度为 300mg/cm3、直径 2mm 的模拟血管上 1/2 宽度的畸变模拟血管。</p></section></section></section><section powered-by="gulangu"><section><section><p><img src="image/20201019/274c28baa48088ddbd3cdd2f07c1a63c_6.jpg" /></p></section></section></section><section powered-by="gulangu"><section><section><p>3、低对比度分辨力检测&nbsp;</p><p>&nbsp; &nbsp; &nbsp;将低对比度分辨力模块置于模体支架内，该插件含有长度为 150mm 的二组不同造影剂浓度（10、5）mg/cm3，每组有三种（4.0、2.0、1.0）mm 不同直径的模拟血管，在常规减影条件下进行减影。应能均匀分辨碘浓度为5.0mg/cm3，直径 2.0mm 的模拟血管。</p></section></section></section><section powered-by="gulangu"><section><section><p><img src="image/20201019/6840ecd06a4460b2f011f4637131943a_7.jpg" /></p></section></section></section><section powered-by="gulangu"><section><section><p>4、减影性能评价&nbsp;</p><p>&nbsp; &nbsp; &nbsp;&nbsp;将骨骼厚度为(0.5、1.0、 1.5)cm的骨骼模块以垂直于血管插件方向水平放在模块基座上方，将动脉血管模块置入模体基座内，在常规减影条件下进行减影。减影后仍能清晰分辨浓度为150mg/cm3，直径2.0mm模拟血管。</p></section></section></section><section powered-by="gulangu"><section><section><p><img src="image/20201019/1100cc6004916be288f64355965f164e_8.jpg" /></p></section></section></section><section powered-by="gulangu"><section><section><p>5、动态范围评价</p><p>&nbsp; &nbsp; &nbsp; 将动态阶梯模块平放在模块支架上方，将空白模块置入模体基座内，在自动曝光条件下采集影像，调窗宽W和窗位 L 使减影后影像显示最佳，对于影像增强器，应能清晰看到DSA阶梯模块5级阶层数。</p></section></section></section><section powered-by="gulangu"><section><section><p><img src="image/20201019/a34d5b49d818ad675918f582562c9ad3_9.jpg" /></p></section></section></section><section powered-by="gulangu"><section><section><p>6、影像失真度评价</p><p>&nbsp; &nbsp; &nbsp;将影像失真度检测模块平放在模块基座上方，这是一块标准厚度 1.6 毫米表面凿孔的铝板,孔的直径是3.2 毫米, 它可以提供许多高对比度的边缘形状.将空白模块置入模体基座内，使模块基座中心与照射野中心一致，选适当的影像放大倍数进行曝光，测量影像中心圆和边界圆的最大直径，按下式计算失真度：</p><p></p></section></section></section><section powered-by="gulangu"><section><section><p><img src="image/20201019/277d3f0244e1f2d2ee641a2d375f749c_10.jpg" /></p></section></section></section><section powered-by="gulangu"><section><section><p><br  /></p></section></section></section><section powered-by="gulangu"><section><section><p><img src="image/20201019/f1746e45b4593143131f67c61b4fad90_11.jpg" /></p></section></section></section><section powered-by="gulangu"><section><section><p><img src="image/20201019/36fd4d059c15287374d329785c76e6a8_12.jpg" /></p></section></section></section><section powered-by="gulangu"><section><section><p><br  /></p></section></section></section><section powered-by="gulangu"><section><section><section powered-by="gulangu"><section><section><p>欢</p></section></section></section></section><section><section powered-by="gulangu"><section><section><p>迎</p></section></section></section></section><section><section powered-by="gulangu"><section><section><p>关</p></section></section></section></section><section><section powered-by="gulangu"><section><section><p>注</p></section></section></section></section></section></section><section powered-by="gulangu"><section><section><p><br  /></p></section></section></section><section powered-by="gulangu"><section><section><section powered-by="gulangu"><section><section><p><img src="image/20201019/6b5fd10f08aa53ec9ad7a6156c73123a_13.jpg" /></p></section></section></section></section><section><section powered-by="gulangu"><section><section></section></section></section></section><section><section powered-by="gulangu"><section><section><p>关注我们</p><p>一起涨姿势！</p></section></section></section></section></section></section></section>