CT剂量指数简介

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                    <section><section powered-by="gulangu"><section><p><img src="image/20201019/ba8293b7f09aa5e0c529073c44c5f52d_1.gif" /></p></section></section><section powered-by="gulangu"><section><section><p>CT剂量指数</p></section> <p><img src="image/20201019/867bfb3b7153a7ac1e87912a59cf8fdd_2.png" /></p> <section></section></section></section><section powered-by="gulangu"><section><section><p>&nbsp; &nbsp; &nbsp; &nbsp; CTDI(CT dose index)是设备辐射剂量特征的实用表征量。</p><p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;迄今得到公认使用的CTDI：</p><p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;CT剂量指数100（CTDI<span>100</span>）</p><p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;加权CT剂量指数（CTDI<span>w</span>）</p><p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;容积CT剂量指数（CTDI<span>vol</span>）</p><p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;CT剂量指数并不直接表征各种扫描所致受检者的剂量，但与受检者所受剂量密切相关。</p><p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;与吸收剂量的单位相同：戈瑞（Gy）或mGy</p></section></section></section><section powered-by="gulangu"><section><section><p>&nbsp;CT剂量指数100（CTDI100）</p></section> <p><img src="image/20201019/867bfb3b7153a7ac1e87912a59cf8fdd_2.png" /></p> <section></section></section></section><section powered-by="gulangu"><section><section><p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;X线CT旋转一周，将平行于旋转轴Z轴（垂直于横断面）的剂量分布D（z）沿Z轴-50mm到+50mm积分，除以层厚T的商：</p></section></section></section><section powered-by="gulangu"><section><p><img src="image/20201019/04c99a65c1df38406c1510f69b9466cb_4.jpg" /></p></section></section><section powered-by="gulangu"><section><section><p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;可以用热释探测器（TLD）在专用的插件中进行各点剂量分布的测量。</p><p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;也可以用有效长度正好为100mm的笔形电离室在通用标准剂量模型中测量。</p></section></section></section><section powered-by="gulangu"><section><section><p>加权CT剂量指数（CTDIw）</p></section> <p><img src="image/20201019/867bfb3b7153a7ac1e87912a59cf8fdd_2.png" /></p> <section></section></section></section><section powered-by="gulangu"><section><section><p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 描述CT扫描的某一断层平面上的平均剂量状况。<br  /></p><p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 可以反映多层连续扫描的平均剂量（当螺距为1时）。</p></section></section></section><section powered-by="gulangu"><section><p><img src="image/20201019/0c59ced41033923a40d7d9fd816ab1ba_6.jpg" /></p></section></section><section powered-by="gulangu"><section><section><p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;CTDI<span>100，c</span><span>：在体模中心的测量值。</span></p><p><span>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;CTDI<span>100，p</span>：在体模周边四个不同位置上测量值的平均值。</span></p></section></section></section><section powered-by="gulangu"><section><section><p>容积CT剂量指数（CTDIvol）</p></section> <p><img src="image/20201019/867bfb3b7153a7ac1e87912a59cf8fdd_2.png" /></p> <section></section></section></section><section powered-by="gulangu"><section><section><p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; CTDIvol是描述多层螺旋CT在整个容积扫描范围内的平均辐射剂量。</p></section></section></section><section powered-by="gulangu"><section><p><img src="image/20201019/4bc24cdb1e73d98298904c9c7b1ddc44_8.jpg" /></p></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><p><img src="image/20201019/b03564b81c141fca89785628ed079e58_9.jpg" /></p></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>