Image quality and dose in computed tomography
Image quality and dose in computed tomography
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DOI：
10.1007/s003300050114
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发表时间：
1997-02-01
影响因子：
5.9
通讯作者：
Hansen, J
中科院分区：
文献类型：
--
作者：
Jurik, AG;Jessen, KA;Hansen, J
CT 期间患者受到的辐射暴露相对较高，因此优化剂量以使其尽可能低但仍符合所需的诊断图像质量非常重要。没有确定的方法来测量诊断图像质量；因此，为腹膜后空间和纵隔定义了一组必须满足最佳图像质量的图像质量标准。这些图像质量评估标准的使用基于在 7 个不同 CT 单位进行的 113 次腹膜后检查和 68 次纵隔检查进行了测试。除一项外，所有标准均被发现可用于测量诊断图像质量。是否达到标准与不同科室给予的辐射剂量有关。通过检查腹膜后间隙，有效剂量在 5.1 至 20.0 mSv（毫西弗）之间变化，并且剂量与图像质量标准的“是”得分高百分比之间存在轻微相关性。对于纵隔检查，剂量范围为4.4-26.5 mSv，高剂量下图像质量没有显着提高。不同CT设备的剂量差异很大，部分原因是检查程序的差异，特别是切片数量和mAs（毫安秒），但不同扫描仪之间固有的剂量差异也起了一定作用。
Radiation exposure to the patient during CT is relatively high, and it is therefore important to optimize the dose so that it is a low as possible but still consistent with required diagnostic image quality. There is no established method for measuring diagnostic image quality; therefore, a set of image quality criteria which must be fulfilled for optimal image quality was defined for the retroperitoneal space and the mediastinum. The use of these criteria for assessment of image quality was tested based on 113 retroperitoneal and 68 mediastinal examinations performed in seven different CT units. All the criteria, except one, were found to be usable for measuring diagnostic image quality. The fulfilment of criteria was related to the radiation dose given in the different departments. By examination of the retroperitoneal space the effective dose varied between 5.1 and 20.0 mSv (milli Sievert), and there was a slight correlation between dose and high percent of ''yes'' score for the image quality criteria. For examination of the mediastinum the dose range was 4.4-26.5 mSv, and there was no significant increment of image quality at high doses. The great variation of dose at different CT units was due partly to differences regarding the examination procedure, especially the number of slices and the mAs (milli ampere second), but inherent dose variation between different scanners also played a part.