Converting dose-length product to effective dose at CT
Converting dose-length product to effective dose at CT
复制标题
DOI：
10.1148/radiol.2483071964
复制
发表时间：
2008-09-01
期刊：
影响因子：
19.7
通讯作者：
Khorasani, Mohammad R.
中科院分区：
文献类型：
--
作者：
Huda, Walter;Ogden, Kent M.;Khorasani, Mohammad R.
目的：为了确定有效剂量（艾德）每单位剂量长度产品（DLP）的转换因子为计算机断层扫描（CT）dosemetry.Materials和方法：CT剂量测定电子表格被用来计算病人的艾德值和相应的DLP值。艾德与DLP的比率是用来自四家供应商的16节CT扫描仪以及来自一家制造商的跨越25年以上的五种型号来确定的。确定沿患者轴沿着2 cm扫描长度以及头部和身体CT检查时遇到的典型扫描长度的ED与DLP比值。艾德/DLP比值与管电压的关系（千伏）进行了调查，并与电子表格获得的值进行了比较，通过使用其他两个商业可用的CT剂量测定软件包获得的值。对于2 cm扫描长度，扫描区域的变化导致与艾德的差异为30倍，但是对于临床头部和身体成像的典型扫描长度获得了低得多的变化。艾德/DLP的制造商间和制造商内差异通常较小。120 kV时的艾德/DLP代表值为2.2 μ v/mGy（.）cm（头部扫描），5.4 μ Sv/mGy（.）cm（颈椎扫描）和18 μ Sv/mGy（.）cm（身体扫描）。对于头部扫描，艾德/DLP大致与X射线管电压无关，但对于身体扫描，从80 kV增加到140 kV使艾德与DLP的比值增加了约25%。协议艾德/DLP数据的所有三个软件包一般都很好，除了颈椎检查，其中一个软件包确定的艾德/DLP的比率，大约是其他两个的两倍。结论：本文介绍了一种方法，为CT用户提供了一个实用和可靠的估计成人患者的ED通过使用显示在CT控制台上的DLP在任何给定的检查结束。(C)RSNA，2008年。
Purpose: To determine effective dose (ED) per unit dose-length product (DLP) conversion factors for computed tomographic (CT) dosimetry.Materials and Methods: A CT dosimetry spreadsheet was used to compute patient ED values and corresponding DLP values. The ratio of ED to DLP was determined with 16-section CT scanners from four vendors, as well as with five models from one manufacturer that spanned more than 25 years. ED-to-DLP ratios were determined for 2-cm scan lengths along the patient axis, as well as for typical scan lengths encountered at head and body CT examinations. The dependence of the ratio of ED to DLP on x-ray tube voltage (in kilovolts) was investigated, and the values obtained with the spreadsheet were compared with those obtained by using two other commercially available CT dosimetry software packages.Results: For 2-cm scan lengths, changes in the scan region resulted in differences to ED of a factor of 30, but much lower variation was obtained for typical scan lengths at clinical head and body imaging. Inter-and intramanufacturer differences for ED/DLP were generally small. Representative values of ED/DLP at 120 kV were 2.2 mu v/mGy (.) cm (head scans), 5.4 mu Sv/mGy (.) cm (cervical spine scans), and 18 mu Sv/mGy (.) cm (body scans). For head scans, ED/DLP was approximately independent of x-ray tube voltage, but for body scans, the increase from 80 to 140 kV increased the ratio of ED to DLP by approximately 25%. Agreement in ED/DLP data for all three software packages was generally very good, except for cervical spine examinations where one software package determined an ED/DLP ratio that was approximately double that of the other two.Conclusion: This article describes a method of providing CT users with a practical and reliable estimate of adult patient EDs by using the DLP displayed on the CT console at the end of any given examination. (C) RSNA, 2008.