Air trapping: Comparison of standard-dose and simulated low-dose thin-section CT techniques
Air trapping: Comparison of standard-dose and simulated low-dose thin-section CT techniques
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DOI：
10.1148/radiol.2423060196
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发表时间：
2007-03-01
期刊：
影响因子：
19.7
通讯作者：
Gevenois, Pierre Alain
中科院分区：
文献类型：
--
作者：
Bankier, Alexander A.;Schaefer-Prokop, Cornelia;Gevenois, Pierre Alain
目的：前瞻性研究放射剂量减少对呼气薄层CT空气滞留视觉定量的影响。材料和方法：在这项伦理委员会批准的研究中，27例肺移植受者(女性12例，男性15例；平均年龄54岁+/-2[平均标准误差])在140 kVp和80 mAs(有效)下接受了呼气薄层CT检查。所有患者均给予书面知情同意。模拟了对应于60、40和20 mAs(有效)的剂量减少。原始研究和剂量减少研究中的空气滞留程度由三名独立读者评分。用方差分析评估管子电流时间乘积、阅读器、阅读时间和体重指数对平均空气滞留分数的影响。观察员之间和观察员内部的协议用加权kappa统计进行评估。结果：导管电流时间乘积(P=.222)、阅读器(P=.217)、阅读时间(P=.705)或体重指数(P=.505)对空气滞留平均得分无显著影响。在80 mA时，读取器之间的一致性很好；在较低的管电流设置下，一致性降至良好或中等。读者之间的一致性随着剂量的减少而下降，但即使在20毫安时仍保持良好。置信度也下降，平均得分从2.33+/-0.73(标准差)降至1.04+/-0.19。结论：在140kVP时，管电流时间乘积可从80 mA降至20 mA，而不影响呼气薄层CT空气滞留的视觉量化，且读数之间和读数内的一致性和读数的可信度均可接受。(C)RSNA，2007年。
Purpose: To prospectively investigate the effect of radiation dose reduction on the visual quantification of air trapping at expiratory thin-section computed tomography (CT).Materials and Methods: In this ethical committee-approved study, 27 lung transplant recipients (12 women, 15 men; mean age, 54 years +/- 2 [standard error of the mean]) underwent expiratory thin-section CT at 140 kVp and 80 mAs (effective). All patients gave written informed consent. Dose reduction corresponding to 60, 40, and 20 mAs (effective) was simulated. The extent of air trapping in both original and dose-reduced studies was scored by three independent readers. The effects of tube current-time product, reader, reading session, and body mass index on average air trapping scores were assessed with analysis of variance. Agreements between and within observers were assessed with a weighted kappa statistic. Subjective scores for diagnostic confidence were attributed (3 = high, 2 = medium, 1 = low), and their means were calculated for each tube current time product value.Results: No significant effect on average air trapping scores as a result of tube current-time product (P = .222), reader (P = .217), reading session (P = .705), or body mass index (P = .505) could be detected. At 80 mAs, agreement between readers was excellent; agreement decreased to good or moderate at lower tube current settings. Agreement within readers decreased with a decrease in dose but remained good even at 20 mAs. Confidence also decreased, with mean scores decreasing from 2.33 +/- 0.73 (standard deviation) to 1.04 +/- 0.19 when dose decreased.Conclusion: At 140 kVp, the tube current-time product can be reduced from 80 to 20 mAs without impairing the visual quantification of air trapping at expiratory thin-section CT and with acceptable decreases in agreement between and within readers and in reader confidence. (c) RSNA, 2007.