摘要
目的探讨减轻和消除双上肢均不能上举患者胸腹部CT图像伪影的扫描技术，提高图像质量。方法选取2004年3月至2009年5月间行胸腹部CT检查的双上肢均不能上举患者61例。2007年6月前31例双上肢均不能上举患者按常规体位行CT扫描（常规组，双上肢自然放置于身体两侧），分析胸腹部CT图像伪影的表现和发生机理。2007年6月以后的30例患者采用改进后的技术行cT扫描（改进组，改变双上肢和胸椎的相对位置，使他们不在同一条直线上），同时选取30例双上肢均能上举患者（对照组）进行比较。由2名CT主管技师和1名影像诊断副主任医师在不知道扫描方法的情况下对3组患者图像伪影进行双盲法评价分级（分为严重、较重、中、轻和无5级），测量3组患者图像伪影区和非伪影区的肝脏CT值和图像噪声值，并计算出平均值。3组患者图像伪影分级评价结果比较采用χ2检验，肝脏cT值和图像噪声差异比较采用单因素方差分析。结果常规组严重伪影11例、较重伪影15例、中度伪影5例；改进组中度伪影6例、轻度伪影15例、无伪影9例；对照组轻度伪影8例、无伪影22例，改进组的图像质量明显优于常规组（χ2=95．32，P〈0．01）。无伪影区肝脏CT值和图像噪声值常规组分别为（54．5±3．0）HU和10．7±2．4，改进组为（52．0±3．5）HU和10．7±0．5，对照组为（53．7±3．1）HU和9．9±0．5。伪影区肝脏CT值和图像噪声值常规组分别为（41．7±8．4）HU和17．9±2．6，改进组的为（53．1±6．9）HU和11．0±0．7，对照组为（54．1±2．4）HU和9．9±0．5。常规组图像伪影区的肝脏CT值和图像噪声变化范围明显增大，噪声平均值也大幅增加，明显高于改进组和对照组，与改进组、对照组的差异具有统计学意义（F值分别为36．352、235．848，P值均〈0．01）。结论双上肢均不能上举患者做胸腹部CT扫描时，在常规扫描参数下，只需改变双上肢和胸椎的相对位置，使三者不在同一条直线上，伪影就会明显减轻或消失。
Objective To explore a new scanning technique to reduce and avoid image artifacts of thoracoabdominal CT and improve image quality for patients who cannot raise their arms. Methods Sixty-one patients with arm-raising disability between March 2004 and May 2009 were enrolled in the study. Thirty-one cases before June 2007 were scanned with their arms beside their body （control group） , 30 cases after June 2007 were scanned with their arms shifting to different imaging planes of the spine（ study group）, and another 30 patients who can raising their arms were taken as routine group. The images artifacts were blindly evaluated by 5-points scale （severe, less severe, moderate, minimum and no artifact ） by 2 experienced CT technologists and one radiologist and compared between the three groups （χ2 test）. CT values and its noise of the liver with or without artifact of the three groups were measured and analyzed by one-way ANOVA test. Results In the control group, 11 cases had severe, 15 cases had less severe, 5 cases had moderate. In the study group, 6 eases had moderate, 15 cases had minimum, 9 cases had no artifact. In the routine group, 8 cases minimum and 22 cases had no artifact, hnage quality was significantly improved in the study group compared to the conventional group where χ2 = 95.32 and P 〈 0. 01. CT value and the noise of the liver without artifact were （ 54. 5 ± 3.0 ） HU and 10. 7 ± 2. 4 in the control group, （52. 0 ± 3.5） HU and 10.7 ±0.5 in the study group, （53.7 ±3. 1） HU and 9.9 ±0.5 in the routine group, respectively. CT value and noise of the liver with artifact were （41.7 ± 8.4） HU and 17.9 ± 2. 6 in control group, （53.1±6.9） HU and 11.0±0.7 in the study group, （54.1 ±2.4） HU and 9.9±0.5 in the routine group, respectively. The CT value and its noise variation with artifact were significantly higher in the control group than the study group and the control group, where F = 36. 352,235. 848, respectively and P 〈 0. 01. Conclusion The image quality can be improved and the artifact can be minimized for the patients with arm-raising disability by shifting their arm position to the different imaging planes of the spine.
出处
《中华放射学杂志》
CAS
CSCD
北大核心
2010年第2期198-201,共4页
Chinese Journal of Radiology
基金
深圳市科技局资助项目（200802011）
