肺结核患儿低剂量螺旋CT扫描的图像质量评价

目的 对儿童肺结核患者行低剂量螺旋CT扫描，并对图像质量进行评价。 方法 收集2006年4月1日至2011年4月30日确诊新发初治0～15岁的肺结核患者150例，所有患儿按年龄分为3组（Ⅰ组0～岁，Ⅱ组6～岁，Ⅲ组11～15岁），每组均按完全随机方式纳入，达50例终止，分别采用常规剂量［自动曝光控制技术(AECT)］和低剂量［恒定性管电流控制技术(CCCT)］方案扫描，作自身性前后图像对比，采取双盲法对图像质量作量化评价，验证各组肺结核患儿的低剂量CT图像质量［每项图像质量控制（简称“质控”）内容为五级，采用5分制，图像质量很好为5分，较好为4分，一般为3分，稍差为2分，差为1分］。恒定式管电压120 kV,Ⅰ组AECT 100 mA，CCCT 20 mA；Ⅱ组AECT 150 mA，CCCT 30 mA；Ⅲ组AECT 150 mA，CCCT 40 mA。 结果 150例肺结核患儿不同低剂量方案螺旋CT扫描后评价结果：（1）肺窗显示的病灶范围、病灶密度、病灶清晰度、病灶中的细节、噪声大小5项质控内容：Ⅰ组CCCT 20 mA平均得88.8（22.2±1.5）分，AECT 100 mA平均得95.1（23.7±0.8）分，差异有显著统计学意义(t=7.9，P＜0.001）；Ⅱ组CCCT 30 mA平均得97.2（24.2±0.9）分，AECT 150 mA平均得98.2（24.7±0.5）分，差异无统计学意义(t=2.9，P＞0.05）；Ⅲ组CCCT 40 mA平均得98.3（24.6±0.6）分，AECT 150 mA平均得99.0（24.7±0.5）分，差异无统计学意义(t=1.7，P＞0.05）。（2）纵隔窗显示的肌肉肋骨脂肪、肺门大血管、纵隔内食管与周围组织对比度、心房心室、下腔静脉5项图像质控内容：Ⅰ组CCCT 20 mA平均得87.8（21.9±1.5）分，AECT 100 mA平均得95.4（23.8±1.1）分，差异有显著统计学意义（t=7.2，P＜0.001）；Ⅱ组CCCT 30 mA平均得97.0（24.2±0.8）分，AECT 150 mA平均得98.7（24.5±0.5）分，差异无统计学意义（t=2.2，P＞0.05）；Ⅲ组CCCT40 mA平均得97.6（24.4±0.7）分，AECT 150 mA平均得98.9（24.7±0.4）分，差异无统计学意义(t=2.7，P＞0.05)。（3）肺结核病灶图像质量Ⅰ组CCCT 20 mA平均得85.6（3.72±0.73）分，AECT 100 mA平均得95.3（4.66±0.66）分，差异有显著统计学意义（t=9.34，P＜0.001）；Ⅱ组CCCT 30 mA平均得96.0（4.56±0.54）分，AECT 150 mA平均得98.8（4.74±0.44）分，差异无统计学意义(t=1.99，P＞0.05）；Ⅲ组CCCT 40 mA平均得97.6（4.72±0.45）分，AECT 150 mA 平均得99.2（4.84±0.37）分，差异无统计学意义(t=1.66，P＞0.05)。 结论 恒定式管电压120 kV不变，使用0～岁组CCCT 20 mA、6～岁组CCCT 30 mA、11～15岁CCCT 40 mA等不同低剂量螺旋CT扫描均能较好地诊断儿童肺结核。

Evaluation on image quality of children’s pulmonary tuberculosis with low-dose spirial CT

Objective To evaluate the image quality of children’s pulmonary tuberculosis (CPTB)with low-dose spirial CT scanning. Methods One hundred and fifty new initial treated children diagnosed with CPTB about 0-15 years old have been randomly recruited. Routine dose using AECT (automatic exposure control technique) and low-dose using CCCT (constant current control technique)spirial CT scanning were performed in 150 children with CPTB prospectively. Two imaging quality were evaluated by the double-blind method. GroupⅠwas 0- years olds scanned by AECT 100 mA and CCCT 20 mA; groupⅡ was 6- years olds scanned by AECT 150 mA and CCCT 30 mA; groupⅢ was 11-15 years olds scanned by AECT 150 mA and CCCT 40 mA. Results The results with different low-dose spirial CT scanning were as follows: (1)The contents of imaging quality controlling including range, density, resolution, details and noise of lesions in lung window were as below: the average scores of CCCT 20 mA and AECT with 100 mA in groupⅠwere 88.8 (22.2±1.5) and 95.1 (23.7±0.8) with significant difference(t=7.9, P<0.001). The average scores of CCCT 30 mA and AECT with 150 mA in group Ⅱ were 97.2(24.2±0.9) and 98.7(24.7±0.5) with no significant difference (t=2.9, P>0.05). The average scores of CCCT 40 mA and AECT with 150 mA in group Ⅲ were 98.3(24.6±0.6) and 99.0(24.7±0.5) with no significant difference (t=1.7, P>0.05). (2)The contents of imaging quality controlling including muscle and ribs and fat, hilum and main vessels, esophagus and surrounding tissue contrast in mediastinum, atrium and ventricle, inferior vena cava in mediastinum window were as below: the average scores of CCCT 20 mA and AECT with 100 mA in groupⅠwere 87.8(21.9±1.5) and 95.4 (23.8±1.1) with significant difference(t=7.2, P<0.001). The average scores of CCCT 30 mAand AECT with 150 mA in group Ⅱ were 97.0（24.2±0.8）and 98.7（24.5±0.5） with no significant difference(t=2.2，P＞0.05). The average scores of CCCT 40 mA and AECT with 150 mA in group Ⅲ were 97.6(24.4±0.7) and 98.9(24.7±0.4) with significant difference (t=2.7, P>0.05). (3) The imaging quality of lesions of CPTB were as below: the average scores of CCCT 20 mA and AECT with 100 mA in groupⅠwere 85.6(3.72±0.73) and 95.3 (4.66±0.66) with significant difference(t=9.34, P<0.001). The average scores of CCCT 30 mA and AECT with 150 mA in group Ⅱ were 96.0(4.56±0.54) and 98.8 (4.74±0.44) with no significant difference (t=1.99, P>0.05). The average scores of CCCT 40 mA and AECT with 150 mA in group Ⅲ were 97.6(4.72±0.45) and 99.2(4.84±0.37) without significant difference (t=1.66, P>0.05). Conclusion The imaging got with low-dose spirial CT scanning could be used to diagnose CPTB.