Abstract: 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 mA and 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.

Key words: Tuberculosis, pulmonary/psychology, Tomography, spiral computed, Image processing, computer-assisted, Quality control, Evaluation studies