Assessment of pulmonary function using pixel indexes of multiple-slice spiral CT low-dose two-phase scanning in chronic obstructive pulmonary disease / 中华放射学杂志

ABSTRACT

Objective To explore the values of pixel indexes (PI) with multiple-slice spiral CT low-dose two-phase scanning for assessing the pulmonary function in chronic obstructive pulmonary disease (COPD).Methods Thirty-six patients with COPD (COPD group)and 30 healthy people (control group)underwent pulmonary function test (PFT).Chest 64-MSCT low-dose (50 mAs) scanning at full inspiration and expiration,routine scanning (100 mAs) at inspiration were performed.The effective dose (ED) was calculated.The lung was divided into three regions ( upper,middle,lower).PI of lung were divided into five groups-960--1024, -910--960, -800--910, -700--800,-400--700.ThePI-910 (sum of the PI under -910 HU) of low-dose scanning at each region were measured and calculated using pulmo software. All PI included PIin-910,PIex-910,PIin-910-PIex-910, PIex-910/PIin-910 and (PIin-910-PIex-910)/PIin-910.All patients underwent PFT within 3 days after 64-MSCT canning,FEV1％ and FEV1/FVC were selected for comparison. Results The PIin in three regions ( - 960 - - 1024,-910 - -960,-800 - -910) were statistically significant between normal and COPD groups( U =0.00,57.00,20.50,P ＜ 0.01 ). The PIex in all regions were statistically significant ( U =0.00,0.00,71.52,191.00,6.00,P ＜ 0.01 ). PI-910--1024 at expiration and inspiration were correlated with FEV1％ and FEV1/FVC( r =- 0.548,- 0.664,- 0.752,- 0.781,P ＜ 0.01 ).PIin -910,PIex -910,PIex-910/PIin -910,( PIin -910-PIex -910 )/PIin -910 had a good correlation with FEV1％ and FEV1/FVC ( r =- 0.548,- 0.664,- 0.752,- 0.781,- 0.674,- 0.642,0.674,0.642,P ＜ 0.01 ).Conclusion Pixel indexes of 64-MSCT low-dose two-phase scanning can be used to evaluate pulmonary function in COPD patients.