Effect Of Different Pitch On CT Image Quality In Old People With COPD

Objective：TO make a comparison of influence on imaging quality at diff-erent pitchscan modes for old COPD of chest using64-slice CT. Methods：100patiants with oldCOPD divided into two groups.They underwent CT of tharacic with a pitch of0.984(groupA n=50),or a pitch of1.375(group B n=50).The study was performed with GE Lightspeedsys#vct64-sliceCT.All images were obtained at120kV tube voltage,200mA tube currentand5mm slice thickness.gantry rotation time0.8s. The motion artifact,image quality andimaging noise were recorded and compared beween groups by student,stest(SPSS11.5).Result:compared with Group B the motion artifact and the scan time inGroup A were reduced by26％,1.7s.Conclusion: At the same voltage and tube current,ahigher pitch (1.375)scan mode can reduce the scan time,the motion artifact and radiationdose without compromising the imaging quality.