Clinical value of CARE Dose 4D technique in decreasing CT scanning dose of adult chest / 中华放射医学与防护杂志

ABSTRACT

Objective To investigate the value of CARE Dose 4D technique in decreasing radiation dose and improving image quality of multi-slice spiral CT in adult chest scanning.Methods 100patients of chest CT scanning were equally divided into study group and control group randomly.CARE Dose 4D Technique was used in study group.Effective mAs value,volume CT dose index (CTDIvol) and dose length product (DLP) were displayed automatically in machine while chest scanning; those values and actual mAs value of every image were recorded respectively.The image quality at apex of lung,lower edge of aorta arch,middle area of left atrium and base of lung on every image of 400 images was judged and classified as three level (excellent,good,poor) by two deputy chief physicians with double blind method,the image noise at corresponding parts was measured.Results While setting 80 mAs for quality reference mAs,the effective mAs value in study group most decreased 44 mAs than control group with an average decrease of 9.60( 12.0% ) ,CTDIvol with 4.75 mGy with an average decrease of 0.95 mC y( 11.0% ) ,DLP 99.50% in study group,with 98.0% in control group.But it was higher at apex of lung and base of lung,lower at middle area of left atrium,and similar at lower edge of aorta arch in study group than contrast group.The image noise were lower at apex of lung and base of lung in study group than control group (t =6.299 and 2.332,all P ＜ 0.05 ) ,higher at middle area of left atrium in study group than control group (t=3.078,P ＜0.05) and similar at lower edge of aorta arch in study group than control group (t =1.191,P ＞0.05).Conclusions CARE Dose 4D technique provides a function regulated mAs real-time on line,it not only raises utilization rate of radiation and decreases radiation dose,but also promises and increases image quality in chest CT scanning,and has some clinical significance.