Clinical application of low-dose chest CT on diagnostic imaging for AIDS patients with normal PCP weight / 重庆医学

ABSTRACT

Objective To evaluate the feasibility and establish the corresponding scanning plan through the clinical application of low-dose CT on diagnostic imaging for 111 AIDS patients with pnenmocystsis carinii pneumonia (PCP)and normal weight .Methods The thesis applied American GE(General Electric Company )FII double-row spiral CT scanner and the kV value is fixed to be 120 kV with the conventional dose (automatic mAs) and low-dose scanning applied respectively during the diagnosis .Meanwhile ,the low-dose scanning was carried out randomly in 50 mAs(50 mAs group) ,40 mAs(40 mAs group) and 30 mAs(30 mAs group) ,and then ,the iconographical imaging quality and radiation dose were analyzed ,the respective low-dose scanning plans was formulated at last .Results The high-quality film ratios for conventional close and 50 mAs group were 70 .3% and 62 .2% respectively ,and the good film ratios were 29 .7% and 37 .8% ,while no poor films occurred in both groups .The high-quality film ratios for conventional close and 40 mAs were 67 .6% and 56 .8% ,the the good film ratios were 32 .4% and 43 .2% and no poor films ,either .The high-quality film ratios for conventional close and 30 mAs were 70 .3% and 56 .8% ,the good were 29 .7% ,43 .2% and no poor films showed between both groups .From the results ,the consequential imaging films mainly show high and good quality ,all films meet the imaging diagnosis requirements and the difference are not statistically significant (P> 0 .05) .The radiation doses of conventional dose and low dose scanning (50 mAs ,40 mAs and 30 mAs groups) were 7 .6 mGy ,2 .6 mGy ,2 .1 mGy and 1 .5 mGy respectively , while the least radiation doses was for 30 mAs group and the corresponding dose is only 19 .8% of the original .The results from 111 patients applied conventional dose (automatic mAs) and low dose scanning all meet the imaging diagnosis requirements without any missed or erroneous diagnosis .Conclusion The chest low-dose CT scanning for AIDS patients with PCP and normal weight can fully meet the clinical diagnosis and treatment ,so it is practical and feasible .Meanwhile ,the conventional-dose scanning can be ap-plied at first and low-dose CT scanning later for reexamination to ensure the stability of image quality .For low-dose chest CT scan-ning ,the voltage fixed is 120 kV and the current 30 mAs .