Low KV Dual-source CT Scanning Technology In The Application Of Liver To Enhance Research

Objective: Selection of body mass index(BMI) in patients with normal range of normal liver CT enhanced scan voltage and low voltage, low voltage scanning technology in the liver enhance scanning at different times of the clinical application value.Materials and methods: select 120 routine liver CT enhanced scan of outpatient and inpatient, BMI is 18 kg/m2 < BMI < 24 kg/m2, randomly divided into control group and research group, control group 60 cases patients of 120 kv scanning, image post-processing with traditional filter back projection technique place(FBP); Group of 60 cases of patients with 100 kv scanning, image post-processing with SAFIRE iterative reconstruction technique; Two groups of tube current by CT machine, automatic adjustment, the rest of the scanning conditions are consistent, patients supine line axis scanning. Income to dual-source CT image workstation for reprocessing, selection of portal vein trunk level, record two group of arterial phase and portal phase, left and right lobe liver CT value, and calculate the average, with liver CT values of the standard deviation(SD) as the image noise; Measurement on the left side of the shaft soma CT values at the same time, calculate the average, will be the same level of subcutaneous fat as background noise background(SD), calculate and evaluate each patient arterial phase and portal phase image noise(SD), liver, signal-to-noise ratio(SNR), liver- sma vertical contrast to noise ratio(CNR), radiation dose index(CTDI), the product of gauge length(ED)(DLP) and effective doses of radiation. With double blind method, by two high qualification doctor degree of clear according to the liver and peripheral vascular and image diagnostic information for subjective ratings. The control group and the team is not at the same time the image subjective ratings of SD, SNR, CNR, and CTDI, DLP, ED line of single factor analysis of variance and multiple t test for statistical analysis.Results:1、two groups of patients in different periods, image difference was statistically significant(P < 0.05), the team SD was increased; Two groups of patients in different periods the image SNR liver, liver-shaft same CNR no statistically significant difference(P > 0.05), lower tube voltage, the image quality without change;2、group and control group in arterial phase and portal phase difference image subjective rating, the team image quality than the control group image quality to drop, but its subjective score average were greater than 3,to be able to meet the demand of clinical diagnosis.3、the research group and the control group CTDI, DLP and ED are statistically significant, the team in patients with arterial phase and portal phase by effective radiation dose fell by 52.5% and 51.3% respectively than control group;Conclusion: the liver CT enhancement in the application of low tube voltage(100 kv), automatic tube current technology can be on the premise of not affect image quality significantly reduce the radiation dose, effective dose was reduced by 51.9%.