Application Of Low-dose And Lowconcentration Isosmotic Contrast Agent CT Scan In Abdominal Examination In Children

PART? APPLICATION OF AUTOMATIC TUBE CURRENT ADJUSTMENT TECHNOLOGY IN ABDOMEN CT SCAN OF CHILDRENObjective: To explore the difference in radiation dose and image quality between the automatic tube current adjustment and the traditional scanning technology of 64-slice spiral computed tomography(CT)when applied to the abdomen imaging of children.Methods: Sixty children were included in the study.The patients were divided into two groups(A and B),A imaged with automatic tube current adjustment technology(tube voltage: 120kV;automatic tube current for preset noise index: 10;n=30)and B with the traditional scanning technology(Tube voltage: 120KV;tube current: 150mAs;n = 30).The abdominal image qualities and the CT radiation doses were quantitatively assessed and compared of the two groups.Results: No statistical significance was found between the abdomen images of group A and B in CT value,noise and signal-to-noise ratio(SNR)of abdominal aorta,erector spinae,liver,spleen and kidney(P>0.05).In group A,CT dose index volume(CTDlvol)was(4.59±0.81)mGy;dose length product(DLP)was(147.58±35.77)mGycm;effective dose(ED)was(4.42±1.07)mSv.In group B,CTDlvol was(6.70±0.00)mGy;DLP was(214.24±21.65)mGycm;ED was(6.41±0.64)mSv.Difference of the above-mentioned index were statistically significant between the two groups(P < 0.01).Conclusion: In 64-slice spiral CT examination of the abdomen of children,the appropriate application of automatic tube current adjustment does benefit the effective reduction of the radiation dose without incurring observable quality impairment of CT images.PART ? APPLIED RESEARCH OF LOW CONCENTRATION CONTRAST AGENT(IODIXANOL270)COMBINED WITH THE LOW TUBE VOLTAGE IN ABDOMINAL ENHANCEMENT CT SCAN IN CHILDRENObjective:Comparison of iodine intake,image quality and radiation dose of children with enhanced abdominal CT scanning by low tube voltage(80k V)combined with low concentration contrast agent(Iodixanol270)and traditional tube voltage(120Kv)combined with high concentration contrast agent(Iodixanol 320).Methods:19 cases(group A)who underwent abdominal enhanced CT examination were collected and conventional tube voltage(120Kv)was combined with traditional high concentration contrast agent(Iodixanol320).A total of 19(group B)children who underwent abdominal enhanced CT examination were collected using low-tube voltage(80k V)combined with low-concentration contrast agent(Iodixanol 270),and images were collected using(NI=10)intelligent milliampere scanning technology of tube current in both groups.Quantitatively and subjectively,the enhanced abdominal arterial phase images of the two groups were evaluated and the radiation dose of the two groups was compared.Results:The CT values,noise,air noise and SNR,CNR and FOM of abdominal enhancement images of the abdominal aorta and soft tissue of the two groups were statistically significant(all P <0.05),but there was no statistically significant difference between air CT values of the two groups(P>0.05).The volumetric CT dose index(CTDIvol)of group A was(2.24± 0.27)m Gy,the dose length product(DLP)was(81.21±17.97)m Gy.cm.,and the effective dose(ED)was(2.43± 0.53)m Sv.In group B,CTDIvol,DLP and ED were(1.91 ± 0.3)m Gy,(63.52 ± 21.93)m Gy.cm,(1.90 ± 0.65)respectively.The difference between the two groups was statistically significant(P <0.01).There was no significant difference in subjective score between the two groups(P>0.05).The iodine intake of the children in group A was(10.69± 1.91)g,and that of the children in group B was(9.08 ± 1.94)g.The difference between the two groups was statistically significant(P<0.05).Conclusions:Low tube voltage(80kV)combined with low concentration contrast agent(Iodixanol 270)can effectively reduce the radiation dose and the intake of iodine contrast agents in children in abdominal enhanced CT scanning and meet the needs of clinical diagnosis at the same time.