| Objective:1. To evaluate the image quality of the GSI PERFUSION spectrum image obtained by gemstone spectral imaging and perfusion(GSI PERFUSION) one-stop scan, and to explore the application value of CT energy spectrum and perfusion one station imaging.2. To investigate the ability of the GSI PERFUSION spectrum image to evaluate the blood perfusion of VX2 liver cancer in rabbits with one stop scanning. Materials and Methods:Approved by the animal experimental ethics committee of Zhengzhou University, 30 healthy New Zealand white rabbits were selected and 30 were studied. The body weight was 2 ~ 3kg, and the male and female were not limited. Rabbit VX2 liver cancer animal model was prepared by the method of "CT guided percutaneous puncture and growing VX2 tumor".Fourteenth days after inoculation, the experimental animals underwent GSI PERFUSION one-stop CT scan to generate spectral images(A group) and perfusion images; and underwent conventional CT spectral imaging to generate conventional spectral images(B group) in 24 hours. Image processing and data acquisition were carried out on the ADW4.6 workstation, The tumor tissue, normal liver tissue, abdominal aorta, portal vein and vertical spinal muscle were selected as the region of interest(ROI). All energy spectrum data are measured under the single energy image of 70 keV plus 40%Asir, image noise is the standard deviation of the CT value of the vertical spinal muscle. Calculate the contrast to noise ratio(CNR), using five points method to record the two groups of energy spectrum image focus of the overall image noise score(ONS), the overall image quality score(OQS) and 1esion conspicuity scores(LCS). 4D perfusion software generation of tumor tissues and normal liver tissue blood volume(BV), blood flow(BF), and the mean time(MTT), hepatic arterial fraction(HAF), permeability surface(PS), time to peak(TTP), maximum enhancement integral(PEI) and average slope of increase(MSI).The experimental animal anatomy of the success of the tumor will be determined after the routine energy spectrum of the dual phase enhanced scan, Samples from tumor tissue and normal liver tissue, to detect the expression of VEGF mRNA by RT-PCR, and microvessel density detection of tumor CD34 antibody and normal liver tissues(MVD).Using SPSS 21.0 statistical software for statistical analysis, The paired samples t test, Wilcoxon rank sum test, and Pearson correlation analysis were used for statistical analysis. Test level alpha =0.05. Results:1 Rabbit VX2 liver cancer model results30 experimental rabbits were not dead in two weeks, 24 rabbits form tumors in the liver, 2 rabbits with abdominal wall invasion, 1 rabbits with peritoneal metastasis, 3 rabbits had no tumor in the liver and outside the liver. 26 tumor nodules were formed in 24 rabbits with liver tumors(2 of which were 2 nodules), with a diameter of about 1.0cm ~ 3.5cm. The mortality rate was 0(0/30), and the rate of tumor formation was 80%(24/30).2 The image quality assessment of GSI PERFUSION dual phase spectrum image(A group) and the conventional dual phase spectrum image(B)A group of tumor tissue during the arterial phase CT value and CNR were higher than those in group B, the difference was statistically significant(p < 0.01), venous phase no significant difference(p > 0.05), and in dual phase image of two groups, the CT value of normal liver tissue, erector spinae, aorta, portal vein, and image noise were not statistically significant(p> 0.05).Overall image noise score(ONS): A group image noise score is lower than B group in dual phase, the difference was not statistically significant(p>0.05). Overall image quality score(OQS): A group image quality score was higher than B group in dual phase, the difference was not statistically significant(p>0.05). Lesion conspicuity scores(LCS): A group lesion conspicuity scores was higher than B group in arterial phase, the difference was not statistically significant(p>0.05); and higher than B group in venous phase, the difference was statistically significant(p < 0.01).3 Comparison of tumor tissue iodine concentration(IC) and normalized iodine concentration(NIC) in two groupsArterial phase: iodine concentration(IC) and normalized iodine concentration(NIC) of A group were significantly higher than those in B group, and the difference was statistically significant(p<0.01).Venous phase: iodine concentration(IC) and normalized iodine concentration(NIC) of A group were higher than those in B group, and there was no significant difference(p>0.05).4 Correlation between tumor tissue iodine concentration(IC), normalized iodine concentration(NIC) in GSI PERFUSION spectral imaging and perfusion parameters, VEGF/ beta-actin ratio and MVD valueTumor tissue during iodine value(IC) with BV, BF, HAF, PS were positive, the correlation coefficient were 0.527 and 0.641, 0.756, 0.602(p<0.05), and with MTT and TTP, PEI, MSI were no correlation(p>0.05); and with VEGF / p-actin ratio and MVD value also were positively related, the correlation coefficient were 0.805, 0.702(p<0.05).Tumor tissue during the arterial phase of standardization of iodine content(NIC) with BV, BF, HAF, PS were positive, the correlation coefficient were 0.617, 0.778, 0.850, 0.738(p<0.05), and wiyh the MTT showed negative correlation, the correlation coefficient was-0.550(p<0.05), and with TTP, PEI, MSI were no correlation(p>0.05); and with VEGF / p-actin ratio and MVD value were positively related, the correlation coefficient were 0.901, 0.810(p<0.05). Conclusion:1. The image quality of GSI PERFUSION spectrum image and the conventional spectrum image were similar, and GSI PERFUSION spectrum image can improve the contrast of arterial lesions. GSI PERFUSION spectrum image can be used to replace he conventional spectrum image to study.2. The iodine concentration(IC) and normalized iodine concentration(NIC) of GSI PERFUSION spectrum image can be used as a quantitative index to evaluate the blood perfusion of VX2 liver cancer in rabbits, and with the advantage of conjoint analysis combining perfusion parameters and spectrum parameters. |
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