Study On The Relationship Between Contrast-enhanced Ultrasound And Microvessel Density In Pancreatic Cancer

Objective:1. To compare the difference of quantitative parameters of contrast-enhanced ultrasound(CEUS) time-intensity curve in pancreatic cancer and paraneoplastic normal pancreas parenchyma.2. To investigate the relationship of these parameters and micro-vessel density(MVD) in pancreatic cancer.Methods:Thirty two patients with thirty two lesions confirmed as pancreatic cancer pathologically by surgery were studied, including3well-differentiated nodules,11moderately differentiated nodules and18poor differentiated nodules. Each patient was examined by CEUS using pulse inversion harmonic imaging (PIHI) with low mechanical index and second generation micro-bubble contrast medium(SonoVue, Bracco, Milan, Italy) as echo-enhancing agent within a week before surgery. First, the pancreas was scanned with a conventional sonogram and the color doppler flow signals of the lesions were scored. Then CEUS images were observed continually on real time and the entire scanning process was recorded for5minutes. Enhancement patterns of each lesion were analyzed during the whole vascular phase. The regions of interests (ROI) was in the lesions and the paraneoplastic pancreas parenchyma approximately the same depth, avoiding necrosis and large vessels, and the time-intensity curve was made by QLAB software. The parameters(enhancement beginning time, peak intensity time, peak intensity of lesion and enhancing slope rate)were analyzed. The tumor specimens were stained with hematoxylineosin(HE) and two professional pathologists, who were blinded to the results from CEUS, evaluated histopathologic diagnosis alone. MVD in nodules were detected by staining immunohistochemically with anti-CD34antibody. The difference of parameters in pancreatic cancers and paraneoplastic normal pancreas parenchyma were compared, such as enhancement beginning time, peak intensity time, peak intensity of lesion and enhancing slope rate. And then we analyzed the relationship between these parameters and MVD in pancreatic cancers.Results:(1Enhancement beginning time, peak intensity of CEUS is different in pancreatic cancer and normal pancreas,the enhancement beginning time of pancreatic cancer is later than normal pancreas,the peak intensity of lesion is lower than normal pancreas, there is statistically significance (P<0.05); the peak intensity time, enhancing slope rate is no difference between them, there is no statistically significance (P>0.05).(2) The peak intensity of CEUS time-intensity curve is positively correlated with MVD (r=0.69, P<0.05), enhancement beginning time,the peak intensity time and enhancing slope rate do not correlate with MVD (P>0.05)Conclusion:(1) CEUS as a imaging method of evaluating pancreatic blood supply and hemodynamics, can make quantitative analysis of perfusion, provide important information for the diagnosis and differential diagnosis of pancreatic diseases, help evaluate biological behavior.(2)The peak intensity of CEUS time-intensity curve may reflect indireetly MVD in pancreatic cancer, CEUS before operation can evaluate the generation of angiogenesis, and has a potential role in choosing treatment, evaluating prognosis, and evaluating effete of anti-angiogenesis drugs.