| The diagnostic value of Tl weighted perfusion imaging of pancreatic ductal adenocarcinoma on3.0T MRPurpose:To investigate the diagnostic value of T1weighted perfusion imaging of pancreatic ductal adenocarcinoma (PDA) on3.0T MR.Materials and Methods:75cases of suspected pancreatic tumors underwent T1-weighted perfusion MR imaging. Among them23cases of PDA,3cases of solid pseudopapillary tumor,3cases of neuroendocrine tumor,2cases of mass-forming pancreatitis,2cases of ampulla adenocarcinoma, proven by histopathology were included in this study. The parameters of T1weighted perfusion imaging were recorded and compared.Results:The parameters of T1weighted perfusion imaging of PDA tissue and non-cancer tissue did not show significant difference between two and three compartment model. The CER and Kep-2C of non-cancer tissue with dilatation of pancreatic duct were significantly different with those of non-cancer tissue without dilatation of pancreatic duct. PeakT, MxSIp, Ktrans, Kep showed significant differences between PDA tissue and non-cancer tissue. ROC curves showed the areas under the curve of differentiating PDA tissue from the non-cancer tissue were0.82,0.79,0.91,0.94,0.88and0.89for PeakT, MxSIp, Ktrans-2C, Kep-2C, Ktrans-3C and Kep-3respectively. The Ktrans of tumor showed significant difference among solid tumors of pancreatic district. PDA tissue showed lower MxSIp and Kep, longer PeakT than those of non-PDA tumors.Conclusion:The parameters of T1weighted perfusion imaging of PDA and non-cancer tissue do not show significant difference between two and three compartment model. The parameters of T1weighted perfusion imaging have a good diagnostic efficacy for differentiating the PDA tissue from the non-cancer tissue. The partial parameters of T1weighted perfusion imaging of non-cancer tissue can be impacted by dilatation of pancreatic duct. The parameters of T1weighted perfusion imaging show the value of differentiating solid tumors at pancreatic district. Part â…¡:The correlation of T1weighted perfusion imaging at3.0T MR and histopathology for pancreatic ductal adenocarcinomaPurpose:To discuss the correlation of T1weighted perfusion imaging at3.0T MR and histopathology for pancreatic ductal adenocarcinoma (PDA).Materials and Methods:Twenty-three patients with histopathologically proven PDA were included in this study after75cases of suspected pancreatic tumors had been performed by T1perfusion imaging. According to MR images, wax blocks and slices were selected and stained for HE, anti-VEGF, anti-CD34, anti-Ki-67(Mib-1). The relationship between the tumor parameters of T1weighted perfusion imaging and tumor differentiation, tumor fibrosis, the expression of tumor VEGF, ki-67, MVD.Results:The tumor Kep and Ve showed a significantly statistical correlation with tumor fibrosis, the tumor Ktrans-2C showed a significantly statistical correlation with the expressions of tumor VEGF, and the tumor Kep, MxSIp, CER showed a significantly statistical correlation with the expression of tumor Ki-67.Conclusion:The parameters of T1weighted perfusion imaging of PDA can be used to evaluate the degrees of tumor fibrosis, the expressions of VEGF and Ki-67. Part â…¢:Clinical applications of diffusion weighted MR imaging in the diagnosis of pancreatic ductal adenocarcinoma ONEThe effect of different respiratory control sequences, b values and gadolinium chelate contrast agent on diffusion weighted MR imaging of pancreatic ductal adenocarcinoma 1. The effect of different respiratory control sequences and b values on diffusion weighted MR imaging of pancreatic ductal adenocarcinomaPurpose:To evaluate the effect of different respiratory control sequences and b values on diffusion weighted MR imaging (DWI) of pancreatic ductal adenocarcinoma (PDA).Materials and Methods:Twenty-eight patients (16men,12women; mean age61years) with histopathologically proven PDA were included in this study after108cases of suspected pancreatic tumors had been performed by DWI. The sequences of DWI included respiratory triggered DWI (RT-DWI) and breathhold DWI (BH-DWI), which were performed with two b values (0,500s/mm2and0,1000s/mm2) respectively. The image quality (artifacts, pancreatic anatomy, PDA detection), SI of PDA, SNR of PDA, ADC value and coefficient of variation (CV) of ADC were compared among those sequences.Results:The scores of artifacts in b=1000s/mm2images were significantly lower than those of b=500s/mm2images for RT DWI and BH DWI. The scores of artifacts revealed no statistically significant difference between RT DWI and BH DWI for b=500s/mm2and b=1000s/mm2. Though the scores of PDA detection in RT-DWI were higher than those of BH-DWI, the scores of pancreatic anatomy/PDA detection did not showed statistically significant difference in all sequences. The SI and SNR of lesions in RT DWI were significantly higher than those of BH DWI for b500DWI and b1000DWI. The SI and SNR of lesions in b500DWI were significantly higher than those of b1000DWI for RT DWI and BH DWI. The ADC values of lesions in RT DWI were significantly higher than those of BH DWI for b500DWI and b1000DWI. The ADC values of lesions in b500DWI were significantly higher than those of b1000DWI for RT DWI and BH DWI. The CVs of ADC values of lesions did not showed statistically significant difference in all sequences.Conclusion:RH DWI has better image quality than BH DWI, and DWI with b500s/mm2has better image quality than DWI with b1000s/mm2, however they have the same ability to show PDA. Due to the shorter scanning time of BH-DWI comparing to RT DWI, BH DWI has the better clinical practical value in case of lesion detection is the primary aim. 2. The effect of gadolinium chelate contrast agent on diffusion weighted MR imaging of pancreatic ductal adenocarcinomaPurpose:To investigate the effect of gadolinium chelate contrast agent on diffusion weighted MR imaging (DWI) of pancreatic ductal adenocarcinoma (PDA).Materials and Methods:Twenty-two patients (13men,9women; mean age62years) with histopathologically proven PDA were included in this study. DWI was acquired before and after administration of gadopentetate dimeglumine (magevist) with2b-values:0and1000s/mm2. The image quality (artifacts, pancreatic anatomy, PDA detection), signal intensity (SI) of PDA, signal-to-noise ratio (SNR) of PDA, ADC value of lesions and coefficient of variation (CV) of ADC were recorded for comparison.Results:The mean time interval between the initiation of contrast administration and the start of the post-contrast DWI series was393s (range350-510). The scores of artifacts, pancreatic anatomy, PDA detection revealed no statistically significant difference between non-enhanced and enhanced images (P=0.083, P=0.175, P=0.665). The SIs and SNRs of lesions of b=1000s/mm2and b=0s/mm2images of enhanced images were significantly higher than non-enhanced images (P<0.001, P<0.001for b=1000s/mm2; P=0.001, P=0.001for b=0s/mm2). The ADC values of all PDAs revealed no statistically significant difference between non-enhanced and enhanced images (P=0.709). There was also no significant difference between non-enhanced and enhanced images in subgroups based on grades of differentiation and locations of lesions. The CVs of ADC values of lesions did not show statistically significant difference between non-enhanced and enhanced images either.Conclusion:Intravenous contrast administration does not result in a significant difference in quantitative ADC measurements when comparing pre-contrast to post-contrast DWI when acquired approximately6-7min after administration. The post-contrast DWI is feasible for diagnosing PDA. TWOThe diagnostic value of diffusion-weighted imaging of pancreatic ductal adenocarcinoma on3.0T MRPurpose:To discuss the diagnostic value of diffusion-weighted imaging (DWI) of pancreatic ductal adenocarcinoma (PDA) on3.0T MR.Materials and Methods:Twenty-eight cases of PDA,6cases of solid pseudopapillary tumor,5cases of neuroendocrine tumors,2cases of mass-forming pancreatitis,3cases of ampulla adenocarcinomas, proven by histopathology were included in this study after108cases of suspected pancreatic tumors had been performed by DWI. The sequences of DWI included respiratory triggered DWI (RT-DWI) and breathhold DWI (BH-DWI), which were performed with two b values (0,500s/mm2and0,1000s/mm2) respectively. The ADC values between PDA tissue and non-cancer tissue were compared and analyzed, as well as non-cancer tissue with or without the dilation of main duct. The ADC values among different solid lesions at pancreatic district were compared too.Results:There was significant difference between the ADCs of PDA and non-cancer tissue. ROC curve showed the areas under the curve were0.75,0.81,0.85,0.85respectively for differentiating PDA from the non-cancer tissue. Although the ADC of non-cancer tissue with dilatation of pancreatic duct was7%lower than that of non-cancer tissue without dilatation of pancreatic duct, the statistical significant difference was non be found. The ADCs of PDAs of different locations did not showed the statistical significanct difference. The ADCs among different solid lesions at pancreatic district did not show the statistical significant difference.Conclusion:The ADC value of PDA tissue is significantly lower than that of non-cancer tissue, the ADC has the good diagnostic efficacy for differentiating the PDA tissue from the non-cancer tissue. The ADC value of non-cancer tissue does not impact significantly by dilatation of pancreatic duct. Location of PDA does not impacted the ADC of PDA. ADC value is not yet used in differentiating pancreatic ductal adenocarcinoma from other solid lesions of the pancreas area. Part IVThe correlation beween diffusion weighted imaging at3.0T MR and histopathology for pancreatic ductal adenocarcinomaPurpose:To discuss the correlation between diffusion weighted imaging (DWI) at3.0T MR and histopathology for pancreatic ductal adenocarcinoma (PDA).Material and Methods:Twenty-eight patients with histopathologically proven PDA were included in this study after108cases of suspected pancreatic tumors had been performed by DWI. The sequences of DWI included RT-DWI and BH-DWI, which were performed with two b values (0,500s/mm2and0,1000s/mm2) respectively. According to MR images, wax blocks and slices were selected and stained for HE, anti-VEGF, anti-CD34, anti-Ki-67(Mib-1). The relationship between tumor ADC and tumor fibrosis, the expression of tumor VEGF, ki-67, MVD,were studied.Results:The ADC values of PDA of different grades of differentiation and fibrosis grade did not show statistically significant difference. The ADC values of PDA did not show the correlation with the grades of differentiation, fibrosis grade, Ki-67expression, and expression of VEGF, MVD.Conclusion:The ADC of PDA can not be used to reflect grades of differentiation, degree of tumor fibrosis, the expression of VEGF, the expression of Ki-67and the tumor MVD. |
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