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Objective:To evaluate the diagnostic efficacy of contrast enhanced computed tomography (CT) at early arterial phase and late arterial phase for detecting pancreatic carcinoma with small liver metastases (<1 cm).Methods:The enhanced CT data of 93 patients with pathologically confirmed pancreatic carcinoma admitted in the First Affiliated Hospital of Nanjing Medical University were retrospectively analyzed. The patients were randomly divided into the early arterial phase group (47 patients with the early arterial phase and portal venous phase scanning) and the late arterial phase group (46 patients with the late arterial phase and portal venous phase scanning) according to random number method. Number, maximum diameter, enhancement features of small liver metastases in two groups were observed. The receiver operating characteristic curve (ROC) was drawn and the area under the curve was calculated. The accuracy, sensitivity, specificity, positive predictive value, and negative predictive value were also evaluated.Results:In the early arterial phase group, 21 of 47 patients had 28 small liver metastases with the maximum diameter of (7.33±1.40)mm. And in the late arterial phase group, 20 of 46 patients had 29 small liver metastases with the maximum diameter of (7.69±1.67)mm. There was not significantly statistical difference between the two groups ( P>0.05). Small liver metastases were more likely to present rim enhancement at the late arterial phase (69.0%). The area under curve of ROC of diagnostic performance in the early and late arterial phase were 0.657(95% CI 0.531-0.782), 0.810(95% CI 0.672-0.947), respectively. For the early phase group, the accuracy, sensitivity, specificity, positive predictive value, and negative predictive value were 68.1%, 61.9%, 75.0%, 88.5%, 42.9%, respectively. The accuracy, sensitivity, specificity, positive predictive value, and negative predictive value in the late group were 82.6%, 65.7%, 100%, 100%, 75.8%, respectively. Compared with the early arterial phase group, the late arterial phase group showed higher performance in detecting small liver metastases. Conclusions:Enhanced CT at the late arterial phase improves the detection of small liver metastases in patients with pancreatic carcinoma, aiding in accurate staging preoperatively.
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Objective To investigate the computed tomography (CT) features of autoimmune pancreatitis (AIP).Methods The CT imaging data of 33 patients with AIP confirmed by pathology and/or steroid therapy were retrospectively analyzed.Image analysis including the shape of pancreas, density of lesion, contrast enhancement, the changes of pancreatic duct and biliary duct, peripancreatic appearances and adjacent organ involvement.T test was performed for statistical analysis.Results Among 33 patients with AIP, 23 cases (70%) with pancreatic parenchyma diffuse enlargement, eight cases (24%) with partial enlargement and two cases (6%) with normal pancreas.The lesions appeared hypoattenuating or isoattenuating on plain CT scan.After contrast-enhanced scan, the average CT values of lesions were (75.7±17.0) Hu at arterial phase, which was lower than that of venous phase (90.7±12.0) Hu, and the difference was statistically significant (t=3.378,P=0.002).The lesions demonstrated as progressive enhancement at venous phase.Among 33 patients, the main pancreatic duct was visible in six patients (18%).Sixteen patients (48%) presented with intrahepatic and extrahepatic biliary tract dilatation caused by intrapancreatic common bile duct stenosis.Thickened envelope-like structure around the lesions, presenting as capsule sign was seen in 14 patients (42%).Extra-pancreatic organ involvement was found in seven patients including three cases of kidney involvement.After treated with steroid, seven patients repeated CT which showed different degrees of improvement.Conclusion The main CT findings of AIP are diffuse and partial enlargement of pancreas with progressive enhancement at venous phase, envelope-like structure around pancreas, and stenosis of intrapancreatic common bile duct, which are important in the diagnosis and differential diagnosis of AIP.
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Objective To evaluate the response of the lung tumor xenografts in nude mice to antiangiogenic treatment from perspectives of anatomic,vessel function,cellular and molecular level using the multimodality imaging techniques including optical imaging,dynamic contrast enhanced MRI(DCE-MRI)and diffusion weighted imaging(DWI).Methods The green fluorescent protein(GFP)was transplanted labeled using GFP-expressing NCI-H460 cells.After the transfection of GFP,NCI-H460 cells were implanted subcutaneously into nude mice.Ten days after implantion,12 nude mice whose tumor xenografts grew to 0.5-1.0 cm in the maximum diameter were randomly divided into 2 groups,and injected with phosphate-buffered saline and recombinant human endostatin respectively.Then the nude mice in the two groups underwent optical imaging,DCE-MRI and DWI.The volumes,photon counts,the quantitative MR vessel functional parameters including volume transfer constant(Ktrans),rate constant(Kep),volume of extravascular extracellular space(Ve)and maximum area under the enhancement curve(iAUC),and apparent diffusion coefficient(ADC)values of the tumors were recorded.Then tumors were collected and observed using the transmission electron microscopy and pathology examination,including HE staining,microvessel density(MVD)and the expressions of vascular endothelial cell growth factor(VEGF).The Kep and VEGF expressions in experimental group and control group were compared with x2 text,and other values were compared with t test.The Pearson and Spearman test were used for analyzing the correlation of values in the two groups.Results Seven days after inoculation,the fluorescence signals were detected and grew with the growth of the tumors.On the 7 day after starting therapy,the photon counts of experimental group and control group were(2.51 ± 2.43)× 1010(photon/sec)and(5.77 ± 3.25)× 1010(photon/sec),respectively with no significant differences(t =1.964,P ＞0.05).Two sample t test showed that the tumor volumes in experimental group were smaller than those in control group[(365 ± 56)vs(987 ± 265)mm3,t =0.001,P ＜ 0.01].There was a positive correlation(r =0.673,P ＜ 0.05)between the photon counts and the volumes of the tumors.The mean Ktrans,Kep,Ve and iAUC of experimental group were:(0.055 ±0.012)min-1,0.335(0.184—0.894)min-1,0.297 ± 0.041 and 7.334 ± 3.930,and those for control group were:(0.117 ± 0.027)rin-1,0.417(0.324-1.736)min-1,0.326:±:0.062 and 13.280 ± 4.245.There were significant differences of Krans and iAUC(t =5.155,2.518,P ＜ 0.05)between experimental group and control group.And there was a positive correlation(r =0.715,P ＜ 0.0 1)between the values of iAUC and MVD,but not the expressions of VEGF(r =0.484,P ＞ 0.05).The values of ADC in experimental group were higher than that in control group[(791 ± 38)× 10-6 vs(737 ± 43)×10-6 mm2/s],and there were significant differences(t =-2.299,P ＜ 0.05).Two sample t test showed that the MVD in experimental group were lower than that in control group[(11.9 ± 4.8)vs(19.2 ±4.3)item/hpf,t =2.774,P ＜ 0.05].The VEGF expressions in experimental group were lower than that in control group(x2 =4.000,P ＞ 0.05).It was observed that some cells in experimental group had degenerated and apoptotic signs by the electron microscopy.Conclusions Evaluating the response of lung tumor xenografts to antiangiogenic treatment at anatomical,vessel functional,cellular and molecular level using the multimedality imagings is applicable.And it will be in favour of evaluating the therapeutic effect promptly.