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Objective: To explore MSCT features of hepatic metastases of nonhypervascular pancreatic neuroendocrine tumor(PNET) and pancreatic ductal adenocarcinoma (PDAC), and its value for differential diagnosis. Methods: A total of 21 patients with nonhypervascular PNET and 56 patients with PDAC associated with hepatic metastases were analyzed retrospectively. The CT features of hepatic metastases including tumor number, distribution, size, fusion of lesions, abnormal hepatic perfusion and the CT enhancement degree were observed and analyzed. Results: There was no significant difference of the tumor number, distribution and lesion fusion of hepatic metastases between nonhypervascular PNET and PDAC (all P>0.05). There was significant difference of the maximum diameter of hepatic metastases between nonhypervascular PNET and PDAC (P=0.03). The incidence of abnormal hepatic perfusion of PDAC was higher than that of nonhypervascular PNET (67.86% vs 28.57%,P<0.01). In arterial phase, portal phase and equilibrium phase, the enhancement index of hepatic metastases of nonhypervascular PNET were all higher than that of PDAC(P<0.01). Logistic regression analysis showed that only the enhancement index in arterial phase was an independent factor for differentiating hepatic metastases between nonhypervascular PNET and PDAC, with AUC of 0.97. Conclusion: The imaging features of hepatic metastases on MSCT is helpful for differentiating diagnosis of nonhypervascular PNET and PDAC.
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Objective@#To evaluate the value of different sequences magnetic resonance imaging (MRI) in rectal cancer re-staging after neoadjuvant chemoradiation therapy (NCRT).@*Methods@#The clinical data of 117 patients with rectal cancer who underwent NCRT before surgery operation in Peking University cancer hospital from January 2016 to December 2018 were retrospectively analyzed. Among 117 patients, 101 patients underwent MRI scanning before and after NCRT, and 16 patient underwent MRI scanning after NCRT; T2 weighted imaging (T2WI) and diffusion weighted imaging (DWI) scanning were performed in all patients, and dynamic contrast enhancement (DCE) scanning was performed in 96 patients. T2WI, T2WI combined with DWI, T2WI combined with DCE were used for T re-staging of rectal cancer after NCRT respectively, and the results of which were compared with those of pathology after operation.@*Results@#The sensitivity of diagnosis of ypT0-2 rectal cancer after NCRT using T2WI combined with DWI, T2WI combined with DCE respectively was significantly higher than that using T2WI: 52.7% (29/55) and 30.4% (14/46) vs. 10.9% (6/55), and there was statistical difference (P<0.05). The accuracy rate and specificity of diagnosis of ypT3 and ypT4 rectal cancer after NCRT using T2WI combined with DWI were significantly higher than that using T2WI, with an accuracy rate of 60.7% (71/117) vs. 47.0%(55/117) and 92.3% (108/117) vs. 80.3% (94/117), and a specificity of 55.9% (33/59) vs. 23.7% (14/59) and 92.9% (105/113) vs. 80.5% (91/113), and there were statistical differences (P<0.05). The accuracy rate of down-staging after NCRT using T2WI combined with DWI was significantly higher than that using T2WI: 72.3% (73/101) vs. 58.4% (59/101), and there was statistical difference (P<0.05); there was no significant difference in accuracy rate between using T2WI and using T2WI combined with DWI and between using T2WI combined with DWI and using T2WI combined with DCE (P > 0.05).@*Conclusions@#T2WI combined with DWI is superior to T2WI in re-staging of rectal cancer after NCRT.
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Objective To study the distribution characteristics of intraperitoneal free gas and the location value of the site of gastrointestinal perforation using multi-slice CT (MSCT).Methods 60 cases of gastrointestinal perforation were retrospectively collected.The distribution of the intraperitoneal free gas in CT image was analyzed and observed.The digestive tract were divided to the upper digestive tract and the lower digestive tract by Treitz ligament.The distribution of the intraperitoneal free gas was analyzed using χ2 test.The distribution of the intraperitoneal free gas between each different perforational site was analyzed.Results 38 cases of the site of gastrointestinal perforation located in upper gastrointestinal tract and 22 cases located in lower gastrointestinal tract,there was statistically significant difference between the upper digestive tract and the lower digestive tract about the distribution of the intraperitoneal free gas(χ2=22.33,P0.05).In the cases of lower gastrointestinal tract perforation,11 cases of the site located in bowel and 11 cases located in colon,there was statistically significant difference between bowel and colon(χ2=8.98,P<0.05).Conclusion The MSCT distribution of the intraperitoneal free gas has important value in localization diagnosis of gastrointestinal perforation.
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OBJECTIVE:To study the chemical constituents of Sedum lineare. METHODS:Silica gel column chromatogra-phy,TLC and crystallization were adopted to isolate the chemical constituents of S. lineare. And chemical structures were analyzed and identified based on physicochemical properties and spectral data of compounds. RESULTS:A total of 6 sterols and 2 triterpe-noids were isolated from petroleum ether fraction of S. lineare,which were identified as stigmaster-5-ene-3β-ol-7-one(1),stigmas-ter-5-ene-3β,7α-diol(2),daucosterol(3),daucosterol palmitate(4),β-sitosterol(5),stigmaster-7-ene-3β-ol(6),δ-amyrin(7),andδ-amyrone(8)respectively. CONCLUSIONS:Compounds 3,4 and 7 are isolated from S. lineare for the first time,and compound 4 is isolated from genus S.lineare for the first time. The study has laid certain foundation for the quality evaluation of S. lineare.
