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Purpose To explore the value of dual-layer spectral detector CT(DLSCT)in evaluating preoperative tumor staging in rectal adenocarcinoma(RA).Materials and Methods A total of 78 patients with pathologically confirmed RA in Guangdong Provincial Hospital of Chinese Medicine from May 2021 to March 2022 were involved in this retrospective study.All the patients underwent plain and dual-phase contrast-enhanced scans by DLSCT within one week before surgery.Taking pathological results as the golden standard,the accuracy rates of tumor staging were calculated and compared between the multiple-parameter maps derived from DLSCT and 120 kVp polyenergetic image.The effective atomic number(Z-eff)from plain scan,iodine concentration(IC)from arterial phase(AP)and venous phase(VP)were measured.The normalized iodine concentration(NIC)in AP and VP were calculated.The differences of Z-eff,NICAP and NICVP were compared among the pT1-2,pT3 and pT4 groups.The correlation between the pT stages and above values was assessed and the diagnostic efficiencies were analyzed.Results The overall accuracy rate(88.46%vs.67.95%;χ2=9.628,P=0.002),the pT1-2 staging accuracy rate(80.00%vs.40.00%;χ2=6.667,P=0.01),and the pT3 staging accuracy rate(88.10%vs.69.05%;χ2=4.525,P=0.033)of multiple-parameter maps derived from DLSCT were significantly higher than those of 120 kVp polyenergetic image,respectively.The Z-eff,NICAP and NICVP were significantly different among pT stage groups(F=6.456,11.029,12.698,all P<0.05)and exhibited a positive correlation with pT stages(r=0.371,0.367,0.363,all P<0.01).The areas under the curve of Z-eff,NICAP and NICVP to assess pT3-4 staging RA were 0.77,0.71 and 0.74,respectively.Conclusion The multiple-parameter maps derived from DLSCT can significantly improve the diagnostic accuracy of preoperative tumor staging of RA.Z-eff from plain scan and NIC from dual-phase helps differentiate pT1-2 from pT3-4 staging RA.
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Objective:To explore the value of dual-layer detector spectral CT quantitative parameters in evaluating the treatment response of neoadjuvant chemoradiotherapy (nCRT) in patients with locally advanced rectal cancer (LARC).Methods:The study was a cross-sectional study. From May 2021 to March 2023, a total of 52 patients with LARC who received complete nCRT and were pathologically confirmed rectal adenocarcinoma at the Guangdong Province Hospital of Traditional Chinese Medicine were retrospectively enrolled. Each patient underwent spectral CT examination before and after nCRT, including plain scan, arterial phase (AP), and venous phase (VP) scans. According to the tumor regression grade, the patients were divided into the good response ( n=20) and the poor response group ( n=32). Measurements of the primary tumor′s spectral CT parameters, including effective atomic number (Z eff) at plain scan, iodine concentration (IC), CT values of 40 keV and 100 keV virtual monochromatic image (VMI) at dual-enhanced phases, were taken before and after nCRT. Additionally, the normalized iodine concentration (NIC), spectral curve slope (λHU), and the change rate of the above parameters before and after nCRT were calculated. The independent sample t-test or Mann-Whitney U test was used to compare the differences between the two groups. The receiver operating characteristic (ROC) curve was used to assess the efficacy of various metrics in evaluating the tumor treatment response of nCRT. A binary logistic regression analysis of combined parameter results was performed for the parameters with the areas under curve (AUC)>0.75, and the AUC of the combined parameter was evaluated. Results:There were significant differences in NIC AP and λHU VP before nCRT, NIC VP and λHU VP after nCRT, and the change rates of Z eff, NIC AP, NIC VP and λHU AP between the good response group and the poor response group ( P<0.05). The remaining parameters showed no statistically significant difference ( P>0.05). The ROC curve results showed that the AUCs of the above 8 parameters for evaluating tumor treatment response of nCRT were 0.702, 0.655, 0.695, 0.769, 0.738, 0.807, 0.791, and 0.677, respectively. The AUC of the combined model of the three parameters with AUC>0.75 (λHU VP after nCRT, the change rate of NIC AP and NIC VP) was 0.869, with 80.0% sensitivity and 84.4% specificity. Conclusion:The quantitative parameters derived from spectral CT may provide new markers for evaluating the response to nCRT treatment in patients with LARC. The multi-parameter combined model can improve diagnostic efficacy.
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Objective To study CT findings of duodenal malignant tumor.Methods Plain and contrast-enhanced CT date of 20 patients with duodenal malignant tumor proved by pathology were retrospectively analysed.Results There were three adenocarcinomas, two lymphomas, three malignant gastrointestinal stromal tumors, three ampulla carcinomas, eight carcinomas of head of pancreas, one pancreatic nonfunction neuroendocrine cell carcinoma. Duodenal adenocarcinoma manifested as local irregular constriction of cavity accompanied with soft tissue mass. After enhancement, the mass manifested as moderate enhancement. Lymphoma manifested as extensive duodenal wall thickening or extracavity mass,after enhancement,the mass was manifested as mild enhancement. Malignant gastrointestinal stromal tumor manifested as massive mass with heterogeneous marked enhancement,ileus was not obvious. Ampulla carcinoma manifested as local soft tissues mass with mild and moderate enhancement in the media of duodenal descent part, intrahepatic and extrahepatic biliary duct dialated. Carcinoma of head of pancreas involving duodenum manifested as duodenal medial wall roug,mass in the head of pancreas with no enhancement, intrahepatic and extrahepatic biliary duct dilated. Pancreatic nonfunction neuroendocrine cell carcinoma involving duodenum manifested as massive mass with marked enhancement in the head of pancreas,there was indistinction between mass and duodenum, intrahepatic and extrahepatic biliary duct were non-dilation.Conclusion CT scan plays an important role in the diagnosis of duodenal malignant tumor.