Computed tomography colonography (CTC) is a well-established technique for evaluation of colorectal cancer (CRC). Signiifcant advances have been made in the technique of CTC since its inception. Besides being an excellent tool for detection of CRC, it is minimally invasive, less time-consuming and well tolerated by patients. Furthermore, it has fewer complications than conventional colonoscopy (CC) or barium enema (BE). The application of new technologies, such as electronic cleansing (EC) and dual-energy CT (DECT), enriches the examination of CTC. In 2005, a standardized reporting scheme, CT colonography reporting and data system (C-RADS), was put forward by the working group on virtual colonoscopy. They proposed that the report should include lesion size, number, morphology, location, attenuation and recommendations for lesion surveillance. New research progress and clinical applications of CTC in CRC are reviewed in this article. In addition, the paper also brielfy touches upon technique, indications, contraindications, safety and risk of CTC.

Background and purpose:Tumor microenvironment plays an important role in the introduction of foreign factors that mediate tumor acquired resistance. The antitumor effects of many chemotherapeutic agents depend on the level of oxygen pressure (pO2) in tumor microenvironment. This study aimed to evaluate electron paramagnetic reso-nance (EPR)-based monitoring on an oxygen-enriched tumor microenvironment to increase chemotherapeutic sensitivity. Methods:MCF-7 cells were used to establish human breast cancer in nude mice. EPR was used to directly measure pO2 levelin vivo. Tumor tissues were collected, and mitochondrial activity was assayed on the basis of the kinetics of enzyme-catalyzed reactions. A laser Doppler monitor was used to detect regional blood flow. Tumor apoptotic rate was analyzed by flow cytometry.Results:The tumor volume decreased more evidently in the chemotherapy group with oxy-gen-enriched environment than that in the conventional chemotherapy group after the treatment was administered (P<0.01). After chemotherapy was completed, the apoptotic rate of tumor cells was significantly higher in the chemotherapy group with oxygen-enriched environment than that in the conventional chemotherapy group (P<0.001). This study examined the mechanism ofpO2 changes in tumor microenvironment: This was related to the change of the balance between the oxygen consumption and the regional blood flow in the tumor tissues after chemotherapy.Conclusion:Based on the characteristics ofpO2 changes in the tumor microenvironment after chemotherapy was completed, the selection of chemotherapy mode forthe treatment inpO2 peak time window improves the sensitivity of chemotherapy, which provides a new idea for individual-ized chemotherapy in clinical applications.

Objective To analyze the risk factors of microvascular invasion (MVI) in patients with hepatocellular carcinoma (HCC),and to establish a preoperative prediction model for MVI.Methods The clinical data of 159 patients with HCC from the First Hospital of Jilin University treated from January 2012 to December 2014 were retrospectively analyzed.There were 128 males and 31 females.Univariate and multivariate logistic regression analysis of factors influencing the presence of MVI in HCC patients were carried out.Independent risk factors were scored based on the β values of multivariate analysis.Receiver operating characteristics (ROC) curves were used to evaluate the predictive value of the scores for the risk factor for MVI.Results Univariate and multivariate logistic regression analyses showed that age ≥ 60 years (OR=0.263,95％ CI:0.112 ～ 0.614),tumor diameter ≥5 cm (OR=3.902,95％ CI:1.784 ～ 8.583),neutrophil to lymphocyte ratio (NLR) ≥ 1.83 (OR=2.414,95％ CI:1.065～5.472) and platelet to lymphocyte ratio (PLR) ≥ 72.30 (OR =2.578,95％ CI:1.068～ 6.223) were the influencing factors of MVI in patients with HCC (P＜0.05).The preoperative prediction model of MVI was established using the MVI independent risk factor scores.The area under the ROC curve was 0.793 (95％ CI:0.723～ 0.862).The optimal cutoff value for the presence of MVI was 2.75 points,and the sensitivity was 0.72 and the specificity was 0.78.The MVI positive rates of patients with risk scores of 0 to 1.5,2.0 to 3.5,and 4.0 to 5.0 were 18.6％,42.9％,and 78.3％,respectively.Conclusion Age,tumor diameter,NLR,and PLR were independent factors influencing MVI in patients with HCC.The preoperative model based on the independent risk factor scores can be used to predict the presence of MVI in HCC patients.