| Objective: To explore the value of spectral parameters in staging,grading and lymph node metastasis of colorectal cancer(CRC)by Revolution spectral imaging,providing a new way for the clinical diagnosis and relevant treatment of colorectal cancer.Methods: 76 patients with colorectal cancer confirmed by colonoscopy or pathology were enrolled.All patients were performed by GSI spectral CT plain and dual phase scan before surgery.The relevant single energy images were obtained by GSI viewer software Protocols general plate.Delineating the appropriate region of interest(ROI)in the lesions,and measuring and calculating the iodine concentration(IC),water concentration(WC),effective atomic number(Eff-Z),normalized iodine concentration(NIC)and the slope of spectral curve(K).Step1 : analyzing the diagnostic efficiency and the consistency with pathological staging by combining the obtained single energy image with pathological T staging standard;Step2:dividing 76 patients into low differentiation group and middle high differentiation group according to the pathological results,comparing the spectral parameters of the two groups,the statistically significant parameters were used for Receiver operating characteristic(ROC)to assess its diagnostic ability and find out the best diagnostic threshold.Step3:76 patients were divided into lymph node metastasis group(N1-2)and non lymph node metastasis group(N0).Comparing the spectral parameters of the two groups,the diagnostic ability of the statistically significant parameters was evaluated by receiver operating characteristic curve(ROC)to find out the best diagnostic threshold.Results: 1.Compared with pathological T staging and single energy image preoperative T staging: the accuracy of preoperative T staging,T1-2,T3 and T4 was 84.21%,92.11%,84.21% and 92.11% respectively.By consistency test,we can get the corresponding kappa = 0.73(P < 0.05);Spearman correlation analysis between spectral CT and pathological T stage: r = 0.824(P < 0.05).2.Comparison of multi parameter imaging of energy spectrum CT in preoperative diagnosis of colorectal cancer differentiation: among 76 patients,51 cases were in high differentiation group and 25 cases were in low differentiation group.The values of IC,NIC and K in arterial phase of low differentiation group were17.54 ± 2.81(μ g / ml),0.22 ± 0.73 and 2.02 ± 0.44 respectively,which were higher than those in middle-high differentiation group,and the corresponding values were 15.35 ± 3.54(μ g / ml),0.17 ± 0.05 and 1.80 ± 0.40 respectively,The values of IC,NIC and K in venous phase of low differentiation group were20.52 ± 2.56(μ g / ml),0.66 ± 0.81 and 2.39 ± 0.30 respectively,which were higher than those of middle-high differentiation group.The corresponding values were 17.79 ± 2.54(μ g / ml),0.50 ± 0.11 and 2.11 ± 0.40 respectively,and there was statistical significance between the two groups(P < 0.05).In ROC curve comparison,the areas under the curve of IC,NIC and K in arterial phase were 0.76,0.75 and 0.70 respectively,and the optimal thresholds were 16.11,0.19 and 2.05 respectively;the areas under the curve of IC,NIC and K in venous phase were 0.78,0.86 and 0.72 respectively,and the optimal thresholds were18.31,0.56 and 2.07 respectively.The diagnostic efficiency of NIC in venous phase was better than other indicators.3.Comparison of spectral CT multi parameter imaging in preoperative diagnosis of colorectal cancer with or without lymph node metastasis: there were 33 cases in lymph node metastasis group(n1-2)and 43 cases in non lymph node metastasis group(N0).The IC,NIC,eff-z and K values of arterial phase colorectal cancer in n1-2 group were17.54 ± 2.81(μ g / ml),0.22 ± 0.73,8.55 ± 0.21 and 2.02 ± 0.44,respectively.The corresponding four spectral parameters of arterial phase colorectal cancer in N0 group were 15.35 ± 3.54(μ g / ml),0.17 ± 0.05,8.51 ± 0.21 and 1.80 ± 0.40,respectively.The difference was statistically significant(P < 0.05).The IC,NIC,eff-z and K values of venous phase colorectal cancer in n1-2 group were significantly lower than those in n1-2 group The corresponding values were20.58 ± 2.49(μ g / ml),0.64 ± 0.10,8.75 ± 0.22 and 2.44 ± 0.37 in N0 group.The corresponding values of the above spectral parameters were 17.22 ± 2.16(μg / ml),0.48 ± 0.09,8.63 ± 0.13 and 1.98 ± 0.28 in N0 group,respectively.The difference was statistically significant(P < 0.05).The area under the curve of IC,NIC,eff-z and K in arterial phase was 0.81,0.86,0.69 and 0.73 respectively,and the diagnostic threshold was 16.11,0.18,8.56 and 1.93 respectively;The areas under the curve of IC,NIC,eff-z and K in venous phase were 0.84,0.89,0.68 and 0.86,respectively.The diagnostic thresholds were 18.31,0.55,8.76 and 2.10,respectively.The highest diagnostic efficiency was in arterial phase NIC and venous phase NIC.Conclusion:1.Spectral CT single energy imaging has high accuracy in preoperative T staging of colorectal cancer,and has high consistency with pathological T staging;2.IC,NIC and K are of great value in the diagnosis of preoperative differentiation of colorectal cancer;3.IC,NIC,eff-z,K have a certain predictive value for preoperative lymph node metastasis of colorectal cancer. |
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