The Application Value Of Energy Spectral Ct Imaging In The Diagnosis And Assessing The Degree Of Differentiation Of Colorectal Cancer

Objective: To investigate the application value of energy spectral CT imaging in the diagnosis and assessing the degree of differentiation of colorectal cancer.Materials and Methods:(1)31 patients with pathologically confirmed as colorectal cancer and 20 patients with non-intestinal lesions were enrolled in this study.All patients underwent CT double-phase contrast-enhanced scan and acquired arterial and venous phase plain scan and 40 Ke V-140 Ke V single-energy images.Arterial and venous phases reconstructed images’ slope(K value),atomic number(Z value),normalized atomic value(normalized Z value),iodine concentration(IC)and normalized iodine concentration(NIC)were measured in the lesions’ intestinal wall of patients with colorectal cancer(experimental group),the lesions’ distal normal intestinal wall(control group 1)and the intestinal wall of patients with non-intestinal lesions(control group2).The above parameters were compared between experimental group and control groups with ANOVA analysis.The area under the curve(AUC)of each parameter in the diagnosis of colorectal cancer was calculated and compared with the receiver operating characteristic(ROC)curve to evaluate its diagnostic efficacy and choose the best diagnostic threshold.(2)The CT value of the lesions’ intestinal wall and the lesions’ distal normal intestinal wall and subcutaneous fat SD were measure in arterial and venous phase plain scan and different single-energy reconstructed images.The standard deviation(SD)was automatic generation.The contrast-to-noise ratio(CNR)was calculated,respectively.CNR at different single-energy of arterial and venous phase were compared with ANOVA analysis to get higher CNR.(3)According to pathology,it was divided into low-grade cancer group(23 cases)and high-grade cancer group(8 cases).Arterial and venous phases reconstructed images’ K value,Z value,standardized Z value,IC and NIC were measured and compared between two groups to assure whether they were significantly different.The AUC for assessing the degree of colorectal cancer’s differentiation was calculated and compared with the ROC curve,and the best diagnostic threshold was selected.Results :(1)There were significant differences in arterial and venous phases reconstructed images’ K value,Z value,normalized Z value,IC and NIC between experimental group and control group 1、2(P <0.05),and the AUC were 0.875、0.864、0.782、0.868、0.881、0.955、0.935、0.797、0.950、0.926,and when the ROCAUC of the venous phase’s K value was 0.955 and the cutoff value was 1.16,the sensitivity and specificity of the diagnosis of colorectal cancer were 87.1 and 96.1,respectively.There was no significant difference in arterial and venous phases reconstructed images’ K value,Z value,normalized Z value,IC and NIC between control group 1 and control group2(P> 0.05).(2)ANOVA analysis of CNR at 40 Ke V,70 Ke V and 100 Ke V in arterial and venous phases reconstructed images showed that 40 Ke V reconstructed image’s CNR was the highest in three.(3)There were 23 cases(high and moderate differentiation)and 8cases(poor differentiation and undifferentiation).There was no significant difference in arterial and venous phases reconstructed images’ K value,Z value,stan-dardized Z value,IC and NIC between two groups(P> 0.05).Conclusions:(1)The multi-parameter quantitative analysis of energy spectral CT has definite value in the diagnosis of colorectal cancer.(2)Energy spectral CT in evaluation of colorectal cancer lesions has the best CNR at 40 Ke V reconstructed image.(3)The multi-parametrer quantitative analysis of energy spectral CT has no definite value in assessing the degree of colorectal cancer’s differentiation.