Preliminary Application Of Spectral CT In Differential Diagnosis Of Squamous Cell Carcinoma And Adenocarcinoma Of The Esophagogastric Junction

Objective:To evaluate the value of spectral CT imaging for the differential diagnosis of squamous cell carcinoma(SQCC)and adenocarcinoma(ADC)of the esophagogastric junction.Methods:45 patients with a mass in the esophagogastric junction proved by pathology underwent enhanced scan with spectral CT,including 20 cases of SQCC and 25 cases of ADC.Iodineconcentration(IC),water concentration(WC),effective atomic number(Eff-Z)and spectral curve slope(?HU)of arterial phase(AP)and venous phase(VP)in the region of interest(ROI)of the mass were measured with gemstone spectral imaging post-processing software.The independent samples t test was used to compare the quantitative parameters above between two groups on the premise of satisfying normal distribution.Draw ROC curves for the parameters which showed statistical differences and use area under the curve(AUC)to measure and compare their respective differential diagnostic performance as well as the best threshold value.Results:In AP,the average IC?Eff-Z and ?HU of ADC were(1.75±0.40)mg/mL,8.65±0.22 and 3.33±0.74,respectively;The corresponding parameters of SQCC were(1.40±0.35)mg/mL,8.50±0.20 and 2.71±0.66,respectively.These parameters of ADC were significantly higher than SQCC(t =-2.833,-2.879,-2.678,P<0.05).In VP,the average IC ? Eff-Z and ?HU of ADC were(2.17 ±0.23)mg/mL,8.87 ± 0.11 and 4.10 ± 0.44,respectively;The corresponding parameters of SQCC were(1.67 ± 0.20)mg/mL,8.60 ± 0.11 and 3.19 ± 0.41,respectively.The difference between ADC and SQCC was statistically significant(t=-6.963,-7.218,-6.521,P<0.05).Whilethe average WCin AP were(1016.04 ± 7.80)mg/mL and(1020.40 ± 10.43)mg/mLfor ADC and SQCC respectively,(1019.94 ± 6.51)mg/mL and(1020.23 ± 10.09)mg/mL in VP accordingly.No difference between the two groups were found(t =1.435,0.104,P>0.05).ROC curve analysis showed that IC?Eff-Z and?HU in VP had betterdifferential diagnostic performances than IC ? Eff-Z and?HU in AP,especially Eff-Z inVP.The AUC for it was 0.97.Using 8.72 as a threshold value,its sensitivity and specificity for diagnosis were 88.9% and 94.7%,respectively.Conclusion:Multi-parameters quantitative analysis with spectral CT could be useful in the differential diagnosis of SQCC and ADC of the esophagogastric junction.