Preliminary application of spectral CT in differential diagnosis of squamous cell carcinoma and adenocarcinoma of the esophagogastric junction / 中华放射学杂志

ABSTRACT

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 Forty-five 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. Iodine concentration (IC) , water concentration (WC) , effective atomic number (Eff-Z) and spectral curve slope (λHU) of arterial phase (AP) and venous phase (VP) in the 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. ROC curves were drawn for the parameters which showed statistical differences and area under the curve (AUC) was used to measure and compare their respective differential diagnostic performance as well as the best threshold value. Results In AP,the average IC, Eff-Z, andλHU 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 that of SQCC (t=-2.833,-2.879,-2.678;P<0.05) . In VP, the average IC, Eff-Z, and λHU 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). For the average WC, No difference between the two groups in AP and VP was found. ROC curve analysis showed that IC, Eff-Z, andλHU in VP had better differential diagnostic performances than IC, Eff-Z, and λHU in AP, especially Eff-Z in VP. The AUC for it was 0.97. Using 8.72 as a threshold value, the 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.