[Clinical value of spectral CT imaging in preoperative evaluation of pathological grading of esophageal squamous cell carcinoma].

Objective: To investigate the value of spectral computed tomography quantitative parameters in the assessment of pathological grade of esophageal squamous cell carcinoma before operation. Methods: The imaging findings of 52 patients with confirmed esophageal squamous cell carcinoma by surgery and pathology were prospectively analyzed in Henan Provincial People's Hospital from June 2016 to May 2017.There were 43 males and 9 females, aged 49-76 years, with an average age of (66±8) years.All the patients were divided into three groups based on the pathological finding: well-differentiated group ( n =12), moderately-differentiated group ( n =20), poorly-differentiated group ( n =20). All the patients received chest plain scan and double phase enhanced scan of gemstone spectral computed tomography.The enhancement attenuation (HU), the average of the slope of the spectral Hounsfield Unit curve (λ(HU)), normalized iodine concentration (NIC), normalized effective atomic number (Z(eff-a)) were measured and calculated.The difference in HU, λ(HU), NIC, Z(eff-a) among different grades were statistically analyzed.The receiver operating characteristic (ROC) curve was used to evaluate the diagnostic efficiency of single and combined parameters in the differentiation of poorly-differentiated and well-moderately differentiated esophageal squamous cell carcinoma. Results: There were significant differences in HU, λ(HU), NIC, Z(eff-a) among different pathological grading of the esophageal squamous cell carcinoma in arterial phase and venous phase ( F =4.496-9.056, H =23.204, 20.724, all P <0.05). The best single parameter to differentiate poorly-differentiated from well-moderately differentiated esophageal squamous cell carcinoma was NIC in arterial phase with areas under the ROC curve (AUC), the cutoff value, sensitivity, specificity, accuracy of 0.860, 0.197, 65.0%, 96.9%, 84.6%, respectively; the best combination of parameters was HU+ NIC+ λ(HU) in arterial phase with AUC, the threshold of predicted probability, sensitivity, specificity, accuracy of 0.913, 0.380, 85.0%, 81.3%, 82.7%, respectively. Conclusion: Gemstone spectral imaging quantitative parameters can be used to evaluate the pathological grading of esophageal squamous cell carcinoma, the NIC and HU+ NIC+ λ(HU) in arterial phase have the highest differential diagnostic efficiency.