Value Of Real-time Shear Wave Elastography In Differential Diagnosis Of Benign And Malignant Peripheral Lung Masses

Objective: To explore the value of shear wave elasticity(SWE)technology in the differential diagnosis of benign and malignant lesions of peripheral pulmonary masses,so as to provide important imaging tools for early clinical diagnosis and treatment of lung cancer.Methods: 1.112 patients admitted to the department of respiratory and cardiothoracic surgery of our hospital from November 2017 to October 2018 who were found to have a single peripheral pulmonary mass by X-ray or chest CT examination were selected as study subjects.Their names,ages and other general parameters were recorded.The pathological results obtained by puncture or surgery were regarded as gold standard to group these patients into benign group and malignant group and the malignant group was further divided into squamous cell carcinoma subgroup,adenocarcinoma subgroup,small cell carcinoma subgroup and other groups.2.All patients were examined by conventional ultrasound and SWE.The location,shape,size,number,internal echo and the relationship with surrounding tissue of lung masses were observed in two-dimensional ultrasound mode.Maximum diameter line of the lesions were measured.The internal and peripheral blood flow characteristics of the lesions were observed by color doppler.The depth of lesions,the maximum value of Young’s modulus—Emax and the mean value of Young’s modulus—Emean were measured by restarting SWE technology,and the images were stored finally.3.The differences of Emax and the Emean between benign and malignant groups and among different pathological type subgroups of malignant groups(squamous cell carcinoma subgroup,adenocarcinoma subgroup and small cell carcinoma subgroup)were statistically analyzed.The ROC curve was drawn to obtains the best cutoff value,the area under the curve,the sensitivity,specificity,positive predictive value,and negative predictive value of identifying of benign and malignant peripheral pulmonary masses.Results 1.Pathological results: Of the 112 lesions,47 were benign including 37 cases of inflammatory cell infiltration,5 cases of tuberculosis and 5 cases of schwannoma.There were 65 cases of malignant lesions including 20 cases of lung adenocarcinoma,24 cases of lung squamous cell carcinoma,17 cases of small cell lung cancer,2 cases of metastatic lung cancer,and 2 cases of large cell lung cancer.2.The BMI values of the benign group and the malignant group were 21.72± 2.63 and 21.20±2.51,respectively.The measured depth of pulmonary masses of the benign group and the malignant group was 4.51±1.12 cm and 4.82±1.33 cm,respectively.And there was no significant difference between the two groups(both P>0.05)in the BMI values and the measured depth of pulmonary masses.The maximum diameter of pulmonary masses in the benign group and the malignant group were 4.23± 1.43 cm and 5.73±1.91 cm,respectively,The masses in the malignant group were larger than those in the benign group(P<0.05).The Emax and Emean in the malignant group were 13.20±10.85 kpa and 8.40±0.52 kpa,respectively.The Emax and Emean in the benign group were 9.45±0.73 kpa and 5.27±0.53 kpa,respectively.The Emax and Emean in the malignant group were larger than that of the benign group(P<0.05).The Emax and Emean of small cell carcinoma subgroup are the highest in the malignant groups including squamous cell carcinoma subgroup,adenocarcinoma subgroup,small cell carcinoma subgroup,but there was no statistical difference among the three groups(P>0.05).3.According to the ROC curve,the cut-off values for differentiating benign and malignant peripheral pulmonary masses were 10.35 kpa and 5.85 kpa,respectively.The area under the curve,sensitivity,specificity,positive predictive value and negative predictive value for the diagnosis of malignant lesions were 0.74,74.36%,72.22%,85.29%,57.52% and 0.80,81.58%,80.78%,89.57%,67.67%,respectively.Conclusion: 1.SWE technology makes up for the deficiency of conventional ultrasound,and can well evaluate the elastic properties of peripheral pulmonary masses,providing an important imaging diagnostic method for the benign and malignant evaluation of peripheral pulmonary masses.2.Taking Emean= 5.85 kpa as the cut-off value of identifying of benign and malignant lesions,the sensitivity,specificity,positive predictive value and negative predictive value of the diagnosis were all higher than that of Emax,indicating higher diagnostic efficiency than Emax.