Study On Arrive Time In The Diagnosis Of Peripheral Lung Lesions

Objectives:1.To explore the value of the quantitative parameters of time-intensity curve(TIC)acquired by contrast-enhanced ultrasound(CEUS)in differential diagnosis of peripheral lung lesions.2.To investigate the diagnostic value of the arrival time difference between lesions and its adjacent gas-containing lung tissue on the real-time CEUS combined with the comparative observation method of peripheral lung lesions.3.To compare the diagnostic value of the real-time CEUS combined with the comparative observation method and the conventional initial arrive time diagnostic criteria in differential diagnosis of peripheral lung lesions.Methods:1.95 patients detected by chest CT and visualized by ultrasound were enrolled,the dynamic contrast datas were stored after CEUS examinations.All the pathological specimens were obtained by surgical removal or percutaneous ultrasound-guided biopsy.95 peripheral lung lesions were classified into the malignant group and the benign group based on the histopathologic results.Using the instrument’s built-in graphing and analysis software,a time-intensity curve was constructed based on a chosen region of interest within the lesion where enhancement was the most obvious.Commonly used perfusion indicators in CEUS,such as AT,time-to-peak(TTP),Rise time(RT)and peak intensity(PI),were obtained from the time-intensity curve.2.The arrival time of contrast agent in the peripheral lung lesion with that in adjacent lung tissue and the time difference were calculated and recorded respectively,referred to as a real-time comparative observation method.The ROC curve was plotted to calculate the area under the curve and the optimum cut-off point.3.The diagnostic rates in the differential diagnosis of peripheral lung lesions were calculated by those of the conventional diagnostic criteria based on the initial arrival time≥ 10 s.4.The sensitivity,specificity,positive predictive value,negative predictive value and diagnostic accuracy of the two diagnostic criteria were compared.Results:1.There were 60 male and 35 female among 95 cases of peripheral lung lesions,the mean age was 59.1±12.6 years old(rang 24-81).The longest diameter of the lesion was in the range of 3.4-12.4 cm(mean 6.4±3.3 cm).Of all 95 lesions,42 cases were located in the left lobe,53 cases were located in the right lobe.64 were diagnosed according to surgical remove and the 31 according to puncture biopsy specimens.The histopathologic results of all 95 peripheral lung lesions were as follows: 55 malignant tumors(19 squamous cell carcinomas,14 adenocarcinoma cell carcinomas,11 small cell lung cancer,3 large cell carcinomas,8 neuroendocrine cancer),40 benign lesions(28 inflammatory tissue,7 tuberculosis,3 inflammatory pseudotumor,2 hamartoma).2.AT was significantly shorter in patients with benign lesions than in those with malignant tumors(p < 0.05),whereas no significant differences in TTP,RT or PI were seen among those with various lung lesions.3.The results of the statistical analysis indicated that the lesion arrival time and lesion-lung difference in the malignant group were significantly longer than those in the benign group(p < 0.05).The lung lesion arrival times showed no significant differences between the malignant and benign groups(p > 0.05).According to the receiver operating characteristic curve,the lesion arrival time,lesion-lung difference were all able to significantly differentiate malignant lesions from benign lung lesions.Among them,the area under the curve for the lesion-lung arrival time exceeded 0.9 and had the higher diagnostic value.The best cut-off point for the lesion-lung difference determined by the Youden index was 2.5 seconds and its sensitivity,specificity,and accuracy were as high as 96.4%,97.5%,and96.8%,respectively.4.Based on the histopathologic results,the sensitivity,specificity,and accuracy of the conventional criterion were 72.7%,82.5%,and 85.1%,respectively.5.The diagnostic accuracy of the new criterion using the real-time comparative observation method was significantly higher than that obtained by using a lesion initial arrival time of 10 seconds or higher.Conclusion:1.The quantitative parameters AT obtained by CEUS time-intensity curve can help diagnose peripheral lung lesions.2.The new diagnostic criterion using the real-time comparative observation method determined in this study was as follows: if the arrival time difference between the lesion and lung tissue was 2.5 seconds or longer,the lesion was likely to be malignant.By contrast,if the value was shorter than 2.5 seconds,the lesion tended to be benign.3.The diagnostic accuracy of the new criterion using the real-time comparative observation method was higher than that obtained by the conventional initial arrive time diagnostic criteria.