A Study On The Value Of MSCT In Diagnosis And Differential Diagnosis Of Intrapulmonary Lymph Nodes With Related Small Nodules

Objective: Discuss of the characteristics of multi-slice spiral CT(MSCT)features in intrapulmonary lymph nodes(IPLNs),Analysis in IPLNs and other nodes in MSCT imaging features of micro and small nodular lesions of the differences and similarities,so as to improve the clinical of IPLNs diagnostic accuracy.Materials and Methods: Analyzed retrospectively from January 2013 to January 2016,30 patients of intrapulmonary lymph nodes which confirmed by biopsy or surgical pathology(15 males and 15 females),a total of 39 lesions,aged between 38 and 74years(median=58 years).At the same time to collected 70 cases of small pulmonary solid nodules(<1 cm)image data(32 male,38 female),aged between 34 and 80years(median=59 years),according to the pathological types divided into four groups:lung cancer group(31 cases),pneumonia group(19 cases),pulmonary tuberculosis group(9 cases),pulmonary hamartoma group(n=11).We conducted a comparative analysis of the imaging features and pathologic results of IPLNs.Nodules imaging signs include: morphology(round/ oval shape,irregular shape),lung tumor interface(clear,fuzzy),edge(lobulation and burr sign),internal structure(vacuole sign,air bronchogram),relationship with adjacent vessels traveling,adjacent to the structure change(pleural indentation,linear density),the distance from the pleura,etc.All patients underwent MSCT scan before operation and all the images were reconstructed with MPR and standard thin layers reconstruction.All data were analyzed by SPSS statistics software(version 17.0)and the consistency of the data from the two observers was tested using the correlation coefficient(correlation coefficients intra-class,ICC);The patient’s age,diameter,CT value using single factor variance analysis.and Scheffe test for groups;On the analysis of nodule location and MSCT imaging features of using the Chi-square test or the Fisher’s exact probability test.Using ROC analysis of CT value in IPLNs and other four groups of diagnostic sensitivity,specificity and determine the critical value.The P value is less than 0.05 was the difference has statistical significance.Results:1.Clinical features of IPLNs: The collection of 30 cases of patients;Clinical symptoms:4 had cough,2 patients with paroxysmal chest pain,the remaining for accidental discovery.previous history,2 patients had a history of prior malignancy;8patients had a history of smoking(minimum of 20 pack-years);Before operation,5 cases were misdiagnosed as lung cancer,2 cases of pulmonary tuberculosis.After confirmed,IPLNs were associated with lung cancer in 13 cases,and 1 cases accompanied with pulmonary hemangioma.2.The MSCT Imaging manifestations of IPLNs:Detected nodules 39,(1)Diameter and density;the diameters of the IPLNs ranged from 3.0 to 10 mm,and the mean diameter was 6.1mm.The maximum level average CT value is 53.3Hu.(2)Place and distance with the pleura: 11 cases of IPLNs were solitary and 5 cases were multiple.After operation,all the pathological changes were in the lymph nodes,partly visible carbon dust.28 cases in the right lobe,11 in left lobe,a total of 25 under the double lung;Mostly located in the pleural,30 IPLNs were located the pleura(less than 10 mm).4cases is located in the oblique fissure and the horizontal cleft,connected with inclined crack.(3)Morphological: Nodule shape was round or oval in 31,triangular or trapezoidal in 4 cases;5 nodular visible lobulation,3 nodular visible short and thin spiculation sign,7 nodular showed pleural indentation sign,linear density shadow was seen in 24 nodules..All nodules were not found vessel convergence sign,however,the normal small blood vessels in the lungs can be seen in 17 nodules.14 Small pulmonary nodules located in vascular bifurcation;3.IPLNs group compared with the other four groups: IPLNs group with other four groups there was no statistically significant difference in age and gender,IPLNs group and the other four groups in the diameter and CT value difference was statistically significant.IPLNs and lung cancer group in the CT value,the distance from the pleura,and i mage characteristics was statistically significant.(P < 0.05)IPLNs with pneumonia group in shape,boundary,burr sign,blood vessels,cluster,linear density,and pleural,the distance from the pleura has statistical significance.(P<0.05)IPLNs with tuberculosis group difference was statistically significant on the parts of the nodule,boundary,the burr,pleural sag,linear density shadow.(P < 0.05)IPLNs with pulmonary hamartoma group there are differences between CT value and the linear density(P <0.05).ROC curve analysis to 30.5Hu threshold differentiate IPLNs and lung hamartoma group sensitivity was 90.5%,the specificity was 80.0%,the area under the curve(AUC)value was 0.910 to 28.5Hu critical values for the identification of intrapulmonary lymph node and lung cancer group of sensitivity was 95.2% and the specificity was 75% and AUC values for 0.872.Conclusion:1.The application of MSCT scanning technology of post-processing,make the lesions intuitive emerge,The past can not identify the intrapulmonary lymph node to diagnosis.2.Most of the IPLNs Within the lung benign nodules imaging characteristics,Circular or elliptic,border and clear,Occurs in the lower lobe of the lung pleura less then10 mm,The adjacent vessels were normal,nodules located in the vascular bifurcation,In addition,higher density and linear density of the nodules are more characteristic of Identify in lymph nodes and lungs in other classes lungs nodular lesions.