Applicational Value Of Intravoxel Incoherent Motion Diffusion Weighted MR Imaging For Differentiation Diagnosis Of Central Type Carcinoma Of Lung And Lobar Collapse

Background The incidence and mortality of lung cancer are the highest in the current clinical common malignant tumor.According to the relevant statistics,in the world,the incidence and mortality of all malignant tumors,lung cancer accounted for the first.Among the female patients,the incidence and mortality of lung cancer are second,which is a serious threat to human life and health.In recent years,despite the rapid development of clinical medical technology and treatment,but the five year survival of patients with lung cancer has not been effectively improved.Central type lung cancer is a common type of lung cancer,and the lesions are less than three grade,and the pathological tissue is more than squamous cell carcinoma.According to the position of the tumor in the bronchus,the central type lung cancer can be divided into the tube,the tube wall and the shape of the tube,But whatever the type,in the process of the occurrence and development of lesions can lead to different degrees of bronchial stenosis or obstruction,resulting in local lobar or segmental atelectasis.The diagnosis and differential diagnosis of the lung caused by the central type of lung cancer is helpful to the clinical treatment plan.X-ray chest radiography is the main method for early diagnosis of pulmonary diseases,but the technical imaging ability is poor,can? t display the internal structure of the lesion,so can? t identify the cause of the disease.With the application of CT,especially the high resolution CT in clinical application,it provides a great help for the diagnosis of lung cancer and lung.However,because of the overlap of the imaging features of central type lung cancer and the lung caused by the disease and the obstruction caused by pulmonary benign lesions,the two lacks specificity,and the clinical diagnosis and differential diagnosis is not easy.In recent years,with the rapid development of magnetic resonance imaging,the imaging quality is high,the internal structure of the organization is clear,and the diagnosis and differential diagnosis of lung tumor and lung is also a new method.This article is to study the role of magnetic resonance imaging in the diagnosis and differential diagnosis of the central type lung cancer and pulmonary imaging.Objective To investigate the role of magnetic resonance imaging in the diagnosis of central type lung cancer,Incoherent motion intravoxel weighted diffusion Imaging MR(IVIM-DWI)in the diagnosis of central lung cancer and lung is studied in order to provide reference for clinical examination and diagnosis of the choice of the way.Method43 cases of central type lung cancer patients were selected and taken examination with SIEMENS Skyra 3.0T MAGNETOM smart magnetic resonance scanner.Patients were free of calm breathing,using T1 WI,T2WI and IVIM-DWI sequences,and in the end of breath trigger continuous scanning.Parameter settings: T1WI/TFE: TR10 ms,TE2.3ms,FOV375 mm,matrix256×375s,NSA1.T2WI/TSE: TR887 ms,TE80ms,FOV375 mm,matrix256375m,NSA1.IVIM-DWI: 0,50,100,200,400,600,800,1000s/mm2.Scan condition: TR899,FOV375 mm,matrix 256ch×256,NSA3.All the original data were transferred to the ADW4.5 GE workstation using Functool software and Omnikinetics(Healthcare GE)post processing platform,T2 image to find the location of the lesion,The calculated perfusion fraction(f),the true diffusion coefficient(D)and the related diffusion coefficient(D*),2 senior radiologists check T1 WI and T2 WI scan images and take image regions of interest(ROI)independently.The ROI was required to avoid the cystic degeneration,necrosis,hemorrhage and the region containing the normal blood vessels.2 levels of adjacent or coexisting of the obstructive pulmonary tissue and the central type of lung cancer were selected.In the presence of a lesion with an inhomogeneous component such as necrosis or void,At this point should be selected at least 3 round or oval,And as far as possible to avoid the uneven composition of the area as a ROI.For the composition of homogeneous lesions,ROI should avoid artifacts and vascular channels,Select the most uniform and signal lesions in the strongest region,And at least half of the maximum diameter of the lesions included above,Then calculate the mean value.The signal intensity compared to the adjacent bone(thoracic)as the reference signal,Analysis of the signal difference of obstructive pulmonary tissue and tumors in IVIM-DWI images,Distinguish and define the tumor range according to the difference of the two kinds of tissue signal intensity.Result1.The signal characteristics of obstructive lung tissue and tumor tissue: In 43 cases of retinoscopy,the T2 WI tumor tissues showed high signal intensity,and blocking lung atelectasis showed relatively low signal.The memory in the tumor necrotic area were found in 7 cases,Lung cancer and solid component clear boundaries in the image,The relative performance of low signal lesions of lung cancer,Signal strength difference is obvious.2 cases on the basis of IVIM-DWI image can not be identified the nature of lesions,1 cases with obstructive pneumonia were obstructive pulmonary tissue and tumor tissue showed high signal;The other 1 cases were small tumors,and growth along the bronchial wall,In the T2 WI image,the image is a high signal,and difficult to identify with pulmonary.2.Comparison of the parameters of obstructive pulmonary tissue and tumor tissue: In the images of 43 patients,each case was selected to calculate the parameters of 3 ROI.The results showed that the D value and D* value of the central lung cancer tissues were lower than those of the lung tissues,but the statistical analysis showed no significant difference(P>0.05).But in the comparison of the two F values,the difference was statistically significant(P<0.01).3.Diagnostic efficiency analysis: ROC curve analysis was performed on two kinds of lung tissue scanning images with different lung tissues as control.D,D* and F were 0.71,0.69 and 0.94 respectively,At this point,the D threshold is 0.75×10-3mm2/s,the D* threshold is 0.38×10-3mm2/s,and the f threshold is 38.42%.When the F value was 38.42%,the area under the curve(AUC)was the highest,which was 0.94,which could be considered to be the most effective for the diagnosis of lung cancer.At this time,the specificity of the diagnosis of lung cancer was 0.89,the sensitivity was 0.93,the positive predictive value was 0.92,and the negative predictive value was 0.89.Conclusion1.In magnetic resonance IVIM-DWI scanning image,The central type of lung cancer tissue in T2 WI showed a significant high signal,Blocking lung atelectasis showed relatively low signal in T2 WI.There is a big difference between two signal strength and easy to identify and delineate the scope of tumor tissue.2.There was no significant difference between the D value and D* value of the central type lung cancer and the lung tissue,Should be based on the F value of the two to identify.In spite of tumor and its adjacent tissue shape and structural factors such as local obstructive inflammation and tumor size may lead to some cases difficult to identify,But overall,Magnetic resonance IVIM-DWI has great value in the identification of central type lung cancer and lung tissue.