Differentiation Of Malignant And Benign Pulmonary Nodules With Dual-input Perfusion CT

Objective Lung blood is supplied by double circulation(pulmonary circulation and systemic circulation),the pulmonary circulation accounting for most part of the blood supply in normal physiological condition.For primary lung cancer,the composition proportion of its blood supply is different from normal lung tissue and pulmonary benign lesions.Through 320-slice CT perfusion Dual-input CT perfusion(DICTp)mode could distinguish two circulating blood supply of lesions,and malignant from benign solitary pulmonary nodules(SPNs).Materials and Methods A collection of Qingdao University Affiliated Hospital,June2014 to June 2016 with a solitary pulmonary nodule patients 69 cases,which active using DICTp mode based on the maximum slope method was adopted to quantify lung perfusion.Pulmonary trunk,descending aorta(representing bronchial artery)at hilus level were selected as dual-input arteries,and manually draw the region of interest within the lesion.The pulmonary flow(PF),bronchial flow(BF)and perfusion index [perfusion index,PI:PF/(PF+BF)] were calculated at following pre contrast CT value setting:-80 to 150HU(setting A)?-200 to 150HU(setting B)and-300 to 150HU(setting C).Three perfusion parameters measured respectively by two high qualification doctor,and diagnostic value of the perfusion parameters was calculated using the ROC curve analysis.Measure the influenced by the lower threshold of the CT value range setting in malignant lesions.Results Eight cases failed to get clear pathologic diagnosis because of lost data.Differences in perfusion parameters between malignant and benign tumours were assessed with histopathological diagnosis or follow-up visit as the gold standard,61 cases were chosen,of which 19 cases of non-malignant and malignant 42.Median PF was higher in malignant lesions than in benign lesions for all setting(42.5-84 verse41.8-55.6ml/min/100 ml,P<0.05).BF?PF had difference between malignant and benign lesions in setting A.Trying to analysing setting A,the final hemodynamics of malignant were generated by averaging: PF(42.59±23.15)ml/min/100 ml,BF(56.19±26.89)ml/min/100 ml,PI(24.56±20.86)%.And the non-malignant hemodynamics: PF(51.70±31.41)ml/min/100 ml,BF(38.40±19.92)ml/min/100 ml,PI(65.54±26.23)%.Then analysing ROC curve: the PI demonstrated the biggest difference between malignancy and benignancy.The area under the ROC curve was0.873,the largest of the three perfusion parameters,producing a sensitivity of 0.949,specificity of 0.57.9,positive likelihood ratio(+LR)of 6.25,and negative likelihood ratio(-LR)of 0.08 in identifying malignancy.Conclusions primary lung cancer was supplied by double blood circulation(pulmonary circulation and systemic circulation),with the dominance of systemic circulation.However,benign pulmonary lesions were predominantly supplied by pulmonary circulation.The PI derived from the dual-input maximum slope CT perfusion analysis is a valuable biomarker for identifying malignancy in SPNs.PI may be potentially useful for lung cancer treatment planning and forecasting the therapeutic effect of radiotherapy treatment.