Correlative Study Of Dual-source CT Perfusion Imaging And Micro-vascular Composition In Solitary Pulmonary Nodules

Objective: To study the correlation of dual-source CT perfusion imaging and luminal vascular parameters of solitary pulmonary nodules(SPN)and explore the value of the dual-source CT perfusion imaging in the diagnosis and differential diagnosis of solitary pulmonary nodules.Methods: 65 patients with solitary pulmonary nodule founded by routine CT scanning,then underwent CT perfusion imaging successfully pre-operation with the dual-source CT and got the final diagnosis by pathology in Affiliated Hospital of Zunyi Medical College from January 2015 to September 2016 were collected.The cases including 43 males and 22 females,aged from 23 to 74 years,with a mean age of 51.27 years.All perfusion data were transmitted to workstation(Siemens Syngo Multimodality workplace),then analyzed with perfusion software(VPCT body)to obtain time-density curve(TDC)and perfusion parameters,such as blood flow(BF),blood volume(BV),mean transit time(MTT),permeability surface(PMB)as well as their corresponding perfusion pseudo-color images.The PV-9000 2-Step method immunohistochemical detection system was used to stain the 65 cases specimens.Then luminal vascular number(LVN),luminal vascular area(LVA)and luminal vascular perimeter(LVP)were counted.The cases were divided into three groups that malignant group(21 cases of adenocarcinoma,12 cases of squamous carcinoma,2cases of large cell neuroendocrine carcinoma,1 case of adenosquamous carcinoma,1 case of small cell carcinoma,1 case of carcinoid tumor and 1 case of sarcomatoid carcinoma),benign group(9 cases of tuberculoma,1 case of aspergillosis,1 case of inflammatory myofibroblastic tumor,1 case of sclerosing hemangioma,1 case of neurofibroma and 1 case of hamartoma)and inflammatory group(12 cases)according to their pathological results.The difference of dual-source CT perfusion parameters and luminal vascular parameters among the three groups was observed.Correlation analysis was used to study the relationship between dual-source CT perfusion parameters and vascular parameters of SPN.Then ROC curve was used to analyze the diagnosis effectiveness of dual-source CT perfusion parameters in diagnosing malignant SPN.Results:(1)TDC:Malignant SPN mainly showedⅠtype curve,namely rapid rise and immediate decline type,the descending part with the platform,accounting for74%(29/39).Inflammatory SPN mainly showedⅡtype curve,namely rapid rise and slow decline type,accounting for 75%(9/12).Benign SPN mainly showed Ⅲ type curve,namely a slight upward trend and fluctuations in a certain range,accounting for86%(12/14).(2)BF,BV,LVN,LVA and LVP values of malignant and inflammatory group were significantly higher than those of benign group,the significant differences had statistical significance(P<0.05).There was significant difference in PMB,LVA and LVP between malignant group and inflammatory group(P<0.05);there was no significant difference in BF,BV and LVN between malignant group and inflammatory group(P>0.05).PMB of malignant group was significantly higher than that of benign group,the difference was statistically significant(P<0.05),but there was no significant difference between benign group and inflammatory group(P>0.05).There was no significant differences in MTT among the three groups(P>0.05).(3)Correlation analysis showed that LVN,LVA and LVP had positively correlated with BF,BV;LVA,LVP had positively correlated with PMB,while LVN,LVA and LVP there were no correlation with MTT.(4)When regard BF≥56 ml/100ml/min as a cutoff point to predict malignant SPN,the sensitivity was 85%,the specificity was54%;When regard BV ≥ 6.34ml/100ml/min as a cutoff point to predict malignant SPN,the sensitivity was 82%,the specificity was 54%;When regard PMB ≥8.88ml/100ml/min as a cutoff point to predict malignant SPN,the sensitivity was100%,the specificity was 50%;When BF≥60ml/100ml/min,BV≥6.59 ml/100 ml and PMB≥9.9ml/100ml/min are used for diagnosis together,the sensitivity was 82%,the specificity was 62%.Conclusion: There were significant differences in the micro-vascular composition among benign,inflammatory and malignant SPN.Dual source CT perfusion parameters have relationship with luminal vascular parameters(LVN、LVA、LVP)and they can be used as important indexes to non-invasively evaluate tumor angiogenesis.Dual source CT perfusion imaging is conducive to the diagnosis and differential diagnosis of SPN.