2019/11/26,.,1,Multi-detector spiral CT study of the relationshipsbetween pulmonary ground-glass nodules and blood vessels,Eur Radiol (2013) 23:32713277,2019/11/26,.,2,Abstract,Objective : To investigate the relationships between pulmo-nary ground-glass nodules (GGN) and blood vessels and their diagnostic values in differentiating GGNs. Conclusion : Different GGNs have different relationships with vessels. Understanding and recognising characteristic GGN-vessel relationships may help identify which GGNs are more likely to be malignant.,2019/11/26,.,3,Key Points,Multi-detector CT offers new information about ground- glass nodules. Different types of ground-glass nodules have different relationships with vessels. This may help identify which ground-glass nodules are likely to be malignant.,2019/11/26,.,4,Introduction,With the extensive acceptance of low-dose multi-detector spiral CT in lung cancer screening , the number of detected GGNs or focal ground-glass opacities (fGGOs) has dramatically increased. GGNs can result from neoplasms, such as pulmonary adenocarcinoma, or benign diseases, such as focal fibrosis, inflammation or alveolar haemorrhage.,2019/11/26,.,5,In addition, pre-invasive abnormalities, including atypical adenomatous hyperplasia (AAH) and adenocarcinoma in situ (AIS). It has been reported that the proportion of malignancy in GGNs is higher than in solid pulmonary nodules (SPNs) and the majority of malignant GGNs are adenocarcinoma . Due to imaging resemblance, however, it is extremely challenging to differentiate malignant GGNs from the aforementioned benign counterparts.,2019/11/26,.,6,Accurate differential diagnosis of GGNs will assist physicians to make treatment decisions and improve treatment outcomes and prognosis. Several investigators have suggested that analysis of relationships between SPNs and surrounding vessels can help predict the likelihood of malignancy in such nodules. The relationship between GGNs and blood vessels remains unknown. Whether this relationship can be utilised to facilitate the diagnosis of malignant GGNs is a worthy of investigation.,2019/11/26,.,7,Materials and methods,Patients The imaging data of patients with pulmonary GGNs receiving thin-section multi-detector CT examination at our hospital in January 2011 through November 2012 were retrospectively reviewed. All lesions were solitary and most of them(104/108) surgically resected within 2 weeks after CT scanning.,2019/11/26,.,8,Inclusion criteria The GGN size was less than 3cm in the largest dimension. ground-glass opacity (GGO) comprised more than 50 % of the area of the lesion on CT. -An area of over 50 % GGO was set as the cutoff value to exclude solid/semi-solid lesions. -Although solid nodules frequently had GGO components around their margin, probably representing surrounding oedema or merely poor aeration of the surrounding lung tissues due to compression or retraction by nodules, these nodules had already been well investigated using CT and therefore were not the study objects,2019/11/26,.,9,Ultimately, 108 patients were enrolled into this study, including 38 males and 70 females with mean age of 58.1812.89 years (range, 22 to 79 years). 43 patients were asymptomatic, 28 had respiratory symptoms, and 37 had lung cancer risk factors, such as smoking and family history.,2019/11/26,.,10,According to pathological findings, GGNs were divided into three groups: Benign disease group (10 cases), including four nodules diagnosed with a combination of clinical symptoms and imaging presentations (nodules disappeared or gradually reduced in size on multiple follow-up CT imaging) and six nodules confirmed by pathological examination (1 case of sclerosing haemangioma and 5 cases of chronic inflammation). (2) Preinvasive disease group (24 cases), including 7 AAHs and 17 AISs.,2019/11/26,.,11,(3) the invasive adenocarcinoma group (74 cases), confirmed pathologically, there were 39 non-mucinous minimally invasive adenocarcinomas (MIA) and 35 invasive adenocarcinomas (IAC; specifically, 13 lepidic predominant adenocarcinomas; 19 acinus-predominant adenocarcinomas; 2 papillary-predominant adenocarcinomas and 1 solid predominant with mucin粘蛋白 production).,2019/11/26,.,12,CT imaging analysis,protocol parameters: 0.625-mm section width with a 0.625-mm reconstruction interval, pitch of 0.984, 120 kV and 250 mA. All images were reviewed with a high-resolution , 2,0481,560pixel ,standard lung window (ww , 1,500 HU; wl, -500 HU) and mediastinal window (ww, 350 HU; wl, 50 HU) GGNs can be further subdivided into mixed ground-glass nodules (mGGNs) and pure ground-glass nodules (pGGNs) . The percentage of the GGO component was calculated as follows: (DGGO-D)/ DGGO 100, where DGGO is the largest diameter of the entire lesion and D is the largest diameter of the solid component within the lesion.,2019/11/26,.,13,Blood vessel analysis was performed in terms of vascular morphology and vascular relationships with GGN l