Objective To discuss the pathological classification and lesion's inner imaging features of lung adenocarcinoma presented as pure ground-glass opacity.Methods CT imaging features of 156 pGGO lesions which confirmed by surgery and pathology were analyzed in retrospectively.There were 58 lesions of pre-invasive (including atypical adenomatous hyperplasia and adenocarcinoma in situ),32 lesions of minimally invasive adenocarcinoma and 66 lesions of invasive adenocarcinoma.CT features were analyzed including lesion density,vacuole sign,air bronchogram and abnormal vascular changes (vascular dilatation,distortion or rigid).Results There were statistical difference in lesions density and abnormal vascular changes in 3 different pathological types (P ＜ 0.05),with increase of lesions invasive,the incidence of uneven density and abnormal vascular changes increase,its mean the more invasive of the lesion,the lesion tent to be more uneven and higher incidence of the dilation,twist or rigid of the vascular happened;while the incidence of the air bronchogram will be higher when the lesions invasive degree increased,but there was statistical difference only between the pre-invasive and invasive groups (including minimally invasive adenocarcinoma and invasive adenocarcinoma) (x2 =4.868,P =0.027).Conclusions The uneven density and abnormal vascular changes had certain value in differential diagnosis of lung adenocarcinoma presented as pGGO.

Objective To investigate the clinical value of high resolution vascular wall imaging(HRVWI)in the diagnosis and treatment of central nervous system vasculitis(CNSV)in children.Methods A total of 36 children with CNSV underwent HRVWI examination were selected.The HRVWI imaging features,involved vessel types and stenosis degree were analyzed retrospectively and compared with magnetic resonance angiography(MRA).Combined with some patients'follow-up and reviewed imaging after treatment.Results HRVWI showed that all of the 36 children with CNSV had cerebral arteritis,and the affected inflammatory ves-sels showed varying degrees of focal arterial wall thickening and enhancement,mainly uniform thickening and centripetal enhance-ment of the affected arterial wall.Most were mid-enhanced,and the stenosis degree was mostly at level 1(21/36).According to the type of involvement cerebrovascular,there were 26 cases of large-medium vessel type,6 cases of small vessel type and 4 cases of mixed type.Compared with MRA,HRVWI had a higher sensitivity in diagnosing CNSV(P＜0.05).13 cases were followed up after treat-ment,and HRVWI showed cerebral vasculitis relief in 8 cases and progression in 5 cases,consistent with changes in clinical symp-toms and laboratory indicators.Conclusion The imaging features of CNSV in children with different causes are different.HRVWI has a high sensitivity in the diagnosis of CNSV in children.HRVWI plays an important role in the diagnosis and treatment of CNSV in children.