Objective To study the morphological appearance and pathological basis of the fine pulmonary reticulation at HRCT.Methods One hundred and seven patients were analyzed about the morphology findings and dynamic changes on pulmonary HRCT.Twenty-four coal worker's pneumoconiosis(CWP)specimens were examined to make comparison between CT and pathology.The data was analyzed by using the Chi-square test.Results The reticular gap was less than 3 mm in diameter.The morphology of reticulation was round or irregular.Pulmonary parenchyma was seen between the gaps.The reticular wall was smooth or coarse.The thickness was less than 1 mm.One hundred and seven patients had accompanying signs including ground-glass opacity(68.2%,73 patients),crazy paving(23.4%,25 patients),interlobular septal thickening(84.1%,90 patients),emphysema(32.7%,35 patients),interface sign(58.9%,63 patients),traction bronchiolectasis(41.1%,44 patients)and honeycombing(26.2%,28 patients).The differences of the honeycomb,traction bronchiolectosis,interbobular septal thickening,interface sign and paving were statistically significant between the fibrotic group and pneunonia(P＜0.01).Pneumonia showed extensive area of ground-glass opacity(GGO)with fine reticulation.Fine reticulation with both interlobular septal thickening and small nodules were observed more frequently in lmphangitic carcinomatosis.Idiopathic pulmonary fibrosis(IPF)showed fine reticulation among the honeycombing.Connective tissue disease (CTD)showed fine reticulation with rarely honeycombing and it could be partly absorbed.Fine reticulation with emphysema was seen in chronic bronchitis.In the 58 follow-up patients,the fine reticulation increased in 26 patients,decreased or disappeared in 22 patients and showed no change in 10 patients.The major pathological basis of the fine reticulation was intralobular interstitial thickening,including fibrosis hyperplasia,inflammatory cells and tumor cells infiltration,effusion filling,smut deposition and so on.Conclusions The fine reticulation was caused by intralobular interstitial thickening including inflammation,interstitial hyperplasia,pulmonary fibrosis and tumor.The fine reticulation is helpful to prompt the diagnosis of these diseases,but the diagnosis need its combination with the other CT findings and dynamic changes.

Objective TodetecttheCTfindingsofinterstitialpneumoniainacquiredimmunodeficiencysyndrome (AIDS)patients andtoanalyzedifferentialdiagnosisofdifferenttypesofinterstitialpneumonia.Methods Atotalof168 AIDSpatientswithinterstitial pneumoniabetweenOctober2016andJune2018 wereretrospectivelystudied.PulmonaryCTfindingsweredescribed.Results Among 168cases,44caseswerediagnosedaspneumocystiscariniipneumonia (PCP),40casesascytomegalovirus(CMV)pneumonia,and 84casesasPCPaccompaniedwithCMVpneumonia.Statisticallysignificantdifferenceswerefoundamong3groupsonsignsofpure groundglassopacity,accompaniedwithdistortedfibrousstripes,andaccompaniedwithconsolidationandmultiplecysts(P＜0.05). PuregroundglassopacitiesweremorelikelytobeseeninPCPpatients,whiledistortedfibrousstripeswerelesslikely,comparedto theothertwogroups.Militarynodules,consolidationandmultiplecystspresentedlessinpatientswithPCPcomparedtopatientswith PCPaccompaniedwithCMVpneumonia.ForPCPpatients,lesionsweremorelikelytobetotallyabsorbedaftertreatment,whilefor patientswithCMVpneumoniaandPCPaccompaniedwithCMVpneumonia,fibrousstripesandemphysema/airsacsweremorelikelyto present.Conclusion CTfindingsofinterstitialpneumoniavaryinAIDSpatients,however,signsofdistortedfibrousstripes,multiple cysts,remainingfibrousstripesandemphysema/airsacsaftertreatmentsuggestco-infectionofCMV.

Objective:To investigate the value of CT findings in predicting thetransformation of clinical types of COVID-19.Methods:From January 24 to February 6, 2020, the clinical and chest CT data of patients with common COVID-19 were analyzed retrospectively. A total of 64 patients were enrolled, including 32 males and 32 females, aged 18-76 (45±15) years. Based on the fact whether patients’ conditions had deteriorated into severe type, all the cases were divided into common type group (51 cases) and deteriorated type group (13 cases). Differences of CT findings in the two groups of patients were analyzed, and visual semi-quantitative scores were introduced to evaluate the pneumonia.Results:Compared with the common type group, the deteriorated type group was more likely to involve the left upper lobe, the right middle lobe and the lung far away from the pleura. The differences between the two groups were statistically significant (χ2= 5.897, P=0.027; χ2=8.549, P=0.005; χ2=10.169, P=0.002). The median of the involved lobes were 2 (1,5) in the common type group and 5 (4,5) in the deteriorated type group. The difference between the two groups was statistically significant (Z =-3.303, P=0.001). Taking the involved lobes ( n=4) as the threshold, the sensitivity and specificity of the diagnosis of the common type to the deteriorated type patients were the highest, 76.9% and 74.5% respectively, and the area under the ROC curve was 0.787. Pneumonia score of the deteriorated group was 10 (4,16), higher than that of the common group [4 (1,13)], and the difference was statistically significant ( Z=-4.040, P<0.001). Pneumonia score 8 as the threshold, the sensitivity and specificity of the general severe group were the highest, 69.2% and 86.3% respectively, and the area under ROC curve was 0.863. Conclusions:CT imaging has a profound value in the early prediction of deterioration in clinical type of COVID-19. It can help evaluate the severity of pneumonia in early stage. Range of lesions might be an important indicator for prognosis of common type COVID-19.