Morphological analysis and pathological basis of the fine pulmonary reticulation at high-resolution CT

Abstract

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. Key words: Pneumoconiosis; Tomography,X-ray computed; Pathology