KATHOLIEKE UNIVERSITEIT LEUVEN Faculty of Medicine Acute and Chronic Lung Disease W De Wever, JA Verschakelen Department of Radiology, University Hospitals Leuven, Belgium
Clinical utility of HRCT To detect lung disease patients who have symptoms suggestive of diffuse or acute lung disease patients who have normal or questionable radiographic abnormalities To make a specific diagnosis or limit the differential diagnosis To follow patients who are being treated, to monitor the success or failure of treatment As a guide for the need or optimal site and type of lung biopsy
Clinical utility of HRCT To detect lung disease patients who have symptoms suggestive of diffuse or acute lung disease patients who have normal or questionable radiographic abnormalities To make a specific diagnosis or limit the differential diagnosis To evaluate disease activity To follow patients who are being treated, to monitor the success or failure of treatment As a guide for the need or optimal site and type of lung biopsy
Assessment of disease activity and prognosis with HRCT HRCT may be used to distinguish between reversible (acute or active) lung disease and irreversible (fibrotic) lung disease A number of signs have been described as indicative of active or reversible and of chronic or irreversible lung disease
Signs on HRCT Acute lung diseases Chronic lung diseases Halo sign Air-crescent sign Ground-glass opacity Cystic lesions Consolidation Bronchiectasis Bronchial cuff sign Mucous plugging Traction bronchiectasis Tree-in-bud sign Nodules (centrilobular) Mosaic perfusion Nodules (perilymphatic) Linear and reticular opacities (smooth, without lung distortion) Linear and reticular opacities Nodular or irregular, with lung distortion) Honeycombing
Ground-glass opacity hazy increase in density of the lung with preservation of bronchial and vascular margins a number of pathologic conditions: incomplete filling of the alveolar space by cells or fluid minimal thickening of the interstitium or walls increased blood volume an ongoing, dynamic process that is potentially treatable
Clinical symptoms!!
Ground-glass opacity in the early stages of certain infectious processes in chronic diffuse lung diseases» Alveolar proteinosis» Chronic eosinophilic pneumonia in a number of interstitial diseases» IPF» Connective tissue diseases» EAA» Sarcoidosis» Drug induced pulmonary toxicity
Infectious disease Patients with altered immunity due to neoplasm and its treatment, AIDS or organ transplantation are subject to a wide variety of lung injuries that may be rapidly fatal if unrecognized Pneumocystic jirovecii pneumonia:» Spectrum of abnormalities» Ground-glass opacification is the earliest abnormality» Perihilar, asymmetric, mosaic pattern» Slight prominence of the interlobular interstitium, in the proximity of foci of ground-glass opacities» Cystic changes superimposed on ground-glass or consolidations are very suggestive
Infectious disease Patients with altered immunity due to neoplasm and its treatment, AIDS or organ transplantation are subject to a wide variety of lung injuries that may be rapidly fatal if unrecognized Bacterial and fungal infections:» CT features are not discriminating» Halo-sign Suggestive for early invasive aspergillosis Zone of hemorrhage or edema surrounding the fungal nodule or infarct» Air-crescent sign Recovery of granulocyte function
30/7/2003 3/1/2003
11/7/2003
18/8/2003 27/8/2003 15/10/2003 28/10/2003
Acute radiation pneumonitis Earliest findings within the irradiated field: ground-glass opacities heterogeneous consolidation Some degree of injury is typical with doses of 40 Gy or more
19/4/2002 4/9/2002 20/9/2002
Interstitial disease
5/6/2002
11/9/2003
EAA Acute stage: Corresponding to the initial exposure to the offending antigen HRCT can be normal or may reveal poorly defined air-space consolidations Subacute stage: Resolution of the acute abnormalities Small poorly marginated nodules from 1 5 mm diameter or scattered areas of ground-glass opacities bilateral Multi-local and random without preferential involvement of the central and peripheral lung regions Mid- and upper lobes are frequently affected Chronic stage: Interstitial fibrosis Irregular reticulation and nodularity Mid- and upper lung regions
29/12/2003
24/2/2004
2/6/2004
Bronchial and peribronchial abnormalities Abnormalities indicating airway disease Tree-in-bud pattern Acute disease Bronchiectasis Mosaic perfusion Acute - chronic disease Chronic disease
Tree-in-bud sign bronchiolar dilatation and filling by mucus, pus, fluid or cells resembling a branching or budding tree usually visible in the lung periphery patchy in distribution indicative of airways disease endobronchial spread of infection mucoid impaction (cystic fibrosis asthma ABPA)
Bronchiectasis Features of bronchiectasis: dilatation of the lumen signet ring sign airways visible in the peripheral one third of the lung bronchial wall thickening cystic and cylindric bronchiectasis traction bronchiectasis
8/1/2004
Mosaic perfusion Mixed areas of increased and decreased lung attenuation Primary vascular insult versus primary bronchial pathology
Disease Nodular opacities Acute Subacute Chronic Distribution Perilymphatic Centrilobular At random
Disease Nodular opacities Acute Subacute Chronic Distribution Perilymphatic patchy patchy Centrilobular diffuse or patchy diffuse or patchy At random diffuse diffuse
Disease Nodular opacities Acute Subacute Chronic Distribution Perilymphatic lymphangitic carcinomatosa sarcoidosis silicosis lymphangitic carcinomatosa Centrilobular infectious bronchiolitis EAA histiocytosis X - BAC At random miliary tbc miliary fungal disease metastasis
Linear and reticular opacities Smooth or regular (septal) lines without sings of lung distortion inflammatory changes, filling changes acute / subacute disease Nodular or irregular (septal) lines in combination with cystic changes, honeycombing and sings of lung distortion irreversible pulmonary fibrosis chronic disease
Linear and reticular opacities Smooth or regular (septal) lines without sings of lung distortion inflammatory changes, filling changes» pulmonary edema, lymphangitic carcinomatosis hemorrhage, amyloidosis, alveolar proteinosis Nodular or irregular (septal) lines in combination with cystic changes, honeycombing and sings of lung distortion irreversible pulmonary fibrosis» UIP, pneumoconiosis, sarcoidosis, asbestosis
20/11/2002
28/5/2003
26/11/2004
Cystic lesions Definition a thin-walled well-defined and circumscribed, air- or fluid-containing lesion, with an epithelial or fibrous wall A cystic pattern infectious disease (PJP) histiocytosis X lymphangioleiomyomatosis honeycombing
Conclusion HRCT may be used to distinguish between reversible (acute or active) lung disease and irreversible (fibrotic) lung disease A number of signs have been described as indicative of active or reversible and of chronic or irreversible lung disease
Signs on HRCT Acute lung diseases Chronic lung diseases Ground-glass opacity Consolidation Cystic lesions Mosaic perfusion Bronchial abnormalities Nodules (centrilobular) Nodules (perilymphatic) Linear and reticular opacities (smooth, without lung distortion) Linear and reticular opacities Nodular or irregular, with lung distortion) Honeycombing
Conclusion Radiologic interpretation of the different patterns Nodular Linear Increased lungattentuation Decreased lungattenuation Combined patterns Associated findings Radiologic interpretation within the context of clinical information