Management of Bilateral Interstitial Thickening on Chest X-Ray

Diagnostic Approach

The American College of Radiology recommends obtaining high-resolution CT (HRCT) immediately, as chest radiography has poor sensitivity (27-43.5%) for detecting early interstitial disease and cannot adequately characterize the pattern—HRCT is mandatory for diagnosis and will guide all subsequent management decisions 1
A comprehensive history should include occupational and environmental exposures, such as asbestos, silica, welding fumes, metal dust, organic antigens, and any industrial exposures, as these determine both diagnosis and prognosis 2, 3
The American Thoracic Society suggests that medication history, including molecular targeting agents, immune checkpoint inhibitors, mycophenolate mofetil, recent chemotherapy, amiodarone, nitrofurantoin, and methotrexate, should be explicitly inquired about, as drug-induced pneumonitis can present with bilateral interstitial patterns 4

The American College of Radiology states that HRCT chest without contrast is 91% sensitive and 71% specific for diagnosing ILD subtypes and is far superior to plain radiography, which misses up to 34% of cases 3, 1
The Fleischner Society recommends that HRCT pattern recognition should include usual interstitial pneumonia (UIP) pattern, characterized by bibasilar reticular abnormalities, honeycombing, traction bronchiectasis, and subpleural predominance, which suggests idiopathic pulmonary fibrosis if no identifiable cause 7

The American Thoracic Society suggests that antifibrotic therapy with nintedanib or pirfenidone should be initiated for idiopathic pulmonary fibrosis (UIP pattern, no identifiable cause), which slows annual FVC decline by approximately 44-57% and reduces disease progression 7
The European Respiratory Society recommends that immunomodulatory therapy, such as mycophenolate mofetil, rituximab, or tocilizumab, should be used for connective tissue disease-related ILD, which may slow decline or improve FVC at 12 months 7

The American College of Chest Physicians recommends that repeat HRCT should be performed within 3-6 months after diagnosis to determine rate of progression, then every 6-12 months for stable disease 7
The American Thoracic Society suggests that PFTs should be performed every 3-6 months for moderate-to-severe or progressive disease 7