What does an HRCT (High-Resolution Computed Tomography) scan showing cardiomegaly with interlobular septal thickening, peribronchial thickening, ground glassing, subsegmental consolidation, and pleural thickening indicate?

HRCT Findings Interpretation: Cardiac and Pulmonary Pathology

Your HRCT scan shows evidence of heart failure with pulmonary edema (fluid backing up into the lungs from the heart), along with a small area of lung collapse/infection in the left lower lobe. 1, 2

What Each Finding Means

Cardiomegaly (Enlarged Heart)

• The enlarged heart is the primary problem driving most of your lung findings. 1
• An enlarged heart often indicates chronic heart failure, where the heart cannot pump blood efficiently, causing fluid to back up into the lungs. 1

Interlobular Septal Thickening

• This represents fluid accumulation in the walls between lung units (Kerley lines), a classic sign of pulmonary edema from heart failure. 1, 3
• The European Society of Cardiology guidelines specifically identify "diffuse central ground-glass opacification and thickening of interlobular septa" as findings similar to those seen with advanced left ventricular failure. 1
• This pattern can also suggest pulmonary veno-occlusive disease if accompanied by lymphadenopathy and pleural effusions, though heart failure is more common. 1

Peribronchial Thickening

• This indicates fluid accumulation around the airways, another manifestation of pulmonary edema. 1
• Peribronchial thickening occurs when fluid leaks from congested pulmonary vessels into the tissue surrounding the bronchi. 1

Ground Glass Opacities (Ground Glassing)

• This hazy appearance represents either fluid in the air sacs (alveolar edema) or inflammation. 3, 4
• In the context of cardiomegaly and septal thickening, ground glass opacities most likely represent pulmonary edema rather than primary lung disease. 1, 3
• The American Thoracic Society notes that ground glass opacity appears as "a diffuse homogeneous increase in lung density where vessels and bronchial walls remain visible." 3

Subsegmental Consolidation/Collapse in Left Lower Lobe

• This small area of dense lung tissue in the posterior left lower lobe could represent either collapsed lung tissue (atelectasis) or pneumonia. 2, 4
• The posterior basal location suggests this may be dependent atelectasis (collapse from lying on your back), which is common and often benign. 2
• However, in the context of heart failure, this could also represent focal infection or aspiration. 4

Bilateral Pleural Thickening

• Thickening of the lung lining on both sides can indicate chronic fluid accumulation or inflammation. 1, 2
• HRCT can detect early pleural thickening (1-2mm thickness) with much higher sensitivity than plain radiographs. 1, 2
• In the context of cardiomegaly, this likely represents chronic pleural reaction to recurrent fluid accumulation. 1

Clinical Significance and Next Steps

The constellation of findings—cardiomegaly with septal thickening, ground glass opacities, and peribronchial thickening—strongly suggests congestive heart failure with pulmonary edema as the unifying diagnosis. 1, 3

Immediate Priorities

• Cardiac evaluation is essential: You need echocardiography to assess heart function, valve problems, and estimate pulmonary artery pressures. 1
• Assess for heart failure: Blood tests including BNP/NT-proBNP, ECG, and clinical assessment for heart failure symptoms (shortness of breath, leg swelling, orthopnea). 1
• Rule out infection: The left lower lobe consolidation may require clinical correlation, possibly sputum culture or bronchoscopy if infection is suspected. 4

Important Caveats

• Alternative diagnoses to consider if cardiac workup is normal: Pulmonary veno-occlusive disease (rare), pulmonary capillary hemangiomatosis (very rare), or early interstitial lung disease. 1
• The ground glass pattern could represent early fibrotic lung disease if cardiac function is normal, requiring different management with possible immunosuppression or antifibrotic therapy. 3, 4
• Prone HRCT images would help distinguish true fibrosis from dependent atelectasis in the posterior lung fields, which is critical for accurate diagnosis. 2

Follow-up Imaging

• Repeat HRCT after cardiac optimization (diuresis, heart failure treatment) would clarify which findings are reversible versus representing permanent structural changes. 2, 5
• If findings persist despite optimal heart failure management, consider evaluation for interstitial lung disease with pulmonary function tests and possible multidisciplinary discussion. 2, 4